Patent Description:
A display device is a device having a function of receiving, processing, and displaying a video that a user may watch. For example, the display device receives a broadcast selected by the user from broadcast signals transmitted from a broadcasting station, separates a video signal from the received signals, and displays the separated video signal on a display.

In recent years, because of a development of a broadcasting technology and a network technology, functions of the display device have also been considerably diversified, and a performance of the device has been improved accordingly. That is, the display device has been developed to provide not only broadcast contents but also various other contents to the user. For example, the display device may provide game play, music listening, internet shopping, user customized information, and the like using various applications as well as programs received from the broadcasting station. In order to perform such extended functions, the display device may be basically connected to other devices or networks using various communication protocols, and may provide the user with a ubiquitous computing environment. In other words, the display device has evolved into a smart device that enables connectivity to a network and continuous computing.

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. For the mobile terminal having such a variable structure, changing the size of the mobile terminal should be stably performed, and there is a need for a structure to support the extended display unit to maintain a flat state of the display unit.

<CIT>, <CIT>. <CIT>, <CIT> and <CIT> are documents of the related art.

An object of the present disclosure is to provide a mobile terminal that may be changed in size while maintaining a flat state.

The invention is defined in the independent claim. Dependent claims describe preferred embodiments. To achieve the above objects and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, a mobile terminal switchable from a first state to a second state by extending in the first direction may include a first frame, a second frame movable from the first frame in the first direction or a second direction opposite to the first direction, a slide frame movable in the first direction or the second direction with respect to the second frame, and a support link having one end hinged to the first frame and an opposite end hinged to the second frame, the support link having a variable length.

In the first state, the support link may be arranged such that the one end and the opposite end are positioned in a third direction perpendicular to the first direction, In the second state, the support link may be diagonally arranged with respect to the first direction and be elongated.

The mobile terminal may further include a plurality of rollers positioned an end of the second frame facing in the first direction and configured to rotate about an axis extending in the third direction, wherein, in the first state, the support link may be positioned between the plurality of rollers.

The mobile terminal may further include a flexible display including a first region coupled to the first frame, a second region coupled to the slide frame, and a third region positioned between the first region and the second region, the third region being bent to surround the second frame, and a roller coupled to one side of the second frame to rotate about an axis extending in the third direction perpendicular to the first direction, wherein the roller may include a plurality of mini-rollers respectively having a radius smaller than a radius of curvature of a curved portion of the display bent around the roller, the mini-rollers being disposed at a starting point, an end point, and an intermediate point of the curved portion of the display, wherein the support link may be disposed adjacent to the mini-rollers in the first state.

The support link may include a first link coupled to the first frame, and a second link coupled to the second frame, wherein the first link and the second link may be slide-coupled to each other.

The mobile terminal may further include a first link rail formed on one side of the first link or the second link and having a cross section of a T shape, and a second link rail formed on an opposite side of the first link or the second link and having a cross section surrounding the first link having a T shape.

Each of the first link and the second link may include a stop protrusion, the stop protrusions being fastened in the first state and the second state.

The second frame may include a front portion positioned on a front, and a rear portion positioned on a rear, wherein the first link and the second link may have a thickness corresponding to a distance between the front portion and the rear portion.

The mobile terminal may further include a driving unit arranged biased in a third direction perpendicular to the first direction and configured to move the second frame, wherein the driving unit may include a motor and a pinion gear positioned on the first frame, and a rack gear positioned on the second frame and configured to linearly move when the pinion gear rotates, wherein the support link may be positioned in a middle between the driving unit and an end facing in a fourth direction opposite to the third direction.

The second frame may include a front portion positioned on a front, a rear portion positioned on a rear, and a middle slot formed in the front portion and extending in the first direction, wherein the support link may be positioned on at least one side of the front portion partitioned by the middle slot.

The one end of the support link may be hinged to an end of the first frame facing in the first direction, and the opposite end of the support link may be hinged to an inner side of a side portion of the second frame, the side portion facing in the first direction.

In another aspect of the present disclosure, a mobile terminal switchable from a first state to a second state by extending in the first direction may include a first frame, a second frame movable from the first frame in the first direction or a second direction opposite to the first direction, a slide frame movable in the first direction or the second direction with respect to the second frame, and a flexible display including a first region coupled to the first frame, a second region coupled to the slide frame, and a third region positioned between the first region and the second region, the third region being bent to surround the second frame.

The first frame may include a front portion positioned on a front and coupled to the first region, a first rear portion positioned on a rear, a first side portion connected between the first front portion and the first rear portion and positioned on a periphery of the first frame except for a portion of the periphery facing in the first direction, and a middle fastening portion configured to fasten the first front portion and the first rear portion at ends thereof facing in the first direction, wherein the middle fastening portion may be positioned in a middle of a third direction perpendicular to the first direction.

The second frame may include a second front portion positioned on a rear side of the first front portion in the first state, a second rear portion positioned on a rear side of the first rear portion, the slide frame being positioned on the second rear portion, and a middle slot formed in the second front portion and extending in the first direction at a position corresponding to the middle fastening portion.

The mobile terminal of the present disclosure may allow the size of the screen to be adjusted as needed, thereby satisfying both portability and usability. In addition, the mobile terminal of the present disclosure may reduce the damage to the display unit caused by a concentrated stress because stress is not concentrated at a specific point.

In addition, a flat state may be maintained regardless of change in the state of the mobile terminal by preventing separation or sagging in the mobile terminal.

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.

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.

Suitable technologies for implementing such short-range communications include BLUETOOTHTM, Radio Frequency Identification (RFID), Infrared Data Association (IrDA), Ultra-WideBand (UWB), ZigBee, Near Field Communication (NFC), Wireless-Fidelity (Wi-Fi), Wi-Fi Direct, Wireless USB(Wireless Universal Serial Bus), 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> is a front view of a first state and a second state of the mobile terminal in accordance with an embodiment, and <FIG> is a rear view of the first state and the second state of the mobile terminal in accordance with an embodiment. <FIG> and <FIG> are views showing the first state in which the mobile terminal is contracted, and <FIG> and <FIG> are views showing the second state in which the mobile terminal is extended.

As shown in the figures, the mobile terminal <NUM> in the first state is in a contracted position, and has a smaller size than the mobile terminal <NUM> in the second state. In addition, the size of the display unit <NUM> positioned on the front of the mobile terminal <NUM> is also smaller than in the second state. The mobile terminal <NUM> in the first state may be extended in a first direction D1 to switch to the second state. In the second state, as shown in <FIG>, the size of the mobile terminal <NUM> and the size of the display unit <NUM> positioned on the front of the mobile terminal <NUM> are larger than in the first state, while the size of the display unit <NUM> positioned on the rear of the mobile terminal <NUM> is reduced as shown in <FIG>. That is, a part of the display units <NUM> positioned on the rear of the mobile terminal <NUM> in the first state moves to the front of the mobile terminal <NUM> in the second 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 D1, 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 D2. A direction perpendicular to the first and second directions D1 and D2 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.

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 be varied. 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 region 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 region 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 the 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>. Such operation will be described in more detail below along with other relevant components of the mobile terminal <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.

<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> corresponds to a main body of the mobile terminal <NUM>, and may have a space between the first front portion <NUM> and the first rear portion <NUM> therein for accommodating various components. 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, as shown in <FIG> and <FIG>, the first frame <NUM> may include a first front portion <NUM> disposed at a front portion of the mobile terminal <NUM> and supporting the front face of the display unit <NUM> and a first rear portion <NUM> disposed at a rear portion of the mobile terminal and on which various components are mounted. A front deco <NUM> may cover front edges of the first area 151a to protect the edges of the first area 151a.

The first front portion <NUM> and the first rear portion <NUM> may be spaced apart from each other at a predetermined spacing to define a predetermined space therebetween, and may be connected to each other by a first side portion <NUM>. The first side portion <NUM> may be integrally formed with the first rear portion <NUM> or the first front portion <NUM>. The camera <NUM>, the audio output module <NUM>, and the input/output terminal, the controller <NUM>, and the power supply unit <NUM> may be accommodated as components of the mobile terminal <NUM> in the space in the first frame <NUM>. For example, the controller <NUM> may be a circuit board <NUM> including a processor and an electronic circuit for controlling the operation of the mobile terminal, and the power supply unit <NUM> may be a battery <NUM> and related components. In addition, the driving unit <NUM> that controls the slide movement of the second frame <NUM>, which will be described later, may also 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 151a and 151b and a variable portion 151c. The fixed portion 151a and151b means a portion fixed to the frame. Because of being fixed to the frame, the fixed portion 151a and151b maintains a constant shape without changing a bending degree. On the other hand, the variable portion 151c means a portion in which a bending angle or a position of the bent portion changes. The variable portion 151c in which the position or bending angle of the bent portion changes requires a structure for supporting a rear face of the variable portion 151c in response to the change.

The fixed portion 151a, 151b is coupled to the first frame of the display unit and is always positioned on the front face of the display unit to form a portion of the front face of the display unit. The variable portion 151c 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 of the display unit and an area of a portion disposed on the rear face of the display unit vary. That is, a portion of the variable portion 151c may be the front face and another portion of the variable portion 151c may be the rear face based on the first and second states. The variable portion 151c is positioned in the first direction with respect to the fixed portion 151a, 151b relative to the mobile terminal, and an end of the variable portion 151c is bent toward the rear face of the mobile terminal and slides on the rear face of the second frame.

The end of the variable portion of the display unit is coupled with a slide frame that guides the variable portion to slide move on the rear face of the second frame, and the slide frame moves in the first direction at the same time as the second frame moves in the first direction. As a result, a moving distance of the slide frame with respect to the first frame is twice as a moving distance of the second frame with respect to the first frame. Further, as shown in <FIG>, the first rear portion <NUM> of the mobile terminal <NUM> includes an exposed rear portion <NUM> that is exposed to the outside without being covered by the display unit <NUM> even in the first state. The physical input unit <NUM> for the manipulation of the mobile terminal <NUM> such as various buttons, switches, the camera <NUM>, and a flash, and the sensing unit <NUM> such as the proximity sensor <NUM> or a fingerprint sensor may be arranged on the exposed rear portion <NUM>. The first rear portion <NUM> except for the exposed rear portion <NUM> may be covered by the display unit <NUM> in the first state as shown in <FIG>, and may be exposed rearward in the second state as shown in <FIG>.

In a conventional bar-shaped terminal, a display unit is provided only on a front face of the terminal. Therefore, a main camera is placed on a rear face of the terminal in order for the user to capture an object at an opposite side while looking through the display unit. On the other hand, an additional auxiliary camera is required to be disposed on the front face of the terminal in order for the user to capture himself or herself while viewing himself or herself through the display unit.

In the mobile terminal <NUM> of the present disclosure, on the other hand, the display unit <NUM> is arranged on both the front and rear of the mobile terminal <NUM>. Accordingly, when a user photographs himself, a portion of the display unit <NUM> positioned on the same surface as the camera <NUM>, that is, the rear face of the display unit <NUM> may be used. When the user takes a photograph of an object around the user, a portion of the display unit <NUM> on the side facing away from the camera <NUM>, that is, the front face of the display unit <NUM> may be used. For this reason, the mobile terminal <NUM> may take a photograph of the user or an object located around the user using one camera <NUM>. The camera may include a plurality of cameras having different angles of view, such as wide angle, ultra wide angle, and telephoto angle. Not only the camera but also a proximity sensor and an audio output unit may be disposed on the exposed rear portion <NUM>, and an antenna may be installed on the rear portion <NUM>. An exposed decor <NUM> may be used to protect the camera, the sensor, or the like on the exposed rear portion <NUM> and not to deteriorate the exterior design. A portion of the exposed decor <NUM> corresponding to the camera <NUM> or the sensor <NUM> may be configured to be transparent, and the other portion thereof may have a predetermined pattern or color in consideration of design aspects without exposing internal parts.

The first side portion <NUM> may extend along the edges of the first front portion <NUM> and the first rear portion <NUM> to surround the circumference of the first frame <NUM> and may define the appearance of the mobile terminal <NUM>. However, as mentioned above, the second frame <NUM> is accommodated in and movably coupled to the first frame <NUM>, and therefore a portion of the first frame <NUM> needs to be open to allow movement of the second frame <NUM> relative to the first frame <NUM>. As an example, as best shown in <FIG>, the second frame <NUM> may be movably coupled to a side of the first frame <NUM> facing in the first direction, and accordingly the first side portion <NUM> may not be formed on the lateral surface facing in the first direction such that the lateral surface is open. Since 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 or the user input unit <NUM>, such as a volume control button, may be disposed on the first side portion <NUM>. 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 <NUM> disposed at the front portion of the mobile terminal <NUM> and a second rear portion <NUM> disposed at the rear portion 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 <NUM> and the second rear portion <NUM> may be formed of plate-shaped members that are generally flat. In addition, the second frame <NUM> also accommodates various components, and must not interfere with the components accommodated in the first frame <NUM> during the movement. Accordingly, the second front portion <NUM> and the second rear portion <NUM> may be coupled to each other in a state of being spaced apart from each other to define a predetermined space therebetween, and may have shapes that do not interfere with the components in the first frame <NUM>.

<FIG> is a side view of the mobile terminal as viewed from a third direction. <FIG> shows the first side portion <NUM> of the first frame <NUM> and a second side portion <NUM> of the second frame <NUM>. Since the flexible display unit <NUM> is positioned at an end of the second frame <NUM> facing in the first direction, the end of the second frame <NUM> facing in the first direction should not be exposed to the outside. An end of the second frame <NUM> facing in the second direction should be open so as not to interfere with the first frame <NUM>. In the first state, the second side portion <NUM> of the second frame <NUM>, which is positioned on the side facing in the third direction (which refers to the upward or downward direction in the drawing or may include both the upward and downward directions), may not be exposed to the outside because it overlaps the first side portion <NUM> of the first frame. However, in the second state, it may be exposed to the outside because the second frame <NUM> is drawn out.

In addition, the display unit <NUM> may be bent <NUM> degrees while being rolled in the second frame <NUM> to be disposed on both the front face and the rear face of the mobile terminal <NUM>. For such an arrangement of the display unit <NUM>, the second frame <NUM> may include a roller <NUM> rotatably disposed therein. The roller <NUM> may be disposed at any position inside the second frame <NUM>. However, the display unit <NUM> should be spread flat on the front face and the rear face of the mobile terminal <NUM> to provide a good quality screen to the user. Further, for such spread, a proper tension must be provided on the display unit <NUM>. In order to provide the proper tension, the roller <NUM> may be disposed at a first directional end of the second frame <NUM>. The roller <NUM> may extend in the third direction, and may be rotatably coupled to the second frame <NUM>.

The display unit <NUM> may be rolled around the roller <NUM> while being gently bent with a predetermined curvature. The flexible display unit <NUM> may include a first face on which a video is output and exposed to the outside and an inner face facing the frame at the opposite side. The roller <NUM> may be installed to rotate freely in the second frame <NUM> while being in contact with the inner face of the display unit <NUM>. Accordingly, the roller <NUM> 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, because of the tension applied by the second frame <NUM>, the display unit <NUM> moves to the front face or the rear face of the mobile terminal <NUM> in different directions (i.e., the first direction D1 or the second direction D2) relative to the second frame <NUM>. The roller <NUM> may guide such movement while rotating.

The roller <NUM> may be disposed adjacent to the end of the second frame <NUM> that faces in the first direction. A side frame <NUM> may be disposed at the end of the second frame <NUM> facing in the first direction to prevent damage to the display unit <NUM> rolled around the roller <NUM>.

The side frame <NUM> may extend in the longitudinal direction (the third direction) of the second frame <NUM> to cover the side portion facing in the first direction, thereby protecting the roller <NUM> and the display unit <NUM> rolled therearound.

And the position thereof may vary depending on the state of the mobile terminal. Since the side portion is rolled by the roller, the side portion may be curved to have a predetermined curvature, and the inner surface of the side frame may include a curved surface corresponding to the curvature of the side portion.

The side frame <NUM> may substantially define the appearance of the mobile terminal <NUM> in cooperation with the first side portion <NUM> of the first frame <NUM>. In addition, the side portion of the second frame <NUM> that faces in the second direction may be omitted to minimize interference with the components arranged in the first frame <NUM> during movement.

During the expansion and the contraction in such first and second directions D1 and D2, the second frame <NUM> may overlap the first frame <NUM>, more precisely, the first front portion <NUM> and the first rear portion <NUM> thereof so as not to interfere with the first frame <NUM>. More specifically, the display unit <NUM> may be coupled to and supported by the first front portion <NUM> of the first frame <NUM>, as described above. Accordingly, the display unit <NUM> does not need to be additionally supported by the second front portion <NUM> of the second frame <NUM>. Rather, when the second front portion <NUM> is interposed between the first front portion <NUM> and the display unit <NUM>, the display unit <NUM> may be deformed or damaged because of friction with the second front portion <NUM>, which is repeatedly moved. Thus, the second front portion <NUM> may be disposed below the first front portion <NUM>, or may be interposed between two first front portions <NUM>. The second rear portion <NUM> of the second frame <NUM> may be disposed rearward of the first rear portion <NUM> of the first frame <NUM>. That is, the front face of the second rear portion <NUM> may face the rear face of the first rear portion <NUM>. In addition, the rear face of the first rear portion <NUM> may be in contact with the front face of the second rear portion <NUM> to stably support the movement of the second frame <NUM>. Because of 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 contract in the first and second directions D1 and D2 to change the size of the mobile terminal <NUM>, particularly, to extend or contract the front face of the mobile terminal <NUM>. Thus, the display unit <NUM> must move by such extended or reduced front face size to obtain the intended first and second states. However, when being fixed to the second frame <NUM>, the display unit <NUM> may not be moved smoothly to be adapted for the front face of the mobile terminal <NUM> that is extended or contracted. For this reason, the display unit <NUM> may be movably coupled to the second frame <NUM>.

More specifically, the display unit <NUM> may include a first region 151a disposed on the front of the mobile terminal <NUM>, a second region 151b coupled to a slide frame <NUM> positioned on the rear of the mobile terminal <NUM>, and a third region 151c located between the first region 151a and the second region 151b and bent around the roller <NUM>. The third region 151c may move to the front or the rear according to change in the state of the mobile terminal <NUM>. The slide frame <NUM> may be formed of a plate-shaped member extending in the longitudinal direction (the third direction) of the mobile terminal <NUM>.

The slide frame <NUM> may be coupled to the second rear portion <NUM> so as to be movable in the first and second directions D1 and D2.

The first to third regions 151a, 151b, and 151c may be connected to each other, and may form a continuous body of the display unit <NUM>. In addition, as described above, for the movement of the third region 151c toward the front face or the rear face of the mobile terminal <NUM> depending on the moving direction of the second frame <NUM>, the first region 151a may be fixed so as not to move to the front face of the mobile terminal <NUM>, and the second region 151b may be provided to be movable on the rear face of the mobile terminal. Such configuration of the display unit <NUM> will be described in more detail below.

The first region 151a may be disposed on the front face of the mobile terminal <NUM>, more specifically, the first frame <NUM>, that is, on the front face of the first front portion <NUM>. The first region 151a is fixed to the first frame <NUM>, that is, the front face of the first front portion <NUM> so as not to be moved during the movement of the second frame <NUM>, and thus, the first region 151a may always be exposed to the front face of the mobile terminal <NUM>.

The third region 151c may be adjacent to the first region 151a in the first direction and rolled on the roller <NUM>. The third region 151c may partially cover the second frame <NUM>, that is, the rear face of the second rear portion <NUM>. Further, the second frame <NUM>, that is, the second rear portion <NUM>, is adjacent to the first frame <NUM>, that is, the first rear portion <NUM> and together forms the rear case of the mobile terminal <NUM>. Accordingly, it may be described that the third region 151c is also disposed on the rear face of the first frame <NUM>.

The second region 151b may be adjacent to the third region 151c and may be disposed on the rear face of the mobile terminal <NUM>, more specifically, on the second frame <NUM>, that is, the rear face of the second rear portion <NUM> thereof. The second region 151b may be coupled to the slide frame <NUM> without being directly coupled to the second frame <NUM>.

As a result, the first region 151a may be disposed on the front face of the mobile terminal <NUM> and may be always exposed to the front face regardless of the movement of the second frame <NUM>, and the second region 151b may be disposed on the rear face of the mobile terminal <NUM> and may be always exposed to the rear face regardless of the movement of the second frame <NUM>. In addition, the third region 151c may be disposed between the first and second regions 151a and 151b, and may be selectively placed on the front face or the rear face of the mobile terminal <NUM> depending on the moving directions D1 and D2 of the second frame <NUM>.

Because of such selective placement of the third region 151c, the first rear portion <NUM> of the first frame <NUM> may be exposed to the outside of the mobile terminal <NUM> because the first rear portion <NUM> is covered by the second and third regions 151b and 151c and the second rear portion <NUM> of the display unit <NUM> in the first state, but, in the second state, the third region 151c moves to the front face of the mobile terminal <NUM> and the second rear portion <NUM> also moves in the first direction D1. In addition, the second front portion <NUM> of the second frame <NUM> is hidden by the first front portion <NUM> of the first frame <NUM> in the first state, but, in the second state, moves out of the first frame <NUM> to support the third region 151c of the display unit <NUM> disposed on the front face of the mobile terminal <NUM>.

In order to prevent the second front portion <NUM> from affecting the internal components during the slide movement, a separating plate <NUM> may be further disposed rearward of the second front portion <NUM> and fastened with the first front portion <NUM>. The second front portion <NUM> may move between the first front portion <NUM> and the separating plate <NUM> based on the slide movement of the second frame.

However, the third region 151c may be rolled on the roller <NUM> and bent in the second frame <NUM>. When converting from the first state to the second state, the third region 151c may extend from the second frame <NUM> to the front face of the mobile terminal <NUM> while being rolled on the roller <NUM> in one direction. On the other hand, when converting from the second state to the first state, the third region 151c may be retracted from the front face of the mobile terminal <NUM> to the second frame <NUM> while being rolled on the roller <NUM> in the opposite direction, and at the same time, may return to the rear face of the mobile terminal <NUM> from the second frame <NUM>.

A specific location of the foldable mobile terminal in a form of being spread like a book is easily damaged because only the specific location is folded repeatedly. On the other hand, the deformed portion of the flexible display unit <NUM>, that is, a portion rolled on the roller <NUM>, may vary based on the first and second states of the mobile terminal <NUM>, that is, the movement of the second frame <NUM>. Accordingly, the mobile terminal <NUM> of the present disclosure may significantly reduce deformation and fatigue repeatedly applied to a specific portion of the display unit <NUM>, thereby preventing damage to the display unit <NUM>.

Based on the above-described configuration, overall operations of the mobile terminal <NUM> will be described as follows. As an example, the state conversion may be performed manually by the user, and an operation of the mobile terminal <NUM> during such manual state conversion will be described. However, operations of the first to third frames <NUM> to <NUM> and the display unit <NUM>, which will be described below, may be performed in the same manner when a power source other than a user's force is used, for example, when the driving unit <NUM> to be described below is applied.

A rear face cover <NUM> may be further disposed on a rear face of the second rear portion <NUM> such that the rear face of the display unit positioned on the rear face of the mobile terminal <NUM> is not exposed to the outside. The rear face of the display unit may be used in the first state when the rear face cover <NUM> uses a transparent material, and the rear face of the display unit may be covered such that the movement of the slide frame <NUM> is not exposed when the rear face cover <NUM> uses an opaque material. That is, the second region and the third region of the slide frame <NUM> and the display unit <NUM> may move in the first direction and in the second direction in a space between the second rear portion <NUM> and the rear face cover <NUM>.

<FIG> is a view showing a driving unit <NUM> of the mobile terminal <NUM> in accordance with an embodiment. The mobile terminal <NUM> of the present disclosure may be switched between the states in a manner in which a user manually pulls the second frame <NUM> in the first direction or pushes the same in the second direction with respect to the first frame <NUM>. However, in the manual method, applying excessive force to the body of the mobile terminal <NUM> may damage the mobile terminal <NUM>. Accordingly, a driving unit <NUM> employing a motor <NUM> may be further provided to allow the second frame <NUM> to stably move without distortion.

As the motor <NUM>, a motor <NUM> configured to provide rotational force as shown in <FIG>, or a linear motor <NUM> configured to make linear motion may be used. The motor <NUM> configured to provide the rotational force may need to have a large diameter to provide large force. However, in order to provide driving force of a predetermined magnitude or more in the limited space of the mobile terminal <NUM> without increasing the thickness, two motors <NUM> may be used as shown in <FIG>. If the second frame <NUM> is moved excessively fast, damage or malfunction may occur. Accordingly, a planetary gear configured to decrease the speed of the motor <NUM> to ensure movement at a stable speed may be further provided. The planetary gear <NUM> serves to amplify or attenuate the number of revolutions of the motor <NUM> using a plurality of disc gears having different numbers of teeth. The motor <NUM> may be fixed to the first frame <NUM> as shown in <FIG>. The position of the motor <NUM> is fixed even when the second frame <NUM> moves in the first direction to switch the mobile terminal <NUM> to the second state, as shown in <FIG>.

Since the second frame <NUM> linearly moves with respect to the first frame <NUM> in the first direction or the second direction, rack and pinion gears configured to convert the rotational force of the motor <NUM> into linear motion may be used. A pinion gear to receive the rotational force of the motor <NUM> may be arranged to engage with a rack gear <NUM> composed of teeth continuously arranged in the first direction. The pinion gear may be fixed to the first frame <NUM> together with the motor <NUM> and the rack gear <NUM> may be positioned on the second frame <NUM>. Alternatively, the rack gear <NUM> may be positioned on the first frame <NUM>, and the motor <NUM> and the pinion gear may be arranged on the second frame <NUM>. Since the motor <NUM> holds the pinion gear such that the pinion gear does not rotate, the second frame <NUM> may maintain the first state and the second state. However, when large external force is applied, the second frame <NUM> may be displaced as the pinion gear rotates.

A stopper (not shown) configured to fix the positions of the second frame <NUM> or the rack gear <NUM> and the first frame <NUM> may be further provided to fix the mobile terminal <NUM> in the first state or the second state. When electric current flows through the motor <NUM> to drive the motor <NUM>, the stopper may be released to allow the movement of the second frame <NUM>. When power is not applied to the motor <NUM> and thus the motor <NUM> does not rotate, the first frame <NUM> and the second frame <NUM> may be fastened such that the positions thereof are fixed.

When a pair of driving units <NUM> is symmetrically disposed in the vertical direction (the third direction), stable movement may be made. However, to arrange a battery or the like, the driving unit <NUM> should be arranged biased to one side in consideration of the limited mounting space of the mobile terminal 100as shown in <FIG>. According to such asymmetric arrangement of the driving unit <NUM>, the second frame <NUM> may be distorted during movement due to a difference in movement speed between the upper end portion and the lower end portion. To address this issue, a linear guide <NUM> may be further provided.

The linear guide <NUM> may be disposed at both ends of the mobile terminal <NUM> facing in the third direction, that is, on the upper and lower sides of the mobile terminal <NUM>, in order to supplement the function of one driving unit <NUM> biased to one side in the third direction. The linear guide <NUM> may include a guide rail <NUM> extending in the first direction and a guide block <NUM> configured to move along the guide rail <NUM>. The guide rail <NUM> may be disposed on the first frame <NUM> and the guide block <NUM> may be disposed on the second frame <NUM>, or vice versa. In this embodiment, the guide rail <NUM> may be disposed on the second frame <NUM> to cover the upper and lower sides of the extended portion of the second frame <NUM> in the second state.

After the guide block <NUM> is coupled to the first frame <NUM> and the guide rail <NUM> is coupled to the second frame <NUM>, the guide block <NUM> and the guide rail <NUM> may be slidably fastened to each other. However, for convenience of the fastening, the guide block <NUM> and the guide rail <NUM> fastened to each other. Then, the guide block <NUM> may be first fixed to the first frame <NUM>, and then the second frame <NUM> may be coupled to the guide rail <NUM>.

The guide block <NUM> may be provided with a guide groove into which the guide rail <NUM> is inserted. Alternatively, the guide rail <NUM> may be provided with a rail groove into which a portion of the guide block <NUM> is inserted. The fastening portions of the guide rail <NUM> and the guide block <NUM> may be formed to be bumpy. Accordingly, movement in the first direction or the second direction may be made without displacement in the thickness direction of the mobile terminal <NUM>. In order to reduce friction between the guide block <NUM> and the guide rail <NUM>, a self-lubricating member having high wear resistance and low friction resistance, such as a bearing or polyoxymethylene (POM), may be added to the inside of the guide groove.

<FIG> is a cross-sectional view taken along lines A-A and B-B in <FIG>. As illustrated in <FIG>, when the second frame <NUM> switches to the second state by moving in the first direction, the third region 151c positioned on the rear side moves to the front, and thus a structure to support the rear surface of the third region 151c moved to the front is required. The second front portion <NUM> positioned on the front surface of the second frame <NUM> may be positioned on the rear surface of the third region 151c in the second state. However, in the first state, the second front portion <NUM> is disposed to overlap the first front portion <NUM> of the first frame <NUM>, and accordingly the first front portion <NUM> and the second front portion <NUM> form a step. A boundary is formed between the first region 151a and the third region 151c of the flexible display unit <NUM> by the step formed by the first front portion <NUM> and the second front portion <NUM>. A rolling plate <NUM> may be used as a support structure to fill the gap between the second front portion <NUM> and the third region 151c of the flexible display unit <NUM>.

The rolling plate <NUM> may be positioned on the rear surface of the flexible display unit <NUM>, and have a thickness corresponding to the gap between the second front portion <NUM> and the flexible display unit <NUM> in the second state. As shown in <FIG>, in the first state, the rolling plate <NUM> is rolled around the roller <NUM> and is positioned on the lateral side and rear side of the mobile terminal <NUM>. The flexible display unit <NUM> and the rolling plate <NUM> may be positioned between the second rear portion of the second frame <NUM> and a rear cover <NUM> provided to cover the rear face of the display unit <NUM>. As shown in <FIG>, when switch to the second state occurs, the rolling plate <NUM> may move to the front and the rolling plate <NUM> may be positioned on the front portion of the second frame <NUM>.

The third region 151c of the display unit <NUM> in which the rolling plate <NUM> is positioned is a portion where bending deformation occurs when switch from the first state to the second state occurs. Accordingly, the rolling plate <NUM> may be deformed according to deformation of the third region 151c. Here, the rolling plate <NUM> is required to have a predetermined stiffness to maintain the flat state when the flexible display unit <NUM> is positioned on the front or rear of the mobile terminal. That is, the rolling plate <NUM> needs a structure capable of maintaining the flat state in the third direction and performing bending deformation in the first direction.

<FIG> is a view illustrating a rolling plate <NUM> of the mobile terminal <NUM> in accordance with an embodiment. The rolling plate <NUM> may include multiple support bars <NUM> extending in the third direction. The multiple support bars <NUM> may be arranged side by side in the first direction and spaced apart from each other by a predetermined distance. Accordingly, even when the flexible display unit <NUM> is rolled around the roller <NUM> and is thus bent, interference between the support bars <NUM> may be avoided. The support bars <NUM> may be implemented with an injection molding material having a predetermined thickness for stiffness, and may contain a material such as special use steel (SUS), ferrosilicon (FeSi), liquid metal, or amorphous metal.

Ferrosilicon is an alloy of iron and silicon. Ferrite is a type of ferrosilicon. Since ferrosilicon is magnetic, it may serve to prevent magnetic force from penetrating the mobile terminal.

Liquid metal is a new alloy material formed by mixing zirconium with titanium, nickel, and copper, and the surface thereof is smooth like a liquid. Liquid metal is lighter than iron, and the strength thereof is three or more times that of the iron. At high temperatures, it may be freely molded into a desired shape like plastics and may be implemented to be thin compared to the strength thereof.

Amorphous metal refers to a metal having an irregular atomic arrangement. A typical metal has a crystalline structure in which atoms are regularly arranged. When the typical metal changes to a liquid phase at a high temperature, the typical metal becomes amorphous as the arrangement thereof collapses. When the typical metal is cooled at a normal rate, it returns to the original crystalline structure. However, when it is rapidly chilled, the typical metal is hardened in the amorphous state, obtaining better tensile strength and better abrasive and magnetic properties than metals having a crystalline structure.

The multiple support bars <NUM> may be directly attached to the rear surface of the display unit <NUM>. However, this operation may take a long time and produce a lot of defects, resulting in poor productivity. In addition, directly processing the display unit <NUM> is highly likely to damage the display unit <NUM>. Therefore, a rolling sheet <NUM> to fix the multiple support bars <NUM> may be further provided. The rolling sheet <NUM> may include a metal material, and may employ a superelastic material that is bending-deformable and capable of recovering the flat state after the bending deformation. For example, a superelastic metal sheet such as a thin STS sheet of <NUM> or less may be used. An adhesive tape <NUM> may be attached to both surfaces of the rolling sheet <NUM> to bond the rolling sheet <NUM> to the support bars <NUM> and bond the rear surface of the display unit <NUM> to the rolling sheet <NUM>.

The rolling sheet <NUM> may be provided with a kerf pattern in which multiple grooves extending in the third direction are formed in the first direction. The grooves in the kerf pattern may be formed between the multiple support bars <NUM>. The grooves may be formed on a surface of the rolling sheet <NUM> to which the support bars <NUM> are bonded. The kerf pattern may be formed in a wedge shape so as to be gradually narrowed from the surface portion of the rolling sheet <NUM>.

Alternatively, multiple holes extending in the third direction and arranged zigzagged in the first direction may be formed in the rolling sheet <NUM> such that bending deformation is more easily performed in the first direction.

Instead of the rolling sheet <NUM>, an elastic material such as silicone may be disposed between the support bars <NUM> to join neighboring support bars <NUM>. In this case, the angle between the support bars <NUM> may be varied. The elastic connector may be bent at a position corresponding to the roller <NUM>. When positioned on the front or rear of the mobile terminal, the elastic connector may be unfolded such that the support bars <NUM> are disposed forming a flat surface.

The support bars <NUM> may form a flat surface corresponding to the rear surface of the display unit <NUM>. Alternatively, as shown in <FIG>, the support bars <NUM> may be formed in a shape having a predetermined curvature. The curved support bars <NUM> may closely contact the curved surface of the roller <NUM> when the rolling plate <NUM> is rolled around the roller <NUM>. Alternatively, one surface of the support bars <NUM> in contact with the display unit <NUM> maintains a flat state, and the other surface thereof on the opposite side may include a curved surface corresponding to the curvature of the roller <NUM>. In this case, the support bars <NUM> may be thick at the ends thereof facing in the first and second directions and have the thinnest portion in the middle thereof.

The rolling plate <NUM> may be disposed at a position corresponding to the third region 151c and is rolled and bent around the roller <NUM>. Thus, the rolling plate <NUM> may span over the front and rear surfaces. The rolling plate <NUM> is connected to the first front portion <NUM> of the first frame <NUM> on the front side and connected to the slide frame <NUM> on the rear side. In order for the flexible display unit <NUM> to form a continuous surface without a step, the first front portion <NUM> of the first frame <NUM> positioned on the rear surface of the first region 151a, the slide frame <NUM> positioned on the rear surface of the second region 151b, and the rolling plate <NUM> positioned on the rear surface of the third region 151c may be arranged such that the surfaces thereof in contact with the display unit <NUM> are at the same height.

In particular, since the slide frame <NUM> moves on the rear of the mobile terminal <NUM> and moves in the same space as the rolling plate <NUM>, the rolling plate <NUM> may have a thickness corresponding to the thickness of the slide frame <NUM>.

<FIG> is a view showing the first frame <NUM> and the second frame <NUM> in the first state and the second state of the mobile terminal <NUM>, and <FIG> is a cross-sectional view taken along lines C-C and D-D of <FIG>. The first frame <NUM> and the second frame <NUM> are arranged overlapping each other in the first state. In the second state, the second frame <NUM> is moved, and thus the area thereof overlapping the first frame <NUM> is minimized.

As described above, the first frame <NUM> includes a first front portion <NUM> positioned on the front, a first rear portion <NUM> positioned on the rear, and a first side portion <NUM> positioned between the first front portion <NUM> and the second front portion <NUM> and configured to define a side appearance. The first side portion <NUM> may be formed in a square bracket shape surrounding the mobile terminal <NUM> except for an end portion of the mobile terminal <NUM> facing in the first direction. The second frame <NUM> is coupled to the end portion of the mobile terminal <NUM> facing in the first direction. When the display unit is bent at an end portion facing in the second direction, the thickness of the first side portion <NUM> in the second direction may be less than the thickness of the first side portion facing in the third direction or the fourth direction (the vertical direction).

The second frame <NUM> may include a second front portion <NUM>, a second rear portion <NUM>, and a second side portion. A part of the second side portion <NUM> facing in the second direction is omitted to overlap the first frame <NUM>. Parts of the second side portion <NUM> facing in the third direction and the fourth direction may be disposed inside the first side portion <NUM> inside of the first frame <NUM>. Since the display unit <NUM> is positioned on a part of the second side portion <NUM> facing in the first direction, a roller may be disposed at the end of the second frame <NUM> facing in the first direction and the part of the second side portion <NUM> facing in the first direction may be omitted. In order to protect the bent portion of the display unit <NUM>, a side frame <NUM> that is to be coupled to the second frame <NUM> to cover the bent portion of the display unit <NUM> may be further provided.

A separation plate <NUM> may be further provided to support the rear surface of the second front portion <NUM> of the second frame <NUM> in the first state and to protect the components mounted in the first frame <NUM> according to driving of the second front portion <NUM> of the second frame <NUM>. The separation plate <NUM> may be configured to have an opening partially formed to minimize the weight as illustrated in <FIG>.

<FIG> and <FIG> show only the second front portion <NUM>, omitting the second rear portion <NUM> and the second side portion of the second frame <NUM>. <FIG> and <FIG> illustrate the first state, and <FIG> and <FIG> illustrate the second state.

Referring to <FIG> and <FIG>, in the first state, the display unit (not shown), the first front portion <NUM>, the second front portion <NUM>, the separation plate <NUM>, the first rear portion <NUM>, and the second rear portion <NUM> (not shown) are arranged from the front, and components such as the battery <NUM> and the printed circuit board <NUM> are disposed between the separation plate <NUM> and the first rear portion <NUM>.

The second front portion <NUM> may be positioned between the first front portion <NUM> and the separation plate. When the mobile terminal switches to the second state, the second front portion <NUM> may be drawn out of the space between the first front portion <NUM> and the separation plate and moved in the first direction, as shown in <FIG> and <FIG>.

The first front portion <NUM> is separated from the separation plate and the first rear portion <NUM> by the second front portion <NUM>. As shown in <FIG>, the length of the second front portion <NUM> in the third direction may be formed to be less than that of the first frame <NUM>, such that the first front portion <NUM> may be coupled to the first rear portion <NUM> at the end facing in the third direction by fastening members S1 and S3 such as screws. However, as shown in <FIG> and <FIG>, it is difficult to fasten the first front portion <NUM> and the first rear portion <NUM> at the middle portion of the mobile terminal <NUM> in the third direction, and accordingly separation may occur on the front of the mobile terminal <NUM>.

In the first state, the second front portion <NUM> does not sag because the separation plate <NUM> and the components mounted in the first frame <NUM> are positioned on the rear of the second front portion <NUM>. However, in the second state, the second front portion <NUM> may sag rearward as shown in <FIG> and <FIG>. An end of the second front portion facing in the third direction may not be bent because it is supported by the second side portion <NUM>. However, the middle portion of the second front portion <NUM> needs a support structure.

<FIG> is a view showing a first frame <NUM> and a second frame <NUM> provided with a middle fastening portion S2 and a middle slot <NUM>. <FIG> is an enlarged view of parts E to G of <FIG>, and <FIG> is a cross-sectional view taken along lines H-H and I-I of <FIG>.

In this embodiment, unlike the embodiment of <FIG> described above, the first front portion <NUM> and the first rear portion <NUM> are fastened to the middle portion in the third direction to prevent the first front portion <NUM> from being bent forward. As illustrated in <FIG>, the ends of the first front portion <NUM> and the first rear portion <NUM> facing in the third and fourth directions may be fastened using the fastening members S1 and S3.

The middle fastening member S2 positioned in the middle may be arranged through the second front portion <NUM> to fasten the first front portion <NUM> and the second rear portion <NUM>. A middle slot <NUM> extending in the first direction may be formed in the first front portion <NUM> to prevent the middle fastening member S2 from obstructing the second frame <NUM> from moving in the first direction. At least one end of the middle slot <NUM> may be closed to prevent the second front portion <NUM> from being divided into two pieces due to the middle slot <NUM>.

The first front portion <NUM> may be fastened to the first rear portion <NUM>, and thus the first front portion <NUM> may be prevented from being bent forward. However, it is still difficult to address the issue of rearward bending of the second rear portion <NUM> in the second state. In particular, when the middle slot <NUM> is formed, the force to support the second front portion <NUM> may become weaker, and thus rearward bending may occur at the position where the middle slot <NUM> is formed.

In the portion provided with the driving unit <NUM>, the rack gear <NUM> of the driving unit <NUM> may be coupled to the second front portion <NUM> of the second frame <NUM>, thereby enhancing the rigidity of the second front portion <NUM>. However, since the driving unit <NUM> is disposed biased in the third direction to mount components such as the battery <NUM>, bending deformation of the second front portion <NUM> may still occur at a position spaced apart from the driving unit <NUM>.

In order to address the above-mentioned issue, a support link <NUM> may be further provided. <FIG> is a view showing the interior of a mobile terminal <NUM> including the support link <NUM>. <FIG> is a view showing the support link <NUM>, and <FIG> is a view showing the arrangement of the support link <NUM> according to the state of the mobile terminal <NUM>.

The support link <NUM> has one end coupled to the first frame <NUM>, and an opposite end coupled to the second frame <NUM>. Both ends are rotatably hinged. The angle of the hinged ends of the support link <NUM> with respect to the first frame <NUM> and the second frame <NUM> may vary, and thus the arrangement thereof may differ between the first state and the second state.

As shown in <FIG>, in the first state, the support link <NUM> is disposed to extend in the third direction. In the second state, the support link <NUM> is obliquely disposed with respect to the first direction and the third direction. In the first state, the support link <NUM> is interposed between the end of the first frame <NUM> facing in the first direction and the inner side of the side portion of the second frame <NUM> facing in the first direction.

In the second state, the second frame <NUM> is spaced apart from the first frame <NUM>, and accordingly the opposite end of the support link <NUM> moves according to the distance the second frame <NUM> moves. When the support link <NUM> is switched from the first state to the second state, the positions on the first frame <NUM> and the second frame <NUM> to which the support link <NUM> is coupled do not change, and accordingly the length thereof may change to compensate for the change according to the distance that the second frame <NUM> moves.

In the second state, the length of the support link <NUM> is changed to the length of the diagonal of a right-angled triangle having the length of the support link <NUM> in the first state and the distance that the second frame <NUM> has moved as two sides.

The support link <NUM> may include a first link <NUM> having one end hinged to the first frame <NUM>, and a second link <NUM> slide-coupled to the first link <NUM> and having an opposite end coupled to the second frame <NUM>. When the degree of overlapping of the first link <NUM> and the second link <NUM> is changed, the overall length of the support link <NUM> may be changed.

A first link rail <NUM> having a T-shape and a second link rail <NUM> having a C shape surrounding the T shape of the first link rail <NUM> may be provided to allow the first link <NUM> and the second link <NUM> to move only in the longitudinal direction and to prevent the first link <NUM> and the second link <NUM> from slipping in a direction in which the first link <NUM> and the second link <NUM> face each other or the thickness direction of the mobile terminal <NUM>.

The first link rail <NUM> and the second link rail <NUM> may be disposed on the first link <NUM> or the second link <NUM>, respectively, to guide the slide movement of the first link <NUM> and the second link <NUM> only in the longitudinal direction of the support link <NUM>.

The support link <NUM> may maintain the length thereof in the first state or the second state such that the mobile terminal is fixed in the first state or the second state. A stop protrusion <NUM> and a stop groove <NUM> may be provided to the first link <NUM> and the second link <NUM>. The stop protrusion <NUM> and the stop groove <NUM> may be fastened to each other in the first state or the second state to maintain the length of the support link <NUM>. The stop protrusion <NUM> and the stop groove <NUM> may include a curved surface. The stop protrusion <NUM> and the stop groove <NUM> may remain in a fastened state when subjected to force less than a reference and may release from each other and allow the length of the support link <NUM> to be changed when force greater than or equal to the reference is applied thereto.

The support link <NUM> may have a thickness corresponding to the distance between the second front portion <NUM> and the second rear portion <NUM> and support the second front portion <NUM>. The first support link <NUM> and the second support link <NUM> should have the same thickness to stably support the second front portion <NUM> even in the second state.

The support link <NUM> arranged in the diagonal direction may support the rear surface of the second front portion <NUM>. It may support the rear surface at various positions along the first direction and the third direction. In particular, the support link <NUM> may be positioned on the opposite side to the rack gear <NUM> of the driving unit <NUM> with respect to the middle slot <NUM> to reinforce a support portion that is weak to support the second front portion <NUM>.

The support link <NUM> may be arranged in the middle of the space between the rack gear <NUM>, which is biased in the third direction, and an end of the second frame <NUM> facing in the fourth direction, force to support the rear of the second front portion <NUM> may be more uniformly provided.

In the first state, the support link <NUM> is arranged to extend in the third direction. In this regard, to minimize the space occupied by the support link <NUM>, the support link <NUM> may be disposed between multiple rollers <NUM> coupled to the second frame <NUM>. A single roller <NUM> having a length corresponding to the length of the mobile terminal <NUM> in the third direction may be employed. However, in consideration of the arrangement of components such as the driving unit <NUM>, the multiple rollers <NUM> may be arranged spaced apart from each other in the third direction.

Disposing the support link <NUM> in the space between the rollers <NUM> may eliminate the need to secure additional space between the first frame <NUM> and the second frame <NUM> for arrangement of the support link <NUM> in the first state. Accordingly, the increase in size of the mobile terminal <NUM> according to addition of the support link <NUM> may be minimized.

<FIG> is a view showing the arrangement of a support link and a roller in accordance with another embodiment. The roller <NUM>' of this embodiment includes a mini-roller <NUM> having a smaller diameter. While the roller <NUM> described above has a curvature corresponding to the bending curvature of the display unit <NUM>, the roller <NUM>' of this embodiment may employ a mini-roller <NUM> having a radius smaller than the radius of curvature of the display unit <NUM> and the rolling plate <NUM>.

As shown in <FIG>, multiple mini-rollers <NUM> may be used to maintain the curve of the curved portion of the display unit <NUM>. The multiple mini-rollers <NUM> may be arranged at the start and end points of the curved portion of the display unit <NUM> and the middle portion thereof, thereby obtaining the same effect as the roller <NUM> of a larger diameter.

In order to fix the positions of the multiple mini-rollers <NUM>, a roller fixing plate <NUM> to which the multiple mini-rollers <NUM> are to be fastened may be provided at both ends of the mini-rollers <NUM>. The roller fixing plate <NUM> may have a shape corresponding to the curvature of the rolling plate <NUM>, as shown in <FIG>. Since the roller fixing plate <NUM> does not rotate, the roller fixing plate <NUM> may be formed of a material causing low friction in order to allow the rolling plate <NUM> to smoothly slide.

Since the contact surface between the mini-roller <NUM> and the rolling plate <NUM> is small, a high-friction material or a magnet may be used to enhance close contact between the rolling plate <NUM> and the mini-roller <NUM>. The multiple mini-rollers <NUM> may include mini-rollers <NUM> formed of a high-friction material and mini-rollers <NUM> formed of a magnetic material. Since the mini-rollers <NUM> require smaller magnets, it is easier to control magnetic force and friction than with the roller <NUM> of a larger size.

Since the roller <NUM>' shown in <FIG> occupies a smaller space in the radial direction than the roller <NUM> of a larger diameter having a curvature corresponding to the curved portion of the display unit <NUM>, a space where the support link <NUM> is to be disposed may be provided. As shown in <FIG> and <FIG>, the support link <NUM> may be disposed to overlap the roller <NUM>'.

The mobile terminal <NUM> of the present disclosure may allow the size of the screen to be adjusted as needed, thereby satisfying both portability and usability. In addition, the mobile terminal of the present disclosure may reduce the damage to the display unit <NUM> caused by a concentrated stress because stress is not concentrated at a specific point.

A flat state may be maintained regardless of change in the state of the mobile terminal <NUM> by preventing separation or sagging in the mobile terminal <NUM>.

Claim 1:
A mobile terminal (<NUM>) comprising:
a first frame (<NUM>);
a second frame (<NUM>) movable with respect to the first frame (<NUM>) in a first direction such that the mobile terminal is switched from a first state to a second state or in a second direction opposite to the first direction such that the mobile terminal is switched from the second state to the first state;
a slide frame (<NUM>) movable in the first direction or the second direction with respect to the second frame; and
a support link (<NUM>) comprising a first end hinged to the first frame (<NUM>) and a second opposite end hinged to the second frame,
characterised in that
the second frame (<NUM>) comprises:
a front portion (<NUM>) positioned on a front portion of the mobile terminal; and
a rear portion (<NUM>) positioned on a rear portion of the mobile terminal, and the support link (<NUM>) is positioned between the front portion (<NUM>) and the rear portion (<NUM>) and comprises a variable length and a thickness corresponding to a distance between the front portion (<NUM>) and the rear portion (<NUM>).