Adjustable display device

A display device capable of being adjusted between flat and curved comprising: a display panel; a back cover system including: at least two angle block modules, one in each half of the back cover system, the angle block modules, wherein moving the angle block modules changes a curvature of the display panel; a driving system to move the angle block modules. A driving system includes a motor; a gear connected to the motor; block units arranged in a row in the angle block module and positioned at a rear of the display panel; a shaft bearing connecting a first block unit to a second block unit. A flatness controlling unit comprises an angle block module having a flatness controlling groove; a wire guided by the flatness controlling groove; and a tension adjusting part including a portion of the wire and a spring connected to the portion of the wire.

The application claims the benefit of priority to Korean Patent Applications No. 10-2014-0051848 filed in Korea on Apr. 29, 2014 and No. 10-2014-0089831 filed in Korea on Jul. 16, 2014, which are incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND

1. Field of the Disclosure

The present disclosure relates to an adjustable or variable display device that is able to be used in a flat mode and a curved mode, and more particularly, to an adjustable or variable display device with improved flatness.

2. Discussion of the Related Art

With rapid development of information technologies, display devices for displaying a large amount of information have been recently developed. More particularly, various flat panel display (FPD) devices have been introduced.

The flat panel display devices include, for example, liquid crystal display (LCD) devices, plasma display panel (PDP) devices, field emission display (FED) devices, electroluminescence display (ELD) devices, and organic electroluminescent display (OLED) devices. The flat panel display devices generally have a thin profile, light weight, and low power consumption; and have been rapidly replacing cathode ray tubes (CRT).

Recently, curved display devices have emerged as a new generation display device because the curved display devices enable a user to be further immersed in the content, to watch realistic images, and to feel more comfortable.

In curved display devices, because a distance from the eyes of the user to a center of the screen is equal to a distance from the eyes of the user to sides of the screen, distortion of an image at the sides of the screen is minimized.

Meanwhile, variable display devices having the advantages of the flat panel display devices with wide viewing angles and curved display devices with increased immersion and comfort properties have been pursued and researched.

For the convenience of the user, the variable display devices are implemented in both a flat mode to provide wide viewing area, and in a curved mode to improve immersion while watching.

SUMMARY

An advantage of the present invention is to provide a variable display device that is able to be implemented in both a flat mode and a curved mode.

Another advantage of the present invention is to provide a variable display device that has an accurate curvature when it is implemented in a curved mode, minimizes vibrations and noises when it is changed between the flat mode and the curved mode, and has a relatively light weight and thin profile.

Another advantage of the present invention is to provide a variable display device that improves flatness when it is implemented in the flat mode.

To achieve these and other advantages and in accordance with the purpose of embodiments of the invention, as embodied and broadly described, a variable display device capable of being adjusted between flat and curved comprising: first and second angle block modules, one in each half of a rear of the device, the first and the second angle block modules capable of being moved, wherein moving the first and the second angle block modules changes a curvature of the display device; and a driving system to move the first and the second angle block modules.

A display device capable of being adjusted between flat and curved comprising: an adjusting system at a rear of the display device including: first and second angle block modules capable of being moved, wherein moving the angle block modules changes a curvature of the display device; and a driving system coupled to the angle block module, wherein the driving system moves the angle block modules.

A display device capable of being adjusted between flat and curved comprising: an angle block module at a rear of the display device capable of being moved, wherein moving the angle block module changes a curvature of the display device; and a driving system to move the angle block module.

A flatness controlling unit of a display device comprising: a driving system coupled to the display device; an angle block module coupled to the driving system having a flatness controlling groove; a wire guided by the flatness controlling groove having a first end connected to the driving system and a second end connected to the angle block module; a tension adjusting part including a portion of the wire and a spring connected to the portion of the wire.

A driving system to curve and flatten a display device comprising: a driver generating motion in a first and a second direction; a driver component connected to the driver transferring the motion to an angle block module; block units arranged in a row in the angle block module and positioned at a rear of the display device; a shaft bearing connecting a first block unit to a second block unit; wherein the motion generates movement of the block units to move a portion of the display device with respect to a direction normal to a center of the display device.

A method of adjusting a display device between flat and curved, the display device having an angle block module at a rear of the display device, the angle block module capable of being moved, and a driving system to move the angle block module, the method comprising the step of: activating the driving system to move the angle block module to adjust a curvature of the display device.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The same reference numbers may be used throughout the drawings to refer to the same or like parts.

FIG. 1AandFIG. 1Bare perspective views schematically illustrating a variable display device according to an exemplary embodiment of the present invention, andFIG. 2is a perspective view schematically illustrating a rear side of a variable display device according to an exemplary embodiment of the present invention.

InFIGS. 1A and 1BandFIG. 2, the variable display device100according to the exemplary embodiment of the present invention includes a display panel module110, an external case120, and a support130. The display panel module110displays images, and the external case120accommodates the display panel module110. The support130is connected to a lower part or a rear part of the external case120for mounting the variable display device, and is rested on a desk, fixed to a surface of a wall, or mounted by any other of many techniques and positioned for viewing.

Here, the display panel module110may include a display panel, which may be one of a liquid crystal display (LCD) device, a plasma display panel (PDP) device, a field emission display (FED) device, an electroluminescence display (ELD) device, and an organic light emitting diode (OLED) device. Beneficially, the display panel module110may include an OLED device, which is flexible and displays images without a problem even when it is curved.

Because OLED devices are self-luminescent, the OLED devices do not require a backlight unit and have a thin profile and light weight as compared with LCD devices, which are non-emissive.

In addition, the OLED devices have better viewing angles and contrast ratio than comparable LCD devices and have lower power consumption. The OLED devices are driven by low voltage of direct current (DC), and have relatively fast response time. Since the OLED devices include solid components, the OLED devices are resistant to outer impacts and are stable under temperatures within a wide range.

Also, because manufacturing processes of the OLED devices are simpler, manufacturing costs of the OLED device are further reduced as compared with an LCD device.

Here, the display panel, which is an OLED device, includes a first substrate and a second substrate facing each other. The first and second substrates are spaced apart from and attached to each other by a protection layer having an adhesive property.

More particularly, although not shown in the figures, a driving thin film transistor is formed in each pixel region on the first substrate, and a first electrode, an organic light-emitting layer, and a second electrode are sequentially formed on the first substrate. The first electrode is formed in each pixel region and connected to the driving thin film transistor. With applied voltage, the organic light-emitting layer emits light. The organic light-emitting layer may be formed in each pixel region. The second electrode may be formed all over the first substrate and covers the organic light-emitting layer.

The organic light-emitting layer may emit red, green, or blue light and may be generally formed by patterning an organic material emitting red, green, or blue light in each pixel region. Thus, red, green, and blue pixel regions are sequentially arranged.

The first and second electrodes and the organic light-emitting layer constitute a light-emitting diode. Here, the display panel module110may include the first electrode as an anode and the second electrode as a cathode.

The display panel is modularized with a backcover and may include a protective cover window to form the display panel module110. The backcover covers a rear surface and part of side surfaces of the display panel, and the front side of the backcover is opened such that an image displayed by the display panel is shown to the outside.

The cover window may be assembled at the front side of the backcover to protect the display panel.

As illustrated inFIG. 1A, when the display panel module110displaying images is driven in a flat mode, the variable display device100including the display panel module110has relatively wide viewing area and provides many viewers with the images displayed by the display panel module110.

On the other hand, as illustrated inFIG. 1B, when the display panel module110is driven in a curved mode, the variable display device100enables a viewer to be further immersed in watching, to watch realistic images and to feel more comfortable.

Namely, because the variable display device100is variably driven in the flat mode and the curved mode, a user can selectively use the variable display device100in the flat mode or curved mode as occasion demands.

The variable display device100is variably oriented in the flat mode or the curved mode by a backcover system200, which is installed at a rear surface of the display panel module110, as illustrated inFIG. 2. This will be described in more detail with reference to accompanying drawings.

FIG. 3is a view schematically illustrating a backcover system according to an exemplary embodiment of the present invention.FIG. 4is an exploded perspective view schematically illustrating an angle block module according to an exemplary embodiment of the present invention.

InFIG. 3andFIG. 4, the backcover system200is installed at a rear surface of the backcover of the display panel module110ofFIG. 2, and the backcover system200includes an angle block module210, a driving system220, and a flatness controlling unit300. The driving system220supplies power to the angle block module210. An angle block module is a mechanical structure attached to the display device and capable of being moved to adjust the curvature of the display device.

Here, a plurality of block units211are arranged in a row in the angle block module210. Each block unit211includes an angle block213and links215. The links215convert rotary motion delivered by the driving system220into rectilinear motion. A shaft bearing217ofFIG. 4is disposed between adjacent block units211. The shaft bearing217connects the links215of each block unit211and also connects the links215of adjacent block units211. The shaft bearing217raises and lowers edges of the angle blocks213contacting each other.

For example, the driving system220includes a motor221as a driver generating rotatory power and a gear223as a driver component delivering rotary motion of the motor221into the links215. However, the driving system may include other drivers or systems that may generate movement or power such as those using hydraulic, pneumatic, piston, actuator, servos, electromagnetic, and the like.

The angle block module210is disposed at each of both left and right sides with the driving system220at the center of a width of the display module110ofFIG. 2. Here, viewing the angle block module210in detail with reference toFIG. 4, the plurality of block units211aand211bare arranged in a row in the angle block module210, and each block unit211aand211bincludes the angle block213aand213band the links215aand215b, which are disposed at both sides of the angle block213aand213b.

That is, in the first block unit211a, the first angle block213ais disposed between the first links215a. The second block unit211bis disposed next to the first block unit211a, and in the second block unit211b, the second angle block213bis disposed between the couple of second links215b, which are connected to the first links215a.

In addition, the shaft bearing217is disposed between the first and second block units211aand211b, i.e., between the first and second angle blocks213aand213band is perpendicular to a length direction of the first and second links215aand215b. Ends of the first and second links215aand215bare connected to each other through the shaft bearing217.

More particularly, each of the first links215ahas a first end and a second end, and each of the second links215bhas a third end and a fourth end. The bearing holes219are formed at the first and second ends of the first links215aand the third and fourth ends of the second links215b, respectively. The shaft bearing217is inserted into the bearing holes219at the first ends of the first links215aand the third ends of the second links215bcorresponding to each other, and the first ends of the first links215aand the third ends of the second links215bare connected to each other through the shaft bearing217.

Here, the first end of each first link215ahas an outer surface on the same plane as an outer surface of a portion of the first link215aexcluding the first and second ends and has a thinner thickness than the portion of the first link215a. The third end of each second link215bhas an inner surface on the same plane as an inner surface of a portion of the second link215bexcluding the third and fourth ends and has a thinner thickness than the portion of the second link215b. The first end of the first link215aand the third end of the second link215b, which contact each other, have a structure of engaging each other.

That is, the first end of the first link215aextends from an outer side of the portion of the first link215a, and the third end of the second link215bextends from an inner side of the portion of the second link215b.

Accordingly, the first end of the first link215aand the third end of the second link215bengage each other, and the first and second link215aand215bare installed in a line with each other, so that the angle block module210may be prevented from increasing in volume.

Meanwhile, the second end of each first link215ahas an inner surface on the same plane as an inner surface of the portion of the first link215aexcluding the first and second ends and has a thinner thickness than the portion of the first link215a. The fourth end of each second link215bhas an outer surface on the same plane as an outer surface of the portion of the second link215bexcluding the third and fourth ends and has a thinner thickness than the portion of the second link215b.

Each of the first and second angle blocks213aand213bhas a substantially rectangular shape with two long sides and two short sides. The long sides have a length corresponding to the length of the first and second links215aand215b. The short sides are perpendicular to the long sides and are shorter than the long sides. A protrusion212is formed at one of the short sides of each angle block213aand213b.

The protrusion212is thinner and narrower than each angle block213aand213b. In addition, the protrusion212is formed to be inclined toward the backcover of the display panel module110ofFIG. 2with a predetermined angle from one end of the protrusion212at the first short side to the other end of the protrusion212.

Here, the short sides of the angle blocks213aand213b, where the protrusions212are formed, may be referred to as first short sides, and the short sides of the angle blocks213aand213bopposite to the first short sides may be referred to as second short sides. A raised part214is formed at the second side of each angle block213aand213b. The protrusion212of the first angle block213ais put on and is combined with the raised part214of the second angle block213b.

The raised part214has a stepped shape corresponding to the width and thickness of the protrusion212. Raised part sides214aare formed at both sides of the raised part214.

A plurality of holes may be formed in each of the angle blocks213aand213bto decrease the weight of the angle block module210. Thus, it is possible to provide the variable display device100ofFIG. 2with a lighter weight.

As stated above, the shaft bearing217between the first and second block units211aand211badjacent to each other connects the first ends of the first links215aand the third ends of the second links215b.

Here, the shaft bearing217is disposed over the raised part214, and more particularly, over the raised part214of the second angle block213b, and both ends of the shaft bearing217are inserted into and guided by holes214b, which are formed at the raised part sides214aalong a length direction of the raised part sides214a, respectively.

Namely, the both ends of the shaft bearing217are inserted into the holes214bformed at the raised part sides214aand inserted into the bearing holes219of the first and second links215aand215b, respectively.

A roller217ais installed to the shaft bearing217. The shaft bearing217guides the protrusion212of the first angle block213asuch that the protrusion212of the first angle block213amay be inserted into the raised part214of the second angle block213badjacent to the protrusion212of the first angle block213a. Additionally, the shaft bearing217receives driving power due to the rectilinear motion transferred to the first and second links215aand215band vertically lifts the edges of the first and second angle blocks213aand213bwhich are adjacent to each other and in which the protrusion212is inserted into the raised part214.

Also, a groove214cmay be further formed in the raised part214to guide the roller217a. A stopping part214dmay be formed at an edge of the raised part214, and the shaft bearing217and the roller217amay be prevented from getting out of the raised part214.

The backcover system200may have a curved shape or a flat shape overall as the angle block module210may be driven such that the edges of the first and second angle blocks213aand213bmay be raised or lowered with the driving system220at the center.

Accordingly, the variable display device100ofFIG. 2according to the exemplary embodiment may be selectively varied and used in the flat mode and the curved mode by the backcover system200, which is installed at the rear surface of the backcover of the display panel module110ofFIG. 2.

Here, the flatness controlling unit300is installed at each angle block module210, which is disposed at each of both sides of the driving system220. The flatness controlling unit300improves the flatness of the variable display device100ofFIG. 2when the variable display device100ofFIG. 2is driven in the flat mode.

The flatness controlling unit300includes a wire310. The wire310is guided by and disposed in a flatness controlling groove320shown inFIG. 5F, which is formed at a side or at each of both sides of the angle blocks213of the angle block module210along a length direction of the angle blocks213.

One end of the wire310is connected to the motor221and the other end of the wire310is connected to an end of the angle block module210disposed at each of both sides of the driving system220. The flatness controlling unit300includes a tension adjusting part A, which is composed of a portion of the wire310and a spring330that is connected to the portion of the wire310, as illustrated inFIGS. 3 and 5G.

That is, in the flatness controlling unit300guided by the flatness controlling groove320ofFIG. 5F, which is formed along the length direction of the angle block module210, one end of the spring330is connected to a first side of the portion of the wire310and the other end of the spring330is connected to a second side of the portion of the wire310. A length of the spring330is shorter than a length of the portion of the wire310.

The wire310installed in the angle block module210is disposed at each of both sides of the driving system220and has a length corresponding to a length of the rear surface of the display panel module110ofFIG. 2in a curved mode.

In the variable display device100ofFIG. 2according to the exemplary embodiment, when it is driven as the flat mode, the flatness of the variable display device100ofFIG. 2is further improved by the flatness controlling unit300.

Here, a process of changing the variable display device100ofFIG. 2from the flat mode to the curved mode using the backcover system200will be described in detail with reference to drawings.

FIGS. 5A to 5Gare views schematically illustrating a process of changing a variable display device according to an exemplary embodiment from a flat mode into a curved mode. For convenience of explanation, the angle block module will be mainly described.

InFIG. 5A, the backcover system200is installed at the rear surface of the backcover of the display panel module110ofFIG. 2along a width of the backcover. The angle block module210of the backcover system200ofFIG. 4is disposed at each of both sides of the display panel module110with the driving system220in the center.

The block units211a,211b, and211cof the angle block module210are fixed to the backcover of the display panel module110ofFIG. 2.

Here, if the motor221is driven clockwise, the gear223rotates clockwise, and the rotatory power of the gear223is delivered to the first links215aof the angle block module210.

Guide grooves223aare formed in the gear223and correspond to the rotatory power. The first links215aare connected to the guide grooves223a. Thus, when the gear223rotates, the first links215amove from first ends of the guide grooves223ato second ends of the guide grooves223a, whereby the rotatory power of the gear223is delivered to the first links215a.

Because the angle block module210is installed at each of both sides of the driving system220, two guide grooves223aare formed in the gear and face each other, and each of the guide grooves223ais connected to the first links215aof the angle block module210at both sides of the driving system220.

The rotatory power delivered to the first links215ais changed into rectilinear motion, and as shown inFIG. 5B. The first links215amove away from the driving system220, i.e., toward +X-axis direction defined inFIGS. 5B-D. The force generated by movement of the first links215acontradicts the stationary force of the first and second angle blocks213aand213bfixed to the backcover of the display panel module110ofFIG. 2, and the first ends of the first links215aand the third ends of the second links215bconnected to each other are lifted toward a direction perpendicular to the moving direction of the first links215a, i.e., toward +Z-axis direction defined inFIGS. 5B-D.

Because the first ends of the first links215aand the third ends of the second links215bare lifted toward the direction perpendicular to the moving direction of the first links215a, the shaft bearing217, which connects the first ends of the first links215aand the third ends of the second links215b, is also lifted in the +Z-axis direction.

In this action, the shaft bearing217is lifted, and thus, the protrusion212of the first angle block213ais inserted into the raised part214of the second angle block213badjacent to the first angle block213aby the shaft bearing217.

In addition, when the protrusion212of the first angle block213ais inserted into the raised part214of the second angle block213badjacent to the first angle block213a, the shaft bearing217is lifted in succession toward the +Z-axis direction. Therefore, as shown inFIGS. 5C and 5D, the first short side of the first angle block213awhere the protrusion212is formed and the second short side of the second angle block213bwhere the raised part214is formed are lifted together in the +Z-axis direction.

The second short side of the second angle block213bis lifted in the +Z-axis direction, and thus, the first short side of the second angle block213bis lowered in −Z-axis direction due to counteraction.

The protrusion212is formed to be inclined toward the backcover of the display panel module110ofFIG. 2, i.e., in the −Z-axis direction defined in theFIGS. 5B-D, with a predetermined angle from one end of the protrusion212at the first short side to the other end of the protrusion212. When the protrusion212is inserted into the raised part214, the second short side of the second angle block213bis pressed by the protrusion212.

Accordingly, the first short side of the second angle block213bis further lowered in the −Z-axis direction.

While the first short side of the second angle block213bis moved in the −Z-axis direction, the second short side of the third angle block213cis also moved in the −Z-axis direction. Here, the second short side of the third angle block213cis adjacent to the second angle block213band the raised part214is formed at the second short side of the third angle block213c, whereby the protrusion212formed at the first short side of the second angle block213bis inserted into the raised part214of the third angle block213c.

Moreover, although not shown in the figures, the first short side of the third angle block213cis similarly moved in the +Z-axis direction due to counteraction, and thus, the angle blocks213a,213b, and213care linked and driven together.

The first and second short sides of the angle blocks213a,213b, and213care lifted or lowered, and an angle of the display panel module110at which the angle blocks213a,213b, and213care fixed is controlled by a lifted angle or a lowered angle of the angle blocks213a,213b, and213c.

In addition, the angle block module210, which is installed at the other side of the driving system220, is also driven as described above. As a result of these movements, the display panel module110with the backcover system200installed, as shown inFIG. 5E, has a curved shape with respect to a normal direction.

Accordingly, the curved mode is implemented.

Here, the angle block module210is composed of the block units211a,211b, and211c, which includes angle blocks213a,213b, and213c, respectively. Thus, each of the block units211a,211b, and211cfunctions as a joint, and the backcover system200of the present invention can have an accurate curvature in the curved mode.

Namely, since the lifted angle or the lowered angle of each of the angle blocks213a,213b, and213ccan be controlled, an expected curvature can be obtained. The number and size of the angle block modules210used can vary depending on the size of the display panel module and the amount of curvature desired.

As illustrated inFIGS. 5F-G, the flatness controlling unit300is installed at each angle block module210disposed at each of both sides of the driving system220, and the flatness controlling unit300includes the wire310having one end connected to the motor221of the driving system220and the other end connected to the end of the angle block module210. When the display panel module110has a curved shape in the curved mode, as shown inFIG. 5F, the spring330is lengthened due to elasticity, and at the same time, the wire310of the flatness controlling unit300is pulled and tightened along the rear surface of the display panel module110having the curved shape.

Therefore, tension is given to the wire310of the flatness controlling unit300, and the flatness controlling unit300applies pulling force from both ends of the display panel module110along the length direction to the display panel module110implemented in the curved mode.

From this, when the variable display device100is implemented in the curved mode, the flatness of a central portion of the curved display panel module110may be improved.

Here, the tension of the wire310applied through the flatness controlling unit300is smaller than the force applied through the angle block module210such that the display panel module110is curved. Thus, only the central portion of the variable display device100may have improved flatness when it is implemented in the curved mode.

When the variable display device100is changed from the curved mode into the flat mode, the motor221of the driving system220is driven counterclockwise. The gear223rotates counterclockwise, and the first links215adisposed at the second ends of the guide grooves223amove to the first ends of the guide grooves223a, whereby the rotatory power of the gear223is delivered to the first links215a.

The rotatory power delivered to the first links215ais changed into the rectilinear motion, and the first links215amove toward the driving system220, i.e., toward the −X-axis direction defined in theFIGS. 5B-D.

The first links215amove backwards, and the shaft bearing217lifted in the +Z-axis direction is lowered. Simultaneously, the protrusion212of the first angle block213ais separated from the raised part214of the second angle block213badjacent to the first angle block213a, and the first short side of the first angle block213aand the second short side of the second angle block213bare also lowered.

The second short side of the second angle block213bis lowered, and thus, the first short side of the second angle block213bis lifted in the +Z-axis direction due to counteraction.

From this, the angle blocks213a,213b, and213care linked and driven together, and the angle block module210is oriented on a straight line.

Accordingly, the display panel module110is implemented in the flat mode.

Also, when the display panel module110is flat in the flat mode, as shown inFIG. 5G, the lengthened spring330of the flatness controlling unit300is restored to its original condition, and the wire310of the flatness controlling unit300, which was pulled and tightened along the rear surface of the curved display panel module110, is relieved of tension and sags.

The sagging only occurs in the tension adjusting part A ofFIG. 3because of the spring330. When the wire310sags, the wire310is prevented from being drawn into the motor221.

Here, a length of the wire310, excluding the portion of the wire310connected to the spring330, and a length of the wire330to which the tension is not given and which is not lengthened, correspond to the length of the rear surface of the display panel module110in the flat mode.

If the motor221is further driven counterclockwise, the tension is applied to the spring330, which is not lengthened, and the wire310of the flatness controlling unit300.

From this, the flatness controlling unit300applies pulling force from both ends of the display panel module110along the length direction to the display panel module110implemented in the flat mode. Therefore, the display panel module110has improved flatness due to the pulling force from both ends of the length direction when it is implemented in the flat mode.

More particularly, in general, when the variable display device100is repeatedly changed between the flat mode and the curved mode, repeated stress is concentrated at the central portion of the variable display device100at which the driving system220is installed with the angle block module210at both sides thereof.

Accordingly, if the variable display device100with concentrated stress is continuously changed between the flat mode and the curved mode, rigidity of the central portion of the variable display device100with concentrated stress is degraded, and there occurs plastic deformation such as bending of the variable display device100.

Then, when the variable display device100is changed from the curved mode into the flat mode, the flatness of the central portion of the variable display device100is reduced because of the plastic deformation of the central portion of the variable display device100.

Therefore, the variable display device100according to the exemplary embodiment of the present invention includes the backcover system200with the flatness controlling unit300. Since the pulling force from both ends of the length direction of the display panel module110is applied to the display panel module110by the wire310of the flatness controlling unit300, the flatness can be improved even if the plastic deformation occurs at the central portion of the variable display device100.

In the meantime, the wire310of the flatness controlling unit30may be equipped with a tightening apparatus for adjusting the tension of the wire310, such as a turnbuckle340. The turnbuckle340may include screw rods at both ends of its length direction. For example, a male screw of one end may be a right-handed screw, and a male screw of the other end may be a left-handed screw. If a component having a female screw, that is, an adjusting nut rotates, the two male screws approach each other. If the adjusting nut rotates oppositely, the two male screws go far away from each other and adjusting tension in the wire.

When the tension is weakened by long-term use of the wire310of the flatness controlling unit300, or other adjustment is needed, the tension of the wire310can be adjusted by the turnbuckle340.

As mentioned above, the variable display device100of the present disclosure can be selectively varied and used as the flat mode or the curved mode by the backcover system200, which is installed at the rear surface of the display panel module110.

Namely, in an open space such as an outdoor square or in an indoor square such as airports or terminals, for example, the variable display device of the present disclosure can be implemented in the flat mode such that the variable display device has wide viewing angles and news or advertisements from images displayed by the display panel are provided to many viewers. Alternatively, the variable display device of the present disclosure can be implemented in the curved mode such that the viewer is further immersed in watching, watches more realistic images, and feels comfortable.

Accordingly, the user or provider can selectively use the variable display device100of the present invention in the flat mode or the curved mode for the convenience of the user as occasion demands.

Here, when the variable display device100of the present disclosure is changed between the flat mode and the curved mode, vibrations and noises hardly occur. Since the backcover system200is composed of the driving system220and the angle block module210and the angle block module210is directly installed at the rear surface of the backcover of the display panel module110, the volume and weight of the backcover system200are minimized in the variable display device100, and the variable display device100has a relatively light weight and thin profile.

It is desirable that the backcover system200is installed at both sides of the display panel module110along the length direction of the display panel module110.

Specially, in the variable display device100according to the exemplary embodiment of the present disclosure, the backcover system200may include the flatness controlling unit300. The pulling force from both ends of the length direction of the display panel module110is applied to the display panel module110by the wire310of the flatness controlling unit300, and thus the flatness can be improved even if the plastic deformation occurs at the central portion of the variable display device100.