Patent Description:
The present disclosure relates to a display device, and more particularly, to a rollable display device which is capable of displaying images even in a rolled state.

As display devices which are used for a monitor of a computer, a television, a cellular phone, or the like, there are an organic light emitting display (OLED) apparatus which is a self-emitting apparatus, a liquid crystal display (LCD) apparatus which requires a separate light source, and the like.

An applicable range of the display device is diversified to personal digital assistants as well as monitors of computers and televisions and a display device with a large display area and a reduced volume and weight is being studied.

Further, recently, a rollable display device which is manufactured by forming a display element, a wiring line, and the like on a flexible substrate such as plastic which is a flexible material so as to be capable of displaying images even in the rolled state of the display device is getting attention as a next generation display device.

<CIT> discloses a rollable display and a driving method thereof, and a screen of a flexible display panel is separated into an exposed display region and a non-exposed display region. The display moves the screen of the flexible display panel using a screen driver, and controls a moving direction of the exposed display region to be opposite to a moving direction of the screen.

<CIT> discloses a flexible display apparatus which has a small thickness and makes it easy to wind or unwind a flexible display module.

<CIT> presents a rollable display device that includes a roller having a cylindrical shape and an outer circumferential surface on which a display panel is rolled. A cylinder member supports rotation of the roller, using a rotation support member coupled thereto. A housing member is rotatable together with the roller. A torsional elastic member is fixed to the cylinder member and the housing member. A housing inner member is provided on an inner circumferential surface of the housing member.

<CIT> presents a display device including a first rotation member configured to rotate, a second rotation member configured to rotate, the second rotation member being spaced apart from the first rotation member, a conveyance member extending between the first and the second rotation member, is configured to be conveyed between the first rotation member and the second rotation member in accordance with respective rotations of the first rotation member and the second rotation member, and has an inner surface and an outer surface, an abutting movement member that is disposed between the first rotation member and the second rotation member, and is configured to move to cause the conveyance member to be partially pushed up while being abutted against the inner surface, and a display member having flexibility that is attached to the outer surface, and displays an image using an organic light emitting phenomenon.

An object to be achieved by the present disclosure is to provide a rollable display device which is capable of providing a partial view without causing burn-in.

Objects of the present disclosure are not limited to the above-mentioned objects, and other objects, which are not mentioned above, can be clearly understood by those skilled in the art from the following descriptions.

The object is achieved by the invention as defined by the features of the independent claim.

The invention as mentioned above can be further equipped or embodied with one or more of the following features.

In one or more embodiments, the display device comprises an extending sheet which is fastened with an upper end of the back cover.

A lower end of the back cover is fastened with the first roller.

The display device comprises a housing unit which accommodates the first roller.

In one or more embodiments, the opening may include a second opening through which the extending sheet moves in the vertical direction.

An upper end of the extending sheet or extending cover may be fastened with the third roller.

In one or more embodiments, the display device may further comprise a first rotary shaft which may be axially coupled to the first roller.

In one or more embodiments, the display device may further comprise a roller support unit which may be provided on both sides of the first roller and is rotatably coupled to the first rotary shaft.

In one or more embodiments, the display device may further comprise a torsion spring which may be wound around the first rotary shaft to be installed in the first roller.

The display device comprise a second rotary shaft which is axially coupled to the second roller.

The display device comprises a fastening unit which is connected to an end of the second rotary shaft.

In one or more embodiments, the display device may further comprise a torsion spring which is wound around the second rotary shaft to be installed in the second roller.

In one or more embodiments, the display device may further comprise a first motor which is disposed at one side of the first roller and lifts and lowers the back cover and the display panel; and a second motor which rotates the third roller.

In one or more embodiments, after lifting the back cover and the display panel by driving the first motor and winding the extending sheet around the third roller by driving the second motor, the first motor may be turned off to constantly maintain a height of a watching area (a display area in which a screen is driven in the display area) to display images.

In one or more embodiments, in a state in which the first motor is turned off, the second motor may be driven and/or the third roller may be rolled to move the watching area.

In one or more embodiments, the extending sheet may be wound around the third roller to locate an upper end of the display area to be close to the third roller and the first motor may be turned off and the watching area may be driven on a front surface and a rear surface of the display device to display images.

Other detailed matters of the exemplary embodiments are included in the detailed description and the drawings.

According to the present disclosure, a plurality of rollers is applied to flexibly adjust an emission area during the partial view. Therefore, the burn-in phenomenon is suppressed to improve the lifespan.

Advantages and characteristics of the present disclosure and a method of achieving the advantages and characteristics will be clear by referring to exemplary embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the exemplary embodiments disclosed herein but will be implemented in various forms. The exemplary embodiments are provided by way of example only so that those skilled in the art can fully understand the disclosures of the present disclosure and the scope of the present disclosure. Therefore, the present disclosure will be defined only by the scope of the appended claims.

The shapes, sizes, ratios, angles, numbers, and the like illustrated in the accompanying drawings for describing the exemplary embodiments of the present disclosure are merely examples, and the present disclosure is not limited thereto. Further, in the following description of the present disclosure, a detailed explanation of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure. The terms such as "including," "having," and "consist of" used herein are generally intended to allow other components to be added unless the terms are used with the term "only". Any references to singular may include plural unless expressly stated otherwise.

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to accompanying drawings.

A rollable display device may also be referred to as a display device which is capable of displaying images even though the display device is rolled. The rollable display device may have a high flexibility as compared with a general display device of the related art. Depending on whether to use a rollable display device, a shape of the rollable display device may freely vary. Specifically, when the rollable display device is not used, the rollable display device is rolled to be stored with a reduced volume. In contrast, when the rollable display device is used, the rolled rollable display device is unrolled to be used.

Referring to <FIG> and <FIG>, a display device <NUM> according to a first embodiment includes a display unit DP and a housing unit HP.

The display unit DP is a configuration for displaying images to a user. For example, in the display unit DP, a display element and a circuit and/or a wiring line and/or a component, and the like for driving the display element may be disposed.

Since the display device <NUM> of the first embodiment is a rollable display device <NUM>, the display unit DP may be configured to be wound and unwound. For example, the display unit DP of the first embodiment is formed of a display panel <NUM> and a back cover <NUM> each having a flexibility to be wound or unwound. The display unit DP will be described below in more detail with reference to <FIG> and <FIG>.

In the meantime, the display device <NUM> of the first embodiment may perform a partial view that only a partial area of the display panel <NUM> emits light to be utilized as a display area. Thus, only a portion of the display panel <NUM> is used as a display area to display images.

To this end, the display device <NUM> of the first embodiment includes a second roller 151b and a third roller (not illustrated) in addition to a main roller, that is, a first roller (not illustrated).

Further, an extending sheet <NUM> extending from the display unit DP is provided on a rear surface of the display unit DP to be fastened with the third roller.

The housing unit HP is a case in which the display unit DP is accommodated.

Specifically, the display unit DP, the extending sheet <NUM>, and the second roller 151b are accommodated in the housing unit HP in a wound state. The housing unit HP has an opening HPO through which the display unit DP, the extending sheet <NUM>, and the second roller 151b move to the inside and the outside of the housing unit HP when winding or unwinding the display unit DP. The display unit DP, the extending sheet <NUM>, and the second roller 151b may move in a vertical direction through the opening HPO of the housing unit HP.

At this time, according to the first embodiment, one opening HPO is provided, but is not limited thereto so that two openings are provided to move the display unit DP and the extending sheet <NUM> in the vertical direction, respectively.

The display unit DP of the display device <NUM> may be switched or transferred from a fully unwound state to a fully wound state or from a fully wound state to a fully unwound state.

<FIG> illustrates the display unit DP of the display device <NUM> which is fully unwound as an example.

In the fully unwound state, the display unit DP of the display device <NUM> is disposed at the outside of the housing unit HP. That is, in order for a user to watch images through the display device <NUM>, when the display unit DP is unwound to be disposed at the outside of the housing unit HP as much as possible and cannot be further unwound, it may be defined as a fully unwound state.

<FIG> illustrates the display unit DP of the display device <NUM> which is fully wound as an example.

In the fully wound state, the display unit DP of the display device <NUM> is accommodated in the housing unit HP and cannot be further wound. That is, when the user does not watch the images through the display device <NUM>, it is advantageous from the viewpoint of an outer appearance that the display unit DP, the extending sheet <NUM>, and the second roller 151b are not disposed or exposed at the outside of the housing unit HP. Therefore, the fully wound state is defined as when the display unit DP, the extending sheet <NUM>, and the second roller 151b are accommodated in the housing unit HP. However, it is not limited thereto, so that when two openings are provided, the second roller 151b may be disposed at the outside of the housing unit HP.

In order to switch the display unit DP to a fully unwound state or a fully wound state, a driving unit which winds or unwinds the display unit DP may be disposed.

<FIG> are schematic cross-sectional views for explaining a first roller 151a, a second roller 151b, and a third roller 151c in the display device <NUM> of the first embodiment. However, the present disclosure is not limited to the structure illustrated in <FIG>.

For the convenience of description, in <FIG>, a configuration of the driving unit is omitted and in <FIG>, the extending sheet <NUM> and the third roller 151c are omitted to show the configuration of the driving unit.

Referring to <FIG>, the display unit DP includes a back cover <NUM>, a display panel <NUM>, a flexible film <NUM>, and a printed circuit board <NUM>.

The display unit DP may further include a cover unit <NUM> which covers and protects the printed circuit board <NUM>.

The driving unit for driving the display unit DP may be configured to include a roller unit <NUM> and a lifting unit <NUM>.

The roller unit <NUM> may include a first roller 151a, a roller support unit <NUM>, and a first rotary shaft <NUM>.

The roller unit <NUM> may rotate the first roller 151a in a first direction DR1 or a second direction DR2 and may wind or unwind the display unit DP fixed to the roller unit <NUM>.

The roller unit <NUM> may be provided in the housing unit HP.

The first roller 151a may include a source printed circuit board <NUM> therein, but is not limited thereto.

The first roller 151a is a member around which the display unit DP is wound. The first roller 151a may be, for example, formed to have a cylindrical shape. Specifically, referring to <FIG>, the first roller 151a of the present disclosure has a D-cut shape in which a part of a cylindrical shape has a flat shape, but is not limited thereto.

A lower edge of the display unit DP may be fixed to the first roller 151a. For example, a screw passes through the second fastening hole AH2 so that the lower edge of the back cover <NUM> may be fastened with the first roller 151a, but is not limited thereto.

When the first roller 151a rotates in a first direction DR1, that is, a counterclockwise direction, the display unit DP fixed to the first roller 151a through the lower edge may be wound around the first roller 151a. In contrast, when the first roller 151a rotates in a second direction DR2 which is an opposite direction, that is, a clockwise direction, the display unit DP wound around the first roller 151a may be unwound from the first roller 151a. The first roller 151a may be formed of a metal material or a plastic material having a rigidity.

The driving unit according to the first exemplary embodiment of the present disclosure may further include a second roller 151b and a third roller 151c.

When only one first roller 151a is provided in the housing unit HP, if a partial view function is utilized, a specific part of the display panel <NUM>, that is, only an end of the display panel <NUM> may be used for the partial view. In this case, the partial view area emits relatively lighter, as compared with the remaining part of the display panel <NUM>, so that a burn-in issue may be caused.

Therefore, in the first exemplary embodiment of the present disclosure, in addition to the first roller 151a, the second roller 151b is provided at the outside of the housing unit HP, and the third roller 151c is provided in the housing unit HP. That is, according to the first exemplary embodiment of the present disclosure, in order to drive the display unit DP, three rollers including the first roller 151a, the second roller 151b, and the third roller 151c, two motors including a first motor <NUM> and a second motor <NUM>, and one torsion spring <NUM> may be provided.

The position of the emission area of the display panel <NUM> may be flexibly adjusted by the vertical movement of the second roller 151b and the rolling of the third roller 151c so that the partial view is possible without causing the burn-in issue.

The display unit DP and/or the extending sheet <NUM> are overlaid on the second roller 151b and an end of the extending sheet <NUM> may be fastened with the third roller 151c.

The third roller 151c is connected to the second motor <NUM> to be rotatably driven, but is not limited thereto. For the simplification of the driving or the equipment, the third roller 151c may use a spring instead of the second motor <NUM>.

As described above, the position of the emission area of the display panel <NUM> may be adjusted in accordance with a rotation state of the first roller 151a, a lifted height of the second roller 151b, and a rotation state of the third roller 151c.

Specifically, referring to <FIG> together, the roller support unit <NUM> may support the first roller 151a on both sides of the first roller 151a.

Specifically, the roller support unit <NUM> may be disposed on a bottom surface HPF of the housing unit HP. Upper side surfaces of the roller support unit <NUM> may be coupled to both ends of the first roller 151a. Therefore, the roller support unit <NUM> allows the first roller 151a to be rotatably coupled to the roller support unit <NUM> to be spaced apart from the bottom surface HPF of the housing unit HP. Therefore, the first roller 151a may rotate around the first rotary shaft <NUM> in the first direction DR1 or the second direction DR2. The rolling of the first roller 151a may be performed by a torsion spring <NUM> installed in the first roller 151a.

The torsion spring <NUM> is wound around the first rotary shaft <NUM> to be installed in the first roller 151a, but is not limited thereto. The torsion spring <NUM> pulls the display unit DP downwardly at all times and upwardly pushes the display unit DP by the driving of the first motor <NUM>.

That is, the driving unit further includes a first motor <NUM> and a driving shaft <NUM>.

The first motor <NUM> may include a gear box, but is not limited thereto.

The driving force of the first motor <NUM> may be transmitted to the lifting unit <NUM> by means of the driving shaft <NUM>. A plurality of links <NUM> of the lifting unit <NUM> is upwardly unfolded by the driving of the first motor <NUM> to push up the second roller 151b fastened with the roller lifting unit <NUM> and thus, the display unit DP may be upwardly driven.

That is, the lifting unit <NUM> moves the display unit DP in a vertical direction in accordance with the driving of the roller unit <NUM>. The lifting unit <NUM> includes a plurality of links <NUM> which is hinged to each other and a roller lifting unit <NUM> fixed to an end of the link <NUM>. Each of the plurality of links <NUM> is rotatably hinged to each other to be lifted and lowered in the vertical direction by the driving of the first motor <NUM>. When the plurality of links <NUM> moves in the vertical direction, each of the plurality of links <NUM> may rotate to be farther from each other or closer to each other.

Referring to <FIG> together, one end of the roller lifting unit <NUM> is fixedly coupled to one end of the link <NUM> and the other end may be rotatably fastened with the fastening unit <NUM> connected to a second rotary shaft <NUM>. The roller lifting unit <NUM> and the link <NUM> may form a predetermined angle so that the link <NUM> is not seen from the front surface of the display device <NUM>, but is not limited thereto. A length of the roller lifting unit <NUM> may be set to accommodate the roller lifting unit <NUM> in the housing unit HP.

The second roller 151b is axially coupled to the second rotary shaft <NUM> and the second rotary shaft <NUM> may be rotatably fastened with the fastening unit <NUM>. The roller lifting unit <NUM> may be rotatably fastened with the fastening unit <NUM> by means of a hinge rotation bush <NUM>, but is not limited thereto. Therefore, the roller lifting unit <NUM> is lifted or lowered to lift or lower the second roller 151b fastened with the fastening unit <NUM>. By doing this, the display unit DP may be lifted or lowered.

In the meantime, referring to <FIG> together, the third roller 151c may rotate by the driving of the second motor <NUM>. The third roller 151c may be connected to the second motor <NUM> by means of gears <NUM> and <NUM> to rotate. The extending sheet <NUM> may be wound around or unwound from the third roller 151c by the rotation of the third roller 151c and thus the emission area of the display unit DP may be adjusted.

In some exemplary embodiments, a driving unit having a structure other than the above-described driving unit may be applied to the display device <NUM>. That is, as long as the display unit DP is wound and unwound, the above-described configuration of the roller unit <NUM> and the lifting unit <NUM> may be modified, some configurations may be omitted, or another configuration may be added.

Hereinafter, the display unit DP and the extending sheet <NUM> may be described in more detail with reference to <FIG> and <FIG> together.

Referring to <FIG> or <FIG>, the display unit DP may include a back cover <NUM>, <NUM>', a display panel <NUM>, a flexible film <NUM>, and a printed circuit board <NUM>.

The display panel <NUM> is a panel for displaying images to a user.

The display panel <NUM> may include a display element which displays images, a driving element which drives the display element, wiring lines which transmit various signals to the display element and the driving element, and the like. The display element may be defined in different ways depending on a type of the display panel <NUM>. For example, when the display panel <NUM> is an organic light emitting display panel, the display element may be an organic light emitting diode which includes an anode, an organic light emitting layer, and a cathode. For example, when the display panel <NUM> is a liquid crystal display panel, the display element may be a liquid crystal display element. Hereinafter, even though the display panel <NUM> is assumed as an organic light emitting display panel, the display panel <NUM> is not limited to the organic light emitting display panel.

Further, since the display device <NUM> according to the first exemplary embodiment of the present disclosure is a rollable display device, the display panel <NUM> may be implemented as a flexible display panel to be wound around or unwound from the first roller 151a.

The display panel <NUM> includes a display area AA and may include a non-display area NA.

The display area AA is an area where images are displayed in the display panel <NUM>.

In the display area AA, a plurality of sub pixels which configures the plurality of pixels and a circuit for driving the plurality of sub pixels may be disposed. The plurality of sub pixels is minimum units which configure the display area AA and a display element may be disposed in each of the plurality of sub pixels. The plurality of sub pixels may configure a pixel. For example, an organic light emitting diode which includes an anode, an organic light emitting layer, and a cathode may be disposed in each of the plurality of sub pixels, but it is not limited thereto. Further, a circuit for driving the plurality of sub pixels may include a driving element, a wiring line, and the like. For example, the circuit may be configured by a thin film transistor, a storage capacitor, a gate line, a data line, and the like, but is not limited thereto.

The non-display area NA is an area where no image is displayed.

In the non-display area NA, various wiring lines and circuits for driving the organic light emitting diode of the display area AA are disposed. For example, in the non-display area NA, a link line which transmits signals to the plurality of sub pixels and circuits of the display area AA, a driving IC such as a gate driver IC or a data driver IC, or the like may be disposed, but it is not limited thereto.

The flexible film <NUM> is a film in which various components are disposed on a base film having a malleability. Specifically, the flexible film <NUM> is a film which supplies a signal to the plurality of sub pixels and the circuits of the display area AA and is electrically connected to the display panel <NUM>. The flexible film <NUM> is disposed at one end of the non-display area NA of the display panel <NUM> to supply a power voltage, a data voltage, or the like to the plurality of sub pixels and the circuits of the display area AA. Even though four flexible films <NUM> are illustrated in <FIG> and <FIG>, the number of flexible films <NUM> may vary depending on the design and is not limited thereto.

In the meantime, for example, a driving IC such as a gate driver IC or a data driver IC may be disposed on the flexible film <NUM>. The driving IC is a component which processes data for displaying images and a driving signal for processing the data. The driving IC may be disposed by a chip on glass (COG), a chip on film (COF), a tape carrier package (TCP), or the like depending on a mounting method. However, for the convenience of description, it is described that the driving IC is mounted on the flexible film <NUM> by a chip on film manner, but is not limited thereto.

The printed circuit board <NUM> is disposed at one end of the flexible film <NUM> to be connected to the flexible film <NUM>. The printed circuit board <NUM> is a component which supplies signals to the driving IC. The printed circuit board <NUM> may supply various signals such as a driving signal or a data signal to the driving IC. For example, a data driver which generates data signals may be mounted in the printed circuit board <NUM> and the generated data signal may be supplied to the plurality of sub pixels and the circuit of the display panel <NUM> through the flexible film <NUM>. Even though one printed circuit board <NUM> is illustrated in <FIG> and <FIG>, the number of printed circuit boards <NUM> may vary depending on the design and is not limited thereto.

The back cover <NUM>, <NUM>' is disposed on rear surfaces of the display panel <NUM>, the flexible film <NUM>, and the printed circuit board <NUM> to support the display panel <NUM>, the flexible film <NUM>, and the printed circuit board <NUM>. Therefore, a size of the back cover <NUM>, <NUM>' may be larger than a size of the display panel <NUM>. Therefore, the back cover <NUM>, <NUM>' may protect other configurations of the display unit DP from the outside. Even though the back cover <NUM>, <NUM>' is formed of a material having a rigidity, at least a part of the back cover <NUM>, <NUM>' may have a flexibility to be wound or unwound together with the display panel <NUM>. For example, the back cover <NUM>, <NUM>' may be formed of a metal material such as steel use stainless SUS or invar, plastic, or the like. However, as long as a material of the back cover <NUM>, <NUM>' satisfies physical conditions such as a thermal strain, a radius of curvature, and a rigidity, various materials may be used, and is not limited thereto.

In the meantime, the back cover <NUM>, <NUM>' may include a plurality of openings <NUM>.

The plurality of openings <NUM> may allow the back cover <NUM>, <NUM>' to have a flexibility. The plurality of openings <NUM> may be flexibly deformed and allow the back cover <NUM>, <NUM>' to be wound around the first roller 151a or unwound from the first roller 151a together with the display panel <NUM>.

The back cover <NUM>, <NUM>' may include a plurality of support areas PA and a plurality of malleable areas MA. The plurality of support areas PA is areas where a plurality of openings <NUM> is not disposed and the plurality of malleable areas MA is areas where a plurality of openings <NUM> is disposed. For example, referring to <FIG>, in the back cover <NUM>, a first support area PA1, a first malleable area MA1, a third support area PA3, a second malleable area MA2, and a second support area PA2 are sequentially disposed from the uppermost end of the back cover <NUM>. However, the present disclosure is not limited thereto and referring to <FIG>, in the back cover <NUM>', the first support area PA1, the first malleable area MA1, and the third support area PA3 may be sequentially disposed from the uppermost end of the back cover <NUM>'. Hereinafter, the back cover <NUM> of <FIG> will be mainly described, but the same configuration may be applied to the back cover <NUM>' of <FIG> in the same manner.

The first support area PA1 of the back cover <NUM> is an uppermost area of the back cover <NUM> and is fastened with the extending sheet <NUM>. A first fastening hole AH1 may be formed in the first support area PA1 to be fastened with the extending sheet <NUM> and a fourth fastening hole AH4 may be formed in the corresponding extending sheet <NUM>. For example, the display unit DP and the extending sheet <NUM> may be fastened with each other by means of a fixing member which passes through the first fastening hole AH1 and the fourth fastening hole AH4. However, it is not limited thereto and as illustrated in <FIG>, the display unit DP and the extending sheet <NUM> may be fastened by means of the other configuration, such as an adhesive layer or an adhesive tape.

Further, the first malleable area MA1 is an area extending from the first support area PA1 to a lower side of the back cover <NUM>. The first malleable area MA1 is an area in which a plurality of openings <NUM> is disposed and the display panel <NUM> is attached.

The third support area PA3 is an area extending from the first malleable area MA1 to the lower side of the back cover <NUM>. A flexible film <NUM> which is connected to one end of the display panel <NUM> and a printed circuit board <NUM> may be disposed in the third support area PA3.

In order to protect the flexible film <NUM> and the printed circuit board <NUM>, the third support area PA3 may support the flexible film <NUM> and the printed circuit board <NUM> to be wound around the first roller 151a in a flat shape, rather than a curved shape. A part of the first roller 151a may be formed to be flat, corresponding to the third support area PA3, but is not limited thereto.

The second malleable area MA2 is an area extending from the third support area PA3 to a lower side of the back cover <NUM>. A plurality of openings <NUM> may be disposed in the second malleable area MA2.

The second malleable area MA2 extends to dispose the display area AA of the display panel <NUM> at the outside of the housing unit HP. For example, when the back cover <NUM> and the display panel <NUM> are fully unwound, the second support area PA2 of the back cover <NUM> which is fixed to the first roller 151a to the third support area PA3 may be disposed in the housing unit HP. The first malleable area MA1 and the first support area PA1 to which the display panel <NUM> is attached may be disposed at the outside of the housing unit HP.

The second support area PA2 of the back cover <NUM> is a lowermost area of the back cover <NUM> and may be fastened with the first roller 151a. The second support area PA2 may include second fastening holes AH2 to be fastened with the first roller 151a. For example, the first roller 151a and the second support area PA2 of the back cover <NUM> may be fastened with each other by a screw which passes through the first roller 151a and the second fastening holes AH2. As the second support area PA2 is fastened with the first roller 151a, the back cover <NUM> may be wound around or unwound from the first roller 151a by the rotation of the first roller 151a. However, the present disclosure is not limited thereto, and referring to <FIG>, the fourth fastening hole AH4 may be formed at a lower end of the extending sheet <NUM>' to be fastened with the first roller 151a. For example, the first roller 151a and the extending sheet <NUM>' may be fastened with each other by a screw which passes through the first roller 151a and the fourth fastening hole AH4.

In the meantime, the extending sheet <NUM>, <NUM>' of the present disclosure may be disposed above the display unit DP or on a rear surface of the back cover <NUM>.

Referring to <FIG>, the extending sheet <NUM> may be connected to an upper end of the display unit DP.

That is, as described above, at least one fourth fastening hole AH4 may be disposed at a lower end of the extending sheet <NUM>. The back cover <NUM> and the extending sheet <NUM> may be fastened with each other by a screw which passes through the first fastening hole AH1 and the fourth fastening hole AH4.

At least one fifth fastening hole AH5 may be formed at an upper end of the extending sheet <NUM>. For example, the third roller 151c and the extending sheet <NUM> may be fastened with each other by a screw which passes through the third roller 151c and the fifth fastening hole AH5.

The extending sheet <NUM> may be configured by a plastic material such as polyethylene terephthalate (PET), but is not limited thereto.

In contrast, referring to <FIG>, the back cover <NUM>' may be attached onto the extending sheet <NUM>'. In this case, the back cover <NUM>' may not include the second malleable area and the second support area and in the first support area PA1 of the back cover <NUM>', the first fastening hole may not be provided, but is not limited thereto.

The extending sheet <NUM>' covers the display unit DP and may extend to the upper portion and the lower portion.

At least one fifth fastening hole AH5 may be formed at an upper end of the extending sheet <NUM>'. For example, the third roller 151c and the extending sheet <NUM>' may be fastened with each other by a screw which passes through the third roller 151c and the fifth fastening hole AH5.

The extending sheet <NUM>' may be configured by a plastic material such as polyethylene terephthalate PET, but is not limited thereto.

Hereinafter, a display method of the display device configured as described above such as a full view or a partial view may be described in more detail.

The reference symbol "A" illustrated in <FIG> and <FIG> denotes an upper end of the display area of the display panel. In a screen ON illustrated in <FIG> and <FIG>, a signal is applied to the display panel to display images and in a screen OFF, a signal is not applied to the corresponding display panel so that the image is not displayed.

<FIG> illustrates a basic type of a partial view as an example and <FIG> illustrates a modified shape of a partial view in which a watching area moves. Here, the watching area refers to a display area of the screen ON.

Referring to <FIG>, in the display device according to the first embodiment, the first motor may lift the display unit DP and the second motor <NUM> may roll the extending sheet <NUM>.

The first motor and the second motor <NUM> are controlled to lift and lower the display unit DP and change the watching area.

The first motor <NUM> is driven to lift the lifting unit and the second motor <NUM> is driven to wind the extending sheets <NUM> around the third roller 151c to lift and lower the display unit DP.

At this time, when the first motor <NUM> is turned off, a total height of the watching area is constantly maintained and the corresponding display area is driven (ON) to watch the image.

In the meantime, referring to <FIG>, when the second motor <NUM> is driven in this state, the watching area may be changed. That is, the second motor <NUM> is driven to roll the third roller 151c, so that the extending sheet <NUM> is wound around or unwound from the third roller 151c and thus the watching area may be moved and the emission area may be flexibly adjusted. Therefore, the burn-in phenomenon is suppressed to improve the lifespan.

In the meantime, according to the present disclosure, the image may be watched not only on the front surface of the display device, but also on the rear surface of the display device, which will be described in more detail with reference to the drawing.

The only difference between a display device of <FIG> and the display device of <FIG> and <FIG> is the driving of the display area, but the other configurations are substantially the same so that a redundant description will be omitted. The same configuration will be denoted with the same reference numeral.

A referential symbol A illustrated in <FIG> denotes an upper end of the display area of the display panel. Further, the screen ON illustrated in <FIG> indicates that a signal is applied to a corresponding display panel to display images.

Referring to <FIG>, the first motor <NUM> is driven to lift the lifting unit and the second motor <NUM> is driven to wind the extending sheets <NUM> around the third roller 151c to lift and lower the display unit DP.

In this case, the extending sheet <NUM> is sufficiently wound around the third roller 151c so that the upper end A of the display area may be located to be close to the third roller 151c.

When the first motor <NUM> is turned off, a total height of the watching area is constantly maintained and the corresponding display area is driven (ON) to watch the image. Therefore, the display area is located not only on the front surface of the display device, but also on the rear surface so that both display areas are driven (ON) to simultaneously watch the images on both sides.

At this time, a total height of the watching area may be adjusted by driving the first motor.

The only difference between a display device of <FIG> and <FIG> and the display device of <FIG> and <FIG> is a total height of the watching area, but the other configurations are substantially the same so that a redundant description will be omitted. The same configuration will be denoted with the same reference numeral.

Referential symbols A and B illustrated in <FIG> and <FIG> denote an upper end and a lower end of the display area of the display panel, respectively.

Referring to <FIG>, as illustrated in <FIG>, the first motor <NUM> is driven to lift the lifting unit and the second motor <NUM> is driven to wind the extending sheets <NUM> around the third roller 151c to lift and lower the display unit DP.

At this time, the display unit DP is lifted to the maximum to expose the entire display area (from A to B in <FIG>).

In this state, when the first motor <NUM> is turned off, a total height of the watching area is constantly maintained and the corresponding display area is driven (ON) to watch the image in the entire display area. For example, an area from the upper end A to the lower end B of the display area is an actual watching area and has an aspect ratio of <NUM> : <NUM>.

In the meantime, referring to <FIG>, the first motor <NUM> and the second motor <NUM> are driven to change the height of the second roller 151b and the watching area. That is, the first motor <NUM> is driven to lower the height of the second roller 151b and the second motor <NUM> is driven to roll the third roller 151c so that the extending sheet <NUM> is wound around the third roller 151c to adjust the entire display area to serve as an actual watching area. Therefore, an unnecessary area is screen-off to improve the lifespan.

According to the first exemplary embodiment of the present disclosure, the housing unit includes one opening, but is not limited thereto so that two openings are provided to move the display unit and the extending sheet in the vertical direction, respectively, which will be described in more detail with reference to a second embodiment.

The only difference between a display device <NUM> according to a second embodiment of <FIG>, <FIG>, <FIG> and the display device <NUM> of <FIG>, <FIG>, <FIG> is a configuration of openings HPO1 and HPO2 of the housing unit HP. However, the other configurations are substantially the same, so that a redundant description will be omitted. The same configuration will be denoted with the same reference numeral.

Referring to <FIG>, <FIG>, <FIG>, a display device <NUM> according to a second embodiment includes a display unit DP and a housing unit HP.

The display device <NUM> of the second embodiment includes a second roller 151b and a third roller 151c in addition to a main roller, that is, a first roller 151a. However, it is not limited thereto and the display device may not include the third roller 151c.

At this time, the display device <NUM> according to the second embodiment includes two openings HPO1 and HPO2 so that the display unit DP and the extending sheet <NUM> move in vertical direction, respectively.

That is, the openings HPO1 and HPO2 of the second embodiment include a first opening HPO1 through which the display unit DP moves in the vertical direction and a second opening HPO2 through which the extending sheet <NUM> moves in the vertical direction.

In this case, as illustrated in <FIG>, the extending sheet <NUM> and a part of the driving unit including the second roller 151b may be located at the outside of the housing unit HP. Further, according to the second embodiment, the movement of the display unit DP and the extending sheet <NUM> is guided by means of the first opening HPO1 and the second opening HPO2 so that the driving may be more smoothly performed.

In the meantime, in the first and second embodiments, three rollers are provided.

<FIG> and <FIG> are cross-sectional views illustrating an example of a partial view in a display device of an example not included in the scope of the present invention.

The only difference between a display device <NUM> of <FIG> and <FIG> and the display device <NUM> of <FIG> and <FIG> and <FIG> is the configuration of rollers 351a and 351b, but the other configurations are substantially the same so that a redundant description will be omitted. The same configuration will be denoted with the same reference numeral.

<FIG> are schematic cross-sectional views for explaining a first roller 351a and a second roller 315b in the display device <NUM> according to the example. However, the present disclosure is not limited to the structure illustrated in <FIG>.

Further, for convenience of description, a configuration of the driving unit is omitted in <FIG>.

Referring to <FIG> and <FIG>, a display device <NUM> according to the example may include a display unit DP and a housing unit HP.

The display unit DP is a configuration to display images to the user and may be formed of a display panel <NUM> and a back cover <NUM> each having a flexibility to be wound or unwound.

The display unit DP may include a back cover <NUM>, a display panel <NUM>, a flexible film <NUM>, and a printed circuit board <NUM>.

In the meantime, the display device <NUM> according to the example may perform a partial view that only a partial area of the display panel <NUM> emits light to be utilized as a display area.

To this end, the display device <NUM> according to the example includes a second roller 351b in addition to a main roller, that is, a first roller 351a.

The housing unit HP may have an opening HPO through which the display unit DP and the second roller 351b move to the inside and the outside of the housing unit HP.

As described above, the display unit DP may include a back cover <NUM>, a display panel <NUM>, a flexible film <NUM>, and a printed circuit board <NUM>.

Further, the driving unit for driving the display unit DP may be configured to include a roller unit <NUM> and a lifting unit <NUM>.

The roller unit <NUM> may include a first roller 351a, a roller support unit <NUM>, and a first rotary shaft <NUM>.

The first roller 351a may include a source printed circuit board <NUM> therein, but is not limited thereto.

The first roller 351a is a member around which the display unit DP is wound. The first roller 351a may be, for example, formed to have a cylindrical shape. Specifically, referring to <FIG>, the first roller 351a of the present disclosure has a D-cut shape in which a part of a cylindrical shape has a flat shape, but is not limited thereto.

The lower edge of the back cover <NUM> may be fixed to the first roller 351a. For example, a screw passes through the second fastening hole AH2 so that the lower edge of the back cover <NUM> may be fastened with the first roller 351a, but is not limited thereto.

The roller support unit <NUM> may support the first roller 351a at both sides of the first roller 351a. Specifically, the roller support unit <NUM> may be disposed on a bottom surface HPF of the housing unit HP. Upper side surfaces of the roller support unit <NUM> may be coupled to both ends of the first roller 351a. The first roller 351a may be rotatably coupled to the roller support unit <NUM>. Therefore, the first roller 351a may rotate around the first rotary shaft <NUM> in the first direction DR1 or the second direction DR2.

The first roller 351a may be rotated by the driving of the second motor <NUM>. The first roller 351a is connected to the second motor <NUM> by means of a gear (not illustrated) to rotate, but is not limited thereto. The display unit DP may be wound or unwound by the rotation of the first roller 351a.

At this time, when the first roller 351a rotates in a first direction DR1, that is, a counterclockwise direction, the back cover <NUM> fixed to the first roller 351a through the lower edge may be wound around the first roller 351a. In contrast, when the first roller 351a rotates in a second direction DR2 which is an opposite direction, that is, a clockwise direction, the back cover <NUM> wound around the first roller 351a may be unwound from the first roller 351a.

The driving unit of the example may further include a second roller 351b.

The example includes a second roller 351b at the outside of the housing unit HP, in addition to the first roller 351a. That is, according to the example, in order to drive the display unit DP, two rollers including the first roller 351a and the second roller 351b, two motors including a first motor <NUM> and a second motor <NUM>, and one torsion spring <NUM> installed in the second roller 351b may be provided.

The position of the emission area of the display panel <NUM> may be flexibly adjusted by the vertical movement of the second roller 351b and the rolling of the display unit DP by the torsion spring <NUM> so that the partial view is possible without causing the burn-in issue.

The display unit DP may be wound around the second roller 351b.

As described above, the position of the emission area of the display panel <NUM> may be adjusted in accordance with a rotation state of the first roller 351a and a lifted height of the second roller 351b.

The driving unit may further include the first motor <NUM> and a driving shaft <NUM>.

The driving of the first motor <NUM> may be transmitted to the lifting unit <NUM> by means of the driving shaft <NUM>. A plurality of links <NUM> of the lifting unit <NUM> is upwardly unfolded by the driving of the first motor <NUM> to push up the second roller 351b fastened with the roller lifting unit <NUM> and thus, the display unit DP may be upwardly driven. A specific configuration of the lifting unit <NUM> is substantially the same as the first embodiment described above.

One end of the roller lifting unit <NUM> is hinged with one end of the link <NUM> and the other end may be rotatably fastened with the fastening unit <NUM> connected to a second rotary shaft <NUM>. The second roller 351b is axially coupled to the second rotary shaft <NUM> and the second rotary shaft <NUM> may be fastened with the fastening unit <NUM>. The roller lifting unit <NUM> may be rotatably fastened with the fastening unit <NUM> by means of a hinge rotation bush <NUM>, but is not limited thereto. Therefore, the roller lifting unit <NUM> is lifted or lowered to lift or lower the second roller 351b fastened with the fastening unit <NUM>. By doing this, the display unit DP may be lifted or lowered.

In the meantime, the torsion spring <NUM> may be installed in the second roller 351b to be wound around the second rotary shaft <NUM>, but is not limited thereto. The torsion spring <NUM> pulls up the display unit DP at all times so that the display unit DP may be wound around the second roller 351b.

<FIG> and <FIG> are cross-sectional views illustrating an example of a partial view in a display device according to an example not included in the scope of the present invention.

The reference symbol A illustrated in <FIG> and <FIG> denotes an upper end of the display area. A screen ON illustrated in <FIG> and <FIG> indicates that a signal is applied to a corresponding display panel to display images.

<FIG> illustrates a basic type of a partial view as an example and <FIG> illustrates a modified shape of a partial view in which a watching area moves. Here, the watching area refers to a display area in the screen ON.

Referring to <FIG>, in the display device according to the example, the display unit DP may be lifted or lowered by means of the first motor and the second motor <NUM>.

That is, the first motor and the second motor <NUM> are controlled to lift or lower the display unit DP and change the watching area.

As described above, when the first motor is driven (ON), the plurality of links of the lifting unit is upwardly unfolded to push up the second roller 351b fastened with the lifting unit and thus, the display unit DP may be upwardly driven. When the display unit DP is lifted to a predetermined height and the first motor is turned off, a total height of the watching area is constantly maintained and the corresponding display area is driven (ON) to watch the image.

Claim 1:
A display device comprising:
a display panel (<NUM>) having a display area (AA);
a back cover (<NUM>) disposed on a rear surface of the display panel (<NUM>);
a first roller (151a) which winds or unwinds the back cover (<NUM>) and the display panel (<NUM>);
a second roller (151b) disposed above the first roller (151a) to move in a vertical direction, the back cover (<NUM>) and the display panel (<NUM>) being overlaid thereon;
a rotary shaft (<NUM>) axially coupled to the second roller (151b);
a fastening unit (<NUM>) connected to an end of the rotary shaft (<NUM>);
a housing unit (HP) for accommodating the first roller (151a), wherein the housing unit (HP) includes an opening (HPO) through which the back cover (<NUM>) and the display panel (<NUM>) move to an outside and an inside of the housing unit (HP);
an extending sheet (<NUM>), wherein the extending sheet (<NUM>) is fastened with an upper end of the back cover (<NUM>) and a lower end of the back cover (<NUM>) is fastened with the first roller (151a), or wherein the extending sheet (<NUM>) is disposed on a rear surface of the back cover (<NUM>) and has a lower end fastened with the first roller (151a);
a third roller (151c) disposed in the housing unit (HP), wherein one end of the extending sheet (<NUM>) is fastened with the third roller (151c);
a first motor (<NUM>) disposed on one side of the first roller (151a);
a driving shaft (<NUM>) coupled to the first motor (<NUM>);
a second motor (<NUM>) for rotating the third roller (151c), wherein the extending sheet (<NUM>) is wound around or unwound from the third roller (151c); and
a lifting unit (<NUM>) including:
- a plurality of links (<NUM>) disposed on the rear surface of the back cover (<NUM>) and hinged with each other, and
- a roller lifting unit (<NUM>) coupled to an end of the link (<NUM>), and wherein the roller lifting unit (<NUM>) is rotatably fastened with the fastening unit (<NUM>);
wherein the first motor (<NUM>) is configured to be driven to lift the lifting unit (<NUM>) and the second motor (<NUM>) is configured to be driven to wind the extending sheets (<NUM>) around the third roller (151c) to lift and lower the display panel (<NUM>); and
wherein the plurality of links (<NUM>) is connected to the driving shaft (<NUM>) through the other end of the link (<NUM>) to be lifted and lowered in the vertical direction in accordance with driving of the first motor (<NUM>).