Patent Publication Number: US-2022236802-A1

Title: Input feedback based smart pen and protruding feedback based smart tablet

Description:
TECHNICAL FIELD 
     The present disclosure relates to an input feedback-based smart pen and a protruding feedback-based smart tablet. 
     BACKGROUND ART 
     Users may perceive information in various ways. For this purpose, various types of information output devices are used. 
     For example, an apparatus for outputting visual information using printed materials, an apparatus for outputting audio information through sound, etc. are being used. 
     Meanwhile, users may perform input operations through manipulations in various forms according to their intentions. For example, a user may write or draw on paper by using a pen. 
     As a result of such an input operation, for example, text or a drawing may be visually recognized. 
     However, when a result of such an input operation is directly sensed, for example, there are cases in which it is difficult to visually detect a text or a drawing written on paper. and thus there is a limit of improving user convenience regarding sensing of a result of an input operation of a user. 
     On the other hand, due to technological development and diversification of lifestyles, various types of information output formats are required. 
     In addition, it is required to output such that the content input by the user can be detected at the time of such output. 
     For example, various information output devices may be demanded according to situations of users, and more particularly, it is demanded to tactilely output information as a feedback to an input content for a user with a specific sensory handicap, e.g., visual handicap. When information is output tactilely, it is difficult to control the output easily and stably, and thus there is a limit of improving user conveniences through the improvement of information output devices. 
     DESCRIPTION OF EMBODIMENTS 
     Technical Problem 
     Embodiments of the present disclosure provide an input feedback-based smart pen capable of improving user convenience by facilitating a feedback on a users input operation. 
     Embodiments of the present disclosure provide a protruding feedback-based smart tablet that allows a user to easily sense output information corresponding to an input and improves user convenience. 
     Solution to Problem 
     According to an embodiment of the present disclosure, an input feedback-based smart pen includes a main body having a shape that enables manipulation of a user; an input unit connected to the main body and performing an input operation by a manipulation of the user; an input information recognition unit configured to recognize information input by a user through the manipulation of the input unit; and an expression unit including one or more expression members formed in an area of an outer surface of the main body to be detectable by the user to express information corresponding to input information recognized by the input information recognition unit. 
     According to the present embodiment, the input feedback-based smart pen may further include an information processing unit configured to process one or more pieces of information by using contents recognized by the input information recognition unit and delivers processed information to the expression unit. 
     According to the present embodiment, the input feedback-based smart pen may further include an operation control unit formed to be manipulated by a user to control one or more operations regarding the expression unit. 
     According to the present embodiment, the expression unit may include a plurality of expression members, and different information may be delivered to a user according to protruding shapes of the plurality of expression members. According to the present embodiment, the input feedback-based smart pen may further include a speaker configured to output the one or more pieces of information. 
     According to an embodiment of the present disclosure, a protruding feedback-based smart tablet includes one or more output units, wherein the protruding feedback-based smart tablet includes an expression area in which one or more output units are arranged, and the one or more output units each includes an expression unit formed and disposed to be sensible by a user and formed to protrude in response to a movement of an input pen when the user performs an input operation on the expression area by using the input pen. 
     According to the present embodiment, the input pen may include one or more magnetic bodies, and the expression unit may move by a magnetic field generated by the one or more magnetic bodies. 
     According to the present embodiment, the output unit may include a magnetic body to generate a magnetic field together with the one or more magnetic bodies of the input pen. 
     According to the present embodiment, the expression unit protruded by the input pen of the user may maintain a protruding state even when the input pen of the user is removed. 
     According to the present embodiment, the protruding feedback-based smart tablet may further include a reset member configured to release a protruding state of the expression unit to maintain a non-protruding state of the expression unit. 
     According to the present embodiment, the reset member may control a movement for the expression unit by using a magnetic field. 
     According to the present embodiment, the reset member may simultaneously release a protruding state of a plurality of expression units to maintain a non-protruding state of the expression units. 
     Other aspects, features, and advantages will become apparent from the following drawings, claims, and detailed description of the invention. 
     Effects of the Invention 
     An input feedback-based smart pen according to the present embodiment may improve user convenience by facilitating feedback on a user&#39;s input operation. 
     A protruding feedback-based smart tablet according to the present embodiment may facilitate a user to sense output information corresponding to an input by the user and improve user convenience. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram showing an input feedback-based smart pen according to an embodiment of the present disclosure. 
         FIG. 2  is a diagram showing a modified example of an input recognition unit of the input feedback-based smart pen of  FIG. 1 . 
         FIG. 3  is a diagram showing another modified example of an input recognition unit of the input feedback-based smart pen of  FIG. 1 . 
         FIG. 4  is an enlarged view to describe an expression unit of the input feedback-based smart pen of  FIG. 1 . 
         FIG. 5  is a cross-sectional view taken along a line V-V of  FIG. 4 . 
         FIG. 6  is a diagram showing an optional embodiment of the expression unit of  FIG. 4 . 
         FIG. 7  is a diagram showing another selective embodiment of the expression unit of  FIG. 4 . 
         FIG. 8  is a diagram showing an example in which a user uses the user input feedback-based smart pen of  FIG. 1 . 
         FIG. 9  is an enlarged view of an area of  FIG. 8 . 
         FIG. 10  is a diagram showing an input feedback-based smart pen according to another embodiment of the present disclosure. 
         FIG. 11  is a diagram showing an input feedback-based smart pen according to another embodiment of the present disclosure. 
         FIG. 12  is a diagram showing an input feedback-based smart pen according to another embodiment of the present disclosure. 
         FIGS. 13 to 17  are diagrams showing examples of use of the input feedback-based smart pen of  FIG. 12 . 
         FIG. 18  is a diagram for schematically describing a protruding feedback-based smart tablet according to an embodiment of the present disclosure. 
         FIGS. 19 and 20  are views of an input pen shown in  FIG. 18 . 
         FIGS. 21 and 22  are diagrams for describing the operation of the protruding feedback-based smart tablet of  FIG. 18 . 
         FIG. 23  is a cross-sectional view taken along a line VI-VI of  FIG. 21 . 
         FIG. 24  is an exploded perspective view of one output unit of  FIG. 21  for convenience of explanation. 
         FIG. 25  is a schematic perspective view of an expression unit of an output unit of  FIG. 23 . 
         FIG. 26  is a schematic front view of the expression unit of the output unit of  FIG. 23 . 
         FIG. 27  is a perspective view taken in a direction different from that of  FIG. 25 . 
         FIG. 28  is a schematic bottom view of the expression unit of the output unit of  FIG. 23 . 
         FIG. 29  is a front view of an expression unit and an expression unit insert of the output unit of  FIG. 23 . 
         FIGS. 30 and 31  are front views of other modified examples of the expression unit of the output unit of  FIG. 23 . 
         FIG. 32  is a schematic perspective view of a moving unit of the output unit of  FIG. 23 . 
         FIG. 33  is a schematic plan view of the moving unit of the output unit of  FIG. 23 . 
         FIG. 34  is a perspective view taken in a direction different from that of  FIG. 32 . 
         FIG. 35  is a schematic perspective view of a base unit of the output unit of  FIG. 23 . 
         FIG. 36  is a schematic plan view of the base unit of the output unit of  FIG. 23 . 
         FIG. 37  is a perspective view taken in a direction different from that of  FIG. 35 . 
         FIGS. 38A to 38E  are diagrams for describing an example of the operation of the output unit of  FIG. 23 . 
         FIGS. 39 to 41  are diagrams for describing an example of arrangements and shapes of a reset member. 
         FIG. 42  is a diagram for explaining an output unit according to another embodiment of the present disclosure. 
         FIG. 43  is an enlarged view of a portion of  FIG. 42 . 
         FIGS. 44A to 44D  are diagrams for describing the operation of the output unit of  FIG. 42 . 
         FIG. 45  is a perspective view of a modified example of the output unit of  FIG. 42 . 
         FIG. 46  is an enlarged view of a portion of  FIG. 45 . 
         FIGS. 47 and 48  are views of modified examples of a driving expression unit. 
         FIG. 49  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
         FIG. 50  is an enlarged view of a driving expression unit of  FIG. 49 . 
         FIG. 51  is a perspective plan view of the driving expression unit of  FIG. 49  viewed from above. 
         FIG. 52  is an enlarged view of a modified example of the driving expression unit of  FIG. 49 . 
         FIG. 53  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
         FIGS. 54 and 55  are diagrams for describing the operation of the output unit of  FIG. 53 . 
         FIG. 56  is a schematic perspective view of an output unit according to another embodiment of the present disclosure. 
         FIG. 57  is a cross-sectional view taken along a line V-V of  FIG. 56 . 
         FIG. 58  is a cross-sectional view taken along a line VI-VI of  FIG. 56 . 
         FIG. 59  is a schematic perspective view for describing the driving unit of  FIG. 56 . 
         FIG. 60  is a front view of the driving unit viewed from one direction of  FIG. 59 . 
         FIG. 61  is a partial perspective view of an area of a base unit of  FIG. 56  viewed from one direction. 
         FIGS. 62A and 62B  are views of a support unit of the output unit of  FIG. 56  and a modified example thereof. 
         FIGS. 63 and 64  are views of an expression unit of  FIG. 56  and a modified example thereof. 
         FIG. 65  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
         FIG. 66  is a diagram for describing a driving unit of  FIG. 65 . 
         FIG. 67  is a diagram for describing a guide groove of the output unit of  FIG. 65 . 
         FIGS. 68A and 68B  are views of a support unit of the output unit of  FIG. 65  and a modified example thereof. 
         FIGS. 69A and 69B  are views of an expression unit of the output unit of  FIG. 65  and a modified example thereof. 
         FIGS. 70 to 73  are diagrams for describing the operation of the output unit of  FIG. 65 . 
         FIG. 74  is a schematic perspective view of an output unit according to another embodiment of the present disclosure. 
         FIG. 75  is a schematic front view viewed from one direction of  FIG. 74 . 
         FIG. 76  is a diagram for describing a driving unit of  FIG. 74 . 
         FIG. 77  is a cross-sectional view taken along a line XI-XI of  FIG. 76 . 
         FIGS. 78 and 79  are schematic front views of the operation of an output unit according to another embodiment of the present disclosure. 
         FIG. 80  is a side view viewed in a direction A of  FIG. 78 . 
         FIG. 81  is a schematic front view of the operation of an output unit according to another embodiment of the present disclosure. 
         FIG. 82  is a diagram for describing a driving unit of  FIG. 81 . 
         FIG. 83  is a diagram showing one of selective embodiments of the driving unit of  FIG. 81 . 
         FIG. 84  is a diagram for describing a guide groove of  FIG. 81 . 
         FIGS. 85 and 86  are diagrams for describing the operation of an information output device of  FIG. 81 . 
         FIG. 87  is a schematic perspective view of the operation of an output unit according to another embodiment of the present disclosure. 
         FIG. 88  is a side view viewed in one direction of  FIG. 87 . 
         FIGS. 89 and 90  are diagrams for describing a protruding feedback-based smart tablet and a reset member according to another embodiment of the present disclosure. 
         FIG. 91  is a diagram for schematically describing a protruding feedback-based smart tablet according to another embodiment of the present disclosure. 
         FIG. 92  is an enlarged view of an area of the protruding feedback-based smart tablet  FIG. 91 . 
         FIG. 93  is a cross-sectional view taken along a line XX-XX of  FIG. 92 . 
         FIG. 94  is a diagram for explaining an output unit according to another embodiment of the present disclosure. 
         FIG. 95  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
         FIG. 96  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
         FIG. 97  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
     
    
    
     MODE OF DISCLOSURE 
     The present disclosure may include various embodiments and modifications, and embodiments thereof will be illustrated in the drawings and will be described herein in detail. The effects and features of the present disclosure and the accompanying methods thereof will become apparent from the following description of the embodiments, taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments described below, and may be embodied in various modes. 
     Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the drawings, the same elements are denoted by the same reference numerals, and a repeated explanation thereof will not be given. 
     It will be understood that although the terms “first”, “second”, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These elements are only used to distinguish one element from another. 
     As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     It will be further understood that the terms “comprises” and/or “comprising” used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components. 
     Sizes of elements in the drawings may be exaggerated for convenience of explanation. In other words, since sizes and thicknesses of components in the drawings are arbitrarily illustrated for convenience of explanation, the following embodiments are not limited thereto. 
     In the following examples, the x-axis, the y-axis and the z-axis are not limited to three axes of the rectangular coordinate system, and may be interpreted in a broader sense. For example, the x-axis, the y-axis, and the z-axis may be perpendicular to one another, or may represent different directions that are not perpendicular to one another. 
     When a certain embodiment may be implemented differently, a specific process order may be performed differently from the described order. For example, two consecutively described processes may be performed substantially at the same time or performed in an order opposite to the described order. 
       FIG. 1  is a diagram showing an input feedback-based smart pen according to an embodiment of the present disclosure. 
     An input feedback-based smart pen  100  of the present embodiment may include a main body  101 , an input unit  110 , an input information recognition unit  120 , and an expression unit  150 . 
     The main body  101  may have a shape that enables manipulation of a user. For example, the main body  101  may have a pillar-like shape to be held by a user, and, as a specific example, may have a cylindrical shape, a prismatic shape, or an elliptical pillar-like shape. 
     Alternatively, to facilitate a user to perform an input operation, the main body  101  may have various shapes and employ shapes of various types of pens. 
     When a user manipulates an input feedback main body  101 , the user may hold the main body  101  by a hand, and, in this case, a top end  102  including an uppermost region located over the upper portion of the main body  101 . 
     According to an optional embodiment, the top end  102  may include a region formed to be thinner than the main body  101 , and, although not shown, according to another embodiment, a hook or a handle may be further formed at the top end  102  to improve user convenience. 
     The input unit  110  is connected to the main body  101  and may perform an input operation by a manipulation of a user. The input unit  110  may allow visual expression of forms like characters or drawings on a medium like paper. For example, the input unit  110  may have a shape similar to a portion of a ballpoint pen lead, a pencil lead, or a felt pen. 
     According to an optional embodiment, a result of an input operation of the input unit  110  may not be visually displayed on a medium like paper. For example, when there is an input operation of a user using the input unit  110 , information regarding changes due to the movement of the input unit  110  may be recognized by the input information recognition unit  120  to be described later as a result of the input operation. 
     In this case, the input unit  110  may not need to separately provide a lead like a pencil lead, a ballpoint pen lead, or a felt pen. 
     The input information recognition unit  120  may recognize information input by a user by manipulating the input unit  110 . 
     For example, when a user draws letters and/or drawings or performs various input operations on paper by using the input unit  110 , the input information recognition unit  120  may recognizes visually identifiable information like letters, drawings, or figures drawn on the paper. 
     As an optional embodiment, the input information recognition unit  120  may include an optical member, for example, a photographing member. 
     As shown in  FIG. 1 , the input information recognition unit  120  may be formed in one area of the main body  101 . For example, the input information recognition unit  120  may be formed at the bottom end of the main body  101 . 
       FIG. 2  is a diagram showing a modified example of an input recognition unit of the input feedback-based smart pen of  FIG. 1 . 
     Referring to  FIG. 2 , the input information recognition unit  120 ′ may be disposed adjacent to the input unit  110  and may be disposed to face the input unit  110 . 
     For example, the input information recognition unit  120 ′ may be formed at the bottom end of the main body  101 . In detail, the input information recognition unit  120 ′ may be formed in one area of the bottom portion of the main body  101 . 
       FIG. 3  is a diagram showing another modified example of an input recognition unit of the input feedback-based smart pen of  FIG. 1 . 
     Referring to  FIG. 3 , an input information recognition unit  120 ″ may be disposed above the input unit  110 . For example, the input information recognition unit  120 ″ may be disposed in an area adjacent to the top end  102 . 
     According to an optional embodiment, the input information recognition unit  120 ″ may be formed to be located above a user&#39;s hand to not to overlap the user&#39;s hand when the user holds the main body  101 . 
     Input information recognition units  120 ,  120 ′, and  120 ″ of  FIGS. 1 to 3  may each include a photographing member for recognizing visual information as described above, and, in this case, at least one member, e.g., an imaging device, may be disposed inside the main body  101 . 
     According to an optional embodiment, the input information recognition unit  120  may include a motion detecting sensor to detect an input by the input unit  110 . For example, when a user moves the input unit  110  to write a character by using the input unit  110 , the movement of the input unit  110  may be detected. According to an optional embodiment, as described above, a result of an input operation using the input unit  110  may not be visually displayed. In this case, the input information recognition unit  120  including the motion detecting sensor may easily detect an input made by using the input unit  110 . 
     The selective embodiment of  FIGS. 2 and 3  may be applied to the input information recognition unit  120  including such a motion detecting sensor. However, for precise detection of the movement of the input unit  110  through a user&#39;s motion, the motion detection sensor of the input information recognition unit  120  may be provided close to the input unit  110 . 
     According to an optional embodiment, the motion detecting sensor of the input information recognition unit  120  may not be exposed to the outside. For example, the motion detecting sensor may be disposed inside the main body  101 . Alternatively, the input information recognition unit  120  may be formed inside or on one side of the input unit  110  through fine formation. 
       FIG. 4  is an enlarged view to describe an expression unit of the input feedback-based smart pen of  FIG. 1 , and  FIG. 5  is a cross-sectional view taken along a line V-V of  FIG. 4 . 
     The expression unit  150  may be disposed on an area of the outer surface of the main body  101  to express information corresponding to input information recognized by the input information recognition unit  120 . 
     The expression unit  150  may be formed to be recognizable by a user. For example, the expression unit  150  may be formed in correspondence to a finger of a user. 
     The expression unit  150  may include one or more expression members  152  to be recognizable by a user. For example, the expression unit  150  may include a plurality of expression members  152 . 
     The expression member  152  may be formed to be recognizable by a user by moving to protrude toward at least one area of a finger of the user. 
     The expression unit  150  may express content input by a user through the input unit  110 . For example, when a user inputs a character through the input unit  110 , the input information recognition unit  120  may recognize the input in various ways as described above. Recognized information may be expressed by the expression unit  150 , and the user may sense an expression of the expression unit  150 . 
     Therefore, the user may sense information about contents input through the input unit  110 . 
     According to an optional embodiment, when a user is visually handicapped with no vision or very weak eyes, it may not be easy to visually confirm even content that the user inputs through the input unit  110 . According to the present embodiment, in such a case, the expression unit  150  may allow a user to confirm an input by allowing the user to sense information about the input through protrusion of the expression member  152 . 
     As a specific example, when a user intends to input the character “san (mountain)” through the input unit  110 , the input information recognition unit  120  may recognize content of the input through the input unit  110 , the expression unit  150  may express the content to allow the user to sense an expression thereof, and, even when it is difficult for the user to visually confirm the input made by the user due to visual handicap, the user may confirm the input by sensing protrusion of the expression member  152  of the expression unit  150 . The protrusion of the expression member  152  may correspond to a type of Braille. For example, when “san (mountain)” is input through the input unit  110 , the expression member  152  of the expression unit  150  may have a protruding shape to express “mountain” in Braille. 
     According to an optional embodiment, an information processing unit  130  may be further provided, and the information processing unit  130  may process various information by using information recognized by the input information recognition unit  120  and transmit processed information to the expression unit  150 . 
     For example, the information processing unit  130  may process Braille information regarding an input made by a user. 
     Also, according to another embodiment, the information processing unit  130  may process voice information regarding an input made by a user. 
     According to an optional embodiment, the information processing unit  130  may include a storage unit for storing one or more pieces of Braille data information. 
     According to an optional embodiment, the information processing unit  130  may include a character determiner, a figure determiner, etc. for determining an input made by a user and may include a database for this purpose. 
     Also, as an additional example, the information processing unit  130  may include a text information conversion control unit for converting input information into text information. 
     According to an optional embodiment, when a user inputs a character, the information processing unit  130  may process expression information for a correct answer or an incorrect answer by determining whether the character input by the user is a correct character or not. 
     The expression unit  150  may be implemented in various forms. For example, the plurality of expression members  152  of the expression unit  150  may be arranged in correspondence to through holes  151 H of a base  151 , respectively, and may be sensed by fingers of a user by protruding out of the through holes  151 H or receding into the through holes  151 H. 
     Referring to  FIG. 5 , for example, the expression member  152  may be moved by a drive providing member MU. 
     According to an optional embodiment, the drive providing member MU may include one or more drive sources COI, e.g., a coil. Also, according to an optional embodiment, the drive sources COI may include a magnet. As a specific example, the drive sources COI may include a coil surrounding a magnet. 
     According to an optional embodiment, the drive providing member MU may include a moving member DRU that is moved by the drive source COI, and the expression member  152  may protrude through the movement of the moving member DRU. 
     According to an optional embodiment, for example, a current may be applied to the coil of the drive source COI including a coil of the drive providing member MU, and the moving member DRU may be moved by a magnetic field generated around the coil of the drive source COI at this time. 
     According to an optional embodiment, the moving member DRU may include a magnetic unit. According to another embodiment, the moving member DRU may include a magnet. 
     According to an optional embodiment, the moving member DRU may be integrally formed with the expression member  152  or the moving member DRU may be disposed inside the expression member  152 . 
       FIG. 6  is a diagram showing an optional embodiment of the expression unit of  FIG. 4 , and  FIG. 7  is a diagram showing another selective embodiment of the expression unit of  FIG. 4 . 
     Referring to  FIG. 6 , an expression unit  150 ′ may include a plurality of expression members  152 ′ formed to be spaced apart from one another on one surface of a base  151 ′. 
     The plurality of expression members  152 ′ may be arranged in correspondence with a plurality of through holes  151 H″ of the base  151 ′ and may be arranged to be spaced apart from one another. 
     Referring to  FIG. 7 , an expression unit  150 ″ may include a plurality of expression members  152 ″ formed to be spaced apart from one another on one surface of a base  151 ″. 
     The plurality of expression members  152 ″ may be arranged in correspondence with a plurality of through holes  151 H″ of the base  151 ″ and may be arranged to be spaced apart from one another. 
     The base  151 ″ may include a curved surface. For example, the base  151 ″ may include a curved surface in correspondence with a curved surface of the outer surface of the main body  101  shown in  FIG. 1 , and the plurality of expression members  152 ″ may be arranged along the curved surface. 
       FIG. 8  is a diagram showing an example in which a user uses the user input feedback-based smart pen of  FIG. 1 , and  FIG. 9  is an enlarged view of an area of  FIG. 8 . 
       FIGS. 8 and 9  shows that a user performs an input operation by manipulating the input feedback-based smart pen  100  using a hand HDU.  FIG. 8  shows that an input content DI includes, for example, a character, and specifically, a character “san (mountain)”. 
     As a result of an input operation by manipulating the input feedback-based smart pen  100 , the input content DI may be visually confirmed. For example, the input content DI may be displayed by the input unit  110  to be visually recognizable on a medium like a piece of paper. 
     Also, according to an optional embodiment, the input content DI may not be visible even when the input unit  110  is operated by manipulating the input feedback-based smart pen  100 , and information regarding a movement of the input unit  110  for inputting the input content DI, e.g., a position of the input unit  110 , a trace of the movement of the input unit  110 , etc., may be recognized by the input information recognition unit  120 . 
     The input information recognition unit  120  may recognize the input content DI input through the input unit  110 , and the expression unit  150  may express such information to be recognized by the user. 
     For example, the expression unit  150  may control the protrusion of the plurality of expression members  152  of the expression unit  150 , and the protrusion of the expression member  152  may be sensed by the user. For example, a finger from between fingers HF 1  and HF 2  of the user, (more specifically, the index finger HF 1 ) may sense the protrusion. For example, by using the protrusion of the plurality of expression members  152 , a user may recognize the input content DI (more specifically, information “san (mountain)”) through the index finger HF 1 . 
     According to an optional embodiment, the meaning of “mountain” may be delivered in the form of Braille through the plurality of expression members  152 . 
     Also, according to an optional embodiment, instead of directly delivering the meaning of “mountain” through the plurality of expression members  152 , indirect information (as specific examples, “correct answer” or “incorrect answer”) may be delivered. This may correspond to a case of notifying a user of “correct” when the input content DI input by the user using the input unit  110  includes correctly written character “san (mountain)” and notifying “wrong” otherwise. 
     In addition, according to an optional embodiment, after allowing a user to input an answer fora set problem, the meaning of a correct answer or an incorrect answer for an input content may be delivered. In this case, such a set problem may be delivered through voice. In another example, such a set problem may also be delivered, for example, through the expression members  152  of the expression unit  150 , e.g., in the form of Braille. 
     An input feedback-based smart pen of the present embodiment enables a user to hold a main body, thereby facilitating an input operation through an input unit. At this time, as a result of the input operation, an input content may be visually displayed on paper like in the case of using an actual pencil or pen or may not be displayed. An input information recognition unit may recognize such input contents, and an expression unit may express recognized information. According to an optional embodiment, one or more pieces of processed information, e.g., Braille information, information indicating a correct answer or an incorrect answer, etc., may be transmitted to an expression unit based on information recognized by an input information recognition unit and made recognizable by a user through protrusion of one or more expression members of an expression unit. 
     With respect to a content input by a user through an input unit, the user may confirm information input by the user by detecting a protruding shape of expression members of an expression unit immediately or a short time after the input. For example, it may not be easy for a user with visual handicap to confirm information input by the user. In this case, an expression unit facilitates confirmation of the information. 
     Also, even a user who has not yet mastered characters may easily sense whether an input is correct or incorrect in the course of practicing characters through an expression unit. Here, the expression unit may express a correct answer and an incorrect answer in different pre-set protruding shapes of expression members other than in the form of Braille, thereby facilitating a user to recognize an expression indicating a correct answer or an incorrect answer. 
     Through this, it is possible to easily provide feedbacks on information input by users in various conditions, thereby improving user convenience of confirming and learning information. 
     Although not shown, a power supply for the operation of an expression unit or an input information recognition unit may be included, wherein the power supply may include a built-in battery, a rechargeable battery, or an external power connection unit. 
       FIG. 10  is a diagram showing an input feedback-based smart pen according to another embodiment of the present disclosure. 
     An input feedback-based smart pen  200  of the present embodiment may include a main body  201 , an input unit  210 , an input information recognition unit  220 , an expression unit  250 , and an operation control unit  260 . 
     For convenience of explanation, descriptions below will focus on differences from the above-described embodiment. 
     The main body  201  may have a shape that enables manipulation of a user. For example, the main body  201  may have a pillar-like shape to be held by a user, and, as a specific example, may have a cylindrical shape, a prismatic shape, or an elliptical pillar-like shape. 
     When a user manipulates an input feedback main body  201 , the user may hold the main body  201  by a hand, and, in this case, a top end  202  including an uppermost region located over the upper portion of the main body  201 . 
     According to an optional embodiment, the top end  202  may include a region formed to be thinner than the main body  201 , and, although not shown, according to another embodiment, a hook or a handle may be further formed at the top end  202  to improve user convenience. 
     The input unit  210  is connected to the main body  201  and may perform an input operation by a manipulation of a user. The input unit  210  may allow visual expression of forms like characters or drawings on a medium like paper. For example, the input unit  210  may have a shape similar to a portion of a ballpoint pen lead, a pencil lead, or a felt pen. 
     According to an optional embodiment, a result of an input operation of the input unit  210  may not be visually displayed on a medium like paper. For example, when there is an input operation of a user using the input unit  210 , information regarding changes due to the movement of the input unit  210  may be recognized by the input information recognition unit  220  to be described later as a result of the input operation. 
     In this case, the input unit  210  may not need to separately provide a lead like a pencil lead, a ballpoint pen lead, or a felt pen. 
     The input information recognition unit  220  may recognize information input by a user by manipulating the input unit  210 . 
     For example, when a user draws letters and/or drawings or performs various input operations on paper by using the input unit  210 , the input information recognition unit  220  may recognizes visually identifiable information like letters, drawings, or figures drawn on the paper. 
     According to an optional embodiment, the input information recognition unit  220  may include an optical member, e.g., a photographing member. 
     As shown in  FIG. 10 , the input information recognition unit  220  may be formed in one area of the main body  201 . For example, the input information recognition unit  220  may be formed at the bottom end of the main body  201 . 
     According to an optional embodiment, the examples of  FIGS. 2 and 3  may be applied. 
     According to an optional embodiment, the input information recognition unit  220  may include a motion detecting sensor to detect an input by the input unit  210 . For example, when a user moves the input unit  210  to write a character by using the input unit  210 , the movement of the input unit  210  may be detected. According to an optional embodiment, as described above, a result of an input operation using the input unit  210  may not be visually displayed. In this case, the input information recognition unit  220  including the motion detecting sensor may easily detect an input made by using the input unit  210 . 
     According to an optional embodiment, the motion detecting sensor of the input information recognition unit  220  may not be exposed to the outside. For example, the motion detecting sensor may be disposed inside the main body  201 . Alternatively, the input information recognition unit  220  may be formed inside or on one side of the input unit  210  through fine formation. 
     The expression unit  250  may be disposed on an area of the outer surface of the main body  201  to express information corresponding to input information recognized by the input information recognition unit  220 . 
     The expression unit  250  may be formed to be recognizable by a user. For example, the expression unit  250  may be formed in correspondence to a finger of a user. 
     The expression unit  250  may include one or more expression members to be recognizable by a user. For example, the expression unit  250  may include a plurality of expression members. 
     The expression member may be formed to be recognizable by a user by moving to protrude toward at least one area of a finger of the user. 
     Although not shown, the structures of  FIGS. 4 and 5  may also be applied to the present embodiment. 
     The expression unit  250  may express content input by a user through the input unit  210 . For example, when a user inputs a character through the input unit  210 , the input information recognition unit  220  may recognize the input in various ways as described above. Recognized information may be expressed by the expression unit  250 , and the user may sense an expression of the expression unit  250 . 
     Therefore, the user may sense information about contents input through the input unit  210 . 
     According to an optional embodiment, when a user is visually handicapped with no vision or very weak eyes, it may not be easy to visually confirm even content that the user inputs through the input unit  210 . According to the present embodiment, in such a case, the expression unit  250  may allow a user to confirm an input by allowing the user to sense information about the input through protrusion of the expression member. 
     As a specific example, when a user intends to input the character “san (mountain)” through the input unit  210 , the input information recognition unit  220  may recognize content of the input through the input unit  210 , the expression unit  250  may express the content to allow the user to sense an expression thereof, and, even when it is difficult for the user to visually confirm the input made by the user due to visual handicap, the user may confirm the input by sensing protrusion of the expression member (not shown) of the expression unit  250 . The protrusion of the expression member (not shown) may correspond to a type of Braille. For example, when “san (mountain)” is input through the input unit  210 , the expression member (not shown) of the expression unit  250  may have a protruding shape to express “mountain” in Braille. 
     According to an optional embodiment, an information processing unit  230  may be further provided, and the information processing unit  230  may process various information by using information recognized by the input information recognition unit  220  and transmit processed information to the expression unit  250 . 
     For example, the information processing unit  230  may process Braille information regarding an input made by a user. 
     Also, according to another embodiment, the information processing unit  230  may process voice information regarding an input made by a user. 
     According to an optional embodiment, the information processing unit  230  may include a storage unit for storing one or more pieces of Braille data information. 
     According to an optional embodiment, the information processing unit  230  may include a character determiner, a figure determiner, etc. for determining an input made by a user and may include a database for this purpose. 
     Also, as an additional example, the information processing unit  130  may include a text information conversion control unit for converting input information into text information. 
     According to an optional embodiment, when a user inputs a character, the information processing unit  230  may process expression information for a correct answer or an incorrect answer by determining whether the character input by the user is a correct character or not. 
     The expression unit  250  may be implemented in various forms. For example, the plurality of expression members (not shown) of the expression unit  250  may be arranged in correspondence to through holes (not shown) of a base (not shown), respectively, and may be sensed by fingers of a user by protruding out of the through holes (not shown) or receding into the through holes (not shown). 
     Also, although not shown, the structure of  FIG. 6  or  FIG. 7  may be applied as an optional embodiment. 
     The operation control unit  260  may control one or more operations of the expression unit  250  through a user&#39;s manipulation. 
     For example, the operation control unit  260  may initiate an operation of initializing the expression members (not shown) of the expression unit  250 . More specifically, when the expression members (not shown) are being protruded, all of the expression members (not shown) may be returned to an original state, that is, non-protruding state, by manipulation of a user. 
     According to an optional embodiment, the operation control unit  260  may generate a preparation signal for the expression unit  250 . For example, a user may operate the operation control unit  260  before making an input through the input unit  210 . Only when a preparation signal of the operation control unit  260  is generated, the input information recognition unit  220  may perform recognition on an input operation of the input unit  210 , and the expression unit  250  may perform an expression using a recognized content. Therefore, the efficiency of the operation of the input feedback-based smart pen  200  may be improved and power consumption may be reduced. 
     As described above, for example, as shown in  FIGS. 8 and 9 , a user may manipulate the input feedback-based smart pen  200  by using his/her hand to perform an input operation, an input content may be recognized by the input information recognition unit  220  as a result of the input operation, the protrusion of a plurality of expression members of the expression unit  250  may be controlled in response thereto, and the user may sense the protrusion of the expression members. For example, one of the user&#39;s fingers (more specifically, the index finger) may sense the protrusion. 
     An input feedback-based smart pen of the present embodiment enables a user to hold a main body, thereby facilitating an input operation through an input unit. At this time, as a result of the input operation, an input content may be visually displayed on paper like in the case of using an actual pencil or pen or may not be displayed. An input information recognition unit may recognize such input contents, and an expression unit may express recognized information. According to an optional embodiment, one or more pieces of processed information, e.g., Braille information, information indicating a correct answer or an incorrect answer, etc., may be transmitted to an expression unit based on information recognized by an input information recognition unit and made recognizable by a user through protrusion of one or more expression members of an expression unit. 
     With respect to a content input by a user through an input unit, the user may confirm information input by the user by detecting a protruding shape of expression members of an expression unit immediately or a short time after the input. For example, it may not be easy for a user with visual handicap to confirm information input by the user. In this case, an expression unit facilitates confirmation of the information. 
     Also, even a user who has not yet mastered characters may easily sense whether an input is correct or incorrect in the course of practicing characters through an expression unit. Here, the expression unit may express a correct answer and an incorrect answer in different pre-set protruding shapes of expression members other than in the form of Braille, thereby facilitating a user to recognize an expression indicating a correct answer or an incorrect answer. 
     Through this, it is possible to easily provide feedbacks on information input by users in various conditions, thereby improving user convenience of confirming and learning information. 
     In addition, it is possible to efficiently perform a continuous input operation and a feedback thereto by controlling the operation of the expression unit, for example, initialization through the operation control unit. 
     Also, since an operation control unit initiates recognition through an input information recognition unit and the operation of an expression unit regarding the recognition only when necessary, the efficiency and power consumption reduction characteristics of an input feedback-based smart pen may be improved. 
       FIG. 11  is a diagram showing an input feedback-based smart pen according to another embodiment of the present disclosure. 
     An input feedback-based smart pen  300  of the present embodiment may include a main body  301 , an input unit  310 , an input information recognition unit  320 , an expression unit  350 , and a speaker  370 . 
     For convenience of explanation, descriptions below will focus on differences from the above-described embodiment. 
     The main body  301  may have a shape that enables manipulation of a user. For example, the main body  301  may have a pillar-like shape to be held by a user, and, as a specific example, may have a cylindrical shape, a prismatic shape, or an elliptical pillar-like shape. 
     When a user manipulates an input feedback main body  301 , the user may hold the main body  301  by a hand, and, in this case, a top end  302  including an uppermost region located over the upper portion of the main body  301 . 
     According to an optional embodiment, the top end  302  may include a region formed to be thinner than the main body  301 , and, although not shown, according to another embodiment, a hook or a handle may be further formed at the top end  302  to improve user convenience. 
     The input unit  310  is connected to the main body  301  and may perform an input operation by a manipulation of a user. The input unit  310  may allow visual expression of forms like characters or drawings on a medium like paper. For example, the input unit  310  may have a shape similar to a portion of a ballpoint pen lead, a pencil lead, or a felt pen. 
     According to an optional embodiment, a result of an input operation of the input unit  310  may not be visually displayed on a medium like paper. For example, when there is an input operation of a user using the input unit  310 , information regarding changes due to the movement of the input unit  310  may be recognized by the input information recognition unit  320  to be described later as a result of the input operation. 
     In this case, the input unit  310  may not need to separately provide a lead like a pencil lead, a ballpoint pen lead, or a felt pen. 
     The input information recognition unit  320  may recognize information input by a user by manipulating the input unit  310 . 
     For example, when a user draws letters and/or drawings or performs various input operations on paper by using the input unit  310 , the input information recognition unit  320  may recognizes visually identifiable information like letters, drawings, or figures drawn on the paper. 
     According to an optional embodiment, the input information recognition unit  320  may include an optical member, e.g., a photographing member. 
     As shown in  FIG. 10 , the input information recognition unit  320  may be formed in one area of the main body  301 . For example, the input information recognition unit  320  may be formed at the bottom end of the main body  301 . 
     According to an optional embodiment, the examples of  FIGS. 2 and 3  may be applied. 
     According to an optional embodiment, the input information recognition unit  320  may include a motion detecting sensor to detect an input by the input unit  310 . For example, when a user moves the input unit  310  to write a character by using the input unit  310 , the movement of the input unit  310  may be detected. According to an optional embodiment, as described above, a result of an input operation using the input unit  310  may not be visually displayed. In this case, the input information recognition unit  320  including the motion detecting sensor may easily detect an input made by using the input unit  310 . 
     According to an optional embodiment, the motion detecting sensor of the input information recognition unit  320  may not be exposed to the outside. For example, the motion detecting sensor may be disposed inside the main body  301 . Alternatively, the input information recognition unit  320  may be formed inside or on one side of the input unit  310  through fine formation. 
     The expression unit  350  may be disposed on an area of the outer surface of the main body  301  to express information corresponding to input information recognized by the input information recognition unit  320 . 
     The expression unit  350  may be formed to be recognizable by a user. For example, the expression unit  350  may be formed in correspondence to a finger of a user. 
     The expression unit  350  may include one or more expression members (not shown) to be recognizable by a user. For example, the expression unit  350  may include a plurality of expression members (not shown). 
     The expression member (not shown) may be formed to be recognizable by a user by moving to protrude toward at least one area of a finger of the user. 
     Although not shown, the structures of  FIGS. 4 and 5  may also be applied to the present embodiment. 
     The expression unit  350  may express content input by a user through the input unit  310 . For example, when a user inputs a character through the input unit  310 , the input information recognition unit  320  may recognize the input in various ways as described above. Recognized information may be expressed by the expression unit  350 , and the user may sense an expression of the expression unit  350 . 
     Therefore, the user may sense information about contents input through the input unit  310 . 
     According to an optional embodiment, when a user is visually handicapped with no vision or very weak eyes, it may not be easy to visually confirm even content that the user inputs through the input unit  310 . According to the present embodiment, in such a case, the expression unit  350  may allow a user to confirm an input by allowing the user to sense information about the input through protrusion of the expression member (not shown). 
     As a specific example, when a user intends to input the character “san (mountain)” through the input unit  310 , the input information recognition unit  320  may recognize content of the input through the input unit  310 , the expression unit  350  may express the content to allow the user to sense an expression thereof, and, even when it is difficult for the user to visually confirm the input made by the user due to visual handicap, the user may confirm the input by sensing protrusion of the expression member (not shown) of the expression unit  350 . The protrusion of the expression member (not shown) may correspond to a type of Braille. For example, when “san (mountain)” is input through the input unit  310 , the expression member (not shown) of the expression unit  350  may have a protruding shape to express “mountain” in Braille. 
     According to an optional embodiment, an information processing unit  330  may be further provided, and the information processing unit  330  may process various information by using information recognized by the input information recognition unit  320  and transmit processed information to the expression unit  350 . 
     For example, the information processing unit  330  may process Braille information regarding an input made by a user. 
     Also, according to another embodiment, the information processing unit  330  may process voice information regarding an input made by a user. 
     According to an optional embodiment, the information processing unit  330  may include a storage unit for storing one or more pieces of Braille data information. 
     According to an optional embodiment, the information processing unit  330  may include a character determiner, a figure determiner, etc. for determining an input made by a user and may include a database for this purpose. 
     Also, as an additional example, the information processing unit  130  may include a text information conversion control unit for converting input information into text information. 
     According to an optional embodiment, when a user inputs a character, the information processing unit  330  may process expression information for a correct answer or an incorrect answer by determining whether the character input by the user is a correct character or not. 
     The expression unit  350  may be implemented in various forms. For example, the plurality of expression members (not shown) of the expression unit  350  may be arranged in correspondence to through holes (not shown) of a base (not shown), respectively, and may be sensed by fingers of a user by protruding out of the through holes (not shown) or receding into the through holes (not shown). 
     Also, although not shown, the structure of  FIG. 6  or  FIG. 7  may be applied as an optional embodiment. 
     The speaker  370  is formed to generate a sound (e.g., a voice) including one or more pieces of information to a user and, for example, may be formed in one area of the top end  302 . 
     For example, after a content is input through the input unit  310 , the input information recognition unit  320  may recognize the content, and the expression unit  350  may express a recognized content through the speaker  370 , wherein the recognized content may be expressed in voice by the expression unit  350 . For example, the expression unit  350  may inform the recognized content to a user by a voice “san (mountain)”. 
     Also, a user may be informed of a set problem through the speaker  370  by voice. As a result of an input operation of the user for the set problem through the input unit  310 , the input information recognition unit  320  may recognize an input content input by the user, and the expression unit  350  or the speaker  370  may feedback the input content input by the user. 
     At this time, the input content may be directly fed back to be sensed (e.g., an expression corresponding to “san (mountain)”) or it may be indirectly fed back by expressing “correct” or “incorrect” based on whether a correct input for the set problem is input, wherein such expressions may be made by pre-set protruding shapes of expression members of the expression unit  350 . 
     Through this, it is possible to expand the operation and usability of the input feedback-based smart pen  300  and increase user convenience. 
     An input feedback-based smart pen of the present embodiment enables a user to hold a main body, thereby facilitating an input operation through an input unit. At this time, as a result of the input operation, an input content may be visually displayed on paper like in the case of using an actual pencil or pen or may not be displayed. An input information recognition unit may recognize such input contents, and an expression unit may express recognized information. According to an optional embodiment, one or more pieces of processed information, e.g., Braille information, information indicating a correct answer or an incorrect answer, etc., may be transmitted to an expression unit based on information recognized by an input information recognition unit and made recognizable by a user through protrusion of one or more expression members of an expression unit. 
     With respect to a content input by a user through an input unit, the user may confirm information input by the user by detecting a protruding shape of expression members of an expression unit immediately or a short time after the input. For example, it may not be easy for a user with visual handicap to confirm information input by the user. In this case, an expression unit facilitates confirmation of the information. 
     Also, even a user who has not yet mastered characters may easily sense whether an input is correct or incorrect in the course of practicing characters through an expression unit. Here, the expression unit may express a correct answer and an incorrect answer in different pre-set protruding shapes of expression members other than in the form of Braille, thereby facilitating a user to recognize an expression indicating a correct answer or an incorrect answer. 
     Through this, it is possible to easily provide feedbacks on information input by users in various conditions, thereby improving user convenience of confirming and learning information. 
     Also, an input feedback-based smart pen may be used for various purposes by notifying a user of various information (e.g., content expressed by an expression unit for information input by the user) by voice through a speaker or by informing the user of a set problem in advance. 
     For example, an input feedback-based smart pen may facilitate character learning of a user. As a specific example, after a problem is given through speaker and the user inputs a character corresponding to the problem, the user may receive a direct feedback indicating whether the input character is correctly input. 
     Therefore, it is possible to increase the convenience of users in the process of learning characters or users having visual handicap. 
       FIG. 12  is a diagram showing an input feedback-based smart pen according to another embodiment of the present disclosure. 
       FIGS. 13 to 17  are diagrams showing examples of use of the input feedback-based smart pen of  FIG. 12 . 
     An input feedback-based smart pen  400  of the present embodiment may include a main body  401 , an input unit  410 , an input information recognition unit  420 , an expression unit  450 , and a speaker  470 . 
     For convenience of explanation, descriptions below will focus on differences from the above-described embodiment. 
     The main body  401  may have a shape that enables manipulation of a user. For example, the main body  401  may have a pillar-like shape to be held by a user, and, as a specific example, may have a cylindrical shape, a prismatic shape, or an elliptical pillar-like shape. 
     When a user manipulates an input feedback main body  401 , the user may hold the main body  401  by a hand, and, in this case, a top end  402  including an uppermost region located over the upper portion of the main body  401 . 
     According to an optional embodiment, the top end  402  may include a region formed to be thinner than the main body  401 , and, although not shown, according to another embodiment, a hook or a handle may be further formed at the top end  402  to improve user convenience. 
     The input unit  410  is connected to the main body  401  and may perform an input operation by a manipulation of a user. The input unit  410  may allow visual expression of forms like characters or drawings on a medium like paper. For example, the input unit  410  may have a shape similar to a portion of a ballpoint pen lead, a pencil lead, or a felt pen. 
     According to an optional embodiment, a result of an input operation of the input unit  410  may not be visually displayed on a medium like paper. For example, when there is an input operation of a user using the input unit  410 , information regarding changes due to the movement of the input unit  410  may be recognized by the input information recognition unit  420  to be described later as a result of the input operation. 
     In this case, the input unit  410  may not need to separately provide a lead like a pencil lead, a ballpoint pen lead, or a felt pen. 
     The input information recognition unit  420  may recognize information input by a user by manipulating the input unit  410 . 
     For example, when the user inputs a character or a drawing or performs other various input operations on paper using the input unit  410 , the input information recognition unit  420  recognizes visually verifiable information such as characters, pictures, or figures written on the paper. 
     According to an optional embodiment, the input information recognition unit  420  may include an optical member, e.g., a photographing member. 
     As shown in  FIG. 12 , the input information recognition unit  420  may be formed in one area of the main body  401 . For example, the input information recognition unit  420  may be formed at the bottom end of the main body  401 . 
     According to an optional embodiment, the examples of  FIGS. 2 and 3  may be applied. 
     According to an optional embodiment, the input information recognition unit  420  may include a motion detecting sensor to detect an input by the input unit  410 . For example, when a user moves the input unit  410  to write a character by using the input unit  410 , the movement of the input unit  410  may be detected. According to an optional embodiment, as described above, a result of an input operation using the input unit  410  may not be visually displayed. In this case, the input information recognition unit  420  including the motion detecting sensor may easily detect an input made by using the input unit  410 . 
     According to an optional embodiment, the motion detecting sensor of the input information recognition unit  420  may not be exposed to the outside. For example, the motion detecting sensor may be disposed inside the main body  401 . Alternatively, the input information recognition unit  420  may be formed inside or on one side of the input unit  410  through fine formation. 
     The expression unit  450  may be disposed on an area of the outer surface of the main body  401  to express information corresponding to input information recognized by the input information recognition unit  420 . 
     The expression unit  450  may be formed to be recognizable by a user. For example, the expression unit  450  may be formed in correspondence to a finger of a user. 
     The expression unit  450  may include one or more expression members (not shown) to be recognizable by a user. For example, the expression unit  450  may include a plurality of expression members (not shown). 
     The expression member (not shown) may be formed to be recognizable by a user by moving to protrude toward at least one area of a finger of the user. 
     Although not shown, the structures of  FIGS. 4 and 5  may also be applied to the present embodiment. 
     The expression unit  450  may express content input by a user through the input unit  410 . For example, when a user inputs a character through the input unit  410 , the input information recognition unit  420  may recognize the input in various ways as described above. Recognized information may be expressed by the expression unit  450 , and the user may sense an expression of the expression unit  450 . 
     Therefore, the user may sense information about contents input through the input unit  410 . 
     According to an optional embodiment, when a user is visually handicapped with no vision or very weak eyes, it may not be easy to visually confirm even content that the user inputs through the input unit  410 . According to the present embodiment, in such a case, the expression unit  450  may allow a user to confirm an input by allowing the user to sense information about the input through protrusion of the expression member (not shown). 
     As a specific example, when a user intends to input the character “san (mountain)” through the input unit  410 , the input information recognition unit  420  may recognize content of the input through the input unit  410 , the expression unit  450  may express the content to allow the user to sense an expression thereof, and, even when it is difficult for the user to visually confirm the input made by the user due to visual handicap, the user may confirm the input by sensing protrusion of the expression member (not shown) of the expression unit  450 . The protrusion of the expression member (not shown) may correspond to a type of Braille. For example, when “san (mountain)” is input through the input unit  410 , the expression member (not shown) of the expression unit  450  may have a protruding shape to express “mountain” in Braille. 
     According to an optional embodiment, an information control unit  430  may be further provided, and the information control unit  430  may process various information by using information recognized by the input information recognition unit  420  and transmit processed information to the expression unit  450 . 
     For example, the information control unit  430  may process Braille information regarding an input made by a user. 
     Also, according to another embodiment, the information control unit  430  may process voice information regarding an input made by a user. 
     According to an optional embodiment, the information control unit  430  may include a storage unit for storing one or more pieces of Braille data information. 
     According to an optional embodiment, the information control unit  430  may include a character determiner, a figure determiner, etc. for determining an input made by a user and may include a database for this purpose. 
     Also, as an additional example, the information processing unit  130  may include a text information conversion control unit for converting input information into text information. 
     According to an optional embodiment, when a user inputs a character, the information control unit  430  may process expression information for a correct answer or an incorrect answer by determining whether the character input by the user is a correct character or not. 
     The expression unit  450  may be implemented in various forms. For example, the plurality of expression members (not shown) of the expression unit  450  may be arranged in correspondence to through holes (not shown) of a base (not shown), respectively, and may be sensed by fingers of a user by protruding out of the through holes (not shown) or receding into the through holes (not shown). 
     Also, the information control unit  430  may generate and handle a set problem. For example, a user may be asked to input a content for a set problem, and more specifically, a specific character, and such a set problem may be presented to the user through the expression unit  450  or through the speaker  470  according to an optional embodiment to be described later. 
     To this end, the information control unit  430  may include a storage unit including one or more characters, words, etc. or may be connected to such a storage unit. Also, according to an optional embodiment, the information control unit  430  may be connected to the storage unit wirelessly, and, as occasions demand, the information control unit  430  may receive information through data connection and communication using the web. 
     According to an optional embodiment, a wireless communication module connected to the information control unit  430  or a separate wireless communication module may be provided, and information about the a user&#39;s operation may be transmitted to an external device, such as a smartphone, through the wireless communication module. 
     According to an optional embodiment, an input feedback-based smart pen according to the present embodiment or the previous embodiment may be connected to an external terminal, e.g., a user&#39;s smartphone, for communication and output a content to be output from an expression unit to the smartphone. 
     Also, one or more pieces of information of the smartphone may be transmitted to the expression unit, such that the user may sense the information. 
     Also, although not shown, the structure of  FIG. 6  or  FIG. 7  may be applied as an optional embodiment. 
     The speaker  470  is formed to generate a sound (e.g., a voice) including one or more pieces of information to a user and, for example, may be formed in one area of the top end  402 . 
     For example, after a content is input through the input unit  410 , the input information recognition unit  420  may recognize the content, and the expression unit  450  may express a recognized content through the speaker  470 , wherein the recognized content may be expressed in voice by the expression unit  450 . For example, the expression unit  450  may inform the recognized content to a user by a voice “san (mountain)”. 
     Also, as described above, when the information control unit  430  generates a set problem, a user may be informed of the set problem through the speaker  470  by voice. As a result of an input operation of the user for the set problem through the input unit  410 , the input information recognition unit  420  may recognize an input content input by the user, and the expression unit  450  or the speaker  470  may feedback the input content input by the user. 
     At this time, it is possible to detect the content directly fed back, for example, “mountain”, or mark it as “correct” or “wrong” by distinguishing whether the input for the set problem was indirectly correct or not. In this regard, it may be informed in the form of protrusions of the expression members of the expression unit  450  set in advance. 
     Therefore, the operation and the usability of the input feedback-based smart pen  400  may be expanded and user convenience may be improved. 
     Detailed descriptions thereof will be given with reference to  FIGS. 13 to 17 . 
     Referring to  FIG. 13 , the contents of the setting problem PB are displayed. For example, a set problem PB is a character “san (mountain)”. This set problem PB may be generated by the information control unit  430  and may be output as voice through the speaker  470 , such that a user may recognize it. 
     Also, according to an optional embodiment, the set problem PB may be recognized by a user through the protruding shape of the expression members of the expression unit  450 , e.g., a Braille. 
     The user may sense such a set problem and input a content corresponding to the set problem. For example, as shown in  FIG. 14 , a content corresponding to a set problem may be input by manipulating the input feedback-based smart pen  400  by a hand. 
     Here, when the content input by the user through the input unit  410  matches with the set problem PB (for example, when the character “san (mountain)” is accurately written), the expression unit  450  may express the content, that is, “san (mountain)”. The expression may be in the form of Braille form or may be in the form of other symbols. According to an optional embodiment, a voice “san (mountain)” may be output through the speaker  470 . 
     Also, according to an optional embodiment, information indicating that an input content matches with a set problem may be output. For example, matching information YI may be expressed as shown in  FIG. 15 . For example, the word “correct answer” may be expressed through the expression unit  450  or a voice “correct answer” may be output through the speaker  470 . 
     On the other hand, a content input by a user may not match with a set problem. 
     For example, as shown in  FIG. 16 , a content corresponding to the set problem PB may be input by manipulating the input feedback-based smart pen  400  by a hand and, when the input content does not match with the set problem PB (for example, when the character “san (mountain)” is incorrectly written and may not be read as “san”), the expression unit  450  may express that the input content is not recognizable or does not match with the set problem PB and, as a specific example, may express “not acceptable”. The expression may be in the form of Braille form or may be in the form of other symbols. According to an optional embodiment, a voice “not acceptable” may be output through the speaker  470 . 
     Also, according to an optional embodiment, information indicating that an input content does not match with a set problem may be output. For example, non-matching information NI may be expressed as shown in  FIG. 17 . For example, the word “incorrect answer” may be expressed through the expression unit  450  or a voice “incorrect answer” may be output through the speaker  470 . 
     An input feedback-based smart pen of the present embodiment enables a user to hold a main body, thereby facilitating an input operation through an input unit. At this time, as a result of the input operation, an input content may be visually displayed on paper like in the case of using an actual pencil or pen or may not be displayed. An input information recognition unit may recognize such input contents, and an expression unit may express recognized information. According to an optional embodiment, one or more pieces of processed information, e.g., Braille information, information indicating a correct answer or an incorrect answer, etc., may be transmitted to an expression unit based on information recognized by an input information recognition unit and made recognizable by a user through protrusion of one or more expression members of an expression unit. 
     With respect to a content input by a user through an input unit, the user may confirm information input by the user by detecting a protruding shape of expression members of an expression unit immediately or a short time after the input. For example, it may not be easy for a user with visual handicap to confirm information input by the user. In this case, an expression unit facilitates confirmation of the information. 
     Also, even a user who has not yet mastered characters may easily sense whether an input is correct or incorrect in the course of practicing characters through an expression unit. Here, the expression unit may express a correct answer and an incorrect answer in different pre-set protruding shapes of expression members other than in the form of Braille, thereby facilitating a user to recognize an expression indicating a correct answer or an incorrect answer. 
     Through this, it is possible to easily provide feedbacks on information input by users in various conditions, thereby improving user convenience of confirming and learning information. 
     In addition, it is possible to easily receive feedback on the content entered by the user by generating and presenting a setting problem to the user, and expressing whether the user responds to the input as a correct or incorrect answer. 
     Therefore, the input feedback-based smart pen may facilitate character learning of a user. As a specific example, convenience of users in the process of learning characters or users having visual handicap may be improved. 
       FIG. 18  is a diagram schematically showing a protruding feedback-based smart tablet according to an embodiment of the present disclosure, and  FIGS. 19 and 20  are diagrams showing an input pen shown in  FIG. 18 . 
       FIGS. 21 and 22  are diagrams for describing the operation of the protruding feedback-based smart tablet of  FIG. 18 . 
     Referring to  FIG. 18 , a protruding feedback-based smart tablet  600  of the present embodiment may include an expression area DA. 
     A plurality of output units (described later in  FIG. 21  and the like) are formed in the expression area DA. 
     A user may make various inputs to the expression area DA by using an input pen  500 . For example, a user may write characters, draw figures, and make inputs in various other forms. 
     A plurality of output units may protrude in the expression area DA according to a shape input by the user using the input pen  500 , and a shape input by the user by using the input pen  500  (e.g., a character or a figure) may be output through a protruding shape. As a specific example, the user may visually or tactilely sense an output shape. 
     According to an embodiment, when a user inputs one character or a character string in the expression area DA by using the input pen  500 , a plurality of output units may protrude in response to the input, and, after the user puts down the input pen  500 , the user may confirm the character or the character string input by the user by tactilely sensing a protruding shape of the output units through a finger or a palm. The protruding shape may also be visually confirmed. 
     Therefore, after a user having visual handicap inputs a character by using the input pen  500 , the user may tactilely sense the character written by the user through the protruding shape of a plurality of output units and check whether the character is correctly written by the user. 
     The input pen  500  may have various shapes. 
     Referring to  FIG. 19 , the input pen  500  may include a magnetic body  510 . For example, the magnetic body  510  may be accommodated in the input pen  500 , and the magnetic body  510  may include a permanent magnet. 
     Also, according to another embodiment, when a permanent magnet is included in an output unit to be described later, the magnetic body  510  may include, for example, iron, nickel, or a stainless steel-based alloy material. 
     According to an optional embodiment, the magnetic body  510  may be disposed to face an end of the input pen  500 , and, for example, may be disposed to be located close to a lower end, that is, the expression area DA of the protruding feedback-based smart tablet  600 , when the user holds the input pen  500  in his hand and makes an input. 
     Also, according to an optional embodiment, when the magnetic body  510  includes a permanent magnet, the permanent magnet may be disposed, such that one pole (e.g., an N pole or an S pole) faces an end of the input pen  500 . 
     Through the movement of the input pen  500  including the magnetic body  510 , the output units of the expression area DA of the protruding feedback-based smart tablet  600  may protrude by a magnetic field due to the magnetic body  510 . Detailed descriptions thereof will be given later. 
       FIG. 20  is a modified example of  FIG. 19 , wherein an input pen  500 ′ includes a magnetic body  510 ′, and the magnetic body  510 ′ may be disposed in a shape protruding to the outside. For example, at least one area of the magnetic body  510 ′ may be disposed outside the input pen  500 ′, and, as a specific example, may be exposed at the lower end of the input pen  500 ′. 
     Also, according to an optional embodiment, the magnetic body  510 ′ may be connected or attached to the lower end of the input pen  500 ′. 
       FIGS. 21 and 22  are diagrams for describing the operation of the protruding feedback-based smart tablet of  FIG. 18 . 
       FIG. 21  is an enlarged view of an area of the expression area DA of the protruding feedback-based smart tablet  600  including a plurality of output units. For example, in  FIG. 21 , nine output units IU 1  to IU 9  are shown. However, it is for merely convenience of explanation, and the number of output units included in the expression area DA of the protruding feedback-based smart tablet  600  may vary in consideration of the size of the expression area DA, the resolution of an output shape, etc. 
     Referring to  FIG. 21 , all of the plurality of output units IU 1  to IU 9  of the protruding feedback-based smart tablet  600  have non-protruding shapes. For example, all of the output units IU 1  to IU 9  have shapes which do not protrude through an expression penetration portion  602   a  formed in a cover portion  602 . 
     A user may hold the input pen  500  and makes an input by freely moving the input pen  500 . For example, the user may draw a character, a figure, or a drawing. 
     For example, as shown in  FIG. 21 , a line shape may be input by moving the input pen  500  in a direction D 1 . As a specific example, the input may correspond to drawing a line on paper with a pen. 
       FIG. 22  shows that output units IU 4 , IU 5 , and IU 6  from among the plurality of output units IU 1  to IU 9  protrude according to a user&#39;s input through the input pen  500 . 
     For example, when the input pen  500  is moved on the expression area DA, and more specifically, on the expression area DA while in contact with at least one area of the expression area DA to draw a line, output units IU 4 , IU 5 , and IU 6  corresponding to a moved path may protrude. 
     As described above, the output units IU 4 , IU 5 , and IU 6  adjacent to the magnetic body  510  of the input pen  500  may be protruded by a magnetic field due to the magnetic body  510  of the input pen  500 . 
     According to an optional embodiment, the output units IU 4 , IU 5 , and IU 6  having a protruding shape may maintain the shape for a certain period of time. Therefore, a user may check a shape input by the user, e.g., the shape of a line, and, as a specific example, even a user having visual handicap may tactilely sense the shape of a line input by the user. 
     Also, by using a reset member (not shown), the output units IU 4 , IU 5 , and IU 6  in a protruding state may be reset to their original state, that is, a non-protruding state. Such a reset member (not shown) may be disposed inside or on one surface of the protruding feedback-based smart tablet  600 . According to another embodiment, the reset member (not shown) may be separately provided. 
     Also, according to an optional embodiment, a reset member (not shown) may be provided at the input pen  500 . 
     Detailed descriptions of such a reset member (not shown) will be given later. 
     The output units IU 1  to IU 9  will be described below in detail. For convenience of explanation, one output unit will be described. 
       FIG. 23  is a cross-sectional view taken along a line VI-VI of  FIG. 21 , and  FIG. 24  is an exploded perspective view of one output unit of  FIG. 21  illustrated for convenience of explanation. 
     An output unit IU 8  may include an expression unit  610 , a moving unit  630 , a magnetic unit  640 , and a base unit  660 . 
     According to an optional embodiment, the output unit IU 8  of the present embodiment may further include an expression unit insert  620 . 
     According to an optional embodiment, the output unit IU 8  may further include a base unit insert  670 . 
     Each member will be described in detail with reference to the attached drawings. 
       FIG. 25  is a schematic perspective view of an expression unit of an output unit of  FIG. 23 ,  FIG. 26  is a schematic front view of the expression unit of the output unit of  FIG. 23 ,  FIG. 27  is a perspective view of the expression unit of the output unit of  FIG. 23  taken in a direction from that of  FIG. 25 , and  FIG. 28  is a schematic bottom view of the expression unit of the output unit of  FIG. 23 . 
     The expression unit  610  may move according to the movement of the moving unit  630  to be described later and may move upward and downward at least in the lengthwise direction of the expression unit  610 . Therefore, the expression unit  610  may be moved to protrude in one direction, and a user may sense the movement of the expression unit  610  tactilely or visually. 
     The expression unit  610  may include a body member  611 , an expression member  613 , and transmission members  615  and  616 . 
     The body member  611  may constitute a lower portion of the expression unit  610  and support the expression member  613 . Also, the body member  611  to be described later may be moved by a force transmitted through transmission members  615  and  616  and may also transmit the force to the expression member  613 , such that the expression member  613  may be moved. 
     According to an optional embodiment, the body member  611  may have a pillar-like shape having a certain height and a certain width, may have a curved outer circumferential surface, and may include, for example, at least one area of a side surface of a cylinder. 
     The expression member  613  may be connected to the body member  611  and be moved by the body member  611 . For example, the expression member  613  may move simultaneously with the body member  611 . The expression member  613  may have a shape protruding in one direction. For example, the expression member  613  may have a pillar-like area and a protruding area connected thereto. 
     In this case, the protruding area of the expression member  613  may have a curved surface and may also have rounded corners. 
     The expression member  613  may include various materials and may include an insulating material as a light and durable material. For example, the expression member  613  may include a resin-based organic material. According to another embodiment, the expression member  6   t   3  may include an inorganic material, such as a ceramic material. 
     Also, according to another selective embodiment, the expression member  613  may include a material like a metal or glass. 
     According to an optional embodiment, a connection area  619  may be formed between the body member  611  and the expression member  613 . 
     The connection area  619  has a width smaller than those of the body member  611  and the expression member  613 , such that a separation space  618  is formed in a corresponding area adjacent to the connection area  619  and between the body member  611  and the expression member  613 . 
     The transmission members  615  and  616  may have a shape extending from the body member  611  and have a shape protruding downward more than the body member  611 . Therefore, the transmission members  615  and  616  may be located closer to the moving unit  630  than the body member  611 . 
     According to an optional embodiment, a plurality of transmission members  615  and  616  may be provided. In other words, the transmission members  615  and  616  may include a first transmission member  615  and a second transmission member  616 . 
     The first transmission member  615  may have various shapes. For example, the first transmission member  615  may have a shape that protrudes to pass the bottommost surface of the body member  611  in the lengthwise direction of the expression unit  610 . In other words, the first transmission member  615  may have a shape elongated to pass through a surface of the body member  611  opposite an area facing the expression member  613  from among areas of the body member  611 . 
     The first transmission member  615  may have a shape protruding from a side surface of the body member  611 . Therefore, the side surface of the first transmission member  615  and the side surface of the body member  611  may form a curved shape without being coplanar with each other. 
     According to an optional embodiment, the first transmission member  615  may include a slide surface  615 A at an end thereof. For example, the slide surface  615 A may have a shape inclined in one direction. 
     The first transmission member  615  may correspond to guide grooves  663  and  664  of the base unit  660 , and the slide surface  615 A may correspond to an engaging sliding area  665  and a connecting sliding area  666 . Detailed descriptions thereof will be given later. 
     The second transmission member  616  may have various shapes. For example, the second transmission member  616  may have a shape that protrudes to pass the bottommost surface of the body member  611  in the lengthwise direction of the expression unit  610 . In other words, the second transmission member  616  may have a shape elongated to pass through a surface of the body member  611  opposite an area facing the expression member  613  from among areas of the body member  611 . 
     The second transmission member  616  may have a shape protruding from a side surface of the body member  611 . Therefore, the side surface of the second transmission member  616  and the side surface of the body member  611  may form a curved shape without being coplanar with each other. 
     According to an optional embodiment, the second transmission member  616  may include a slide surface  616 A at an end thereof. For example, the slide surface  616 A may have a shape inclined in one direction. 
     The second transmission member  616  may correspond to the guide grooves  663  and  664  of the base unit  660 , and the slide surface  616 A may correspond to the engaging sliding area  665  and the connecting sliding area  666 . Detailed descriptions thereof will be given later. 
     The first transmission member  615  and the second transmission member  616  may be arranged at various locations. For example, the first transmission member  615  and the second transmission member  616  may be formed in correspondence to a first guide groove  663  and a second guide groove  664  of the base unit  660  to be described later. 
     According to an optional embodiment, the first transmission member  615  and the second transmission member  616  may have a symmetrical shape around the center of the expression unit  610 . 
     For example, a distance from the first transmission member  615  to the second transmission member  616  in the clockwise direction may be the same as a distance therebetween in the counterclockwise direction. 
     According to another embodiment, when the body member  611  is rotated 180 degrees around a rotation axis, the first transmission member  615  and the second transmission member  616  may switch positions with each other, and, when the body member  611  is rotated 360 degrees, the first transmission member  615  and the second transmission member  616  may return to their original locations. 
     According to another selective embodiment, the expression unit  610  may include three, four, or more transmission members (not shown). In this case, that is, when the expression unit  610  includes three transmission members, when the expression unit  610  is rotated 120 degrees, the transmission members may each be moved to the location of an adjacent transmission member, When the expression unit  610  includes four transmission members, when the expression unit  610  is rotated 90 degrees, the transmission members may each be moved to the location of an adjacent transmission member, 
     According to an optional embodiment, a direction in which the slide surface  615 A of the first transmission member  615  is inclined may be the same as the direction in which the slide surface  616 A of the second transmission member  616  is inclined. 
     For example, when the expression unit  610  is rotated about the rotation axis, the slide surface  615 A of the first transmission member  615  and the slide surface  616 A of the second transmission member  616  may be inclined in a direction in which the expression unit  610  is rotated. 
     According to an optional embodiment, the output unit IU 8  may further include the expression unit insert  620 . 
       FIG. 29  is a front view of an expression unit and an expression unit insert. 
     Referring to  FIG. 29 , the expression unit insert  620  may be disposed adjacent to the expression unit  610 , and, according to an optional embodiment, may be disposed between the expression member  613  and the body member  611 . 
     Also, as a specific example, the expression unit insert  620  may be disposed to surround the connection area  619  and correspond to the separation space  618 . 
     The expression unit insert  620  may have a width greater than that of the expression member  613 . For example, the expression unit insert  620  may be formed to have a wider area than the expression member  613 . 
     According to an optional embodiment, the expression unit insert  620  may be formed to have a more protruding shape than the expression member  613 , the body member  611 , and the transmission members  615  and  616 , thereby restricting the descending of the expression unit  610 , that is, the movement of the expression unit  610  in a direction toward the bottom surface of the base unit  660 . 
     The expression unit insert  620  may include various materials. 
     According to an optional embodiment, the expression unit insert  620  may include a magnetic material, e.g., iron, nickel, or a stainless steel-based alloy material. 
     The expression unit insert  620  may be manufactured in various ways. When the expression unit  610  is manufactured, the expression unit  610  in which the expression unit insert  620  is disposed may be easily manufactured through injection molding. 
     When the expression unit insert  620  includes a magnetic material, the expression unit insert  620  may interact with the magnetic unit  640  during the movement of the moving unit  630 , which will be described later. For example, when the expression unit  610  and the moving unit  630  are moved upward, the expression unit  610  and the moving unit  630  are attracted by the magnetic field between the expression unit insert  620  and the magnetic unit  640 , and thus the moving unit  630  may maintain its position while facing toward the expression unit  610 . Alternatively, the moving unit  630  may still be prevented from rapidly descending. 
     Also, since the expression unit  610  may be disposed while maintaining a state of being fixed to face the moving unit  630 , it is possible to facilitate stable movement of the expression unit  610 . 
     In addition, when the expression unit insert  620  includes a magnetic material and the moving unit  630  to be described later moves, the efficiency of the movement of the moving unit  630  may be improved due to the influence of the magnetic unit  640 . 
       FIGS. 30 and 31  are front views of other modified examples of the expression unit of the output unit of  FIG. 23 . 
     The output unit IU 8  of the present embodiment may include an expression unit  610 ′ in which the expression unit insert  620  is not provided as shown in  FIG. 30 . 
     The expression unit  610 ′ may include an expression member  613 ′ and a body member  611 ′, may have a shape that the expression member  613 ′ and the body member  611 ′ are elongated, and a connection area may be omitted. Also, a separation space may be omitted. 
     Also, as another modification example,  FIG. 31  shows an expression unit  610 ″ without the expression unit insert  620 , wherein the expression unit  610 ″ may include an expression member  613 ″ and a body member  611 ″, and a protruding portion  6130 ″ may be formed on the side surface of the expression member  613 ″. The protruding portion  6130 ″ may serve as a stopper that limits the movement of the expression unit  610 ″. 
       FIG. 32  is a schematic perspective view of a moving unit of the output unit of  FIG. 23 ,  FIG. 33  is a schematic plan view of the moving unit of the output unit of  FIG. 23 , and  FIG. 34  is a perspective view of the moving unit of the output unit of  FIG. 23 , taken in a direction different from that of  FIG. 32 . 
     The moving unit  630  may be formed to have at least an accommodation space  631 . For example, the moving unit  630  may have a shape in which the accommodation space  631  is provided inside a main area  632 . 
     Also, the magnetic unit  640  may be disposed in the accommodation space  631 . The magnetic unit  640  includes a material having a magnetic force and may be formed to react with the magnetic body  510  of the above-stated input pen  500 . 
     For example, the magnetic unit  640  may include a permanent magnet, such that an attractive force is applied as the magnetic unit  640  is in the proximity of the magnetic body  510  of the input pen  500 . 
     According to an optional embodiment, when the magnetic body  510  of the input pen  500  includes a permanent magnet as described above, the magnetic unit  640  may include a permanent magnet, or, according to another selective embodiment, iron, nickel, or a stainless steel-based alloy material. 
     The magnetic unit  640  may be moved by a reaction with the magnetic body  510  of the input pen  500 , that is, by magnetic fields of the magnetic unit  640  and the magnetic body  510 , and the moving unit  630  may move together with the magnetic unit  640 . 
     To facilitate the movement of the moving unit  630 , the magnetic unit  640  and the moving unit  630  may be fixed. The accommodation space  631  of the moving unit  630  and the magnetic unit  640  may be in close contact with each other, and, according to another embodiment, the accommodation space  631  of the moving unit  630  and the magnetic unit  640  may be bonded to each other. 
     The moving unit  630  may make the expression unit  610  to move. For example, the moving unit  630  may push up the moving unit  630  while supporting the expression unit  610 . 
     The moving unit  630  may include a plurality of support members  635 ,  636 ,  637 , and  638 . 
     For example, the moving unit  630  may include a first support member  635 , a second support member  636 , a third support member  637 , and a fourth support member  638 . 
     The plurality of support members  635 ,  236 ,  237 , and  238  may have a shape protruding in the lengthwise direction of the moving unit  630 . For example, the plurality of support members  635 ,  236 ,  237 , and  238  may have a shape protruding in a direction toward the expression unit  610 . Therefore, the plurality of support members  635 ,  636 ,  637 , and  638  may move the expression unit  610  while supporting the expression unit  610  during the movement of the moving unit  630 . For example, the plurality of support members  635 ,  636 ,  637 , and  638  may push up the expression unit  610 . 
     According to an optional embodiment, the plurality of support members  635 ,  636 ,  637 , and  638  may transmit force to the transmission members  615  and  616  while supporting the transmission members  615  and  616  of the expression unit  610 , such that the expression unit  610  may be moved. 
     According to an optional embodiment, two support members of the plurality of support members  635 ,  636 ,  637 , and  638 , e.g., the first support member  635  and the second support member  636 , may respectively correspond to the transmission members  615  and  616  of the expression unit  610  and transmit force thereto, and, as the expression unit  610  moves, the third support member  637  and the fourth support member  638  may sequentially correspond to the transmission members  615  and  616  of the expression unit  610  and transmit force thereto. 
     According to an optional embodiment, the moving unit  630  may include one or more guides  633  and  634 . For example, the moving unit  630  may include a plurality of guides, that is, a first guide  633  and a second guide  634 . 
     The guides  633  and  634  may have a shape protruding laterally from the main area  632  of the moving unit  630 , and, for example, may have a shape protrude from the main area  632  in a direction away from the accommodation space  631 . 
     The first guide  633  and the second guide  634  may correspond to the first guide groove  663  and the second guide groove  664  of the base unit  660  to be described later, respectively. 
     The first guide  633  and the second guide  634  may have an elongated shape in correspondence to the first guide groove  663  and the second guide groove  664  and may be formed to not to be elongated past the plurality of support members  635 ,  636 ,  637 , and  638 . 
     The moving unit  630  may move while the first guide  633  and the second guide  634  are corresponding to the first guide groove  663  and the second guide groove  664  of the base unit  660 , respectively, thereby controlling rotation or lateral movement of the moving unit  630 . 
     Also, the precise movement of the expression unit  610  may be controlled through the constant movement of the moving unit  630 . 
     According to an optional embodiment, the moving unit  630  may have a through portion  639 . The through portion  639  may be formed to be connected to the accommodation space  631  and may be formed to face the base unit  660 . In other words, when the magnetic unit  640  is disposed in the accommodation space  631 , an area of one surface of the magnetic unit  640  may be exposed through the through portion  639 . 
     The through portion  639  forms a space between the moving unit  630  and the base unit  660  when the moving unit  630  moves, and thus a resistance against the movement of the moving unit  630  due to an airflow formed between the moving unit  630  and the base unit  660  when the moving unit  630  moves up and down may be reduced. 
     Also, the through portion  639  may provide a space for applying pressure to remove the magnetic unit  640  when the magnetic unit  640  needs to be replaced or repaired. 
       FIG. 35  is a schematic perspective view of a base unit of the output unit of  FIG. 23 ,  FIG. 36  is a schematic plan view of the base unit of the output unit of  FIG. 23 , and  FIG. 37  is a perspective view of the base unit of the output unit of  FIG. 23 , taken in a direction different from that of  FIG. 35 . 
     The base unit  660  may include a base space  661 H. In other words, the base space  661 H may be provided as a hollow space inside a body area  661 . The moving unit  630  and the magnetic unit  640  as described above may be arranged in the base space  661 H. Also, one area of the expression unit  610  may be disposed in the base space  661 H according to the movement of the expression unit  610 . 
     According to an optional embodiment, the base unit  660  may have a bottom area  668 . The bottom area  668  may be formed to support the body area  661 . For example, the bottom area  668  may be formed to have a width greater than that of the body area  661 . As a more specific example, the bottom area  668  may have a larger area than the body area  661  and may be formed to surround the body area  661 . 
     According to an optional embodiment, the base unit  660  may have an elongated shape. In this case, the base unit  660  may be formed in correspondence to a plurality of output units provided in the protruding feedback-based smart tablet  600 . 
     According to an embodiment, the base unit  660  may be formed as a single body in correspondence to a plurality of output units. According to another embodiment, the base unit  660  may be formed independently for each output unit. 
     The base unit  660  may include one or more guide grooves  663  and  664 . For example, the guide grooves  663  and  664  may include the first guide groove  663  and the second guide groove  664 . 
     The guide grooves  663  and  664  may have a groove shape formed by removing a predetermined thickness from the base space  661 H of the base unit  660 . 
     As described above, the guide grooves  663  and  664  may correspond to the guides  633  and  634  of the moving unit  630 , respectively. To this end, at least the width of the guide grooves  663  and  664  may be equal to or greater than the width of the guides  633  and  634 . 
     The guide grooves  663  and  664  may have a shape elongated in the lengthwise direction of the base unit  660 . In detail, the guide grooves  663  and  664  may be formed to reach ends of an inlet of the base space  661 H of the base unit  660 . 
     According to an optional embodiment, the base unit  660  may include the engaging sliding area  665  and the connecting sliding area  666 . 
     The engaging sliding area  665  may have a shape formed by removing a predetermined thickness from the base space  661 H and may be formed to be connected to one side of each of the guide grooves  663  and  664 . In other words, one engaging sliding area  665  may be formed to be connected to a side surface of the first guide groove  663  in a first direction, and another engaging sliding area  665  may be formed to be connected to a side surface of the second guide groove  664  in the first direction. 
     The engaging sliding area  665  may be an area in which each of the first transmission member  615  and the second transmission member  616  of the expression unit  610  moves (that is, slides). In other words, when the first transmission member  615  and the second transmission member  616  move past the first guide groove  663  and the second guide groove  664  through the ascending movement of the expression unit  610 , the first transmission member  615  and the second transmission member  616  may naturally move (e.g., slide) to the engaging sliding area  665 , and thus the expression unit  610  may descend by a certain height. 
     According to an optional embodiment, the engaging sliding area  665  may have a sloped surface, wherein, when the slide surface  615 A of the first transmission member  615  and the slide surface  616 A of the second transmission member  616  have sloped surfaces, the sloped surface of the engaging sliding area  665  may be inclined in the same direction as the slide surface  615 A of the first transmission member  615  and the slide surface  616 A of the second transmission member  616 . 
     In addition, an engaging portion  665 A is formed at each end of the engaging sliding area  665 , and thus the first transmission member  615  and the second transmission member  616  may be caught and stopped by engaging portions  665 A without continuing the movements thereof. In other words, the expression unit  610  does not continuously descend and may maintain a stationary state even without support of the moving unit  630 . 
     The connecting sliding area  666  may have a shape formed by removing a predetermined thickness from the base space  661 H and may be formed to be connected to engaging sliding areas  665 , e.g., engaging portions of the engaging sliding areas  665 . Also, the connecting sliding area  666  may be formed to be connected to one side of each of the guide grooves  663  and  664 . 
     In other words, one side of one connecting sliding area  666  may be connected to the engaging portion  665 A of one engaging sliding area  665 , and the other side of the one connecting sliding area  666  may be connected to a side surface of the first guide groove  663  in a second direction. 
     One side of the other one connecting sliding area  666  may be connected to the engaging portion  665 A of one engaging sliding area  665 , and the other side of the other one connecting sliding area  666  may be connected to a side surface of the second guide groove  664  in the second direction. 
     The connecting sliding area  666  may be an area in which each of the first transmission member  615  and the second transmission member  616  of the expression unit  610  moves (that is, slides). 
     In other words, as described above, when the first transmission member  615  and the second transmission member  616  move past the first guide groove  663  and the second guide groove  664  through the ascending movement of the expression unit  610 , the first transmission member  615  and the second transmission member  616  may naturally move (e.g., slide) to the engaging sliding area  665  and ends thereof may be caught by the engaging portions  665 A, thereby maintaining a stationary state. 
     Then, when the first transmission member  615  and the second transmission member  616  move past the engaging portions  665 A through the ascending movement of the expression unit  610  by the moving unit  630 , the first transmission member  615  and the second transmission member  616  may move (e.g., slide) to the connecting sliding area  666 . 
     Also, the connecting sliding area  666  is connected to the first guide groove  663  and the second guide groove  664 , and thus, after the first transmission member  615  and the second transmission member  616  move in the connecting sliding area  666 , the first transmission member  615  and the second transmission member  616  may move from the first guide groove  663  to the second guide groove  664  and may descend toward the moving unit  630  without being supported by the moving unit  630 . 
     According to an optional embodiment, the connecting sliding area  666  may have a sloped surface, wherein, when the slide surface  615 A of the first transmission member  615  and the slide surface  616 A of the second transmission member  616  have sloped surfaces, the sloped surface of the connecting sliding area  666  may be inclined in the same direction as the slide surface  615 A of the first transmission member  615  and the slide surface  616 A of the second transmission member  616 . 
     Also, the direction in which the connecting sliding area  666  is inclined may be the same as the direction in which the engaging sliding area  665  is inclined. 
     According to an optional embodiment, the base unit insert  670  may be further included in an area inside the base unit  660 . 
     As a specific example, the base unit insert  670  may be disposed in an insertion space  669  inside the bottom area  668  of the base unit  660 . The base unit insert  670  may be disposed to be connected to the base space  661 H as shown in  FIG. 36 . 
     The base unit insert  670  may include various materials. 
     According to an optional embodiment, the base unit insert  670  may include a magnetic material, e.g., iron, nickel, or a stainless steel-based alloy material. 
     The base unit insert  670  may be manufactured in various ways. When the base unit  660  is manufactured, the base unit  660  in which the base unit insert  670  is disposed may be easily manufactured through injection molding. 
     When the base insert  670  includes a magnetic material, attractive force is applied between the base unit insert  670  and the moving unit  630  by the magnetic field between the base unit insert  670  and the magnetic unit  640 , thereby facilitating the movement of the moving unit  630  during the descending movement of the moving unit  630 . 
     Also, when the moving unit  630  maintains a descended state, the moving unit  630  may stably maintain its position by the magnetic field between the magnetic unit  640  and the base unit insert  670 . 
     When the base unit insert  670  includes a magnetic material and the moving unit  630  to be described later moves, the efficiency of the movement of the moving unit  630  may be improved due to the influence of the magnetic unit  640 . 
       FIGS. 38A to 38E  are diagrams for describing an example of the operation of the output unit of  FIG. 23 . 
     First,  FIG. 38A  shows a state in which the expression unit  610  is disposed at the lowest point, that is, the expression unit  610  is closest to the bottom surface of the base unit  660 , for example, the bottom area  668 . 
     At this time, the first transmission member  615  of the expression unit  610  may be in a state supported by the moving unit  630 . For example, the first transmission member  615  may be in a state supported by the first support member  635 . Also, although not shown, the second transmission member  616  may be supported by the second support member  636 . 
     According to an optional embodiment, the first transmission member  615  and the first support member  635  may be separated from each other even when the expression unit  610  is disposed at the lowest point as the expression unit insert  620  with an increased width is caught by the top end of the base unit  660 . 
     Meanwhile, the first transmission member  615  and the first support member  635  may correspond to the first guide groove  663  of the base unit  660 . 
     Next, referring to  FIG. 38B , the expression unit  610  is in a state in which the expression unit  610  ascended, that is, moved in a direction away from the base unit  660 . The expression unit  610  may ascend while maintaining a state of being supported by the moving unit  630 , and more specifically, the expression unit  610  may have been ascended as the first support member  635  of the moving unit  630  supported and pushed up the first transmission member  615  of the expression unit  610 . 
     Also, although not shown, the expression unit  610  may have been ascended as the second support member  636  of the moving unit  630  supported and pushed up the second transmission member  616  of the expression unit  610 . 
     The movement of the moving unit  630  may be due to the magnetic unit  640 , and the moving unit  630  may move together with the magnetic unit  640 . 
     In detail, through a user&#39;s manipulation of the above-stated input pen  500 , the magnetic unit  640  may react with the moving unit  630  and the moving unit  630  may move. As a specific example, the magnetic body  510  of the input pen  500  may react with the magnetic unit  640  (e.g., the magnetic body  510  of the input pen  500  and the magnetic unit  640  may attract each other), and thus the magnetic unit  640  may move. 
     Therefore, the expression unit  610  may reach the highest point, that is, may be in a state farthest away from the base unit  660 . 
     The first support member  635  may ascend in correspondence to the first guide groove  663  of the base unit  660 . Also, although not shown, the second support member  636  may ascend in correspondence to the second guide groove  664 . 
     On the other hand, the first transmission member  615  may ascend and leave the first guide groove  663  of the base unit  660 . In this case, the first transmission member  615  may be adjacent to the engaging sliding area  665  adjacent to one side of the first guide groove  663 . 
     Also, although not shown, the second transmission member  616  may also ascend along the second guide groove  664  of the base unit  660  by the support of the second support member  636  and leave the second guide groove  664 . In this case, the second transmission member  616  may be adjacent to the engaging sliding area  665  adjacent to one side of the second guide groove  664 . 
     Then, referring to  FIG. 38C , the first transmission member  615  of the expression unit  610  maintains a state of being caught and stopped by the engaging portion  665 A after moving along the engaging sliding area  665  adjacent to the first guide groove  663 . 
     Also, the moving unit  630  may be spaced apart from the expression unit  610  by maintaining a state of being descended again as shown in  FIG. 38A . 
     Also, the second transmission member  616  of the expression unit  610  maintains a state of being caught and stopped by the engaging portion  665 A after moving along the engaging sliding area  665  adjacent to the second guide groove  664 . 
     In other words, the expression unit  610  of  FIG. 38C  is in a state lower than that of  FIG. 38B , and more specifically, the expression unit  610  of  FIG. 38C  may be in a state of being located between the lowest point in  FIG. 38A  and the highest point in  FIG. 38B . 
     Next, referring to  FIG. 38D , as compared to the state of  FIG. 38C , the expression unit  610  is in a state in which the expression unit  610  ascended, that is, moved in a direction away from the base unit  660 . The expression unit  610  may ascend while maintaining a state of being supported by the moving unit  630 , and more specifically, the expression unit  610  may have been ascended as the third support member  637  of the moving unit  630  supported and pushed up the first transmission member  615  of the expression unit  610  and the fourth support member  638  of the moving unit  630  supported and pushed up the second transmission member  616 . 
     Therefore, the expression unit  610  may reach the highest point, that is, may be in a state farthest away from the base unit  660 . 
     The first support member  635  may ascend in correspondence to the first guide groove  663  of the base unit  660 . Also, although not shown, the second support member  636  may ascend in correspondence to the second guide groove  664 . 
     On the other hand, the first transmission member  615  may ascend and leave the engaging portion  665 A of the base unit  660 . In this case, the first transmission member  615  may be adjacent to the connecting sliding area  666  adjacent to one side of the engaging portion  665 A. 
     Also, although not shown, the second transmission member  616  may ascend and leave the engaging portion  665 A of the base unit  660 . In this case, the second transmission member  616  may be adjacent to the connecting sliding area  666  adjacent to one side of the engaging portion  665 A. 
     Such ascending movement may be performed by a reset member IMGU. The reset member IMGU may be formed to react with the magnetic unit  640 . For example, the reset member IMGU may include a magnetic material to generate a magnetic field and, as a specific example, may include a permanent magnet. 
     The reset member IMGU may generate a magnetic field, and for example, the reset member IMGU may be formed, such that a repulsive force is applied to the magnetic unit  640 . To this end, the polarity and the arrangement direction of the reset member IMGU may be controlled. 
     The arrangement and the operation of the reset member IMGU may be determined in various ways, and detailed descriptions thereof will be given later. 
     Then,  FIG. 38E  shows a state in which the expression unit  610  is disposed at the lowest point, that is, the expression unit  610  is closest to the bottom surface of the base unit  660 , for example, the bottom area  668 . For example, in the state of  FIG. 38D , the expression unit  610  may descend without applying a separate force. 
     In detail, the first transmission member  615  may move along the connecting sliding area  666  and descend along the second guide groove  664  in correspondence to the second guide groove  664 . In detail, the second transmission member  616  may move along the connecting sliding area  666  and descend along the first guide groove  663  in correspondence to the first guide groove  663 . 
     After the expression unit  610  descends, the second transmission member  616  of the expression unit  610  may be in a state supported by the moving unit  630 . For example, the second transmission member  616  may be in a state supported by the first support member  635 . Also, although not shown, the first transmission member  615  may be supported by the second support member  636 . 
     As compared to  FIG. 38A , the height of the expression unit  610  is the same, and the expression unit  610  is rotated, wherein, instead of the first transmission member  615 , the second transmission member  616  corresponds to the first guide groove  663 . 
     In other words, through one cycle of ascending and descending of the expression unit  610 , the expression unit  610  may maintain a state of being rotated by about 180 degrees, and, when another cycle of ascending and descending is performed, the expression unit  610  may return to its original state as shown in  FIG. 38A . 
     As described above, by controlling the number of transmission members of an expression unit and the number of guide grooves corresponding thereto, the number of cycles in which the expression unit rotates and returns to its original state may be controlled. 
     According to an optional embodiment, the first transmission member  615  and the first support member  635  may be separated from each other even when the expression unit  610  is disposed at the lowest point as the expression unit insert  620  with an increased width is caught by the top end of the base unit  660 . 
       FIGS. 39 to 41  are diagrams for describing an example of arrangements and shapes of a reset member. 
     Referring to  FIG. 39 , the reset member IMGU may be disposed below the protruding feedback-based smart tablet  600 . 
     Also, the reset member IMGU may be formed to move in a first direction DU toward the protruding feedback-based smart tablet  600  or in a second direction DW away from the protruding feedback-based smart tablet  600 . 
     According to an optional embodiment, the reset member IMGU may correspond to a plurality of output units of the protruding feedback-based smart tablet  600  and initialize the plurality of output units at the same time. For example, the reset member IMGU may control protruding output units to descend again to return to a non-protruding state. 
     Also, according to an optional embodiment, the reset member IMGU may correspond to all of a plurality of output units of the protruding feedback-based smart tablet  600  and initialize the plurality of output units at the same time. For example, the reset member IMGU may control protruding output units to descend again to return to a non-protruding state. 
     Also, referring to  FIG. 40 , the reset member IMGU may be disposed below or inside the protruding feedback-based smart tablet  600 . 
     Also, the reset member IMGU may have a shape extending in one direction and may be formed to move in a first direction DA 1  and a second direction DA 2  opposite thereto. 
     Therefore, a plurality of output units of the protruding feedback-based smart tablet  600  may be sequentially initialized in one direction. For example, protruding output units may be descended again to return to a non-protruding state. 
     Also, according to an optional embodiment, referring to  FIG. 41 , the reset member IMGU may be disposed in a non-expression area NDA adjacent to the expression area DA of a protruding feedback-based smart tablet  600 ′. At this time, the reset member IMGU may be disposed inside the protruding feedback-based smart tablet  600 ′ and may be connected to a handle HD protruding to the outside. 
     The user may move the handle HD in one direction or a direction opposite thereto to move the reset member IMGU to the expression area DA, thereby sequentially initializing a plurality of output units in the expression area DA in one direction. For example, protruding output units may be descended again to return to a non-protruding state. 
     In a protruding feedback-based smart tablet of the present embodiment, one or more (e.g., a plurality of) output units may be arranged in an expression area to be spaced apart from one another. 
     The output units may protrude in response to a user&#39;s input. For example, the output units may protrude in response to an input pen manipulated by the user. As a specific example, a moving unit of each output unit may be moved by magnetic fields of the moving unit and the input pen. 
     An expression unit of the output unit may be moved by a moving unit and, as a specific example, may protrude. The user may easily sense a shape input by using the input pen by sensing the expression units of the protruding output units visually or tactilely. For example, a user having visual handicap may easily sense a character or a drawing input by the user by using an input pen by sensing a protruding shape of expression units of output units. 
     According to an optional embodiment, even when an input pen is removed, a moving unit supporting an expression unit may be configured to stay at a constant position, and thus a user may sense protruding expression units for a desired time. 
     Also, initialization may be performed by using a reset member when the user desires. For example, protruding expression units may be descended back to its original state, thereby facilitating an input operation of the user using an input pen. 
       FIG. 42  is a diagram for describing an output unit according to another embodiment of the present disclosure, and  FIG. 43  is an enlarged view of a portion of  FIG. 42 . 
     The output unit IU 8  may include a driving expression unit  1210  and a base unit  1230 . 
     The driving expression unit  1210  may include a magnetic material. 
     According to an optional embodiment, the driving expression unit  1210  may include a magnetic body, e.g., a permanent magnet. 
     According to an optional embodiment, when the input feedback-based smart pen includes a permanent magnet as described above, the driving expression unit  1210  may include a permanent magnet, or, according to another selective embodiment, iron, nickel, or a stainless steel-based alloy material. 
     The driving expression unit  1210  may be moved by a reaction with a magnetic body of the input pen, that is, magnetic fields of the driving expression unit  1210  and the magnetic body  110 . 
     Also, as a specific example, when the driving expression unit  1210  includes a permanent magnet, the N pole and S pole of the permanent magnet may be arranged in the lengthwise direction of the driving expression unit  1210 , which may be the Z-axis direction in  FIG. 42 . 
     The driving expression unit  1210  may perform a rotational movement, e.g., an angular movement with a certain angle. 
     The driving expression unit  1210  may move to protrude in one direction, and the driving expression unit  1210  may be relocated through ascending and descending movements at least in the lengthwise direction of the driving expression unit  1210 . Therefore, the driving expression unit  1210  may be moved to protrude in one direction, and a user may sense the movement of the driving expression unit  1210  tactilely or visually. 
     The driving expression unit  1210  may include a protrusion  1215  protruding from a side surface of a main body area  1211 . 
     Although not shown, according to an optional embodiment, the driving expression unit  1210  may include two protrusions  1215  protruding from two side surfaces of the main body area  1211  opposite to each other. 
     The protrusion  1215  may include a side surface  1215 A having at least a curved area and a fixing portion  1215 B. 
     The fixing portion  1215 B may have a flat surface in at least one area. 
     According to an optional embodiment, the main body area  1211  of the driving expression unit  1210  may have an elongated pillar-like shape. 
     In this case, an end of the driving expression unit  1210  may have a curved surface or the corners of the driving expression unit  1210  may be rounded. 
     The protrusion  1215  of the driving expression unit  1210  may be formed to be adjacent to an end portion of an area of the side surface of the main body area  1211  of the driving expression unit  1210  opposite to an end portion protruding toward a user in the lengthwise direction of the driving expression unit  1210 . 
     The driving expression unit  1210  may be disposed in a first accommodation unit  1231  of the base unit  1230  to be described later. 
     The base unit  1230  may be formed to accommodate the driving expression unit  1210 . 
     According to an optional embodiment, the base unit  1230  may include a first area MA corresponding to the driving expression unit  1210 . 
     As a specific example, the base unit  1230  may include the first accommodation unit  1231 . 
     The first accommodation unit  1231  may include a space for accommodating the driving expression unit  1210 . The first accommodation unit  1231  may be a space having a shape corresponding to that of the base unit  1230  from which a certain width and a certain length are removed. The first accommodation unit  1231  may be opened toward at least one surface of the base unit  1230 . Therefore, the driving expression unit  1210  accommodated in the first accommodation unit  1231  may maintain a protruding state while being accommodated in the first accommodation unit  1231 . 
     According to an optional embodiment, the first accommodation unit  1231  may have a shape open toward the top surface of the base unit  1230  and one side surface of the base unit  1230  connected thereto. 
     The length of the first accommodation unit  1231  may correspond to or be greater than at least the length of the driving expression unit  1210 . Therefore, the driving expression unit  1210  may be accommodated in the first accommodation unit  1231  not only when the driving expression unit  1210  moves in a first direction (e.g., ascending and descending in a direction opposite thereto), but also when the driving expression unit  1210  moves in a second direction intersecting with the first direction (e.g., the driving expression unit  1210  is laid by being rotated 90 degrees). 
     A driving groove  1235  may be formed to be connected to the first accommodation unit  1231 . The protrusion  1215  of the driving expression unit  1210  may correspond to the driving groove  1235 . 
     For example, when the driving expression unit  1210  is disposed in the first accommodation unit  1231 , the protrusion  1215  of the driving expression unit  1210  may correspond to the driving groove  1235 . 
       FIGS. 42 and 43  show that the driving groove  1235  have a shape penetrating through side surfaces of the base unit  1230 . Although not shown, according to another embodiment, the driving groove  1235  may be connected to the first accommodation unit  1231  and may not penetrate through the side surfaces of the base unit  1230 . In other words, the driving groove  1235  may have a groove shape instead of a penetrating shape. 
     The driving groove  1235  may include a first area  1235 A and a second area  1235 B. The first area  1235 A may be disposed closer to a second accommodation unit  1232  than the second area  1235 B is. 
     The first area  1235 A may be formed to support the protrusion  1215  when the driving expression unit  1210  (e.g., the protrusion  1215  of the driving expression unit  1210 ) descends. 
     To this end, the first area  1235 A may have an edge surface having a shape similar to that of the side surface  1215 A of the protrusion  1215  of the driving expression unit  1210 . For example, the first area  1235 A may have a curved surface. 
     Also, the first area  1235 A may have an appropriate width to facilitate the movement of the driving expression unit  1210  in the first direction (that is, an ascending direction) and the movement of returning in an opposite direction. Also, the first area  1235 A may be formed to extend in the first direction to be connected to the second area  1235 B. 
     The second area  1235 B may be connected to the first area  1235 A and may have a shape extending in a second direction intersecting with the first direction. As described above, the first direction is a direction in which the driving expression unit  1210  ascends or descends and is the Z-axis direction in  FIGS. 42 and 43 . 
     According to an optional embodiment, the second direction may be a direction orthogonal to the first direction, e.g., the X-axis direction in  FIGS. 42 and 43 . 
     For convenience of explanation, the first direction and the second direction will be used as the same meaning in descriptions below. 
     The second area  1235 B may be formed to correspond to the protrusion  1215  when the driving expression unit  1210  moves in the first direction and then moves in the second direction. 
     In other words, when the driving expression unit  1210  rotates, the protrusion  1215  may ascend from the first area  1235 A and then rotates by a certain angle to be disposed in the second area  1235 B. 
     The second area  1235 B may have a shape corresponding to a state in which the protrusion  1215  is rotated and disposed. For example, the second area  1235 B may have a curved surface. 
     Also, the second area  1235 B may have an appropriate width to facilitate the movement of the driving expression unit  1210  when the driving expression unit  1210  descends in a direction opposite to the first direction (e.g., rotating and descending) after the driving expression unit  1210  returns in the second direction. 
     Also, the second area  1235 B may have a shape similar to that of the first area  1235 A in a state in which the first area  1235 A is rotated. 
     The base unit  1230  may include a locking protrusion  1236  to maintain a state of the driving expression unit  1210  after the driving expression unit  1210  is disposed in the second area  1235 B. The locking protrusion  1236  includes a top surface  1236 A and a side surface  1236 B, wherein the top surface  1236 A and the side surface  1236 B of the locking protrusion  1236  may be connected to each other and correspond to the fixing portion  12156  of the protrusion  1215  according to the movement of the driving expression unit  1210 . 
     In other words, in the state shown in  FIG. 43 , when no separate external force is applied, the movement of the fixing portion  1215 B of the protrusion  1215  of the driving expression unit  1210 , e.g., a rotating movement, may be limited by the side surface  1236 B of the locking protrusion  1236 . 
     Also, when the driving expression unit  1210  moves and the protrusion  1215  corresponds to the second area  1235 B of the driving groove  1235 , the movement of the fixing portion  1215 B of the protrusion  1215  may be limited by the top surface  1236 A of the locking protrusion  1236 . 
       FIGS. 44A to 44D  are diagrams for describing the operation of the output unit of  FIG. 42 . 
     An operation of an information output device will be described with reference to  FIGS. 44A to 44D  in order. 
       FIG. 44A  shows a state in which the driving expression unit  1210  is descended (that is, not protruded), which may be a state before a user manipulates the input pen  100 . Alternatively,  FIG. 44A  may show a state after initialization is performed by using a reset member. 
     In the state, through a users manipulation of the input pen  100  (e.g., when the input pen  100  is moved to be close to the driving expression unit  1210 ), an ascending force may be applied to the driving expression unit  1210  by a magnetic field, and the driving expression unit  1210  may be rotated in a direction MD 1  direction by the protrusion  1215  and the driving groove  1235 . 
     For example, when a force is transmitted in the first direction to the driving expression unit  1210  by a magnetic field generated between the input pen  100  and the driving expression unit  1210  (that is, a repulsive force on the input pen  100 ), the protrusion  1215  is disposed in the second area  1235 B through the curved surface of the side surface  1215 A of the protrusion  1215  and the curved surface of the second area  1235 B of the driving groove  1235  or through curved surfaces of the first area  1235 A and the second area  1235 B, thereby facilitating rotation of the driving expression unit  1210 . 
       FIG. 44B  shows a state in which the driving expression unit  1210  is rotated in the direction MD 1  of  FIG. 44A  from the state of  FIG. 44A . 
     Therefore, the driving expression unit  1210  may ascend more than the state shown in  FIG. 44A  and the driving expression unit  1210  may have a protruding shape. 
     Then,  FIG. 44C  shows a state in which the driving expression unit  1210  is moved in a direction ND of  FIG. 44B . 
     In other words, the driving expression unit  1210  may move in a direction opposite to the first direction from the state of  FIG. 44B  (e.g., descend) to have the state shown in  FIG. 44C . 
     Also, according to an optional embodiment, even when no separate force is applied in the state of  FIG. 44B , the driving expression unit  1210  may move to the state of  FIG. 44C  by descending by gravity. 
     Also, in this case, as long as no certain force is transmitted to the driving expression unit  1210  in the first direction, the movement of the driving expression unit  1210  may be controlled. For example, the movement of the driving expression unit  1210  in the second direction or the rotational movement of the driving expression unit  1210  may be controlled by the side surface  1236 B of the locking protrusion  1236  of the base unit  1230 . 
     According to an optional embodiment, the side surface  1236 B of the locking protrusion  1236  may have a flat surface. 
     In this state, a user may sense a state in which the driving expression unit  1210  of the output unit IU 8  is protruding, for example, visually or tactilely. Also, according to an optional embodiment, the protruding state may be maintained. 
     Thereafter, an initialization process may be performed. 
     This initialization process may be performed through the reset member IMGU. The reset member IMGU may be formed to react with the driving expression unit  1210 . For example, the reset member IMGU may include a magnetic material to generate a magnetic field and, as a specific example, may include a permanent magnet. 
     The reset member IMGU may generate a magnetic field, and for example, the reset member IMGU may be formed, such that an attractive force or a repulsive force is applied driving expression unit  1210 . To this end, the polarity and the arrangement direction of the reset member IMGU may be controlled. 
     The arrangement and the operation of the reset member IMGU may be determined in various ways, and detailed descriptions thereof are identical to those given above. 
     The driving expression unit  1210  may ascend by a magnetic field generated between the reset member IMGU and the driving expression unit  1210 , may rotate by the configurations of the driving groove  1235  and the protrusion  1215 , and may maintain a non-protruding state as shown in  FIG. 44D . 
     In a protruding feedback-based smart tablet of the present embodiment, one or more (e.g., a plurality of) output units may be arranged in an expression area to be spaced apart from one another. 
     The output units may protrude in response to a user&#39;s input. For example, the output units may protrude in response to an input pen manipulated by the user. As a specific example, a moving unit of each output unit may be moved by magnetic fields of the moving unit and the input pen. 
     An expression unit of the output unit may be moved by a moving unit and, as a specific example, may protrude. The user may easily sense a shape input by using the input pen by sensing the expression units of the protruding output units visually or tactilely. For example, a user having visual handicap may easily sense a character or a drawing input by the user by using an input pen by sensing a protruding shape of expression units of output units. 
     According to an optional embodiment, even when an input pen is removed, a moving unit supporting an expression unit may be configured to stay at a constant position, and thus a user may sense protruding expression units for a desired time. 
     Also, initialization may be performed by using a reset member when the user desires. For example, protruding expression units may be descended back to its original state, thereby facilitating an input operation of the user using an input pen. 
     Also, in detail, a driving expression unit may easily move in a first direction (e.g., ascend) by a magnetic field and move in a second direction (e.g., clockwise rotation) by a protrusion and a driving groove of the driving expression unit. Also, as a fixing portion of the protrusion is supported by a locking protrusion of the driving groove, the rotational movement may be limited. Therefore, it is possible to easily maintain a state in which the protrusion of the driving expression unit is lowered (e.g., an OFF state). 
     Then, when a force is applied to the driving expression unit in a direction opposite to the first direction, the driving expression unit may rotate (e.g., rotate in the counterclockwise direction) by the protrusion and the driving groove of the driving expression unit, and, when the force is continuously applied or even when the force is removed, the driving expression unit may move in the direction opposite to the first direction. For example, the driving expression unit may descend. Also, as a fixing portion of the protrusion is supported by a locking protrusion of the driving groove, the rotational movement may be limited. Also, the protruding state of the driving expression unit may be maintained, e.g., an ON state. 
     Therefore, it is possible to easily switch and maintain ON and OFF states of the driving expression unit, reduce power consumption for movement of the driving expression unit, and improve the overall energy efficiency of an output unit. 
       FIG. 45  is a perspective view of a modified example of the one output unit of  FIG. 42 , and  FIG. 46  is an enlarged view of a portion of  FIG. 45 . In detail,  FIG. 46  is an enlarged view of a protrusion of a driving expression unit and a driving groove of a base unit of  FIG. 45 . 
     An output unit may include a driving expression unit  1210 ′ and a base unit  1230 ′. 
     For convenience of explanation, descriptions below will focus on differences from the above-described embodiment. 
     According to an optional embodiment, the driving expression unit  1210 ′ may include a magnetic body, e.g., a permanent magnet. 
     According to an optional embodiment, when the input feedback-based smart pen includes a permanent magnet as described above, the driving expression unit  1210 ′ may include a permanent magnet, or, according to another selective embodiment, iron, nickel, or a stainless steel-based alloy material. 
     The driving expression unit  1210 ′ may be moved by a reaction with a magnetic body of the input pen, that is, magnetic fields of the driving expression unit  1210 ′ and the magnetic body  110 . 
     At this time, as a specific example, when the driving expression unit  1210 ′ includes a permanent magnet, the N pole and S pole of the permanent magnet may be arranged in the lengthwise direction of the driving expression unit  1210 , which may be, for example, the first direction or the Z-axis direction in  FIG. 45 . 
     The driving expression unit  1210 ′ may move to protrude in one direction, and the driving expression unit  1210 ′ may be relocated through ascending and descending movements at least in the lengthwise direction of the driving expression unit  1210 ′. Therefore, the driving expression unit  1210 ′ may be moved to protrude in one direction, and a user may sense the movement of the driving expression unit  1210 ′ tactilely or visually. 
     The driving expression unit  1210 ′ may include a protrusion  1215 ′ protruding from a side surface of a main body area  1211 ′. Although not shown, according to an optional embodiment, the driving expression unit  1210 ′ may include two protrusions  1215 ′ protruding from two side surfaces of the main body area  1211 ′ opposite to each other. 
     According to an optional embodiment, a protrusion connecting portion  1218 ″ may be further included between the protrusion  1215 ′ and the main body area  1211 ″. The protrusion connecting portion  1218 ″ protrudes from a side surface of the main body area  1211 ′ and may have a width greater than that of the protrusion  1215 ′. The protrusion connecting portion  1218 ″ may be disposed at a position to not to be caught by a locking protrusion  1236 ″ of a base unit  1230 ″ to be described later. 
     The protrusion connecting portion  1218 ″ is formed between the main body area  1211 ″ and the protrusion  1215 ′ of the driving expression unit  1210 ′ to have a width greater than that of the protrusion  1215 ′ to distribute a force locally exerted on the protrusion  1215 ′ during a rotation movement and a movement limitation by a driving groove  1235 ′ and the locking protrusion  1236 ′ to be described later, thereby reducing damage or deformation of the protrusion  1215 ′ and facilitating rotation of the protrusion  1215 ′. 
     The protrusion  1215 ′ may include a side surface  1215 A′ having at least a curved area and a fixing portion  12156 ′. 
     The fixing portion  1215 B′ may have a flat surface in at least one area. According to an optional embodiment, the main body area  1211 ′ of the driving expression unit  1210 ′ may have a pillar-like shape elongated in one direction, that is, the lengthwise direction. 
     In this case, an end of the driving expression unit  1210 ′ may have a curved surface or the corners of the driving expression unit  1210 ′ may be rounded. 
     The protrusion  1215 ′ of the driving expression unit  1210 ′ may be formed to be adjacent to an end portion of an area of the side surface of the main body area  1211 ′ of the driving expression unit  1210 ′ opposite to an end portion protruding toward a user in the lengthwise direction of the driving expression unit  1210 ′. 
     The driving expression unit  1210 ′ may be disposed in a first accommodation unit  1231 ′ of the base unit  1230 ′ to be described later. 
     The base unit  1230 ′ may be formed to accommodate the driving expression unit  1210 ′. 
     In an alternative embodiment, the base unit  1230 ′ may include a first area  1 MA′ corresponding to the driving expression unit  1210 ′. 
     As a specific example, the base unit  1230 ′ may include a first accommodation unit  1231 ′. 
     The first accommodation unit  1231 ′ may include a space accommodating the driving expression unit  1210 ′. The first accommodation unit  1231 ′ may be a space having a shape corresponding to that of the base unit  1230 ′ from which a certain width and a certain length are removed. The first accommodation unit  1231 ′ may be opened toward at least one surface of the base unit  1230 ′. Therefore, the driving expression unit  1210 ′ accommodated in the first accommodation unit  1231 ′ may maintain a protruding state while being accommodated in the first accommodation unit  1231 ′. 
     According to an optional embodiment, the first accommodation unit  1231 ′ may have a shape open toward the top surface of the base unit  1230 ′ and one side surface of the base unit  1230 ′ connected thereto. 
     The length of the first accommodation unit  1231 ′ may correspond to or be greater than at least the length of the driving expression unit  1210 ′. Therefore, the driving expression unit  1210 ′ may be accommodated in the first accommodation unit  1231 ′ not only when the driving expression unit  1210 ′ moves in a first direction (e.g., ascending and descending in a direction opposite thereto), but also when the driving expression unit  1210 ′ moves in a second direction intersecting with the first direction (e.g., the driving expression unit  1210 ′ is laid by being rotated 90 degrees). 
     The base unit  1230 ′ may include the driving groove  1235 ′ and the locking protrusion  1236 ′. 
     The driving groove  1235 ′ may be formed to be connected to the first accommodation unit  1231 ′. The protrusion  1215 ′ of the driving expression unit  1210 ′ may correspond to the driving groove  1235 ′. 
     For example, when the driving expression unit  1210 ′ is disposed in the first accommodation unit  1231 ′, the protrusion  1215 ′ of the driving expression unit  1210 ′ may correspond to the driving groove  1235 ′. 
       FIGS. 45 and 46  show that the driving groove  1235 ′ have a shape penetrating through side surfaces of the base unit  1230 ′. Although not shown, according to another embodiment, the driving groove  1235 ′ may be connected to the first accommodation unit  1231 ′ and may not penetrate through the side surfaces of the base unit  1230 ′. In other words, the driving groove  1235 ′ may have a groove shape instead of a penetrating shape. 
     The driving groove  1235 ′ may include a first area  1235 A′ and a second area  1235 B′. The first area  1235 A′ may be disposed closer to a second accommodation unit  1232 ′ than the second area  1235 B′ is. 
     The first area  1235 A′ may be formed to support the protrusion  1215 ′ when the driving expression unit  1210 ′ (e.g., the protrusion  1215 ′ of the driving expression unit  1210 ′) descends. 
     To this end, the first area  1235 A′ may have an edge surface having a shape similar to that of the side surface  1215 A′ of the protrusion  1215 ′ of the driving expression unit  1210 ′. For example, the first area  1235 A′ may have a curved surface. 
     Also, the first area  1235 A′ may have an appropriate width to facilitate the movement of the driving expression unit  1210 ′ in the first direction (that is, an ascending direction) and the movement of returning in an opposite direction. Also, the first area  1235 A′ may be formed to extend in the first direction to be connected to the second area  1235 B′. 
     The second area  12356 ′ may be connected to the first area  1235 A′ and may have a shape extending in a second direction intersecting with the first direction. As described above, the first direction is a direction in which the driving expression unit  1210 ′ ascends or descends and is the Z-axis direction in  FIGS. 45 and 46 . 
     Also, according to an optional embodiment, the second direction may be a direction orthogonal to the first direction, e.g., the X-axis direction in  FIG. 45 . 
     The second area  12356 ′ may be formed to correspond to the protrusion  1215 ′ when the driving expression unit  1210 ′ moves in the first direction and then moves in the second direction. 
     In other words, when the driving expression unit  1210 ′ rotates, the protrusion  1215 ′ may ascend from the first area  1235 A′ and then rotates by a certain angle to be disposed in the second area  12356 ′. 
     The second area  12356 ′ may have a shape corresponding to a state in which the protrusion  1215 ′ is rotated and disposed. For example, the second area  12356 ′ may have a curved surface. 
     Also, the second area  12356 ′ may have an appropriate width to facilitate the movement of the driving expression unit  1210 ′ when the driving expression unit  1210 ′ descends in a direction opposite to the first direction (e.g., rotating and descending) after the driving expression unit  1210 ′ returns in the second direction. 
     Also, the second area  12356 ′ may have a shape similar to that of the first area  1235 A in a state in which the first area  1235 A′ is rotated. 
     The base unit  1230 ′ may include a locking protrusion  1236 ′ to maintain a state of the driving expression unit  1210 ′ after the driving expression unit  1210 ′ is disposed in the second area  12356 ′. In other words, the fixing portion  12156 ′ of the protrusion  1215 ′ of the driving expression unit  1210 ′ is disposed on a top surface  1236 A′ of the locking protrusion  1236 ′, and thus the driving expression unit  1210 ′ may be fixed. According to an optional embodiment, the top surface  1236 A′ of the locking protrusion  1236 ′ may have a flat surface. 
     According to an optional embodiment, the base unit  1230 ′ may have a separation area  1238 ′ based on a boundary line  1237 ′ overlapping the driving groove  1235 ′. For example, when an edge of the separation area  1238 ′ correspond to the boundary line  1237 ′ and the separation area  1238 ′ is separated from the remaining of the base unit  1230 ′, the driving groove  1235 ′ may have an open shape. 
     According to an optional embodiment, the driving expression unit  1210 ′ may be disposed in the first accommodation unit  1231 ′ before disposing or attaching the separation area  1238 ′ in or to the remaining of the base unit  1230 ′ and the separation area  1238 ′ may be disposed in or attached to the remaining of the base unit  1230 ′, and thus the driving expression unit  1210 ′ may be easily disposed in the base unit  1230 ′. 
     The operation of the output unit of the present embodiment is similar to that of  FIGS. 44A to 44D  described above, and thus detailed descriptions thereof will be omitted. 
       FIGS. 47 and 48  are views of modified examples of a driving expression unit. 
     Referring to  FIG. 47 , a driving expression unit  1210 ″ may include a first magnetic unit  1 PA′ and a second magnetic unit  1 PB′. The first magnetic unit  1 PA′ and the second magnetic unit  1 PB′ may have different polarities from each other. For example, the first magnetic unit  1 PA′ may have an N pole, and the second magnetic unit  1 PB′ may have an S pole. Alternatively, according to another embodiment, the first magnetic unit  1 PA′ may have an S pole and the second magnetic unit  1 PB′ may have an N pole. 
     Also, according to another embodiment, referring to  FIG. 48 , a driving expression unit  1210 ″ may include the first magnetic unit  1 PA′, the second magnetic unit  1 PB′, and a cover layer  1 MB′. 
     The first magnetic unit  1 PA′ and the second magnetic unit  1 PB′ may have different polarities from each other. For example, the first magnetic unit  1 PA′ may have an N pole, and the second magnetic unit  1 PB′ may have an S pole. Alternatively, according to another embodiment, the first magnetic unit  1 PA′ may have an S pole and the second magnetic unit  1 PB′ may have an N pole. 
     The cover layer  1 MB′ may cover at least one surface of each of the first magnetic unit  1 PA′ and the second magnetic unit  1 PB′. As a specific example, the cover layer  1 MB′ may be formed to surround the first magnetic unit  1 PA′ and the second magnetic unit  1 PB′. Therefore, the cover layer  1 MB′ may protect the first magnetic unit  1 PA′ and the second magnetic unit  1 PB′, and the cover layer  1 MB′ may include various materials. For example, the cover layer  1 MB′ may include an organic layer or an inorganic layer, and more particularly, may include an organic material like a resin or an inorganic material like a ceramic. 
     The above-stated driving expression unit of  FIGS. 47 and 48  may be selectively applied to the above-stated output unit of  FIG. 43 or 45 , and various modifications may be made therein. 
       FIG. 49  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure,  FIG. 50  is an enlarged view of a driving expression unit of  FIG. 49 , and  FIG. 51  is a perspective plan view of the driving expression unit of  FIG. 49  viewed from above. 
     The output unit IU 8  may include a driving expression unit  2200  and a base unit  2300 . 
     The driving expression unit  2200  may include a magnetic material. 
     The driving expression unit  2200  will be described in detail with reference to  FIGS. 50 and 51 . 
     The driving expression unit  2200  may include a magnetic unit  2170  and a magnetic body  2180 . 
     According to an optional embodiment, the magnetic unit  2170  may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  2170  may include a first magnetic unit  2171  and a second magnetic unit  2172 . In detail, the first magnetic unit  2171  and the second magnetic unit  2172  have different polarities from each other. For example, the first magnetic unit  2171  may have an N pole, and the second magnetic unit  2172  may have an S pole. Alternatively, according to another embodiment, the first magnetic unit  2171  may have an S pole, and the second magnetic unit  2172  may have an N pole. 
     The magnetic body  2180  has a property of being magnetized in a magnetic field, is, for example, adjacent to the magnetic unit  2170 , and may be magnetized by the magnetic unit  2170  to influence the direction of a magnetic field generated by the magnetic unit  2170 . 
     According to an optional embodiment, the magnetic body  2180  may include various materials. For example, the magnetic body  2180  may include iron, and, according to another embodiment, may include nickel or cobalt. 
     The magnetic body  2180  may be tilted at a certain angle with respect to the magnetic unit  2170 . 
     According to an optional embodiment, the magnetic unit  2170  and the magnetic body  2180  may be arranged to be eccentric to each other. For example, the center axis of the magnetic unit  2170  and the center axis of the magnetic body  2180  may be misaligned from each other instead of being parallel with each other. 
     According to an optional embodiment, as shown in  FIGS. 50 and 51 , the magnetic unit  2170  may be disposed in the center area of the driving expression unit  2100 , and the magnetic body  2180  may have a shape extending from the center area of the driving expression unit  2200  toward the outer surface of the driving expression unit  2100 . 
     According to an optional embodiment, one side surface of the magnetic body  2180  may be exposed to one side surface of the driving expression unit  2100 . Therefore, a shape in which the magnetic body  2180  is disposed inside the driving expression unit  2200  may be easily implemented. 
     According to an optional embodiment, the center axis of the magnetic unit  2170  may be parallel with the center axis of the driving expression unit  2100 , and the center axis of the magnetic body  2180  may be misaligned to the center axis of the driving expression unit  2200  without being parallel therewith. 
     Due to the misalignment between the center axes of the magnetic unit  2170  and the magnetic body  2180  (that is, eccentricity), the axial direction of a magnetic field generated by a combination of the magnetic unit  2170  and the magnetic body  2180  or the magnetic axis direction of the driving expression unit  2200  may not be parallel with the center axis of the driving expression unit  2200  and may be tilted by a certain angle. Therefore, it is possible to easily generate the torque of the driving expression unit  2200  and control the smooth movement of the driving expression unit  2100 , thereby improving the expression precision of the output unit IU 8  and reduce power consumption thereof. 
     The driving expression unit  2200  may perform a rotational movement, e.g., an angular movement with a certain angle. 
     The driving expression unit  2200  may move to protrude in one direction, and the driving expression unit  2200  may be relocated through ascending and descending movements at least in the lengthwise direction of the driving expression unit  2100 . Therefore, the driving expression unit  2200  may be moved to protrude in one direction, and a user may sense the movement of the driving expression unit  2200  tactilely or visually. 
     The driving expression unit  2200  may include a protrusion  2150  protruding from a side surface of a main body area  2210 . 
     According to an optional embodiment, as shown in  FIG. 51 , the driving expression unit  2200  may include two protrusions  2150  protruding from side surfaces of the main body area  2210  opposite to each other. 
     The protrusion  2150  may include a side surface  2150 A having at least a curved area and a fixing portion  21508 . 
     The fixing portion  2150 B may have a flat surface in at least one area. 
     According to an optional embodiment, the main body area  2210  of the driving expression unit  2200  may have an elongated pillar-like shape. 
     In this case, an end of the driving expression unit  2200  may have a curved surface or the corners of the driving expression unit  2200  may be rounded. 
     For example, from among areas of the driving expression unit  2100 , an end portion from which the driving expression unit  2200  protrudes toward a user may have a curved surface. 
     In addition, a bottom surface  2120  of the driving expression unit  2100 , that is, a surface opposite to the end portion from which the driving expression unit  2200  protrudes toward a user may also have a curved surface. In other words, the shape that the width of the bottom surface  2120  of the driving expression unit  2200  decreases in the downward direction enables stable arrangement of the magnetic unit  2170 . For example, the magnetic unit  2170  may be disposed in parallel with the center axis of the driving expression unit  2100 . 
     The protrusion  2150  of the driving expression unit  2200  may be formed to be adjacent to an end portion of an area of the side surface of the main body area  2210  of the driving expression unit  2200  opposite to an end portion protruding toward a user in the lengthwise direction of the driving expression unit  2100 . 
     The driving expression unit  2200  may be disposed in a first accommodation unit  2310  of the base unit  2300 . 
     As a specific example, the base unit  2300  may include the first accommodation unit  2310 . 
     The first accommodation unit  2310  may include a space accommodating the driving expression unit  2100 . The first accommodation unit  2310  may be a space having a shape corresponding to that of the base unit  2300  from which a certain width and a certain length are removed. The first accommodation unit  2310  may be opened toward at least one surface of the base unit  2300 . Therefore, the driving expression unit  2200  accommodated in the first accommodation unit  2310  may maintain a protruding state while being accommodated in the first accommodation unit  2310 . 
     According to an optional embodiment, the first accommodation unit  2310  may have a shape open toward the top surface of the base unit  2300  and one side surface of the base unit  2300  connected thereto. 
     The length of the first accommodation unit  2310  may correspond to or be greater than at least the length of the driving expression unit  2100 . Therefore, the driving expression unit  2200  may be accommodated in the first accommodation unit  2310  not only when the driving expression unit  2200  moves in a first direction (e.g., ascending and descending in a direction opposite thereto), but also when the driving expression unit  2200  moves in a second direction intersecting with the first direction (e.g., the driving expression unit  2200  is laid by being rotated 90 degrees). 
     The base unit  2300  may include a driving groove  2350  and a locking protrusion  2360 . 
     The driving groove  2350  may be formed to be connected to the first accommodation unit  2310 . The protrusion  2150  of the driving expression unit  2200  may correspond to the driving groove  2350 . 
     For example, when the driving expression unit  2200  is disposed in the first accommodation unit  2310 , the protrusion  2150  of the driving expression unit  2200  may correspond to the driving groove  2350 . 
       FIG. 49  shows that the driving groove  2350  have a shape penetrating through side surfaces of the base unit  2300 . Although not shown, according to another embodiment, the driving groove  2350  may be connected to the first accommodation unit  2310  and may not penetrate through the side surfaces of the base unit  2300 . In other words, the driving groove  2350  may have a groove shape instead of a penetrating shape. 
     The driving groove  2350  may include a first area and a second area, which are the same as those described in the above-described embodiments, and thus detailed descriptions thereof will be omitted. 
     The base unit  2300  may include the locking protrusion  2360  to maintain a state of the driving expression unit  2200  after the driving expression unit  2200  is disposed in a second area of the driving groove  2350 . 
       FIG. 52  is an enlarged view of a modified example of the driving expression unit of  FIG. 49 . 
     Referring to  FIG. 52 , a driving expression unit  2200 ′ may include a magnetic unit  2170 ′. According to an optional embodiment, the magnetic unit  2170 ′ may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  2170 ′ may include a first magnetic unit  2171 ′ and a second magnetic unit  2172 ′. In detail, the first magnetic unit  2171 ′ and the second magnetic unit  2172 ′ have different polarities from each other. For example, the first magnetic unit  2171 ′ may have an N pole, and the second magnetic unit  2172 ′ may have an S pole. Alternatively, according to another embodiment, the first magnetic unit  2171 ′ may have an S pole, and the second magnetic unit  2172 ′ may have an N pole. 
     A direction C 2 ′ of the magnetic axis of the magnetic unit  2170 ′ may be tilted at a certain angle with respect to the driving expression unit  2200 ′. 
     According to an optional embodiment, the direction C 2 ′ of the magnetic axis of the magnetic unit  2170 ′ may be misaligned with the center axis of the driving expression unit  2200 ′ without being parallel therewith. 
     According to an optional embodiment, the center axis of the magnetic unit  2170 ′ may be tilted to form a certain angle instead of being parallel with the lengthwise direction of the driving expression unit  2200 ′. 
     Due to the misalignment between the direction C 2 ′ of the magnetic axis of the magnetic unit  2170 ′ and the center axis of the driving expression unit  2200 ′, it is possible to easily generate the torque of the driving expression unit  2200 ′ and control the smooth movement of the driving expression unit  2200 ′, thereby improving the expression precision of an information output device and reduce power consumption thereof. 
     The magnetic unit  2170 ′ may be disposed to overlap at least the center point of the driving expression unit  2200 ′ in the lengthwise direction. 
     According to an optional embodiment, the magnetic unit  2170 ′ may have an extended length to reach the center point of the driving expression unit  2200 ′ in the lengthwise direction. 
     Therefore, a torque may be easily generated at the driving expression unit  2200 ′ by changing the center of gravity of the driving expression unit  2200 ′. 
     A movement of the driving expression unit  2200  or  2200 ′ using an input pen (e.g., a protruding movement) is similar to the driving of the output unit of the above-stated embodiment, and more particularly, the embodiment of  FIG. 42  or  FIG. 49 , and thus detailed descriptions thereof will be omitted. 
       FIG. 53  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure, and  FIGS. 54 and 55  are diagrams for describing the operation of the output unit of  FIG. 53 . 
     The output unit IU 8  of the present embodiment may include a base unit  3130 , a driving unit  3140 , and an expression unit  3110 . 
     The expression unit  3110  may move according to the movement of the driving unit  3140  to be described later and may move upward and downward at least in the lengthwise direction of the expression unit  3110 . Therefore, the expression unit  3110  may be moved to protrude in one direction, and a user may sense the movement of the expression unit  3110  tactilely or visually. 
     The expression unit  3110  may include an expression surface  3111  and a support surface  3112 . 
     The support surface  3112  is a surface from among areas of the expression unit  3110  facing the driving unit  3140  and may constitute a lower area of the expression unit  3110  and contact the driving unit  3140 . The driving unit  3140  may transmit a force to the expression unit  3110  through the support surface  3112 . For example, a driving surface  3140   a  of the driving unit  3140  may contact the support surface  3112  and allow the support surface  3112  to move in a first direction, that is, the Z-axis direction in  FIG. 53 . 
     The expression surface  3111  is the outermost (e.g., the topmost) surface from among areas of the expression unit  3110  and may include an area to be recognized by a user. 
     For example, the entire area of the expression unit  3110  may be recognized by a user or only the expression surface  3111  may be recognized. For example, a user may sense the movement of the expression unit  3110  through contact with the expression surface  3111 , and the user may easily sense the movement of the expression unit  3110  through visual sensing of the expression surface  3111 . 
     According to an optional embodiment, the expression surface  3111  may include a curved surface. 
     The expression unit  3110  may have various shapes. The expression unit  3110  may include a pillar-like area. For example, the expression unit  3110  may include an area having a shape similar to that of a cylinder. 
     In this case, a protruding area of the expression unit  3110  may have a curved surface and may also have rounded corners. 
     The expression unit  3110  may include various materials and may include an insulating material as a light and durable material. For example, the expression unit  3110  may include a resin-based organic material. According to another embodiment, the expression unit  3110  may include an inorganic material, such as a ceramic material. 
     Also, according to another selective embodiment, the expression unit  3110  may include a material like a metal or glass. 
     According to an optional embodiment, a support unit  3170  may be further disposed. For example, the support unit  3170  may include an elongated area. 
     According to an optional embodiment, one end of the support unit  3170  may be extended to support the driving unit  3140  to be described later, and the movement of the driving unit  3140  may be performed while being supported by the one end of the support unit  3170 . 
     According to an optional embodiment, the support unit  3170  may be formed in correspond to a through portion of the base unit  3130 . 
     According to an optional embodiment, the support unit  3170  may include a magnetic material, thereby efficiently generating a magnetic field between the driving unit  3140  and an input pen or between the driving unit  3140  and a reset member to reduce the power consumption of the output unit IU 8 . 
     The base unit  3130  may include a first accommodation unit  3131  and a second accommodation unit  3132 . 
     The first accommodation unit  3131  and the second accommodation unit  3132  may be arranged adjacent to each other and may not overlap each other. 
     According to an optional embodiment, the first accommodation unit  3131  and the second accommodation unit  3132  may be spaced apart from each other. 
     According to another selective embodiment, the first accommodation unit  3131  and the second accommodation unit  3132  may be connected through a through hole. 
     The above-stated support unit  3170  may be disposed in the first accommodation unit  3131 , and one area of the support unit  3170  may be extended and disposed in the second accommodation unit  3132  through a through hole. 
     Although not shown, according to an optional embodiment, a driving groove (not shown) may be formed in the second accommodation unit  3132  of the base unit  3130 . For example, driving grooves (not shown) may be formed on inner side surfaces of the second accommodation unit  3132  of the base unit  3130  facing each other. 
     The base unit  3130  may have an elongated shape to accommodate the driving unit  3140  and may be formed to completely surround the driving unit  3140 . 
     According to an optional embodiment, the base unit  3130  may include a boundary  3133  between the first accommodation unit  3131  and the second accommodation unit  3132 . 
     The first accommodation unit  3131  and the second accommodation unit  3132  may be separated by the boundary  3133 . 
     According to an optional embodiment, a through hole may be formed at the boundary  3133 , such that an area of the support unit  3170  extends and passes therethrough. 
     Also, the base unit  3130  may include an inlet  3130   a , and the inlet  3130   a  may be connected to the second accommodation unit  3132 . The expression unit  3110  may move, such that the length of a portion thereof protruding out of the base unit  3130  through the inlet  3130   a  varies. 
     The driving unit  3140  may be disposed at the base unit  3130 . The driving unit  3140  may be disposed in the second accommodation unit  3132 . 
     The driving unit  3140  may be driven by an input pen and perform an angular movement or a rotational movement. The expression unit  3110  may move up and down by the driving unit  3140 . 
     According to an optional embodiment, a magnetic unit  3150  may be disposed in the driving unit  3140 , for example, in the inner space of the driving unit  3140 . For example, the magnetic unit  3150  may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  3150  may include a first area (e.g., an N pole or an S pole) and a second area (e.g., an S pole or an N pole) having different polarities, and the first area and the second area having different polarities may be arranged in a direction toward the expression unit  3110  during a rotation of the driving unit  3140 , e.g., the Z-axis direction. 
     For example, in  FIG. 53 , the first area and the second area of the magnetic unit  3150  having different polarities may be arranged in a direction toward the expression unit  3110 , e.g., the Z-axis direction. 
     The driving unit  3140  may include the driving surface  3140   a  on at least the outer surface, and the driving surface  3140   a  may be formed to support the expression unit  3110 , thereby providing a driving force for the vertical movement of the expression unit  3110 . 
     According to an optional embodiment, the driving surface  3140   a  of the driving unit  3140  may include a curved surface as the outer surface. According to a more specific embodiment, the driving surface  3140   a  of the driving unit  3140  may include a boundary line having a circle-like shape. 
     The driving unit  3140  may include a driving control unit  3149 . 
     The driving position of the driving unit  3140  may be controlled through the driving control unit  3149 . For example, when the driving unit  3140  moves, the driving unit  3140  may perform an angular motion or a rotational motion around the driving control unit  3149 . 
     According to an optional embodiment, the center axis of the driving unit  3140  and the center axis driving control unit  3149  may not be coaxial with each other and may be eccentric. 
     Also, according to an optional embodiment, the magnetic unit  3150  may not coaxial with the central axis of the driving unit  3140  and, for example, may be disposed to overlap an area of the driving control unit  3149 . 
     Therefore, it is possible to easily generate the torque with respect to the driving unit  3140  to allow the driving unit  3140  to perform an angular movement or a rotational movement, thereby efficiently performing a movement with respect to the expression unit  3110  and improving the expression precision of the output unit IU 8 . Also, power consumption of the output unit IU 8  may be reduced. 
     Although not shown, the driving unit  3140  may include a first driving member (not shown) and a second driving member (not shown) and may include a separation space (not shown) therebetween. 
     External surfaces of the first driving member (not shown) and the second driving member (not shown) may each include the driving surface  3140   a  on at least one surface to support the expression unit  3110  during a movement of the driving unit  3140 , thereby providing a driving force to the expression unit  3110 . For example, an outer boundary line (e.g., a circle) of the driving unit  3140  including the driving surface  3140   a  shown in  FIG. 53  may be a boundary line of the first driving member (not shown) or the second driving member (not shown). 
     According to an optional embodiment, the outer surfaces of the first driving member (not shown) and the second driving member (not shown) may each include a curved surface. For example, the driving surface  3140   a  may include a curved surface. 
     For example, the first driving member (not shown) and the second driving member (not shown) may each have a shape similar to that of a rotating body and may each have a disk-like shape. 
     Therefore, a natural driving force may be provided to the support surface  3112  of the expression unit  3110  during a rotation or an angular movement of the first driving member (not shown) and the second driving member (not shown), thereby allowing the expression unit  3110  to efficiently perform a continuous and smooth movement. 
     The driving control unit  3149  may be disposed on at least one side surface (e.g., both side surfaces) of the driving unit  3140 . 
     According to an optional embodiment, the driving control unit  3149  may protrude in a direction away from a side surface of the driving unit  3140  (a direction protruding outwardly in  FIG. 53 ), and, according to an optional embodiment, the protruding shape of the driving control unit  3149  may correspond to a driving groove (not shown) when the base unit  3130  includes the driving groove (not shown). 
     For example, the driving unit  3140  may be moved by a magnetic field by an input pen manipulated by a user, and, as a specific example, the driving unit  3140  may move up and down due to a repulsive force and an attractive force with respect to the magnetic unit  3150  in the driving unit  3140 . At this time, the driving unit  3140  may move up and down while rotating around the driving control unit  3149 . 
     According to an optional embodiment, the driving unit  3140  may move while the driving control unit  3149  of the driving unit  3140  is being disposed in an area of the base unit  3130 , e.g., a driving groove (not shown) of the second accommodation unit  3132 . 
     A first movement area  3145  and a second movement area  3148  may be arranged in a space between the first driving member (not shown) and the second driving member (not shown). 
     The first movement area  3145  and the second movement area  3148  may be areas that become the references of the highest point and the lowest point during a movement of the driving unit  3140 , respectively. 
     According to an optional embodiment, a connection area  3147  may be disposed between the first movement area  3145  and the second movement area  3148 , and the connection area  3147  may include a curved surface. 
     For example, as shown in  FIG. 53 , when the first movement area  3145  is located at the bottom, the driving unit  3140  may be located at the lowest point, and thus the expression unit  3110  may also be in a state of being located at the lowest point, and more particularly, a state in which a protruding height of the expression unit  3110  from the base unit  3130  is the smallest. For example, it may be a state in which the expression unit  3110  of the output unit IU 8  is arranged to be unrecognizable by a user, and more particularly, a state in which the expression unit  3110  does not protrude from a surrounding member (e.g., a housing) to not to be tactilely sensed. 
     In this case, the first movement area  3145  may be supported by the top end of the support unit  3170 . 
     Next, as shown in  FIG. 54 , when a magnetic field is formed between an input used by a user and the driving unit  3140 , the driving unit  3140  may move. For example, when an attractive force is applied between the magnetic unit  3150  disposed in the driving unit  3140  and the input pen, an end portion of the magnetic unit  3150  (an end portion corresponding to a polarity to which the attractive force is applied) may be disposed to be close to the input pen, and the connection area  3147  may be supported by the top end of the support unit  3170 . Referring to  FIG. 54 , the driving unit  3140  may ascend, that is, the top surface of the driving unit  3140  may ascend. Therefore, the expression unit  3110  may also ascend slightly by a height H 1  in  FIG. 54 . 
     According to an optional embodiment, since the driving unit  3140  rotates around the driving control unit  3149 , the driving control unit  3149  may maintain its position. 
     Next, the driving unit  3140  may continuously move by a continuous magnetic field as shown in  FIG. 55 . For example, the second movement area  3148  may be supported by the top end of the support unit  3170 . Referring to  FIG. 55 , the driving unit  3140  may ascend, that is, the top surface of the driving unit  3140  may ascend. Therefore, the expression unit  3110  may also ascend, and the state shown in  FIG. 55  may indicate the highest point of the expression unit  3110 . 
     According to an optional embodiment, since the driving unit  3140  rotates around the driving control unit  3149 , the driving control unit  3149  may maintain its position. 
     According to an optional embodiment, a movement from the state of  FIG. 53  to the state of  FIG. 55  may be continuous. The state of  FIG. 54  is for describing one process. When the state of  FIG. 53  is changed to the state of  FIG. 54 , the driving unit  3140  and the expression unit  3110  may continue to move from the state of  FIG. 54  without stopping and may be in the state of  FIG. 55 . 
     For example,  FIGS. 53 and 55  may show states in which the expression unit  3110  may maintain a stationary state, and  FIG. 54  may show a state in which the expression unit  3110  is moving. 
     According to an optional embodiment, the sequential moving process of  FIGS. 53 to 55  may also be applied to embodiments to be described later. 
     In this state, a user may sense a state in which the driving expression unit  3110  of the output unit IU 8  is protruding, for example, visually or tactilely. Also, according to an optional embodiment, the protruding state may be maintained. 
     Thereafter, an initialization process may be performed. 
     This initialization process may be performed through the reset member IMGU. The reset member IMGU may be formed to react with the driving unit  3140 . For example, the reset member IMGU may include a magnetic material to generate a magnetic field and, as a specific example, may include a permanent magnet. 
     The reset member IMGU may generate a magnetic field, and for example, the reset member IMGU may be formed, such that an attractive force is applied to an area of the driving unit  3140 . To this end, the polarity and the arrangement direction of the reset member IMGU may be controlled. 
     The arrangement and the operation of the reset member IMGU may be determined in various ways, and detailed descriptions thereof are identical to those given above. 
     The driving unit  3140  rotates by a magnetic field generated between the reset member IMGU and the driving unit  3140 , and thus the expression unit  3110  may descend. For example, the expression unit  3110  may maintain the state as shown in  FIG. 53 . 
     During a rotational movement of the driving unit  3140 , the support unit  3170  may support at least one area of the connection area  3147  while supporting the first movement area  3145  and before supporting the second movement area  3148 , Therefore, the driving unit  3140  may naturally move, and thus the movement of the expression unit  3110  may be precisely controlled. 
     A distance between the driving surface  3140   a  and the first movement area  3145  may be different from a distance between the driving surface  3140   a  and the second movement area  3148 . For example, the distance between the driving surface  3140   a  and the first movement area  3145  may be greater than the distance between the driving surface  3140   a  and the second movement area  3148 . 
     According to an optional embodiment, a distance between the first movement area  3145  from the center axis of the driving unit  3140  in terms of the shape of the driving unit  3140  may be smaller than a distance between the second movement area  3148  from the center axis of the driving unit  3140  in terms of the shape of the driving unit  3140 . 
     According to an optional embodiment, a distance from the driving control unit  3149  to the first movement area  3145  may be the same as or similar to a distance from the driving control unit  3149  to the second movement area  3148 . According to an additional selective embodiment, a distance from the driving control unit  3149  to the connection area  3147  may be the same or similar to a distance from the driving control unit  3149  to the second movement area  3145 . 
     For example, the connection area  3147  may correspond to at least one area of a circumference having a radius around the center point of the driving control unit  3149 , and the first movement area  3145  and the second movement area  3148  may have flat surfaces extending in parallel with each other from areas corresponding to the diameter of the circumference facing each other. 
     Therefore, when the driving unit  3140  rotates around the driving control unit  3149  and the support unit  3170  supports the first movement area  3145 , the second movement area  3148 , and the connection area  3147 , the driving control unit  3149  may be maintained at the same position or similar positions. 
     Also, when supported by the support unit  3170 , the connection area  3147  supported by the support unit  3170  includes a curved surface or a surface having a shape close to an arc, and thus a smooth movement of the driving unit  3140  may be efficiently performed. 
     Although not shown, the second accommodation unit  3132  of the base unit  3130  may include a groove that is at least larger than the driving control unit  3149  to accommodate the driving control unit  3149 . 
     The above descriptions correspond to a case in which the first movement area  3145 , the second movement area  3148 , and the connection area  3147  are arranged in an area of the driving unit  3140  including the driving surface  3140   a , e.g., a space between a first driving member (not shown) and a second driving member (not shown). This also applies to embodiments described below. 
     According to another selective embodiment, the first movement area  3145 , the second movement area  3148 , and the connection area  3147  may be arranged in an area of the driving unit  3140  including the driving surface  3140   a , e.g., an outer surface of the first driving member (not shown) or the second driving member (not shown). 
     Also, according to another selective embodiment, there may be an area of the driving unit  3140  including the driving surface  3140   a , e.g., one first driving member (not shown) or one second driving member (not shown). The first movement area  3145 , the second movement area  3148 , and the connection area  3147  may be arranged on both side surfaces thereof, and thus the driving control unit  3149  may be disposed in an area surrounded by the first movement area  3145 , the second movement area  3148 , and the connection area  3147 . 
     Also, these various selective embodiments, that is, structures in which the first movement area  3145 , the second movement area  3148 , and the connection area  3147  are arranged on an outer surface of a shape smaller than the first driving member (not shown) or the second driving member (not shown) may include various modifications. Also, these various embodiments may also apply to embodiments described below. 
     In an information output unit of the present embodiment, a driving unit moves by a magnetic field generated between the driving unit and an input pen. Therefore, an expression unit may also easily move in a first direction (e.g., ascend) and may move and rotate while maintaining a certain area through a driving control unit. 
     For example, according to the polarity of a magnetic unit disposed inside the driving unit, the driving unit may rotate and ascend. 
     Therefore, ascending and descending of the driving unit become smooth, natural, and precise movements, thereby reducing the irregular intermittentness of ascending and descending of the expression unit and facilitating the control of flexible and precise movements. 
     Also, an initialization may be easily performed by making the driving unit to descend by using a reset member. Therefore, the expression unit may ascend and descend, thereby facilitating implementation of an ON state or an OFF state of an output unit. 
     Also, even when a force applied to the driving unit through support, e.g., support for a first movement area and a second movement area through a support unit, is removed during an ascending movement or a descending movement of the driving unit, the driving unit may maintain its state of movement. 
     In other words, after the driving unit ascends to a state in which a second movement area is supported by an extension of the driving unit from a state in which a first movement area is supported by the extension, the driving unit may maintain the state in which the second movement area is supported by the extension even when an input pen is removed. 
     Also, a driving control unit provided in a driving unit of the present embodiment is eccentric with the center axis of the driving unit. Therefore, a torque may be easily generated with respect to the driving unit to implement ascending and descending of the driving unit through rotational movements, thereby enabling precise, smooth, and natural movement control for an expression unit. 
     According to an optional embodiment, a magnetic unit provided in a driving unit may be disposed to overlap a driving control unit. For example, the center of the magnetic unit may overlap the driving control unit. 
       FIG. 56  is a schematic perspective view of an output unit according to another embodiment of the present disclosure,  FIG. 57  is a cross-sectional view taken along a line V-V of  FIG. 56 ,  FIG. 59  is a schematic perspective view for describing a driving unit of  FIG. 56 ,  FIG. 60  is a front view of the driving unit viewed in one direction of  FIG. 59 , and  FIG. 61  is a partial perspective view of an area of a base unit of  FIG. 56  viewed in one direction. 
     Referring to  FIGS. 56 to 61 , the output unit IU 8  of the present embodiment includes at least one information output unit, and  FIG. 56  shows one information output unit. In other words, the output unit IU 8  of  FIG. 56  may be one information output unit. 
     The output unit IU 8  may include a base unit  3230 , a driving unit  3240 , and an expression unit  3210 . 
     The expression unit  3210  may move according to the movement of the driving unit  3240  to be described later and may move upward and downward at least in the lengthwise direction of the expression unit  3210 . Therefore, the expression unit  3210  may be moved to protrude in one direction, and a user may sense the movement of the expression unit  3210  tactilely or visually. 
     The expression unit  3210  may include an expression surface  3211  and a support surface  3212 . 
     The support surface  3212  is a surface from among areas of the expression unit  3210  facing the driving unit  3240  and may constitute a lower area of the expression unit  3210  and contact the driving unit  3240 . The driving unit  3240  may transmit a force to the expression unit  3210  through the support surface  3212 . 
     The expression surface  3211  may include the outermost surface from among areas of the expression surface  3211 , e.g., an area to be recognized by a user. 
     For example, the entire area of the expression unit  3210  may be recognized by a user or only the expression surface  3211  may be recognized. For example, a user may sense the movement of the expression unit  3210  through contact with the expression surface  3211 , and the user may easily sense the movement of the expression unit  3210  through visual sensing of the expression surface  3211 . 
     According to an optional embodiment, the expression surface  3211  may include a curved surface. 
     The expression unit  3210  may have various shapes. The expression unit  3210  may include a pillar-like area. For example, the expression unit  3210  may include an area having a shape similar to that of a cylinder as shown in  FIG. 56 . 
     In this case, a protruding area of the expression unit  3210  may have a curved surface and may also have rounded corners. 
     The expression unit  3210  may include various materials and may include an insulating material as a light and durable material. For example, the expression unit  3210  may include a resin-based organic material. According to another embodiment, the expression unit  3210  may include an inorganic material, such as a ceramic material. 
     Also, according to another selective embodiment, the expression unit  3210  may include a material like a metal or glass. 
     According to an optional embodiment, a support unit  3270  may be further disposed. 
     According to an optional embodiment, one end of an extension  3271  of the support unit  3270  may be extended to support the driving unit  3240  to be described later, and the driving unit  3240  may move while being supported by the one end of the extension  3271 . 
     According to an optional embodiment, the extension  3271  may be formed in correspond to a through hole  3230 H of the base unit  3230 . 
     According to an optional embodiment, the support unit  3270  may include a body unit  3272 , and the body unit  3272  may be connected to the extension  3271 . 
     According to an optional embodiment, the body unit  3272  and the extension  3271  of the support unit  3270  may be integrated with each other. 
     According to an optional embodiment, a base  3280  may be further included, such that the body unit  3272  is disposed thereon. 
     The base  3280  may be disposed to surround the bottom surface and the side surface of the body unit  3272 . 
     According to an optional embodiment, the base  3280  may include a protrusion  3281  in one area, and one area of the protrusion  3281  may be exposed on the side surface of the base unit  3230  to facilitate handling of the base  3280 . 
     The base unit  3230  includes an accommodation space. For example, the base unit  3230  may include a first accommodation unit  3231  and a second accommodation unit  3232 . 
     The first accommodation unit  3231  and the second accommodation unit  3232  may be arranged adjacent to each other and may not overlap each other. 
     According to an optional embodiment, the first accommodation unit  3231  and the second accommodation unit  3232  may be spaced apart from each other. 
     According to another selective embodiment, the first accommodation unit  3231  and the second accommodation unit  3232  may be connected through the through hole  3230 H. 
     The support unit  3270  or the base  3280  may be disposed in the first accommodation unit  3231 . 
     According to an optional embodiment, a driving groove  3234  may be formed in the second accommodation unit  3232  of the base unit  3230 . For example, driving grooves  3234  may be formed on inner side surfaces of the second accommodation unit  3232  of the base unit  3230  facing each other. According to an optional embodiment, the driving grooves  3234  may be formed in one direction, e.g., a downward direction. 
     According to an optional embodiment, the driving groove  3234  may be formed in the form of a groove or a penetrating area penetrating to the outside. When the driving groove  3234  does not penetrate to the outside of the base unit  3230  and is formed in the form of a groove by removing an inner area of the base unit  3230 , the exposure of the base unit  3230  to the outside is reduced, thereby reducing contamination and damage of the driving unit  3240  and enabling precise control of the driving unit  3240 . 
     The base unit  3230  may have an elongated shape to accommodate the driving unit  3240  and may be formed to completely surround the driving unit  3240 . 
     According to an optional embodiment, the base unit  3230  may include a boundary  3233  between the first accommodation unit  3231  and the second accommodation unit  3232 . 
     The first accommodation unit  3231  and the second accommodation unit  3232  may be separated by the boundary  3233 . 
     According to an optional embodiment, the through hole  3230 H may be formed at the boundary  3233 . 
     Also, the base unit  3230  may include an inlet  3230   a , and the inlet  3230   a  may be connected to the second accommodation unit  3232 . The expression unit  3210  may move, such that the length of a portion thereof protruding out of the base unit  3230  through the inlet  3230   a  varies. 
     The driving unit  3240  may be disposed at the base unit  3230 . The driving unit  3240  may be disposed in the second accommodation unit  3232 . 
     According to an optional embodiment, a magnetic unit  3250  may be disposed in the driving unit  3240 , for example, in the inner space of the driving unit  3240 . For example, the magnetic unit  3250  may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  3250  may include a first area (e.g., an N pole or an S pole) and a second area (e.g., an S pole or an N pole) having different polarities, and the first area and the second area having different polarities may be arranged in a direction toward the expression unit  3210  during a rotation of the driving unit  3240 , e.g., the Z-axis direction. 
     For example, in  FIGS. 57 and 58 , the first area and the second area of the magnetic unit  3250  having different polarities may be arranged in a direction toward the expression unit  3210 , e.g., the Z-axis direction. 
     The driving unit  3240  may include the driving surface  3241   a  on at least the outer surface, and the driving surface  3241   a  may be formed to support the expression unit  3210 , thereby providing a driving force for the vertical movement of the expression unit  3210 . 
     According to an optional embodiment, the driving surface  3241   a  of the driving unit  3240  may include a curved surface as the outer surface. According to a more specific embodiment, the driving surface  3241   a  of the driving unit  3240  may include a boundary line having a circle-like shape. 
     The driving unit  3240  may include a driving control unit  3249 . 
     The driving position of the driving unit  3240  may be controlled through the driving control unit  3249 . For example, when the driving unit  3240  moves, the driving unit  3240  may perform an angular motion or a rotational motion around the driving control unit  3249 . 
     According to an optional embodiment, the center axis of the driving unit  3240  and the center axis driving control unit  3249  may not be coaxial with each other and may be eccentric. 
     Also, according to an optional embodiment, the magnetic unit  3250  may not coaxial with the central axis of the driving unit  3240  and, for example, may be disposed to overlap an area of the driving control unit  3249 . 
     Therefore, it is possible to easily generate the torque with respect to the driving unit  3240  to allow the driving unit  3240  to perform an angular movement or a rotational movement, thereby efficiently performing a movement with respect to the expression unit  3210  and improving the expression precision of the output unit IU 8 . Also, power consumption of the output unit IU 8  may be reduced. 
     The driving unit  3240  will be described in more detail with reference to  FIGS. 59 to 61 . 
       FIG. 59  is a schematic perspective view for describing the driving unit of  FIG. 56 , and  FIG. 60  is a front view of the driving unit viewed from one direction of  FIG. 59 .  FIG. 61  is a partial perspective view of an area of a base unit of  FIG. 56  viewed from one direction. 
     Referring to  FIGS. 59 and 60 , the driving unit  3240  may include a first driving member  3243  and a second driving member  3244  and may include a separation space SA therebetween. 
     External surfaces of the first driving member  3243  and the second driving member  3244  may each include the driving surface  3241   a  on at least one surface to support the expression unit  3210  during a movement of the driving unit  3240 , thereby providing a driving force to the expression unit  3210 . 
     According to an optional embodiment, outer surfaces of the first driving member  3243  and the second driving member  3244  may include curved surfaces. For example, the first driving member  3243  and the second driving member  3244  may each have a shape similar to that of a rotating body and may each have a disk-like shape. 
     Therefore, a natural driving force may be provided to the support surface  3212  of the expression unit  3210  during a rotation or an angular movement of the first driving member  3243  and the second driving member  3244 , thereby allowing the expression unit  3210  to efficiently perform a continuous and smooth movement. 
     Driving control units  3249  may be arranged on at least one side surfaces of the first driving member  3243  and the second driving member  3244 , e.g., surfaces of the first driving member  3243  and the second driving member  3244  opposite to side surfaces of the first driving member  3243  and the second driving member  3244  facing each other. 
     According to an optional embodiment, the driving control unit  3249  may have a protruding shape, and the protruding shape may correspond to the driving groove  3234  of the base unit  3230 . 
     For example, the driving unit  3240  may move by a magnetic field, and, as a specific example, the driving unit  3240  may move up and down due to a repulsive force and an attractive force with respect to the magnetic unit  3250  in the driving unit  3240 . At this time, the driving unit  3240  may move up and down while rotating around the driving control unit  3249 , wherein the driving unit  3240  may rotate while the driving control unit  3249  of the driving unit  3240  is being disposed in the driving groove  3234 . For example, the driving control unit  3249  may rotate within the driving groove  3234 . Also, according to an optional embodiment, a slight vertical movement may occur while the driving control unit  3249  rotates within the driving groove  3234 . 
     A first movement area  3245  and a second movement area  3248  may be arranged in the separation space SA between the first driving member  3243  and the second driving member  3244 . 
     The first movement area  3245  and the second movement area  3248  may be areas that become the references of the highest point and the lowest point during a movement of the driving unit  3240 , respectively. 
     For example, when the first movement area  3245  is disposed at the bottom, the driving unit  3240  may be located at the lowest point, and thus the expression unit  3210  may also be located at the lowest point, and more particularly, may be in a state in which a protruding height of the expression unit  3210  from the base unit  3230  is the smallest. 
     Also, when the second movement area  3248  is disposed at the bottom, the driving unit  3240  may be located at the highest point, and thus the expression unit  3210  may also be located at the highest point, and more particularly, may be in a state in which a protruding height of the expression unit  3210  from the base unit  3230  is the largest. 
     According to an optional embodiment, the first movement area  3245  and the second movement area  3248  may be supported by the above-stated extension  3271 . In other words, when the driving unit  3240  is moving, the extension  3271  is disposed in correspondence to the separation space SA between the first driving member  3243  and the second driving member  3244 , thereby supporting the first movement area  3245  and the second movement area  3248  at corresponding time points. 
     According to an optional embodiment, a connection area  3247  may be disposed between the first movement area  3245  and the second movement area  3248 , and the connection area  3247  may include a curved surface. 
     During a rotational movement of the driving unit  3240 , the extension  3271  may support at least one area of the connection area  3247  while supporting the first movement area  3245  and before supporting the second movement area  3248 , Therefore, the driving unit  3240  may naturally move, and thus the movement of the expression unit  3210  may be precisely controlled. 
     A distance between the driving surface  3241   a  and the first movement area  3245  may be different from a distance between the driving surface  3241   a  and the second movement area  3248 . For example, the distance between the driving surface  3241   a  and the first movement area  3245  may be greater than the distance between the driving surface  3241   a  and the second movement area  3248 . 
     According to an optional embodiment, a distance between the first movement area  3245  from the center axis of the driving unit  3240  in terms of the shape of the driving unit  3240  may be smaller than a distance between the second movement area  3248  from the center axis of the driving unit  3240  in terms of the shape of the driving unit  3240 . 
     According to an optional embodiment, a distance from the driving control unit  3249  to the first movement area  3245  may be the same as or similar to a distance from the driving control unit  3249  to the second movement area  3248 . According to an additional selective embodiment, a distance from the driving control unit  3249  to the connection area  3247  may be the same or similar to a distance from the driving control unit  3249  to the second movement area  3245 . 
     For example, the connection area  3247  may correspond to at least one area of a circumference having a radius around the center point of the driving control unit  3249 , and the first movement area  3245  and the second movement area  3248  may have shapes of flat surfaces extending in parallel with each other from areas corresponding to the diameter of the circumference facing each other. 
     Therefore, when the driving unit  3240  rotates around the driving control unit  3249  and the support unit  3270  supports the first movement area  3245 , the second movement area  3248 , and the connection area  3247 , the driving control unit  3249  may be maintained at the same position or similar positions. 
     Also, when supported by the support unit  3270 , the connection area  3247  includes a curved surface or a surface having a shape close to an arc, and thus a smooth movement of the driving unit  3240  may be efficiently performed. 
     Referring to  FIG. 61 , the second accommodation unit  3232  of the base unit  3230  may include a first groove  3233   c  and a second groove  3233   d.    
     The first groove  3233   c  and the second groove  3233   d  may extend long. The first driving member  3243  and the second driving member  3244  may be arranged in correspondence to the first groove  3233   c  and the second groove  3233   d , respectively. Therefore, when a driving force is transmitted to the driving unit  3240  through an input pen or a reset member, the driving unit  3240  may perform an angular movement or a rotational movement while the first driving member  3243  and the second driving member  3244  of the driving unit  3240  are being respectively arranged in correspondence to the first groove  3233   c  and the second groove  3233   d . As a result, the driving unit  3240  may stably move, thereby facilitating precise control of the movement of the expression unit  3210 . 
     As an alternative embodiment, a protrusion area PT may be formed between the first groove  3233   c  and the second groove  3233   d . For example, the above-described through hole  3230 H may be formed in the protrusion area PT. 
     The extension  3271  of the support unit  3270  may correspond to the through hole  3230 H. At this time, the extension  3271  may protrude through the through hole  3230 H and protrude more than the protrusion area PT. In this case, the first movement area  3245  and the second movement area  3248  may be supported by the extension  3271  at corresponding time points. 
     According to an optional embodiment, the extension  3271  may not protrude more than the protrusion area PT. In this case, the first movement area  3245  and the second movement area  3248  may be supported by the protrusion area PT at corresponding time points. 
     Also, according to an optional embodiment, the extension  3271  or the protrusion area PT may not support the driving unit  3240  or may only temporarily support the driving unit  3240 . In this case, the driving control unit  3249  may be supported by an area of the second accommodation unit  3232 , e.g., an boundary surface of the driving groove  3234 . 
       FIGS. 62A and 62B  are views of a support unit of the output unit of  FIG. 56  and a modified example thereof. 
     Referring to  FIG. 62A , as described above, the support unit  3270  of the present embodiment may include the body unit  3272 , wherein the body unit  3272  may be connected to the extension  3271  and has a plate-like shape widely extending in directions intersecting with a direction in which the extension  3271  extends. 
     Also, as a modified example, referring to  FIG. 62B , a support unit  3270 ′ includes a body unit  3272 ′, wherein the body unit  3272 ′ may be connected to an extension  3271 ′, a top end member  3271   b ′ may be formed at one end of the extension  3271 ′, and the top end member  3271   b ′ may include a material different from a material constituting the extension  3271 ′. 
     According to an optional embodiment, the top end member  3271   b ′ may include a material, such as a plastic or a ceramic. For example, the extension  3271 ′ may include a magnetic material and the top end member  3271   b ′ may include a plastic. 
       FIGS. 63 and 64  are views of an expression unit of  FIG. 56  and a modified example thereof. 
     Referring to  FIG. 63 , the expression unit  3210  of the present embodiment described above may include an expression surface  3211  and a support surface  3212 . 
     Also, as a modified example, referring to  FIG. 64 , an expression unit  3210 ′ may include an expression surface  3211 ′ and a support surface  3212 ′ and may include a magnetic body IMT therein. The driving of the expression unit  3210 ′ through the driving unit  3240  may be performed more efficiently through the magnetic body IMT of the expression unit  3210 ′, and power consumption therefor may be reduced. 
       FIG. 65  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure,  FIG. 66  is a diagram for describing a driving unit of  FIG. 65 , and  FIG. 67  is a diagram for describing a guide groove of the output unit of  FIG. 65 . 
     The output unit IU 8  of the present embodiment may include a base unit  4130 , a driving unit  4140 , and an expression unit  4110 . 
     Also, the base unit  4130  may include one or more guide grooves  4135 . 
     The expression unit  4110  may move according to the movement of the driving unit  4140  to be described later and may move upward and downward at least in the lengthwise direction of the expression unit  4110 . 
     Therefore, the expression unit  4110  may be moved to protrude in one direction, and a user may sense the movement of the expression unit  4110  tactilely or visually. 
     The expression unit  4110  may include an expression surface  4111  and a support surface  4112 . 
     The support surface  4112  is a surface from among areas of the expression unit  4110  facing the driving unit  4140  and may constitute a lower area of the expression unit  4110  and contact the driving unit  4140 . The driving unit  4140  may transmit a force to the expression unit  4110  through the support surface  4112 . For example, a driving surface  4140   a  of the driving unit  4140  may contact the support surface  4112  and allow the support surface  4112  to move in a first direction, that is, the Z-axis direction in  FIG. 65 . 
     The expression surface  4111  is the outermost (e.g., the topmost) surface from among areas of the expression unit  4110  and may include an area to be recognized by a user. 
     For example, the entire area of the expression unit  4110  may be recognized by a user or only the expression surface  4111  may be recognized. For example, a user may sense the movement of the expression unit  4110  through contact with the expression surface  4111 , and the user may easily sense the movement of the expression unit  4110  through visual sensing of the expression surface  4111 . 
     According to an optional embodiment, the expression surface  4111  may include a curved surface. 
     The expression unit  4110  may have various shapes. The expression unit  4110  may include a pillar-like area. For example, the expression unit  4110  may include an area having a shape similar to that of a cylinder. 
     In this case, a protruding area of the expression unit  4110  may have a curved surface and may also have rounded corners. 
     The expression unit  4110  may include various materials and may include an insulating material as a light and durable material. For example, the expression unit  4110  may include a resin-based organic material. According to another embodiment, the expression unit  4110  may include an inorganic material, such as a ceramic material. 
     Also, according to another selective embodiment, the expression unit  4110  may include a material like a metal or glass. 
     According to an optional embodiment, a support unit  4170  may be further disposed. 
     For example, the support unit  4170  may include an extension member  4171 . 
     According to an optional embodiment, one end of the extension member  4171  may be extended to overlap or support one area of the driving unit  4140  to be described later. 
     According to an optional embodiment, the support unit  4170  may include a body member  4172 , and the extension member  4171  may be connected to the body member  4172 . 
     As a specific example, the extension member  4171  may have a shape extending from the body member  4172  in a direction close to the expression unit  4110 . 
     According to an optional embodiment, the body member  4172  and the extension member  4171  of the support unit  4170  may be integrated with each other. 
     Although not shown, according to an optional embodiment, a base (not shown) may be further included to support the body member  4172 , and the body member  4172  may be disposed on the base (not shown). 
     According to an optional embodiment, the support unit  4170  may include a magnetic material, and, as a specific example, the extension member  4171  may include a magnetic material. Therefore, in the case of generating a magnetic field for the driving unit  4140 , the magnitude of the magnetic field may be increased, and the power consumption of the output unit IU 8  may be reduced by efficiently generating the magnetic field. 
     The base unit  4130  may include a first accommodation unit  4131 , a second accommodation unit  4132 , and the guide groove  4135 . 
     The first accommodation unit  4131  and the second accommodation unit  4132  may be arranged adjacent to each other and may not overlap each other. 
     According to an optional embodiment, the first accommodation unit  4131  and the second accommodation unit  4132  may be spaced apart from each other. 
     According to another selective embodiment, the first accommodation unit  4131  and the second accommodation unit  4132  may be connected through a through hole. 
     According to an optional embodiment, the above-stated support unit  4170  may be disposed in the first accommodation unit  4131 . Although not shown, according to another additional embodiment, an area of the support unit  4170 , e.g., an area of the extension member  4171 , may be extended and disposed in the second accommodation unit  4132  through the through hole. 
     The guide groove  4135  may be formed in the second accommodation unit  4132 . For example, the guide grooves  4135  may be formed on inner side surfaces of the second accommodation unit  4132  of the base unit  4130  facing each other. According to another selective embodiment, the guide groove  4135  may be formed on only one of the inner side surfaces. 
     The guide groove  4135  may have a shape of a through-hole. According to another embodiment, the guide groove  4135  may have a shape of a groove that is not exposed to the outside of the base unit  4130 . 
     Referring to  FIG. 67 , the guide groove  4135  may include a first groove  4135   a , a second groove  4135   b , and a connection groove  4135   c.    
     The first groove  4135   a  and the second groove  4135   b  may be spaced apart from each other, and, according to an optional embodiment, an intermediate portion  4137  may be formed between the first groove  4135   a  and the second groove  4135   b.    
     The first groove  4135   a  and the second groove  4135   b  may be formed to be parallel with each other. As a specific example, the first groove  4135   a  and the second groove  4135   b  may be arranged side by side in a direction parallel to one of directions in which the expression unit  4110  moves up and down. 
     The connection groove  4135   c  may be formed to interconnect between the first groove  4135   a  and the second groove  4135   b . According to an optional embodiment, the connection groove  4135   c  may include a curved surface. 
     According to an optional embodiment, a top surface  4138  of the intermediate portion  4137 , that is, the surface of an area closest to the expression unit  4110  may include a curved surface, and, as a specific example, may have a curved surface parallel to the connection groove  4135   c.    
     Therefore, at least one area of the connection groove  4135   c  may have a shape similar to an arc, and, according to an optional embodiment, the connection groove  4135   c  may include an area having a shape corresponding to a semicircular arc. 
     According to an optional embodiment, the guide groove  4135  may have a shape similar to the alphabet “U”. 
     The base unit  4130  may have an elongated shape to accommodate the driving unit  4140  and may be formed to completely surround the driving unit  4140 . 
     According to an optional embodiment, the base unit  4130  may include a boundary  4133  between the first accommodation unit  4131  and the second accommodation unit  4132 . 
     The first accommodation unit  4131  and the second accommodation unit  4132  may be separated by the boundary  4133 . 
     Although not shown, according to an optional embodiment, a through hole may be formed in the boundary  4133 , and an area of the support unit  4170  may be disposed to extend and pass therethrough. 
     Also, the base unit  4130  may include an inlet  4130   a , and the inlet  4130   a  may be connected to the second accommodation unit  4132 . The expression unit  4110  may move, such that the length of a portion thereof protruding out of the base unit  4130  through the inlet  4130   a  varies. 
     According to an optional embodiment, the base unit  4130  may include an open area  4139 . In detail, the open area  4139  may be formed to be connected to the first accommodation unit  4131 . 
     The open area  4139  may facilitate placement, replacement, or repair of the support unit  4170 . 
     The driving unit  4140  may be disposed at the base unit  4130 . The driving unit  4140  may be disposed in the second accommodation unit  4132 . 
     The driving unit  4140  may be driven by a magnetic field generated between the driving unit  4140  and an input pen (or a reset member) and perform an angular movement or a rotational movement. The expression unit  4110  may move up and down by the driving unit  4140 . 
     According to an optional embodiment, referring to  FIG. 66 , a magnetic unit  4150  may be disposed in the driving unit  4140 , e.g., in the inner space. For example, the magnetic unit  4150  may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  4150  may include a first area  4151  (e.g., an N pole or an S pole) and a second area  4152  (e.g., an S pole or an N pole) having different polarities, and the first area  4151  and the second area  4152  having different polarities may be arranged in a direction toward the expression unit  4110  during a rotation of the driving unit  4140 , e.g., the Z-axis direction. 
     According to an optional embodiment, when the driving unit  4140  is at the lowest point, the center axis of the magnetic unit  4150  may not coaxial with the center axis of the expression unit  4110  and may be misaligned. When the driving unit  4140  is driven by a magnetic field, a torque may be generated at the driving unit  4140 , thereby facilitating a rotational movement or an angular movement of the driving unit  4140 . 
     For example, in  FIG. 65 , the first area and the second area of the magnetic unit  4150  having different polarities may be arranged in a direction toward the expression unit  4110 , e.g., the Z-axis direction. 
     According to an optional embodiment, the outer surface of the driving unit  4140  may include a driving surface, and at least an area thereof (e.g., a corner area) may include a curved surface. Also, the outer surface of the driving unit  4140  may be formed to support the expression unit  4110 , thereby providing a driving force for the vertical movement of the expression unit  4110 . 
     Therefore, the movement of the expression unit  4110  may be efficiently performed, and the expression precision of the output unit IU 8  may be improved. Also, power consumption of the output unit IU 8  may be reduced. 
     The driving unit  4140  may include a driving control unit  4142 . 
     The driving position of the driving unit  4140  may be controlled through the driving control unit  4142 . For example, when the driving unit  4140  moves, the driving unit  4140  may move while the driving control unit  4149  is being disposed in the guide groove  4135 . 
     According to an optional embodiment, the driving control unit  4142  may perform a movement similar to the shape of the guide groove  4135 , e.g., the shape of the alphabet “U”. 
     The driving control unit  4142  may have a protruding shape. For example, the driving control unit  4142  may have a shape protruding from a side surface of the driving unit  4140 , and the driving control unit  4142  may be disposed in the guide groove  4135 . 
     According to an optional embodiment, the driving control unit  4142  may include an outer surface  4142   a  and an inner surface  4142   b.    
     The outer surface  4142   a  is a surface facing a surface close to the outer surface of the guide groove  4135 , e.g., the outer surface of the base unit  4130 , when the driving unit  4140  is disposed in the guide groove  4135 . 
     The inner surface  4142   b  is a surface facing an inner surface of the guide groove  4135 , e.g., the intermediate portion  4137 , when the driving unit  4140  is disposed in the guide groove  4135 . 
     According to an optional embodiment, the outer surface  4142   a  may include a curved surface. Therefore, when the driving unit  4140  moves in the guide groove  4135 , the outer surface  4142   a  may stably move in the first groove  4135   a , the second groove  4135   b , and the connection groove  4135   c . According to an optional embodiment, when the connection groove  4135   c  includes a curved surface or at least one area of an arc, friction with the outer surface  4142   a  may be reduced, thereby facilitating smooth movement of the driving unit  4140  and improving efficiency of the movement of the driving unit  4140 . 
     According to an optional embodiment, at least one area of the inner surface  4142   b  may include a flat surface. Therefore, the driving unit  4140  may stably move. For example, when the driving control unit  4142  ascends and is disposed on the top surface  4138  of the intermediate portion  4137 , the driving control unit  4142  may be stably placed on the top surface  4138  of the intermediate portion  4137 . 
       FIGS. 68A and 68B  are views of a support unit of the output unit of  FIG. 65  and a modified example thereof. 
     Referring to  FIG. 68 a   , as described above, the support unit  4170  of the present embodiment may include the body member  4172 , and the body member  4172  may be disposed to be connected to the extension member  4171  and to support the extension member  4171 . 
     Also, as a modified example, referring to  FIG. 68B , a support unit  4170 ′ may include a body unit  4172 ′, and the body unit  4172 ′ may be disposed to be connected to an extension  4171 ′. Also, a top end member  4171   b ′ may be formed at one end of the extension  4171 ′, and the top end member  4171   b ′ may include a material different from a material constituting the extension  4171 ′. 
     According to an optional embodiment, the top end member  4171   b ′ may include a material, such as a plastic or a ceramic. For example, the extension  4171 ′ may include a magnetic material and the top end member  4171   b ′ may include a plastic. 
       FIGS. 69A and 69B  are views of an expression unit of the output unit of  FIG. 65  and a modified example thereof. 
     Referring to  FIG. 69A , the expression unit  4110  of the present embodiment described above may include the expression surface  4111  and the support surface  4112 . 
     Also, as a modified example, referring to  FIG. 69B , an expression unit  4110 ′ may include an expression surface  4111 ′ and a support surface  4112 ′ and may include the magnetic body IMT therein. The driving of the expression unit  4110 ′ through the driving unit  4140  may be performed more efficiently through the magnetic body IMT of the expression unit  4110 ′, and power consumption therefor may be reduced. 
       FIGS. 70 to 73  are diagrams for describing the operation of the output unit of  FIG. 65 . 
       FIG. 70  shows that, as compared to  FIG. 65 , the driving unit  4140  ascends, and thus the expression unit  4110  also ascends. 
     For example, when an input pen is located in the proximity of the driving unit  4140  through a user&#39;s manipulation of the input pen, the driving unit  4140  may move as a magnetic field is generated between the driving unit  4140  and the input pen. For example, when an attractive force is applied between the second area  4152  of the magnetic unit  4150  disposed in the driving unit  4140  and the input pen, the driving unit  4140  may ascend by the attractive force between the magnetic unit  4150  and the input pen. For example, the driving unit  4140  may ascend by the height H 1 . 
     Next,  FIG. 71  shows that the driving unit  4140  continuously moves by a magnetic field. In other words, the driving unit  4140  ascends and performed an angular movement as a repulsive force is applied to the first area  4151  of the magnetic unit  4150  and an attractive force is applied to the second area  4152  of the magnetic unit  4150 . 
     At this time, the driving control unit  4142  moves within the guide groove  4135 , and thus the driving control unit  4142  may be disposed on the top surface  4138  of the intermediate portion  4137 . 
     Through the driving of the driving unit  4140 , the expression unit  4110  may ascend more than in  FIG. 70 . 
     Next, referring to  FIG. 72 , the expression unit  4110  may further ascend. 
     At this time, the driving control unit  4142  moves within the guide groove  4135 , and thus the driving control unit  4142  may be disposed in the second groove  4135   b  of the guide groove  4135 . 
     Through the driving of the driving unit  4140 , the expression unit  4110  may ascend more than in  FIG. 70 . Also, according to the shape of the driving unit  4140 , the expression unit  4110  may be at the highest point. 
     The state of the expression unit  4110  may be maintained even when the input pen is removed, and a user may sense a protruding state of the expression unit  4110  tactilely or visually. 
     Next, referring to  FIG. 73 , the driving control unit  4142  may descend more than in  FIG. 72  and may be disposed in the second groove  4135   b  of the guide groove  4135 . 
     Through the driving of the driving unit  4140 , the expression unit  4110  may be at the same position as in  FIG. 70 , e.g., the lowest point. 
     The descending movement may be performed by initialization using a reset member (not shown). For example, the descending movement may be performed by a magnetic field between the reset member and the magnetic unit  4150  of the driving unit  4140 . 
     The driving unit of the output unit of the present embodiment may easily move in the first direction, for example, rise by the magnetic field generated between the input pen and the input pen, and may descend through an initialization process through the reset member. 
     For example, when an attractive force is generated between the driving unit and an input pen according to the polarity of a magnetic unit disposed inside the driving unit, the driving unit may ascend while performing an angular movement or a rotational movement. At this time, the driving control unit disposed in the driving unit may facilitate ascending and descending according to the shape of a guide groove, and, according to an optional embodiment, the driving unit may move along a gentle path of the driving control unit according to a curved shape or an arc-like shape of a connection groove of the guide groove. 
     Therefore, ascending and descending of the driving unit become smooth, natural, and precise movements, thereby reducing the irregular intermittentness of ascending and descending of the expression unit and facilitating the control of flexible and precise movements. 
     The expression unit may ascend and descend, thereby facilitating implementation of an ON state or an OFF state of an output unit. 
     Also, according to an optional embodiment, the driving control unit may be disposed on the top surface of an intermediate portion after ascending, and, in this case, the driving unit may maintain the state even when a force such as a magnetic field is not applied to the driving unit. 
     Also, an initialization may be easily performed by making the driving unit to descend by using a reset member. Therefore, the expression unit may ascend and descend, thereby facilitating implementation of an ON state or an OFF state of an output unit. 
     Therefore, it is possible to easily switch and maintain ON and OFF states of an information output device, reduce power consumption for movement of an expression unit, and improve the overall energy efficiency of the information output device. 
     According to an optional embodiment, a magnetic unit provided in a driving unit may be disposed to overlap a driving control unit. For example, the center of the magnetic unit may overlap the driving control unit. 
     Therefore, it is possible to reduce a change in the position of a magnetic unit during the movement of a driving unit based on a driving control unit, reduce the non-uniformity of an effect of a magnetic field on the magnetic unit, and facilitate precise control of a movement of the driving unit. 
       FIG. 74  is a schematic perspective view of an output unit according to another embodiment of the present disclosure,  FIG. 75  is a schematic front view of the output unit viewed from one direction of  FIG. 74 ,  FIG. 76  is a diagram for describing a driving unit of  FIG. 74 , and  FIG. 77  is a cross-sectional view taken along a line XI-XI of  FIG. 76 . 
     Referring to  FIGS. 74 to 77 , the output unit IU 8  may include a coil  4220 , a base unit  4230 , a driving unit  4240 , and an expression unit  4210 . 
     Also, the base unit  4230  may include one or more guide grooves  4235 . 
     The expression unit  4210  may move according to the movement of the driving unit  4240  to be described later and may move upward and downward at least in the lengthwise direction of the expression unit  4210 . Therefore, the expression unit  4210  may be moved to protrude in one direction, and a user may sense the movement of the expression unit  4210  tactilely or visually. 
     The expression unit  4210  may include an expression surface  4211  and a support surface  4212 . 
     The support surface  4212  is a surface from among areas of the expression unit  4210  facing the driving unit  4240  and may constitute a lower area of the expression unit  4210  and contact the driving unit  4240 . The driving unit  4240  may transmit a force to the expression unit  4210  through the support surface  4212 . For example, a driving surface  4240   a  of the driving unit  4240  may contact the support surface  4212  and allow the support surface  4212  to move in a first direction, that is, the Z-axis direction in  FIG. 74 . 
     According to an optional embodiment, the support surface  4212  may include a curved surface, thereby implementing flexible driving force transmission through the driving unit  4240 . 
     According to an optional embodiment, the support surface  4212  may have a convex shape having a width smaller than that of a main body area of the expression unit  4210  and, according to an optional embodiment, may include a portion of the sphere. 
     The expression surface  4211  is an area of the outermost (e.g., the topmost) surface from among areas of the expression unit  4210  and may include an area to be recognized by a user. 
     For example, the entire area of the expression unit  4210  may be recognized by a user or only the expression surface  4211  may be recognized. 
     For example, a user may sense the movement of the expression unit  4210  through contact with the expression surface  4211 , and the user may easily sense the movement of the expression unit  4210  through visual sensing of the expression surface  4211 . 
     According to an optional embodiment, the expression surface  4211  may include a curved surface. 
     The expression unit  4210  may have various shapes. The expression unit  4210  may include a pillar-like area. For example, the expression unit  4210  may include an area having a shape similar to that of a cylinder. 
     In this case, a protruding area of the expression unit  4210  may have a curved surface and may also have rounded corners. 
     The expression unit  4210  may include various materials and may include an insulating material as a light and durable material. For example, the expression unit  4210  may include a resin-based organic material. According to another embodiment, the expression unit  4210  may include an inorganic material, such as a ceramic material. 
     Also, according to another selective embodiment, the expression unit  4210  may include a material like a metal or glass. 
     According to an optional embodiment, a support unit  4270  may be further disposed, and, for example, the support unit  4270  may include an extension member  4271 . 
     According to an optional embodiment, one end of the extension member  4271  may be extended to overlap or support one area of the driving unit  4240  to be described later. 
     According to an optional embodiment, the support unit  4270  may include a body member  4272 , and the extension member  4271  may be connected to the body member  4272 . 
     As a specific example, the extension member  4271  may have a shape extending from the body member  4272  in a direction close to the expression unit  4210 . 
     According to an optional embodiment, the body member  4272  and the extension member  4271  of the support unit  4270  may be integrated with each other. 
     Although not shown, according to an optional embodiment, a base (not shown) may be further included to support the body member  4272 , and the body member  4272  may be disposed on the base (not shown). 
     The base unit  4230  may include a first accommodation unit  4231 , a second accommodation unit  4232 , and the guide groove  4235 . 
     The first accommodation unit  4231  and the second accommodation unit  4232  may be arranged adjacent to each other and may not overlap each other. 
     According to an optional embodiment, the first accommodation unit  4231  and the second accommodation unit  4232  may be spaced apart from each other. 
     According to another selective embodiment, the first accommodation unit  4231  and the second accommodation unit  4232  may be connected through a through hole. 
     According to an optional embodiment, the above-stated support unit  4270  may be disposed in the first accommodation unit  4231 . Although not shown, according to another additional embodiment, an area of the support unit  4270 , e.g., an area of the extension member  4271 , may be extended and disposed in the second accommodation unit  4232  through the through hole. 
     The guide groove  4235  may be formed in the second accommodation unit  4232 . For example, the guide grooves  4235  may be formed on inner side surfaces of the second accommodation unit  4232  of the base unit  4230  facing each other. According to another selective embodiment, the guide groove  4235  may be formed on only one of the inner side surfaces. 
     The guide groove  4235  may have a shape of a through-hole. According to another embodiment, the guide groove  4235  may have a shape of a groove that is not exposed to the outside of the base unit  4230 . 
     The guide groove  4235  is identical to that in the above-stated embodiment described above with reference to  FIG. 67 , and thus detailed descriptions thereof will be omitted. 
     Also, since an intermediate portion  4237  and the top surface of the intermediate portion  4237  are identical to those in the above-stated embodiment described above, detailed descriptions thereof will be omitted. 
     The base unit  4230  may have an elongated shape to accommodate the driving unit  4240  and may be formed to completely surround the driving unit  4240 . 
     According to an optional embodiment, the base unit  4230  may include a boundary  4233  between the first accommodation unit  4231  and the second accommodation unit  4232 . 
     The first accommodation unit  4231  and the second accommodation unit  4232  may be separated by the boundary  4233 . 
     Although not shown, according to an optional embodiment, a through hole may be formed in the boundary  4233 , and an area of the support unit  4270  may be disposed to extend and pass therethrough. 
     Also, the base unit  4230  may include an inlet  4230   a , and the inlet  4230   a  may be connected to the second accommodation unit  4232 . The expression unit  4210  may move, such that the length of a portion thereof protruding out of the base unit  4230  through the inlet  4230   a  varies. 
     According to an optional embodiment, the base unit  4230  may include an open area  4239 . In detail, the open area  4239  may be formed to be connected to the first accommodation unit  4231 . 
     The open area  4239  may facilitate placement, replacement, or repair of the support unit  4270 . 
     According to an optional embodiment, a window  4232 H connected to one area of the second accommodation unit  4232  of the base unit  4230  may be formed. Even in a state in which the expression unit  4210  is not removed, the state of the second accommodation unit  4232 , e.g., the state or driving of the driving unit  4240 , may be checked or inspected through the window  4232 H. 
     According to an additional embodiment, the width and the height of the window  4232 H may be equal to or greater than the width and the height of the driving unit  4240  in at least one direction. Therefore, when occasions demand, the driving unit  4240  may be easily discharged and put in through the window  4232 H and may be easily replaced, repaired, and inspected. 
     The driving unit  4240  may be disposed at the base unit  4230 . The driving unit  4240  may be disposed in the second accommodation unit  4232 . 
     The driving unit  4240  may be driven by a magnetic field generated between the driving unit  4240  and an input pen (or a reset member) and perform an angular movement or a rotational movement. Through the driving unit  4240 , the expression unit  4210  may move up and down, e.g., in one direction toward a coil and in a direction opposite thereto. 
     According to an optional embodiment, a magnetic unit  4250  may be disposed in the driving unit  4240 , for example, in the inner space of the driving unit  4240 . For example, the magnetic unit  4250  may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  4250  may include a first area  4251  (e.g., an N pole or an S pole) and a second area  4252  (e.g., an S pole or an N pole) having different polarities, and the first area  4251  and the second area  4252  having different polarities may be arranged in a direction toward the expression unit  4210  during a rotation of the driving unit  4240 , e.g., the Z-axis direction. 
     According to an optional embodiment, when the driving unit  4240  is at the lowest point, the center axis of the magnetic unit  4250  may not coaxial with the center axis of the driving unit  4240  and may be misaligned. Therefore, when the driving unit  4240  is driven, a torque may be generated at the driving unit  4240 , thereby facilitating a rotational movement or an angular movement of the driving unit  4240 . 
     According to an optional embodiment, the outer surface of the driving unit  4240  may include a driving surface, and at least an area thereof (e.g., a corner area) may include a curved surface. Also, the outer surface of the driving unit  4240  may be formed to support the expression unit  4210 , thereby providing a driving force for the vertical movement of the expression unit  4210 . 
     According to an optional embodiment, the driving unit  4240  may have a shape similar to a cuboid and may have a shape with rounded corners. 
     Also, according to an optional embodiment, one or more grooves may be formed on one surface of the driving unit  4240 . For example, the one or more grooves may include two or more grooves. At least one groove IT may include a connection groove IT, and the connection groove IT may be connected to an area where the magnetic unit  4250  is disposed, and thus the magnetic unit  4250  may be partially exposed through the connection groove IT. 
     In addition, according to an optional embodiment, the connection groove IT may have a width equal to or greater than the width of the magnetic unit  4250  in one direction, and thus, when desired, the magnetic unit  4250  may be introduced or removed through the connection groove IT. 
     The driving unit  4240  may include a driving control unit  4242 . Although not specifically shown, according to an optional embodiment, driving control units  4242  may be arranged on both side surfaces of the driving unit  4240 . 
     The driving position of the driving unit  4240  may be controlled through the driving control unit  4242 . For example, when the driving unit  4240  moves, the driving unit  4240  may move while the driving control unit  4242  is being disposed in the guide groove  4235 . 
     According to an optional embodiment, the driving control unit  4242  may perform a movement similar to the shape of the guide groove  4235 , e.g., the shape of the alphabet “U”. 
     The driving control unit  4242  may have a protruding shape. For example, the driving control unit  4242  may have a shape protruding from a side surface of the driving unit  4240 , and the driving control unit  4242  may be disposed in the guide groove  4235 . 
     According to an optional embodiment, the driving control unit  4242  may include an outer surface  4242   a  and an inner surface  4242   b.    
     The outer surface  4242   a  is a surface facing a surface close to the outer surface of the guide groove  4235 , e.g., the outer surface of the base unit  4230 , when the driving unit  4240  is disposed in the guide groove  4235 . 
     The inner surface  4242   b  is a surface facing an inner surface of the guide groove  4235 , e.g., the intermediate portion  4237 , when the driving unit  4240  is disposed in the guide groove  4235 . 
     According to an optional embodiment, the outer surface  4242   a  may include a curved surface. Therefore, when the driving unit  4240  moves in the guide groove  4235 , the outer surface  4242   a  may stably move in a first groove  4235   a , a second groove  4235   b , and a connection groove  4235   c . According to an optional embodiment, when the connection groove  4235   c  includes a curved surface or at least one area of an arc, friction with the outer surface  4242   a  may be reduced, thereby facilitating smooth movement of the driving unit  4240  and improving efficiency of the movement of the driving unit  4240 . 
     According to an optional embodiment, at least one area of the inner surface  4242   b  may include a flat surface. Therefore, the driving unit  4240  may stably move. For example, when the driving control unit  4242  ascends and is disposed on a top surface  4238  of the intermediate portion  4237 , the driving control unit  4242  may be stably placed on the top surface  4238  of the intermediate portion  4237 . 
     A driving unit of an output unit of the present embodiment may easily move in a first direction (e.g., ascend) by a magnetic field generated between the driving unit and an input pen. 
     The expression unit may ascend and descend, thereby facilitating implementation of an ON state or an OFF state of an output unit. 
       FIGS. 78 and 79  are schematic front views of the operation of an output unit according to another embodiment of the present disclosure, and  FIG. 80  is a side view viewed in a direction A of  FIG. 78 . 
     The output unit IU 8  of the present embodiment may include a base unit (not shown), a driving unit  4340 , and an expression unit (not shown). 
     For convenience of explanation, descriptions below will focus on differences from the above-described embodiment. 
     Also, for convenience of explanation, the base unit and the expression unit are not shown in the drawings. 
     A support unit  4370  may include an extension member  4371 , and one end of the extension member  4371  may be extended to overlap or support one area of the driving unit  4340  to be described later. 
     According to an optional embodiment, the support unit  4370  may include a body member  4372 , and the extension member  4371  may be connected to the body member  4372 . 
     A magnetic unit  4350  may be disposed in the inner space of the driving unit  4340 . For example, the magnetic unit  4350  may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  4350  may include a first area  4351  (e.g., an N pole or an S pole) and a second area  4352  (e.g., an S pole or an N pole) having different polarities, and the first area  4351  and the second area  4352  having different polarities may be arranged in a direction toward an expression unit  4310  during a rotation of the driving unit  4340 , e.g., the Z-axis direction. 
     The driving unit  4340  may include a first driving member  4343  and a second driving member  4344  and may include the separation space SA therebetween. 
     External surfaces of the first driving member  4343  and the second driving member  4344  may each include a driving surface on at least one surface to support the expression unit  4310  during a movement of the driving unit  4340 , thereby providing a driving force to the expression unit  4310 . 
     According to an optional embodiment, at least one area of the outer surfaces of the first driving member  4343  and the second driving member  4344  may include a curved surface. For example, the first driving member  4343  and the second driving member  4344  may have rounded corners. 
     Therefore, ascending and descending of the expression unit may be gently switched during a rotation or an angular movement of the first driving member  4343  and the second driving member  4344 , thereby allowing the expression unit to efficiently perform a continuous and smooth movement. 
     Although not shown, driving control units (not shown) may be arranged on at least one side surfaces of the first driving member  4343  and the second driving member  4344 , e.g., surfaces of the first driving member  4343  and the second driving member  4344  opposite to side surfaces of the first driving member  4343  and the second driving member  4344  facing each other. 
     According to an optional embodiment, the driving control unit (not shown) may have a protruding shape and may have the same structure as described in the above-described embodiment. 
     Also, according to another selective embodiment, a drive control unit (not shown) may have a protruding shape similar to a circle (that is, a cylindrical shape) instead of the shape of the above-described embodiment similar to a semicircle. In this case, a guide groove (not shown) may have a groove-like shape formed in one direction, that is, the Z-axis direction. 
     A driving proximity portion  4345  may be disposed in the separation space SA between the first driving member  4343  and the second driving member  4344 . 
     According to an optional embodiment, the driving proximity portion  4345  may be disposed at a position overlapping the magnetic unit  4350 . 
     According to an optional embodiment, the driving proximity portion  4345  may overlap the center axis of the extension member  4371 . 
     The driving proximity portion  4345  may move and be supported together with the driving unit  4340  when the driving unit  4340  performs a rotational movement or an angular movement. For example, the driving proximity portion  4345  may be supported by one end of the extension member  4371  of the support unit  4370 . According to another example, a base unit (not shown) may include an area extending in a direction toward the extension member  4371 , and the area may support the driving proximity portion  4345 . 
     The driving proximity portion  4345  is formed to have a smaller width than the first driving member  4343  and the second driving member  4344 , and distances from the outer surface of the driving proximity portion  4345  to the first driving member  4343  and the second driving member  4344  may vary according to areas. 
     Therefore, the height of the driving unit  4340  may vary according to an angular movement or a rotational movement of the driving proximity portion  4345 . 
     In other words, as compared to  FIG. 78 ,  FIG. 79  shows that the driving proximity portion  4345   79  is rotated, for example, 180 degrees, and accordingly, the driving unit  4340  performed a rotational movement and an ascending movement. 
     In an information output unit of the present embodiment, a driving unit moves by a magnetic field generated between the driving unit and an input pen. Therefore, an expression unit may also easily move in a first direction (e.g., ascend) and may move and rotate while maintaining a certain area through a driving control unit. 
     Also, in this case, instead of an U-shaped guide groove, only a groove extending in one direction may be included, and, in this case, the groove may overlap the center axis of an extension member. 
       FIG. 81  is a schematic front view of an output unit according to another embodiment of the present disclosure,  FIG. 82  is a diagram for describing a driving unit of  FIG. 81 , and  FIG. 83  is a diagram showing an optional embodiment of the driving unit of  FIG. 81 . 
       FIG. 84  is a diagram for describing a guide groove of  FIG. 81 . 
       FIGS. 85 and 86  are diagrams for describing the operation of an information output device of  FIG. 81 . 
     The output unit IU 8  may include a base unit  4430 , a driving unit  4440 , and an expression unit  4410 . 
     Also, the base unit  4430  may include one or more guide grooves  4435 . 
     The expression unit  4410  may move according to the movement of the driving unit  4440  to be described later and may move upward and downward at least in the lengthwise direction of the expression unit  4410 . Therefore, the expression unit  4410  may be moved to protrude in one direction, and a user may sense the movement of the expression unit  4410  tactilely or visually. 
     The expression unit  4410  may include an expression surface  4411  and a support surface  4412 . 
     The support surface  4412  is a surface from among areas of the expression unit  4410  facing the driving unit  4440  and may constitute a lower area of the expression unit  4410  and contact the driving unit  4440 . The driving unit  4440  may transmit a force to the expression unit  4410  through the support surface  4412 . For example, a driving surface  4440   a  of the driving unit  4440  may contact the support surface  4412  and allow the support surface  4412  to move in a first direction, that is, the Z-axis direction in  FIG. 81 . 
     According to an optional embodiment, the support surface  4412  may include a curved surface, thereby implementing flexible driving force transmission through the driving unit  4440 . 
     For example, the entire area of the expression unit  4410  may be recognized by a user or only the expression surface  4411  may be recognized. For example, a user may sense the movement of the expression unit  4410  through contact with the expression surface  4411 , and the user may easily sense the movement of the expression unit  4410  through visual sensing of the expression surface  4411 . 
     According to an optional embodiment, the expression surface  4411  may include a curved surface. 
     The expression unit  4410  may have various shapes. The expression unit  4410  may include a pillar-like area. For example, the expression unit  4410  may include an area having a shape similar to that of a cylinder. 
     In this case, a protruding area of the expression unit  4410  may have a curved surface and may also have rounded corners. 
     The expression unit  4410  may include various materials and may include an insulating material as a light and durable material. For example, the expression unit  4410  may include a resin-based organic material. According to another embodiment, the expression unit  4410  may include an inorganic material, such as a ceramic material. 
     Also, according to another selective embodiment, the expression unit  4410  may include a material like a metal or glass. 
     According to an optional embodiment, one end of the extension member  4471  may be extended to overlap or support one area of the driving unit  4440  to be described later. 
     According to an optional embodiment, a support unit  4470  may include a body member  4472 , and the extension member  4471  may be connected to the body member  4472 . 
     As a specific example, the extension member  4471  may have a shape extending from the body member  4472  in a direction close to the expression unit  4410 . 
     According to an optional embodiment, the body member  4472  and the extension member  4471  of the support unit  4470  may be integrated with each other. 
     Although not shown, according to an optional embodiment, a base (not shown) may be further included to support the body member  4472 , and the body member  4472  may be disposed on the base (not shown). 
     The base unit  4430  may include a first accommodation unit  4431 , a second accommodation unit  4432 , and the guide groove  4435 . 
     The first accommodation unit  4431  and the second accommodation unit  4432  may be arranged adjacent to each other and may not overlap each other. 
     According to an optional embodiment, the first accommodation unit  4431  and the second accommodation unit  4432  may be spaced apart from each other. 
     According to another selective embodiment, the first accommodation unit  4431  and the second accommodation unit  4432  may be connected through a through hole. 
     According to an optional embodiment, the above-stated support unit  4470  may be disposed in the first accommodation unit  4431 . Although not shown, according to another additional embodiment, an area of the support unit  4470 , e.g., an area of the extension member  4471 , may be extended and disposed in the second accommodation unit  4432  through the through hole. 
     The guide groove  4435  may be formed in the second accommodation unit  4432 . For example, the guide grooves  4435  may be formed on inner side surfaces of the second accommodation unit  4432  of the base unit  4430  facing each other. According to another selective embodiment, the guide groove  4435  may be formed on only one of the inner side surfaces. 
     The guide groove  4435  may have a shape of a through-hole. According to another embodiment, the guide groove  4435  may have a shape of a groove that is not exposed to the outside of the base unit  4430 . 
     Referring to  FIG. 84 , the guide groove  4435  may include a first groove  4435   a , a second groove  4435   b , and a connection groove  4435   c.    
     The first groove  4435   a  and the second groove  4435   b  may be spaced apart from each other, and, according to an optional embodiment, an intermediate portion  4437  may be formed between the first groove  4435   a  and the second groove  4435   b.    
     The guide groove  4435  is identical to that in the above-stated embodiment described above with reference to  FIG. 20 , and thus detailed descriptions thereof will be omitted. 
     The base unit  4430  may have an elongated shape to accommodate the driving unit  4440  and may be formed to completely surround the driving unit  4440 . 
     According to an optional embodiment, the base unit  4430  may include a boundary  4433  between the first accommodation unit  4431  and the second accommodation unit  4432 . 
     The first accommodation unit  4431  and the second accommodation unit  4432  may be separated by the boundary  4433 . 
     Although not shown, according to an optional embodiment, a through hole may be formed in the boundary  4433 , and an area of the extension member  4471  of the support unit  4470  may be disposed to extend and pass therethrough. 
     Also, the base unit  4430  may include an inlet  4430   a , and the inlet  4430   a  may be connected to the second accommodation unit  4432 . The expression unit  4410  may move, such that the length of a portion thereof protruding out of the base unit  4430  through the inlet  4430   a  varies. 
     According to an optional embodiment, the base unit  4430  may include an open area  4439 . In detail, the open area  4439  may be formed to be connected to the first accommodation unit  4431 . 
     The open area  4439  may facilitate placement, replacement, or repair of the support unit  4470 . 
     The driving unit  4440  may be disposed at the base unit  4430 . The driving unit  4440  may be disposed in the second accommodation unit  4432 . 
     The driving unit  4440  may be driven by a magnetic field generated between the driving unit  4440  and an input pen (or a reset member) and perform an angular movement or a rotational movement. The expression unit  4410  may move up and down, e.g., ascend and descend, by the driving unit  4440 . 
     A magnetic unit  4450  may be disposed in the inner space of the driving unit  4440 . For example, the magnetic unit  4450  may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  4450  may include a first area  4451  (e.g., an N pole or an S pole) and a second area  4452  (e.g., an S pole or an N pole) having different polarities, and the first area  4451  and the second area  4452  having different polarities may be arranged in a direction toward an expression unit  4410  during a rotation of the driving unit  4440 , e.g., the Z-axis direction. 
     The driving unit  4440  may include a driving surface  4441   a  on at least the outer surface, and the driving surface  4441   a  may be formed to support the expression unit  4410 , thereby providing a driving force for the vertical movement of the expression unit  4410 . 
     According to an optional embodiment, the driving surface  4441   a  of the driving unit  4440  may include a curved surface as the outer surface. According to a more specific embodiment, the driving surface  4441   a  of the driving unit  4440  may include a boundary line having a circle-like shape. 
     The driving unit  4440  may include a driving control unit  4442 . Although not specifically shown, according to an optional embodiment, driving control units  4442  may be arranged on both side surfaces of the driving unit  4440 . 
     The driving position of the driving unit  4440  may be controlled through the driving control unit  4442 . For example, when the driving unit  4440  moves, the driving unit  4440  may move while the driving control unit  4442  is being disposed in the guide groove  4435 . 
     The driving control unit  4442  may have a protruding shape. For example, the driving control unit  4442  may have a shape protruding from a side surface of the driving unit  4440 , and the driving control unit  4442  may be disposed in the guide groove  4435 . 
     According to an optional embodiment, the driving control unit  4442  may include an outer surface  4442   a  and an inner surface  4442   b.    
     The present embodiment may include a driving proximity portion  4445  formed in one area of the driving unit  4440 . 
     According to an optional embodiment, the driving proximity portion  4445  may be disposed at a position overlapping the magnetic unit  4450 . 
     The driving proximity portion  4445  may move and be supported together with the driving unit  4440  when the driving unit  4440  performs a rotational movement or an angular movement. For example, the driving proximity portion  4445  may be supported by one end of the extension member  4471  of the support unit  4470 . According to another example, the base unit  4430  may include an area extending in a direction toward the extension member  4471 , and the area may support the driving proximity portion  4445 . 
     The driving proximity portion  4445  may include a first area  4446 , a second area  4448 , and a connection area  4447  having different distances from the driving surface  4441   a  of the driving unit  4440 , and, as the first area  4446 , the second area  4448 , and the connection area  4447  of the driving proximity portion  4445  are supported by the extension member  4471  of the support unit  4470 , the height of the driving unit  4440  may change. 
       FIG. 83  is a diagram showing one of selective embodiments of the driving unit of  FIG. 81 . 
     A drive unit  4440 ′ may include a magnetic unit  4450 ′ disposed in the inner space thereof. For example, the magnetic unit  4450 ′ may include a magnetic body, such as a permanent magnet. 
     The magnetic unit  4450 ′ may include a first area (e.g., an N pole or an S pole′) and a second area (e.g., an S pole or an N pole′) having different polarities from each other. 
     The driving unit  4440 ′ may include a driving surface  4441   a ′ on at least the outer surface, and the driving surface  4441   a ′ may be formed to support an expression unit  4410 ′, thereby providing a driving force for the vertical movement of the expression unit  4410 ′. 
     According to an optional embodiment, the driving surface  4441   a ′ of the driving unit  4440 ′ may include a curved surface as the outer surface. According to a more specific embodiment, the driving surface  4441   a ′ of the driving unit  4440 ′ may include a boundary line having a circle-like shape. 
     The driving unit  4440 ′ may include a driving control unit  4442 ′. The driving control unit  4442  may include the outer surface  4442   a  and the inner surface  4442   b , which may be the same or similar as those described in the above-described embodiments, and thus a detailed descriptions thereof will be omitted. 
     The driving unit  4440 ′ may include a first driving member  4443 ′ and a second driving member  4444 ′ and may include a separation space SA′ therebetween. 
     External surfaces of the first driving member  4443 ′ and the second driving member  4444 ′ may each include the driving surface  4441   a ′ on at least one surface to support the expression unit  4410 ′ during a movement of the driving unit  4440 ′, thereby providing a driving force to the expression unit  4410 ′. 
     According to an optional embodiment, outer surfaces of the first driving member  4443 ′ and the second driving member  4444 ′ may include curved surfaces. For example, the first driving member  4443 ′ and the second driving member  4444 ′ may each have a shape similar to that of a rotating body and may each have a disk-like shape. 
     Therefore, a natural driving force may be provided to a support surface  4412 ′ of the expression unit  4410 ′ during a rotation or an angular movement of the first driving member  4443 ′ and the second driving member  4444 ′, thereby allowing the expression unit  4410 ′ to efficiently perform a continuous and smooth movement. 
     Driving control units  4442 ′ may be arranged on at least one side surfaces of the first driving member  4443 ′ and the second driving member  4444 ′, e.g., surfaces of the first driving member  4443 ′ and the second driving member  4444 ′ opposite to side surfaces of the first driving member  4443 ′ and the second driving member  4444 ′ facing each other. 
     A driving proximity portion  4445 ′ may be disposed in the separation space SA′ between the first driving member  4443 ′ and the second driving member  4444 ′. The driving proximity portion  4445 ′ may include a first area  4446 ′, a second area  4448 ′, and a connection area  4447 ′. 
     According to an optional embodiment, the driving proximity portion  4445 ′ may be disposed at a position overlapping the magnetic unit  4450 ′. 
     According to an optional embodiment, the driving proximity portion  4445 ′ may overlap the center axis of the extension member  4471 . 
     The driving proximity portion  4445 ′ may move and be supported together with the driving unit  4440 ′ when the driving unit  4440 ′ performs a rotational movement or an angular movement. For example, the driving proximity portion  4445 ′ may be supported by one end of the extension member  4471  of the support unit  4470 . 
     The driving proximity portion  4445 ′ is formed to have a smaller width than the first driving member  4443 ′ and the second driving member  4444 ′, and distances from the outer surface of the driving proximity portion  4445 ′ to driving surfaces  4441   a ′ of the first driving member  4443 ′ and the second driving member  4444 ′ may vary according to areas. 
     For example, a distance between the first area  4446 ′ and the driving surface  4441   a ′ may be greater than a distance between the second area  4448 ′ and the driving surface  4441   a′.    
     Therefore, the height of the driving unit  4440 ′ may change according to an angular movement or a rotational movement of the driving proximity portion  4445 ′. In this case, a significant change of a distance between the magnetic unit  4450 ′, which overlaps the driving proximity portion  4445 ′ (more particularly, disposed inside the driving proximity portion  4445 ′), and the extension member  4471  may be reduced and the distance may be maintained constant or within a certain range. 
     According to an optional embodiment, the connection area  4447 ′ may be disposed between the first area  4446 ′ and the second area  4448 ′, and the connection area  4447 ′ may include a curved surface. 
     During a rotational movement of the driving unit  4440 ′, the extension member  4471  may support at least one area of the connection area  4447 ′ while supporting the first area  4446 ′ and before supporting the second area  4448 ′, Therefore, the driving unit  4440 ′ may naturally move, and thus the movement of the expression unit  4410  may be precisely controlled. 
       FIGS. 85 and 86  are diagrams for describing the operation of an information output device of  FIG. 81 . 
       FIG. 85  shows that, as compared to  FIG. 81 , the driving unit  4440  ascends, and thus the expression unit  4410  also ascends. 
     For example, the driving unit  4440  may be moved by a magnetic field generated between an input pen and the magnetic unit  4450  of the driving unit  4440  as a user moves the input pen. For example, when an attractive force is applied between the second area  4452  of the magnetic unit  4450  disposed in the driving unit  4440  and the input pen, the driving unit  4440  may ascend by the attractive force applied to the magnetic unit  4450 . For example, the driving unit  4440  may ascend by the height H 1 . 
     Next, referring to  FIG. 86 , initialization may be performed through a reset member (not shown), and thus the expression unit  4410  may descend. 
     At this time, the driving control unit  4442  moves within the guide groove  4435 , and thus the driving control unit  4442  may pass a top surface  4438  of the intermediate portion  4437  and, in some cases, may be maintained on the top surface  4438 . 
     The driving control unit  4442  may pass the top surface  4438  and may be disposed in the second groove  4435   b  in the guide groove  4435 . 
     In other words,  FIG. 86  shows that the driving unit  4440  descends and the driving control unit  4442  is disposed at the lowest point of the second groove  4435   b  of the guide groove  4435 . 
     A driving unit of an output unit of the present embodiment may move at least in a first direction or in a direction opposite thereto, and, according to the movement of the driving unit, an expression unit may also move in the first direction or in the direction opposite thereto and output various information that may be sensed by a user. 
     The expression unit may ascend and descend, thereby facilitating implementation of an ON state or an OFF state of an information output device. 
     A driving unit of an output unit of the present embodiment includes a driving proximity portion, the driving proximity portion may be supported during a rotational movement or an angular movement of the driving unit, and the driving unit may ascend or descend as a distance between the driving proximity portion and a driving surface of the driving unit is different in each area. 
     Therefore, it is possible to reduce a change in a vertical moving distance of a magnetic unit, thereby reducing the non-uniformity of a driving force of the driving unit. Therefore, non-uniform ascending and descending characteristics of an expression unit may be reduced. 
     Also, according to an optional embodiment, a driving surface of the driving unit may have a curved surface (more particularly, a planar shape similar to a circle), and thus movement changes for the expression unit may be controlled precisely. 
       FIG. 87  is a schematic perspective view of the operation of an output unit according to another embodiment of the present disclosure, and  FIG. 88  is a side view viewed in one direction of  FIG. 87 . 
     Referring to  FIGS. 87 and 88 , the output unit IU 8  according to the present embodiment may include a base unit  4530 , a driving unit  4540 , and an expression unit  4510 . 
     Also, the base unit  4530  may include one or more guide grooves  4535 . 
     The expression unit  4510  may move according to the movement of the driving unit  4540  to be described later and may move upward and downward at least in the lengthwise direction of the expression unit  4510 . 
     Therefore, the expression unit  4510  may be moved to protrude in one direction, and a user may sense the movement of the expression unit  4510  tactilely or visually. 
     The expression unit  4510  may include an expression surface  4511  and a support surface  4512 . 
     The support surface  4512  is a surface from among areas of the expression unit  4510  facing the driving unit  4540  and may constitute a lower area of the expression unit  4510  and contact the driving unit  4540 . The driving unit  4540  may transmit a force to the expression unit  4510  through the support surface  4512 . 
     According to an optional embodiment, the support surface  4512  may include a curved surface, thereby implementing flexible driving force transmission through the driving unit  4540 . 
     The expression surface  4511  is the outermost (e.g., the topmost) surface from among areas of the expression unit  4510  and may include an area to be recognized by a user. 
     For example, the entire area of the expression unit  4510  may be recognized by a user or only the expression surface  4511  may be recognized. For example, a user may sense the movement of the expression unit  4510  through contact with the expression surface  4511 , and the user may easily sense the movement of the expression unit  4510  through visual sensing of the expression surface  4511 . 
     According to an optional embodiment, the expression surface  4511  may include a curved surface. 
     The expression unit  4510  may have various shapes. The expression unit  4510  may include a pillar-like area. For example, the expression unit  4510  may include an area having a shape similar to that of a cylinder. 
     In this case, a protruding area of the expression unit  4510  may have a curved surface and may also have rounded corners. 
     The expression unit  4510  may include various materials and may include an insulating material as a light and durable material. For example, the expression unit  4510  may include a resin-based organic material. According to another embodiment, the expression unit  4510  may include an inorganic material, such as a ceramic material. 
     Also, according to another selective embodiment, the expression unit  4510  may include a material like a metal or glass. 
     According to an optional embodiment, one end of the extension member  4571  may be extended to overlap or support one area of the driving unit  4540 . 
     According to an optional embodiment, a support unit  4570  may include a body member  4572 , and an extension member  4571  may be connected to the body member  4572 . 
     As a specific example, the extension member  4571  may have a shape extending from the body member  4572  in a direction close to the expression unit  4510 . 
     According to an optional embodiment, the body member  4572  and the extension member  4571  of a support unit  4570  may be integrated with each other. 
     Although not shown, according to an optional embodiment, a base (not shown) may be further included to support the body member  4572 , and the body member  4572  may be disposed on the base (not shown). 
     The base unit  4530  may include, for example, a first accommodation unit  4531 , a second accommodation unit  4532 , and a guide groove  4535 . 
     The first accommodation unit  4531  and the second accommodation unit  4532  may be arranged adjacent to each other and may not overlap each other. 
     According to an optional embodiment, the first accommodation unit  4531  and the second accommodation unit  4532  may be spaced apart from each other. 
     According to another selective embodiment, the first accommodation unit  4531  and the second accommodation unit  4532  may be connected through a through hole  4530 H. 
     According to an optional embodiment, the above-stated support unit  4570  may be disposed in the first accommodation unit  4531 . According to an additional embodiment, an area of the support unit  4570 , e.g., an area of the extension member  4571 , may be extended and disposed in the second accommodation unit  4532  through the through hole  4530 H. 
     The guide groove  4535  may be formed in the second accommodation unit  4532 . For example, the guide grooves  4535  may be formed on inner side surfaces of the second accommodation unit  4532  of the base unit  4530  facing each other. According to another selective embodiment, the guide groove  4535  may be formed on only one of the inner side surfaces. 
     The guide groove  4535  may have a shape of a through-hole. According to another embodiment, the guide groove  4535  may have a shape of a groove that is not exposed to the outside of the base unit  4430 . 
     Since the guide groove  4535  is identical to that of the above-described embodiment, detailed descriptions thereof will be omitted. 
     The base unit  4530  may have an elongated shape to accommodate the driving unit  4540  and may be formed to completely surround the driving unit  4540 . 
     According to an optional embodiment, the base unit  4530  may include a boundary  4533  between the first accommodation unit  4531  and the second accommodation unit  4532 . 
     The first accommodation unit  4531  and the second accommodation unit  4532  may be separated by the boundary  4533 . 
     Also, the base unit  4530  may include an inlet  4530   a , and the inlet  4530   a  may be connected to the second accommodation unit  4532 . The expression unit  4510  may move, such that the length of a portion thereof protruding out of the base unit  4530  through the inlet  4530   a  varies. 
     According to an optional embodiment, the base unit  4530  may include an open area  4539 . In detail, the open area  4539  may be formed to be connected to the first accommodation unit  4531 . 
     The open area  4539  may facilitate placement, replacement, or repair of the support unit  4570 . 
     According to an optional embodiment, a window  4532 H connected to one area of the second accommodation unit  4532  of the base unit  4530  may be formed. Even in a state in which the expression unit  4510  is not removed, the state of the second accommodation unit  4532 , e.g., the state or driving of the driving unit  4540 , may be checked or inspected through the window  4532 H. 
     According to an additional embodiment, the width and the height of the window  4532 H may be equal to or greater than the width and the height of the driving unit  4540  in at least one direction. Therefore, when occasions demand, the driving unit  4540  may be easily discharged and put in through the window  4532 H and may be easily replaced, repaired, and inspected. 
     The driving unit  4540  may be disposed at the base unit  4530 . The driving unit  4540  may be disposed in the second accommodation unit  4532 . 
     The driving unit  4540  may be driven by a magnetic field generated between the driving unit  4540  and an input pen (or a reset member) and perform an angular movement or a rotational movement. The expression unit  4510  may move up and down by the driving unit  4540 . 
     A magnetic unit  4550  may be disposed in an inner space of the driving unit  4540 . For example, the magnetic unit  4550  may include a magnetic body, e.g., a permanent magnet. 
     The magnetic unit  4550  may include a first area  4551  (e.g., an N pole or an S pole) and a second area  4552  (e.g., an S pole or an N pole) having different polarities, and the first area  4551  and the second area  4552  having different polarities may be arranged in a direction toward an expression unit  4510  during a rotation of the driving unit  4540 , e.g., the Z-axis direction. 
     The driving unit  4440  may include a driving surface on at least the outer surface, and the driving surface may be formed to support the support surface  4512  of the expression unit  4510 , thereby providing a driving force for the vertical movement of the expression unit  4510 . 
     The driving unit  4540  may include a driving control unit  4542 . 
     The present embodiment may include a driving proximity portion  4545  formed in one area of the driving unit  4540 . 
     According to an optional embodiment, the driving proximity portion  4545  may be disposed at a position overlapping the magnetic unit  4550 . 
     The driving unit  4540  may include a first driving member  4543  and a second driving member  4544  and may include the separation space SA therebetween. 
     A driving proximity portion  4545  may be disposed in the separation space SA between the first driving member  4543  and the second driving member  4544 . 
     Since the driving unit  4540  and the driving control unit  4542  are the same as or similar to those of the above-described embodiments, detailed descriptions thereof will be omitted. 
     The second accommodation unit  4532  of the base unit  4530  may include a first groove  4532   c  and a second groove  4532   d.    
     The first groove  4532   c  and the second groove  4532   d  may extend long. The first driving member  4543  and the second driving member  4544  may be arranged in correspondence to the first groove  4532   c  and the second groove  4532   d , respectively. Therefore, the driving unit  4540  may perform an angular movement, or a rotational movement, or a vertical movement while The first driving member  4543  and the second driving member  4544  of the driving unit  4540  are being arranged in correspondence to the first groove  4532   c  and the second groove  4532   d . Therefore, the driving unit  4540  may stably move, thereby facilitating precise movement control for the expression unit  4510 . 
     According to an optional embodiment, a protrusion may be formed between the first groove  4532   c  and the second groove  4532   d . For example, the through hole  4530 H may be formed in the protrusion. 
     The extension member  4571  of the support unit  4570  may correspond to the through hole  4530 H. At this time, the extension member  4571  may protrude through the through hole  4530 H and protrude more than the protrusion, and, according to an optional embodiment, the extension member  4571  may not protrude more than the protrusion or may protrude to the same height as the protrusion. 
     A driving unit of an output unit of the present embodiment may easily move in a first direction (e.g., ascend) by a magnetic field generated between the driving unit and an input pen and may descend through an initialization process using a reset member. 
     Also, a first groove and a second groove are formed in a second accommodation unit of a base unit in correspondence to one area of a first driving member and a second driving member of the driving unit. Therefore, when a driving unit moves, an abnormal change of the position of the driving unit may be reduced or prevented, thereby securing stable movement of the driving unit and precisely controlling a movement of an expression unit. 
       FIGS. 89 and 90  are diagrams for describing a protruding feedback-based smart tablet and a reset member according to another embodiment of the present disclosure. 
     Referring to  FIG. 89 , a plurality of output units may be provided in the expression area DA of a protruding feedback-based smart tablet  5200 . 
     With respect to the expression area DA, a user may perform an input operation by using an input pen  5100 . 
     Therefore, the plurality of output units in the expression area DA of the protruding feedback-based smart tablet  5200  may protrude. Since detail descriptions thereof are identical to those given above for the above-described embodiments, detailed descriptions thereof will be omitted. 
     Referring to  FIG. 90 , the input pen  5100  may include a magnetic body  5110 . Since the magnetic body  5110  provided in the input pen  5100  is the same as that of the above-described embodiment, detailed descriptions thereof will be omitted. For example, the magnetic body  5110  may generate a magnetic field between the input pen  5100  and a driving unit disposed in one area of an output unit, and, as a specific example, the driving unit of the output unit may protrude by an attractive force. 
     Also, the input pen  5100  may include the reset member IMGU. 
     The reset member IMGU may specifically include a coil member (not shown). For example, the reset member IMGU may have the form of a wound coil that generates a magnetic field when a current is applied thereto. As a specific example, a current may be applied to the coil member provided in the reset member IMGU through a power supply unit (not shown) to generate a magnetic field around the coil member. For example, a magnetic field may be generated between the coil member and a driving unit disposed in one area of an output unit. and, as a specific example, a repulsive force to the driving unit of the output unit may be generated. 
     Therefore, the reset member IMGU may correspond to a plurality of output units of the protruding feedback-based smart tablet  5200  and initialize the plurality of output units at the same time. For example, the reset member IMGU may control protruding output units to descend again to return to a non-protruding state. 
     As a result, since it is not necessary to prepare a space for arranging the reset member IMGU in the protruding feedback-based smart tablet  5200 , the thickness of the protruding feedback-based smart tablet  5200  may be easily reduced. 
     According to an optional embodiment, a button member (not shown) may be formed at the input pen  5100 , and, by applying a current to a coil member provided in the reset member IMGU through a power supply unit (not shown) only when the button member (not shown) is selected (e.g., pressed), an initialization process may be selectively performed. 
       FIG. 91  is a diagram schematically showing a protruding feedback-based smart tablet according to another embodiment of the present disclosure, and  FIG. 92  is an enlarged view of an area of the protruding feedback-based smart tablet of  FIG. 91 . 
       FIG. 93  is a cross-sectional view taken along a line XX-XX of  FIG. 92 . 
     A protruding feedback-based smart tablet  6200  of the present embodiment may include an expression area DA. 
     A user may make various inputs to the expression area DA by using an input pen  6100 . For example, a user may write characters, draw figures, and make inputs in various other forms. 
     The expression area DA of the protruding feedback-based smart tablet  6200  includes a plurality of output units. For example, in  FIG. 92 , nine output units IU 1  to IU 9  are shown. However, it is for merely convenience of explanation, and the number of output units included in the expression area DA of the protruding feedback-based smart tablet  6200  may vary in consideration of the size of the expression area DA, the resolution of an output shape, etc. 
     The protruding feedback-based smart tablet  6200  may include a reset member. For example, reset members may be formed in correspondence to the plurality of output units, respectively, and the reset members may be controlled individually or at once. As a specific example, a current may be applied in correspond to each output unit, and an initialization may be performed by using a magnetic field generated through the applied current. 
     Referring to  FIG. 93 , the output unit IU 8  may include an expression unit  6210 , a moving unit  6230 , a magnetic unit  6240 , a coil  6250 , and a base unit  6260 . 
     Since the expression unit  6210 , the moving unit  6230 , the magnetic unit  6240 , and the base unit  6260  are identical to those described above with reference to  FIGS. 23 and 24 , detailed descriptions thereof will be omitted. 
     For example, the structure of  FIG. 93  may correspond to the structure shown in  FIGS. 23 and 24  to which the coil  6250  is added. 
     The coil  6250  may be disposed to surround the outer circumferential surface of a body area  6261  of the base unit  6260 , and may have, for example, the shape of a wound coil. 
     By applying a current to the coil  6250 , a magnetic field for the magnetic unit  6240  may be generated. For example, an attractive force or a repulsive force may be generated. 
     Therefore, an initialization may be performed through the reset member IMGU as shown in  FIG. 38D . 
     In the present embodiment, since an initialization process is performed by controlling application of a current to a coil, a process using the movement of the reset member IMGU as shown in  FIG. 38D  separately provided is not needed. 
     For example, an initialization process for one expression unit  6210  or all expression units  6210  may be easily performed through a signal for applying a current to the coil  6250 . 
       FIG. 94  is a diagram for explaining an output unit according to another embodiment of the present disclosure. 
     Referring to  FIG. 94 , the output unit IU 8  may include a driving expression unit  7210 , a coil  7220 , and a base unit  7230 . 
     Since the driving expression unit  7210  and the base unit  7230  are identical to those of the above-stated embodiment described above with reference to  FIG. 42 , detailed descriptions thereof will be omitted. 
     For example, the structure of  FIG. 94  may correspond to the structure shown in  FIG. 42  to which the coil  7220  is added. 
     The coil  7220  may be disposed in a second area CA distinguished from the first area MA of the base unit  7230 . For example, the coil  7220  may be disposed in a second accommodation unit  7232  spaced apart and distinguished from a first accommodation unit  7231 . 
     By applying a current to the coil  7220 , a magnetic field for the driving expression unit  7210  may be generated. For example, an attractive force or a repulsive force may be generated. 
     Therefore, an initialization may be performed through the reset member IMGU as shown in  FIG. 44C . 
     In the present embodiment, since an initialization process is performed by controlling application of a current to a coil, a process using the movement of the reset member IMGU as shown in  FIG. 44C  separately provided is not needed. 
     For example, an initialization process for one driving expression unit  7210  or all driving expression units  7210  may be easily performed through a signal for applying a current to the coil  7220 . 
       FIG. 95  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
     Referring to  FIG. 95 , the output unit IU 8  of the present embodiment may include a base unit  8130 , a driving unit  8140 , an expression unit  8110 , and a coil  8120 . 
     Since the base unit  8130 , the driving unit  8140 , and the expression unit  8110  are identical to those of the above-stated embodiment described above with reference to  FIG. 53 , detailed descriptions thereof will be omitted. 
     For example, the structure of  FIG. 95  may correspond to the structure shown in  FIG. 53  to which the coil  8120  is added. 
     The coil  8120  may be disposed in a first accommodation unit  8131  of the base unit  8130 . For example, the coil  8120  may have a shape of a coil would around a support unit  8170  to surround the support unit  8170 . 
     By applying a current to the coil  8120 , a magnetic field for the driving unit  8140  may be generated. For example, an attractive force or a repulsive force may be generated. 
     Therefore, an initialization may be performed through the reset member IMGU as shown in  FIG. 55 . 
     In the present embodiment, since an initialization process is performed by controlling application of a current to a coil, a process using the movement of the reset member IMGU as shown in  FIG. 55  separately provided is not needed. 
     For example, an initialization process for one expression unit  8110  or all expression units  8110  may be easily performed through a signal for applying a current to the coil  8120 . 
       FIG. 96  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
     Referring to  FIG. 96 , the output unit IU 8  of the present embodiment may include a base unit  9130 , a driving unit  9140 , an expression unit  9110 , and a coil  9120 . 
     Since the base unit  9130 , the driving unit  9140 , and the expression unit  9110  are identical to those of the above-stated embodiment described above with reference to  FIG. 65 , detailed descriptions thereof will be omitted. 
     For example, the structure of  FIG. 96  may correspond to the structure shown in  FIG. 65  to which the coil  9120  is added. 
     The coil  9120  may be disposed in a first accommodation unit  9131  of the base unit  9130 . For example, the coil  9120  may have a shape of a coil would around an extension member  9171  of a support unit  9170  to surround the extension member  9171 . 
     By applying a current to the coil  9120 , a magnetic field for the driving unit  9140  may be generated. For example, an attractive force or a repulsive force may be generated. 
     Therefore, an initialization may be performed through the reset member IMGU as shown in  FIG. 71 . 
     In the present embodiment, since an initialization process is performed by controlling application of a current to a coil, a process using the movement of the reset member IMGU as shown in  FIG. 71  separately provided is not needed. 
     For example, an initialization process for one expression unit  9110  or all expression units  9110  may be easily performed through a signal for applying a current to the coil  9120 . 
       FIG. 97  is a schematic perspective front view of an output unit according to another embodiment of the present disclosure. 
     Referring to  FIG. 97 , the output unit IU 8  of the present embodiment may include a base unit  9530 , a driving unit  9540 , an expression unit  9510 , and a coil  9520 . 
     Since the base unit  9530 , the driving unit  9540 , and the expression unit  9510  are identical to those of the above-stated embodiment described above with reference to  FIG. 87 , detailed descriptions thereof will be omitted. 
     For example, the structure of  FIG. 97  may correspond to the structure shown in  FIG. 87  to which the coil  9520  is added. 
     The coil  9520  may be disposed in a first accommodation unit of the base unit  9530 . For example, the coil  9520  may have a shape of a coil would around an extension member  9571  of a support unit  9570  to surround the extension member  9571 . 
     By applying a current to the coil  9520 , a magnetic field for the driving unit  9540  may be generated. For example, an attractive force or a repulsive force may be generated. 
     Therefore, an initialization process may be performed. 
     In the present embodiment, since an initialization process is performed by controlling application of a current to a coil, a process using the movement of the reset member IMGU separately provided is not needed. 
     For example, an initialization process for one expression unit  9510  or all expression units  9510  may be easily performed through a signal for applying a current to the coil  9520 . 
     While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed example embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of protection of the present disclosure should be determined by the technical idea of the appended claims. 
     The specific implementations described in embodiments are illustrative and do not in any way limit the scope of the present disclosure. For clarity of description, descriptions of conventional electronic configurations, control systems, software, and other functional aspects of such systems may be omitted. Also, connections of lines or connecting members between the components shown in the drawings are example illustrations of functional connections and/or physical or circuit connections, which may be replaced with or additionally provided by various functional connections, physical connections, or circuit connections. Also, unless there is a specific reference such as “essential” or “importantly”, it may not be a necessary component for the application of the present disclosure. 
     In the specification of embodiments (especially in the claims), the use of the term “above” and similar referential terms may correspond to both the singular and the plural. also, when a range is stated in the embodiment, it includes the disclosure to which individual values belonging to the range are applied (unless there is a description to the contrary) and is equivalent to that to individual values constituting the range is stated in the detailed description. Finally, the operations constituting the method according to the present disclosure may be performed in an appropriate order, unless explicitly stated or stated otherwise. Embodiments are not necessarily limited to the order in which the operations are described. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the present disclosure unless otherwise claimed. Also, one of ordinary skill in the art will understand that various modifications, combinations, and changes may be made in accordance with design conditions and factors within the scope of the appended claims or their equivalents.