Abstract:
A rotary input apparatus is disclosed. As the rotary input apparatus comprises a rotatable wheel; a magnet joined to a surface of the wheel to co-operate with the wheel and magnetized to have alternating N- and S-poles; an electromagnet part positioned facing the magnet and magnetized to have at least N- or S-pole; a printed circuit board, to which the electromagnet part is joined, including a driving part which supplies an electrical current to the electromagnet part, and a detection element which receives electrical power from the driving part for operation, is positioned facing the magnet, and which detects the rotation of the magnet; a control part which receives a signal and controls the operation of the driving part in correspondence with the received signal; and a base to which the printed circuit board is secured, various types of input may be made through the rotation speed, direction, and angle, etc., and rotation or vibration may be obtained from electrical external signals, to provide an improved visual service.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of Korean Patent Application No. 2006-0044840 filed with the Korean Intellectual Property Office on May 18, 2006, the disclosure of which is incorporated herein by reference in its entirety. 
   BACKGROUND 
   1. Technical Field 
   The present invention relates to a rotary input apparatus. 
   2. Description of the Related Art 
   In general, a mobile terminal has the numbers 0-9 and the symbols * and # on a keypad of 12 keys. In addition to the numbers, there are also alphabet letters as well as consonants and vowels of Korean letters marked on such a keypad, to enable the input of numbers and letters. There are also navigation keys formed above the keypad equipped with a variety of functions such as searching phone numbers, writing and managing text messages, and connecting to the Internet, etc. While there are various forms of navigation keys, such as button types and rotary types, etc., the use of rotary input apparatus is currently increasing, as they enable various functions such as menu browsing, etc. 
   With the widespread use of such rotary input apparatus, there is a desire among users for visual elements, on top of the general functions of the apparatus. In the conventional rotary input apparatus, however, only the basic functions for input by rotation are implemented, so that the users&#39; demands for improved convenience and greater aesthetic value are not fully being satisfied, and various functions still have not yet been implemented such as incoming signal announcing, in which the rotary input apparatus is actuated in response to an incoming signal. 
   SUMMARY 
   The present invention aims to provide a rotary input apparatus which allows improved convenience and greater aesthetic value, as the rotary input apparatus capable of various types of input through the rotation speed, direction, and angle, etc., is made to rotate or vibrate, etc., in response to externally inputted signals. 
   One aspect of the invention provides a rotary input apparatus comprising a rotatable wheel; a magnet joined to a surface of the wheel to co-operate with the wheel and magnetized to have alternating N- and S-poles; an electromagnet part positioned facing the magnet and magnetized to have at least one N- or S-pole; a printed circuit board, to which the electromagnet part is joined, including a driving part which supplies an electrical current to the electromagnet part, and a detection element which receives electrical power from the driving part for operation, is positioned facing the magnet, and which detects the rotation of the magnet; a control part which receives a signal and controls the operation of the driving part in correspondence with the received signal; and a base to which the printed circuit board is secured. 
   Embodiments of the rotary input apparatus may have one or more of the following features. For example, the base may be joined to a mobile terminal, and the control part may receive incoming signals received by the mobile terminal, while a rotation axis may be joined to the center portion of the wheel, with the rotation axis formed to be supported by the base. Also, a guide part may additionally be formed, which guides the rotation of the wheel at a position adjacent to a perimeter portion of the wheel and which is joined to the base, to allow the rotation of the wheel without the rotation axis. Meanwhile, when an external signal is received, the control part may control the operation of the driving part to block the electrical power supplied to the detection element, in order to avoid the possibility of unintentional input being made when the magnet and wheel are rotated due to an external signal. Further, the electromagnet part may include a plurality of electromagnets arranged in constant intervals radially about the center of the printed circuit board. This allows a more stable rotation of the magnet and the wheel joined to the magnet, as the force applied by the electromagnets on the magnet may be provided uniformly. 
   Additional aspects and advantages of the present invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded perspective view of a rotary input apparatus according to an embodiment of the invention. 
       FIG. 2  is a cross-sectional view of a rotary input apparatus according to an embodiment of the invention. 
       FIG. 3  is a block diagram illustrating the flow of a signal in a rotary input apparatus according to an embodiment of the invention. 
       FIG. 4  is a flowchart illustrating an operation of a rotary input apparatus according to an embodiment of the invention. 
       FIG. 5  is a flowchart illustrating an operation of a rotary input apparatus according to another embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   Below, embodiments of the rotary input apparatus according to the invention will be described in more detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, those components are rendered the same reference number that are the same or are in correspondence regardless of the figure number, and redundant explanations are omitted.  FIG. 1  is an exploded perspective view illustrating a rotary input apparatus according to an embodiment of the invention in an unassembled state, and  FIG. 2  is a cross-sectional view illustrating a rotary input apparatus according to an embodiment of the invention in an assembled state. In  FIGS. 1 and 2  are illustrated a wheel  11 , a center hole  14 , a washer  25 , a center key  29 , a holder  15 , fastening portions  17 , holder holes  19 , a center hole  21 , a printed circuit board  31 , dome buttons  33 , a Hall sensor  35 , an electromagnet part  50 , a control part  60 , a base  39 , fastening holes  41 , insertion holes  43 , and a guide part  70 . A rotary input apparatus according to the present embodiment may comprise a rotatably joined wheel  11 , a washer  25 , a center key  29  joined at the center of the wheel  11 , a ring-shaped magnet  13  secured to the bottom of the wheel  11  which rotates together with the wheel  11 , a holder  15  joined to the base  39  which rotatably supports the wheel  11 , a printed circuit board  31  joined to the upper surface of the base  39 , a Hall sensor  35  positioned in a groove of the printed circuit board  31  which is a detection element for sensing the rotation of the magnet  13 , a control part  60  positioned in another groove of the printed circuit board which receives and processes external signals and then transmits the processed signals, an electromagnet part  50  positioned in other grooves of the printed circuit board  31  which receives signals from the control part  60  to allow the flow of an electrical current, and a guide part  70  capable of stably supporting the rotation of the wheel  11 . In the rotary input apparatus according to the present embodiment, the electromagnet part  50 , and the control part  60  which can control the electrical current flowing through the coil patterns  50 , are formed on the printed circuit board  31 , so that the wheel  11  may be rotated not only by external forces applied by the user, but also by electrical signals, etc., from the outside, whereby the user may be provided with an improved visual effect. 
   The wheel  11  may generally be shaped as a circular plate, with a center hole  14  formed in the center through which the center key  29  may be inserted. The wheel  11  may have a plurality of securing protrusions adjacent to the center hole  14  that protrude downwards. The securing protrusions may be inserted into the center hole of the washer  25 , so that the wheel  11  is secured to the holder  15 . The wheel  11  may be rotatably secured to the holder  15 , and on the bottom surface of the wheel  11  may be secured the magnet  13 , which is magnetized to have multiple poles. The wheel  11  may be rotated together with the magnet  13  by user operation, whereby a variety of inputs may be made as the Hall sensor  35  senses the rotation angle, direction, and speed, etc., of the magnet  13 . Also, a portion may be pressed by the user, so that a push protrusion formed on the reverse side of the holder  15  presses the upper surface of a dome button  33  to activate a separate function. 
   The securing protrusions  12 , as illustrated in  FIG. 2 , may be inserted through the center hole  21  of the holder  15  and the center hole of the washer  25 . The washer  25  is inserted and secured onto the center of the holder  15 , whereby the wheel  11  may be secured to the holder  15 . 
   The magnet  13  is attached to the bottom surface of the wheel  11  to be rotated together with the wheel  11 , and such rotation of the magnet  13  may be sensed by the Hall sensor  35  for an input based on the rotation angle. The magnet  13  may have the shape of a ring magnetized to have multiple poles, and the Hall sensor  35  may detect the rotation angle, direction, and speed of the wheel  11  according to the changes in N- and S-poles above the Hall sensor  35 . 
   The holder  15  may be secured to the base  39  and may rotatably support the wheel  11 . Also, the holder  15  may support the wheel  11 , such that when the particular force applied on the wheel  11  is removed, the wheel  11  is returned to its original position due to the elasticity of the holder  15  itself. As illustrated in  FIG. 1 , the holder  15  may have a center hole  21  in the middle, and holder holes  19  may be formed in fastening portions  17  that protrude in four directions around the center hole  21 . The holder  15  may also have ledges  23  formed adjacent the center hole  21 . 
   The fastening portions  17  are protrusion portions formed in particular intervals around the holder  15 , and as illustrated in  FIG. 2 , may be inserted into the fastening holes  41  of the base  39  to prevent the base  39  from becoming detached. The fastening portions  17  may be made of metal or plastic, etc., to have a certain degree of elasticity, and this elasticity may enable the wheel  11  to recover its original position, even when a particular portion of the wheel  11  is pressed so that the wheel  11  becomes tilted. 
   The holder holes  19  formed in the fastening portions  17  are formed in correspondence with the Hall sensor  35  mounted on the printed circuit board  31 , and as illustrated in  FIG. 2 , hold a portion of the Hall sensor  35 . The center hole  21  is formed in the center of the holder  15 . Also, the wheel  11  may be rotatably inserted onto a perimeter  22  forming the center hole  21 , to prevent the wheel  11  from becoming detached. The ledges  23 , as illustrated in  FIG. 2 , may be formed adjacent to the center hole  21 , and the washer  25  may be inserted and secured onto the ledges  23 . 
   As illustrated in  FIG. 1 , a generally circular center hole may be formed in the washer  25 . The washer  25  may be inserted and secured onto the ledges  23  and may allow the wheel  11  to freely rotate  360  degrees. 
   The center key  29  may be inserted through the center hole  14  of the wheel  11  and may be supported by elastic rubber (not shown), etc. The center key  29  may be pressed by the user to perform a particular function, examples of which include connecting to the Internet or receiving DMB (Digital Multimedia Broadcasting), etc. 
   The printed circuit board  31  may have the shape of a circular plate in correspondence with the base  39 , with a plurality of dome buttons  33  formed on one side in correspondence with the push protrusions formed on the reverse side of the holder  15 . Also on the printed circuit board  31  may be formed the electromagnet part  50  and the control part  60  which controls the operation of the electromagnet part  50 , which will be described later in more detail. 
   The dome buttons  33  are pressed by push protrusions (not shown) formed on the reverse side of the holder  15  to perform separate functions. While in this embodiment dome buttons  33  are illustrated that are pressed by the wheel  11 , any composition may be used in which certain pressing performs separate functions. For example, pressure sensors or contact sensors may also be used instead of the dome buttons  33 . 
   The electromagnet part  50 , in reference to  FIG. 1 , may be formed on the printed circuit board  31 , may be formed as coils wound in the shape of triangles, and as will be described later in more detail, may receive signals from the control part  60  for the flow of an electrical current. It is advantageous for the electromagnet part  50  to be arranged in constant intervals radially about the dome button  33  formed at the center of the printed circuit board  31 . This is because when it is not arranged in constant intervals so that there is an imbalance in angles, the forces applied by the electromagnet part  50  with respect to the magnet  13  are not formed uniformly, so that it is difficult for the magnet  13 , and the wheel  11  joined with the magnet  13 , to rotate in a stable manner. While in the present embodiment the electromagnet part  50  is presented as forming an angular balance in 90 degrees about the center of the printed circuit board  31 , it is obvious that the number and configuration of the electromagnets may be varied according to design requirements. 
     FIG. 3  is a block diagram illustrating the flow of a signal in a rotary input apparatus according to an embodiment of the invention. Referring to  FIG. 3 , the control part  60  is illustrated, which is composed of a receiver part  63 , a central processor part  66 , and a transmitter part  69 , as well as the flow of a signal, when there is an external signal, which starts from the external signal, proceeds through the control part  60 , and reaches a controlled unit (e.g. the electromagnet part  50  or the detection element  35 ). 
   The control part  60 , in reference to  FIG. 3 , may include a receiver part  63  which receives signals, a central processor part  66  which processes the received signals, and a transmitter part  69  which transmits the control signals processed at the central processor part  66  to the driving part  55 . Also, the driving part  55  may be positioned between the transmitter part  69  and the electromagnet part  50  to receive control signals from the transmitter part  69  and correspondingly allow the flow of an electrical current to the electromagnet part  50 . 
   Using as an example the case where the rotary input apparatus according to the present embodiment is formed in a mobile terminal, in reference to  FIG. 4 , the central processor part  66  may output a control signal that instructs the driving part not to output any signal when there are no incoming signals (e.g. during stand-by), whereas it may output a control signal that instructs the driving part  55  to output a sine wave when there is an incoming signal (e.g. when there is an incoming phone call or a text message). Meanwhile, the incoming signal may include both signals received from a communication station or relay station, etc., and signals generated by the mobile terminal itself (e.g. signals generated by button input). While in the present invention sine waves are illustrated as the signals provided by the driving part  55  to the electromagnet part  50 , it is obvious that various forms of signals may be outputted according to user preferences and design requirements, and it is also obvious that predetermined signals may be outputted even when there are no external signals received. 
     FIG. 5  is a flowchart illustrating an operation of a rotary input apparatus according to another embodiment of the invention. The control part  60 , in reference to  FIG. 5 , may allow the Hall sensor  35  to operate normally when there are no external signals received (e.g. during stand-by) while stopping the function of the Hall sensor  35  when an external signal is received. In this case, if the function of the Hall sensor  35  is not stopped, a signal is generated and inputted to the Hall sensor  35 , due to the rotation of the magnet  13 , whereby the rotary input apparatus performs a predetermined function (e.g. switching to a text message input mode), and an operation is executed that is not intended by the user. Thus, a means to stop the function of the Hall sensor  35  is necessary to avoid such malfunctions, to prevent the occurrence of unintended input created as the Hall sensor  35  identifies signals generated due to the rotation of the magnet  13 , etc. 
   Receiving holes  37  may be formed in the printed circuit board  31  in correspondence with the holder holes  19  of the holder  15 , and at least a portion of the detection element  35  may be positioned in the receiving hole  37 , as illustrated in  FIG. 2 . Thus, compared to the case of mounting the detection element  35  on the upper surface of the printed circuit board  31 , this embodiment may provide the additional effect of reducing the thickness of the input apparatus by the depth of the receiving hole  37 . 
   The detection element may be a Hall sensor (Hall effect sensor), which is a silicon semiconductor using the effect of electromotive forces generated when electrons experience the Lorentz force in a magnetic field such that their direction is curved. The Hall sensors generate electromotive forces that are proportional to the rotation of the magnet  13  attached to the wheel  11 , which are transferred via the printed circuit board  31  to an outside control unit (not shown). 
   Of course, the detection element is not limited to a Hall sensor, and any element may be used which can detect the rotation of the magnet  13 . For example, an MR (magneto-resistive) sensor or a GMR (giant magneto-resistive) sensor may be used for the detection element. An MR sensor or a GMR sensor is an element of which the resistance value is changed according to changes in the magnetic field, and utilizes the property that electromagnetic forces curve and elongate the carrier path in a solid to change the resistance. Not only are the MR sensor and GMR sensor small in size with high signal levels, but also they have excellent sensitivity to allow operation in low-level magnetic fields, and they are also superior in terms of temperature stability. 
   When the detection element is a Hall sensor  35 , the Hall sensor  35  is secured to the printed circuit board  31  by leads  36 , where the leads  36  are inserted through the insertion holes  43  of the base  39  and secured to the reverse side of the printed circuit board  31 . 
   The base  39 , as illustrated in  FIG. 1 , has the shape of a circular plate, and rotatably supports the holder  15  and the wheel  11 . The base  39  has fastening holes  41  around it in correspondence with the fastening portions  17  of the holder  15 . The fastening portions  17  of the holder  15  are inserted into the fastening holes  41  of the base  39 . Also, insertion holes  43  are formed on the base  39  in correspondence with the receiving holes  37  of the printed circuit board  31 . As illustrated in  FIG. 3 , portions of the Hall sensors  35  are positioned in the insertion holes  43 , whereby the thickness of the rotary input apparatus may further be reduced by the depth of the insertion holes  43 . 
   Meanwhile, a rotational axis (not shown) may be formed in the center portion of the base  39 . In this case, a hole may be formed in the printed circuit board in a position and size corresponding with the rotational axis. Then, the rotational axis may have one end formed on the base  39 , and may penetrate the hole formed on the printed circuit board so that the other end of the rotational axis may be formed in contact with the wheel  11  or the center key  29 , in order thus to support the wheel  11  for stable rotation. 
   Also, a guide part  70  may be formed on the base  39  for the stable rotation of the wheel  11 . The guide part  70  may comprise a stem  71  extending along the outer perimeter of the base  39  in a direction where the wheel is formed, and a curve portion  73  curvedly extending from the stem  71  and covering at least a portion of the wheel  11 . The guide part  70  prevents the wheel  11  from becoming detached due to excessive rotation. 
   A description will now be provided on the operation of the rotary input apparatus according to the present embodiment. 
   When a rotational force is applied by a user on an outer side of the center key  29 , the wheel  11  is rotated while inserted onto the perimeter  22  of the holder  15 , which causes the magnet  13  to rotate together with the wheel  11 . As the magnet  13  has a multiple number of alternately magnetized N- and S-poles, the Hall sensor  35  can sense the changes in poles due to the rotation of the magnet  13 , to recognize the rotation direction, speed, and angle of the wheel  11 . The Hall sensor  35  generates output signals corresponding to the rotation direction, rotation angle, and rotation speed of the wheel  11 , which are transmitted via the printed circuit board  31  to an outside control unit, and the control unit identifies the output signals to perform an input corresponding to the rotation of the wheel  11 . 
   Further, when an outer side of the center key  29  is pressed by a user, the wheel  11  is tilted in one direction while elastically supported by the holder  15 , which causes a push protrusion (not shown) formed on the reverse side of the holder  15  to press a dome button  33 . This allows each of the dome buttons  33  positioned on the printed circuit board  31  to perform its own function. For example, in the input apparatus illustrated in  FIGS. 1 and 2 , there are four equally spaced dome buttons  33  that can be pressed by the push protrusions, where each dome button  33  may function as a hot key for launching a text message function, searching phone numbers, connecting to the Internet, or receiving satellite broadcasts, etc. In addition, the center key  29  may also perform a separate function when pressed by a user. 
   Meanwhile, according to an embodiment of the invention, when the rotary input apparatus is formed on a device capable of receiving an external signal (e.g. a mobile terminal), the central processor part  66  does not make the driving part  55  output any signals during stand-by, so that there is no electric current flowing through the electromagnet part  50 . Thus, there is no electric field formed by the electromagnet part  50 , and there is no force applied on the magnet  13 . This allows the wheel  11  not to rotate and to remain still. On the other hand, when there is a received signal, such as for an incoming phone call or a received text message, the central processor part  66  makes the driving part  55  output a sine wave, etc., which is transferred to the electromagnet part  50 , so that there is an electric current flowing through the electromagnet part  50 . When an electric current is made to flow through the electromagnet part  50 , the flow of the electric current forms an electric field, whereby a force is applied on the magnet  13 . Here, by supplying an alternating current such as of a sine wave, there are changes in the direction of the force, due to the changes in the magnetic field, so that the magnet  13  is able to rotate, as well as the wheel  11  that is formed as a single body with the magnet  13 . Since the signals inputted to the Hall sensor  35  by the rotation of the magnet  13  are blocked by the control part  60 , unintended input may be avoided. 
   Many embodiments, besides the embodiments set forth above, are encompassed within the claims of the present invention. 
   According to embodiments of the present invention comprised as set forth above, a rotary input apparatus may be provided which allows improved convenience and greater aesthetic value, as the rotary input apparatus designed to be capable of various types of input through the rotation speed, direction, and angle, etc., is made to rotate or vibrate, etc., in response to externally inputted signals. 
   While the present invention has been described with reference to particular embodiments, it is to be appreciated that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention, as defined by the appended claims and their equivalents.