Patent Description:
The present disclosure relates to a mobile terminal, and more particularly, to a mobile terminal that has a flexible display and is capable of extending a size of a screen while the display is scrolled and slid at the same time.

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> relates to a mobile terminal, control system, and control method.

<CIT> relates to an electronic device including movable flexible display.

One purpose of the present disclosure is to provide a mobile terminal that may improve durability of a flexible display unit by not restricting a point where the flexible display unit is bent to a specific position.

Another purpose of the present disclosure is to provide a mobile terminal including a support structure of a flexible display unit that may stably support the flexible display unit when the flexible display unit is extended.

Another purpose of the present disclosure is to prevent a flexible display unit from being damaged by an external impact on a side where the flexible display unit is bent.

To achieve these objects and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, a mobile terminal may include a first frame, a second frame configured to slidably move from the first frame in a first direction or a second direction, the second direction being opposite to the first direction, a slide frame configured to move with respect to the second frame in the first direction or the second direction, a flexible display including a first region coupled to the first frame, a second region coupled to the slide frame, and a third region disposed between the first region and the second region, the third region being bent in a manner of surrounding the second frame, and a rolling plate attached to a rear surface of the flexible display, wherein the second frame may include a side portion positioned at an end thereof facing in a third direction perpendicular to the first direction, and a slide rail formed on the side portion, wherein the rolling plate may include a plurality of support bars extending in the third direction perpendicular to the first direction and arranged side by side in the first direction, and a slide hook protruding from an end of each of the support bars and inserted into the slide rail to move along the slide rail.

The slide hook may have a cylindrical shape.

The mobile terminal may further include a ring-shaped slide roller, the slide roller being inserted into the slide hook.

The mobile terminal may further include a fastening groove formed in a ring shape on an outer circumferential surface of the slide hook, and a fastening protrusion protruding from an inner surface of the slide roller and inserted into the fastening groove.

The mobile terminal further includes an expanded side portion positioned the end of each of the support bars and may be expanded more than a cross section of the support bars, wherein the expanded side portion may include a first expanded side portion extending from to a position spaced apart from the flexible display and provided with the slide hook.

A width of the first expanded side portion in the first direction may be narrowed as the first expanded side portion extends away from the flexible display.

The expanded side portion may further include a second expanded side portion forming a step with respect to the first expanded side portion, wherein the second expanded side portion may be disposed to overlap the first expanded side portion of a neighboring support bar among the support bars.

The side portion of the second frame may include an opening positioned on a front side, wherein a width of the opening may correspond to a size of the second expanded side portion.

An end portion of the expanded side portion facing the flexible display may include a curved surface.

The mobile terminal may further include a roller coupled to the second frame to be rotatable about a rotation axis extending in the third direction perpendicular to the first direction, wherein the third region may be bent in a manner of surrounding the roller, wherein each of the support bars may include a curved surface corresponding to a curvature of the roller.

The slide rail may include a first horizontal portion positioned adjacent to a rear of the second frame, a second horizontal portion positioned in front of the second frame and arranged parallel to the first horizontal portion, and a curved portion connecting ends of the first horizontal portion and the second horizontal portion facing in the first direction.

The side portion of the second frame may include an opening positioned on a front side of the first horizontal portion, wherein, when the second frame is moved in the first direction to switch from a first state to a second state, an end of the rolling plate facing in the third direction may be exposed to an outside through the opening.

The mobile terminal may further include a rolling ball inserted into the side portion of the second frame, wherein, when the second frame is moved in the first direction or the second direction, the rolling ball may rotate in contact with the first frame.

The rolling ball may contain a metal material. The mobile terminal may further include a magnet provided in an insertion portion of the second frame to apply magnetic force to the rolling ball, the rolling ball being inserted into the second frame.

The rolling plate may further include a rolling sheet having one surface coupled to the flexible display and an opposite surface coupled to the support bars.

The rolling sheet may include a superelastic metal sheet.

The rolling sheet may include a kerf pattern provided with a plurality of grooves extending in the third direction and arranged in the first direction.

The grooves may be positioned between the support bars.

The mobile terminal may further include an adhesive tape positioned between the rolling sheet and the support bars and between the rolling sheet and the display.

The mobile terminal may further include a flexible connector configured to connect the support bars. 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 caused by a concentrated stress on the display unit because the stress is not concentrated at a specific point.

In addition, the display unit may be maintained in a flat state by preventing the display unit from being separated during movement of the second frame.

Further, as a structure to guide the second frame and the slide frame to move in parallel is provided, distortion may be prevented.

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

The present disclosure will become more fully understood from the detailed description given herein below and the accompanying drawings, which are given by illustration only, and thus are not limitative of the present disclosure, and wherein:.

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 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> 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 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>. The rear portion1015 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 rear portion <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.

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>, and 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>, so that 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. <FIG> shows the first state and <FIG> shows the second state. 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 D1 or pushes the same in the second direction D2 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 cause 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 should have a large diameter to provide large force. Two motors <NUM> may be used as shown in <FIG> to provide driving force of a predetermined magnitude or more in the limited space of the mobile terminal <NUM> without increasing the thickness.

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 display unit <NUM> and 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 include materials such as SUS or ferrosilicon (FeSi).

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 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 that is formed by being gradually narrowed from the surface portion of the rolling sheet <NUM>.

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 illustrating an issue raised in an extendable mobile terminal <NUM>. The figure shows the end of the second frame <NUM> in the third direction when the second frame <NUM> is extended as switching from the first state to the second state occurs. Since the display unit <NUM> contains a flexible material, the display unit <NUM> may be bent at a position corresponding to the roller <NUM>. However, when the display unit <NUM> is positioned on the front of the mobile terminal <NUM> in the second state, it should be maintained in a flat state. Since the rolling plate <NUM> is not fixed to the second frame <NUM>, the display unit <NUM> may sag downward as shown in <FIG> or rise upward as shown in <FIG>.

The sagging issue of the display unit <NUM> (in <FIG>) may be addressed when the support bars <NUM> of the rolling plate <NUM> described above support the rear surface of the third region 151c of the display unit <NUM> and the front portion of the second frame <NUM> supports the support bars <NUM>. However, in order to address an issue that the display unit <NUM> moved to the front is not arranged flat but is separated from the second frame <NUM> as shown in <FIG>, the rolling plate <NUM> and the second frame <NUM> may further include a slide structure <NUM>, <NUM>. The slide structures <NUM> and <NUM> may fasten the rolling plate <NUM> (the display unit <NUM>) so as not to be separated from the second frame <NUM> in the thickness direction of the mobile terminal <NUM> while allowing the movement thereof only in the first direction or the second direction.

<FIG> are views showing the slide structures <NUM> and <NUM> provided on the rolling plate <NUM> and the second frame <NUM>. <FIG> is a cross-sectional view taken along lines C-C and D-D in <FIG>, <FIG> is a cross-sectional view taken along lines E-E and F-F in <FIG>, and <FIG> is a view showing an expanded side portion <NUM> and a guide hook <NUM> of the mobile terminal <NUM> in accordance with an embodiment.

As shown in <FIG>, the rolling plate <NUM> may include a slide hook <NUM> protruding toward the second side portion <NUM> positioned on the side of the second frame <NUM> facing in the third direction. As shown in <FIG>, the second side portion <NUM> of the second frame <NUM> may include a slide rail <NUM> into which the slide hook <NUM> is movably inserted. <FIG> shows the slide rail <NUM> formed on the second side portion <NUM> of the second frame <NUM>. The slide rail <NUM> may include a pair of horizontal portions 1027a and 1027b arranged side by side in a thickness direction and a curved portion 1027c connecting ends of the horizontal portions 1027a and 1027b facing in the first direction. The pair of horizontal portions 1027a and 1027b and the curved portion 1027c may form a U shape, and the slide hook <NUM> may move along the slide rail <NUM>.

In the first state, the slide hook <NUM> may be positioned in the horizontal portion 1027a, 1027b positioned on the rear side, as shown in <FIG>. In the second state, the slide hook <NUM> may be moved to the horizontal portion 1027a, 1027b positioned on the front side, as shown in <FIG>. When moved from the rear horizontal portion 1027a, 1027b to the front horizontal portion 1027a, 1027b, the slide hook <NUM> may pass through the curved portion 1027c. When the slide hooks <NUM> pass through the curved portion 1027c, the rolling plate <NUM> may be bent and the space between the slide hooks <NUM> may be narrowed.

The slide rail <NUM> along which the slide hook <NUM> moves may guide the movement of the slide hook <NUM> and the movement of the slide frame <NUM> simultaneously. Since the slide frame <NUM> is also disposed adjacent to the support bars, a slide hook <NUM> protruding from the slide frame <NUM> may be further provided.

<FIG> shows the second frame <NUM> in the first state in which the first frame <NUM> and the second frame <NUM> overlap each other, and <FIG> shows the second frame <NUM> moved from the first frame <NUM> in the first direction in the second state. As shown in <FIG>, the support bars <NUM> and the slide hooks <NUM> are positioned on the rear in the first state. In the second state, as shown in <FIG>, the support bars <NUM> and the slide hooks <NUM> are positioned on the front. The distance from the front face of the display unit <NUM> to the front horizontal portions 1027a and 1027b may be equal to the distance from the rear face of the display unit <NUM> to the rear horizontal portions 1027a and 1027b.

When large friction occurs during movement of the slide hooks <NUM> along the slide rail <NUM>, a large load may be applied to the driving unit <NUM>, thereby generating frictional noise or affecting the durability of the product. A self-lubricating member having high abrasion resistance and low friction resistance, such as polyoxymethylene (POM), may be used to facilitate the movement of the slide hooks <NUM> on the slide rail <NUM>. By forming the slide hooks <NUM> in a cylindrical shape, the area thereof in contact with the slide rail <NUM> may be minimized.

As illustrated in <FIG>, a slide roller <NUM> fitted onto the slide hook <NUM> may be further provided. The slide roller <NUM> may be fitted onto the cylindrical slide hook <NUM> to rotate about an axis extending in a direction in which the slide hook <NUM> protrudes. The slide roller <NUM> may rotate when the slide hook <NUM> moves along the slide rail <NUM>, thereby reducing friction generated between the slide roller <NUM> and the slide rail <NUM>.

A bearing structure may help to reduce the friction, but it may increase the overall size. For this reason, a simple ring-shaped slide roller <NUM> may be used. A fastening groove 1043a and a fastening protrusion 1044a may be further provided to prevent the slide roller <NUM> from being separated from the slide hook <NUM>. When the fastening protrusion 1044a is inserted into the fastening groove 1043a, the fastening groove 1043a formed on the outer circumferential surface of the slide hook <NUM> in a ring shape and the ring-shaped fastening protrusion 1044a protruding from the inner surface of the slide roller <NUM> are fastened to each other.

The second side portion <NUM> of the second frame <NUM> is disposed overlapping the first side portion <NUM> of the first frame <NUM> in the first state, and is exposed to the outside in the second state. Since the second side portion <NUM> is positioned inside the first side portion <NUM> of the first frame <NUM> in the first state, it may be difficult to connect the interface unit <NUM>, the user input unit <NUM>, the audio output unit <NUM>, the antenna, and the like, which are positioned on the first side portion <NUM>, to the printed circuit board <NUM>, which is positioned inside.

The second side portion <NUM> may include an opening 1023a formed by omitting at least a part of the second side portion <NUM> to connect the components positioned on the first side portion <NUM> to the printed circuit board <NUM> positioned inside the first frame <NUM>. Through the opening 1023a, a connector may be arranged between the components positioned on the first side portion <NUM> and the printed circuit board. The opening 1023a may have a shape elongated in the first direction to prevent interference between the connector and the second side portion <NUM> of the second frame <NUM> even when the second frame <NUM> is moved.

However, in order to prevent the inside of the mobile terminal <NUM> from being exposed through the opening 1023a in the second state, an expanded side portion <NUM> may be formed at an end of the support bar <NUM> to cover the opening 1023a in the second state. The expanded side portion <NUM> may have a larger area than the cross section of the support bar <NUM> at the end of the support bar <NUM>. The slide hook <NUM> may be formed on a first expanded side portion 1042a extending in a direction away from the display unit <NUM>. When the slide hook <NUM> is disposed parallel to the support bar <NUM>, the second side portion <NUM> of the second frame <NUM> should be extended adjacent to the display unit <NUM>, which may make it difficult to form the opening 1023a. Accordingly, the slide hooks <NUM> may be formed at positions spaced apart from the display unit <NUM> by a predetermined distance. The first expanded side portion 1042a may be formed in a fan shape to have a width that is reduced as the first expanded side portion 1042a extends in a direction away from the display unit <NUM>. <FIG> is a view showing an embodiment of the rolling plate <NUM> of the mobile terminal <NUM>. Since the rolling plates at positions on the curved portion 1027c of the slide rail <NUM> spaced apart from the display portion <NUM> are disposed adjacent to each other, the first expanded side portion 1042a may be formed in a fan shape to prevent the rolling plates from overlapping each other.

The expanded side portion <NUM> may also extend in the left-right direction, and may thus cover a space between neighboring support bars <NUM>. The expanded side portion <NUM> may further include a second expanded side portion 1042b forming a step with respect to the first expanded side portion 1042a as shown in <FIG>. The second extension side portion 1042b may be disposed to overlap the first expanded side portion 1042a adjacent thereto to cover the space between the support bars <NUM>. The second expanded side portion 1042b may have a size corresponding to the thickness-wise size of the opening <NUM> a formed in the second side portion <NUM> of the second frame <NUM>. The second expanded side portion 1042b may be formed to be shorter than the first expanded side portion 1042a on the side spaced apart from the display unit <NUM>. The second expanded side portion 1042b may be formed to be shorter than the first expanded side portion 1042a to prevent the second expanded side portions 1042b from overlapping each other when the rolling plates pass through the curved portion 1027c of the slide rail <NUM>. The second expanded side portion 1042b may be formed to have a size corresponding to the size of the opening 1023a to cover the space between the first expanded side portions 1042a to prevent the inside of the second frame <NUM> from being exposed to the outside.

As shown in <FIG>, the second expanded side portion 1042b may have any shape as long as the shape ensures that the second expanded side portions 1042b do not interfere with each other, and allows the second expanded side portion 1042b to cover the space between the first expanded side portions 1042a and to cover the opening 1023a of the second side portion <NUM> of the frame <NUM>. It may have a rectangular shape as shown in <FIG> or a semicircular shape as shown in <FIG>.

<FIG> is a view illustrating distortion and shaking of the first frame <NUM> and the second frame <NUM> of the mobile terminal <NUM>. As shown in <FIG>, the first frame <NUM> and the second frame <NUM> may be distorted in the longitudinal direction (vertical direction) of the mobile terminal <NUM> and during slide movement thereof. Such distortion may wrinkle the display unit <NUM> or cause damage to the slide structure.

As shown in <FIG>, the first frame <NUM> and the second frame <NUM> need to be spaced apart from each other by a predetermined distance for slide movement. If they closely contact each other, friction may increase, thereby obstructing slide movement. Accordingly, the frames may be spaced apart from each other by a gap of about <NUM>. However, this gap may cause distortion as shown in <FIG>. Accordingly, a member that may allow horizontal movement of the second frame <NUM> without shaking while maintaining the gap is needed.

<FIG> is a view showing a rolling ball <NUM> employed to address the issue illustrated in <FIG>. As shown in <FIG>, the rolling ball <NUM> is inserted into a concave insertion portion formed in the second side portion <NUM> of the second frame <NUM>. The rolling ball <NUM> may be in contact with the first frame <NUM> on one side and may rotate within the insertion portion of the second side portion when the second frame <NUM> moves in the first direction. When the rolling ball <NUM> is rotatably inserted, the rolling ball <NUM> may be displaced in the assembly process because the second frame <NUM> has no structure to fix the rolling ball <NUM>. To address this issue, as shown in <FIG>, a magnet <NUM>' may be placed inside the insertion portion, and the rolling ball <NUM> may be made of a magnetic material. Thereby, the rolling ball <NUM> may be prevented from being displaced from the insertion portion when the first frame <NUM> and the second frame <NUM> are connected.

The rolling ball <NUM> may protrude as far as the gap between the first frame <NUM> and the second frame <NUM> to contact the first frame <NUM>. Thereby, the second frame <NUM> may be prevented from being distorted due to the gap. In addition, since the second frame <NUM> is spaced apart from the first frame <NUM> by a predetermined distance rather than directly contacting the first frame <NUM> and the rolling ball <NUM> rotates during movement of the second frame <NUM>, friction generated when the mobile terminal switches between the states may be minimized.

As described above, 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.

Further, as a structure to guide the second frame and the slide frame <NUM> to move in parallel is provided, distortion may be prevented.

Claim 1:
A mobile terminal comprising:
a first frame (<NUM>);
a second frame (<NUM>) configured to move with respect to the first frame (<NUM>) in a first direction and a second direction opposite to the first direction, wherein the second frame (<NUM>) comprises a side portion (<NUM>) positioned at an end thereof facing in a third direction perpendicular to the first direction and a slide rail (<NUM>) formed on the side portion (<NUM>);
a flexible display (<NUM>) comprising a fixed portion(151a) coupled to the first frame (<NUM>), and a variable portion (151c) bent to curve around the second frame (<NUM>);
a rolling plate (<NUM>) attached to a rear side of the variable portion (151c) of the flexible display (<NUM>) and comprising support bars (<NUM>) extending in the third direction, wherein the support bars (<NUM>) are arranged in the first direction;
a first expanded side portion (1042a) extended from the end of each of the support bars (<NUM>) to a position spaced apart from the flexible display (<NUM>); and
a slide hook (<NUM>) protruding from an end of the first expanded side portion (1042a) and inserted into the slide rail (<NUM>) to move along the slide rail (<NUM>).