Patent Description:
As the information society has developed, the demand for display device is increasing in various forms, and accordingly, in recent years, various display devices such as a liquid crystal display (LCD), plasma display panel (PDP), electroluminescent display (ELD), vacuum fluorescent display (VFD), and the like have been studied and used.

Thereamong, a display device using an organic light emitting diode (OLED) has excellent luminance and viewing angle characteristics in comparison with a liquid crystal display device and does not require a backlight unit, thereby being implemented in an ultrathin type.

In addition, a flexible display panel can be bent or wound around a roller. The flexible display panel may be used to implement a display device that unfolds on a roller or winds around the roller. Many studies have been made on a structure for winding a flexible display panel around a roller or unwinding the flexible display panel from the roller.

<CIT> discloses a screen unit including: a screen which has a first side and a second side opposing to each other in a first direction and extending substantially in parallel with each other; a first supporting portion extending along the first side to support the first side; a second supporting portion extending along the second side to support the second side; and a plurality of connecting mechanisms each of which extends between the first supporting portion and the second supporting portion, and expands and contracts in the first direction to move the second supporting portion close to and away from the first supporting portion, wherein the plurality of connecting mechanisms are disposed in parallel with the first supporting portion, and are located almost linearly symmetric with respect to a center line connecting approximately the center of the first side and approximately the center of the second side.

<CIT> discloses a display device comprising: a housing; a roller disposed in the housing to be rotatable; a flexible display wound on or unwound from the roller; a first arm connected to the flexible display; an arm supporter provided in the housing; an arm shaft rotatably supported by the arm supporter; a second arm connected to an arm axis and rotating with the arm axis to rotate the first arm; a rotary mechanism connected to the second arm to rotate the second arm about the arm axis; and an angle sensor module connected to at least one of the arm axis and the second arm.

It is an object of the present disclosure to solve the above and other problems.

It is another object of the present disclosure to secure structural rigidity for preventing drooping of a display device.

It is another object of the present disclosure to secure structural rigidity for preventing twisting of the display device.

It is a further object of the present disclosure to provide a driving mechanism of a rollable display device.

In accordance with the present disclosure, the above and other objects can be accomplished by the provision of a display device as defined in appended claim <NUM>.

The effects of the display device according to the present disclosure will be described.

According to at least one of the embodiments of the present disclosure, it is possible to secure structural rigidity for preventing drooping of a display device.

According to at least one of the embodiments of the present disclosure, it is possible to secure structural rigidity for preventing twisting of the display device.

According to at least one of the embodiments of the present disclosure, it is possible to provide a driving mechanism of a rollable display device.

However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by illustration only, since various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

<FIG> are views showing examples of a display device according to embodiments of the present disclosure.

Description will now be given in detail according to exemplary embodiments disclosed herein, with reference to the accompanying drawings. For the sake of brief description with reference to the drawings, the same or equivalent components may be denoted by the same reference numbers, and description thereof will not be repeated.

In general, suffixes such as "module" and "unit" may be used to refer to elements or components. Use of such suffixes herein is merely intended to facilitate description of the specification, and the suffixes do not have any special meaning or function.

In the present disclosure, that which is well known to one of ordinary skill in the relevant art has generally been omitted for the sake of brevity. The accompanying drawings are used to assist in easy understanding of various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings.

It will be understood that when an element is referred to as being "connected with" another element, there may be intervening elements present. In contrast, it will be understood that when an element is referred to as being "directly connected with" another element, there are no intervening elements present.

A singular representation may include a plural representation unless context clearly indicates otherwise.

In the following description, even if an embodiment is described with reference to a specific figure, if necessary, reference numeral not shown in the specific figure may be referred to, and reference numeral not shown in the specific figure is used when the reference numeral is shown in the other figures.

For horizontally symmetrical or vertically symmetrical components shown in the drawings referred to in the following description, the description of a one-side part of each component may be equally applied to the description of an other-side part thereof.

Referring to <FIG>, a display device <NUM> includes a display unit <NUM> and a housing <NUM>. The housing <NUM> may have an internal space. At least a portion of the display unit <NUM> may be located inside the housing <NUM>. At least a portion of the display unit <NUM> may be located outside the housing <NUM>. The display unit <NUM> may display a screen.

The direction parallel to the longitudinal direction of the housing <NUM> may be referred to as a first direction DR1, a leftward direction, or a rightward direction. The direction in which the display unit <NUM> displays a screen may be referred to as a forward direction or the front. The direction opposite to the direction in which the display unit <NUM> displays the screen may be referred to as a rearward direction or the rear. The direction parallel to the height direction of the display device <NUM> may be referred to as a second direction DR2, an upward direction, or a downward direction.

A third direction DR3 may be a direction perpendicular to the first direction DR1 and/or the second direction DR2. The first direction DR1 and the second direction DR2 may be collectively referred to as a horizontal direction. In addition, the third direction DR3 may be referred to as a vertical direction. A leftward-rightward direction LR may be parallel to the first direction DR1, and an upward-downward direction UD may be parallel to the second direction DR2.

Referring to <FIG>, the display unit <NUM> may be entirely located inside the housing <NUM>. At least a portion of the display unit <NUM> may be located outside the housing <NUM>. The degree to which the display unit <NUM> is exposed to the outside of the housing <NUM> may be adjusted as necessary.

Referring to <FIG>, the display unit <NUM> includes a display panel <NUM> and may include a plate <NUM>. The display panel <NUM> is flexible. For example, the display panel <NUM> may be an organic light emitting display (OLED).

The display panel <NUM> may have a front surface for displaying an image. The display panel <NUM> may have a rear surface facing the front surface. The front surface of the display panel <NUM> may be covered with a light transmissive material. For example, the light transmissive material may be a synthetic resin or film.

The plate <NUM> may be coupled, fastened, or attached to the rear surface of the display panel <NUM>. The plate <NUM> may include a metal material. The plate <NUM> may be referred to as a module cover <NUM>, a cover <NUM>, a display panel cover <NUM>, a panel cover <NUM>, or an apron <NUM>.

Referring to <FIG>, the plate <NUM> may include a plurality of segments 23c. A magnet <NUM> may be located inside a recess <NUM> of the segment 15c. The recess <NUM> may be located on a surface of the segment 23c facing the display panel <NUM>. The recess <NUM> may be located in the front surface of each segment <NUM>. Since the magnet <NUM> is accommodated inside the recess <NUM>, the magnet <NUM> may not protrude from the segment 23c. The display panel <NUM> may be flat without being wrinkled even when it is in contact with the segment 23c.

Referring to <FIG>, a bead <NUM> may be formed in the upper surface of the segment 23b. The bead <NUM> may have a shape recessed inwardly of the segment 23b. For example, the bead <NUM> may be formed by pressing the segment 23b. A plurality of beads <NUM> may be formed on the segment 23b. The plurality of beads <NUM> may be spaced apart from each other. The bead <NUM> may enhance the rigidity of the segment 23b. The bead <NUM> can prevent the shape of the segment 23b from being deformed due to external impact. The segment 23b may be fixed to the rear of the display panel <NUM> via an adhesive member <NUM>. For example, the adhesive member <NUM> may be double-sided tape.

Referring to <FIG>, a source PCB 21b may be located under the module cover <NUM>. In the case of roll-down or roll-up, the position of the source PCB 21b may be changed with the movement of the module cover <NUM>. An FFC cable 21a may be located in the central part of the module cover <NUM> in the first direction. The FFC cable 21a may be located in both ends of the module cover <NUM> in the first direction.

Referring to <FIG>, a segment 23d may include a depression <NUM> recessed inwardly of the segment 23d. The depression <NUM> may form a space between the display panel <NUM> and the module cover <NUM>. The FFC cable 21a may be accommodated in a space formed by the depression <NUM>. In addition, the depression <NUM> may improve the rigidity of the segment 23d. The bead <NUM> may be located on the segment 23d excluding a portion where the depression <NUM> is located. The position of the depression <NUM> may not overlap the position of the bead <NUM> in order to prevent a reduction in rigidity of the segment 23d.

Referring to <FIG>, a penetrating portion <NUM> may be located at the central part of a segment 23e in the first direction. The penetrating portion <NUM> may penetrate the central part of the segment 23e in the second direction. That is, the penetrating portion <NUM> may be a hole located in the segment 23e. The penetrating portion <NUM> may be a portion where the FFC cable 21a is located. Since the penetrating portion <NUM> is formed in the segment 23e, the thickness of the segment 23e may be reduced in comparison with the case where the FFC cable 21a is located in the depression <NUM> (see <FIG>). The bead <NUM> may be located on the segment 23e excluding a portion where the penetrating portion <NUM> is located. The position of the penetrating portion <NUM> may not overlap the position of the bead <NUM> in order to prevent a reduction in rigidity of the segment 23e.

Referring to <FIG>, a top case <NUM> may cover the source PCB 21b and a bar <NUM> as well as the display panel <NUM> and the module cover <NUM>. One surface of the bar <NUM> may be coupled to the rear surface of the module cover <NUM>, and the other surface thereof may be coupled to the source PCB 21b. The bar <NUM> may be fixed to the module cover <NUM> to support the source PCB 21b.

The distal end of the FFC cable 21a may be connected to a timing controller board <NUM> (see <FIG>) inside a roller <NUM> (see <FIG>). The FFC cable 21a may be wound around or unwound from the roller <NUM> together with the display unit <NUM>.

A portion of the FFC cable 21a may be located between the display panel <NUM> and the module cover <NUM>. The portion of the FFC cable 21a located between the display panel <NUM> and the module cover <NUM> may be referred to as a first portion 21a1. The first portion 21a1 may be located in the depression <NUM> formed by the plurality of segments 23d. Alternatively, the first portion 21a1 may be accommodated in the depression <NUM> formed by the plurality of segments 23d.

A portion of the FFC cable 21a may penetrate a segment 23f. The portion of the FFC cable 21a that passes through the segment 23f may be referred to as a second portion 21a2. The segment 23f may include a first hole 23fh1 formed in the front surface and a second hole 23fh2 formed in the rear surface. The first hole 23fh1 and the second hole 23fh2 may be connected to each other to form a single hole 23fh. The hole 23fh may penetrate the segment 23f in the third direction. The second portion 21a2 may extend through the hole 23fh. The hole 23fh may be referred to as a connection hole 23fh.

The distal end of the FFC cable 21a may be electrically connected to the source PCB 21b. A part of the FFC cable 21a may be located in the rear surface of the module cover <NUM>. The portion of the FFC cable 21a located in the rear surface of the module cover <NUM> may be referred to as a third portion 21a3. The third portion 21a3 may be electrically connected to the source PCB 21b.

The third portion 21a3 may be covered by the top case <NUM>. Accordingly, the third portion 21a3 may not be exposed to the outside.

Referring to <FIG>, the FFC cable 21a may be connected to the timing controller board <NUM> mounted in the roller <NUM>. A penetrating hole <NUM> may be formed on the roller <NUM>, and the FFC cable 21a may be connected to the timing controller board <NUM> through the penetrating hole <NUM>.

The penetrating hole <NUM> may be located in one side of the roller <NUM> and may penetrate an outer circumferential portion of the roller <NUM>. The FFC cable 21a may be connected to one side of the timing controller board <NUM> through the penetrating hole <NUM>.

Even when the FFC cable 21a is located in the outer circumference of the roller <NUM>, it may maintain the connection with the timing controller board <NUM> due to the penetrating hole <NUM>. Accordingly, the FFC cable 21a may rotate together with the roller <NUM> to prevent twisting.

A portion of the FFC cable 21a may be wound around the roller <NUM>. The portion of the FFC cable 21a wound around the roller <NUM> may be referred to as a fourth portion 23a4. The fourth portion 23a4 may be in contact with the outer circumferential surface of the roller <NUM>.

A portion of the FFC cable 21a may pass through the penetrating hole <NUM>. The portion of the FFC cable 21a passing through the penetrating hole <NUM> may be referred to as a fifth portion 23a5.

The distal end of the FFC cable 21a may be electrically connected to the timing controller board <NUM>. A portion of the FFC cable 21a may be located inside the roller <NUM>. The portion of the FFC cable 21a located inside the roller <NUM> may be referred to as a sixth portion 23a6. The sixth portion 23a6 may be electrically connected to the timing controller board <NUM>.

Referring to <FIG>, the display panel <NUM> may be connected to the roller <NUM>. The display panel <NUM> in wound around or unwound from the roller <NUM>. The display panel <NUM> may be electrically connected to the plurality of source PCBs 21b. The plurality of source PCBs 21b may be spaced apart from each other.

A source chip on film (COF) <NUM> may connect the display panel <NUM> and the source PCB 21b. The source COF <NUM> may be located at a long side of the display panel <NUM>. The roller <NUM> may include a first part <NUM> and a second part <NUM>. The first part <NUM> and the second part <NUM> may be fastened by a screw. The timing controller board <NUM> may be mounted in the roller <NUM>.

The source PCB 21b may be electrically connected to the timing controller board <NUM>. The timing controller board <NUM> may send digital video data and a timing control signal to the source PCB 21b.

The cable 21p may electrically connect the source PCB 21b and the timing controller board <NUM>. For example, the cable 21p may be a flexible flat cable (FFC). The cable 21p may penetrate a hole 21n. The hole 21n may be formed in a seating portion <NUM> or the first part <NUM>. The cable 21p may be located between the display panel <NUM> and the second part <NUM>.

The seating portion <NUM> may be formed in an outer circumference of the first part <NUM>. The seating portion <NUM> may be formed by stepping a portion of the outer circumference of the first part <NUM>. The seating portion <NUM> may form a space B. When the display unit <NUM> is wound around the roller <NUM>, the source PCB 21b may be accommodated in the seating portion <NUM>. Since the source PCB 21b is accommodated in the seating portion <NUM>, the source PCB 21b may not be twisted or bent, and durability may be improved.

Referring to <FIG>, a frame <NUM> may include a first base <NUM>, a second base <NUM>, and a vertical portion <NUM>. The frame <NUM> may be referred to as a main frame. The frame <NUM> may be mounted in the housing <NUM> (see <FIG>). The frame <NUM> may extend long in the leftward-rightward direction LR of the housing <NUM>, and may be mounted to the housing <NUM>.

The first base <NUM> may be a long plate. The vertical portion <NUM> may extend from a long side of the first base <NUM> in the longitudinal direction of the first base <NUM>. A first rib 101a and a second rib 101b may be formed on the first base <NUM>. The first rib 101a may be located adjacent to the vertical portion <NUM>, and the second rib 101b may be opposite the vertical portion <NUM> with respect to the first rib 101a.

The second base <NUM> may be formed at the distal end of the vertical portion <NUM>. The second base <NUM> may have a third rib 103a and a fourth rib 103b. The third rib 103a may be formed at the distal end of one long side of the second base <NUM>, and the fourth rib 103b may be formed at the distal end of the other long side of the second base <NUM>. Consequently, it is possible to secure rigidity of the frame <NUM> against drooping or bending.

Referring to <FIG> and <FIG>, a tower 120A may be mounted on the frame <NUM>. The tower 120A may be referred to as a sub frame 120A. The tower 120A may include a first beam <NUM>, a second beam <NUM>, and a clamp <NUM>. The first beam <NUM> may extend long in the upward-downward direction UD. The second beam <NUM> may extend long in the upward-downward direction UD while intersecting the first beam <NUM>. The width of the second beam <NUM> may gradually decrease in the longitudinal direction. A plurality of second beams <NUM> may be provided. The clamp <NUM> may be formed at the distal end of the tower 120A. Bosses 123a and 123b may be formed at the side surface of the tower 120A. A plurality of bosses 123a and 123b may be provided. The first boss 123a may be located adjacent to the middle of the first beam <NUM>, and the second boss 123a may be located at the first beam <NUM> so as to be adjacent to the clamp <NUM>.

Referring to <FIG>, a link mount 210a may be mounted on the frame <NUM>. For example, the link mount 210a may be mounted on the first base <NUM> (see <FIG>). The link mount 210a may include a first part 211a and a second part 212a. The first part 211a may be a plate, and the second part 212a may be a plate. The first part 211a may be spaced apart from the second part 212a by a predetermined distance.

Links 220a and 230a may include an upper arm 230a and a lower arm 220a. The upper arm 230a may be referred to as a first arm 230a, and the lower arm 220a may be referred to as a second arm 220a. One end of the upper arm 230a may be connected to one end of the lower arm 220a via a joint 240a. The other end of the lower arm 220a may be pivotably coupled to the link mount 210a. For example, the other end of the lower arm 220a may be inserted between the first part 211a and the second part 212a, and may be axially coupled to the first part 211a and the second part 212a so as to rotate about a shaft <NUM>11a. A first gear box 301a may be installed at the link mount 210a. A second gear box 302a and/or a third gear box 303a may be mounted on the first base <NUM> of the frame <NUM>.

Referring to <FIG>, a link gear 310a and a worm gear <NUM> are mounted in the first gearbox 301a. The link gear 310a may be engaged with the worm gear <NUM>. The worm gear 320a is rotatably installed in the first gear box 301a. A transmission shaft 321a may be rotatably installed in the first gear box 301a. The transmission shaft 321a may be inserted into a first bearing 322a and a second bearing 323a. The worm gear 320a may be fixed to the transmission shaft 321a between the first bearing 322a and the second bearing 323a. The first bearing 322a and the second bearing 323a may be fixed to the first gear box 301a. The second gear box 302a may be mounted on the first base <NUM> of the frame <NUM> in the state of being adjacent to the first gear box 301a.

The transmission shaft 321a may be rotatably installed in the second gear box 302a. A third bearing 332a may be fixed in the second gear box 302a. The third bearing 332a may be located adjacent to the distal end of the transmission shaft 321a. A first transmission gear 330a may be rotated with the transmission shaft 321a. The first transmission gear 330a may be located between the third bearing 332a and the second bearing 323a.

The third gear box 303a may be mounted on the first base <NUM> of the frame <NUM> in the state of being adjacent to the second gear box 302a. A driving shaft 343a may be rotated in the third gear box 303a. A fourth bearing 342a may be fixed in the third gear box 303a. The driving shaft 343a may be inserted into the fourth bearing 342a so as to be rotated in the fourth bearing 342a. The driving shaft 343a may be inserted into a second transmission gear 341a. The second transmission gear 341a may be rotated with the driving shaft 343a. The second transmission gear 341a may be engaged with the first transmission gear 330a. The first transmission gear 330a may be referred to as a driving gear 330a.

Referring to <FIG>, a guide rail 213a may be located at the inner surface of the first part 211a and/or the second part 212a. The guide rail 213a may be fixed to the first part 211a and/or the second part 212a. The lower arm 220a may be turned about the shaft 311a on the guide rail 213a while being engaged with the guide rail 213a. When the links 220a and 230a are driven, therefore, the links 220a and 230a may move along a predetermined track without shaking or twisting.

Referring to <FIG>, a motor M is mounted on the first base <NUM> of the frame <NUM>. Motor shafts MS1 and MS2 may be installed at opposite sides of the motor M, whereby power may be provided to the opposite sides of the motor M. A left driving shaft 343a may be connected to the left motor shaft MS1 of the motor M, and a right driving shaft 343b may be connected to the right motor shaft MS2 of the motor M. A left coupling 350a may connect the left driving shaft 343a and the left motor shaft MS1 to each other. For example, couplings 350a and 350b may be universal joints. The left driving shaft 343a may be rotatably inserted into a left support 104a so as to be rotatable.

The left support 104a may be mounted on the first base <NUM> of the frame <NUM>, and may support the left driving shaft 343a. The right driving shaft 343b may be rotatably inserted into a right support 104b so as to be rotatable. The right support 104b may be mounted on the first base <NUM> of the frame <NUM>, and may support the right driving shaft 343b.

The left motor shaft MS1 may be inserted into a sensor plate <NUM>. The sensor plate <NUM> may be rotated with the left motor shaft MS1. For example, the sensor plate <NUM> may have a disc-shaped rotator 361a and a plurality of teeth 361b protruding from the outer circumferential surface of the rotator 361a in the radial direction. A sensor <NUM> may sense rotation of the sensor plate <NUM>. For example, the sensor <NUM> may be a photo sensor. Consequently, the number of rotations of the motor M may be sensed.

Referring to <FIG> and <FIG>, a pipe <NUM> may be coupled to the tower <NUM>. The pipe <NUM> may extend long, and may be disposed parallel to the frame <NUM>. The pipe <NUM> may be inserted into and fixed to the clamp <NUM> (see <FIG>) of the tower <NUM>. A plurality of towers <NUM> may be provided, and may be mounted on the first base <NUM> of the frame <NUM>. The clamp <NUM> having the pipe inserted thereinto may be tightened by a fastening member.

A first tower 120A may be located at the left side of the frame <NUM>. A fourth tower 120D may be located at the right side of the frame <NUM>. A second tower 120B may be located between the first tower 120A and the fourth tower 120D, and a third tower 120C may be located between the second tower 120B and the fourth tower 120D. The number of towers <NUM> may be variously changed.

The distance between the first tower 120A and the second tower 120B may be substantially equal to the distance between the third tower 120C and the fourth tower 120D. The distance between the first tower 120A and the second tower 120B may be less than the distance between the second tower 120B and the third tower 120C.

Referring to <FIG>, a left link mount 210a may be located between the first tower 120A and the second tower 120B so as to be adjacent to the first tower 120A. A right link mount 210b may be located between the third tower 120C and the fourth tower 120D so as to be adj acent to the fourth tower 120D. The motor M may be located between the second tower 120B and the third tower 120C.

A first left gear box 301a may be fixed on the left link mount 210a. A second left gear box 302a may be located among the left link mount 210a, the first left gear box 301a, and the second tower 120B so as to be adjacent to the first left gear box 301a. A third left gear box 303a may be located between the first left gear box 301a and the second tower 120B so as to be adjacent to the second left gear box 302a and the first left link mount 210a.

A first right gear box 301b may be fixed on the right link mount 210b. A second right gear box 302b may be located among the right link mount 210b, the first right gear box 301b, and the third tower 120C so as to be adjacent to the first right gear box 301b. A third right gear box 303b may be located between the first right gear box 301b and the third tower 120B so as to be adjacent to the second right gear box 302b and the first right link mount 210b.

The left driving shaft 343a may transmit power provided by the motor M to the third left gear box 303a. The right driving shaft 343b may transmit power provided by the motor M to the third right gear box 303b. The left driving shaft 343a may receive power from the motor via a left joint 350a while being supported by the left support 104a, and the right driving shaft 343b may receive power from the motor via a right joint 350b while being supported by the right support 104b.

Left links 220a, 230a, and 240a may be pivotably connected to the left link mount 210a, and may move downwards while being unfolded or upwards while being folded. Right links 220b, 230b, and 240b may be pivotably connected to the right link mount 210b, and may move downwards while being unfolded or upwards while being folded. The left links 220a, 230a, and 240a and the right links 220b, 230b, and 240b may move downwards to the same height while being unfolded or upwards to the same height while being folded.

Consequently, power transmission of the display device may be achieved in the minimum space at high efficiency.

Referring to <FIG> and <FIG>, a panel roller <NUM> is mounted on the frame <NUM>. The panel roller <NUM> may be fixed on the first base <NUM>. The panel roller <NUM> may be located in front of the towers <NUM> (see <FIG>) and the pipe <NUM>. A guide roller <NUM> may be coupled to a roller frame <NUM>. The guide roller <NUM> may guide motion of the display panel <NUM> (see <FIG>) and the module cover <NUM>. The guide roller <NUM> may extend long in the leftward-rightward direction of the module cover <NUM>.

The guide roller <NUM> may have a shaft <NUM>, a roller <NUM>, and a fixing plate <NUM>. The shaft <NUM> may be supported by the roller frame <NUM>. The roller frame <NUM> may have a shaft recess <NUM> formed by cutting out a portion of the roller frame <NUM>, and the shaft <NUM> may be inserted into the shaft recess <NUM>. The roller <NUM> may surround the outer circumferential surface of the shaft <NUM>, and may be rotated in the shaft recess <NUM>. The fixing plate <NUM> may be fixed to the roller frame <NUM> via a fastening member (not shown).

Referring to <FIG> and <FIG>, the side cover <NUM> may be coupled to the frame <NUM> and the pipe <NUM> while facing the outer surface of the roller frame <NUM>. The side cover <NUM> may have a first fastening portion 35a. The first fastening portion 35a may be a plate protruding from the inner surface of the side cover <NUM>. The first fastening portion 35a may be fixed to the inner surface of the first base <NUM> of the frame <NUM>. For example, the first fastening portion 35a and the first base <NUM> of the frame <NUM> may be coupled to each other via a screw. The pipe <NUM> may be inserted into a coupling port <NUM> of the side cover <NUM>, and may be fixed to the side cover <NUM>. The side cover <NUM> may be referred to as a first side cover <NUM> or a left plate <NUM>.

The side cover <NUM> may have a second fastening portion 35b. The second fastening portion 35b may be a plate protruding from the inner surface of the side cover <NUM>. The second fastening portion 35b may be fixed to the outer surface of the second base <NUM> of the frame <NUM>. For example, the second fastening portion 35b and the second base <NUM> of the frame <NUM> may be coupled to each other via a screw.

Consequently, rigidity of the display device against drooping and twisting may be secured.

Referring to <FIG>, the side cover <NUM> may be referred to as a second side cover <NUM> or a right plate <NUM>. The description made with reference to <FIG> and <FIG> may be equally applied to the construction and structure of the second side cover <NUM>. At this time, the second side cover <NUM> may be symmetrical with the first side cover <NUM>.

Consequently, it is possible to secure rigidity of the display device against drooping and to secure rigidity of the display device against twisting.

Referring to <FIG> and <FIG>, the pipe <NUM> may have a neck <NUM> located adjacent to the distal end thereof, the neck <NUM> being formed at the outer circumferential surface of the pipe <NUM>. The pipe <NUM> may be coupled to the side covers <NUM> and <NUM>. The coupling port <NUM> may be formed inside each of the side covers <NUM> and <NUM>. The pipe <NUM> may be inserted or forcibly fitted into the coupling ports <NUM>, whereby the pipe <NUM> may be fixed to the side covers <NUM> and <NUM>. The coupling port <NUM> may be referred to as an end coupler <NUM>.

Referring to <FIG> and <FIG>, the coupling port <NUM> may have an outer cylinder <NUM> and an inner insert <NUM>. The outer cylinder <NUM> may have a hollow cylindrical shape. The outer cylinder <NUM> may have an outer surface 151c, a first inner surface 151a, and a second inner surface 151b. The first inner surface 151a may be parallel to the outer surface 151c. The second inner surface 151b may extend from the first inner surface 151a to the distal end of the outer cylinder <NUM> in the state of being inclined. The diameter of the second inner surface 151b may gradually increase from the diameter of the first inner surface 151a to the diameter of the outer surface 151c. The second inner surface 151b may be referred to as a guide surface 151b, and the first inner surface 151a may be referred to as a forcible fitting surface 151a. A protrusion <NUM> may be formed inside the outer cylinder <NUM>. For example, the protrusion <NUM> may be located at the border of the first inner surface 151a and the second inner surface 151b.

The inner insert <NUM> may be a rib extending from the side covers <NUM> and <NUM> (see <FIG>) toward the distal end of the second inner surface 151b of the outer cylinder <NUM>. The inner insert <NUM> may have a shape in which at least two ribs intersect. The inner insert <NUM> may have a first outer surface 152a and a second outer surface 152b. The first outer surface 152a may be spaced apart from the first inner surface 151a of the outer cylinder <NUM>, and may be parallel to the first inner surface 151a of the outer cylinder <NUM>. For example, the distance G1 between the first inner surface 151a of the outer cylinder <NUM> and the first outer surface 152a of the inner insert <NUM> may be substantially equal to or less than the thickness of the pipe <NUM>.

The second outer surface 152b of the inner insert <NUM> may extend from the first outer surface 152a to the distal end of the inner insert <NUM> in the state of being inclined. The second outer surface 152b of the inner insert <NUM> may be gradually distant from the first inner surface 151a and/or the second inner surface 151b of the outer cylinder <NUM>. For example, the inner insert <NUM> may have a wedge shape. The second outer surface 152b of the inner insert <NUM> may face the first inner surface 151a and the second inner surface 151b of the outer cylinder <NUM>.

The distance G1 between the first inner surface 151a of the outer cylinder <NUM> and the first outer surface 152a of the inner insert <NUM> may be less than the distance G2 between the first inner surface 151a of the outer cylinder <NUM> and the second outer surface 152b of the inner insert <NUM>. The distance G2 between the first inner surface 151a of the outer cylinder <NUM> and the second outer surface 152b of the inner insert <NUM> may be less than the distance G3 between the second inner surface 151b of the outer cylinder <NUM> and the second outer surface 152b of the inner insert <NUM>.

Referring to <FIG> and <FIG>, the pipe <NUM> may have a forcible fitting surface <NUM>. The forcible fitting surface <NUM> may be formed at the outer surface of the pipe <NUM> between the neck <NUM> of the pipe <NUM> and the distal end of the pipe <NUM>. The forcible fitting surface <NUM> may be a coarse surface. For example, the forcible fitting surface <NUM> may be a knurling portion.

The pipe <NUM> may be inserted or forcibly fitted into the coupling port <NUM>. The protrusion <NUM> may be inserted into the neck <NUM> of the pipe <NUM>. Consequently, fastening between the pipe <NUM> and the coupling port <NUM> may be more secured.

In <FIG>, the upward-downward direction UD and the leftward-rightward direction LR are described based on the state shown in <FIG>. Referring to <FIG>, a link bracket <NUM> may be pivotably connected to the first arm 230a. The link bracket <NUM> may include a support 951F and a coupling plate 951R.

The support 951F may have a horizontal body <NUM>, a joint <NUM> and 9512a, and cups 9513a, 9513b, and 9513c. The horizontal body <NUM> may have a bar shape extending long leftwards and rightwards. The joint <NUM> and 9512a may be formed at the lower side of the horizontal body <NUM>. The joint <NUM> and 9512a may include a fixing plate <NUM> and a pivot shaft 9512a.

A bearing <NUM> may be fastened to the pivot shaft 9512a. A plurality of bearings <NUM> may be provided. The plurality of bearings <NUM> may include a first bearing 960a and a second bearing 960b. The second bearing 960b may be stacked on the first bearing 960a. The first bearing 960a and the second bearing 960b may be fitted on the pivot shaft 9512a. Lubricating oil may be applied to the bearings <NUM>. Assembly of the bearings <NUM> and application of lubricating oil to the bearings <NUM> may be performed simultaneously with coupling between the first arm 230a and the link bracket <NUM>, but may be performed independently of fastening of other structures, whereby leakage of the lubricating oil may be prevented.

The fixing plate <NUM> may be located at the lowers side of the horizontal body <NUM> so as to be biased leftwards or rightwards. The fixing plate <NUM> may extend long to the lower side of the horizontal body <NUM>. The pivot shaft 9512a may be formed so as to protrude from one surface of the fixing plate <NUM>.

The cups 9513a, 9513b, and 9513c may be formed as the result of the upper surface of the horizontal body <NUM> being recessed. The cups 9513a, 9513b, and 9513c may be formed as the result of the upper surface of the horizontal body <NUM> being recessed and at the same time the front surface and the rear surface of the horizontal body <NUM> being open. For example, each of the cups 9513a, 9513b, and 9513c may generally have a U shape. The cups 9513a, 9513b, and 9513c may be sequentially disposed in the longitudinal direction of the horizontal body <NUM>. Consequently, it is possible to reduce concentration of stress and to eliminate fatigue fracture of the link bracket <NUM>.

The coupling plate 951R may include a support cover <NUM> and a joint cover <NUM>. The support cover <NUM> may be a plate formed so as to have a length corresponding to the length of the support 951F. The joint cover <NUM> may have the shape of a disc connected to the support cover <NUM> at the lower side of the support cover <NUM> in the state of being biased leftwards or rightwards. The coupling plate 951R may have a plurality of holes H and h.

The plurality of holes H and h may include first coupling holes h and second coupling holes H. The first coupling holes h may be provided for coupling between the support 951F, the coupling plate 951R, and first arms <NUM>. The second coupling holes H may be provided for coupling between a top case <NUM> (see <FIG>) and the link bracket <NUM>.

Referring to <FIG>, the cup 9513a may include a support portion 9513a1 and a guide portion 9513a2. The support portion 9513a1 may form the lower side of the cup 9513a, and the guide portion 9513a2 may form the upper side of the cup 9513a. For example, the support portion 9513a1 may have a semicircular shape or a fan shape, and the guide portion 9513a2 may extend from the support portion 9513a1 and may have the shape of left and right sides of an inverted trapezoid.

The top case <NUM> may include an inner bar 950I and a top cover 950T. The inner bar 950I may be located at the upper side or the upper end of the module cover <NUM>, and may be coupled to the module cover <NUM>. Coupling protrusions 950P1, 950P2, and 950P3 may be mounted on the outer surface of the inner bar 950I. A plurality of coupling protrusions 950P1, 950P2, and 950P3 may be provided. The number of coupling protrusions 950P1, 950P2, and 950P3 may correspond to the number of cups 9513a, 9513b, and 9513c. For example, the coupling protrusions 950P1 and 950P2 may be PEM nuts. The radii of the coupling protrusions 950P1, 950P2, and 950P3 may correspond to the radii of support portions 9513a1, 9513b1, and 9513c1 of the cups 9513a, 9513b, and 9513c.

Referring to <FIG> and <FIG>, the link bracket <NUM> may be assembled with the top case <NUM> in the state in which the link bracket <NUM> is coupled to the first arm 230a. At this time, the link bracket <NUM> may move to the top case <NUM> according to motion of the links 220a and 230a (see <FIG>) in the upward-downward direction. As the support 951F of the link bracket <NUM> approaches the top case <NUM>, the coupling protrusions 950P1, 950P2, and 950P3 may be inserted into the cups 9513a, 9513b, and 9513c (see <FIG>) of the support 951F. The coupling protrusions 950P1, 950P2, and 950P3 may be inserted into the cups 9513a, 9513b, and 9513c of the support 951F, and the link bracket <NUM> and the top case <NUM> may be fastened to each other via screws S2 (see <FIG>).

Consequently, the link bracket <NUM> may be naturally coupled to the top case <NUM> within a movable range of the links <NUM> and <NUM> without straining the joints of the links <NUM> and <NUM>.

Referring to <FIG>, the driving shaft 343a may transmit power provided by the motor M to the third gear box 303a. The driving shaft 343b may transmit power provided by the motor M to the third gear box 303b. The driving shaft 343a may receive power from the motor M via the joint 350a while being supported by the support 104a, and the driving shaft 343b may receive power from the motor M via the joint 350b while being supported by the support 104b.

The links 220a, 230a, and 240a may be pivotably connected to the link mount 210a (see <FIG>), and may move downwards while being unfolded or upwards while being folded. The links 220b, 230b, and 240b may be pivotably connected to the link mount 210b, and may move downwards while being unfolded or upwards while being folded. The links 220a, 230a, and 240a and the links 220b, 230b, and 240b may move downwards to the same height while being unfolded or upwards to the same height while being folded.

Consequently, power transmission of the display device may be achieved in the minimum space at high efficiency. In addition, the display panel <NUM> (see <FIG>) and the module cover <NUM> may be maintained flat in the state in which the display panel <NUM> and the module cover <NUM> are unwound from the panel roller <NUM> and the links <NUM>, <NUM>, and <NUM> move downwards.

Certain embodiments or other embodiments of the disclosure described above are not mutually exclusive or distinct from each other. Any or all elements of the embodiments of the disclosure described above may be combined or combined with each other in configuration or function.

For example, a configuration "A" described in one embodiment of the disclosure and the drawings and a configuration "B" described in another embodiment of the disclosure and the drawings may be combined with each other. Namely, although the combination between the configurations is not directly described, the combination is possible except in the case where it is described that the combination is impossible.

Claim 1:
A display device (<NUM>) comprising:
a flexible display panel (<NUM>);
a frame (<NUM>) adjacent to the display panel (<NUM>);
a panel roller (<NUM>) coupled to the frame (<NUM>), the display panel (<NUM>) being wound around or unwound from the panel roller (<NUM>);
a first foldable link (220a, 230a, 240a) having one end pivotably connected to the frame (<NUM>) and the other end pivotably connected adjacent to a lower side of the display panel (<NUM>) unwound from the panel roller (<NUM>);
a second foldable link (220b, 230b, 240b) having one end pivotably connected to the frame (<NUM>) and the other end pivotably connected adjacent to the lower side of the display panel (<NUM>) unwound from the panel roller (<NUM>), the second foldable link (220b, 230b, 240b) positioned opposite to the first foldable link (220a, 230a, 240a);
a motor (M) mounted to the frame (<NUM>) between the first foldable link (220a, 230a, 240a) and the second foldable link (220b, 230b, 240b);
a first gear box (301a) mounted to the frame (<NUM>) adjacent to the first foldable link (220a, 230a, 240a), the first gear box (301a) having a first link gear (310a) configured to rotate with a pivot shaft of the one end of the first foldable link (220a, 230a, 240a) and a first worm gear (320a) engaged with the first link gear (<NUM>10a);
a second gear box (301b) mounted to the frame (<NUM>) adjacent to the second foldable link (220b, 230b, 240b), the second gear box (301b) having a second link gear (310b) configured to rotate with a pivot shaft of the one end of the second foldable link (220b, 230b, 240b) and a second worm gear (320b) engaged with the second first link gear (310b); and
a driving shaft (343a, 343b) configured to transmit power provided by the motor (M) to the first gear (310a) of the first gear box (301a) and to the second gear (310b) of the second gear box (301b), the first worm gear (320a) and the second worm gear being configured to rotate in a same direction with respect to a rotational direction of the driving shaft (343a, 343b).