Patent Description:
Mobile terminals have become increasingly more functional. Examples of such functions include data and voice communications, capturing images and video via a camera, recording audio, playing music files via a speaker system, and displaying images and video on a display. Some mobile terminals include additional functionality which supports game playing, while other terminals are configured as multimedia players. More recently, mobile terminals have been configured to receive broadcast and multicast signals which permit viewing of content such as videos and television programs.

As such functions become more diversified, the mobile terminal can support more complicated functions such as capturing images or video, reproducing music or video files, playing games, receiving broadcast signals, and the like. By comprehensively and collectively implementing such functions, the mobile terminal may be embodied in the form of a multimedia player or device.

Recently, a flexible display having sufficient elasticity and capable of large deformation has been developed. The size of a mobile terminal can be varied using the deformable nature of the flexible display.

However, the mobile terminal with the variable size will have a height difference at an outer surface thereof when being extended. A hand may be caught in a place where the height difference has occurred, and discomfort may occur when gripping the mobile terminal resulted from the height difference, thereby lowering usability. <CIT> and <CIT> are documents of the related art.

The present disclosure aims to provide a mobile terminal in which switching of a state is made naturally as a slide movement of a frame is stably performed without distortion.

The invention is specified by the independent claim. In the following description, although numerous features may be designated as optional, it is nevertheless acknowledged that all features comprised in the independent claim are not to be read as optional. Provided is a mobile terminal including a first frame, and a second frame capable of switching a state thereof to an extended state by moving in a first direction from the first frame, and to a contracted state by sliding in a second direction opposite to the first direction, wherein the second frame includes a rear portion for at least partially covering a rear surface of the first frame, wherein the first frame includes a first rear surface exposed rearwardly in the contracted state, a second rear surface located frontwardly of the rear portion and not exposed to the outside in the contracted state, wherein at least a portion of the second rear surface is exposed rearwardly in the extended state, and a third rear surface covered by the rear portion in the contracted state and in the extended state, wherein there is a height difference between two of the first rear surface, the second rear surface, and the third rear surface.

The mobile terminal further includes a display unit including a fixed portion coupled to a front surface of the first frame and a variable portion extending in the first direction from the fixed portion to surround the second frame and bent toward the rear surface of the second frame, and a portion rearwardly bent of the variable portion may be disposed overlapping the third rear surface.

The rear portion may further include an accommodating portion in which the display unit located at a rear portion is located, and a covering portion covering the second rear surface in the extended state and covering the third rear surface in the contracted state.

The covering portion may have a thickness corresponding to a height difference between the first rear surface and the second rear surface.

The accommodating portion may have a thickness greater than a thickness of the covering portion, so that the accommodating portion protrudes frontwardly.

A length in the first direction of the first rear surface may be greater than a maximum movement distance in the first direction of the second frame.

The second frame may include a side portion for at least partially covering a side surface of the first frame, the first frame may include a first side surface exposed to the outside in the contracted state, a second side surface located inwardly of the side portion in the contracted state and exposed to the outside in the extended state, and a third side surface located inwardly of the side portion in the contracted state and in the extended state, and there may be a height difference between two of the first side surface, the second side surface, and the third side surface.

The first side surface, the second side surface, and the third side surface may be disposed at the same locations as the first rear surface, the second rear surface, and the third rear surface in the first direction, respectively.

The mobile terminal may further include a linear guide located between the third side surface and the side portion.

The linear guide may include a second guide located on the third side surface of the first frame, and a first guide located in the side portion, wherein the second guide is fastened to the first guide and moves in the first direction or in the second direction.

The side portion may include a metallic antenna radiator, and the mobile terminal may further include an antenna substrate disposed overlapping the first guide, wherein the antenna substrate includes a feeding unit electrically connected to the antenna radiator.

The antenna substrate may protrude laterally more than the first guide.

The second guide may include a bearing ball or a portion made of polyoxymethylene (POM) in contact with the first guide.

The mobile terminal may further include a guide roller located between the third side surface and the side portion.

The mobile terminal may further include a user input unit located in the side portion of the second frame.

The mobile terminal may further include a user input unit positioned on the second side surface of the first frame in the extended state and positioned in the side portion of the second frame in the contracted state, and the user input unit may include a force sensor located inwardly of the second side surface of the first frame.

The mobile terminal of the present disclosure may adjust the size of the screen as needed, so that both portability and usability may be achieved.

In addition, the mobile terminal of the present disclosure may increase usability in the extended state by minimizing the height difference at the outer surface of the mobile terminal that occurs when the mobile terminal is extended.

In addition, the distortion may be prevented during the slide movement, so that the stable slide movement may be achieved and the volume increase by the linear guide may be minimized.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by illustration only, since various changes and modifications within the scope of the invention will become apparent to those skilled in the art from this detailed description.

Description will now be given in detail according to exemplary embodiments disclosed herein, with reference to the accompanying drawings. For the sake of brief description with reference to the drawings, the same or equivalent components may be provided with the same reference numbers, and description thereof will not be repeated. In general, a suffix such as "module" and "unit" may be used to refer to elements or components. Use of such a suffix herein is merely intended to facilitate description of the specification, and the suffix itself is not intended to give any special meaning or function. In the present disclosure, that which is well-known to one of ordinary skill in the relevant art has generally been omitted for the sake of brevity. The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings.

It will be understood that when an element is referred to as being "connected with" another element, the element can be directly connected with the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly connected with" another element, there are no intervening elements present.

The mobile terminal <NUM> is shown having components such as a wireless communication unit <NUM>, an input unit <NUM>, a sensing unit <NUM>, an output unit <NUM>, an interface unit <NUM>, a memory <NUM>, a controller <NUM>, and a power supply unit <NUM>. Referring now to <FIG>, the mobile terminal <NUM> is shown having wireless communication unit <NUM> configured with several commonly implemented components. It is understood that implementing all of the illustrated components is not a requirement, and that greater or fewer components may alternatively be implemented.

The mobile communication module <NUM> can transmit and/or receive wireless signals to and from one or more network entities. Typical examples of a network entity include a base station, an external mobile terminal, a server, and the like. Such network entities form part of a mobile communication network, which is constructed according to technical standards or communication methods for mobile communications (for example, Global System for Mobile Communication (GSM), Code Division Multi Access (CDMA), CDMA2000 (Code Division Multi Access <NUM>), EV-DO (Enhanced Voice-Data Optimized or Enhanced Voice-Data Only), Wideband CDMA (WCDMA), High Speed Downlink Packet access (HSDPA), HSUPA (High Speed Uplink Packet Access), Long Term Evolution (LTE) , LTE-A (Long Term Evolution-Advanced), and the like).

Examples of such wireless Internet access include Wireless LAN (WLAN), Wireless Fidelity (Wi-Fi), Wi-Fi Direct, Digital Living Network Alliance (DLNA), Wireless Broadband (WiBro), Worldwide Interoperability for Microwave Access (WiMAX), High Speed Downlink Packet Access (HSDPA), HSUPA(High Speed Uplink Packet Access), Long Term Evolution (LTE), LTE-A (Long Term Evolution-Advanced), and the like.

Such cameras <NUM> may process image frames of still pictures or video obtained by image sensors in a video or image capture mode. The processed image frames can be displayed on the display unit <NUM> or stored in memory <NUM>. In some cases, the cameras <NUM> may be arranged in a matrix configuration to permit a plurality of images having various angles or focal points to be input to the mobile terminal <NUM>. As another example, the cameras <NUM> may be located in a stereoscopic arrangement to acquire left and right images for implementing a stereoscopic image.

The sensing unit <NUM> is typically implemented using one or more sensors configured to sense internal information of the mobile terminal, the surrounding environment of the mobile terminal, user information, and the like. For example,, the sensing unit <NUM> may alternatively or additionally include other types of sensors or devices, such as a proximity sensor <NUM> and an illumination sensor <NUM>, a touch sensor, an acceleration sensor, a magnetic sensor, a G-sensor, a gyroscope sensor, a motion sensor, an RGB sensor, an infrared (IR) sensor, a finger scan sensor, a ultrasonic sensor, an optical sensor (for example, camera <NUM>), a microphone <NUM>, a battery gauge, an environment sensor (for example, a barometer, a hygrometer, a thermometer, a radiation detection sensor, a thermal sensor, and a gas sensor, among others), and a chemical sensor (for example, an electronic nose, a health care sensor, a biometric sensor, and the like), to name a few. The mobile terminal <NUM> may be configured to utilize information obtained from sensing unit <NUM>, and in particular, information obtained from one or more sensors of the sensing unit <NUM>, and combinations thereof.

The controller <NUM> typically functions to control overall operation of the mobile terminal <NUM>, in addition to the operations associated with the application programs. The controller <NUM> may provide or process information or functions appropriate for a user by processing signals, data, information and the like, which are input or output, or activating application programs stored in the memory <NUM>.

To drive the application programs stored in the memory <NUM>, the controller <NUM> may be implemented to control a predetermined number of the components mentioned above in reference with <FIG>. Moreover, the controller <NUM> may be implemented to combinedly operate two or more of the components provided in the mobile terminal <NUM> to drive the application programs.

<FIG> and <FIG> are diagrams showing the mobile terminal <NUM> that may be varied in size, <FIG> is a front view of a first state and a second state of the mobile terminal <NUM>, and <FIG> is a rear view illustrating the first state and the second state of the mobile terminal <NUM>.

The mobile terminal <NUM> includes frames <NUM> and <NUM> that slide such that the size of the mobile terminal <NUM> may be changed. A first frame <NUM> and a second frame <NUM> that slides relative to the first frame <NUM> are included. When the second frame <NUM> moves in a first direction D1, a state of the mobile terminal <NUM> is switched to an extended state (a second state). In addition, when the second frame <NUM> moves in a second direction opposite to the first direction, the state of the mobile terminal <NUM> is switched to a contracted state (a first state). When the second frame <NUM> of the mobile terminal <NUM> moves in the first direction, because a user is holding a lower portion of the mobile terminal <NUM>, that is, the second frame <NUM>, it may be seen from a user's point of view that the mobile terminal is extended while the first frame <NUM> moves in an upward direction (the second direction).

That is, the movement of the second frame <NUM> in the first direction with respect to the first frame <NUM> has the same meaning as the movement of the first frame <NUM> in the second direction with respect to the second frame <NUM>, and means that the state of the mobile terminal is switched to the extended state. Conversely, the movement of the second frame <NUM> in the second direction with respect to the first frame <NUM> has the same meaning as the movement of the first frame <NUM> in the first direction with respect to the second frame <NUM>, and means that the state of the mobile terminal is switched to the contracted state.

In the following description, the direction in which the mobile terminal <NUM> and the display unit <NUM> thereof are extended or enlarged is defined as a first direction , and the direction in which the mobile terminal contracts or retracts or is reduced to switch from the second state to the first state is defined as a second direction. A direction perpendicular to the first and second directions is defined as a third direction. Description will be made on the assumption that the first and second directions are horizontal directions and the third direction is a vertical direction. However, depending on the arrangement of the mobile terminal <NUM>, the first and second directions may be vertical directions and the third direction may be a horizontal direction.

(a) in <FIG> and (a) in <FIG> show the first state that is the contracted state, and (b) in <FIG> and (b) in <FIG> show the second state that is the extended state. Even in the extended state switched as the second frame <NUM> moves in the first direction, the first frame <NUM> and the second frame <NUM> have an overlapping portion.

In the first state, one of the first frame <NUM> and the second frame <NUM> may be disposed to surround the other and be disposed outward of the other. The first frame <NUM> may be disposed outward of the second frame <NUM> in some embodiments, and the second frame <NUM> may be disposed outward of the first frame <NUM> in some embodiments.

As shown in (b) in <FIG>, as for a rear surface of the mobile terminal, a portion 1012b of the rear surface that was inside in the first state of the first frame <NUM> is exposed to the outside in the second state. The display unit <NUM> may be disposed to cover a front surface of the mobile terminal as shown in <FIG>. As shown in (b) in <FIG>, even in the extended second state, an extended portion is also covered by the display unit <NUM> to prevent a portion inside the mobile terminal from being exposed at the time of the extension.

An area of the display unit <NUM> on the front surface of the mobile terminal may vary depending on whether the frames of the mobile terminal are extended. The display unit <NUM> has a larger size than the frames in the first state, and includes a variable portion that may be positioned on the front surface or the rear surface of the mobile terminal depending on whether the frames are extended.

As such, a flexible display unit <NUM> which is bendable may be used as the display unit such that the position of the display unit may move to front side or rear side. The flexible display unit <NUM> may be a display unit capable of maintaining a flat state like a conventional flat panel display and capable of warping, bending, folding, twisting, or rolling like paper. The flexible display unit <NUM> refers to a display which is manufactured on a thin and flexible substrate and is thus lightweight and robust as not to be easily broken. The flexible display unit according the present disclosure may be bent in a specific direction, and may be arranged such that the curvature thereof may change in the first direction.

In addition, an electronic paper is a display technology to which properties of general ink are applied. The electronic paper may be different from the conventional flat panel display in using reflected light. The electronic paper may change information using a twisted ball or electrophoresis using a capsule.

In a state in which the flexible display unit <NUM> is not deformed (e.g., a state of having an infinite curvature radius, hereinafter referred to as a basic state), a display area of the flexible display unit <NUM> becomes flat. In a state in which the flexible display unit <NUM> is deformed by an external force from the basic state (e.g., a state of having a finite radius of curvature, hereinafter referred to as a deformed state), the display area may become a curved face. As shown, information displayed in the deformation state may be visual information output on the curved face. Such visual information is implemented by independently controlling light emission of sub-pixels arranged in a matrix. The sub-pixel refers to a minimum unit for implementing one color. When external force is applied to the flexible display unit <NUM>, the flexible display unit <NUM> may be deformed to switch from the default state, which is the flat state, to a bent state, which is not the flat state.

The flexible display unit <NUM> may be combined with a touch sensor to implement a flexible touch screen. When a touch is made on the flexible touch screen, the controller <NUM> (see <FIG>) may perform control corresponding to such touch input. The flexible touch screen may be configured to detect the touch input in the deformed state as well as in the basic state.

The touch sensor detects the touch (or touch input) applied on the touch screen using at least one of various touch schemes such as a resistive film scheme, a capacitance scheme, an infrared scheme, an ultrasonic wave scheme, a magnetic field scheme, and the like.

As an example, the touch sensor may be configured to convert a change in pressure applied on a specific portion of the touch screen, capacitance generated at the specific portion, or the like into an electrical input signal. The touch sensor may be configured such that a touch object applying a touch on the touch screen may detect touched position and area on the touch sensor, a pressure during the touch, a capacitance during the touch, and the like.

Further, the mobile terminal <NUM> may have a deformation detection means for detecting the deformation of the flexible display unit <NUM>. Such deformation detection means may be included in the sensing unit <NUM> (see <FIG>).

The deformation detection means may be disposed in the flexible display unit <NUM> or a case (first to second frames <NUM> to <NUM> to be described later) to detect information related to the deformation of the flexible display unit <NUM>. In this connection, the information related to the deformation may include a direction in which the flexible display unit <NUM> is deformed, a degree of the deformation, a deformed position, a deformed time, an acceleration at which the deformed flexible display unit <NUM> is restored, and the like. In addition, the information related to the deformation may include various kinds of information that may be detected due to the bending of the flexible display unit <NUM>.

In addition, the controller <NUM> may change information displayed on the flexible display unit <NUM> or generate a control signal for controlling a function of the mobile terminal <NUM> based on the information related to the deformation of the flexible display unit <NUM> detected by the deformation detection means.

The deformation of the flexible display unit <NUM> may vary depending on the positions of the first frame <NUM> and the second frame <NUM>. As shown in <FIG>, since the bending position on the flexible display unit <NUM> is determined according to the positions of the first frame and the second frame, the bending deformation position of the flexible display unit <NUM> and the area thereof positioned on the front may be calculated based on the positions of the first frame <NUM> and the first frame <NUM> in place of the deformation detection means of the flexible display unit <NUM>.

The state conversion (first or second state) of the flexible display unit <NUM>, i.e., the size change at the front and rear faces of the mobile terminal <NUM> of the display unit <NUM> based on the size change of the mobile terminal <NUM> may be performed manually by a force applied by the user, but may be not limited to such manual scheme. For example, when the mobile terminal <NUM> or the flexible display unit <NUM> is in the first state, the mobile terminal <NUM> or the flexible display unit <NUM> may be converted into the second state by the user or an application command without the external force applied by the user. As such, in order for the flexible display unit <NUM> to be automatically deformed without the external force, the mobile terminal <NUM> may include a driving unit <NUM>, which will be described later.

The flexible display unit <NUM> of the present disclosure is bent <NUM> degrees by rolling around a side portion of the mobile terminal <NUM> facing in the first direction. Accordingly, based on the side portion of the mobile terminal <NUM>, a part of the flexible display unit <NUM> is disposed on the front of the mobile terminal <NUM>, and the other part of the flexible display unit <NUM> is disposed on the rear of the mobile terminal <NUM>. For simplicity, the part of the flexible display unit <NUM> positioned on the front is called a front face, and the other part of the flexible display unit <NUM> positioned on the rear is called a rear face. As illustrated in <FIG>, the mobile terminal may extend in the first direction or contract in the second direction opposite to the first direction. In this case, the area of the flexible display unit <NUM> positioned on the front changes. That is, the sizes of the front face and the rear face may be changed according to a change in the state of the mobile terminal.

The part of the flexible display unit <NUM> positioned on the front of the mobile terminal <NUM> may be immovably fixed to the front surface of the first frame <NUM>, and the other part thereof positioned on the rear of the mobile terminal <NUM> may be movably arranged on the rear of the mobile terminal <NUM>.

In addition, the flexible display unit <NUM> may be rolled on or released at the side portion in the first direction of mobile terminal. Accordingly, the rear face of the display unit <NUM> moves, so that the size of the front face of the display unit <NUM> may be adjusted. Since the size of the flexible display unit <NUM> is determined and the flexible display unit <NUM> is formed of one continuous body, an area of rear face of the display unit <NUM> decreases as an area of the front face of the display unit <NUM> increases. Such a display unit <NUM> may be rolled in a second frame <NUM>, which is movable relative to a first frame <NUM> to be described later, more correctly, on one of sides of the second frame <NUM>. The display unit <NUM> may be withdrawn or pulled out from or inserted or pushed into the second frame <NUM> while being rolled in the second frame <NUM> along a moving direction of the second frame <NUM> to adjust the area of the display unit <NUM> on the front face of the mobile terminal <NUM>.

In addition, the display unit <NUM> may be bent <NUM> degrees while forming a curved surface in the second frame <NUM> so as to be disposed on both the front surface and the rear surface of the mobile terminal <NUM>. For such an arrangement of the display unit <NUM>, the second frame <NUM> may include a roller rotatably disposed therein. The roller may be disposed at any position inside the second frame <NUM>.

However, the display unit <NUM> has to be spread flat on the front surface and the rear surface of the mobile terminal <NUM> in order to provide the user with a good quality screen. For such spreading, an appropriate tension must be provided to the display unit <NUM>. To provide appropriate tension, the roller may be placed at an end in the first direction of the second frame <NUM>. Such roller may extend in the second direction and may be rotatably coupled to the second frame <NUM>.

The display unit <NUM> may be wound on the roller while being gently curved with a predetermined curvature. The flexible display unit <NUM> may include a first surface that outputs an image thereon and is exposed to the outside, and an inner surface facing toward the frame opposite to the first surface. The roller may be installed to freely rotate in the second frame <NUM> while in contact with the inner surface of the display unit <NUM>. Accordingly, the roller may actually move the display unit <NUM> in a lateral direction of the mobile terminal <NUM>, that is, in a direction perpendicular to a longitudinal direction. As will be described later, when the second frame <NUM> slides, by the tension applied by the second frame <NUM>, the display unit <NUM> may move to the front surface or the rear surface of the mobile terminal <NUM> relative to the second frame <NUM> in different directions (i.e., the first direction D1 or the second direction D2). The roller may guide such movement while rotating.

In addition, the roller may be disposed adjacent to the end in the first direction of the second frame <NUM>, and a side frame disposed at the end in the first direction of the second frame <NUM> may be included to prevent damage to the display unit <NUM> wound on the roller.

While extending and contracting in the first and second directions D1 and D2, the second frame <NUM> may overlap the first frame <NUM>, precisely a first front portion <NUM> and a first rear portion <NUM> of the first frame <NUM> so as not to interfere with the first frame <NUM>. More specifically, the display unit <NUM> may be coupled and supported by the first front portion <NUM> of the first frame <NUM> as described above, and thus, there is no need to be additionally supported by a second front portion of the second frame <NUM>. Rather, when the second front portion is interposed between the first front portion <NUM> and the display unit <NUM>, the display unit <NUM> may be deformed or damaged by friction with the repeatedly moving second front portion.

Accordingly, the second front portion may be disposed below the first front portion <NUM> or may be inserted between two sheets of the first front portion <NUM>. A second rear portion <NUM> of the second frame <NUM> may be disposed to face a rear surface of the first rear portion <NUM> of the first frame <NUM>. That is, a front surface of the second rear portion <NUM> may face the rear surface of the first rear portion <NUM>. In addition, in order to stably support the movement of the second frame <NUM>, the rear surface of the first rear portion <NUM> may be in contact with the front surface of the second rear portion <NUM>. By such arrangement, the second rear portion <NUM> may be exposed to the outside of the first frame, more precisely, of the first rear portion <NUM>, and may be coupled to the display unit <NUM>.

In addition, the second frame <NUM> may extend and reduce the size of the mobile terminal <NUM> itself, particularly the front surface of the mobile terminal <NUM>, by the extension and the contraction in the first and second directions D1 and D2. The display unit <NUM> has to move as much as the extended or reduced front surface in order to switch the state thereof to the intended first and second states. However, when fixed to the second frame <NUM>, the display unit <NUM> is not able to be moved smoothly to fit the front surface of the mobile terminal <NUM> to be extended or reduced. For this reason, the display unit <NUM> may be movably coupled to the second frame <NUM>.

Typically, an antenna is disposed in the case or the housing of the mobile terminal <NUM>, but a portion where the antenna is installed in the case or the housing may be limited because of the flexible display unit <NUM> that covers not only the front face of the mobile terminal <NUM> but also the rear face thereof. For this reason, the antenna may be implemented on the flexible display unit <NUM>. An antenna on display (AOD) is an antenna in which a transparent film is formed by stacking an electrode layer and a dielectric layer that have patterns engraved thereon, respectively. The antenna on display may be implemented thinner than an antenna implemented using a laser direct structuring (LDS) technology using a conventional copper nickel plating scheme, so that the antenna on display may not be exposed to the outside without affecting a thickness. In addition, the antenna on display may transmit and receive a signal directly to or from the display unit <NUM>. Accordingly, the antenna on display may be used in the mobile terminal <NUM> in which the display unit <NUM> is located on the both faces of the mobile terminal <NUM> as in the present disclosure.

The flexible display unit <NUM> located on the rear surface may be disposed to be exposed to the outside, but there may be a risk of damage when an end of the display unit <NUM> is exposed to the outside. In addition, when the state of the mobile terminal <NUM> is switched to the second state, the second rear portion <NUM> of the second frame covered by the display unit <NUM> may be exposed to expose a structure that guides the slide movement of the display unit <NUM>. In order to avoid such problem, as shown in <FIG>, a rear surface cover <NUM> may be further included at the rear of the second frame <NUM> on which the display unit <NUM> is located.

The rear surface cover <NUM> may be made of an opaque material. When the rear surface cover <NUM> is transparent, information may be provided to the user by utilizing the display unit <NUM> located on the rear surface in the first state. For example, when the user takes a picture in a direction of the user with a camera located on the rear surface of the mobile terminal, a preview image of the camera may be viewed through the display unit <NUM> located on the rear surface. Alternatively, when the mobile terminal is placed with the rear surface facing upward, an alarm or the like may be provided through the display unit <NUM> located on the rear surface.

However, when the display unit <NUM> moves in the second state, an inner portion of the mobile terminal may be seen. Thus, the display unit <NUM> may be mirror-coated such that the inner portion of the mobile terminal is visible only in an ON state, that is, in a case in which light is emitted from the inside.

<FIG> and <FIG> are exploded perspective views of the mobile terminal in accordance with an embodiment. <FIG> is an exploded perspective view of the mobile terminal as viewed from the front side, and <FIG> is an exploded perspective view of the mobile terminal as viewed from the rear side.

The mobile terminal <NUM> of the present disclosure includes frames <NUM> and <NUM> in which components are mounted, and the frames <NUM> and <NUM> of the present disclosure may vary in size in the first direction as shown in <FIG>. One or more frames <NUM> and <NUM> move relative to each other, and sizes thereof may vary in the first direction. Electronic components are mounted in the frames <NUM> and <NUM>, and the flexible display unit <NUM> is located out of the frames <NUM> and <NUM>.

Since the mobile terminal <NUM> of the present disclosure includes the flexible display unit <NUM>, the flexible display unit <NUM> may be combined in a form surrounding front faces and rear faces of the frames <NUM> and <NUM>. The frame may include the first frame <NUM> and the second frame <NUM> moving in the first direction with respect to the first frame <NUM>. The first frame <NUM> and the second frame <NUM> include front portions, a rear portions, and side portions, respectively, and are coupled to each other.

First, the first frame <NUM> may correspond to a main body of the mobile terminal <NUM>, and may define a space for accommodating therein various parts between the first front portion <NUM> and the first rear portion <NUM>. In addition, the first frame <NUM> may accommodate the second frame <NUM> movably coupled to the first frame <NUM> in such a space. More specifically, the first frame <NUM> may include the first front portion <NUM> disposed at a front portion of the mobile terminal <NUM> to support a front surface of the display unit <NUM>, and the first rear portion <NUM> disposed on a rear surface of the mobile terminal and equipped with various parts.

Such first front portion <NUM> and first rear portion <NUM> may be spaced apart from each other at a predetermined spacing to defined the predetermined space therebetween, and may be connected to each other by a first side portion <NUM>. The first side portion <NUM> may be formed integrally with the first rear portion <NUM> or the first front portion <NUM>. The camera <NUM>, the audio output module <NUM>, an input/output terminal, the controller <NUM>, and the power supply unit <NUM> may be accommodated in the space within the first frame <NUM> as the parts of the mobile terminal <NUM>. For example, the controller <NUM> may be a circuit board <NUM> including a processor and an electronic circuit for controlling an operation of the mobile terminal, and the power supply unit <NUM> may be a battery and related parts. In addition, the driving unit <NUM> for controlling the slide movement of the second frame <NUM> to be described later may be accommodated in the first frame <NUM>.

As described above, the display unit <NUM> has the continuous body, and thus, may be disposed on both the front face and the rear face of the mobile terminal <NUM> while being rolled in the mobile terminal <NUM>. The display unit <NUM> may include the front face positioned at the front face of the mobile terminal <NUM>, the rear face positioned at the rear face of the mobile terminal <NUM>, and the side face positioned between the front face and the rear face thereof and surrounding the side face of the mobile terminal. The front face and the rear face of the display unit <NUM> are flat, and the side face of the display unit <NUM> may form a curved face. The flexible display unit <NUM> may be damaged when being bent at an angle. Thus, the flexible display unit <NUM> may be formed to be bent with a predetermined curvature at the side face.

The display unit <NUM> may be divided into a fixed portion and a variable portion. The fixed portion means a portion fixed to the frame. Because of being fixed to the frame, the fixed portion maintains a constant shape without changing a bending degree. On the other hand, the variable portion means a portion in which a bending angle or a position of the bent portion changes. The variable portion in which the position or bending angle of the bent portion changes requires a structure for supporting a rear face of the variable portion in response to the change.

The fixed portion is coupled to the first frame of the display unit and is always positioned on the front face portion of the display unit to form a portion of the front face portion of the display unit. The variable portion includes a side face located at a side portion of the mobile terminal, and a position of the side face varies depending on the position of the second frame. Based on a side face, an area of a portion disposed on the front face portion of the display unit and an area of a portion disposed on the rear face portion of the display unit vary. That is, a portion of the variable portion may be the front face and another portion of the variable portion may be the rear face based on the first and second states. The variable portion is positioned in the first direction with respect to the fixed portion relative to the mobile terminal, and an end of the variable portion is bent toward the rear face of the mobile terminal and slides on the rear face of the second frame <NUM>.

A slide frame that guides the slide movement on a rear surface of the second frame is coupled to an end of the variable portion of the display unit. The slide frame moves in the first direction on the second frame at the same time when the second frame moves in the first direction. As a result, a moving distance of the slide frame is twice as a moving distance of the second frame with respect to the first frame. In one example, as well shown in <FIG>, the first rear portion <NUM> of the mobile terminal <NUM> may include a first rear surface exposed to the outside without being covered by the display unit <NUM> even in the first state. The physical input unit <NUM>, such as various buttons, switches, the camera <NUM>, and a flash, for manipulation of the mobile terminal <NUM>, and the sensing unit <NUM>, such as the proximity sensor <NUM> or a fingerprint sensor, may be disposed on the first rear surface. The first rear portion <NUM> excluding a first rear surface 1012a may be covered by the display unit <NUM> in the first state as shown in (a) in <FIG>, and may be exposed in a rearward direction in the second state as shown in (b) in <FIG>.

In a typical bar-type terminal, the display unit is disposed only on the front surface of the terminal. Therefore, a main camera is disposed on the rear surface of the terminal in order for the user to photograph an object on an opposite side while looking the object through the display unit <NUM>. In one example, an additional auxiliary camera is required on a front surface of the terminal in order for the user to take a picture of himself/herself while looking himself/herself through the display unit.

However, in the mobile terminal <NUM> of the present disclosure, the display unit <NUM> is located on both the front surface and the rear surface of the mobile terminal <NUM>. Therefore, when the user takes the picture of himself/herself, a display unit on the same side as the camera <NUM>, that is, a rear surface of the display unit <NUM> may be used. In addition, when the user photographs the object on the opposite side of the user, a front surface of the display unit <NUM> on a side opposite to the camera <NUM> may be used. For this reason, the mobile terminal <NUM> may photograph the object located on the opposite side of the user or photograph the user using one camera <NUM>. The camera may include a plurality of cameras having different angles of view, such as a wide angle, a super wide angle, a telephoto, and the like. The proximity sensor, the audio output module, and the like may be located on the first rear surface 1012a in addition to the camera, and an antenna <NUM> may be installed on the first rear surface 1012a. An exposed decoration may be attached to the first rear surface 1012a to protect the camera, the sensing unit, and the like in consideration of an exterior design. A portion of the exposed decoration corresponding to the camera <NUM>, the sensing unit <NUM>, and the like may be transparent, and the remaining portion thereof may have a predetermined pattern or color in consideration of the design so as not to expose the internal parts.

The first side portion <NUM> may extend along edges of the first front portion <NUM> and the first rear portion <NUM> to surround a perimeter in the lateral direction of the first frame <NUM>, may form an appearance of the mobile terminal <NUM>. However, as mentioned above, because the second frame <NUM> is accommodated in the first frame <NUM> and is also movably coupled thereto, in order to allow the relative movement of the second frame <NUM> with respect to the first frame <NUM>, a portion of the first frame <NUM> needs to be opened. As well shown in <FIG>, as an example, the second frame <NUM> is coupled to the first frame <NUM> to be movable in the first direction, so that the first side portion <NUM> is not formed on a side surface in the first direction of the first frame <NUM>, thereby opening the side surface in the first direction of the first frame <NUM>. Because the first side portion <NUM> is exposed to the outside of the mobile terminal <NUM>, the interface unit <NUM> for connecting a power port or an ear jack, the user input unit <NUM> such as a volume button, or the like may be disposed. When the first side portion <NUM> contains a metal material, the first side portion <NUM> may serve as an antenna. The second frame <NUM> may include a second front portion (not shown) disposed at the front portion of the mobile terminal <NUM> and a second rear portion <NUM> disposed on the rear surface of the mobile terminal <NUM>. Like the first front portion <NUM> and the first rear portion <NUM> of the first frame <NUM>, the second front portion and the second rear portion <NUM> may be formed of a substantially flat plate-shaped member. In addition, the second frame <NUM> also accommodates various parts therein, and should not interfere with the parts accommodated in the first frame <NUM> during the movement. Accordingly, the second front portion and the second rear portion <NUM> may be coupled in a state spaced apart from each other to define a predetermined space therebetween, and may have shapes for not interfering with the parts in the first frame <NUM>.

A second side portion <NUM> that forms a side surface of the second frame <NUM> may be included. The first side portion <NUM> may be formed long and the second side portion <NUM> of the second frame <NUM> may be located inward of the first side portion <NUM> such that only the first side portion <NUM> is exposed to the outside in the first state. However, in the present embodiment, as shown in <FIG> and <FIG>, the first side portion <NUM> of the first frame <NUM> may be formed to include a first side surface 1013a, which is a portion disposed side by side with the first rear surface 1012a and exposed to the outside, and a second side surface 1013b that is selectively exposed.

In the first state, the first side portion <NUM> and the second side portion <NUM> may together constitute side portions in a third direction and a fourth direction of the mobile terminal. The second side surface 1013b of the first side portion <NUM> covered by the second side portion <NUM> may be exposed to the outside as shown in (b) in <FIG> and (b) in <FIG> in the second state.

(a) in <FIG> is a cross-sectional view taken along a A-A in <FIG>, and (b) in <FIG> is a cross-sectional view taken along a line B-B, which are conceptual diagrams showing only the first frame <NUM>, the second frame <NUM>, and the display unit <NUM>. In the first state, the display unit <NUM> positioned on the rear surface of the mobile terminal <NUM> may be covered with the rear surface cover <NUM> as the second frame <NUM> is positioned at the second rear portion <NUM>. When the state of the mobile terminal <NUM> is switched to the second state, an area of the display unit <NUM> located on the front surface increases and an area of the display unit <NUM> located on the rear surface decreases.

The second rear portion <NUM> of the second frame <NUM> needs to have a predetermined thickness because the rear surface of the display unit <NUM> is located and slides on the second rear portion <NUM>. When the state of the mobile terminal <NUM> is switched to the second state as shown in (b) of <FIG>, the second rear surface 1012b covered by the second rear portion <NUM> is exposed to the outside, and the exposed second rear surface 1012b is recessed in a forward direction than the first rear surface 1012a to generate a height difference corresponding to thickness of the second rear portion <NUM>.

When the height difference between the first rear surface 1012a and the second rear surface 1012b is large, there is a problem of deteriorating a feeling of use because of a large sense of heterogeneity during use. In addition, when a rail <NUM> of a linear guide <NUM> for assisting the slide movement of the second frame <NUM> is exposed in a rearward direction of the mobile terminal <NUM> in the second state as shown in (b) in <FIG>, aesthetics is impaired and an unevenness of the rail comes into contact with a hand. To increase usability, it is necessary to reduce the height difference between the first rear surface 1012a and the second rear surface 1012b.

<FIG> shows rear views of a first state and a second state according to an embodiment of a mobile terminal, and <FIG> shows cross-sectional views taken along a line D-D and a line E-E in <FIG>. In the present embodiment, the rear surface of the first frame <NUM> is formed in multiple steps in order to reduce the height difference between the first rear surface 1012a that is always exposed and the second rear surface 1012b exposed in the second state. In the present embodiment, the rear surface of the first frame is composed of three portions with different heights, and the heights of the three portions gradually decrease to reduce the height difference between the second rear surface 1012b exposed to the outside in the second state and the first rear surface 1012a.

A size of the first rear surface 1012a that is always exposed to may be small compared to the embodiment described above to form the rear surface of the first frame <NUM> in the multiple steps. In addition, first frame <NUM> may be formed by distinguishing between the second rear surface 1012b that is covered by the second rear portion <NUM> in the first state and exposed to the outside in the second state, and a third rear surface 1012c that is always located inside the second rear portion <NUM> of the second frame <NUM>.

Sections 1012a, 1012b, and 1012c of the rear surface of the first frame <NUM> have the height differences therebetween, the height difference between the second rear surface 1012b exposed to the outside in the second state and the first rear surface 1012a is minimized, and the third rear surface 1012c is formed so as not to be exposed to the outside, so that the bar shape of the mobile terminal <NUM> may be maintained even in the second state as shown in <FIG>.

Because the third rear surface is not exposed to the outside, a frame for covering the internal parts such as the first rear surface 1012a or the second rear surface 1012b may be omitted, and the parts such as the battery may be disposed to directly face the second frame.

The second rear portion <NUM> may include a covering portion 1022a that is disposed overlapping the second rear surface 1012b and an accommodating portion 1022b that is disposed overlapping with the third rear surface 1012c. The covering portion 1022a may have a thickness corresponding to a height difference between the first rear surface 1012a and the second rear surface 1012b. The covering portion 1022a serves to cover the third rear surface 1012c in the second state without mounting the parts therein. Because the covering portion 1022a is located on the second rear surface 1012b in the first state, and is able to be formed thinly, the height difference between the first rear surface 1012a and the second rear surface 1012b may be minimized.

A length of the second rear surface 1012b and a length in the first direction of the covering portion 1022a may be greater than a slide movement distance of the second frame <NUM> such that the third rear surface 1012c is not exposed in the second state. In the second state, the covering portion 1022a and the second rear surface 1012b may be partially overlapped each other and the covering portion 1022a may be supported so as not to be recessed inward even when being pressed by the user.

The accommodating portion 1022b, which is a portion in which the display unit <NUM> is located in the first state, may have a predetermined thickness to accommodate the display unit <NUM> therein. The third rear surface 1012c may be more recessed in the forward direction as the accommodating portion 1022b became thicker than the covering portion 1022a to accommodate the display unit <NUM> therein.

A magnitude of a height difference between the accommodating portion 1022b and the covering portion 1022a may correspond to a height difference between the second rear surface 1012b and the third rear surface 1012c. Even in the second state, an end in the second direction of the accommodating portion 1022b may be partially positioned on the second rear surface 1012b to support the second rear portion <NUM> of the second frame <NUM>.

The accommodating portion 1022b may have a space in which the display unit moves, and may include the rear surface cover that covers the rear surface of the display unit. The rear surface cover <NUM> may be flush with the covering portion 1022a and constitute the rear surface of the second frame. That is, the rear surface cover <NUM> may be extended to constitute the covering portion 1022a.

The rear surface cover <NUM> may contain a light-transmitting material such that an image output from the display unit <NUM> positioned on the rear surface is visible through the rear surface cover <NUM>. The light-transmitting material may be coated or a film may be attached to the light-transmitting material to selectively transmit light. An interior of the rear surface cover <NUM> is visible only when the display unit is activated, and the interior is not visible from the outside when the display unit <NUM> is deactivated, thereby preventing visual exposure of the internal parts.

<FIG> is a view showing parts mounted inside a mobile terminal of the present disclosure. <FIG> shows that the rear portions <NUM> and <NUM> and the rear surface cover <NUM> that cover the display unit <NUM> and the rear surface of the mobile terminal. (a) shows the first state and (b) shows the second state. Most of the parts may be mounted inside the first frame <NUM>. The main board <NUM>, the battery <NUM>, the camera <NUM>, the motor <NUM> of the driving unit <NUM>, and the like may be mounted in the first frame <NUM>.

The battery <NUM>, which is a part having the greatest weight inside the mobile terminal <NUM>, is more stable to be located at a lower portion than at an upper portion in the drawing. In particular, in a case in which the battery <NUM> extends in a downward direction (in the first direction) as shown in (b), when the battery <NUM> is positioned at the upper portion, a center of gravity becomes more biased upwardly.

Therefore, in the first frame <NUM>, the camera <NUM> or the main board <NUM> may be located at an upper portion, and the battery <NUM> may be disposed below the main board <NUM>. Because the battery <NUM> and the main board <NUM> are both located in the first frame <NUM>, there is no change in a location of the battery <NUM> and the main board <NUM> when the battery <NUM> and the main board <NUM> are connected to each other. However, in order to connect an antenna using the second side portion <NUM> of the second frame <NUM>, the user input unit <NUM>, or the like to the main board <NUM>, a shape of a flexible board or a cable 185b may be changed.

A coil antenna <NUM> that performs short-range wireless communication, such as a payment antenna or an NFC antenna, may be disposed on a rear surface of the battery <NUM>. The coil antenna <NUM> is preferably disposed adjacent to the rear surface of the mobile terminal <NUM>. When the coil antenna <NUM> is located on the rear surface of the battery <NUM>, because the coil antenna <NUM> is located in the first frame <NUM>, there is no change in a connection between the coil antenna <NUM> and the main board <NUM>.

When the coil antenna <NUM> is disposed in the second rear portion <NUM> of the second frame <NUM>, together with the connection for connecting the user input unit <NUM> or the antenna using the second side portion of the second frame described above, the cable 185b or the flexible board 185a that is spread at the time of the extension may be used.

An interior of the second frame <NUM> in the extended second state is empty. Although a rolling hinge <NUM> supports the extended rear surface of the display unit <NUM>, because the rolling hinge <NUM> is driven in a state caught on a slide rail of the second frame at ends in the third and fourth directions of the display unit <NUM>, there is a problem in that a force for supporting a central portion of the display unit <NUM> is weak.

When the second frame <NUM> includes the second front portion located on the rear surface of the first front portion of the first frame <NUM> in the first state and located on the rear surface of the rolling hinge <NUM> in the second state, although the second front portion is positioned on a rear surface of the rolling hinge <NUM> to support the display unit <NUM>, a thickness of the second front portion is too small to support the display unit <NUM>.

A support link <NUM> may be further included to support the display unit <NUM> located on the rear surface of the first frame <NUM> in the extended state. The support link may include a first link coupled to the first frame <NUM> and a second link coupled to the second frame, and an angle between the first link and the second link may be varied through hinge coupling. The support link <NUM> is folded in the first state and unfolded in the second state to support a middle portion of the rolling hinge <NUM>. When the second frame includes the second front portion, the support link <NUM> may be located on a rear surface of the second front portion.

When the support link <NUM> is unfolded into a straight line shape in the second state, it is difficult to switch the state of the support link <NUM> back to the folded state. Thus, as shown in (b) in <FIG>, even in the extended state of the mobile terminal <NUM>, the support link <NUM> is unfolded at an angle within <NUM> degrees.

The connection 185b that connects the parts mounted in the second frame <NUM> to the main board <NUM> of the first frame <NUM> described above may be formed to be movable with the support link <NUM> as shown in <FIG> so as not to be caught in other parts when a shape thereof changes.

The driving unit <NUM> includes a driving motor <NUM> that moves the second frame <NUM> in the first direction, and is located in the first frame <NUM>, a pinion gear (not shown) that rotates by receiving a rotational force of the driving motor <NUM>, and a rack gear <NUM> that engages with the pinion gear and moves linearly. In the drawing, the pinion gear is covered by the rack gear <NUM>. The rack gear <NUM> extends in the first direction and engages with the second frame <NUM>. When the driving motor <NUM> operates, the rack gear <NUM> moves the second frame <NUM> while moving in the first direction or the second direction.

The driving motor <NUM> may be disposed adjacent to an end in the first direction of the first frame <NUM> so as to move the second frame as far as possible. In consideration of arrangement of the battery <NUM> and other parts, the rack gear <NUM> may be disposed to be biased in the third direction. In order to prevent distortion caused by such asymmetric driving unit <NUM> from occurring, a component for assisting the slide movement in the first direction or the second direction of the second frame <NUM> is required.

<FIG> is a cross-sectional view taken along a C-C in <FIG>. In order to prevent tilting of the second frame <NUM> during the slide movement, the linear guide <NUM> that guides the slide movement in the first direction or the second direction may be further included. The linear guide <NUM> may include a first guide <NUM> extending in the first direction and a second guide <NUM> fastened to the first guide <NUM> and moving along the first guide <NUM>. The first guide <NUM> and the second guide <NUM> may be coupled to the first frame <NUM> and the second frame <NUM>, respectively.

When disposing the linear guide <NUM> to be directed in a front and rear direction of the mobile terminal <NUM> as shown in <FIG>, because the linear guide <NUM> occupies a large volume, a portion in which the linear guide <NUM> is formed must be recessed, or the first guide <NUM> may be exposed to the outside as shown in (b) in <FIG>.

<FIG> is a conceptual diagram showing locations of the first side surface 1013a to a third side surface, the side portion, and the linear guide <NUM> of the mobile terminal. When the first guide <NUM> and the second guide <NUM> are disposed side by side in the third direction, it is possible to prevent the thickness of the mobile terminal from increasing. However, because a space is required in the lateral direction, the side portion may also have a three-step structure like the rear surface structure described above.

The first side surface 1013a that is always exposed to the outside, the second side surface 1013b that is at least partially exposed to the outside only in the second state, and a third side surface 1013c that is always located inside without being exposed to the outside may be included, and height differences may exist between the first to third side surfaces 1013a to 1013c.

A length of the second side surface 1013b may be greater than the slide movement distance in the first direction of the second frame <NUM>, and the linear guide <NUM> may be positioned on the third side surface 1013c. The second side surface 1013b may be placed side by side with the second rear surface 1012b, and the third side surface 1013c may be disposed side by side with or slightly displaced from the third rear surface 1012c.

The second side portion <NUM> of the second frame <NUM> covers the second side surface 1013b and the third side surface 1013c in the first state, and the third side surface 1013c is recessed inwardly of the second side surface 1013b. thus, the linear guide <NUM> is disposed using a space between the third side surface 1013c and the second side portion <NUM> of the second frame <NUM>.

In the drawing, the first guide <NUM> of the linear guide <NUM> is shown as being coupled to the second frame <NUM>, but the first guide <NUM> and the second guide <NUM> may be arranged in reverse. However, when it is located in the second side portion <NUM> of the second frame <NUM>, it is possible to secure a space for mounting the antenna, the user input unit, and the like in the second side portion <NUM>.

<FIG> is a cross-sectional view taken along a line F-F in <FIG>. The first guide <NUM> and the second guide <NUM> will be described in more detail with reference to <FIG>.

In order not to increase a bezel in the third direction of the display unit <NUM> located on the front surface even when the third side surface 1013c is recessed inwardly of the second side surface 1013b, the linear guide <NUM> may be positioned facing rearward in a thickness direction of the mobile terminal.

The first guide <NUM> may include a plate-shaped member protruding inward from the second side portion <NUM> of the second frame <NUM>, and the second guide <NUM> may have a shape surrounding an end of the first guide <NUM>. Because the second guide <NUM> of the form as shown in <FIG> increases in the volume, the second guide <NUM> may be formed in a U-shape surrounding the end of the first guide <NUM> to minimize the volume as shown in <FIG>.

The second guide may be formed in a form of defining a groove in the side portion of the first frame rather than being added to the first frame in a block form, so that the second guide may be extended long in the first direction like the first guide.

The first guide <NUM> may contain a metal material for rigidity, and the second guide <NUM> may contain a POM material to minimize friction with the first guide <NUM>.

The first guide <NUM> may be fastened through a screw <NUM> to the second side portion <NUM> of the second frame <NUM>, and may further include an alignment hole 231f for aligning a fastening position on the second frame <NUM> of the first guide <NUM> as shown in <FIG>.

In order to implement an antenna using the first side portion <NUM> or the second side portion <NUM> exposed to the outside, a feeding unit that feeds the antenna should be connected. Because the first side portion <NUM> is a portion of the first frame <NUM> in which the parts are mounted, it is easy to connect the feeding unit. However, because the first side portion <NUM> is covered by the second side portion <NUM>, it is preferable to use the second side portion <NUM> as the antenna. An antenna substrate <NUM> for connecting the second side portion <NUM> to the wireless communication unit of the first frame <NUM> may be disposed.

The antenna substrate <NUM> may be disposed to overlap the first guide <NUM> as shown in <FIG>. However, in the case in which the first guide <NUM> is made of the metal material, when the antenna substrate <NUM> is too close to a portion made of the metal used as the antenna of the second side portion <NUM>, there is a problem in that a performance of the antenna is deteriorated. Therefore, as shown in <FIG>, the antenna substrate <NUM> may be disposed to protrude a predetermined distance e outwardly of the first guide <NUM>.

<FIG> is an exploded perspective view showing the antenna substrate <NUM> and the first guide <NUM> according to an embodiment of a mobile terminal, and <FIG> is a diagram showing a state in which a side portion is separated according to an embodiment of a mobile terminal.

The antenna substrate <NUM> may be fastened through the screw <NUM> to the first guide <NUM>, and the first guide <NUM> and the antenna substrate <NUM> may have screw holes <NUM> and <NUM> through which the screw <NUM> passes, respectively. As shown in <FIG> and <FIG>, a connection pin 183c in contact with a metal portion of the second side portion <NUM> of the second frame <NUM> may be formed at an outer end of the antenna substrate <NUM>.

The linear guide <NUM> may have a guide roller <NUM> coupled to the first guide <NUM> as shown in <FIG> to prevent the second frame <NUM> from being tilted. In addition, because the guide roller <NUM> comes into contact with the third side surface 1023c while rotating, it is possible to reduce a frictional force generated when the second frame <NUM> slides.

<FIG> and <FIG> are diagrams showing the user input unit <NUM> according to an embodiment of a mobile terminal. As the size of the display unit <NUM> on the front surface of the mobile terminal <NUM> increases, the space for adding the user input unit <NUM> other than a touchpad to the front surface becomes insufficient. Instead, a button may be implemented in the lateral direction of the mobile terminal <NUM>.

An input through the touchpad of the display unit <NUM> is difficult for a key, such as a volume key, used in a state of not looking at the display unit <NUM>, or a key, such as a power button, for activating the mobile terminal in a state that the display unit <NUM> is turned off. Thus, it is preferable for such key to receive an input through the physical user input unit <NUM>.

It is inconvenient in terms of usability when the user input unit is located at a too high vertical level as shown in <FIG>, so that it is preferable to dispose the user input unit at the location where the first side portion <NUM> and the second side portion <NUM> overlap each other. That is, the user input unit may be located in the second side portion <NUM> or the user input unit may be located on the second side surface 1013b of the first side portion.

<FIG> shows an embodiment regarding the user input unit <NUM> located in the second side portion <NUM>, and <FIG> shows an embodiment regarding the user input unit <NUM> located on the second side surface 1013b.

The user input unit <NUM> in <FIG>, which is the user input unit <NUM> implemented in the side portion of the second frame <NUM>, may be seated by defining a groove <NUM> in the side portion of the second frame <NUM>. A switch board <NUM> having a dome switch <NUM> may be seated in the groove <NUM> of the side portion, a top button <NUM> may be overlapped with the dome switch <NUM>, and a button cover <NUM> having a hole defined therein corresponding to the top button <NUM> may be inserted into the side portion to fix the top button <NUM>.

When a thickness of the second side portion <NUM> is increased, there is a problem in that a height difference between the first side surface 1013a and the second side surface 1013b increases. Thus, the button cover <NUM> may be fixed at a location outward of the side portion to minimize the increase in the overall thickness of the second side portion <NUM> of the second frame <NUM>. When the second frame <NUM> moves in the first direction, a location of the user input unit <NUM> of such type also changes in the first direction.

The user input unit <NUM> in <FIG> is positioned on the second side surface 1013b of the first side portion <NUM> of the first frame <NUM>. Because the second side surface 1013b is covered by the second side portion <NUM> of the second frame, it is difficult to apply the user input unit <NUM> using the dome switch as in the embodiment in <FIG>.

Instead, a user input unit may be implemented using a force sensor <NUM>. The force sensor <NUM> is also referred to as a force touch and operates by recognizing a pressing force. As a sensor that generates an electrical signal in response to a minute mechanical change, the force sensor <NUM> may sense changes in a range from several um to tens of um on an attached surface.

The force sensor <NUM> does not need to be directly exposed to the outside, so that, even when the force sensor <NUM> is located inward of the first side portion <NUM>, the force sensor <NUM> may sense a pressure applied to an outer surface of the second side portion <NUM>. Deformation with a magnitude equal to or greater than a predetermined magnitude may be sensed as a user input and distinguished from a touch input occurring at a time of simple gripping.

Because the second side portion moves during the extension in the second state to expose the second side surface 1023b of the first side portion, a distance from a top of the user input unit may be kept the same as in the first state.

As described above, the mobile terminal of the present disclosure may adjust the size of the screen as needed, so that both portability and usability may be achieved.

Claim 1:
A mobile terminal comprising:
a first frame (<NUM>) comprising a front portion (<NUM>) and a rear portion (<NUM>); and
a second frame (<NUM>) couple with the first frame (<NUM>) to be capable of switching a state thereof to an extended state by moving in a first direction from the first frame (<NUM>), and to a contracted state by sliding in a second direction opposite to the first direction,
wherein the second frame (<NUM>) includes a rear portion (<NUM>) for at least partially covering a portion of the rear portion (<NUM>) of the first frame (<NUM>),
wherein the first frame (<NUM>) includes:
a first rear surface (1012a) being exposed to an outside rearwardly while in the contracted state and while in the extended state;
a second rear surface (1012b) located frontwardly of the rear portion (<NUM>) and not being exposed to the outside while in the contracted state, and wherein at least a portion of the second rear surface (1012b) is exposed to the outside rearwardly in the extended state; and
a third rear surface (1012c) covered by the rear portion (<NUM>) of the second frame (<NUM>) in both the contracted state and in the extended state,
wherein respective heights of the first rear surface (1012a), the second rear surface (1012b), and the third rear surface (1012c), are different; and
wherein the mobile terminal further comprises a display (<NUM>) including a fixed portion coupled to a front surface of the first frame (<NUM>) and a variable portion extending in the first direction from the fixed portion to surround the second frame (<NUM>) and bent toward the rear portion of the second frame (<NUM>)