KR102262773B1 - Variable display device - Google Patents

Abstract

The present invention relates to a variable display device that can be used variably in a flat mode and a curved mode, and a method for driving the flat mode and curved mode thereof.
A feature of the present invention is to form a plurality of cutting grooves along both edges in the longitudinal direction of the FPCB of the LED assembly, which is the light source of the liquid crystal display of the variable display device.
Through this, even when the variable display device changes to a convex curved mode, a concave curved mode, and a flat plate mode, stress can not be concentrated on the FPCB, thereby preventing the FPCB from being damaged.
Accordingly, it is possible to prevent a problem of lowering the luminance of the variable display device, and it is possible to prevent problems in which the quality of the variable display device is deteriorated, such as deterioration in luminance and image quality.

Description

Variable display device

The present invention relates to a variable display device that can be used variably in a flat mode and a curved mode.

In recent years, as society enters the information age in earnest, the field of display that processes and displays a large amount of information has developed rapidly, and in response to this, various various flat display devices have been developed. Be in the spotlight.

Specific examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescence display. Electroluminescence display device (ELD), organic light emitting diodes (OLED), etc. are mentioned. These flat panel display devices show excellent performance of thinness, light weight, and low power consumption, and thus the conventional cathode ray tube (CRT). : CRT) is rapidly being replaced.

Such a flat panel display device has advantages of high quality, ultra-thin, light weight and large area, has advantages of space utilization, interior and design, and can have various application fields.

And in recent years, flat-panel display devices are rapidly emerging as a next-generation display device as a curved display device that forms a curved surface. can be made to feel comfortable, or to have a wider viewing radius than a flat panel display device.

On the other hand, recently, research on a variable display device that can satisfy all the advantages of a flat display device, improved immersion, and a curved display device having a wide viewing radius has been demanded.

The variable display device operates in a flat-panel mode in order to improve spatial usability, and implements and operates in a curved-surface mode in order to improve immersion or realize a wider viewing radius, thereby taking into account the user's convenience. can

On the other hand, the LED assembly, which is the light source of the backlight unit that supplies light from the variable display device to the liquid crystal panel, is mounted on a PCB made of a metal material. It is a difficult situation to change.

In particular, in the process of changing the variable display device to a flat mode and a curved mode, stress is concentrated on the PCB, which causes damage to the PCB, which leads to a problem in that the quality of the display device is deteriorated. do.

The present invention is to solve the above problems, and a first object is to prevent damage to the LED assembly of the backlight unit in a variable display device that can implement both a flat panel display device and a curved display device. do.

Through this, a second object is to prevent the quality of the variable display device from being deteriorated.

In order to achieve the object as described above, the present invention is a liquid crystal panel; a light guide plate positioned under the liquid crystal panel; A flexible printed circuit board (FPCB) positioned to correspond to the light incident surface of the light guide plate and provided with a plurality of cutting grooves spaced apart from each other at regular intervals along both edges in the longitudinal direction, in which a plurality of LEDs and the plurality of LEDs are mounted. It includes an LED assembly, wherein the FPCB provides a variable display device in which bending occurs in a direction perpendicular to a normal line of a mounting surface on which the plurality of LEDs are mounted.

At this time, the liquid crystal panel and the LED assembly are variable (flat mode) forming a flat surface, a convex curved mode forming a convex or concave curved surface, or a concave curved mode (concave curved mode). variable), the plurality of cutting grooves are formed of first and second inclined surfaces, and the vertices of the plurality of cutting grooves provided on the first edge in the longitudinal direction of the FPCB are provided on the second edge in the longitudinal direction of the FPCB. The vertices of the plurality of cut grooves face each other.

(N은 상수, n은 상기 FPCB의 일 가장자리를 따라 형성된 상기 컷팅홈의 개수, d는 상기 제 1 및 제 2 경사면 사이의 간격, W는 상기 FPCB의 폭, R_θ는

(R은 휨이 발생된 상기 FPCB의 중심부를 기준으로 한 원의 반지름))의 식을 통해 정의되며, 상기 가변형 표시장치가 상기 볼록 곡면형 모드(convex curved mode)일 때, 상기 FPCB는 상기 양측 가장자리가 상기 액정패널을 향해 볼록하게 휜다. And, the sum of the intervals between the first and second inclined surfaces of the plurality of cutting grooves is

(N is a constant, n is the number of the cutting grooves formed along one edge of the FPCB, d is the interval between the first and second inclined surfaces, W is the width of the FPCB, R _θ is

(R is the radius of the circle with respect to the center of the FPCB where the bending occurs)), and when the flexible display device is in the convex curved mode, the FPCB is The edge is convexly curved toward the liquid crystal panel.

In addition, the interval between the first and second inclined surfaces of the plurality of cutting grooves provided on the first edge facing the liquid crystal panel of the FPCB is the first of the plurality of cutting grooves provided on the second edge. and the gap between the second inclined surfaces, and when the variable display device is in the concave curved mode, both edges of the FPCB are concavely curved toward the liquid crystal panel.

At this time, the interval between the first and second inclined surfaces of the plurality of cutting grooves provided on the first edge facing the liquid crystal panel of the FPCB is the first of the plurality of cutting grooves provided on the second edge. and a gap between the second inclined surfaces.

As described above, according to the present invention, by forming a plurality of cutting grooves along both edges in the longitudinal direction of the FPCB of the LED assembly, which is the light source of the liquid crystal display of the variable display device, the variable display device can be configured in a convex curved mode, a concave mode. It is possible to prevent the stress from being concentrated in the FPCB even if it is varied in the curved mode and the flat mode, so there is an effect to prevent the occurrence of damage to the FPCB.

Accordingly, it is possible to prevent a problem in which the luminance of the variable display device is lowered, and there is an effect in that it is possible to prevent a problem in which the quality of the variable display device is deteriorated, such as deterioration in luminance and image quality.

1A to 1C are perspective views schematically illustrating a variable display device according to an embodiment of the present invention;
2 is a perspective view schematically illustrating a liquid crystal display of a variable display device according to an embodiment of the present invention;
3 is a perspective view schematically illustrating an LED assembly of a liquid crystal display of a variable display device according to an embodiment of the present invention;
4a to 4b are plan views schematically showing the bending of the LED assembly of FIG. 3a;

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings.

1A to 1C are perspective views schematically illustrating a variable display device according to an embodiment of the present invention, and FIG. 2 is a perspective view schematically illustrating a liquid crystal display device of the variable display device according to an embodiment of the present invention.

As shown, the variable display device 100 according to the embodiment of the present invention includes a liquid crystal display 110 for realizing a large image, and external cases 160 and 170 for accommodating the liquid crystal display 110 , and , it is connected to the lower end or the rear of the outer case (160, 170) consists of a pedestal 180 formed to be fixed to a desk or wall.

Here, the liquid crystal display device (LCD) 110 is advantageous for displaying moving images and has a large contrast ratio, so that it is actively used in TVs, monitors, and the like.

The liquid crystal display 110 includes a liquid crystal panel 111 that is bonded by interposing a liquid crystal layer between two parallel substrates, and the liquid crystal molecules are arranged by an electric field in the liquid crystal panel 111 . Change the direction to realize the difference in transmittance.

In addition, the liquid crystal panel 111 requires a separate light source to display the difference in transmittance as an image because it does not have a self-luminous element, and for this purpose, a backlight unit having a built-in light source on the rear surface of the liquid crystal panel 111 ( backlight unit: 120) is arranged.

Looking at this in more detail with reference to FIG. 2 , the liquid crystal display 110 is largely composed of a liquid crystal panel 111 and a backlight unit 120 , and the liquid crystal panel 111 plays a key role in image expression. As such, it includes a first substrate 112 and a second substrate 114 bonded to each other with a liquid crystal layer interposed therebetween.

At this time, under the premise of the active matrix method, although not shown in the drawing, a plurality of gate lines and data lines intersect on the inner surface of the first substrate 112 , which is usually called an array substrate, to define a pixel, and at each intersection point, a plurality of gate lines and data lines cross each other. A thin film transistor (TFT) is provided and is connected to a transparent pixel electrode formed in each pixel in a one-to-one correspondence.

In addition, on the inner surface of the second substrate 114 called a color filter substrate, a color filter of red (R), green (G), and blue (B) colors as an example corresponding to each pixel and each color filter are provided. A black matrix is provided to cover non-display elements such as gate lines, data lines, and thin film transistors.

In addition, a transparent common electrode covering each color filter and the black matrix is provided on the inner surface of the second substrate 114 .

In addition, polarizing plates (not shown) that selectively transmit only a specific light are attached to the outer surfaces of the first and second substrates 112 and 114 , respectively.

In addition, along at least one edge of the liquid crystal panel 111, the printed circuit board 118 is connected via a connection member 116 such as a flexible circuit board or a tape carrier package (TCP), so that in the modularization process, the printed circuit board 118 is connected. The liquid crystal panel 111 is properly bent to the rear surface to be in close contact.

Accordingly, in the liquid crystal panel 111 having the above-described structure, when the thin film transistor selected for each gate line is turned on by the on/off signal of the gate driving circuit transmitted by scanning, the signal voltage of the data driving circuit is data It is transmitted to the corresponding pixel electrode through the line, and the arrangement direction of the liquid crystal molecules in the liquid crystal layer is changed by the electric field between the pixel electrode and the common electrode accordingly, indicating a difference in transmittance.

In addition, the liquid crystal display 110 is provided with a backlight unit 120 that supplies light from the rear surface of the liquid crystal panel 111 so that the difference in transmittance is expressed to the outside.

The backlight unit 120 includes the light guide plate 123 , the LED assembly 200 arranged along the longitudinal direction of at least one edge of the light guide plate 123 , the white or silver reflector 125 , and the light guide plate 123 interposed above the light guide plate 123 . and an optical sheet 121 .

The aforementioned LED assembly 200 is a light source of the backlight unit 120 and is located on one side of the light guide plate 123 to face the light incident portion of the light guide plate 123 , and the LED assembly 200 includes a plurality of LEDs. 210 and the LED 210 of the LED FPCB (flexible printed circuit board: 220, hereinafter referred to as FPCB) is mounted spaced apart from each other.

Here, the FPCB 220 of the variable display device 100 according to the embodiment of the present invention has a flexible property, and a plurality of cutting grooves 230 (refer to FIG. 3 ) are provided along both edges in the longitudinal direction at regular intervals. It is characterized in that it is formed spaced apart. Through this, the LED assembly 200 according to the embodiment of the present invention can prevent the FPCB 220 from being damaged when implementing the mode of the variable display device 100 . We will look at this in more detail later.

The light guide plate 123 spreads evenly over a wide area of the light guide plate 123 while the light incident from the LED 210 travels through the light guide plate 123 by total reflection several times to provide a surface light source to the liquid crystal panel 111 .

The light guide plate 123 may include a pattern having a specific shape on the rear surface to supply a uniform surface light source. Here, the pattern may be variously configured such as an elliptical pattern, a polygonal pattern, a hologram pattern, etc. in order to guide the light incident into the light guide plate 123 . The pattern is formed on the lower surface of the light guide plate 123 by a printing method or an injection method.

In addition, the reflection plate 125 is located on the rear surface of the light guide plate 123 , and reflects the light passing through the rear surface of the light guide plate 123 toward the liquid crystal panel 111 to improve the luminance and efficiency of the light.

The optical sheet 121 on the light guide plate 123 includes a diffusion sheet and at least one light collecting sheet. Here, the diffusion sheet is located directly above the light guide plate 123 , and serves to adjust the direction of light so that the light travels toward the light collecting sheet while dispersing the light incident through the light guide plate 123 .

Then, the light diffused through the diffusion sheet is condensed in the liquid crystal panel 111 direction by the light collecting sheet. Accordingly, most of the light passing through the light collecting sheet proceeds perpendicular to the liquid crystal panel 111 .

The liquid crystal panel 111 and the backlight unit 120 are integrally modularized through the guide panel 130 , the case top 140 , and the cover bottom 150 to form the liquid crystal display device 110 , the case top 140 . ) is made of a rectangular frame shape in which a cross section is bent in a “L” shape to cover the upper surface and side edges of the liquid crystal panel 111 , and the image implemented in the liquid crystal panel 111 is displayed by opening the front of the case top 140 . configured to display.

The guide panel 130 supports the edge of the liquid crystal panel 111 and has a rectangular frame shape to surround the edge of the backlight unit 120, and the liquid crystal panel ( 111 ) and a horizontal part for separating the positions of the backlight unit 120 are provided.

And, this guide panel 130 is seated on the cover bottom 150, the cover bottom 150 provides a horizontal surface on which the backlight unit 120, including the liquid crystal panel 111, is mounted to the liquid crystal display device 110. It serves as a lower frame that supports the whole and minimizes light loss at the same time, and the edge of the horizontal plane is vertically bent to form the edge of the cover bottom 150 .

The guide panel 130 , the cover bottom 150 , and the case top 140 cover the upper surface edge of the liquid crystal panel 111 with the guide panel 130 surrounding the edges of the liquid crystal panel 111 and the backlight unit 120 . The case top 140 and the cover bottom 150 covering the back surface of the backlight unit 120 are coupled from the front and rear, respectively, to be integrated into a module through the guide panel 130 .

At this time, the case top 140 is also referred to as a top cover or a top case, the guide panel 130 is also referred to as a support main or main support, a mold frame, and the cover bottom 150 is also referred to as a bottom cover or a lower cover. also lose

In this case, in the liquid crystal display 110 having the above-described structure, the case top 140 and the cover bottom 150 may be omitted in order to realize a light and thin liquid crystal display that has been recently requested. By removing the case top 140 and the cover bottom 150, the liquid crystal display 110 can be made lightweight and thin, and has the effect of simplifying the process.

In addition, due to the deletion of the case top 140 and the cover bottom 150 made of a metal material, it is possible to reduce the process cost.

The modular liquid crystal display 110 is finally modularized through the front cover 160 and the rear cover 170 that are the exterior cases, thereby forming the variable display device 100 .

As shown in FIG. 1A , the variable display device 100 according to the embodiment of the present invention allows the liquid crystal display device 110 on which an image is to be realized to operate in a flat mode formed of a flat plate type. A concave curved mode in which the liquid crystal display 110 in which an image is implemented as shown in FIG. 1B has a concavely curved curved surface with respect to the front of the liquid crystal display 110 to improve usability ( concave curved mode), the viewer's level of immersion is improved and the image is more realistic, so that the user can feel comfortable.

In addition, as shown in FIG. 1C , the liquid crystal display 110 on which an image is realized has a convex curved mode with a curved portion convexly curved with respect to the front of the liquid crystal display 110 . ), it has a wide viewing radius and delivers news, advertisements, and the like by images implemented in the liquid crystal panel 110 to many viewers.

That is, the variable display device 100 of the present invention can selectively vary between the flat panel mode and the convex curved mode or the concave curved mode, so that the user can display the flat panel mode and the curved mode as needed. Since it can be selected and used as a device, the user's convenience can be considered.

In particular, the variable display device 100 according to the embodiment of the present invention includes a plurality of LEDs 210 of the LED assembly 200, which are the light sources of the backlight unit 120 of the liquid crystal display 110, FPCB ( 220) and spaced apart from each other to form a plurality of cutting grooves 230 (refer to FIG. 3) spaced apart along both edges of the FPCB 220 in the longitudinal direction at regular intervals to form the variable display device 100. Even if the convex curved mode, the concave curved mode, and the flat mode are varied, it is possible to prevent the stress from being concentrated in the FPCB 220 , thereby preventing the FPCB 220 from being damaged.

Through this, it is possible to prevent a problem of lowering the luminance of the variable display device 100 from occurring, and it is possible to prevent problems in which the quality of the variable display device 100 deteriorates, such as deterioration of luminance and image quality. .

3 is a perspective view schematically illustrating an LED assembly of a liquid crystal display of a variable display device according to an embodiment of the present invention, and FIGS. 4A to 4B are plan views schematically illustrating bending of the LED assembly of FIG. 3A.

As shown in FIG. 3 , the LED assembly 200 includes a plurality of LEDs 210 , and a plurality of LEDs 210 are spaced apart from each other by a predetermined interval, and the FPCB 220 mounted by surface mount technology (SMT). ) is included.

This LED assembly 200 is fixed using a screw (not shown) to the inside of the edge of the cover bottom (150 in FIG. 2), or the position is fixed through an adhesive tape (not shown) or a fixing clip (not shown). , so that the light emitted from the plurality of LEDs 210 faces the light incident surface of the light guide plate (123 in FIG. 2 ).

In this case, when a fixing clip (not shown) is used, grooves (not shown) for the fixing clip may be provided along both edges of the FPCB 220 .

A plurality of LEDs 210 emit light having colors of red (R), green (G), and blue (B), respectively, and by turning on these plurality of RGB LEDs 210 at once, white light by color mixing can be realized. have.

Alternatively, by using the LED 210 configured with an LED chip (not shown) that emits all RGB colors, white light may be implemented in each LED 210, or the LED 210 including a chip emitting white. It is also possible to implement each of the complete white light.

In this case, the plurality of LEDs 210 use a blue LED 210 including a blue LED chip having excellent luminous efficiency and luminance to improve luminous efficiency and luminance, and 'cerium-doped yttrium aluminum garnet (YAG) as a phosphor. :Ce)', that is, a blue LED 210 made of a yellow phosphor may be used.

The blue light emitted from the blue LED 210 passes through the phosphor and is mixed with the yellow light emitted by the phosphor to realize white light.

Here, the FPCB 220 includes a base film having flexible characteristics, a power wiring layer including a plurality of metal wirings formed by patterning a conductive material on the base film, and a cover layer.

The base film serves to support the power wiring layer and the plurality of LEDs 210 by mounting them as an upper layer.

The base film is made in the form of a film by accommodating a resin-based material including polyimide or polyester. Alternatively, it may be made of a material having thermal conductivity such as FR4 (flame resistant 4) and T-preg.

In addition, a cover layer as an organic or inorganic insulating material for protecting the power wiring layer is formed on the upper portion of the power wiring layer, except for a portion where a plurality of metal wirings are formed.

A plurality of LEDs 210 mounted on the FPCB 220 are respectively connected in series or parallel through the metal wiring of the power wiring layer to receive power.

Here, in the LED assembly 200 according to the embodiment of the present invention, a plurality of cutting grooves 230 are formed at both edges of the FPCB 220 in the longitudinal direction at regular intervals.

Each of the plurality of cutting grooves 230 is formed of first and second inclined surfaces 230a and 230b inclined at a predetermined angle, and the plurality of cutting grooves 230 are formed along both edges in the longitudinal direction of the FPCB 220 . The longitudinal direction of the FPCB 220 so that the vertices formed by the first and second inclined surfaces 230a and 230b face the vertices formed by the first and second inclined surfaces 230a and 230b of the cutting groove 230 formed at the opposite edge thereof. formed along both edges of

At this time, the sum of the spacing d between the first and second inclined surfaces 230a and 230b of the plurality of cutting grooves 230 formed along one edge of the FPCB 220 is formed according to the following [Equation 1]. It is preferable to be

[Formula 1]

Here, N is a constant, n is the number of cutting grooves 230 formed along one edge of the FPCB 220 , and d is an interval (d) between the first and second inclined surfaces 230a and 230b of the cutting groove 230 . ) is indicated.

The spacing d between the first and second inclined surfaces 230a and 230b of the plurality of cutting grooves 230 may be defined according to Equation 2 below.

[Formula 2]

Here, W represents the width of the FPCB (230).

_{And, R θ} is defined through [Equation 3] below, where R in [Equation 3] represents the radius of the circle based on the center of the FPCB 220 in which the bending occurs.

[Equation 3]

이므로,

이다. As an example, if the length is 1205mm and the FPCB 220 having a width of 10mm is to be bent to 5000R,

Because of,

to be.

이고,

이므로, And,

ego,

Because of,

가 된다.

becomes

That is, when the length of the FPCB 220 is 1205 mm and the width W is 10 mm, in order to generate the bending of the FPCB 220 to have 5000R, a plurality of cutting grooves formed along one edge of the FPCB 220 ( The sum of the spacing d between the first and second inclined surfaces 230a and 230b of 230 should be 1.205 mm or more.

Accordingly, the LED assembly 200 is a thread in which a plurality of LEDs 210 of the FPCB 220 are mounted in the planar left and right directions of the FPCB 220 through the cutting groove 230 together with the flexible nature of the FPCB 220 . It is possible to implement the bending of the FPCB 220 in a direction perpendicular to the normal of the mounting surface based on the scene. (+X, -X axis directions defined in the drawing)

Through this, in the LED assembly 200 of the present invention, stress is applied to the FPCB 220 of the LED assembly 200 in the process in which the variable display device (100 in FIG. 2) is changed to a flat mode and a concave or convex curved mode. It is possible to prevent the occurrence of damage to the FPCB 220 because it is not concentrated.

That is, as shown in Figure 4a, the LED assembly 200 may generate a bending in the +X-axis direction defined in the drawing by both ends of the longitudinal direction of the FPCB 220 in the plan view, at this time the FPCB 220 is the FPCB Both edges in the longitudinal direction of 220 are concave toward the +X-axis direction.

Here, if the interval d between the first and second inclined surfaces 230a and 230b of the plurality of cutting grooves 230 in which no bending occurs is defined as the first interval, both sides in the longitudinal direction of the FPCB 220 as described above. When the edge is formed to be concave toward the +X-axis direction, the first and second inclined surfaces 230a of the plurality of cutting grooves 230 formed along the first edge 220a toward the +X-axis direction of the FPCB 220; 230b) is reduced to a second interval d1 that is narrower than the first interval d.

And, the interval between the first and second inclined surfaces 230a and 230b of the plurality of cutting grooves 230 formed along the second edge 220b facing the -X-axis direction of the FPCB 220 is a first interval d ) is widened by the third interval d2 wider than that.

That is, the FPCB 220 is formed so that the radius of curvature of the first edge 220a is narrower than the radius of curvature of the second edge 220b, the FPCB 220 has both edges in the longitudinal direction of the FPCB 220 +X Deflection may occur concavely in the axial direction.

In addition, as shown in Fig. 4b, when both ends of the longitudinal direction of the FPCB 220 generate bending in the -X-axis direction defined in the drawing, the FPCB 220 is both sides of the FPCB 220 in the longitudinal direction. The edge is formed convex toward the +X-axis direction.

At this time, the interval between the first and second inclined surfaces 230a and 230b of the plurality of cutting grooves 230 formed along the first edge 220a facing the +X-axis direction of the FPCB 220 is a first interval d ), the first and second inclined surfaces of the plurality of cutting grooves 230 formed along the second edge 220b facing the -X-axis direction of the FPCB 220 and formed to have a fourth interval d3 wider than The gap between 230a and 230b is formed to have a fifth gap d4 that is narrower than the first gap d.

Accordingly, the FPCB 220 is formed so that the radius of curvature of the first edge 220a is wider than the radius of curvature of the second edge 220b, the FPCB 220 has both edges in the longitudinal direction of the FPCB 220 +X A warp can be generated convexly in the axial direction.

As such, the FPCB 220 of the LED assembly 200 according to the embodiment of the present invention is a plurality of the FPCB 220 through a plurality of cutting grooves 230 formed along the longitudinal direction with the flexible nature of the FPCB 220. It is possible to implement the bending of the FPCB 220 in a direction perpendicular to the normal of the mounting surface around the mounting surface on which the LED 210 is mounted, so that the variable display device ( 100 in FIG. 2 ) is a flat-panel mode and a concave or convex curved surface type. In the process of changing the mode, stress is not concentrated on the FPCB 220 of the LED assembly 200, so that damage to the FPCB 220 can be prevented.

That is, the variable display device ( 100 in FIG. 2 ) is curved with respect to the front of the liquid crystal display device ( 110 in FIG. 2 ) in a flat panel mode in which the liquid crystal display device ( 110 in FIG. 2 ) is a flat plate type. When variable to a concave curved mode having a curved surface, the FPCB 220 of the LED assembly 200 is bent so that the radius of curvature of one edge facing the liquid crystal panel (111 in FIG. 2) is narrower than the radius of curvature of the opposite edge. will occur

In addition, when the variable display device (100 in FIG. 2) is changed to a convex curved mode having a convexly curved curved portion with respect to the front of the liquid crystal display device (110 in FIG. 2), the LED assembly 200 The FPCB 220 is bent so that the radius of curvature of one edge facing the liquid crystal panel (111 in FIG. 2) is wider than the radius of curvature of the opposite edge.

At this time, even if the bending of the FPCB 220 occurs, the stress due to the bending is not concentrated in the FPCB 220 , and thus it is possible to prevent the occurrence of damage to the FPCB 220 .

In other words, in a typical LED assembly, stress is concentrated on both edges of the FPCB while the variable display device is changed from the flat-panel mode to the concave or convex curved mode, and the FPCB shrinks due to this stress. .

Such a phenomenon of the FPCB may cause damage to the FPCB or change the optical distance between a plurality of LEDs mounted on the FPCB and the light incident surface of the light guide plate, thereby lowering the luminance of the variable display device.

This leads to deterioration of the quality of the variable display device such as deterioration in luminance and image quality.

In contrast, in the LED assembly 200 according to the embodiment of the present invention, a plurality of cutting grooves 230 are formed along both edges of the FPCB 220 in the longitudinal direction, so that the variable display device (100 in FIG. 2 ) is a flat panel type. In the process of changing from the mode to the concave or convex curved mode, the stress concentrated on both edges of the FPCB 220 is offset by the cutting groove 230, so that the stress is not concentrated.

Accordingly, the FPCB 220 does not move, and through this, the FPCB 220 is not damaged, and a plurality of LEDs 210 and a light guide plate (123 in FIG. 2 ) mounted on the FPCB 220 do not occur. The optical distance between the light incident surfaces is also not changed, so that the luminance of the variable display device ( 100 in FIG. 2 ) is not lowered.

Accordingly, the luminance and image quality of the variable display device 100 in FIG. 2 according to the embodiment of the present invention are improved.

As described above, in the variable display device ( 100 in FIG. 2 ) according to the embodiment of the present invention, both edges in the longitudinal direction of the FPCB 220 of the LED assembly 200 that is the light source of the liquid crystal display ( 110 in FIG. 2 ) By forming a plurality of cutting grooves 230 along This can prevent damage to the FPCB 220 from occurring.

Through this, it is possible to prevent a problem of lowering the luminance of the variable display device ( 100 in FIG. 2 ) from occurring, and a problem in which the quality of the variable display device ( 100 in FIG. 2 ) is deteriorated such as deterioration in luminance and image quality occurs. can be prevented from doing

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

200: LED assembly
210: LED
220: FPCB
230: cutting grooves (230a, 230b: first and second inclined surfaces)

Claims (8)

a liquid crystal panel;
a light guide plate positioned under the liquid crystal panel;
A flexible printed circuit board (FPCB) positioned to correspond to the light incident surface of the light guide plate, on which a plurality of LEDs and the plurality of LEDs are mounted, and spaced apart from each other at regular intervals along both edges in the longitudinal direction to include a plurality of cutting grooves. LED assembly
Including, the FPCB is bent in a direction perpendicular to the normal of the mounting surface on which the plurality of LEDs are mounted,
The cutting groove and the LED assembly are arranged perpendicular to the plane of the liquid crystal panel.
The method of claim 1,
The liquid crystal panel and the LED assembly are variable in a flat mode forming a plane, a convex curved mode forming a convex or concave curved surface, or a concave curved mode variable display device.
The method of claim 1,
The plurality of cutting grooves are formed of first and second inclined surfaces, and vertices of the plurality of cutting grooves provided at the first edge in the longitudinal direction of the FPCB are the plurality of cutting grooves provided at the second edge in the longitudinal direction of the FPCB. A variable display device in which the vertices of the grooves face each other.
4. The method of claim 3,
The sum of the intervals between the first and second inclined surfaces of the plurality of cutting grooves is

(N is a constant, n is the number of the cutting grooves formed along one edge of the FPCB, d is the interval between the first and second inclined surfaces, W is the width of the FPCB, R _θ is

(R is the radius of the circle with respect to the center of the FPCB where the warpage has occurred) A variable display device defined through the formula.
3. The method of claim 2,
When the variable display device is in the convex curved mode,
The FPCB is a variable display device in which both edges of the central portion in the longitudinal direction are convexly curved toward the liquid crystal panel.
6. The method of claim 5,
A distance between the first and second inclined surfaces of the plurality of cutting grooves provided on the first edge facing the liquid crystal panel of the FPCB is the first and second of the plurality of cutting grooves provided on the second edge. 2 Variable display device wider than the gap between slopes.
3. The method of claim 2,
When the variable display device is in the concave curved mode,
The FPCB is a variable display device in which both edges of the central portion in the longitudinal direction are concavely curved toward the liquid crystal panel.
8. The method of claim 7,
A distance between the first and second inclined surfaces of the plurality of cutting grooves provided on the first edge facing the liquid crystal panel of the FPCB is the first and second of the plurality of cutting grooves provided on the second edge. 2 Variable display device narrower than the gap between slopes.

Images