KR102428240B1 - Curved liquid Crystal Display device - Google Patents

Abstract

The present invention relates to a curved liquid crystal display, and more particularly, to a curved liquid crystal display including a curved backlight unit that realizes an optimal effect in the curved liquid crystal display.
A feature of the present invention is that the pyramid pattern provided on the lower surface of the light guide plate of the curved backlight unit is formed to have a variable interval in the longitudinal direction from the light incident surface perpendicular to the longitudinal direction of the light guide plate to the incoming light surface. Therefore, the emission efficiency can be further improved and more uniform light can be emitted.
Accordingly, according to the present invention, it is possible to prevent deterioration of screen quality due to uneven luminance of the curved liquid crystal display device.

Description

Curved liquid crystal display device

The present invention relates to a curved liquid crystal display, and more particularly, to a curved liquid crystal display including a curved backlight unit that realizes an optimal effect in the curved liquid crystal display.

Recently, as society enters the information age in earnest, interest in information displays that process and display a large amount of information is heightened, and as the demand to use portable information media increases, the display field has developed rapidly. In response to this, various light and thin display devices have been developed and are in the spotlight.

Specific examples of such a display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), an electroluminescence display device ( Electroluminescence Display device (ELD), organic light emitting diodes (OLED), etc. are mentioned. These display devices show excellent performance of thinness, light weight, and low power consumption, so that the existing cathode ray tube (CRT) can be used. are being replaced quickly.

In addition, as shown in FIG. 1 , a curved liquid crystal display (LCD: 10) in which a liquid crystal display has a curved surface is rapidly emerging as a next-generation display device. can be improved and the image can also be made more realistic, so that the user can feel comfortable.

The curved liquid crystal display device 10 requires a separate light source to display the difference in transmittance as an image because the liquid crystal panel does not have a self-luminous element. A backlight unit is arranged.

The backlight unit includes an LED assembly including LEDs arranged along the longitudinal direction of one edge and an LED printed circuit board (hereinafter referred to as a PCB) on which the LEDs are mounted, a white or silver reflector, and a light guide plate mounted on the reflector. and an optical sheet interposed thereon.

On the other hand, fine patterns are formed on the lower surface of the light guide plate to supply a uniform surface light source, and the patterns provided on the light guide plate are designed to be optimized for general flat panel liquid crystal display devices, such as the size of the patterns and the spacing between the patterns.

Accordingly, when such a light guide plate is intended to be used in the curved liquid crystal display 10, there is a problem in that luminance non-uniformity occurs at a specific position of the liquid crystal display to which the curvature is applied, resulting in a defect in which screen quality is deteriorated.

Accordingly, there is a demand for a curved backlight unit suitable for the curved liquid crystal display 10 .

SUMMARY OF THE INVENTION The present invention is to solve the above problems, and a first object is to provide a curved backlight unit having optimal conditions suitable for a curved liquid crystal display device.

Through this, it is a second object to prevent deterioration of screen quality due to uneven luminance of the curved liquid crystal display device.

In order to achieve the object as described above, the present invention provides a reflective plate and a pyramid pattern, which is seated on the reflective plate and has a variable interval between the reflective plate and the lower surface in the longitudinal direction from the light incident surface to the incoming light surface. a light guide plate, an LED assembly arranged along the light incident surface of the light guide plate, an optical sheet seated on the light guide plate, and a curved liquid crystal panel seated on the optical sheet, wherein the pyramid pattern is formed from the light incident surface They are arranged adjacent to each other so as to have a first interval in the light incident portion adjacent to the light incident surface in the longitudinal direction toward the incoming light surface, and are arranged adjacent to each other to have a second interval narrower than the first interval in the light incoming portion adjacent to the incoming light surface. and, as the radius of curvature of the light guide plate increases, the aspect ratio (= the first interval/the second interval) between the first interval and the second interval decreases.

At this time, the interval between the first and the second interval between the

(

)

)

= 도광판 곡면(휨) 각도, v = 입광부 기준 하부면에 위치하는 피라미드 패턴이 있는 도광판의 위치, L = 도광판의 입광면에서 반입광면까지의 길이,

= (L'/L)(L': 적용된 도광판의 입광면에서 반입광면까지의 길이, L = 표준 도광판의 입광면에서 반입광면까지의 길이),

= 도광판의 길이방향(H)에서의 등간격 패턴 간격,

= 도광판의 입광면에서 반입광면까지의 길이방향(V)에서 등간격 패턴 간격,

= 도광판의 굴절율에 따른 패턴 간격 변화율 상수,

= 도광판의 굴절율에 따른 패턴 변화율 상수를 의미하며, 상기 도광판의 곡면(휨) 각도는 0 ≤

≤ π(rad) 범위 내에 위치하며, 상기

와 상기

은 1.5(w)(w = 피라미드 패턴의 하면의 너비)에 비해 크다. is defined through

= the angle of the curved surface (bending) of the light guide plate, v = the position of the light guide plate with the pyramid pattern located on the lower surface of the light incident part reference, L = the length from the light incident surface to the incoming light surface of the light guide plate,

= (L'/L)(L': the length from the light incident surface to the incoming light surface of the applied light guide plate, L = the length from the light incident surface to the incoming light surface of the standard light guide plate),

= equally spaced pattern spacing in the longitudinal direction (H) of the light guide plate,

= equally spaced pattern spacing in the longitudinal direction (V) from the light incident face to the incoming light face of the light guide plate,

= constant rate of change of pattern spacing according to the refractive index of the light guide plate,

= means the pattern change rate constant according to the refractive index of the light guide plate, and the angle of the curved surface (bending) of the light guide plate is 0 ≤

≤ π (rad) located within the range, the

and above

is larger than 1.5(w) (w = the width of the lower surface of the pyramid pattern).

In this case, the pyramid patterns are arranged adjacent to each other so as to have equal intervals in the longitudinal direction of the light guide plate, and the pyramid pattern is formed in an engraved shape from the lower surface, has a square lower surface and one extending from the edge of the lower surface, respectively. and four side surfaces constituting the corners of , and the height of the pyramid pattern is 1/2 of the width corresponding to one length of the lower surface.

)가 0도일 때, 상기 제 1 사이간격은 0.37mm이며, 상기 제 2 사이간격은 0.063mm이며, 상기 도광판 곡면(휨) 각도(

)가 20도일 때, 상기 제 1 사이간격은 0.32mm이며, 상기 제 2 사이간격은 0.08mm로, 상기 도광판 곡면(휨) 각도(

)가 커질수록 상기 제 1 사이간격은 줄어들며, 상기 제 2 사이간격은 늘어나며, 상기 곡면형 액정패널은 화상이 구현되는 전방을 향해 오목하게 만곡되며, 상기 도광판과 상기 반사판 그리고 상기 광학시트는 상기 곡면형 액정패널이 위치하는 전방을 향해 오목하게 만곡된다. And, the angle of the curved surface (bending) of the light guide plate (

) is 0 degrees, the first interval is 0.37 mm, the second interval is 0.063 mm, and the light guide plate curved surface (bending) angle (

) is 20 degrees, the first interval is 0.32 mm, the second interval is 0.08 mm, the curved surface (bending) angle of the light guide plate (

) increases, the first interval decreases, the second interval increases, the curved liquid crystal panel is curved concavely toward the front in which an image is realized, and the light guide plate, the reflection plate, and the optical sheet have the curved surface It is curved concavely toward the front where the liquid crystal panel is located.

In addition, a curved guide panel that surrounds the edge of the curved liquid crystal panel, a curved cover bottom configured to be in close contact with the curved guide panel, and the curved guide panel and the curved guide panel around the edge of the curved liquid crystal panel and a curved top cover assembled and coupled to a cover bottom, wherein the curved guide panel, the cover bottom, and the curved top cover are bent to have a curvature corresponding to the curvature of the curved liquid crystal panel.

As described above, according to the present invention, the pyramid pattern provided on the lower surface of the light guide plate of the curved backlight unit is formed to have a variable interval in the longitudinal direction from the light incident surface perpendicular to the longitudinal direction of the light guide plate to the incoming light surface. In the type liquid crystal display device, there is an effect that the emission efficiency can be further improved and the light can be emitted more uniformly.

Through this, the present invention has an effect of preventing the screen quality from being deteriorated due to non-uniform luminance of the curved liquid crystal display device.

1 is a perspective view schematically illustrating a general curved liquid crystal display device.
2 is an exploded perspective view schematically illustrating a curved liquid crystal display according to an embodiment of the present invention;
3 is a perspective view schematically illustrating a curved backlight according to an embodiment of the present invention;
4 is a rear perspective view schematically illustrating the light guide plate of FIG. 3 ;
5 is a perspective view schematically illustrating a pyramid pattern;
6A is an experimental result of measuring a process in which light incident into the light guide plate is totally reflected by the dome pattern in a flat panel liquid crystal display having a dome pattern on the rear surface of the light guide plate;
6B is an experimental result of measuring a process in which light incident into the light guide plate is totally reflected by the dome pattern in a curved liquid crystal display device having a dome pattern on the rear surface of the light guide plate;
6C is an experimental result of measuring a process in which light incident into the light guide plate is totally reflected by the pyramid pattern in a flat panel liquid crystal display having a pyramid pattern on the rear surface of the light guide plate;
6D is an experimental result of measuring a process in which light incident into the light guide plate is totally reflected by the pyramid pattern in a curved liquid crystal display device having a pyramid pattern on the rear surface of the light guide plate;
7A is an experimental result of measuring an illuminance profile of a flat panel liquid crystal display device when all pyramid patterns provided on the lower surface of the light guide plate are arranged with the same spacing.
7B is an experimental result of measuring the illuminance profile of a flat panel liquid crystal display in which the pyramid pattern provided on the lower surface of the light guide plate is formed at a lower density per unit area as it approaches the LED assembly and at a higher density as it moves away from the LED assembly.

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

2 is an exploded perspective view schematically illustrating a curved liquid crystal display according to an embodiment of the present invention.

As illustrated, the curved liquid crystal display 100 includes a curved liquid crystal panel 110 and a curved backlight unit 120 , and a curved guide panel for modularizing the liquid crystal panel 110 and the backlight unit 120 . 130 , a curved cover bottom 150 , and a curved top cover 140 .

At this time, if the direction in the drawing is defined for convenience of explanation, the curved backlight unit 120 is positioned to the rear of the curved liquid crystal panel 110 on the premise that the display surface of the curved liquid crystal panel 110 faces forward. and a curved guide panel 130 having a rectangular frame around their outer circumference, a curved top cover 140 is positioned in front of the curved liquid crystal panel 110, and the curved back light unit 120 is A curved cover bottom 150 is positioned on the rear surface, and is integrated in the front and rear.

Let's take a closer look at each of these.

First, the curved liquid crystal panel 110 is a part that plays a key role in image expression, and includes first and second substrates 112 and 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 clearly 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 a lower substrate or an array substrate, so that a pixel is defined. A thin film transistor (TFT) is provided at each intersection and is connected to the transparent pixel electrode formed in each pixel in a one-to-one correspondence.

And on the inner surface of the second substrate 114 called an upper substrate or a color filter substrate, red (R), green (G), and blue (B) color filters as an example corresponding to each pixel, and these A black matrix is provided around each of the gate lines, data lines, and non-display elements such as thin film transistors. In addition, a transparent common electrode covering them is provided.

At least along one edge of the curved liquid crystal panel 110, the printed circuit board 117 is connected via a connecting member 116 such as a flexible circuit board to the back of the curved cover bottom 150 in the modularization process. bend over and stick

In addition, although not clearly shown in the drawing, upper and lower alignment layers (not shown) for determining the initial molecular arrangement direction of liquid crystals are formed at the boundary between the two substrates 112 and 114 of the curved liquid crystal panel 110 and the liquid crystal layer. A seal pattern is formed along the edges of both substrates 112 and 114 in order to prevent leakage of the liquid crystal layer filled therebetween.

In this case, upper and lower polarizing plates (not shown) are respectively attached to the outer surfaces of the first and second substrates 112 and 114 .

The curved liquid crystal panel 110 is configured to have a certain curvature, and has a curved portion concavely curved with respect to the front of the curved liquid crystal panel 110 on which an image is realized.

In addition, a curved backlight unit 120 for supplying light is provided on a rear surface of the curved liquid crystal panel 110 so that a difference in transmittance indicated by the curved liquid crystal panel 110 is expressed to the outside.

The curved backlight unit 120 includes an LED assembly 129 arranged along the longitudinal direction of at least one edge of the curved guide panel 130 , a white or silver reflector 125 , and is seated on the reflector 125 . and a light guide plate 200 that is used, and an optical sheet 121 interposed thereon.

The aforementioned LED assembly 129 is a light source of the curved backlight unit 120 , and is located on one side of the light guide plate 200 to face the light incident surface 201a of the light guide plate 200 . A plurality of LEDs 129a and a plurality of LEDs 129a include a PCB 129b mounted with a predetermined interval therebetween.

The light guide plate 200 to which the light emitted from the plurality of LEDs 129a of the LED assembly 129 is incident is the light guide plate 200 while the light incident from the LEDs 129a travels through the light guide plate 200 by total reflection several times. ) evenly spread over a wide area to provide a surface light source to the curved liquid crystal panel 110 .

The light guide plate 200 includes a pattern 210 having a specific shape on its lower surface to supply a uniform surface light source. In particular, the pattern 210 included in the light guide plate 200 of the present invention is a curved liquid crystal display device. (100) is characterized in that it is formed to have a specific interval to implement the optimal effect. We will look at this in more detail later.

The reflection plate 125 is located on the rear surface of the light guide plate 200 , and reflects the light passing through the rear surface of the light guide plate 200 toward the curved liquid crystal panel 110 to improve the luminance of the light.

The optical sheet 121 positioned above the light guide plate 200 diffuses or condenses the light passing through the light guide plate 200 .

Therefore, the light emitted from the plurality of LEDs 129a of the LED assembly 129 is processed into uniform high-quality light in the process of sequentially passing through the optical sheet, and then a more uniform surface light source is provided to the curved liquid crystal panel 110 . to be admitted

Using this, the curved liquid crystal panel 110 displays a high-brightness image to the outside.

The curved backlight unit is configured such that the light guide plate, the reflector plate, and the optical sheet are all bent to have a curvature corresponding to the curvature of the curved liquid crystal panel 110 .

The above-described curved liquid crystal panel 110 and curved backlight unit 120 are modularized through the curved guide panel 130 , the curved cover bottom 150 , and the curved top cover 140 .

The curved top cover 140 is formed in a rectangular frame shape with a cross-section bent in a “L” shape to cover the upper surface and side edges of the curved liquid crystal panel 110 , and the front is opened in the curved liquid crystal panel 110 . and display the implemented image.

The curved top cover 140 is curved to have a curvature corresponding to the curvature of the curved liquid crystal panel 110 .

The curved guide panel 130 supports the edge of the curved liquid crystal panel 110 and includes an optical sheet 121 and has a rectangular frame shape to surround the edge of the curved backlight unit 120 .

The curved guide panel 130 surrounds the side surface of the curved backlight unit 120 , and there is a protrusion 131 that separates the positions of the curved liquid crystal panel 110 and the curved backlight unit 120 inside. provided

The curved liquid crystal panel 110 is attached and fixed on the protrusion 131 through an adhesive pad (not shown) such as a double-sided tape.

In addition, the curved liquid crystal panel 110 and the curved backlight unit 120 are seated and the curved cover bottom 150, which is the basis for assembling the entire structure of the curved liquid crystal display 100, has a horizontal surface and a vertical edge thereof. It consists of curved edges.

The curved guide panel 130 and the curved cover bottom 150 are also bent to have a curvature corresponding to the curvature of the curved liquid crystal panel 110 .

The curved guide panel 130 , the curved cover bottom 150 , and the curved top cover 140 form the edges of the curved liquid crystal panel 110 and the curved backlight unit 120 to the curved guide panel 130 . ), the curved top cover 140 surrounding the upper and side edges of the curved liquid crystal panel 110 and the curved cover bottom 150 covering the rear surface of the curved backlight unit 120 are combined in front and rear, respectively. to be integrated and modularized.

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

Here, the curved liquid crystal display 100 according to the embodiment of the present invention is a lower surface 201d (refer to FIG. 4 ) of the light guide plate 200 of the curved backlight unit 120 to the curved liquid crystal display 100 . It is characterized in that the pattern 210 having a specific interval is formed so as to have an optimal condition to fit.

Through this, according to the present invention, it is possible to prevent the screen quality from being deteriorated due to non-uniform luminance of the curved liquid crystal display 100 .

3 is a perspective view schematically illustrating a curved backlight according to an embodiment of the present invention, FIG. 4 is a rear perspective view schematically illustrating the light guide plate of FIG. 3, and FIG. 5 is a perspective view schematically illustrating a pyramid pattern.

6A is an experimental result of measuring a process in which light incident into the light guide plate is totally reflected by the dome pattern in a flat panel liquid crystal display having a dome pattern on the rear surface of the light guide plate, and FIG. This is an experimental result of measuring a process in which light incident into the light guide plate is totally reflected by the dome pattern in a curved liquid crystal display having a pattern.

6C is an experimental result of measuring the total reflection of light incident into the light guide plate by the pyramid pattern in a flat liquid crystal display device having a pyramid pattern on the rear surface of the light guide plate, and FIG. 6D is a pyramid pattern on the rear surface of the light guide plate This is an experimental result of measuring a process in which the light incident into the light guide plate is totally reflected by the pyramid pattern in the provided curved liquid crystal display device.

7A is an experimental result of measuring the illuminance profile of a flat panel liquid crystal display when all pyramid patterns provided on the lower surface of the light guide plate are arranged with the same spacing, and FIG. 7B is a pyramid pattern provided on the lower surface of the light guide plate. This is an experimental result of measuring the illuminance profile of a flat panel liquid crystal display, which is formed at a lower density per unit area as it approaches the LED assembly and at a higher density as it moves away from the LED assembly.

As shown in FIG. 3 , the curved backlight unit 120 according to the embodiment of the present invention includes a white or silver reflective plate 125 seated on a curved cover bottom ( 150 in FIG. 2 ), and one edge thereof. It consists of an LED assembly 129 which is a light source arranged in the longitudinal direction, a light guide plate 200 seated on the reflection plate 125 , and an optical sheet 121 positioned above the light guide plate 200 .

The LED assembly 129 is positioned on one side of the light guide plate 200 to face the light incident surface 201a of the light guide plate 200, and the LED assembly 129 includes a plurality of LEDs 129a and a plurality of LEDs 129a. includes a PCB (129b) mounted to be spaced apart from each other by a predetermined interval.

At this time, the plurality of LEDs 129a emit light having red (R), green (G), and blue (B) colors in a forward direction toward the light incident surface 201a of the light guide plate 200 , and the plurality of RGB By turning on the LEDs 129a all at once, it is possible to realize white light by color mixing.

In particular, recently, in order to improve luminous efficiency and luminance, a blue LED 129a including a blue LED chip having excellent luminous efficiency and luminance is used, and as a phosphor, 'cerium-doped yttrium aluminum garnet (YAG:Ce)', That is, the blue LED 129a made of a yellow phosphor is used.

The blue light emitted from the LED 129a passes through the phosphor and mixes with the yellow light emitted by the phosphor, thereby realizing white light.

In addition to the LED assembly 129 , a fluorescent lamp such as a cold cathode fluorescent lamp or an external electrode fluorescent lamp may be used.

The light guide plate 200 on which the light emitted from the plurality of LEDs 129a is incident is spread evenly over a wide area of the light guide plate 200 while the light incident from the LEDs 129a travels through the light guide plate 200 by total reflection several times. A surface light source is provided to the curved liquid crystal panel (110 in FIG. 2).

Accordingly, the light guide plate 200 is made of a plastic material such as polymethylmethacrylate (PMMA), which is an acrylic transparent resin, which is one of the transmissive materials that can transmit light, or a polycarbonate (PC) series. It is manufactured in a flat type.

The light guide plate 200 has excellent transparency, weather resistance, and colorability to induce diffusion of light when light passes through it.

The light guide plate 200 connects the light incident surface 201a corresponding to the LED assembly 129, the light incident surface 201b on the opposite side thereof, and the light incident surface 201a and the incident light surface 201b, and connects the light incident surface 201b to the upper part from which light is emitted. It consists of a surface 201c, a lower surface 201d facing the reflecting plate 125, and both side surfaces 201e and 201f facing each other.

The light guide plate 200 includes a pattern 210 having a specific shape on its lower surface to supply a uniform surface light source. In particular, the pattern 210 included in the light guide plate 200 of the present invention is a curved liquid crystal display device. (100 in FIG. 2) is characterized in that it is formed to have a specific interval to realize the optimal effect. We will look at this in more detail later.

In addition, the optical sheet 121 is positioned on the upper surface 201c of the light guide plate 200 , and the optical sheet 121 includes a diffusion sheet and at least one light collecting sheet, and transmits the light passing through the light guide plate 200 . diffuse or condensed.

Accordingly, the light emitted from the plurality of LEDs 129a is incident into the light guide plate 200 through the light incident surface 201a of the light guide plate 200 , and the light incident into the light guide plate 200 is the lower surface of the light guide plate 200 . Through the pattern 210 provided in 201d, it travels inside the light guide plate 200 by total reflection several times and evenly spreads into the light guide plate 200, while some light passes through the lower surface 201d of the light guide plate 200. will be released

At this time, the light emitted to the lower portion of the light guide plate 200 is reflected by the reflective plate 125 positioned below the light guide plate 200 and is emitted back to the front of the light guide plate 200, thereby improving the luminance of the light.

The curved backlight unit 120 is provided to be concavely curved with respect to the front where the curved liquid crystal panel (110 in FIG. 2) is positioned, and is substantially perpendicular to one edge where the LED assembly 129 is positioned. curved in one direction.

That is, both side surfaces 201e and 201f of the light guide plate 200 perpendicular to the light incident surface 201a are curved to form a concavely curved state with respect to the front as a whole.

Here, in more detail with respect to the pattern 210 provided on the lower surface 201d of the light guide plate 200 according to the embodiment of the present invention, as shown in FIGS. 4 and 5 , the lower surface of the light guide plate 200 . At 201d, a plurality of pyramid patterns are distributed and spaced apart from each other by a predetermined interval, and the pyramid pattern 210 is formed in an intaglio form from the lower surface 201d of the light guide plate 200 .

Here, as shown in FIG. 5 , the pyramid pattern 210 includes a lower surface 211 formed in a square shape, and four side surfaces 213 extending from the edge of the lower surface 211 to form one corner.

The height (h) of the pyramid pattern 210 preferably corresponds to 1/2 of the width (w). That is, if the height of the pyramid pattern 210 is 15 μm, the width w of the pyramid pattern 210 corresponding to one length of the lower surface 211 is formed to have a width of 30 μm.

Accordingly, the pyramid pattern 210 allows a greater amount of light to be totally reflected to the entire area of the light guide plate 200 compared to the hemi-sphere pattern, so that in the curved liquid crystal display device (100 in FIG. 2 ), Compared to the dome pattern, the output efficiency is better.

Emission efficiency (%) Sample 1 81% Sample 2 85%

Prior to the description, Sample 1 is the emission efficiency measured by measuring the amount of light emitted from the light guide plate in a curved liquid crystal display having a dome pattern as the lower surface of the light guide plate, and Sample 2 is the lower surface of the light guide plate 200 ( 201d) shows the emission efficiency obtained by measuring the amount of light emitted from the light guide plate 200 in the curved liquid crystal display device (100 in FIG. 2 ) provided with the pyramid pattern 210 .

Looking at (Table 1) above, the emission efficiency of the curved liquid crystal display device (100 in FIG. 2) provided with the pyramid pattern 210 as the lower surface 201d of the light guide plate 200 is the dome pattern on the lower surface of the light guide plate. It can be seen that the emission efficiency is 4% higher than that of the provided curved liquid crystal display device.

This is to allow a greater amount of light to be totally reflected in the light guide plate 200 than the dome pattern in the pyramid pattern 210 in the curved liquid crystal display device (100 in FIG. 2 ), so that it is evenly spread in the light guide plate 200 because it can

The following (Table 2) shows the lower surface 201d of the light guide plate 200 in a flat liquid crystal display device and a curved liquid crystal display device (100 in FIG. 2) when a dome pattern and a pyramid pattern 210 are respectively provided. This is the experimental result of measuring the light concentration ratio (R _LED ) at the light incident part.

Change of light concentration ratio (R _LED ) dome pattern pyramid pattern Flat liquid crystal display (flat) 67% 70% Curved liquid crystal display (20R) 54% (-13%) 46% (-24%)

Prior to the description, R in 20R of the curved liquid crystal display device ( 100 in FIG. 2 ) denotes a curvature (R) and may be defined as a radius of curvature indicating the curvature of an arc of a circle having a radius R.

Here, 20R means an arc with a radius of 0.02 meters.

And, the light concentration ratio (R _LED ) can be defined through (Equation 1) below.

(Equation 1)

H denotes a longitudinal direction of the light guide plate 200 , and V denotes a longitudinal direction from the light incident surface 201a perpendicular to the longitudinal direction of the light guide plate 200 toward the incoming light surface 201b.

Hereinafter, for convenience of explanation, the longitudinal direction (H) of the light guide plate 200 is defined as the X-axis direction in the drawing, and the light-incoming surface ( The longitudinal direction V toward 201b) is defined as the Z-axis direction.

In addition, the light incident portion divides the lower surface 201d of the light guide plate 200 from the light incident surface 201a perpendicular to the longitudinal direction H of the light guide plate 200 to the incoming light surface 201b into three regions having the same width. Next, a region adjacent to the light incident surface 201a is defined as a light incident portion S1 , and an area adjacent to the incoming light surface 201b is defined as a light incoming portion S2 , and between the light incident portion S1 and the incoming light portion S2 . The area of is to be defined as the central part S3.

Referring to (Table 2) and FIGS. 6A to 6D above, when a dome pattern is provided on the lower surface of the light guide plate, in the curved liquid crystal display (100 in FIG. 2) compared to the flat liquid crystal display, in the light incident part S1 It can be seen that the light concentration ratio (R _LED ) of the LED is lowered by only 13%. When the pyramid pattern 210 is provided on the lower surface 201d of the light guide plate 200, compared to the flat panel liquid crystal display, it is a curved type. It can be seen that in the liquid crystal display device (100 in FIG. 2 ), the light concentration ratio (R _LED ) in the light incident part S1 is reduced by 24%.

Here, when the light concentration ratio R _LED in the light incident part S1 is lowered, more light emitted from the plurality of LEDs 129a and incident into the light guide plate 200 is directed toward the light guide plate 200 toward the light incident part S2. ) means total reflection within the

6A to 6B, in the process in which the light incident into the light guide plate through the light incident surface of the light guide plate is totally reflected by the dome pattern, the curved liquid crystal display exhibits some light compared to the flat liquid crystal display. It can be seen that the light, which is the opposite direction of , is totally reflected in the direction in which it was incident.

This is because the dome pattern changes the direction of total reflection of light according to the curved surface of the curved liquid crystal display.

On the other hand, referring to FIGS. 6C to 6D , when the pyramid pattern 210 is provided on the lower surface 201d of the light guide plate 200, both the flat liquid crystal display device and the curved liquid crystal display device 100 in FIG. It can be seen that the light incident into the light guide plate 200 is totally reflected toward the light-transmitting portion S2 in the direction in which the light travels without a significant difference.

In particular, comparing FIGS. 6B and 6D , when the pyramid pattern 210 is provided on the lower surface 201d of the light guide plate 200 , the curved liquid crystal display device ( 100 in FIG. 2 ) emits more light. It can be seen that the light is totally reflected toward the anti-light portion S2, which is the direction in which the light travels, and through this, it can be seen that the light is more uniformly spread over the entire area of the light guide plate 200 .

Therefore, in the curved liquid crystal display device ( 100 in FIG. 2 ), it can be seen that having the pyramid pattern 210 as the lower surface 201d of the light guide plate 200 has better emitting efficiency than having the dome pattern. .

On the other hand, as can be seen from (Table 1) above, the curved liquid crystal display device (100 in FIG. 2) has the light incident part S1 even though the pyramid pattern 210 is provided on the lower surface 201d of the light guide plate 200. The light concentration ratio (R _LED ) is high at 46%, and referring to the illuminance profile of FIG. 7A , it can be seen that the uniformity of the light emitted from the light guide plate 200 is very low at 18.5.

Accordingly, it is preferable to form the pyramid pattern 210 provided on the lower surface 201d of the light guide plate 200 at a lower density per unit area as it approaches the LED assembly 129 and at a higher density as it moves away from the LED assembly 129 .

That is, the pyramid pattern 210 in the light incident part S1 is formed at a low density per unit area, and the pyramid pattern 210 in the light incident part S2 is formed at a higher density per unit area compared to the light incident part S1. The pyramid pattern 210 in the light portion S1 is formed so that the spacing between the patterns is wider than the spacing between the pyramid patterns 210 of the anti-light portion S2 .

At this time, the pyramid pattern 210 is disposed to have the same spacing in each region S1 , S2 , and S3 . In the light incident portion S1 adjacent to the LED assembly 129 , the pyramid pattern 210 is all first When arranged to have an interval a', the pyramid patterns 210 located in the central portion S3 located between the light incident portion S1 and the light incoming portion S2 are all second smaller than the first interval a′. The pyramid patterns 210 are arranged to have an interval b', and are arranged to have a third interval a' smaller than the second interval b′.

Accordingly, as shown in FIG. 7B , it can be seen that the uniformity of light emitted from the light guide plate 200 is improved to 1.24.

Through this, light can be more uniformly emitted from the light guide plate 200 .

At this time, the distances (a', b', c') between the pyramid patterns 210 adjacent to each other in the X-axis direction defined in the drawing, which is the longitudinal direction H of the light guide plate 200 , are determined by the bending of the light guide plate 200 . Although it does not significantly affect the uniformity of light emitted from 200 , the incoming light surface 201b from the light incident surface 201a perpendicular to the longitudinal direction H of the light guide plate 200 corresponds to the curved direction of the light guide plate 200 . ), the distances (a, b) between the pyramid patterns 210 positioned adjacent to each other in the Z-axis direction defined in the drawing, which is the longitudinal direction (V) toward the It affects the light uniformity.

In particular, light emitted from the LED assembly 129 in the Z-axis direction defined in the drawing of the light guide plate 200 is incident inside through the light incident surface 201a of the light guide plate 200 and proceeds toward the incoming light surface 201b. Since it is the same as the propagation direction of light, the intervals (a, b) between the pyramid patterns 210 adjacent to each other in the Z-axis direction defined in the drawing perpendicular to the longitudinal direction (H) of the light guide plate 200 are equal to the light guide plate ( The bending of the light guide plate 200 affects the uniformity of light emitted from the light guide plate 200 .

Accordingly, the pyramid patterns 210 adjacent in the Z-axis direction, which affect the uniformity of light according to the bending of the light guide plate 200, are defined through (Equation 2) below, and are spaced at regular intervals for each region S1, S2, and S3. It is preferable to arrange so as to have (a, b).

(Equation 2)

(

)

)

In (Equation 2),

= 도광판(200) 곡면(휨) 각도, v = 입광부(S1) 기준 하부면(201d)에 위치하는 피라미드 패턴(210)이 있는 도광판(200)의 위치, L = 도광판(200)의 입광면(201a)에서 반입광면(201b)까지의 길이,

= (L'/L)(L': 적용된 도광판(200)의 입광면(201a)에서 반입광면(201b)까지의 길이, L = 표준 도광판(200)의 입광면(201a)에서 반입광면(201b)까지의 길이),

= 도광판(200)의 길이방향(H)에서의 등간격 패턴 간격,

= 도광판(200)의 입광면(201a)에서 반입광면(201b)까지의 길이방향(V)에서 등간격 패턴 간격,

= 도광판(200)의 굴절율에 따른 패턴 간격 변화율 상수,

= 도광판(200)의 굴절율에 따른 패턴 변화율 상수를 의미한다.

= the angle of the curved surface (bending) of the light guide plate 200, v = the position of the light guide plate 200 having the pyramid pattern 210 positioned on the reference lower surface 201d of the light incident part S1, L = the light incident surface of the light guide plate 200 The length from (201a) to the incoming light surface (201b),

= (L'/L)(L': the length from the light incident surface 201a to the incoming light surface 201b of the applied light guide plate 200 , L = the light incident surface 201a to the incoming light surface 201b of the standard light guide plate 200 ) ) to length),

= equally spaced pattern spacing in the longitudinal direction (H) of the light guide plate 200,

= equally spaced pattern intervals in the longitudinal direction (V) from the light incident surface 201a of the light guide plate 200 to the incoming light surface 201b;

= constant rate of change of pattern spacing according to the refractive index of the light guide plate 200;

= means a pattern change rate constant according to the refractive index of the light guide plate 200 .

≤ π(rad) 범위 내에 위치하는 것이 바람직하며, 도광판(200)의 길이방향(H)에서의 등간격 패턴 간격과, 도광판(200)의 입광면(201a)에서 반입광면(201b)까지의 길이방향(V)에서의 등간격 패턴 간격은 1.5(w)에 비해 큰 것이 바람직하다. Here, the curved surface (bending) angle of the light guide plate 200 is 0 ≤

It is preferable to be located within the range of ≤ π (rad), and the equally spaced pattern interval in the longitudinal direction H of the light guide plate 200 and the length from the light incident surface 201a to the incoming light surface 201b of the light guide plate 200 . It is preferable that the equally spaced pattern spacing in the direction (V) be larger than 1.5 (w).

For example, when the width of the pyramid pattern 210 is 0.03 mm, Iv and Ih have values greater than 0.045.

Here, for convenience of explanation, a predetermined condition is substituted for the above (Equation 2), and as an embodiment, the intervals (a, b) between the pyramid patterns 210 provided on the lower surface 201d of the light guide plate 200 . Let's try to define

Through the above (Equation 2), the pyramid pattern 210 provided in the light incident portion S1 of the lower surface 220d of the light guide plate 220 has a spacing (a) of 0.32 to 0.37 mm in the Z-axis direction defined in the drawing. ), and the pyramid pattern 210 provided in the carry-in light unit S2 is spaced apart with an interval b of 0.063 to 0.8 mm in the z-axis direction defined on the drawing by Equation 2 above. to be placed and placed.

= 0도, 20도, 60도, 120도로 대입하였으며, L은 64.4mm를, H는 202mm를, Iv와 Ih는 0.06mm, α는 9.566, γ는 2.810으로 대입하였다. here,

= 0 degrees, 20 degrees, 60 degrees, and 120 degrees, L was substituted with 64.4 mm, H with 202 mm, Iv and Ih with 0.06 mm, α with 9.566, and γ with 2.810.

은 굴절율 상수인 n=1.494(550nm)를 대입하여, 0.079가 대입되었으며,

은 0.188을 대입하여 계산된 결과이다. and,

By substituting n = 1.494 (550 nm), the refractive index constant of silver, 0.079 was substituted,

is the calculated result by substituting 0.188.

The results calculated according to the radius of curvature in the above (Equation 2) are summarized in the following (Table 3).

radius of curvature Flat 120R 60R 20R

)Light guide plate curved surface (bending) angle (

) 0° 30° 60° 180° I _{near LED} (light incident part: S1) 0.37mm 0.36mm 0.35mm 0.32mm I _{far from LED} (Incoming light: S2) 0.063mm 0.064mm 0.07mm 0.08mm Aspect Ratio (AI)
(aspect ratio of pattern interval) 5.86 5.65 5.1 3.82

Before the explanation, the aspect ratio (AI) is defined as I _{near LED} / I _{far from LED} .

Looking at the above (Equation 2) and (Table 3), in the case of a flat panel liquid crystal display, the pyramid pattern located in the light incident part is arranged to have an interval of 0.37 mm in the Z-axis direction defined in the drawing, and the It is preferable to arrange the pyramid pattern positioned to have an interval of 0.063 mm in the Z-axis direction defined in the drawing. In the case of a 20R curved liquid crystal display device, the pyramid pattern 210 positioned in the light incident part S1 is shown in the drawing. The pyramid pattern 210 positioned in the light-in part S2 is arranged to have an interval (a) of 0.32 mm in the Z-axis direction defined as above, and a spacing (b) of 0.008 mm in the Z-axis direction defined in the drawing. to have an optimal condition to improve the uniformity of light.

Here, referring to (Table 3) above, as the radius of curvature of the light guide plate 200 decreases, the interval a between the pyramid patterns 210 positioned at the light incident part S1 is the pyramid of the flat panel liquid crystal display device. It can be seen that the interval between the patterns is decreased compared to the interval between the patterns, and the interval b between the pyramid patterns 210 positioned in the light-receiving portion S2 is increased.

Through this, in the curved liquid crystal display device (100 in FIG. 2 ) according to the embodiment of the present invention, as the radius of curvature of the light guide plate 200 increases, the light incident part S1 and the light-incoming part ( It can be defined that it is preferable to arrange the arrangement so that the change in the aspect ratio (a/b) according to the spacing (a, b) between the neighboring pyramid patterns 210 positioned at S2) is reduced.

That is, in the curved liquid crystal display device 100 in FIG. 2 according to the embodiment of the present invention, the lower surface 201d of the light guide plate 200 of the curved backlight unit 120 in FIG. 3 has an X-axis direction defined in the drawing. A pyramid pattern 210 having the same spacing (a', b', c') is provided as the , and variable spacing (a, b) for each region S1 and S2 in the Z-axis direction defined in the drawing. ) to have a pyramidal pattern with

At this time, the pyramid pattern 210 having variable intervals a and b is provided at a low density to a high density per unit area as it goes from the light incident part S1 to the light incoming part S2. As the radius of curvature of 100) of 2 increases, the adjacent interval a in the Z-axis direction defined in the drawing of the pyramid pattern 210 positioned at the light incident part S1 and the pyramid pattern positioned at the light-incoming part S2 (210) is designed to increase the aspect ratio (a/b) of the interval (b) between adjacent in the Z-axis direction defined in the drawing.

That is, the flat-panel liquid crystal display device has an infinite radius of curvature, and the aspect ratio of the interval between the light incident portion and the incoming light portion of the pyramid pattern adjacent in the Z-axis direction defined in the drawing is 5.86, In the curved liquid crystal display device having 20R (100 in FIG. 2 ), as the radius of curvature decreases, the interval (a) between the light incident part (S1) of the pyramid pattern 210 adjacent in the Z-axis direction as defined in the drawing and It is designed so that the aspect ratio (a/b) of the gap (b) in the light-in part S2 is reduced to 3.82.

Through this, the curved liquid crystal display device ( 100 in FIG. 2 ) according to the embodiment of the present invention can emit more uniform light.

The following (Table 4) shows when the pyramid patterns on the lower surface of the light guide plate in the curved liquid crystal display device (100 in FIG. 2 ) are formed to have the same spacing, and the lower surface of the light guide plate 200 as in the embodiment of the present invention. (201d) is an experimental result of comparing and measuring the illuminance profile when the pyramid pattern 210 is formed to have variable intervals (a, b) in the Z-axis direction defined in the drawing.

radius of curvature Sample 3 Sample 4 120R

uniformity 6% 80% 60R

uniformity 6% 80% 20R

uniformity 5.6% 80%

Prior to the description, Sample 3 shows a curved liquid crystal display device having a pyramid pattern having the same spacing in both the X-axis direction and the Z-axis direction defined in the drawing on the lower surface of the light guide plate, and Sample 4 shows the implementation of the present invention. The lower surface 201d of the light guide plate 200 according to the example has the same distances a', b', c' in the X-axis direction defined in the drawing, and variable intervals in the Z-axis direction defined in the drawing. A curved liquid crystal display device ( 100 in FIG. 2 ) provided with a pyramid pattern 210 having (a, b) is shown.

In particular, Sample 4 shows the aspect ratio (a) of the interval (a) between the light incident portion (S1) and the interval (b) at the incoming light portion (S2) of the pyramid pattern 210 adjacent in the Z-axis direction defined in the drawing. /b) is designed to be reduced compared to the flat-panel liquid crystal display.

Looking at the above (Table 4), it can be seen that the roughness profile of all Sample 3 is not uniform, and in particular, it can be confirmed that the roughness profile is more non-uniform as the radius of curvature increases.

In addition, it can be seen that the uniformity is also very low at 5.6 to 6%.

On the other hand, it can be seen that all of Sample 4 has a uniform illuminance profile, and it can be seen that the uniformity is also very high at 80%. so that the aspect ratio (a/b) of the interval (a) between the light incident portion (S1) of the adjacent pyramid pattern 210 and the interval (b) at the incoming light portion (S2) of the adjacent pyramid pattern 210 is reduced compared to that of the flat panel type liquid crystal display device. It can be confirmed that the curved liquid crystal display device ( 100 in FIG. 2 ) according to the embodiment of the present invention to be designed can emit more uniform light.

As described above, the curved liquid crystal display device 100 in FIG. 2 according to the embodiment of the present invention has a pyramid pattern provided on the lower surface 201d of the light guide plate 200 of the curved backlight unit 120 in FIG. 3 . The curved liquid crystal display device (FIG. In 100) of 2, the emission efficiency can be further improved, and more uniform light can be emitted.

Accordingly, according to the present invention, it is possible to prevent the screen quality from being deteriorated due to non-uniform luminance of the curved liquid crystal display device ( 100 in FIG. 2 ).

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: light guide plate
201a: light incident surface, 201b: incoming light surface, 201c: upper surface, 201d: lower surface, 201e, 201f: side
210: pyramid pattern

Claims (9)

a reflector;
a light guide plate that is seated on the reflecting plate and has a pyramid pattern disposed thereon so as to have a variable interval in the longitudinal direction from the light incident surface to the incoming light surface;
an LED assembly arranged along the light incident surface of the light guide plate;
an optical sheet mounted on the light guide plate;
A curved liquid crystal panel seated on the optical sheet
includes,
The pyramid patterns are arranged adjacent to each other so as to have a first interval at the light-incoming portion adjacent to the light-incoming surface in the longitudinal direction from the light-incoming surface toward the incoming light-incoming surface, and in the incoming light-injecting portion adjacent to the incoming light-incoming surface, the first interval is narrower than the first interval. 2 They are arranged adjacent to each other so that there is a gap between them,
As the radius of curvature of the light guide plate increases, the aspect ratio of the first interval and the second interval (= the first interval/the second interval) increases.
The method of claim 1,
The interval between the first and the second interval is

(

)
is defined through

= the angle of the curved surface (bending) of the light guide plate, v = the position of the light guide plate with the pyramid pattern located on the lower surface of the light incident part reference, L = the length from the light incident surface to the incoming light surface of the light guide plate,

= (L'/L)(L': the length from the light incident surface to the incoming light surface of the applied light guide plate, L = the length from the light incident surface to the incoming light surface of the standard light guide plate),

= equally spaced pattern spacing in the longitudinal direction (H) of the light guide plate,

= equally spaced pattern spacing in the longitudinal direction (V) from the light incident face to the incoming light face of the light guide plate,

= constant rate of change of pattern spacing according to the refractive index of the light guide plate,

= means the pattern change rate constant according to the refractive index of the light guide plate,
The angle of the curved surface (bending) of the light guide plate is 0 ≤

It is located within the range of ≤ π (rad),
remind

and above

A curved liquid crystal display that is larger than 1.5(w) (w = the width of the lower surface of the pyramid pattern).
The method of claim 1,
The pyramid pattern is disposed adjacent to each other so as to have equal intervals in the longitudinal direction of the light guide plate.
The method of claim 1,
The pyramid pattern is made in the form of an intaglio from the lower surface,
It includes a lower surface made of a square, and four side surfaces each extending from the edge of the lower surface to form one corner,
A height of the pyramid pattern is 1/2 of a width corresponding to one length of the lower surface of the curved liquid crystal display.
3. The method of claim 2,
The light guide plate curved surface (bending) angle (

) is 0 degrees, the first interval is 0.37mm, the second interval is 0.063mm,
The light guide plate curved surface (bending) angle (

) is 20 degrees, the first interval is 0.32mm, the second interval is 0.08mm,
The light guide plate curved surface (bending) angle (

) increases, the first interval decreases, and the second interval increases.

The method of claim 1,
The curved liquid crystal panel is curved concavely toward the front in which the image is realized,
The light guide plate, the reflection plate, and the optical sheet are curved concavely toward the front in which the curved liquid crystal panel is positioned.
7. The method of claim 6,
A curved guide panel surrounding the edge of the curved liquid crystal panel,
A curved cover bottom configured in close contact with the curved guide panel,
and a curved top cover that borders the edge of the curved liquid crystal panel and is assembled and coupled to the curved guide panel and the curved cover bottom,
The curved guide panel, the cover bottom, and the curved top cover are curved to have a curvature corresponding to the curvature of the curved liquid crystal panel. The method of claim 1,
The light guide plate is configured to be bent along a longitudinal direction from the light incident surface to the incoming light surface.
Curved liquid crystal display.
9. The method of claim 8,
The light incident surface has a flat shape that is not curved.
Curved liquid crystal display.

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