Patent Description:
A portable electronic device (hereinafter, a mobile terminal) such as a communication terminal, a multimedia device, a portable computer, a game machine and a capturing device is provided with a display for displaying video information. The mobile terminal may have a folding structure to be folded into a smaller size, for convenience of portability. In such an electronic device, two bodies are connected to each other by a folding structure (e.g., a hinge unit).

Since the conventional display has no folding structure, it was impossible to implement a structure to arrange a display on two bodies connected to each other in a foldable manner. Therefore, it was impossible to apply a large screen to an electronic device of a folding structure.

However, as a flexible display which can be bent is being developed recently, research to apply such a flexible display to a mobile terminal is actively ongoing. In this case, since the flexible display is arranged on two bodies through a folding structure, a large screen may be implemented.

In a flexible display device, a flexible display is transformable into a folding state and an unfolding state by using a hinge unit. However, when the folding state is converted into the unfolding state or vice versa, an unnecessary load may be applied to the flexible display, or a folding in a reverse direction may be performed to cause inconvenience to a user.

Therefore, there is provided a mechanism of a flexible display device, capable of having a display long in a vertical direction in a folding state for utilization as a smart phone, and having a screen ratio of about <NUM>:<NUM> in an unfolding state. Here, considered is a method for providing a smooth movement of a flexible display unit for implementation of various states.

To illustrate the prior art, <CIT> discloses the preamble of claim <NUM>.

Therefore, an aspect of the detailed description is to provide a flexible display device which can perform folding and unfolding, and which can provide a display unit of various sizes to a user, for utilization as a mobile phone, a note and a tablet.

Another aspect of the detailed description is to provide a flexible display device which can perform a smooth movement by folding and unfolding of a flexible display unit, which can smoothly support the flexible display unit in spite of a state change of the flexible display unit, and which can prevent an unnecessary load from being applied to the flexible display unit.

To achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, a flexible display device has a structure that one body has one side to which another body is rotatably connected, and a flexible display unit is foldable.

More specifically, a flexible display device includes: a first body having a plurality of parts connected to each other so as to be relatively moveable; a second body connected to the first body so as to be relatively rotatable; a flexible display unit formed to be folded and unfolded, and arranged on a front surface of the first body and the second body; and a hinge unit installed at one side of the first body, configured to connect the first body and the second body to each other for relative rotation, and formed of a plurality of hinge segments, wherein in a folding state of the flexible display unit, the second body may be arranged to cover a rear surface of the first body as an interval between the hinge segments is changed.

In an embodiment of the present disclosure, in an unfolding state of the flexible display unit, the first body and the second body may be arranged in parallel in a state that the hinge unit is interposed therebetween.

In an embodiment of the present disclosure, the hinge segments may be sequentially arranged in one direction, and the hinge segments may be arranged to enclose a side surface of the first body in a folding state of the flexible display unit.

In the present invention, the flexible display device further includes a rear plate coupled to a rear surface of the flexible display unit, configured to support the flexible display unit, and formed to be transformed together with the flexible display unit.

The rear plate includes mounting portions extended in one direction, and recessed to couple the rear surface of the flexible display and a bending supporting portion extended towards the outside from both sides of the mounting portions.

In an embodiment of the present disclosure, a bonding member may be formed between an upper surface of the rear plate and a bottom surface of the flexible display unit.

In the present invention, the bending supporting portion is formed to be bent by being concaved downward, and a metallic supporting member is coupled to a bottom surface of the bending supporting portion, in correspondence to a shape of the bottom surface.

In an embodiment of the present disclosure, a molding member having a concavo-convex shape may be coupled to an upper surface of the bending supporting portion.

In an embodiment of the present disclosure, the transformation portion may have a plurality of extension bars arranged in parallel and spaced from each other by predetermined intervals, so as to be transformed in correspondence to folding and unfolding of the flexible display unit.

In an embodiment of the present disclosure, the plurality of parts of the first body may include: a first part; and a second part arranged to be slidable by a predetermined distance along the first part.

In an embodiment of the present disclosure, the plurality of parts of the first body may further include: a plurality of links installed between the first part and the second part, and connected to each other so as to be relatively rotatable; and an elastic member formed to be extended or contracted in correspondence to a movement of the plurality of links.

In an embodiment of the present disclosure, the flexible display unit may be fixedly-coupled to the first part and the second body.

In an embodiment of the present disclosure, a flexible display device includes: a first body having a plurality of parts connected to each other so as to be relatively moveable; a second body connected to the first body so as to be relatively rotatable; a flexible display unit formed to be folded and unfolded, and arranged on a front surface of the first body and the second body; a hinge unit installed at one side of the first body, configured to connect the first body and the second body to each other for relative rotation, and formed of a plurality of hinge segments; and a rear plate coupled to a rear surface of the flexible display unit, configured to support the flexible display unit, and formed to be transformed together with the flexible display unit, wherein the hinge segments may be sequentially arranged in one direction, and the hinge segments may be arranged to enclose a side surface of the first body in a folding state of the flexible display unit, and wherein in a folding state of the flexible display unit, the second body may be arranged to cover a rear surface of the first body as an interval between the hinge segments is changed.

Effects of the present disclosure obtained by the aforementioned solution means are as follows.

Firstly, the flexible display unit having two screen sizes of a folding state and an unfolding state may be implemented through a foldable structure.

Secondly, through an interworking structure of the bodies, a connection operation of a folding state and an unfolding state may be implemented in a compact space.

Thirdly, through a configuration of the rear plate, the flexible display unit can be smoothly supported. Also, since a length compensation can be performed when the flexible display unit is bent, damage of the flexible display unit may be prevented at the time of a folding operation and an unfolding operation.

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 gist 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 a flexible display device.

The mobile terminal <NUM> may be 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 (or control unit) <NUM>, and a power supply unit <NUM>. 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 receiving module <NUM>, a mobile communication module <NUM>, a wireless Internet module <NUM>, a short-range communication module <NUM>, and a location information module <NUM>.

The input unit <NUM> may include a camera <NUM> or an image input unit for obtaining images or video, a microphone <NUM>, which is one type of audio input device for inputting an audio signal, and a user input unit <NUM> (for example, a touch key, a mechanical key, and the like) for allowing a user to input information. Data (for example, audio, video, image, and the like) may be obtained by the input unit <NUM> and may be analyzed and processed according to user commands.

The sensing unit <NUM> may typically be 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 include at least one of a proximity sensor <NUM>, 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). The mobile terminal disclosed herein may be configured to utilize information obtained from one or more sensors of the sensing unit <NUM>, and combinations thereof.

The output unit <NUM> may typically be configured to output various types of information, such as audio, video, tactile output, and the like. The output unit <NUM> may be shown having at least one of a display unit <NUM>, an audio output module <NUM>, a haptic module <NUM>, and an optical output module <NUM>. The display unit <NUM> may have an inter-layered structure or an integrated structure with a touch sensor in order to implement a touch screen. The touch screen may function as the user input unit <NUM> which provides an input interface between the mobile terminal <NUM> and the user and simultaneously provide an output interface between the mobile terminal <NUM> and a user.

The interface unit <NUM> serves as an interface with various types of external devices that are coupled to the mobile terminal <NUM>.

Application programs may be stored in the memory <NUM>, installed in the mobile terminal <NUM>, and executed by the controller <NUM> to perform an operation (or function) for the mobile terminal <NUM>.

The controller <NUM> typically functions to control an 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 by the aforementioned various components, or activating application programs stored in the memory <NUM>.

Also, the controller <NUM> may control at least some of the components illustrated in <FIG>, to execute an application program that have been stored in the memory <NUM>. In addition, the controller <NUM> may control at least two of those components included in the mobile terminal <NUM> to activate the application program.

The power supply unit <NUM> may be configured to receive external power or provide internal power in order to supply appropriate power required for operating elements and components included in the mobile terminal <NUM>.

At least part of the components may cooperatively operate to implement an operation, a control or a control method of a mobile terminal according to various embodiments disclosed herein. Also, the operation, the control or the control method of the mobile terminal may be implemented on the mobile terminal by an activation of at least one application program stored in the memory <NUM>.

Hereinafter, description will be given in more detail of the aforementioned components with reference to FIG. 1A, prior to describing various embodiments implemented through the mobile terminal <NUM>.

First, regarding the wireless communication unit <NUM>, the broadcast receiving module <NUM> is typically configured to receive a broadcast signal and/or broadcast associated information from an external broadcast managing entity via a broadcast channel. In some embodiments, two or more broadcast receiving modules 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 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).

The wireless 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.

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.

Examples of such inputs include audio, image, video, data, and user input. Image and video input is often obtained using one or more 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 unit <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 being executed in the mobile terminal <NUM>. If desired, 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> 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 located 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> can 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 unit <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 unit <NUM>, or convert capacitance occurring at a specific part of the display unit <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 unit <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>, typically 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.

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

A typical stereoscopic display unit may employ a stereoscopic display scheme such as a stereoscopic scheme (a glass scheme), an auto-stereoscopic scheme (glassless scheme), a projection 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 module <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 unit <NUM> may be implemented using two display devices, according to the configuration type thereof. For instance, a plurality of the display units <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 unit <NUM> may include a touch sensor that senses a touch with respect to the display unit <NUM> so as to receive a control command in a touch manner. Accordingly, when a touch is applied to the display unit <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 receiving module <NUM> (see <FIG>) 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>) 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 unit <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.

<FIG> is a perspective view of a flexible display device, which shows an outer folding state. And <FIG> is a perspective view of the flexible display device, which shows an unfolding state.

The flexible display device <NUM> may be understood as a type of the aforementioned mobile terminal, and the device may be referred to as a flexible display device for convenience in this specification.

The flexible display device <NUM> according to the present disclosure may be provided with a flexible display unit <NUM> which is formed to be transformable by an external force. And a rear plate <NUM> is coupled to a rear surface of the flexible display unit <NUM>. Accordingly, the flexible display unit <NUM> may be transformable smoothly.

Here, the transformation may mean at least one of curve, bending, folding, twist and rolling of a display module. Such a transformable display module may be referred to as 'flexible display'. Here, the flexible display unit <NUM> may include a general flexible display, e-paper and a combination thereof.

A general flexible display indicates a display having characteristics of the conventional flat display, manufactured on a thin and flexible substrate which can be curved, bent, folded, twisted and rolled like paper, and thus having a light and strong characteristic.

Further, electronic paper is a display technology using a general ink characteristic, which may be different from the conventional flat display in that reflected light is used. The electronic paper may change information by using twist balls, or by using an electrophoresis using capsules.

The flexible display device <NUM> according to the present disclosure may have a state that the flexible display unit <NUM> is transformed by an external force (e.g., a folded state having a finite curvature radius, hereinafter, will be referred to as first state, refer to <FIG>), and a state that the flexible display unit <NUM> is not transformed (e.g., a state having an infinite curvature radius, hereinafter, will be referred to as second state, refer to <FIG>). In the second state, a display region of the flexible display unit <NUM> is planar.

As shown, information displayed in the first state may include visual information outputted on a curved surface. Such visual information is implemented as light-emitting of sub pixels arranged in the form of matrices is controlled independently. The sub pixels mean a minimum unit to implement a single color.

The flexible display unit <NUM> may have a curved state, not a flat state in the first state (e.g., a curved state up and down or right and left, a folded state). In this case, if an external force is applied to the flexible display unit <NUM>, the flexible display unit <NUM> may be transformed to a flat state (or a less curved state) or a more curved state.

The flexible display unit <NUM> may implement a flexible touch screen (not shown) by combining with a touch sensor. When a touch input is applied to the flexible touch screen (not shown), the controller <NUM> (refer to <FIG>) may perform a control corresponding to the touch input. The flexible touch screen may be configured to sense a touch input not only in the first state, but also in the second state.

The flexible display device <NUM> according to a modification of the present disclosure may be provided with a transformation sensing means for sensing a transformation of the flexible display unit <NUM>. The transformation sensing means may be included in the sensing unit <NUM> (refer to <FIG>).

The transformation sensing means may be provided at the flexible display unit <NUM> or bodies <NUM>, <NUM>, thereby sensing information related to a transformation of the flexible display unit <NUM>. The information related to a transformation may be a transformation direction, a transformation degree, a transformation position, a transformation time of the flexible display unit <NUM>, and an acceleration to restore the transformed flexible display unit <NUM>. Also, the information may be various information which can be sensed due to bending of the flexible display unit <NUM>.

The controller <NUM> (refer to <FIG>) may change information displayed on the flexible display unit <NUM>, or may generate a control signal for controlling a function of the flexible display device <NUM>, based on the information related to a transformation of the flexible display unit <NUM> sensed by the transformation sensing means.

A state transformation of the flexible display unit <NUM> is not limited to a transformation by an external force. For instance, when the flexible display unit <NUM> is in the first state, the first state may be changed into the second state by a command of a user or an application.

The flexible display device <NUM> according to an embodiment of the present disclosure may be provided with a case (for instance, a frame, a cover, etc.) for forming appearance. The case may include the first body <NUM> and the second body <NUM>, and various types of electronic components may be arranged in the first body <NUM> and the second body <NUM>.

The flexible display device <NUM> may be provided on one surface of each of the first and second bodies <NUM>, <NUM> rotatably connected to each other, and may be transformed by a movement of the first and second bodies <NUM>, <NUM>.

As shown in <FIG>, the flexible display unit <NUM> may be formed to be folded together with a movement of the second body <NUM> in the first state. The flexible display unit <NUM> may be folded to cover an upper surface of the first body <NUM> together with the second body <NUM> in an outwardly-exposed state, and a rear surface of the first body <NUM> may be overlapped with the second body <NUM>.

More specifically, the first body <NUM> of the flexible display device <NUM> supports one region of the flexible display unit <NUM>, and the second body <NUM> of the flexible display device <NUM> supports another region (the remaining region) of the flexible display unit <NUM>. Here, a plurality of electronic components for driving the flexible display device <NUM> may be mounted to at least one of the first and second bodies <NUM>, <NUM>.

That is, the first and second bodies <NUM>, <NUM> may perform a relative rotation in a connected state to each other, with a predetermined angle. And the flexible display unit <NUM> may be in a folded state (first state) to overlap at least one region thereof, by being bent.

As shown in <FIG>, the flexible display device <NUM> may have an unfolding state (second state) that the flexible display unit <NUM> is unfolded. In this case, the first and second bodies <NUM>, <NUM> are arranged on the same plane in parallel, and the flexible display unit <NUM> is in an unfolded state by the first and second bodies <NUM>, <NUM>. Accordingly, a user can perform various tasks such as an electronic book and a web surfing more conveniently, by utilizing a large screen.

<FIG> are conceptual views showing implementable states of the flexible display device <NUM>.

The flexible display device <NUM> may implement the first state that rear surfaces of the first and second bodies <NUM>, <NUM> face each other, by folding. In this case, the flexible display unit <NUM> is arranged outside the bodies so that an outer surface of the flexible display unit <NUM> is exposed to the outside. The mobile terminal according to this embodiment may implement a flexible display device of an outer folding structure. Under the outer folding structure, the flexible display unit <NUM> is exposed to the outside at the time of a folding operation, and covers an outer surface of the first body <NUM> together with the second body <NUM>.

The flexible display device <NUM> may have an unfolding state (second state) that the flexible display unit <NUM> is unfolded. In this case, the first and second bodies <NUM>, <NUM> may be arranged on the same plane in parallel.

While the first state is changed into the second state, an angle formed by one region and another region of the flexible display unit <NUM> may be variable. The flexible display unit <NUM> may be gradually folded by interworking with the angle variation. This can allow the first state to be converted into the second state.

In the first state, the first and second bodies <NUM>, <NUM> are overlapped with each other, and a space between one region and another region of the flexible display unit <NUM> may be bent with a curved surface. In this case, the curved surface may be implemented by a hinge unit <NUM>.

As shown in <FIG>, since the second body <NUM> is folded to the flexible display unit <NUM> with respect to the first body <NUM>, the hinge unit <NUM> is configured to enclose one side surface of the first body <NUM> at the time of a folding operation.

Here, one side surface of the first body <NUM> may have a thickness greater than that of the second body <NUM>, and the first body <NUM> encloses one side surface of the second body <NUM> together with the flexible display unit <NUM>. As a result, an outer folding may be implemented.

The rear plate <NUM> may be coupled to the rear surface of the flexible display unit <NUM>. The rear plate <NUM> can implement the first state shown in <FIG> and the second state shown in <FIG> by being transformed together with the flexible display unit <NUM>.

The flexible display device <NUM> may implement an outer folding structure as the rear plate <NUM> is transformed together with the flexible display unit <NUM>. Under the outer folding structure, the flexible display unit <NUM> is in an outward-exposed state at the time of a folding operation, and may have a structure to cover an outer surface of the first body <NUM> together with the second body <NUM>.

As shown in <FIG>, the flexible display device <NUM> may implement the first state that rear surfaces of the first and second bodies <NUM>, <NUM> face each other, as one side of the flexible display unit <NUM> is folded together with the rear plate <NUM>. Here, the outer side surface of the flexible display unit <NUM> maintains an outwardly-exposed state, and is arranged outside each of the first and second bodies <NUM>, <NUM>.

As shown in <FIG>, the flexible display device <NUM> may have an unfolding state (second state) that the flexible display unit <NUM> is unfolded. In the second state, the first and second bodies <NUM>, <NUM> may be arranged on the same plane in parallel.

While the first state of the flexible display device <NUM> is changed into the second state, an angle formed by one region and another region of the flexible display unit <NUM> may be variable. This can be implemented by a transformation of the rear plate <NUM>.

The rear plate <NUM> may be folded by a transformation of a transformation portion 235a. And a region of the flexible display unit <NUM>, corresponding to the transformation portion 235a is gradually folded as an angle of the transformation portion 235a of the rear plate <NUM> is changed. This can allow the first state to be converted into the second state.

As shown in <FIG>, the flexible display device <NUM> may implement the first state that the flexible display unit <NUM> is folded, and the second state that the flexible display unit <NUM> is unfolded. Accordingly, a user may utilize a mobile terminal which is used at ordinary times, as a note or a tablet more conveniently.

That is, the flexible display device <NUM> according to the present disclosure can implement the flexible display unit <NUM> having two screen sizes of a folding state and an unfolding state, and can provide a user with two modes of a phone and a note or a tablet. Further, through an interworking structure of the bodies <NUM>, <NUM>, a connection operation of a folding state and an unfolding state may be implemented in a compact space.

<FIG> is a planar view showing an inner form of the flexible display device <NUM> having the flexible display unit <NUM> removed therefrom, and <FIG> is a disassembled perspective view of the flexible display device <NUM>.

The flexible display device <NUM> may include the first body <NUM>, the second body <NUM>, the flexible display unit <NUM> and the hinge unit <NUM>. Under such a structure, the flexible display unit <NUM> may implement a first state (folding) and a second state (unfolding).

Also, the flexible display unit <NUM> can implement the first state (folding) and the second state (unfolding) by movement of the first body <NUM> and the second body <NUM>, by being coupled to the rear plate <NUM>.

The rear plate <NUM> may be coupled to a rear surface of the flexible display unit <NUM>. The rear plate <NUM> serves to support the flexible display unit <NUM>, and can be transformed together with the flexible display unit <NUM> as the flexible display device <NUM> implements folding (the first state) and unfolding (the second state).

A detailed structure of the rear plate <NUM> will be explained later.

The first body <NUM> may be provided with a plurality of parts connected to each other so as to be relatively moveable with respect to each other. The first body <NUM> may include a first part <NUM> and a second part <NUM>.

The first part <NUM> is a part which can be held by a user's hand, and may form appearance of a rear surface of the first body <NUM>.

The first part <NUM> may be formed to have a '<IMG>' shape. And a fixing portion <NUM> may be formed at one side of the first part <NUM>. The fixing portion <NUM> is formed to fix one side of links 214b to be explained later.

In the first part <NUM>, may be installed the links 214b formed to be extended and contracted according to whether the flexible display unit <NUM> is extended or not.

The second part <NUM> is formed to have a '<IMG>' shape, and may be installed to face the first part <NUM>. The hinge unit <NUM> may be coupled to one side of the second part <NUM>, and the second part <NUM> may be rotatably coupled to the second body <NUM>.

The second part <NUM> may be installed so as to be slidable between itself and the first part <NUM>. Both sides of the second part <NUM>, extended towards the first part <NUM>, may be slidable by being supported at both sides of the first part <NUM>.

The second part <NUM> performs a sliding operation by a predetermined distance between itself and the first part <NUM>, thereby compensating for a length change due to folding or unfolding of the flexible display unit <NUM>.

The plurality of parts of the first body <NUM> may further include a plurality of links 214b installed between the first part <NUM> and the second part <NUM> and rotatably connected to each other, and an elastic member <NUM> formed to be extended or contracted in correspondence to a movement of the plurality of links 214b.

A relative movement of the first part <NUM> and the second part <NUM> may be implemented as the first part <NUM> and the second part <NUM> are arranged in a state that the plurality of links 214b rotatably connected to each other and the elastic member <NUM> are interposed therebetween.

The second body <NUM> has a structure to be connected to the first body <NUM> so as to be relatively rotatable through the hinge unit <NUM>, thereby implementing a folding state of the flexible display device <NUM>.

The flexible display unit <NUM> coupled to the rear plate <NUM> is coupled to one surface of the second body <NUM>, and a user may grasp (hold) the second body <NUM> for folding or unfolding.

When the flexible display unit <NUM> is in a folding state (the first state), the second body <NUM> may be arranged to cover the rear surface of the first body <NUM>. In this case, the flexible display unit <NUM> is exposed to the outside.

The hinge unit <NUM> for connecting the first body <NUM> and the second body <NUM> to each other so as to be relatively rotatable is arranged at one side of the first body <NUM>. As the hinge unit <NUM> is operated, the second body <NUM> may be folded to be overlapped with the first body <NUM>.

The flexible display unit <NUM> is coupled to one surface of the second body <NUM>, and a user may grasp (hold) the second body <NUM> for folding or unfolding.

The hinge unit <NUM> is provided with a plurality of hinge segments <NUM> sequentially arranged in one direction, and each of the hinge segments <NUM> may be arranged to enclose the side surface of the first body <NUM> in a folding state of the flexible display unit <NUM>.

The flexible display unit <NUM> is formed to have a flexible characteristic for folding. The flexible display unit <NUM> is arranged on the front surface of the first body <NUM> and the second body <NUM>, and can be transformed in correspondence to folding and unfolding of the first body <NUM> and the second body <NUM>.

As shown in <FIG>, a main PCB <NUM> for processing a signal for driving of the flexible display device <NUM>, a battery <NUM> for power supply, and a driver IC (not shown) for operating the flexible display unit <NUM> may be positioned so as to be overlapped with the second body.

A hardware component <NUM> having various types of sensors and a camera module may be positioned so as to be overlapped with a first fixing housing 215a, and a sub PCB <NUM> may be positioned so as to be overlapped with the second part <NUM>.

<FIG> is a perspective view showing a first state of the flexible display device <NUM>. <FIG> are perspective views showing a front surface and a rear surface of hinge segments <NUM> of the hinge unit <NUM>. And <FIG> are conceptual views showing various embodiments of the hinge unit <NUM> for folding of the flexible display unit <NUM> of the flexible display device <NUM>.

The hinge unit <NUM> may serve to connect the first and second bodies <NUM>, <NUM> to each other so as to be relatively rotatable with respect to each other, and may be arranged between the first and second bodies <NUM>, <NUM>. The first and second bodies <NUM>, <NUM> may be connected to each other by the hinge unit <NUM> so as to be relatively rotatable with respect to each other.

Since one side surface of the first body <NUM> has a thickness greater than that of the second body <NUM>, the hinge unit <NUM> encloses the one side surface of the first body <NUM> at the time of folding.

The hinge unit <NUM> may be provided with a plurality of hinge segments <NUM> sequentially arranged in one direction.

The hinge segments <NUM> may be arranged to enclose one side surface of the first body <NUM> in a folding state of the flexible display unit <NUM>.

The hinge segment <NUM> may be arranged between the first and second bodies <NUM>, <NUM>.

As shown in <FIG>, in the first state, the hinge segments <NUM> may be arranged along a curved surface of the first body <NUM>, and each hinge segment <NUM> may be rotatably connected to its neighboring hinge segment <NUM> for folding.

The hinge segment <NUM> may be formed so that an interval of at least part of its neighboring hinge segment <NUM> is changed by folding and unfolding of the flexible display unit <NUM>.

As shown in <FIG>, first magnets 242a having a magnetism may be installed at one side of each hinge segment <NUM>, so that the hinge segments <NUM> arranged to be adjacent to each other can have a rotation displacement. The first magnets 242a may be installed at a plurality of positions of each hinge segment <NUM>.

As shown in <FIG>, second magnets 242b having a different magnetism from the first magnets 242a may be installed at another side of each hinge segment <NUM>.

As shown in <FIG>, when the flexible display device <NUM> is in an unfolding state that the first body <NUM> and the second body <NUM> are arranged in parallel, the first magnets 242a and the second magnets 242b of each hinge segment 241are closely-attached to each other between the hinge segments <NUM> arranged to be adjacent to each other. Accordingly, the unfolding state may be maintained.

When the flexible display device <NUM> has a bent shape, each of the hinge segments <NUM> may be arranged to face the rear surface of the flexible display unit <NUM>.

Here, a folding state and an unfolding state can be maintained and a counter-bending of the hinge unit <NUM> can be prevented, through an elastic force of a torsion spring <NUM> installed at a central region of each of the hinge segments <NUM> arranged to be adjacent to each other.

That is, each of the hinge segments <NUM> guides folding and unfolding of the second body <NUM>, and a bent sectional shape thereof guides to have a predetermined curvature.

<FIG> is a perspective view showing the rear plate <NUM>. <FIG> is a partially enlarged view showing a metallic supporting member coupled to the rear plate <NUM>, and <FIG> is a sectional view showing the flexible display unit <NUM> coupled to the rear plate <NUM>.

The rear plate <NUM> is coupled to the rear surface of the flexible display unit <NUM>, and may be formed to be transformable together with the flexible display unit <NUM>.

The rear plate <NUM> may be formed to be folded or unfolded for the first and second states of the flexible display device <NUM>.

The rear plate <NUM> may be formed of a stainless (STS) thin film.

The rear plate <NUM> may be provided with mounting portions 233a for coupling the rear surface of the flexible display unit <NUM>, and a transformation portion 235a which is transformable in correspondence to a movement of the flexible display unit <NUM>. Also, the rear plate <NUM> may be provided with a bending supporting portion <NUM> extended towards the outside from both sides of the mounting portions.

The mounting portion 233a for forming a bottom surface of the rear plate <NUM> may be formed in the shape of a thin plate which is extended in one direction, and may be concaved with a predetermined depth so as to mount the rear surface of the flexible display unit <NUM>.

The rear plate <NUM> may be provided with a bending supporting portion <NUM> extended towards the outside from both sides of the mounting portions 233a. The bending supporting portion <NUM> may be formed to be bent by being concaved downward, and may have a bendable structure in one direction. For instance, the bending supporting portion <NUM> may be bent in a U-shape.

As shown in <FIG>, a metallic supporting member <NUM> may be coupled to a bottom surface of the bending supporting portion <NUM>.

The metallic supporting member <NUM> may be formed to have a shape corresponding to the bottom surface of the bending supporting portion <NUM>. And the metallic supporting member <NUM> may be extended in one direction along the bottom surface of the bending supporting portion <NUM> of the rear plate <NUM>.

The metallic supporting member <NUM> may be formed to maintain a parallel state when the flexible display unit <NUM> is unfolded, and to maintain a bent state when the flexible display unit <NUM> is folded. The metallic supporting member <NUM> may be formed of titanium (Ti) specially processed to maintain a bent state by transformation.

The transformation portion 235a serves to transform the flexible display unit <NUM>. The transformation portion 235a may be formed to be transformable for implementation of folding or unfolding of the flexible display unit <NUM>.

The transformation portion 235a can be transformed so that the rear plate <NUM> is folded.

As shown in the enlarged part of <FIG>, the transformation portion 235a may have a structure that a plurality of extension bars 235c which connect both sides of the bending supporting portion <NUM> are arranged in parallel. When the flexible display unit <NUM> is folded, the plurality of extension bars 235c can be bent by forming a relative movement with the neighboring extension bars 235c, in correspondence to the movement of the flexible display unit <NUM>. Accordingly, the rear plate <NUM> can be folded, and thus the flexible display unit <NUM> coupled to the rear plate <NUM> can be folded.

Alternatively, the transformation portion 235a can be formed by cutting a selected region of the rear plate <NUM> by predetermined intervals. In this case, may be obtained the same effect as the plurality of extension bars 235c which connect the bending supporting portions <NUM> positioned at both sides of the mounting portions 233a.

The transformation portion 235a may be formed at a position corresponding to the hinge unit <NUM>, and can be bent for implementation of the first state that the flexible display unit <NUM> is folded.

As shown in <FIG>, the flexible display unit <NUM> can be coupled to the mounting portions 233a by a bonding member <NUM>.

The bonding member <NUM> may be installed between the flexible display unit <NUM> and the mounting portions 233a of the rear plate <NUM>.

The bonding member <NUM> serves to firmly couple a lower surface of the flexible display unit <NUM> to a bottom surface of the rear plate <NUM>. The bonding member <NUM> may be formed of a flexible material so that a gap of the flexible display unit <NUM> is prevented, the gap occurring when there is a space between the rear plate <NUM> and the flexible display unit <NUM>, as the rear plate <NUM> and the flexible display unit <NUM> are transformed.

Further, the bonding member <NUM> may serve to restrict damage of the flexible display unit <NUM> by an external force, by preventing a stress occurring between the rear plate <NUM> and the flexible display unit <NUM>.

For instance, the bonding member <NUM> may be formed of elastomer resin having an elastic force, by using synthetic epoxy resin, etc. Accordingly, the bonding member <NUM> serves to firmly couple the flexible display unit <NUM> and the rear plate <NUM> to each other, and is smoothly transformed together with the rear plate <NUM> in correspondence to the flexible display unit <NUM> even if the flexible display unit <NUM> is transformed by folding and unfolding.

The mounting portions 233a may have a structure to be concaved in a U-shape. The mounting portion 233a may include a horizontal portion <NUM> having a flat shape so as to be coupled to the rear surface of the flexible display unit <NUM>, and a vertical portion <NUM> upward extended from both ends of the horizontal portion <NUM> so as to cross the horizontal portion <NUM>.

The flexible display unit <NUM> may be coupled onto the horizontal portion <NUM> of the mounting portion 233a of the rear plate <NUM> by the bonding member <NUM>.

Here, the flexible display unit <NUM> may be formed to have the same height as the vertical portion <NUM>. In this case, since the flexible display unit <NUM> is formed to have the same height as the bending supporting portion <NUM>, appearance exposed to the outside may be enhanced more.

<FIG> is an enlarged sectional view showing an arrangement structure of the rear plate <NUM> and the flexible display unit <NUM>, in a second state where the flexible display unit <NUM> has been unfolded. And <FIG> is a conceptual view showing the second part <NUM> in the second state.

<FIG> is an enlarged sectional view showing an arrangement structure of the rear plate <NUM> and the flexible display unit <NUM>, in a first state where the flexible display device <NUM> has been folded. And <FIG> is a conceptual view showing the second part <NUM> in the first state.

As aforementioned, the first and second bodies <NUM>, <NUM> of the flexible display device <NUM> may be connected to each other by the hinge unit <NUM> so as to be relatively rotatable with respect to each other.

Here, the hinge unit <NUM> serves to connect the first and second bodies <NUM>, <NUM> to each other so as to be relatively rotatable with respect to each other, and may be arranged between the first and second bodies <NUM>, <NUM>. The flexible display unit <NUM> is arranged on one surface of the first and second bodies <NUM>, <NUM>, and can be folded and unfolded by the relative rotation.

The hinge unit <NUM> may include a plurality of hinge segments <NUM> sequentially arranged in one direction, and each of the hinge segments <NUM> may be arranged to enclose the side surface of the first body <NUM> in the first state that the flexible display unit <NUM> is folded.

Here, the transformation portion 235a may be formed at a position corresponding to the hinge unit <NUM>, and can be bent for implementation of the first state that the flexible display unit <NUM> is folded.

Further, the transformation portion 235a may be provided with a plurality of extension bars 235c. The transformation portion 235a can be transformed into a shape corresponding to folding of the hinge unit <NUM>, in order to implement the first state that the first and second bodies <NUM>, <NUM> are overlapped with each other.

If the hinge unit <NUM> is folded for implementation of the first state of the flexible display device <NUM>, the transformation portion 235a of the rear plate <NUM> may be transformed in correspondence to folding of the hinge unit <NUM>.

More specifically, if the hinge unit <NUM> is folded, each extension bar 235c of the transformation portion 235a, arranged to be overlapped with the hinge unit <NUM> up and down may have its position changed.

That is, if the hinge unit <NUM> is folded, a distance between the neighboring extension bars 235c of the transformation portion 235a is changed. Accordingly, the transformation portion 235a can be bent in correspondence to folding of the hinge unit <NUM>.

When the hinge segments <NUM> of the hinge unit <NUM> are converted to a folding state from an unfolding state, a distance of one end may become far from a rotation center of the hinge segments <NUM>, and the flexible display unit <NUM> may be arranged to cover the one end.

That is, as shown in <FIG>, at the time of a folding operation, one upper end of the flexible display unit becomes far from the rotation center of the hinge segments <NUM>, whereas another lower end of the flexible display unit becomes close to the rotation center. In this case, the first and second bodies <NUM>, <NUM> may perform a relative sliding in order to compensate for the distance change.

That is, when the flexible display unit <NUM> is folded, it is required to compensate for a length change due to a transformation of the hinge unit <NUM>. Accordingly, the elastic member <NUM> of the first body <NUM> may be extended or contracted to compensate for the length change due to a transformation of the hinge unit <NUM>.

As shown in <FIG>, if the flexible display unit <NUM> is folded together with the rear plate <NUM>, the elastic member <NUM> installed at the first body <NUM> is extended or contracted to thus partially compensate for the length change due to a transformation of the hinge unit <NUM>.

Here, a region of the rear plate <NUM> is fixed to the second body <NUM>. Accordingly, as the elastic member <NUM> installed for sliding of the second part <NUM> of the first body <NUM>, and the links 214b installed at both sides of the elastic member <NUM> are extended and contracted, the length change due to a transformation of the hinge unit <NUM> can be compensated.

Further, since the elastic member <NUM> is installed at the second part <NUM>, sliding of the second part <NUM> may be implemented.

The second part <NUM> has a structure to be slidable towards the first part <NUM>. One side of the second part <NUM> may be connected to one of the hinge segments <NUM>.

One end of the elastic member <NUM> may be connected to the second part <NUM>, and another end thereof may be connected to the fixing portion <NUM> of the first part <NUM>. The elastic member <NUM> may be configured to provide an elastic force to the second part <NUM> by being compressed or extended, and to compensate for a distance due to bending of the hinge unit <NUM>. Here, the elastic member <NUM> may provide an elastic force to the second part <NUM> in a direction which becomes far from the hinge unit <NUM>.

As shown in <FIG>, the elastic member <NUM> may provide a maximum elastic force in a lengthwise direction of the mobile terminal, if the hinge unit <NUM> and the second body <NUM> are spaced away from each other to the maximum.

As shown in <FIG>, if the hinge unit <NUM> and the second body <NUM> are close to each other to the maximum by folding of the second body <NUM>, the elastic member <NUM> is in a closely-attached state to thus provide no elastic force.

<FIG> is a perspective view showing a rear plate <NUM> according to another embodiment of the present disclosure. <FIG> is a partially enlarged view showing a molding member <NUM> coupled to the rear plate <NUM>. And <FIG> is a sectional view showing a lamination structure of a flexible display unit <NUM> coupled to the rear plate <NUM>.

The rear plate <NUM> is coupled to a rear surface of the flexible display unit <NUM>, and may be transformed together with the flexible display unit <NUM>.

The rear plate <NUM> may be formed to be folded or unfolded for implementation of first and second states of a flexible display device <NUM>.

The rear plate <NUM> may be formed of stainless (STS) thin film. The rear plate <NUM> may be provided with mounting portions 333a, 333a' for coupling the rear surface of the flexible display unit <NUM>, transformation portion 335a which is transformable in correspondence to a movement of the flexible display unit <NUM>, and a bending supporting portion <NUM> extended towards the outside from both sides of the mounting portions.

The transformation portion 335a of the rear plate <NUM> can be transformed through a position and a structure thereof, for implementation of folding or unfolding of the flexible display unit <NUM>. And a bonding member <NUM> is installed between the flexible display unit <NUM> and the mounting portions 333a, 333a' of the rear plate <NUM>. These have been aforementioned, and thus detailed descriptions thereof will be omitted.

However, the flexible display device <NUM> according to this embodiment may be provided with the bending supporting portion <NUM> extended towards the outside from both sides of the mounting portions 333a, 333a' of the rear plate <NUM>. Here, an outer side surface of the bending supporting portion <NUM> may have a flat shape.

A molding member <NUM> may be coupled to an upper surface of the bending supporting portion <NUM>. A bottom surface of the molding member <NUM> may have a flat shape to correspond to the upper surface of the bending supporting portion <NUM>, and an upper surface thereof may have a concavo-convex shape.

When folding of the rear plate <NUM> is performed in an opposite direction to folding of the flexible display unit <NUM>, interference may occur at the concavo-convex structure formed on the upper surface of the molding member <NUM>. As a result, folding of the rear plate <NUM> in the opposite direction to folding of the flexible display unit <NUM> may be restricted. That is, the molding member <NUM> may prevent counter-folding of the rear plate <NUM>.

The molding member <NUM> may maintain its parallel state when the flexible display unit <NUM> is unfolded, and may maintain its bent state when the flexible display unit <NUM> is folded. The molding member <NUM> may be formed of a material such as synthetic resin.

The aforementioned flexible display device is not limited to the configurations and the methods of the embodiments described above, but all or some of the embodiments may be selectively combined so that various modifications can be made.

Claim 1:
A flexible display device, comprising:
a first body (<NUM>);
a second body (<NUM>);
a flexible display unit (<NUM>) arranged on a surface of the first body (<NUM>) and the second body (<NUM>); and
a hinge unit (<NUM>) connecting the first body (<NUM>) and the second body (<NUM>) to each other such that the first body (<NUM>) and the second body (<NUM>) can be folded and unfolded with respect to each other,
wherein the hinge unit (<NUM>) includes a plurality of hinge segments (<NUM>) such that in a folding state of the flexible display unit (<NUM>), the second body (<NUM>) is arranged to cover a rear surface of the first body (<NUM>) as an interval between the hinge segments (<NUM>) is increased, and in an unfolded state of the flexible display unit (<NUM>), the first body (<NUM>) and the second body (<NUM>) are arranged in parallel with the interval between the hinge segments (<NUM>) being decreased,
characterised in that the flexible display device further comprises:
a rear plate (<NUM>, <NUM>) coupled to a rear surface of the flexible display unit (<NUM>), and configured to support the flexible display unit (<NUM>),
wherein the rear plate includes:
mounting portions (233a, 333a, 333a') extended in one direction, and recessed to couple the rear surface of the flexible display unit; and
a bending supporting portion (<NUM>, <NUM>) extended towards the outside from both sides of the mounting portions,
wherein the bending supporting portion (<NUM>, <NUM>) is concaved downward, and
wherein a metallic supporting member (<NUM>) is coupled to a bottom surface of the bending supporting portion (<NUM>, <NUM>), in correspondence to a shape of the bottom surface.