Patent Description:
Currently, display devices are regarded as essential electronic products. Electronic devices are required to be of compact size but many customers also desire large screens. Therefore, research and development are being actively conducted on flexible displays which are foldable or rollable into electronic devices.

<CIT> relates to a flexible display apparatus including: a flexible display panel; a housing including an opening through which the flexible display panel enters and exits the housing; a cylinder disposed within the housing to coil and uncoil the flexible display panel; and a stretcher that selectively extends from the opening to support the flexible display panel, such that the flexible display panel is substantially planar when the flexible display panel is extended outside of the housing.

<CIT> relates to a display device assembly comprising a flexible display device being rotatable around an axis, the flexible display having a front side and a back side, one of the sides being provided with distance means for preventing a direct contact between the front side and the back side, wherein the distance means comprises a protection foil.

<CIT> discloses a conventional film roll accumulating device for forming a filmstrip into a cylindrical film roll.

Provided are electronic devices capable of minimizing damage to flexible displays when the flexible displays extend out of or retract into the electronic devices.

According to an aspect of an embodiment, an electronic device is provided as defined by the appended set of claims.

According to an embodiment, when a flexible display extends out of an electronic device, a roll having the flexible display wound thereon may move to reduce a load applied to the flexible display.

Hereinafter, various embodiments of the present disclosure are described in detail with reference to the accompanying drawings. However, this description is not intended to limit the present disclosure to the described embodiments. In the drawings, like reference numerals denotes like elements.

As used herein, terms such as "have", "may have", "include", "may include", "comprise", and "may comprise" specify the presence of stated features (e.g., values, functions, operations, or elements), but do not preclude the presence or addition of one or more other features.

The expressions "A or B", "at least one of A or/and B", or "one or more of A or/and B" used herein include any and all combinations of one or more of the listed items. For example, "A or B", "at least one of A and B", or "at least one of A or B" means (<NUM>) including at least one A, (<NUM>) including at least one B, or (<NUM>) including both at least one A and at least one B.

Terms such as "1st", "2nd", "first", and "second" may be used herein to describe various elements regardless of order and/or priority thereof, but these elements should not be limited by these terms. For example, "a first user device" and "a second user device" may indicate different user devices regardless of order and/or priority thereof. For example, a first element could be termed a second element and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

It will be understood that when an element (e.g., first element) is referred to as being "(operatively or communicatively) coupled with/to" or "connected to" another element (e.g., second element), the element can be directly coupled or connected to the other element or an intervening element (e.g., third element) may be present. Conversely, when an element (e.g., first element) is referred to as being "directly coupled" or "directly connected" to another element (e.g., second element), there is no intervening element (e.g., third element) present.

The expression "configured to" may be interchangeably used with "suitable for", "having the capacity to", "designed to", "adapted to", "made to", or "capable of" according to the context. The expression "configured to" does not necessarily mean "specifically designed to" in terms of hardware. Instead, the expression "a device configured to. " may mean that the device is "capable of. " along with other devices or parts in a certain situation. For example, "a processor configured to perform A, B, and C" may mean a dedicated processor (e.g., an embedded processor) for performing the operations or a generic-purpose processor (e.g., a central processing unit (CPU) or application processor) for performing the operations by executing at least one software program stored in a memory device.

Terms used herein are used merely to describe certain embodiments and do not limit the scope of the present disclosure. Singular forms may include plural forms as well unless the context explicitly indicates otherwise. Unless defined differently, all terms used in the description including technical and scientific terms have the same meaning as generally understood by one of ordinary skill in the art. Terms as defined in a commonly used dictionary should be construed as having the same meaning as in an associated technical context, and unless defined in the description, the terms are not ideally or excessively construed as having formal meaning. In any case, even the terms defined in this specification cannot be interpreted as excluding embodiments of the present disclosure.

Electronic devices described herein according to various embodiments may include at least one of, for example, smartphones, tablet personal computers (PCs), mobile phones, video phones, electronic book (e-book) readers, desktop PCs, laptop PCs, netbook computers, workstations, servers, personal digital assistants (PDAs), portable multimedia player (PMPs), MP3 players, mobile medical devices, cameras, and wearable devices. According to various embodiments, the wearable devices may include at least one of accessory type wearable devices (e.g., watches, rings, bracelets, ankle bracelets, necklaces, glasses, and head-mounted-devices (HMDs)), textile/clothing type wearable devices (e.g., electronic apparel), body-attached wearable devices (e.g., skin pads and tattoos), and body-implantable wearable devices (e.g., implantable circuits).

In some embodiments, the electronic devices may be home appliances. The home appliances may include at least one of, for example, televisions (TVs), digital versatile disc (DVD) players, audio players, refrigerators, air conditioners, cleaners, washing machines, air cleaners, set-top boxes, home automation control panels, security control panels, TV boxes (e.g., Samsung HomeSync™, Apple TV™, and Google TV™), game consoles (e.g., Xbox™ and PlayStation™), electronic dictionaries, electronic keys, camcorders, and electronic picture frames.

In other embodiments, the electronic devices may include at least one of various medical devices (e.g., various portable medical measurement devices such as blood glucose meters, heart rate meters, blood pressure meters, and thermometers, magnetic resonance angiography (MRA) devices, magnetic resonance imaging (MRI) devices, computed tomography (CT) devices, scanners, and ultrasonic devices), navigation devices, global navigation satellite systems (GNSSs), event data recorders (EDRs), flight data recorders (FDRs), vehicle infotainment devices, electronic equipment for vessels (e.g., vessel navigation systems and gyrocompasses), avionics, security devices, vehicle head units, industrial or home robots, automatic teller machines (ATMs), point of sales (POS) devices, and Internet of Things (IoT) devices (e.g., lamps, various sensors, electricity or gas meters, sprinklers, fire alarms, thermostats, streetlamps, toasters, exercise equipment, hot water tanks, heaters, and boilers).

According to an embodiment, the electronic devices may include at least one of parts of furniture or buildings/structures, electronic boards, electronic signature receiving devices, projectors, or various measuring instruments (e.g., water meters, electricity meters, gas meters, and radio wave meters). In various embodiments, the electronic device may be one or a combination of two or more of the above-mentioned devices. The electronic device according to an embodiment may be a flexible electronic device. However, the electronic devices according to embodiments are not limited to the above-mentioned devices, but may include new electronic devices to be developed.

<FIG> is a block diagram of a network environment <NUM> including an electronic device <NUM> according to various embodiments.

Referring to <FIG>, the electronic device <NUM> may include a bus <NUM>, a processor <NUM>, a memory <NUM>, an input/output interface <NUM>, and a display <NUM>.

The bus <NUM> may be a circuit for interconnecting the above-mentioned elements and transmitting communication data (e.g., control messages) between the above-mentioned elements.

The processor <NUM> may, e.g., receive instructions from the above-mentioned other elements (e.g., the memory <NUM>, the input/output interface <NUM>, the display <NUM>, and a communication interface <NUM>) through the bus <NUM>, interpret the received instructions, and perform calculation or data processing based on the interpreted instructions.

The memory <NUM> may store instructions or data received from the processor <NUM> or the other elements (e.g., the input/output interface <NUM>, the display <NUM>, and the communication interface <NUM>) or generated by the processor <NUM> or the other elements. The memory <NUM> may include programming modules, e.g., a kernel <NUM>, middleware <NUM>, an application programming interface (API) <NUM>, and applications <NUM>. Each of the above-mentioned programming modules may be configured as software, firmware, hardware, or a combination of two or more thereof.

The kernel <NUM> may control or manage system resources (e.g., the bus <NUM>, the processor <NUM>, or the memory <NUM>) which are used to perform operations or functions implemented in the other programming modules, e.g., the middleware <NUM>, the API <NUM>, or the applications <NUM>. In addition, the kernel <NUM> may provide an interface for allowing the middleware <NUM>, the API <NUM>, or the applications <NUM> to access and control or manage each element of the electronic device <NUM>.

The middleware <NUM> may serve as a relay for allowing the API <NUM> or the applications <NUM> to communicate and exchange data with the kernel <NUM>. In addition, the middleware <NUM> may control (e.g., schedule or load-balance) operation requests received from the applications <NUM> by, for example, giving a priority of using the system resources (e.g., the bus <NUM>, the processor <NUM>, or the memory <NUM>) of the electronic device <NUM> to at least one of the applications <NUM>.

The API <NUM> may be an interface for allowing the applications <NUM> to control a function provided by the kernel <NUM> or the middleware <NUM>, and may include at least one interface or function (e.g., an instruction) for, for example, file control, window control, image processing, or text control.

According to various embodiments, the applications <NUM> may include a short message service (SMS)/multimedia message service (MMS) application, an e-mail application, a calendar application, an alarm application, a healthcare application (e.g., an application for measuring a workrate or a blood glucose level), and an environmental information application (e.g., an application for providing information about atmospheric pressure, humidity, or temperature). Additionally or alternatively, the applications <NUM> may be applications related to information exchange between the electronic device <NUM> and an external electronic device (e.g., an electronic device <NUM>). The application related to information exchange may include, for example, a notification relay application for transmitting certain information to the external electronic device or a device management application for managing the external electronic device.

For example, the notification relay application may include a function for transmitting notification information generated from the other application of the electronic device <NUM> (e.g., the SMS/MMS application, the e-mail application, the health management application, or the environmental information application), to the external electronic device (e.g., the electronic device <NUM>). Additionally or alternatively, the notification relay application may receive notification information from, for example, the external electronic device (e.g., the electronic device <NUM>) and provide the received notification information to a user. The device management application may manage (e.g., install, delete, or update), for example, functions related to at least a part of the external electronic device (e.g., the electronic device <NUM>) communicating with the electronic device <NUM> (e.g., functions for turning on/off the external electronic device (or some parts thereof) or adjusting brightness (or resolution) of a display), and applications operating in the external electronic device or services provided by the external electronic device (e.g., a call service or a message service).

According to various embodiments, the applications <NUM> may include an application that is designated based on properties (e.g., the type) of the external electronic device (e.g., the electronic device <NUM>). For example, when the external electronic device is an MP3 player, the applications <NUM> may include an application related to reproduction of music. Similarly, when the external electronic device is a mobile medical device, the applications <NUM> may include an application related to healthcare. According to an embodiment, the applications <NUM> may include at least one of an application designated for the electronic device <NUM> and an application received from an external electronic device (e.g., a server <NUM> or the electronic device <NUM>).

The input/output interface <NUM> may transmit an instruction or data input from the user through an input/output device (e.g., a sensor, a keyboard, or a touchscreen) to the processor <NUM>, the memory <NUM>, or the communication interface <NUM> through, for example, the bus <NUM>. For example, the input/output interface <NUM> may provide, to the processor <NUM>, data about the user's touch input through the touchscreen. In addition, the input/output interface <NUM> may output, through an input/output device (e.g., a speaker or a display), an instruction or data received from the processor <NUM>, the memory <NUM>, or the communication interface <NUM> through, for example, the bus <NUM>. For example, the input/output interface <NUM> may output voice data processed by the processor <NUM>, to the user through the speaker.

The display <NUM> may display various types of information (e.g., multimedia data and text data) to the user. The display <NUM> may include, for example, a liquid crystal display (LCD), a light-emitting diode (LED) display, an organic light-emitting diode (OLED) display, a microelectromechanical system (MEMS) display, an electronic paper display, or a flexible display. The display <NUM> may, for example, display various contents (e.g., text, images, videos, icons, and symbols) to the user. The display <NUM> may include a touchscreen and may receive, for example, touches, gestures, proximity touches, or hovering inputs using an electronic pen or a body part of the user.

The electronic device <NUM> may further include the communication interface <NUM>. The communication interface <NUM> may establish a communication connection between the electronic device 101and the external device (e.g., the electronic device <NUM> or the server <NUM>). For example, the communication interface <NUM> may be connected to a network <NUM> through wireless or wired communication to communicate with the external device. The wireless communication technology may include at least one of, for example, wireless fidelity (Wi-Fi), Bluetooth (BT), near field communication (NFC), global positioning system (GPS), and cellular communication (e.g., long term evolution (LTE), LTE-advanced (LTE-A), code division multiple access (CDMA), wideband CDMA (WCDMA), universal mobile telecommunication system (UMTS), wireless-broadband (WiBro), and global system for mobile communications (GSM)). The wired communication technology may include at least one of, for example, universal serial bus (USB), high definition multimedia interface (HDMI), recommended standard <NUM> (RS-<NUM>), and plain old telephone service (POTS).

According to an embodiment, the network <NUM> may be a telecommunications network. The telecommunications network may include at least one of a computer network, the Internet, the Internet of things, or a telephone network. According to an embodiment, a protocol (e.g., a transport layer protocol, a data link layer protocol, or a physical layer protocol) for communication between the electronic device <NUM> and the external device may be supported by at least one of the applications <NUM>, the API <NUM>, the middleware <NUM>, the kernel <NUM>, and the communication interface <NUM>.

<FIG> is a perspective view of the electronic device <NUM> according to an embodiment. <FIG> is a perspective view of a roll <NUM> included in the electronic device <NUM>, and a flexible display <NUM> wound on the roll <NUM>.

Referring to <FIG> and <FIG>, the electronic device <NUM> includes a housing <NUM>, the roll <NUM> on which the flexible display <NUM> is wound, and the flexible display <NUM> wound on the roll <NUM> to retract into the housing <NUM> or unwound from the roll <NUM> to extend out of the housing <NUM>.

The electronic device <NUM> has a structure capable of accommodating the flexible display <NUM> in the housing <NUM> in a wound state, and of extending and spreading the display <NUM> out of the housing <NUM> as necessary to provide information to a user.

To this end, an opening <NUM> is provided in a surface or at a side of the housing <NUM>. When unwound from the roll <NUM>, the flexible display <NUM> extends out of the electronic device <NUM> through the opening <NUM> of the housing <NUM>. When wound on the roll <NUM>, the flexible display <NUM> retracts into the housing <NUM> through the opening <NUM>.

An end of the flexible display <NUM> is connected to the roll <NUM>. The flexible display <NUM> may be connected to the roll <NUM> directly or through a medium for transmitting signals between the flexible display <NUM> and the electronic device <NUM>.

The roll <NUM> is configured to rotate in the housing <NUM> to wind the flexible display <NUM> on a body of the roll <NUM>. A handle <NUM> holdable by the user to extend the flexible display <NUM> out of the housing <NUM> may be provided at the other end of the flexible display <NUM>.

A side protector <NUM> is provided at a width-direction side and the other width-direction side of the flexible display <NUM>. The side protector <NUM> may protect the flexible display <NUM> from external impact. The side protector <NUM> may be thicker than the flexible display <NUM>.

Referring to <FIG>, when the flexible display <NUM> is wound on the roll <NUM> in a multilayer structure, a distance between an inner layer <NUM> and an outer layer <NUM> may be constantly maintained such that an outer surface of the inner layer <NUM> may not contact an inner surface of the outer layer <NUM>. As such, wear and damage of the surface of the flexible display <NUM>, i.e., a display surface on which an image is displayed, may be reduced.

A central shaft <NUM> of the roll <NUM> is rotatably supported in the housing <NUM>. The roll <NUM> rotates with respect to the central shaft <NUM> of the roll <NUM> in the housing <NUM>. The electronic device <NUM> may further include a winder <NUM> for rotating the roll <NUM>. The winder <NUM> may be connected from outside the housing <NUM> to the central shaft <NUM> directly or through a motive power transmission device such as a gear, but is not limited thereto. The flexible display <NUM> may be wound on the roll <NUM> by rotating the roll <NUM> by using the winder <NUM>.

When the roll <NUM> rotates, the flexible display <NUM> connected to the roll <NUM> is wound on or unwound from the roll <NUM>. For example, when the user pulls the handle <NUM>, the roll <NUM> rotates in a counterclockwise direction and the flexible display <NUM> is unwound from the roll <NUM> and extends out of the housing <NUM>. When the user rotates the winder <NUM> connected to the central shaft <NUM> of the roll <NUM>, the roll <NUM> rotates in a clockwise direction. Then, the flexible display <NUM> is wound on the roll <NUM> and retracts into the housing <NUM>.

A stopper <NUM> may be mounted on a region of the flexible display <NUM> or on a region of the side protector <NUM>. An area of the flexible display <NUM> extending out of the housing <NUM> may be determined based on a location of the stopper <NUM>. For example, referring to <FIG>, the stopper <NUM> may be mounted adjacent to the end of the flexible display <NUM> connected to the roll <NUM>. As such, the flexible display <NUM> may extend outside only to where the stopper <NUM> is mounted.

In the electronic device <NUM> according to an embodiment, a part from where the stopper <NUM> is mounted to where the handle <NUM> is provided may be configured as the flexible display <NUM> and a part from where the flexible display <NUM> is connected to the roll <NUM> to where the stopper <NUM> is mounted may be configured as a component for transmitting electronic signals between the processor <NUM> and the flexible display <NUM> of the electronic device <NUM>. In other words, in the flexible display <NUM>, a region from where the stopper <NUM> is mounted to the other end where the handle <NUM> is provided may be an image display area for displaying an image, and a region from the end connected to the roll <NUM> to where the stopper <NUM> is mounted may be a signal transmission area on which a flexible printed circuit board (FPCB) or the like is provided to transmit/receive signals to/from the processor <NUM>.

When the flexible display <NUM> is wound on or unwound from the roll <NUM>, a distance from a center of the roll <NUM> to the flexible display <NUM> wound on the roll <NUM>, i.e., an outer diameter of the roll <NUM>, is increased or reduced. As such, although not shown in <FIG> and <FIG>, the flexible display <NUM> moves in a direction almost perpendicular to a direction in which the flexible display <NUM> is unwound from or wound on the roll <NUM>, i.e., a radius direction of the roll <NUM>. The movement of the flexible display <NUM> in the radius direction may cause shaking of a screen.

<FIG> is a side cross-sectional view showing that the flexible display <NUM> is wound or unwound when the roll <NUM> rotates at a fixed location. As illustrated in <FIG>, when the opening <NUM> of the housing <NUM> does not have a sufficient height, a proceeding direction of the flexible display <NUM> with respect to the opening <NUM> in the housing <NUM> may be continuously changed and thus the opening <NUM> may be damaged.

In a first state in which the flexible display <NUM> is completely wound on the roll <NUM> as indicated by a solid line in <FIG>, the flexible display <NUM> passes through the opening <NUM> in an almost horizontal direction. However, in a second state in which the flexible display <NUM> is completely unwound from the roll <NUM> as indicated by a two-dot chain line in <FIG>, the flexible display <NUM> passes through the opening <NUM> in a direction inclined with respect to the direction of the first state by an angle α. Since the flexible display <NUM> is repeatedly bent while extending/retracting, fatigue may be accumulated and thus the flexible display <NUM> may be damaged.

A method capable of reducing repeated bending of the flexible display <NUM> in a direction perpendicular to a direction of the flexible display <NUM> that enters and exits the housing <NUM> through the opening <NUM>, and of constantly maintaining a proceeding direction of the flexible display <NUM> with respect to the opening <NUM> in the housing <NUM> is considered.

As an example of the method according to the claimed invention, the roll <NUM> may be supported in the housing <NUM> to move in a direction capable of compensating for a variation in the outer diameter thereof. The roll <NUM> is guided by a roll guide <NUM> provided in the housing <NUM>. The roll guide <NUM> may have, for example, a slot shape, and two ends of the central shaft <NUM> of the roll <NUM> are inserted into a pair of roll guides <NUM>. Due to the above-described configuration, the roll <NUM> may move along the roll guide <NUM> in accordance with the variation in the outer diameter thereof. The movement of the roll <NUM> may occur simultaneously with rotation of the roll <NUM>.

Embodiments of a structure in which the roll <NUM> moves in accordance with a variation in a wound length of the flexible display <NUM> on the roll <NUM> will now be described.

<FIG> are side cross-sectional views of the electronic device <NUM> according to an embodiment. <FIG> shows a state in which the flexible display <NUM> is completely wound on the roll <NUM>, and <FIG> shows a state in which the flexible display <NUM> is completely unwound from the roll <NUM>.

Referring to <FIG>, an end of the flexible display <NUM> is connected to the roll <NUM> and the other end thereof is connected to the handle <NUM>. The flexible display <NUM> is wound on the roll <NUM> and is positioned in the housing <NUM>. When the flexible display <NUM> extends out of the housing <NUM>, the roll <NUM> and the central shaft <NUM> rotate together. In this case, the roll <NUM> may rotate with respect to the central shaft <NUM>, and the central shaft <NUM> may be supported by the housing <NUM> to move along the roll guide <NUM>. Referring to <FIG>, the flexible display <NUM> is unwound from the roll <NUM> and extends out of the housing <NUM>.

When the flexible display <NUM> extends out of the housing <NUM>, an outer diameter of the roll <NUM> varies. When the outer diameter of the roll <NUM> in <FIG> is D1, the outer diameter of the roll <NUM> in <FIG> is D2 less than D1. The roll guide <NUM> guides the roll <NUM> in such a manner that the roll <NUM> moves to compensate for a variation (D1-D2) in the outer diameter of the roll <NUM>. Herein, each of the outer diameters D1 and D2 refers to a total outer diameter including the flexible display <NUM> wound on the roll <NUM>.

In <FIG>, the roll guide <NUM> guides the central shaft <NUM> in such a manner that the roll <NUM> moves downward as the flexible display <NUM> extends from the housing <NUM>. In the current embodiment, a display guide <NUM> is positioned under the roll <NUM> in the direction of gravity, and supports the flexible display <NUM> wound on the roll <NUM>. The display guide <NUM> extends toward the opening <NUM> in a direction equal to a direction in which the flexible display <NUM> extends out of the housing <NUM>. The display guide <NUM> is provided adjacent to the opening <NUM>.

Although the display guide <NUM> is positioned at a lower side in the direction of gravity in the following description for convenience of explanation, the electronic device <NUM> may be used in a state in which the central shaft <NUM> of <FIG> stands upright in the direction of gravity. In this case, the location of the display guide <NUM> is not under the roll <NUM> in the direction of gravity, and the display guide <NUM> may extend toward the opening <NUM> in a direction equal to a direction in which the flexible display <NUM> extends out of the housing <NUM>.

When the flexible display <NUM> extends or retracts, the display guide <NUM> may contact the surface of the flexible display <NUM> or the side protector <NUM> of the flexible display <NUM> to reduce shaking of the flexible display <NUM>. Therefore, as the flexible display <NUM> is unwound from the roll <NUM>, the roll <NUM> is guided by the roll guide <NUM> to move downward and a movement distance thereof is limited by the display guide <NUM>.

The display guide <NUM> guides the flexible display <NUM> toward the opening <NUM>. The display guide <NUM> of the current embodiment guides the flexible display <NUM> to pass through the opening <NUM> in a horizontal direction. To this end, a supporting surface <NUM> of the display guide <NUM>, which supports the flexible display <NUM>, extends toward the opening <NUM>.

As such, a proceeding direction of a part of the flexible display <NUM> positioned in the housing <NUM>, i.e., a part of the flexible display <NUM> between the roll <NUM> and the opening <NUM>, may be constantly maintained as a certain direction, e.g., a horizontal direction. Although not shown in <FIG>, when the electronic device <NUM> is used in a state in which the central shaft <NUM> stands upright in the direction of gravity, the proceeding direction of the flexible display <NUM> may be constantly maintained as a vertical direction.

The roll guide <NUM> extends in the direction of gravity, i.e., a direction almost perpendicular to a proceeding direction of the flexible display <NUM> unwound from the roll <NUM> and proceeding toward the opening <NUM> in the housing <NUM>, in <FIG>, but is not limited thereto. The roll guide <NUM> may have various shapes capable of compensating for the variation (D1-D2) in the outer diameter of the roll <NUM>.

<FIG> is a side cross-sectional view of the electronic device <NUM> according to an embodiment.

Referring to <FIG>, the roll guide <NUM> is inclined downward with respect to the direction of gravity. In other words, the roll guide <NUM> is inclined with respect to a proceeding direction of the flexible display <NUM> unwound from the roll <NUM> and proceeding toward the opening <NUM> in the housing <NUM>. In this case, the inclined direction of the roll guide <NUM> may be a direction toward the opening <NUM>. As such, a distance between the roll <NUM> and the opening <NUM> may be reduced and thus a length of an effective image display area of the flexible display <NUM> may be increased.

Since the roll <NUM> rotates and moves as described above, the flexible display <NUM> unwound from the roll <NUM> may always proceed toward the opening <NUM> in the same direction. That is, a part of the flexible display <NUM> between the roll <NUM> and the opening <NUM> may constantly maintain the same proceeding direction toward the opening <NUM> in a state in which the flexible display <NUM> is positioned in the housing <NUM>, a state in which a part of the flexible display <NUM> extends out of the housing <NUM>, and a state in which an extendable area of the flexible display <NUM> completely extends out of the housing <NUM>.

The proceeding direction of the flexible display <NUM> for interconnecting the roll <NUM> and the opening <NUM> may not be a horizontal direction. <FIG> is a side cross-sectional view of the electronic device <NUM> according to embodiment.

Referring to <FIG>, the display guide <NUM> includes a supporting surface <NUM> inclined with respect to a horizontal direction. For example, in the current embodiment, the supporting surface <NUM> is inclined downward toward the opening <NUM>. Due to the above-described configuration, as the flexible display <NUM> is unwound from the roll <NUM>, the roll <NUM> may be naturally guided by the roll guide <NUM> to move downward, and the flexible display <NUM> unwound from the roll <NUM> may be guided along the supporting surface <NUM> to extend out of the housing <NUM> through the opening <NUM>.

Therefore, a proceeding direction of a part of the flexible display <NUM> between the roll <NUM> and the opening <NUM> may be constantly maintained. A guide member <NUM> for guiding the proceeding direction of the flexible display <NUM> passing through the opening <NUM> is provided at an upper side of the opening <NUM> with respect to a direction in which the flexible display <NUM> is unwound.

The guide member <NUM> guides the flexible display <NUM> at a side opposite to the display guide <NUM> with respect to the flexible display <NUM> interposed between the guide member <NUM> and the display guide <NUM>. The guide member <NUM> may, for example, guide the flexible display <NUM> to proceed in a horizontal direction after passing through the opening <NUM>.

Inclination of the guide member <NUM> may be designed in consideration of a curvature by which the flexible display <NUM> is bendable. That is, the inclination of the guide member <NUM> may be designed to have a curvature greater than the maximum curvature of the flexible display <NUM>. As such, even when the flexible display <NUM> bent by a certain curvature by the guide member <NUM> passes through the opening <NUM>, fatigue due to the bending may not accumulated in the flexible display <NUM>.

Referring to <FIG>, a push member <NUM> is illustrated. The roll <NUM> is positioned between the display guide <NUM> and the push member <NUM>. The push member <NUM> pushes the roll <NUM> toward the display guide <NUM> in such a manner that the flexible display <NUM> wound on the roll <NUM> contacts the supporting surface <NUM>.

In <FIG>, the push member <NUM> pushes the flexible display <NUM> wound on the roll <NUM>. The push member <NUM> may contact the flexible display <NUM> or the side protector <NUM>. The push member <NUM> may be provided in the form of a roller that rotates as the roll <NUM> rotates, to reduce frictional contact with the flexible display <NUM> or the side protector <NUM> (see <FIG>).

The push member <NUM> may push the roll <NUM> toward the display guide <NUM> due to a self weight thereof. As illustrated in <FIG>, an elastic member <NUM> for applying elastic force to the push member <NUM> in a direction capable of pushing the roll <NUM> toward the display guide <NUM> may be further provided.

The display guide <NUM> supports the flexible display <NUM> wound on the roll <NUM>, and guides the flexible display <NUM> unwound from the roll <NUM>, toward the opening <NUM>.

The flexible display <NUM> may be pushed by the push member <NUM> and supported by the display guide <NUM> and thus may be stably held in a wound state on the roll <NUM>. In addition, even when the flexible display <NUM> is wound on or unwound from the roll <NUM>, the push member <NUM> aids stable extension and retraction of the flexible display <NUM> by reducing movement of the roll <NUM> in directions other than a direction in which the roll <NUM> is rolled or unrolled.

A structure in which the roll <NUM> is pushed toward the display guide <NUM> by using the push member <NUM> and the elastic member <NUM> may be applied to the embodiment of <FIG> such that the flexible display <NUM> wound on the roll <NUM> may be pushed toward the supporting surface <NUM> of the display guide <NUM>.

<FIG> and <FIG> are side cross-sectional views of the electronic device <NUM> according to an embodiment. The electronic device <NUM> of the current embodiment may include a winding member for providing elastic force to the roll <NUM> in such a manner that the roll <NUM> rotates in a direction capable of winding the flexible display <NUM> thereon. Referring to <FIG> and <FIG>, the winding member may be implemented by, for example, a spiral spring <NUM>.

An end of the spiral spring <NUM> may be connected to the roll <NUM>, and the other end thereof may be connected to the housing <NUM>. Alternatively, the end of the spiral spring <NUM> may be connected to the roll <NUM> and the other end thereof may be connected to the central shaft <NUM>. In this case, the roll <NUM> has a structure rotatable with respect to the central shaft <NUM>, and the central shaft <NUM> does not rotate with respect to the housing <NUM> but is merely supported by the housing <NUM> to move along the roll guide <NUM>. In the current embodiment, the other end of the spiral spring <NUM> is connected to the central shaft <NUM>.

Referring to <FIG>, when the flexible display <NUM> starts to extend out of the housing <NUM>, the roll <NUM> rotates in a counterclockwise direction. The spiral spring <NUM> accumulates elastic force as the roll <NUM> rotates. The elastic force accumulated by the spiral spring <NUM> is used to retract the flexible display <NUM> extended out of the housing <NUM>, into the housing <NUM> to wind the flexible display <NUM> on the roll <NUM>.

The electronic device <NUM>, which retracts the flexible display <NUM> into the housing <NUM> by using the spiral spring <NUM>, may include a locking unit capable of holding the flexible display <NUM> in an extended state. <FIG> is a structural view of a locking unit according to an embodiment.

Referring to <FIG>, the locking unit may be implemented by a stopper projection <NUM> and a stopper lever <NUM>. The stopper projection <NUM> is provided on the roll <NUM>. The stopper projection <NUM> may be provided at a side or two sides of the roll <NUM>. As necessary, a plurality of stopper projections <NUM> may be provided in a rotation direction of the roll <NUM>. The number of stopper projections <NUM> may be determined in consideration of a diameter of the roll <NUM> or a length of the flexible display <NUM>. For example, when the plurality of stopper projections <NUM> are provided, a length of the flexible display <NUM> extending out of the housing <NUM> may be adjusted in multiple stages.

The stopper lever <NUM> may be provided on the housing <NUM>. Alternatively, in a structure in which the central shaft <NUM> is supported by the housing <NUM> and the roll <NUM> rotates with respect to the central shaft <NUM>, the stopper lever <NUM> may be provided on the central shaft <NUM>. In the current embodiment, the stopper lever <NUM> is provided on the central shaft <NUM>.

An end of the stopper lever <NUM> is rotatably supported by the central shaft <NUM>. The stopper lever <NUM> may rotate to a contact location (indicated by a solid line in <FIG>) at which the other end of the stopper lever <NUM> contacts the stopper projection <NUM>, and a release location (indicated by a two-dot chain line in <FIG>) at which the other end of the stopper lever <NUM> is released from the stopper projection <NUM>. The spring <NUM> provides elastic force to the stopper lever <NUM> in a direction capable of holding the stopper lever <NUM> at the contact location.

Referring to <FIG>, when the roll <NUM> rotates in a counterclockwise direction to extend the flexible display <NUM> out of the housing <NUM>, the stopper projection <NUM> contacts the stopper lever <NUM> mounted on the central shaft <NUM>. In this state, when the roll <NUM> further rotates in the counterclockwise direction, the stopper lever <NUM> is pushed by the stopper projection <NUM> and rotates in a direction opposite to a direction of the elastic force of the spring <NUM>.

As the stopper lever <NUM> is pushed by the stopper projection <NUM> and rotates, a length of a superposed part between the stopper lever <NUM> and the stopper projection <NUM> is gradually reduced. When the roll <NUM> further rotates in the counterclockwise direction, the stopper lever <NUM> is positioned at the release location, the stopper projection <NUM> is released from the stopper lever <NUM>, and the roll <NUM> may continuously rotate in the counterclockwise direction. The stopper lever <NUM> returns to the contact location due to the elastic force of the spring <NUM>.

When the roll <NUM> stops rotating in the counterclockwise direction, the roll <NUM> rotates in a clockwise direction due to the elastic force of the spiral spring <NUM>. As the roll <NUM> rotates in the clockwise direction, the stopper projection <NUM> contacts the stopper lever <NUM>. The stopper lever <NUM> may rotate from the contact location to the release location, but is restricted so as not to rotate beyond the contact location. A restriction member for the restriction may be implemented by, for example, a restriction slot <NUM> provided in the central shaft <NUM>, and a restriction protrusion <NUM> provided on the stopper lever <NUM> and inserted into the restriction slot <NUM>. Accordingly, when the stopper projection <NUM> rotates in the clockwise direction and contacts the stopper lever <NUM> positioned at the contact location, the roll <NUM> may no more rotate in the clockwise direction and the display <NUM> is held in an extended state.

The electronic device <NUM> needs to release a locked state of the stopper lever <NUM> and the stopper projection <NUM> to retract the held display <NUM> into the housing <NUM>. For example, the electronic device <NUM> may rotate the stopper lever <NUM> to the release location. To this end, although not shown in <FIG>, to allow a user to manually manipulate and rotate the stopper lever <NUM> to the release location, a part of the stopper lever <NUM> may be exposed outside the housing <NUM>. In addition, although not shown in <FIG>, a release lever for manually manipulating and rotating the stopper lever <NUM> exposed outside the housing <NUM>, to the release location may be further provided.

<FIG> are side cross-sectional views of the electronic device <NUM> according to an embodiment.

Referring to <FIG>, the push member <NUM> may be implemented by a roll spring <NUM>. The roll spring <NUM> is supported by the roll guide <NUM> and pushes the roll <NUM> toward the display guide <NUM>. The roll spring <NUM> pushes the central shaft <NUM>.

The flexible display <NUM> wound on the roll <NUM> is held in contact with the display guide <NUM>, by the roll spring <NUM>. Therefore, the flexible display <NUM> may be held in a wound state on the roll <NUM>. In addition, as the flexible display <NUM> is unwound from the roll <NUM>, the roll <NUM> may more easily move downward and the flexible display <NUM> may be held in contact with the display guide <NUM>.

The push member <NUM> and the elastic member <NUM> of <FIG> may be applied to the electronic device <NUM> illustrated in <FIG>. As such, the flexible display <NUM> may be more stably held in a wound state on the roll <NUM>.

The electronic device <NUM> illustrated in <FIG> may include a spiral spring (not shown) between the roll <NUM> and the central shaft <NUM>. The spiral spring may be provided at the same location as and may perform the same function as the spiral spring <NUM> described above in relation to <FIG> and <FIG>.

The electronic device <NUM>, which retracts the flexible display <NUM> into the housing <NUM> by using the spiral spring <NUM>, may include a locking unit capable of holding the flexible display <NUM> in an extended state. The locking unit may hold the extended flexible display <NUM>. The locking unit may be implemented by the stopper projection <NUM> and the stopper lever <NUM> described above in relation to <FIG>.

When the flexible display <NUM> enters and exits the housing <NUM> through the opening <NUM>, a certain relationship may be established between rotation of the roll <NUM> and movement of the roll <NUM> along the roll guide <NUM>.

Referring to <FIG>, a pinion gear <NUM> is illustrated. The pinion gear <NUM> may be provided on, for example, the roll <NUM>. In a structure in which the central shaft <NUM> rotates together with the roll <NUM>, the pinion gear <NUM> may be provided on the central shaft <NUM>. In the current embodiment, the pinion gear <NUM> is provided on the central shaft <NUM>. The pinion gear <NUM> engages with a rack gear <NUM> extending in a movement direction of the roll <NUM>, i.e., an extension direction of the roll guide <NUM>. The rack gear <NUM> is positioned at a fixed location. For example, the rack gear <NUM> may be provided on the housing <NUM>. As the flexible display <NUM> is wound on or unwound from the roll <NUM>, the pinion gear <NUM> may move along the rack gear <NUM> in an extension direction of the rack gear <NUM>.

The pinion gear <NUM> may be designed to move along the rack gear <NUM> by a variation in an outer diameter of the roll <NUM> including the flexible display <NUM>, when the flexible display <NUM> is wound on the roll <NUM> in a multilayer structure. That is, when the flexible display <NUM> wound on the roll <NUM> is unwound or further wound by a layer, the roll <NUM> may move along the roll guide <NUM> by a thickness of the flexible display <NUM> such that a proceeding direction of the flexible display <NUM> with respect to the opening <NUM> may be constantly maintained.

When a diameter of the pinion gear <NUM> is Dp, the number of turns of the pinion gear <NUM> is Np, and a movement distance of the pinion gear <NUM> along the rack gear <NUM> is L,<MAT>
is satisfied.

Referring to <FIG>, the pinion gear <NUM> moves along the rack gear <NUM> and is positioned at a location under the location of <FIG>, and the flexible display <NUM> is in an extended state. As described above, the pinion gear <NUM> may move by an increase or a reduction in the thickness of the flexible display <NUM> wound on or unwound from the roll <NUM>. Therefore, while the roll <NUM> is moving together with the pinion gear <NUM>, a proceeding direction of the flexible display <NUM> toward the opening <NUM> may be constantly maintained.

The electronic device <NUM> according to the current embodiment may include a display guide (not shown), a push member (not shown), and an elastic member (not shown) for appropriate extension and retraction of the flexible display <NUM>. The display guide, the push member, and the elastic member of the current embodiment may be provided at the same locations as and may perform the same functions as the display guide <NUM>, the push member <NUM>, and the elastic member <NUM> described above in relation to <FIG>.

The electronic device <NUM> according to the current embodiment may include a spiral spring (not shown) for interconnecting the roll <NUM> and the central shaft <NUM>. The spiral spring of the current embodiment may be provided at the same location as and may perform the same function as the spiral spring <NUM> described above in relation to <FIG> and <FIG>.

The electronic device <NUM>, which retracts the flexible display <NUM> into the housing <NUM> by using the spiral spring <NUM>, may include a locking unit capable of holding the flexible display <NUM> in an extended state. The locking unit may hold the extended flexible display <NUM>. The locking unit may employ a structure of the stopper projection <NUM> and the stopper lever <NUM> described above in relation to <FIG>.

In a structure including only the rack gear <NUM> and the pinion gear <NUM>, the diameter of the pinion gear <NUM> is reduced in proportion to the thickness of the flexible display <NUM>. Therefore, in consideration of production errors and durability of the pinion gear <NUM>, a gear reduction structure may be interposed between the rack gear <NUM> and the pinion gear <NUM>.

<FIG> is a structural view of a reduction structure according to an embodiment.

Referring to <FIG>, a reduction gear <NUM> is interposed between the pinion gear <NUM> and the roll <NUM>.

The reduction gear <NUM> is a double gear including a first gear part <NUM> engaging with the pinion gear <NUM>, and a second gear part <NUM> engaging with the rack gear <NUM>. A diameter of the first gear part <NUM> is greater than a diameter of the second gear part <NUM>. Although not shown in <FIG>, the reduction gear <NUM> may be provided on a bracket (not shown) for rotatably supporting the roll <NUM>. The bracket is supported by the housing <NUM> to move together with the roll <NUM>.

When the diameter of the first gear part <NUM> is D1 and the diameter of the second gear part <NUM> is D2, the pinion gear <NUM> is connected to the rack gear <NUM> at a reduction gear ratio of D2/D1. Therefore, when a diameter of the pinion gear <NUM> is Dp1, a movement distance of the roll <NUM> is L1, and the number of turns of the pinion gear <NUM> is Np,
<MAT>
is satisfied.

Herein, if L of Equation (<NUM>) equals L1 of Equation (<NUM>), the diameter Dp1 of the pinion gear <NUM> satisfies.

Dp1 = (D1/D2)*Dp. Since D1>D2, Dp1>Dp is satisfied. Therefore, since the diameter of the pinion gear <NUM> may be increased by (D1/D2) times, the pinion gear <NUM> having a size appropriate for production may be employed by appropriately selecting the diameters of the first and second gear parts <NUM> and <NUM>, and durability of the pinion gear <NUM> may be increased.

As necessary, two or more reduction gears may be employed. <FIG> is a structural view of a reduction structure according to an embodiment. Referring to <FIG>, first and second reduction gears <NUM> and <NUM> are interposed between the pinion gear <NUM> and the rack gear <NUM>.

The first reduction gear <NUM> is a double gear including first and second gear parts <NUM> and <NUM>. The second reduction gear <NUM> is a double gear including third and fourth gear parts <NUM> and <NUM>. The first gear part <NUM> engages with the pinion gear <NUM>. The second gear part <NUM> engages with the third gear part <NUM>. The fourth gear part <NUM> engages with the rack gear <NUM>.

A diameter of the first gear part <NUM> is greater than a diameter of the second gear part <NUM>. A diameter of the third gear part <NUM> is greater than a diameter of the fourth gear part <NUM>. Although not shown in <FIG>, the first and second reduction gears <NUM> and <NUM> may be provided on a bracket (not shown) for rotatably supporting the roll <NUM>. The bracket is supported by the housing <NUM> to move together with the roll <NUM>.

When the diameters of the first, second, third, and fourth gear parts <NUM>, <NUM>, <NUM>, and <NUM> are D1, D2, D3, and D4, respectively, the pinion gear <NUM> is connected to the rack gear <NUM> at a reduction gear ratio of (D2/D1)*(D4/D3). Therefore, when a diameter of the pinion gear <NUM> is Dp2, a movement distance of the roll <NUM> is L2, and the number of turns of the pinion gear <NUM> is Np,
<MAT>
is satisfied.

Herein, if L of Equation (<NUM>) equals L2 of Equation (<NUM>), the diameter Dp1 of the pinion gear <NUM> satisfies Dp2 = (D1/D2)*(D3/D4)*Dp. Since D1>D2 and D3>D4, Dp2>Dp is satisfied. Therefore, since the diameter of the pinion gear <NUM> may be increased by (D1/D2)*(D3/D4) times, the pinion gear <NUM> having a size appropriate for production may be employed by appropriately selecting the diameters of the first to fourth gear parts <NUM>, <NUM>, <NUM>, and <NUM>, and durability of the pinion gear <NUM> may be increased. In addition, since gear reduction occurs twice, when Dp1 equals Dp2, the first and second reduction gears <NUM> and <NUM> may have sizes less than a size of the reduction gear <NUM> and thus a compact gear reduction structure applicable to a small space may be implemented.

<FIG> includes perspective views showing usage of the electronic device <NUM> using the afore-described structures. Herein, the electronic device <NUM> may be, for example, a rollable TV or screen.

Referring to <FIG>, the electronic device <NUM> may be fixed to a wall in such a manner that the opening <NUM> faces downward. The flexible display <NUM> is completely wound on the roll <NUM> and accommodated in the housing <NUM>. The roll <NUM> is positioned, for example, at a rear end of the roll guide <NUM>. A user may extend the flexible display <NUM> out of the housing <NUM> by holding and pulling downward the handle <NUM> positioned at a front end of the flexible display <NUM>.

<FIG> shows that the flexible display <NUM> partially extends downward through the opening <NUM> of the housing <NUM>. <FIG> shows that the flexible display <NUM> mostly extends downward through the opening <NUM> of the housing <NUM>. As illustrated in <FIG>, the roll <NUM> moves forward along the roll guide <NUM> as the flexible display <NUM> is unwound from the roll <NUM> and extends through the opening <NUM>, and reaches a front end of the roll guide <NUM> when the flexible display <NUM> completely extends. When the flexible display <NUM> is wound on the roll <NUM>, a wound length of the flexible display <NUM> on the roll <NUM> is increased and the roll <NUM> moves backward along the roll guide <NUM>. Therefore, even when the wound length of the flexible display <NUM> on the roll <NUM> varies, a proceeding direction of the flexible display <NUM> with respect to the opening <NUM> in the housing <NUM> may be constantly maintained.

<FIG> includes perspective views of the electronic device <NUM> according to an embodiment. Referring to <FIG>, the electronic device <NUM> includes a pair of housings <NUM> and <NUM>', and rolls <NUM> and <NUM>' are provided in the housings <NUM> and <NUM>', respectively. An end of the flexible display <NUM> is fixed to the roll <NUM> and the other end thereof is fixed to the roll <NUM>'. The flexible display <NUM> is wound on the rolls <NUM> and <NUM>' and accommodated in the housings <NUM> and <NUM>'. Openings <NUM> and <NUM>' through which the flexible display <NUM> enters and exits are provided in the housings <NUM> and <NUM>', respectively. The housings <NUM> and <NUM>' are positioned in such a manner that the openings <NUM> and <NUM>' face each other. Roll guides <NUM> and <NUM>' for guiding the rolls <NUM> and <NUM>' are provided in the housings <NUM> and <NUM>', respectively. Due to the above-described configuration, the flexible display <NUM> may extend out of/retract into the housings <NUM> and <NUM>' by pulling/pushing the housings <NUM> and <NUM>' away from/toward each other.

<FIG> shows that the flexible display <NUM> is accommodated in the housings <NUM> and <NUM>'. The housings <NUM> and <NUM>' closely contact each other. In this state, when the housings <NUM> and <NUM>' are pulled away from each other, as illustrated in <FIG>, the flexible display <NUM> is unwound from the rolls <NUM> and <NUM>', extends through the openings <NUM> and <NUM>', and is spread between the housings <NUM> and <NUM>'. When the housings <NUM> and <NUM>' are pulled away from each other by the maximum distance, as illustrated in <FIG>, the flexible display <NUM> is completely unwound from the rolls <NUM> and <NUM>' and spread between the housings <NUM> and <NUM>', thereby ensuring the widest image display area.

The roll guides <NUM> and <NUM>' extend in a vertical direction. The rolls <NUM> and <NUM>' move downward along the roll guides <NUM> and <NUM>' as the flexible display <NUM> is unwound from the rolls <NUM> and <NUM>', and are positioned at lower ends of the roll guides <NUM> and <NUM>' when the flexible display <NUM> is completely spread. When the housings <NUM> and <NUM>' are pushed toward each other, the rolls <NUM> and <NUM>' rotate in directions for winding the flexible display <NUM> thereon due to, for example, elastic force of the spiral spring <NUM>. When a wound length of the flexible display <NUM> on the rolls <NUM> and <NUM>' is increased, the rolls <NUM> and <NUM>' move upward along the roll guides <NUM> and <NUM>'. Therefore, even when the wound length of the flexible display <NUM> on the rolls <NUM> and <NUM>' varies, proceeding directions of the flexible display <NUM> with respect to the openings <NUM> and <NUM>' in the housings <NUM> and <NUM>' may be constantly maintained.

Claim 1:
An electronic device comprising:
a housing (<NUM>) comprising a first portion having an opening (<NUM>), a second portion opposite to the first portion, a third portion connecting the first portion and the second portion, and a fourth portion opposite to the third portion;
a roll (<NUM>) mounted in the housing (<NUM>);
a flexible display (<NUM>) wound on the roll (<NUM>) and being extendable and retractable through the opening (<NUM>) based on a rotation direction of the roll (<NUM>);
a roll guide (<NUM>) configured to guide the roll (<NUM>) to move in a direction capable of maintaining a proceeding direction of the flexible display (<NUM>) toward the opening (<NUM>) in the housing (<NUM>), based on a variation in a wound length of the flexible display (<NUM>) on the roll (<NUM>);
a display guide (<NUM>) having a supporting surface (<NUM>, <NUM>) configured to support the flexible display (<NUM>) wound on the roll (<NUM>), and to guide the flexible display (<NUM>) when the flexible display (<NUM>) is unwound from the roll (<NUM>), toward the opening (<NUM>) in the housing (<NUM>),
a guide member (<NUM>) disposed inside the housing on an inner surface of the first portion and comprising a curvature surface configured to guide the flexible display to proceed in a direction perpendicular to the inner surface of the first portion; and
a push member (<NUM>) configured to push the roll (<NUM>) toward the display guide (<NUM>) such that the flexible display (<NUM>) wound on the roll (<NUM>) contacts the supporting surface (<NUM>, <NUM>).