Patent Description:
A portable electronic device (hereinafter, a mobile terminal) such as a communication terminal, a multimedia device, a portable computer, a game player, and a photographing device is provided with a display to display image information. A mobile terminal may also have a folding structure that can be folded into a smaller size for convenience of portability. In this type of electronic device, two bodies are connected by a folding structure (e.g., a hinge portion).

Since the related art display had a non-foldable structure, a structure in which a display is disposed over foldably connected two bodies could not be implemented. Therefore, a large screen could not actually be applied to an electronic device with a folding structure.

However, as a bendable flexible display has been developed recently, researches to apply a flexible display to a mobile terminal are being conducted, and thus, it is possible to implement a large screen on a device.

Such a flexible display device may realize various sizes of screens by using deformable characteristics of the flexible display. For example, a flexible display device that can be extended to a screen size desired by a user by allowing the flexible display to be drawn out of the device body to extend an area exposed outside may be considered.

However, in the case of such a flexible display device, in order to take advantage of the deformable characteristics of the flexible display, many components should be installed therein, and thus the structure thereof may be complicated. In this case, since a large number of components should be installed in the internal space, utilizing the space is limited, and thus, securing sufficient battery installation space may be difficult. Also, unnecessary load is applied to the flexible display as the flexible display is deformed, and this may result in degrading durability of the device.

In addition, in the flexible display in which two bodies move away from or move closer to each other in one direction to extend or reduce a size of the display, the two bodies moved away from each other may rotate in a direction in which they deviate from each other, thereby degrading the durability or damaging the device.

<CIT> relates to an expandable screen smartphone and expandable screen tablet.

Therefore, it is necessary to propose a mechanism of a flexible display device in which a screen may be exposed to a front surface and a rear surface of a frame, respectively, and consider a method in which two frames (bodies) do not deviate from each other while providing smooth movement of the flexible display.

A first aspect of the present disclosure is to provide a flexible display device having a new mechanism of a rolling type to implement various screens of a flexible display.

A second aspect of the present disclosure is to provide a structure of a flexible display device capable of implementing a smooth movement of a flexible display, being stably supported even in a deformation of the flexible display, and reducing a relative rotation in a mutually opposite direction of two bodies of the device.

The invention is specified by independent claim <NUM>. In the following description, although numerous features may be designated as optional, it is nevertheless acknowledged that all features comprised in the independent claim are not to be read as optional. To achieve the above aspect and other advantages of the present disclosure, there is provided a flexible display device including: a first body and a first frame coupled to the first body; a second body configured to be relatively movable with respect to the first body and a second frame coupled to the second body; a flexible display disposed on a front side of the first body and a rear side of the second body, and a size of a first area of the flexible display exposed to the front side and a size of a second area of the flexible display exposed to the rear side are variable according to relative movement of the second body with respect to the first body; and a rotating bending bar disposed on the first frame and at least a portion inserted into the second frame to couple the first frame and the second frame, and rotated when changing from one of a first state and the second state to the other as the second body slides toward or away from the first body, wherein the first state in which an area of the flexible display exposed to the rear part of the second body is maximized and the second state in which an area of the flexible display exposed to the front part of the first body is maximized; wherein the rotating bending bar comprises: a rotation shaft that is a rotation center of the rotating bending bar; a locking protrusion protruding from the rotation shaft toward the second frame; and a locking hook protruding from the rotation shaft and bent to extend in a direction away from the second frame, and wherein the first frame on which the rotation axis is disposed comprises: a first groove where the rotation shaft is inserted and the inserted rotation shaft is rotated; and a second groove providing a space in which the locking hook rotates.

As another example, respective surfaces of the first frame and the second frame facing each other may be disposed adjacent to each other, and move in a state being parallel to each other when the first frame and the second frame are changed between the first state and the second state.

As another example, the locking protrusion may protrude from the rotation shaft toward the second frame more than a height of the surface of the first frame, and a recessed portion recessed inward from the surface of the second frame corresponding to a protruded height of the locking protrusion may be formed at the second frame.

As another example, the second frame may include a protrusion that is locked to the locking protrusion when the first body and the second body are changed between the first state and the second state, and the rotating bending bar may be rotated as the locking protrusion is locked to the protrusion.

As another example, the protrusion may be disposed at a rear end of the recessed portion.

As another example, an end portion of the locking hook may be rotated from the first frame toward the second frame as the rotating bending bar rotates, and an insertion hole into which the rotated locking hook is inserted may be formed at the second frame.

As another example, at least a part of a body plate of the second frame may be inserted into a lower portion of a bent end portion of the rotated locking hook, as the first body and the second body are changed to the second state.

As another example, the insertion hole may be disposed at an end portion of the protrusion to allow the locking hook to be inserted thereinto when the first body and the second body are changed from the first state to the second state.

As another example, the insertion hole may be provided in plural, and each of the insertion holes may be spaced apart from each other in a direction in which the first body and the second body are moving when changed from the first state to the second state, and the protrusion may be disposed between the spaced insertion holes.

As another example, the rotating bending bar may be disposed in an overlapping area in which the first body and the second body overlap each other in the second state.

The effects of the present disclosure to be obtained by the above-described solutions are as follows.

First, as the first body and the second body are coupled by the rotating bending bar, a deviated rotation when the first body and the second body are changed from the first state to the second state in a direction forming an angle with the first direction in which the second body is moved may be reduced.

That is, the rotating bending bar may couple the first frame and the second frame to each other to prevent the first body and the second body from being relatively moved in the above-described direction. That is, a moment generated around the rotating bending bar may be absorbed by the rotating bending bar. With such a configuration, structural rigidity and stability of the first body and the second body supporting the flexible display are increased.

Second, the protrusion is disposed on an upper end of the locking protrusion of the rotated rotating bending bar so as to prevent reverse rotation of the locking protrusion of the rotated rotating bending bar, thereby preventing a problem in which the rotating bending bar rotated by the protrusion is reversely rotated to obstruct the locking hook from being inserted into the insertion hole.

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 or similar 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 describing the present disclosure, if a detailed explanation for a related known function or construction is considered to unnecessarily divert the scope of the present disclosure, such explanation has been omitted but would be understood by those skilled in the art. The accompanying drawings are used to help easily understand the technical idea of the present disclosure and it should be understood that the idea of the present disclosure is not limited by the accompanying drawings. The idea of the present disclosure should be construed to extend to any alterations, equivalents and substitutes besides the accompanying drawings.

It will be understood that when an element is referred to as being "connected with" another element, the element can be connected with the another 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.

Display devices presented herein may be implemented using a variety of different types of terminals. Examples of such devices include cellular phones, smart phones, user equipment, laptop computers, digital broadcast terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigators, portable computers (PCs), slate PCs, tablet PCs, ultra books, wearable devices (for example, smart watches, smart glasses, head mounted displays (HMDs), and the like.

By way of non-limiting example only, further description will be made with reference to particular types of mobile terminals. However, such teachings apply equally to other types of terminals, such as those types noted above. In addition, these teachings may also be applied to stationary terminals such as digital TV, desktop computers, and the like. Hereinafter, for convenience of description, the mobile terminal will be described as one example of the flexible display device.

The mobile terminal <NUM> may include 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>, a power supply unit <NUM>, etc. It is understood that implementing all of the illustrated components is not a requirement. Greater or fewer components may alternatively be implemented.

In more detail, the wireless communication unit <NUM> may typically include one or more modules which permit communications such as wireless communications between the mobile terminal <NUM> and a wireless communication system, communications between the mobile terminal <NUM> and another mobile terminal, or communications between the mobile terminal <NUM> and an external server. Further, the wireless communication unit <NUM> may typically include one or more modules which connect the mobile terminal <NUM> to one or more networks.

The wireless communication unit <NUM> may include one or more of a broadcast receiver <NUM>, a mobile communication module <NUM>, a wireless Internet module <NUM>, a short-range communication module <NUM>, and a location information module <NUM>.

First, regarding the wireless communication unit <NUM>, the broadcast receiver <NUM> is configured to receive a broadcast signal and/or broadcast associated information from an external broadcast managing server via a broadcast channel. In some embodiments, two or more broadcast receivers may be utilized to facilitate simultaneous reception of two or more broadcast channels, or to support switching among broadcast channels.

The broadcast management server may be a server that generates and transmits a broadcast signal and/or broadcast associated information or a server that receives a previously generated broadcast signal and/or broadcast associated information and transmits the same to a terminal. The broadcast signal may include a TV broadcast signal, a radio broadcast signal, a data broadcast signal, and the like. Also, the broadcast signal may further include a broadcast signal in a form that a TV or radio broadcast signal is combined with a data broadcast signal.

The broadcast signal may be encrypted by at least one of technical standards (or broadcasting methods, e.g., ISO, IEC, DVB, ATSC, etc.) for transmitting and receiving a digital broadcast signal. The broadcast receiving module <NUM> may receive the digital broadcast signal using a method suitable for a technical standard selected from those technical standards.

Examples of the broadcast associated information may include information associated with a broadcast channel, a broadcast program, a broadcast service provider, and the like. The broadcast associated information may be provided via a mobile communication network. In this case, the broadcast associated information may be received by the mobile communication module <NUM>.

The broadcast associated information may be implemented in various formats. For instance, broadcast associated information may include Electronic Program Guide (EPG) of Digital Multimedia Broadcasting (DMB), Electronic Service Guide (ESG) of Digital Video Broadcast-Handheld (DVB-H), and the like. The broadcast signal and/or the broadcast related information received through the broadcast receiving module <NUM> may be stored in the memory <NUM>.

The mobile communication module <NUM> can transmit and/or receive radio 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).

The radio signal may include various types of data depending on a voice call signal, a video call signal, or a text/multimedia message transmission/reception.

The wireless Internet module <NUM> refers to a module for wireless Internet access.

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), High Speed Uplink Packet Access (HSUPA), Long Term Evolution (LTE), LTE-advanced (LTE-A) and the like.

When the wireless Internet access is implemented according to, for example, WiBro, HSDPA, HSUPA, GSM, CDMA, WCDMA, LTE, LTE-A and the like, as part of a mobile communication network, the wireless Internet module <NUM> performs such wireless Internet access.

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. One example of the wireless area networks is a wireless personal area network.

Here, another mobile terminal (which may be configured similarly to mobile terminal <NUM>) may be a wearable device, for example, a smart watch, a smart glass or a head mounted display (HMD), which is able to exchange data with the mobile terminal <NUM> (or otherwise cooperate with the mobile terminal <NUM>). The short-range communication module <NUM> may sense or recognize the wearable device, and permit communication between the wearable device and the mobile terminal <NUM>. In addition, when the sensed wearable device is a device which is authenticated to communicate with the mobile terminal <NUM>, the controller <NUM>, for example, may cause transmission of at least part of data processed in the mobile terminal <NUM> to the wearable device via the short-range communication module <NUM>. Hence, a user of the wearable device may use the data processed in the mobile terminal <NUM> on the wearable device. For example, when a call is received in the mobile terminal <NUM>, the user may answer the call using the wearable device. Also, when a message is received in the mobile terminal <NUM>, the user can check the received message using the wearable device.

The location information module <NUM> is generally configured to detect, calculate, derive or otherwise identify a position (or current position) of the mobile terminal. For example, when the mobile terminal uses a GPS module, a position of the mobile terminal may be acquired using a signal sent from a GPS satellite. The location information module <NUM> is a module used for acquiring the position (or the current position) and may not be limited to a module for directly calculating or acquiring the position of the mobile terminal.

Next, the input unit <NUM> is for inputting image information (or signal), audio information (or signal), data, or information input from a user. For inputting image information, the mobile terminal <NUM> may be provided with a plurality of cameras <NUM>.

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 <NUM> or stored in memory <NUM>. Meanwhile, 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>. Also, the cameras <NUM> may be located in a stereoscopic arrangement to acquire left and right images for implementing a stereoscopic image.

The microphone <NUM> processes an external audio signal into electric audio (sound) data. The processed audio data can be processed in various manners according to a function executed in the mobile terminal <NUM>. The microphone <NUM> may include assorted noise removing algorithms to remove unwanted noise generated in the course of receiving the external audio signal.

The user input unit <NUM> is a component that receives an input of information from a user. Such user input may enable the controller <NUM> to control operation of the mobile terminal <NUM> in correspondence with the received information. The user input unit <NUM> may include one or more of a mechanical input element (for example, a mechanical key, a button located on a front and/or rear surface or a side surface of the mobile terminal <NUM>, a dome switch, a jog wheel, a jog switch, and the like), or a touch-sensitive input element, among others. As one example, the touch-sensitive input element may be a virtual key, a soft key or a visual key, which is displayed on a touch screen through software processing, or a touch key which is located on the mobile terminal at a location that is other than the touch screen.

The sensing unit <NUM> is generally configured to sense one or more of internal information of the mobile terminal, surrounding environment information of the mobile terminal, user information, or the like, and generate a corresponding sensing signal. The controller <NUM> generally cooperates with the sending unit <NUM> to control operations of the mobile terminal <NUM> or execute data processing, a function or an operation associated with an application program installed in the mobile terminal based on the sensing signal. The sensing unit <NUM> may be implemented using any of a variety of sensors, some of which will now be described in more detail.

The proximity sensor <NUM> refers to a sensor to sense presence or absence of an object approaching a surface, or an object existing near a surface, by using an electromagnetic field, infrared rays, or the like without a mechanical contact. The proximity sensor <NUM> may be arranged at an inner area of the mobile terminal covered by the touch screen, or near the touch screen.

The proximity sensor <NUM>, for example, may include any of a transmissive type photoelectric sensor, a direct reflective type photoelectric sensor, a mirror reflective type photoelectric sensor, a high-frequency oscillation proximity sensor, a capacitance type proximity sensor, a magnetic type proximity sensor, an infrared rays proximity sensor, and the like. When the touch screen is implemented as a capacitance type, the proximity sensor <NUM> may sense proximity of a pointer relative to the touch screen by changes of an electromagnetic field, which is responsive to an approach of an object with conductivity. In this case, the touch screen (touch sensor) may also be categorized as a proximity sensor.

The term "proximity touch" will often be referred to herein to denote the scenario in which a pointer is positioned to be proximate to the touch screen without contacting the touch screen. The term "contact touch" will often be referred to herein to denote the scenario in which a pointer makes physical contact with the touch screen. For the position corresponding to the proximity touch of the pointer relative to the touch screen, such position will correspond to a position where the pointer is perpendicular to the touch screen. The proximity sensor <NUM> may sense proximity touch, and proximity touch patterns (for example, distance, direction, speed, time, position, moving status, and the like). In general, controller <NUM> processes data corresponding to proximity touches and proximity touch patterns sensed by the proximity sensor <NUM>, and cause output of visual information on the touch screen. In addition, the controller <NUM> can control the mobile terminal <NUM> to execute different operations or process different data (or information) according to whether a touch with respect to a point on the touch screen is either a proximity touch or a contact touch.

A touch sensor senses a touch (or a touch input) applied to the touch screen (or the display <NUM>) using any of a variety of touch methods. Examples of such touch methods include a resistive type, a capacitive type, an infrared type, and a magnetic field type, among others.

As one example, the touch sensor may be configured to convert changes of pressure applied to a specific part of the display <NUM>, or convert capacitance occurring at a specific part of the display <NUM>, into electric input signals. The touch sensor may also be configured to sense not only a touched position and a touched area, but also touch pressure and/or touch capacitance. A touch object is generally used to apply a touch input to the touch sensor. Examples of typical touch objects include a finger, a touch pen, a stylus pen, a pointer, or the like.

When a touch input is sensed by a touch sensor, corresponding signals may be transmitted to a touch controller. The touch controller may process the received signals, and then transmit corresponding data to the controller <NUM>. Accordingly, the controller <NUM> may sense which area of the display <NUM> has been touched. Here, the touch controller may be a component separate from the controller <NUM>, the controller <NUM>, and combinations thereof.

Meanwhile, the controller <NUM> may execute the same or different controls according to a type of touch object that touches the touch screen or a touch key provided in addition to the touch screen. Whether to execute the same or different control according to the object which provides a touch input may be decided based on a current operating state of the mobile terminal <NUM> or a currently executed application program, for example.

The touch sensor and the proximity sensor may be implemented individually, or in combination, to sense various types of touches. Such touches include a short (or tap) touch, a long touch, a multi-touch, a drag touch, a flick touch, a pinch-in touch, a pinch-out touch, a swipe touch, a hovering touch, and the like.

If desired, an ultrasonic sensor may be implemented to recognize location information relating to a touch object using ultrasonic waves. The controller <NUM>, for example, may calculate a position of a wave generation source based on information sensed by an illumination sensor and a plurality of ultrasonic sensors. Since light is much faster than ultrasonic waves, the time for which the light reaches the optical sensor is much shorter than the time for which the ultrasonic wave reaches the ultrasonic sensor. The position of the wave generation source may be calculated using this fact. For instance, the position of the wave generation source may be calculated using the time difference from the time that the ultrasonic wave reaches the sensor based on the light as a reference signal.

The camera <NUM>, which has been depicted as a component of the input unit <NUM>, includes at least one a camera sensor (CCD, CMOS etc.), a photo sensor (or image sensors), and a laser sensor.

Implementing the camera <NUM> with a laser sensor may allow detection of a touch of a physical object with respect to a 3D stereoscopic image. The photo sensor may be laminated on, or overlapped with, the display device. The photo sensor may be configured to scan movement of the physical object in proximity to the touch screen. In more detail, the photo sensor may include photo diodes and transistors (TRs) at rows and columns to scan content received at the photo sensor using an electrical signal which changes according to the quantity of applied light. Namely, the photo sensor may calculate the coordinates of the physical object according to variation of light to thus obtain location information of the physical object.

The display <NUM> is generally configured to output information processed in the mobile terminal <NUM>. For example, the display <NUM> may display execution screen information of an application program executing at the mobile terminal <NUM> or user interface (UI) and graphic user interface (GUI) information in response to the execution screen information.

Also, the display <NUM> may be implemented as a stereoscopic display for displaying stereoscopic images.

A typical stereoscopic display may employ a stereoscopic display scheme such as a stereoscopic scheme (a glass scheme), an auto-stereoscopic scheme (glassless scheme), a protrusion scheme (holographic scheme), or the like.

The audio output module <NUM> may receive audio data from the wireless communication unit <NUM> or output audio data stored in the memory <NUM> during modes such as a signal reception mode, a call mode, a record mode, a voice recognition mode, a broadcast reception mode, and the like.

A haptic module <NUM> can be configured to generate various tactile effects that a user feels, perceives, or otherwise experiences. The strength, pattern and the like of the vibration generated by the haptic module <NUM> may be controlled by user selection or setting by the controller <NUM>.

When the mobile terminal <NUM> is connected with an external cradle, the interface unit <NUM> can serve as a passage to allow power from the cradle to be supplied to the mobile terminal <NUM> or may serve as a passage to allow various command signals input by the user from the cradle to be transferred to the mobile terminal therethrough. Various command signals or power input from the cradle may operate as signals for recognizing that the mobile terminal is properly mounted on the cradle.

The memory <NUM> can store programs to support operations of the controller <NUM> and store input/output data (for example, phonebook, messages, still images, videos, etc.). The memory <NUM> may store data related to various patterns of vibrations and audio which are output in response to touch inputs on the touch screen.

The memory <NUM> may include one or more types of storage mediums including a flash memory type, a hard disk type, a solid state disk (SSD) type, a silicon disk drive (SDD) type, a multimedia card micro type, a card-type memory (e.g., SD or DX memory, etc.), a Random Access Memory (RAM), a Static Random Access Memory (SRAM), a Read-Only Memory (ROM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), a Programmable Read-Only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, and the like. The mobile terminal <NUM> may also be operated in relation to a network storage device that performs the storage function of the memory <NUM> over a network, such as the Internet.

The controller <NUM> may typically control operations relating to application programs and the general operations of the mobile terminal <NUM>. For example, the controller <NUM> may set or release a lock state for restricting a user from inputting a control command with respect to applications when a status of the mobile terminal meets a preset condition.

The power supply unit <NUM> receives external power or provides internal power and supply the appropriate power required for operating respective elements and components included in the wearable device <NUM> under the control of the controller <NUM>. The power supply unit <NUM> may include a battery, which is typically rechargeable or be detachably coupled to the terminal body for charging.

The power supply unit <NUM> may include a connection port. The connection port may be configured as one example of the interface unit <NUM> to which an external charger for supplying power to recharge the battery is electrically connected.

Various embodiments described herein may be implemented in a computer-readable medium, a machine-readable medium, or similar medium using, for example, software, hardware, or any combination thereof.

The display <NUM> may include at least one of a liquid crystal display (LCD), a thin film transistor-LCD (TFT LCD), an organic light-emitting diode (OLED), a flexible display, a three-dimensional (3D) display and an e-ink display.

The display <NUM> may be implemented using two display devices, according to the configuration type thereof. For instance, a plurality of the displays <NUM> may be arranged on one side, either spaced apart from each other, or these devices may be integrated, or these devices may be arranged on different surfaces.

The display <NUM> may include a touch sensor that senses a touch with respect to the display <NUM> so as to receive a control command in a touch manner. Accordingly, when a touch is applied to the display <NUM>, the touch sensor may sense the touch, and a controller <NUM> may generate a control command corresponding to the touch. Contents input in the touch manner may be characters, numbers, instructions in various modes, or a menu item that can be specified.

The microphone <NUM> may be configured to receive the user's voice, other sounds, and the like. The microphone <NUM> may be provided at a plurality of places, and configured to receive stereo sounds.

The interface unit <NUM> may serve as a path allowing the mobile terminal <NUM> to interface with external devices. For example, the interface unit <NUM> may be at least one of a connection terminal for connecting to another device (for example, an earphone, an external speaker, or the like), a port for near field communication (for example, an Infrared DaAssociation (IrDA) port, a Bluetooth port, a wireless LAN port, and the like), or a power supply terminal for supplying power to the mobile terminal <NUM>. The interface unit <NUM> may be implemented in the form of a socket for accommodating an external card, such as Subscriber Identification Module (SIM), User Identity Module (UIM), or a memory card for information storage.

At least one antenna for wireless communication may be disposed on the terminal body. The antenna may be embedded in the terminal body or formed in the case. For example, an antenna which configures a part of the broadcast receiver <NUM> (see FIG. 1A) may be retractable into the terminal body. Alternatively, an antenna may be formed in a form of film to be attached onto an inner surface of the housing or a case including a conductive material may serve as an antenna.

The terminal body is provided with a power supply unit <NUM> (see FIG. 1A) for supplying power to the mobile terminal <NUM>. The power supply unit <NUM> may include a batter <NUM> which is mounted in the terminal body or detachably coupled to an outside of the terminal body.

The battery <NUM> may receive power via a power cable connected to the interface unit <NUM>. Also, the battery <NUM> may be (re)chargeable in a wireless manner using a wireless charger. The wireless charging may be implemented by magnetic induction or electromagnetic resonance.

An accessory for protecting an appearance or assisting or extending the functions of the mobile terminal <NUM> may further be provided on the mobile terminal <NUM>. As one example of the accessory, a cover or pouch for covering or accommodating at least one surface of the mobile terminal <NUM> may be provided. The cover or pouch may cooperate with the display <NUM> to extend the function of the mobile terminal <NUM>. Another example of the accessory may be a touch pen for assisting or extending a touch input onto a touch screen.

(a) of <FIG> is a perspective view illustrating an exterior appearance of a front surface of the flexible display device in a first state, and (b) of <FIG> is a perspective view illustrating an exterior appearance of the front surface of the flexible display device in a second state. (a) of <FIG> is a perspective view illustrating an appearance of a rear surface of the flexible display device in the first state, and (b) of <FIG> is a perspective view illustrating an appearance of the rear surface of the flexible display device in the second state.

The flexible display device is a device capable of varying in size of a screen due to a deformation of the flexible display, which may be understood as one of the above-described mobile terminals. In the present disclosure, the device will be referred to as a flexible display device.

The flexible display device <NUM> according to the present disclosure is configured to have a shape in which a flexible display <NUM> is exposed to an outside of a first body <NUM> and a second body <NUM>.

Specifically, as illustrated in <FIG> and <FIG>, the flexible display device <NUM> may provide a screen to a user in various ways by exposing the flexible display <NUM> to a front surface and a rear surface of the flexible display device <NUM>.

In addition, the size of the screen exposed to the front surface and to the rear surface of the flexible display device <NUM> may vary according to a mutual movement of the first body <NUM> and the second body <NUM>.

As illustrated in <FIG> and <FIG>, the flexible display device <NUM> may implement the first state in which the first body <NUM> and the second body <NUM> are positioned to be close to each other, thereby decreasing an area of the flexible display <NUM> exposed to the front surface of the flexible display device <NUM>.

In the first state, as illustrated in (a) of <FIG>, the area of the flexible display <NUM> exposed to the rear surface of the flexible display device <NUM> is increased.

In addition, as illustrated in (b) of <FIG> and <FIG>, the flexible display device <NUM> may implement the second state in which the first body <NUM> and the second body <NUM> are positioned to be far from each other, thereby increasing the area of the flexible display <NUM> exposed to the front surface of the flexible display device <NUM>.

In the second state, as illustrated in (b) of <FIG>, the area of the flexible display <NUM> exposed to the front surface of the flexible display device <NUM> increases, and correspondingly, as illustrated in (b) of <FIG>, the area of the flexible display <NUM> exposed to the rear surface of the flexible display device <NUM> decreases.

The flexible display device <NUM> may change between the first state and the second state, according to the mutual movement of the first body <NUM> and the second body <NUM>.

Specifically, the first state is described as follows. The area of the flexible display <NUM> exposed to the front surface may be minimum. The area of the flexible display <NUM> exposed to the rear surface may be maximum. A distance between the first body <NUM> and the second body <NUM> may be minimum.

The second state is described as follows. The area of the flexible display <NUM> exposed to the front surface may be maximum. The area of the flexible display <NUM> exposed to the rear surface may be minimum. The distance between the first body <NUM> and the second body <NUM> may be maximum.

In addition, a state in which the device changes from the first state to the second state, or vice versa, may be referred to as a stroke state. That is, the stroke state may refer to a state that is changed from the first state to the second state or changed from the second state to the first state.

When a direction in which the second body <NUM> is moved away from the first body <NUM> is referred to as a first direction, the area of the flexible display <NUM> exposed to the front surface of the flexible display device <NUM> may be increased along the first direction as the flexible display device <NUM> moves in the first direction.

At this time, by the movement in the first direction of the flexible display device <NUM>, the area of the flexible display <NUM> exposed to the rear surface is reduced along the first direction.

In addition, when the second body <NUM> is moved closer to the first body <NUM> in a second direction, which is an opposite direction to the first direction, the area of the flexible display <NUM> exposed to the front surface of the flexible display device <NUM> may be decreased along the second direction as the flexible display device <NUM> moves in the second direction. In this case, the area of the flexible display <NUM> exposed to the rear surface of the flexible display device <NUM> may be increased along the second direction, as the flexible display device <NUM> moves in the second direction.

The flexible display device <NUM> according to the present disclosure may include the flexible display <NUM> that may be deformed by an external force.

The deformation may be at least one of curving, bending, folding, twisting, and rolling of a display module. A deformable display module may be referred to as 'flexible display'. Here, the flexible display <NUM> may include a typical flexible display, electronic paper (e-paper), and a combination thereof.

The typical flexible display refers to a durable display that is lightweight and does not break easily by being fabricated on a thin, flexible substrate, such as paper, which is bent, curved, folded, twisted or rolled while maintaining characteristics of an existing flat panel display.

In addition, the electronic paper is a display to which general ink characteristics are applied, and is different from the existing flat panel display in view of using reflected light. The electronic paper may change information by using a twist ball or electrophoresis using a capsule.

In the flexible display device <NUM> according to the present disclosure, one side of the flexible display <NUM> is configured to be deformed by an external force (for example, configured to have a finite curvature radius (see a roller <NUM> of <FIG>)), and a position of the deformed one side of the flexible display <NUM> is changed according to the mutual movement of the first body <NUM> and the second body <NUM>.

That is, the flexible display device <NUM> may realize the first state and the second state as a position of the flexible display <NUM> deformed along an outer surface of the roller <NUM> to be described later is changed.

The flexible display <NUM> may output visual information through an exposed screen in the first state and the second state. Such visual information is realized by independently controlling an emission of unit pixels (sub-pixels) arranged in a matrix form. The unit pixel denotes an elementary unit for representing one color.

The flexible display <NUM> may be in a curved state (for example, a state having a predetermined curvature along the outer surface of the roller <NUM>) rather than in a flat state in which one side of the flexible display <NUM> is flat in the first state and the second state, respectively.

When an external force is applied to the flexible display <NUM>, the flexible display <NUM> may be deformed into the flat state (or a less curved state) or a more curved state.

Meanwhile, the flexible display <NUM> may be combined with a touch sensor to implement a flexible touch screen (not shown). When a touch is applied to the flexible touch screen (not shown), the controller <NUM> (see <FIG>) may perform a control corresponding to the touch input. The flexible touch screen may be configured to detect a touch input in the stroke state as well as the first state and the second state.

Meanwhile, the flexible display device <NUM> according to this varied example may be provided with a deformation detecting unit to detect a deformation of the flexible display <NUM>. The deformation detecting unit may be included in the sensing unit <NUM> (see <FIG>).

The deformation detecting unit may be provided on one side of the flexible display <NUM> or on the bodies <NUM> and <NUM> to detect information related to the deformation of the flexible display <NUM>. Here, the information related to the deformation may be a direction in which the flexible display <NUM> is deformed, a deformed degree, a deformed position, a deformed time, and an acceleration at which the deformed flexible display <NUM> is restored. In addition, the information may be various which is detectable as the flexible display <NUM> is curved.

Here, the controller <NUM> (see <FIG>) may change information displayed on the flexible display <NUM> or generate a control signal to control functions of the flexible display device <NUM> based on the information related to the deformation of the flexible display <NUM> detected by the deformation detecting unit.

The state of the flexible display <NUM> is not always changed by an external force. For example, when the flexible display <NUM> may be changed from the first state to the second state by a user or by a command of an application, and may be changed from the second state to the first state in the same manner.

The flexible display device <NUM> according to an embodiment of the present disclosure may include a case (e.g., a frame or a cover) defining an exterior appearance. The case may include the first body <NUM> and the second body <NUM>, and various electronic components may be disposed in the first body <NUM> and the second body <NUM>.

The first body <NUM> and the second body <NUM> may define the exterior appearance of the flexible display <NUM>, and the second body <NUM> may slide along the first body <NUM> to make relative movement and form the first state and the second state, respectively.

The flexible display <NUM> may be coupled to one surface of each of the first and second bodies <NUM> and <NUM> that are connected to each other so as to be movable relative to each other, and configured to deform according to the movement of the first body <NUM> and the second body <NUM>.

The flexible display <NUM> may include a first area 230a, a second area 230b, and a third area 230c.

The first area 230a is coupled to be fixed to the front surface of the first body <NUM>. The third area 230c neighboring in the first direction in the first area 230a may partially cover the front surface of the second body <NUM> and partially cover the rear surface of the second body <NUM>, respectively.

The second area 230b is located between the first area 230a and the third area 230c and is fixed to a supporting plate <NUM> sliding in the first direction with respect to the second body <NUM>.

That is, the flexible display <NUM> may include the first area 230a fixed to the first body <NUM>, the second area 230b fixed to the supporting plate <NUM>, and the third area 230c located between the first area 230a and the second area 230b and disposed on the front surface or the rear surface according to a state of the flexible display device <NUM>.

Here, a curvature of the first area 230a and the second area 230b does not change and maintains a flat state, which is a basic state, but the third area 230c may be curved at another side of the second body <NUM> and bent toward the rear surface.

When the flexible display device <NUM> changes from the first state to the second state, the third area 230c positioned adjacent to the first area 230a becomes wider, and at this time, a position of the third area 230c being deformed depends on a position where the second body <NUM> is sliding.

That is, a portion of the flexible display <NUM> being deformed varies according to the state of the flexible display device <NUM>. Accordingly, an external force is not continuously applied to a specific portion of the flexible display <NUM>. Thus, it is possible to reduce an accumulation of fatigue at any particular portion, and to prevent the flexible display <NUM> from being easily damaged.

The first area 230a of the flexible display <NUM> may be coupled to the front surface of the first body <NUM>. Since the rear surface of the first body <NUM> is always exposed to the outside, a camera, a flash, a proximity sensor, or the like may be disposed on the rear surface.

A side surface (not shown) is provided around the first body <NUM>, and defines an exterior of the flexible display device <NUM> except for an end portion in the first direction in which the second body <NUM> is inserted or drawn out. In addition, the interface unit to connect a power port or an ear jack or the user input unit such as a volume button may be disposed on the side surface. The side surface may serve as an antenna when it includes a metal material.

The rear surface of the second body <NUM> may be configured to support a part of the third area 230c of the flexible display <NUM>. The second body <NUM> is supported by the side surface of the first body <NUM>, and when changed from the first state to the second state, the second body <NUM> may support the rear surface of the extended flexible display <NUM> and support the third area 230c of the flexible display <NUM>.

The first body <NUM> and the second body <NUM> respectively support one area of the flexible display <NUM>, and a plurality of electronic components to operate the flexible display device <NUM> and a battery to form a power source may be mounted in an inner space formed by the first body <NUM> and the second body <NUM>.

Here, as illustrated in <FIG> and <FIG>, the flexible display device <NUM> is configured such that the second body <NUM> is relatively slidable with respect to the first body <NUM>, thereby implementing the first state in which the first body <NUM> and the second body <NUM> are positioned to be closer to each other and are configured to widen an exposed area of the rear surface.

In addition, the flexible display device <NUM> may be changed to the second state in which the first body <NUM> and the second body <NUM> are located far from each other and an exposed area of the front surface is increased. Accordingly, the user can utilize a screen of various size more conveniently by using the respective areas 230a, 230b, and 230c of the flexible display <NUM>, and thus can use the screen in performing various tasks such as an e-book and web surfing.

<FIG> is a cross-sectional view of the flexible display device in the first state, and <FIG> is a cross-sectional view of the flexible display device in the second state.

The flexible display device <NUM> may include the first body <NUM>, the second body <NUM>, the supporting plate <NUM>, the flexible display <NUM>, and a rotating bending bar <NUM>.

The first body <NUM> and the second body <NUM> define the exterior appearance of the flexible display device, and may be changed between the first state and the second stated according to the mutual movement of the first body <NUM> and the second body <NUM>.

The second body <NUM> may move closer to or away from the first body <NUM> while sliding with respect to the first body <NUM>. Accordingly, as illustrated in <FIG>, the first state in which the second body <NUM> faces the first body and is in close contact with the first body may be provided, or as illustrated in <FIG>, the second state in which the first body <NUM> and the second body <NUM> are away from each other may be provided.

In addition, a side surface of the second body <NUM> may be made of an opaque material or a transparent material. In this case, a transparent window is provided on the side surface of the second body <NUM>, so that images or characters output from the flexible display <NUM> may be exposed to the outside.

That is, the flexible display <NUM> may include the first area 230a fixed to the first body <NUM>, the second area 230b fixed to the supporting plate <NUM>, and the third area 230c located between the first area 230a and the second area 230b and disposed on the front surface or the rear surface according to the state of the flexible display device <NUM>.

In this case, the third area 230c may be disposed on the front surface or the rear surface of the flexible display device <NUM> according to the first state and the second state with respect to the mutual movement of the first body <NUM> and the second body <NUM>.

The supporting plate <NUM> is installed on the rear surface of the second body <NUM>, and is a plate-shaped member that slides along the rear surface or the side surface of the second body <NUM>. Since the supporting plate <NUM> is attached to the second area 230b of the flexible display <NUM>, when the second body <NUM> is inserted into or drawn out from the first body <NUM>, the supporting plate <NUM> may be moved relative to the second body <NUM> to correspond to the inserted or drawn out distance of the second body <NUM>.

The flexible display device may further include a driving unit.

The driving unit serves to form a driving force so that the second body <NUM> slides with respect to the first body <NUM>, and may be installed in an inner space formed by the first body <NUM> and the second body <NUM>. The driving unit may be installed and fixed to an inner side the first body <NUM>.

The driving unit allows the second body <NUM> to slide in the first direction with respect to the first body <NUM>, and in this case, allows the supporting plate <NUM> to slide in the first direction with respect to the second body <NUM>.

The driving unit may form a movement in a front-rear direction of the second body <NUM> through a rotational force by a motor (not shown), and may change respective exposed areas on the front surface and a rear surface of the flexible display <NUM> of the flexible display device according to the front-rear direction movement of the second body <NUM>.

As the second body <NUM> slides in the first direction away from the first body <NUM> by the driving unit, the second state may be provided.

The driving unit may include a roller, a connecting rod, a rack, a motor, a gear, and the like, and may allow the second body <NUM> to slide with respect to the first body <NUM> by forming a movement of the rack through the rotational force generated by the motor and moving the roller <NUM> connected to the rack.

For example, in a case of changing from the first state of <FIG> to the second state of <FIG> by the driving unit, when the second body <NUM> moves by a first distance d, the flexible display <NUM> moves by a second distance 2d corresponding to twice the first distance. In this case, in order for an end portion of the flexible display <NUM> to move by the second distance 2d, the supporting plate <NUM> in the second body <NUM> may also move by the distance 2d same as the distance in which the end portion of the flexible display <NUM> is moved.

The driving unit may allow the flexible display device <NUM> to interchange between the first state and the second state in a manner of forming a movement of the second body <NUM>.

In addition, the flexible display device <NUM> may further include a rear surface plate <NUM>. When the first state and the second state are implemented by the movement of the first body <NUM> and the second body <NUM>, the rear surface plate <NUM> coupled to the flexible display <NUM> may also be deformed.

The rear surface plate <NUM> may be coupled to the rear surface of the flexible display <NUM>. The rear surface plate <NUM> supports the flexible display <NUM>, and may be deformed to correspond to a deformed one side of the flexible display <NUM> as the flexible display device <NUM> implements the first and second states.

The rear surface plate <NUM> may be made of thin stainless steel (STS). Since the rear surface plate <NUM> may be deformed together with the flexible display <NUM>, the first state in (a) of <FIG> and <FIG> and the second state in <FIG> and <FIG> may be implemented.

As the flexible display device <NUM> is deformed from the first state to the second state, one side of the flexible display <NUM> may be deformed to a state in which an angle is changed, which may be implemented by a deformation of the rear surface plate <NUM>.

As described above, the flexible display <NUM> may be exposed to the front surface of the first body <NUM> and to the rear surface of the second body <NUM>, respectively, and may change in size of the areas exposed to the front surface of the first body <NUM> and to the rear surface of the second body <NUM> as the first body <NUM> and the second body <NUM> are relatively moved.

The third area 230c of the flexible display <NUM> may be deformed to have a predetermined curvature at one side together with the rear surface plate <NUM>, and one side of the third area 230c may be curved forming a curved surface together with the rear surface plate <NUM>.

In addition, the flexible display <NUM> may be coupled to the rear surface plate <NUM> by an adhesive member (not shown).

The adhesive member (not shown) serves a role to couple the rear surface of the flexible display <NUM> to one surface of the rear surface plate <NUM>, and may be made of a material having a flexible characteristic to prevent a gap from being formed between the rear surface plate <NUM> and the flexible display <NUM> while the rear surface plate <NUM> and the flexible display <NUM> are deformed.

In addition, the adhesive member (not shown) may prevent a stress that may occur between the rear surface plate <NUM> and the flexible display <NUM> to limit the flexible display <NUM> from being damaged by an external force.

The adhesive member (not shown) may be made of a resin (elastomer resin) having an elastic force by using a synthetic epoxy resin or the like. Accordingly, the adhesive member (not shown) couples the flexible display <NUM> and the rear plate with each other in a close contact manner to allow the flexible display to be smoothly deformed together with the rear plate when one side of the flexible display <NUM> is deformed.

The rotating bending bar <NUM> may be disposed in at least one of the first body <NUM> and the second body <NUM>. Specifically, the rotating bending bar <NUM> may be disposed in any one of the first body <NUM> or the second body <NUM>. In addition, the rotating bending bar <NUM> may be disposed on both the first body <NUM> and the second body <NUM>.

As described above, the rotating bending bar <NUM> is rotated while the first body <NUM> and the second body <NUM> are interchanged between the first state and the second state. Accordingly, the rotating bending bar <NUM> may couple the first body <NUM> and the second body <NUM> to each other.

At this time, at least a part of the rotating bending bar <NUM> may be inserted into a body other than a body at which the rotating bending bar <NUM> is disposed, as described above. For example, as at least a part of the rotating bending bar <NUM> is inserted into a body other than a body at which the rotating bending bar <NUM> is disposed, in a state in which the first body <NUM> and the second body <NUM> are disposed farthest, that is, the second state, the relative rotation of the first body <NUM> and the second body <NUM> may be reduced.

In addition, the first body <NUM> and the second body <NUM> may include a first frame <NUM> and a second frame <NUM>, respectively. The first frame <NUM> is coupled to the first body <NUM> and moved together with the first body <NUM>. The second frame <NUM> is coupled to the second body <NUM> and moved together with the second body <NUM>.

Specifically, referring to <FIG>, the rotating bending bar <NUM> may be coupled to the first frame <NUM> which is coupled to the first body <NUM>. And, a locking hook 305c of the rotating bending bar <NUM> to be described later is disposed toward the first frame <NUM>. Here, the rotating bending bar <NUM> may be disposed in an overlapping area (OL, see (b) of <FIG>) in which the first body <NUM> and the second body <NUM> overlap each other in the second state.

In addition, referring to <FIG>, the rotating bending bar <NUM> is rotated in the second state to be coupled to the second frame <NUM> which is coupled to the second body <NUM>. That is, the locking hook 305c of the rotating bending bar <NUM> disposed in the first frame <NUM> is inserted into the second frame <NUM> to couple the second frame <NUM> to the first frame <NUM>. Accordingly, the first body <NUM> and the second body <NUM> may be coupled to the first frame <NUM> and the second frame <NUM>, respectively.

As the first body <NUM> and the second body <NUM> are coupled by the rotating bending bar <NUM>, a deviated rotation when the first body <NUM> and the second body <NUM> are changed from the first state to the second state in a direction forming an angle with the first direction in which the second body <NUM> is moved may be reduced. Specifically, a rotation of the first body <NUM> in the above-described rotation direction R may be reduced.

<FIG> is an exploded perspective view illustrating the first frame, the second frame, and the rotating bending bar. <FIG> is an exploded perspective view of the first frame, the second frame, and the rotating bending bar illustrated in <FIG>, viewed from different directions. (a) of <FIG> is a perspective view illustrating a state in which the first frame, the second frame, and the rotating bending bar illustrated in <FIG> are coupled in the first state. (b) of <FIG> is a perspective view illustrating a state in which the first frame, the second frame, and the rotating bending bar illustrated in <FIG> are coupled in the second state.

The first frame <NUM>, the second frame <NUM>, and the rotating bending bar <NUM> may be coupled one another in a thickness direction of the flexible display device <NUM>. In addition, the second frame <NUM> may be coupled to the first frame <NUM> and moved to change between the first state and the second state.

The first frame <NUM> may be coupled to the first body <NUM> to move together with the first body <NUM>. The first frame <NUM> may configure at least a part of the first body <NUM>. The first frame <NUM> may have a first groove 310a and a second groove 310b into which the rotating bending bar <NUM> to be described later is inserted.

The first frame <NUM> is coupled to the second frame <NUM> to form a guide groove 310c that is to guide the movement of the first frame <NUM> and the second frame <NUM> in the process of interchanging between the first state and the second state.

The second frame <NUM> may be coupled to the first frame <NUM> in a state where most area of the second frame <NUM> is overlapped with the first frame <NUM>. This state may be referred to as the first state. And, the second state may be provided when the second frame moves in a direction in which the area overlapping the first frame <NUM> is decreased.

Referring to <FIG>, a recessed portion 320a and an insertion hole 320b may be formed in the second frame <NUM>. The recessed portion 320a is an area recessed inward from a surface <NUM> of the second frame such that the second frame <NUM> is not caught by a locking protrusion 305b protruding from a surface <NUM> of the first frame, which will be described later. The insertion hole 320b is an opening into which the locking hook 305c of the rotating bending bar <NUM> to be described later is inserted.

A guide protrusion 320c coupled to the guide groove 310c of the first frame <NUM> may be provided at upper and lower ends of the second frame <NUM>. The guide protrusion 320c may be inserted into the guide groove 310c to guide the movement.

Specifically, referring to <FIG> and <FIG>, the guide groove 310c is formed in the first frame <NUM>, and the guide protrusion 320c is formed in the second frame <NUM>. And, referring to (a) and (b) of <FIG>, the guide groove 310c of the first frame <NUM> and the guide protrusion 320c of the second frame <NUM> are coupled to each other to allow the movement between the first state and the second state.

The rotating bending bar <NUM> may include a rotation shaft 305a, the locking protrusion 305b, and the locking hook 305c.

The rotation shaft 305a constitutes a rotation center of the rotating bending bar. The rotation shaft 305a may be disposed in the first groove 310a of the first frame <NUM>. The rotating bending bar <NUM> is rotated by the second frame <NUM> to be described later in a state of being inserted into the first groove 310a.

The locking protrusion 305b protrudes from the rotation shaft 305a in a direction toward the second frame <NUM>. The locking protrusion 305b may protrude higher than the surface <NUM> of the first frame. Accordingly, the rotating bending bar <NUM> is rotated by being pressed by the second frame <NUM>.

The locking hook 305c protrudes from the rotation shaft 305a and is curved and extended in a direction away from the second frame <NUM>. The second groove 310b may be formed in the first frame <NUM> to provide a space in which the locking hook 305c is rotated.

Meanwhile, as illustrated in <FIG>, the locking protrusion 305b and the locking hook 305c of the rotating bending bar <NUM> may be provided in plural. The locking protrusions 305b and the locking hooks 305c may be spaced apart from each other along a lengthwise direction of the rotation shaft 305a. In this way, as the locking protrusions 305b and the locking hooks 305c are provided in plural, the rotating bending bar <NUM> may stably support the first body <NUM> and the second body <NUM> in an up-down direction.

<FIG> is a cross-sectional view illustrating a state in which the first frame, the second frame, and the rotating bending bar are changed from the first state to the second state. <FIG> and <FIG> are conceptual views illustrating a state in which the first frame, the second frame, and the rotating bending bar of <FIG> are changed between the first state and the second state.

(a) of <FIG> is a cross-sectional view illustrating the first frame <NUM>, the second frame <NUM>, and the rotating bending bar <NUM> in the first state. (a) of <FIG> is a conceptual view illustrating a state in which the first frame <NUM>, the second frame <NUM>, and the rotating bending bar <NUM> are changing from the first state to the second state.

(b) of <FIG> is a cross-sectional view and (b) of <FIG> is a conceptual view illustrating a state in which a protrusion <NUM> of the second frame <NUM> is brought into contact with the locking protrusion 305b of the rotating bending bar <NUM> in the stroke state.

(c) of <FIG> is a cross-sectional view and (c) of <FIG> is a conceptual view illustrating a state in which the rotating bending bar <NUM> is rotated by the protrusion <NUM> of the second frame <NUM> in the stroke state.

(d) of <FIG> is a cross-sectional view and (d) of <FIG> is a conceptual view illustrating the first frame <NUM>, the second frame <NUM>, and the rotating bending bar <NUM> in the second state.

The first frame <NUM> and the second frame <NUM> may be changed between the first state and the second state.

Specifically, as illustrated in (a) of <FIG>, the second frame <NUM> may be moved in a direction away from the first frame <NUM> by the above-described driving unit in the first state. Then, the second frame <NUM> may be continuously moved to allow the first frame <NUM> and the second frame <NUM> to be in the second state as illustrated in (d) of <FIG>.

As described above, since the first frame <NUM> and the second frame <NUM> are coupled to the first body <NUM> and the second body <NUM>, respectively, when the first frame <NUM> and the second frame <NUM> form the second state, the first body <NUM> and the second body <NUM> may also form the second state.

A direction in which the relative rotation of the first body <NUM> and the second body <NUM> with respect to each other is reduced by the rotating bending bar <NUM> is a direction forming an angle with a direction in which the first body <NUM> and the second body <NUM> are moved in a process of changing between the first state and the second state.

In detail, a direction in which the first frame <NUM> and the second frame <NUM> are changed between the first state and the second state is a direction in which the first frame <NUM> and the second frame <NUM> are moved left and right in the drawing. Here, a direction in which the first frame <NUM> and the second frame <NUM> are rotated relative to each other is a direction forming an angle with the left and right direction in the drawing.

Referring to (a) to (d) of <FIG> and <FIG>, when a force is applied in a direction F in which an end portion of the first body <NUM> faces the rear surface of the flexible display device <NUM> in the second state, a force to be rotated in the direction R forming an angle with a direction in which the first body and the second body are changed between the first state and the second state is generated.

Here, as illustrated in <FIG> and <FIG>, the rotating bending bar <NUM> couples the first frame <NUM> and the second frame <NUM> to each other to prevent the first body <NUM> and the second body <NUM> from being relatively moved in the above-described direction. That is, a moment generated around the rotating bending bar <NUM> may be absorbed by the rotating bending bar <NUM>.

Meanwhile, surfaces of the first frame <NUM> and the second frame <NUM> respectively facing each other may be disposed adjacent to each other to maintain a parallel state when the first frame <NUM> and the second frame <NUM> are moving between the first state and the second state. Specifically, referring to <FIG> and <FIG>, the surface <NUM> of the first frame and the surface <NUM> of the second frame maintain a parallel state when changing between the first state and the second state.

Here, the locking protrusion 305b of the rotating bending bar <NUM> may protrude more toward the second frame <NUM> than a height of the surface <NUM> of the first frame on the rotation shaft 305a. Specifically, referring to (a) of <FIG>, the locking protrusion 305b protrudes higher than the surface <NUM> of the first frame and is disposed close to the second frame <NUM>.

In addition, the recessed portion 320a recessed inward from the surface of the second frame <NUM> corresponding to a protruded height of the locking protrusion 305b is formed on the second frame <NUM>. As described above, the recessed portion 320a is recessed inward so that the second frame <NUM> is not caught by the protruded locking protrusion 305b when the second frame <NUM> is moved. Accordingly, the locking protrusion 305b is not caught by the second frame <NUM> at an initial stroke state, that is, at a beginning of a transition from the first state to the second state.

The second frame <NUM> includes the protrusion <NUM> engaged with the locking protrusion 305b when the first body <NUM> and the second body <NUM> are changed between the first state and the second state. Specifically, as illustrated in <FIG> and <FIG>, the second body <NUM> may be changed from the first state to the second stated while passing through the stroke state and moving away from the first body <NUM>.

As described above, the locking protrusion 305b protrudes outward from the surface <NUM> of the first frame. In addition, the protrusion <NUM> of the second frame <NUM> protrudes from the surface <NUM> of the second frame so as to be caught by the locking protrusion 305b described above. Here, the protrusion <NUM> may be considered not protruding from the surface <NUM> of the second frame, but relatively protruded due to the recessed portion 320a recessed from the surface <NUM> of the second frame.

The rotating bending bar <NUM> is rotated as the locking protrusion 305b is caught by the protrusion <NUM>. Specifically, referring to <FIG> and <FIG>, the protrusion <NUM> of the second frame <NUM> is caught by the locking protrusion 305b of the rotating bending bar <NUM> to rotate the rotating bending bar <NUM>.

In addition, the protrusion <NUM> of the rotating bending bar <NUM> may be disposed at a rear end of the recessed portion 320a. As the second frame <NUM> is moved, the locking protrusion 305b is not caught by the second frame <NUM> when the locking protrusion 305b passes through an area of the recessed portion 320a of the second frame <NUM>. And, when the second frame <NUM> continues to move to a state closer to the second state, the protrusion <NUM> of the second frame <NUM> disposed at the rear end of the recessed portion 320a presses the locking protrusion 305b of the rotating bending bar <NUM> so that the rotating bending bar <NUM> is caught by the protrusion <NUM>.

When the rotating bending bar <NUM> is rotated, an end portion of the locking hook 305c is rotated from the first frame <NUM> toward the second frame <NUM>. Specifically, as illustrated in <FIG> and <FIG>, when the locking protrusion 305b is caught by the protrusion <NUM> to rotate the rotating bending bar <NUM>, the end portion of the locking hook 305c is rotated from the first frame <NUM> toward the second frame <NUM>.

The second frame <NUM> is formed with the insertion hole 320b into which the locking hook 305c to be rotated can be inserted. Specifically, referring to <FIG> and <FIG>, when the locking protrusion 305b is pressed and rotated by the protrusion <NUM>, the locking hook 305c is rotated toward the second frame <NUM>. Here, the locking hook 305c may be inserted into the insertion hole 320b formed in the second frame <NUM>. That is, the rotating bending bar <NUM> is changed from the stroke state to the second state and is rotated so that at least a part of the rotating bending bar <NUM> is inserted into the second frame <NUM>.

The insertion hole 320b in the second frame <NUM> may be disposed at the rear end of the protrusion <NUM> so that the locking hook 305c may be inserted into the insertion hole 320b while the first body <NUM> and the second body <NUM> move from the first state to the second state. Specifically, as the protrusion <NUM> presses the locking protrusion 305b to rotate the rotating bending bar <NUM>, the locking hook 305c is rotated toward the second frame <NUM>. Here, the insertion hole 320b is disposed at the rear end of the protrusion <NUM> so that the locking hook 305c can be stably inserted into the insertion hole 320b of the second frame <NUM>.

In this case, a length of the insertion hole 320b may correspond to a length from the locking protrusion 305b of the rotating bending bar <NUM> to the locking hook 305c. Specifically, when the length of the insertion hole 320b is short, the locking hook 305c may not be inserted into the insertion hole 320b due to the locking hook 305c being caught by the second frame <NUM> while the rotating bending bar <NUM> is rotated. And, when the length of the insertion hole 320b is too long, a time duration since the locking hook 305c starts rotating until the second frame <NUM> is inserted into a lower portion of the locking hook 305c increases, which may cause the rotation bending bar <NUM> to be rotated in reverse.

Therefore, it is preferable that the length of the insertion hole 320b is provided in a length in which the locking hook 305c is not caught while the rotating bending bar <NUM> is rotated, and a body plate <NUM> of the second frame <NUM> is drawn into the lower portion of the locking hook 305c immediately after the locking hook 305c is completely rotated.

At least a part of the body plate <NUM> of the second frame <NUM> may be drawn into a lower portion of a bent end of the locking hook 305c rotated as the first body <NUM> and the second body <NUM> are in the second state. In other words, as the body plate <NUM> of the second frame <NUM> is inserted into the lower portion of the locking hook 305c, the first body <NUM> and the second body <NUM> may achieve the second state.

Specifically, the body plate <NUM> of the second frame <NUM> is inserted from the end portion of the locking hook 305c to a point in a length before the locking hook 305c is bent.

At least a part of the body plate <NUM> of the second frame <NUM> is inserted into the lower portion of the locking hook 305c, whereby the first frame <NUM>, the second frame <NUM>, and the rotating bending bar <NUM> are coupled to one another. In particular, since a supporting area <NUM> of the second frame <NUM> supports the rotation shaft of the rotating bending bar <NUM>, when a moment acts in a direction same as R illustrated in (d) of <FIG>, the first frame <NUM> and the second frame <NUM> do not rotate by the moment but the rotating bending bar <NUM> may absorb the moment.

And, the first body <NUM> and the second body <NUM> may achieve the second state before the body plate <NUM> of the second frame <NUM> is brought into contact with a bent portion of the locking hook 305c.

When the body plate <NUM> of the second frame <NUM> does not achieve the second state even after the body plate <NUM> is brought into contact with the bent portion of the locking hook 305c, the second frame <NUM> cannot move further. When the body plate <NUM> of the second frame <NUM> is in the second state before being inserted into the lower end of the locking hook 305c, the locking hook 305c and the second frame <NUM> are not coupled to each other. For this reason, the rotating bending bar <NUM> cannot absorb a rotation moment generated between the first frame <NUM> and the second frame <NUM>.

Therefore, achieving the second state before the body plate <NUM> of the second frame <NUM> is brought into contact the bent portion of the locking hook 305c is preferable. That is, in the second state, an end portion of the body plate <NUM> of the second frame <NUM> is preferably disposed at the lower end of the locking hook 305c. Here, the end portion of the body plate <NUM> of the second frame <NUM> disposed at the lower end of the locking hook 305c is a portion of the body plate <NUM> of the second frame <NUM> positioned on a rear surface of the insertion hole 320b.

Meanwhile, the protrusion <NUM> may be disposed on an upper end of the locking protrusion 305b of the rotated rotating bending bar <NUM> so that the locking protrusion 305b of the rotated rotating bending bar <NUM> is not rotated in reverse. Specifically, as illustrated in (d) of <FIG>, the protrusion <NUM> may be disposed on the upper end of the locking protrusion 305b so that the rotating bending bar <NUM> which has already been rotated does not rotate in reverse. As a result, a problem in which the rotating bending bar <NUM> rotated by the protrusion <NUM> is reversely rotated to obstruct the locking hook 305c from being inserted into the insertion hole 320b may be prevented.

The flexible display device <NUM> according to an embodiment of the present disclosure may reduce a deviated rotation of the first body <NUM> and the second body <NUM> as the rotating bending bar <NUM> is rotated to couple the first frame <NUM> and the second frame <NUM> in the process in which the first frame <NUM> and the second frame <NUM> is changed from the first state to the second state and to couple the first body <NUM> and the second body <NUM> that are respectively coupled to the first frame <NUM> and the second frame <NUM>.

Meanwhile, referring to <FIG> and <FIG>, the insertion hole 320b may be provided in plural. Each of the insertion holes 320b may be spaced apart from each other in a direction when the first body <NUM> and the second body <NUM> are changed from the first state to the second state. In addition, the protrusion <NUM> may be disposed between the spaced insertion holes 320b.

Referring to (b) and (c) of <FIG>, the insertion hole may include the insertion hole 320b and a sub insertion hole 320b'. The sub insertion hole 320b' may provide a space in which the locking protrusion 305b is not caught by the second frame <NUM> when the rotating bending bar <NUM> rotates. However, when a depth of the recessed portion 320a is adjusted, the sub insertion hole 320b' may not be provided.

(a) to (d) of <FIG> describe a movement in which the first frame <NUM>, the second frame <NUM>, and the rotating bending bar <NUM> in the second state are changed to the first state.

Specifically, (a) of <FIG> illustrates the second state, (b) and (c) of <FIG> illustrate the stroke state, and (d) of <FIG> illustrates the first state.

In the second state, the second frame <NUM> may be moved in a direction closer to the first frame <NUM> by the driving unit ((a) of <FIG>). And, as the second frame <NUM> moves closer to the first frame <NUM>, the protrusion <NUM> of the second frame <NUM> presses the upper end of the locking hook 305c of the rotating bending bar <NUM> ((b) of <FIG>). Accordingly, the locking hook 305c is rotated to rotate the rotating bending bar <NUM> ((c) of <FIG>). Subsequently, the second frame <NUM> is moved closer to the first frame <NUM>.

Since the recessed portion 320a of the second frame <NUM> is recessed from the surface <NUM> of the second frame, the locking protrusion 305b of the rotating bending bar <NUM>, which has been returned to its original state, is not pressed by the second frame <NUM> ((d) of <FIG>). As such, when the second frame <NUM> is close to the first frame <NUM>, the first frame <NUM> and the second frame <NUM> may be in the first state again.

Claim 1:
A flexible display device (<NUM>) comprising:
a first body (<NUM>) and a first frame (<NUM>) coupled to the first body (<NUM>);
a second body (<NUM>) configured to be relatively movable with respect to the first body (<NUM>) and a second frame (<NUM>) coupled to the second body (<NUM>);
a flexible display (<NUM>) disposed on a front side of the first body (<NUM>) and a rear side of the second body (<NUM>), and a size of a first area of the flexible display (230a) exposed to the front side and a size of a second area of the flexible display (230b) exposed to the rear side are variable according to relative movement of the second body (<NUM>) with respect to the first body (<NUM>); and
a rotating bending bar (<NUM>) disposed on the first frame (<NUM>) and at least a portion inserted into the second frame (<NUM>) to couple the first frame (<NUM>) and the second frame (<NUM>), and rotated when changing from one of a first state and the second state to the other as the second body (<NUM>) slides toward or away from the first body (<NUM>), wherein the first state in which an area of the flexible display exposed to the rear part of the second body (<NUM>) is maximized and the second state in which an area of the flexible display exposed to the front part of the first body (<NUM>) is maximized;
wherein the rotating bending bar (<NUM>) comprises:
a rotation shaft (305a) that is a rotation center of the rotating bending bar (<NUM>);
a locking protrusion (305b) protruding from the rotation shaft (305a) toward the second frame (<NUM>); and
a locking hook (305c) protruding from the rotation shaft (305a) and bent to extend in a direction away from the second frame (<NUM>), and
wherein the first frame (<NUM>) on which the rotation axis is disposed comprises:
a first groove (310a) where the rotation shaft (305a) is inserted and the inserted rotation shaft (305a) is rotated; and
a second groove (310b) providing a space in which the locking hook (305c) rotates.