KR101815553B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display, and more particularly to a liquid crystal display capable of minimizing light loss.
A feature of the present invention resides in that in an direct light type liquid crystal display device, an IMM tape (index matching material tape) is interposed between an LED and a diffusion plate to provide a color mixing space for light emitted from the LED, While minimizing optical loss by removing optical gaps or air gaps through the IMM tape.
As a result, the light efficiency of the liquid crystal display device is improved, and the problem of improving the power consumption of the liquid crystal display device can be prevented.
Further, when the LEDs are intended to have the same luminance, the number of LEDs can be reduced, thereby eliminating the problem of cost increase and heat dissipation, and the increase in power consumption can be solved , And LED mura phenomenon can be prevented.

Description

[0001] Liquid crystal display device [0002]

The present invention relates to a liquid crystal display, and more particularly to a liquid crystal display capable of minimizing light loss.

2. Description of the Related Art Recently, display devices capable of visually displaying information together with development of information technology and mobile communication technology have been developed, and display devices are classified into a self-luminous display having a luminescent characteristic and an image Emitting display that can be used as a display device.

As a non-light emitting type display, a liquid crystal display (hereinafter referred to as LCD) is exemplified.

Here, the LCD requires an additional light source since it is an element that does not have its own light emitting element. Accordingly, a backlight unit having a light source on the back surface is provided, and light is irradiated toward the front surface of the LCD, thereby realizing an image which can be identified only through the backlight unit.

The backlight unit uses a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp, and a light emitting diode (LED) as a light source.

In particular, LEDs are widely used as light sources for displays, having characteristics such as small size, low power consumption, and high reliability.

Meanwhile, a general backlight unit is divided into a side light type and a direct light type according to the arrangement structure of the lamp. In the sidelight type, one or a pair of lamps are disposed on one side of the light guide plate Or two or two pairs of lamps are disposed on both side portions of the light guide plate, and the direct light type lamp has a structure in which several lamps are disposed under the optical sheet.

In recent years, research on liquid crystal display devices that are large-sized according to the demand of consumers has been actively conducted, and the direct light type is more suitable for a large-screen liquid crystal display device than the sidelight type.

1 is a cross-sectional view of a direct light type liquid crystal display device using a general LED as a light source.

As shown in the figure, a typical liquid crystal display device is provided with a liquid crystal panel 10 composed of first and second substrates 12 and 14 and a backlight unit 20 behind the liquid crystal panel 10.

Here, the backlight unit 20 includes a reflection plate 22, and a plurality of LEDs 28 are arranged in parallel on the upper surface of the backlight unit 20. A diffusion plate 26 and a plurality of optical sheets 27 are located.

At this time, the lights emitted from two or three neighboring LEDs 28 are superimposed and mixed with each other, and then incident on the liquid crystal panel 10 to provide a surface light source.

The backlight unit 20 including the LED 28 and the liquid crystal panel 10 are modularized through the top cover 40, the support main 30 and the cover bottom 50, that is, the liquid crystal panel 10 and the backlight A top cover 40 for covering the front edge of the liquid crystal panel 10 and a cover bottom 50 for covering the back surface of the backlight unit 20 in a state where the edge of the unit 20 is covered with the square main support base 30 And are integrated through the support main body 30.

The direct-ride-type backlight unit 20 using the LED 28 as a light source has an optical gap or an air gap between the reflection plate 22 and the diffusion plate 26, .

The optical gap or air gap (hereinafter referred to as an air gap A) is a color mixing space of light emitted from the LED 28. The light emitted from the LED 28 is uniformly color- Or to prevent thermal expansion of the diffusion plate 26 due to the heat of high temperature generated from the LED 28.

However, this air gap A has a large optical refraction index deviation between the LED 28 and the diffuser plate 26, so that in the course of the light emitted from the LED 28 being incident on the diffuser plate 26, The light emitted from the LED chip (not shown) of the LED 28 at the boundary between the respective media, that is, the LED 28 and the air gap A, Some light totally reflected at the boundary is not output to the outside of the LED 28 or is scattered and causes a problem of scattering also at the boundary of the air gap A and the diffuser plate 26. [

Therefore, light loss is caused, which causes a problem of improving power consumption.

SUMMARY OF THE INVENTION It is a first object of the present invention to improve optical efficiency of a liquid crystal display by minimizing optical loss.

Accordingly, a second object of the present invention is to provide a liquid crystal display device of high luminance.

In order to achieve the above-mentioned object, the present invention provides a liquid crystal display comprising: a reflection plate; An LED assembly including a plurality of LEDs positioned on the reflection plate and a PCB on which a plurality of LEDs are mounted; A diffusion plate disposed on the LED assembly; An IMM tape interposed between the LED and the diffuser plate; An optical sheet positioned above the diffusion plate; And a liquid crystal panel disposed on the plurality of optical sheets. The IMM tape provides a liquid crystal display having a light refractive index of 1.4 to 1.53.

At this time, the IMM tape has a thickness of 50 to 70 lb./ft. ³ , and the IMM tape has a thickness of 0.5 to 2.5 mm.

One side of the IMM tape is in contact with the LED, the other side of the IMM tape is in contact with the diffusion plate, and the IMM tape is overlapped with the LED to cover the side of the LED.

Also, a diffusion plate support for preventing deflection of the diffusion plate is provided, and the portion where the diffusion plate support is formed is separated from the IMM tape into a plurality of parts.

As described above, in the direct light type liquid crystal display device according to the present invention, the IMM tape is interposed between the LED and the diffusing plate to provide a color mixing space for the light emitted from the LED, and thermal expansion of the diffusing plate occurs And the optical gap or the air gap is removed through the IMM tape, thereby minimizing optical loss.

Accordingly, the light efficiency of the liquid crystal display device is improved, and the problem of improving the power consumption of the liquid crystal display device can be prevented.

In addition, the LED can be widened in the directional angle, and when it is desired to realize the same luminance, the number of LEDs can be reduced, and cost increase and heat dissipation problem can be solved. There is an effect that the LED mura phenomenon can be prevented.

1 is a sectional view of a direct light type liquid crystal display device using a general LED as a light source.
2 is an exploded perspective view illustrating a liquid crystal display device according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view schematically showing a part of a modularized view of the liquid crystal display device according to the embodiment of the present invention shown in FIG. 2; FIG.
4 is a simulation result in which the amount of light emitted from the LED is calculated according to the light refractive index of the IMM tape.
5A to 5B are simulation results of calculating the amount of light loss of a conventional liquid crystal display device.
6A to 6B are simulation results of calculating the amount of light loss of the liquid crystal display device according to the embodiment of the present invention.
7A to 7B are cross-sectional views illustrating the progress of light emitted from an LED of a liquid crystal display according to an exemplary embodiment of the present invention.
8A to 8B are cross-sectional views schematically showing a part of a modular view of a liquid crystal display device according to a second embodiment of the present invention.

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

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

As shown, the liquid crystal display comprises a liquid crystal panel 110, a backlight unit 120, a support main 130, a cover bottom 150, and a top cover 140.

First, the liquid crystal panel 110 plays a key role in image display and includes first and second substrates 112 and 114 which are bonded to each other with a liquid crystal layer interposed therebetween.

At this time, a plurality of gate lines and data lines intersect with each other on the inner surface of the first substrate 112, which is usually referred to as a lower substrate or an array substrate, although not clearly shown in the figure, And a thin film transistor (TFT) is provided at each intersection point and is connected in a one-to-one correspondence with the transparent pixel electrode formed in each pixel.

On the inner surface of the second substrate 114 called an upper substrate or a color filter substrate, color filters of red (R), green (G), and blue (B) And a black matrix for covering non-display elements such as a gate line, a data line, and a thin film transistor. In addition, a transparent common electrode covering these elements is provided.

The printed circuit boards 118a and 118b are connected to each other along at least one edge of the liquid crystal panel 110 via a connecting member 116 such as a flexible circuit board so that the side surfaces or the cover bottoms (150).

Although not clearly shown in the figure, an upper and a lower alignment film (not shown) for determining the initial alignment direction of the liquid crystal are interposed at the boundary between the two substrates 112 and 114 of the liquid crystal panel 110 and the liquid crystal layer A seal pattern is formed along the edges of both substrates 112 and 114 to prevent leakage of the liquid crystal layer filled therebetween.

Upper and lower polarizers (not shown) are attached to the outer surfaces of the first and second substrates 112 and 114, respectively.

A backlight unit 120 for supplying light to the back surface of the liquid crystal panel 110 is provided so that a difference in transmittance represented by the liquid crystal panel 110 is externally manifested.

The backlight unit 120 includes an LED assembly 128, an index matching material tape 200 positioned on the LED assembly 128, a diffuser plate 126 located on the IMM tape 200, And an optical sheet 127 positioned on the upper side.

The LED assembly 128 described above includes a PCB 128b arranged to have a constant spacing along the longitudinal inner surface of the cover bottom 150 and a plurality of LEDs 128a mounted on each of them.

Here, the plurality of LEDs 128a emit light having colors of red (R), green (G) and blue (B), respectively, and by turning on the plurality of RGB LEDs 128a at once, Can be implemented.

On the other hand, the LED 128a that implements white light may be composed of a blue LED chip (not shown) and a yellow phosphor, and the yellow phosphor may include cerium (Ce) -doped yttrium aluminum (Al) garnet YAG: Ce (T3Al5O12: Ce) based phosphor is preferably used.

When a UVLED chip is used, the phosphor (not shown) is composed of three phosphors of red (R), green (G), and blue (B) The luminescent color can be selected by controlling the compounding ratio of the red (R), green (G), and blue (B) phosphors (not shown).

Here, the red (R) phosphor is a YOX (Y2O3: EU) based phosphor composed of a compound of yttrium oxide (Y2O3) and europium (EU) having a main wavelength of 611 nm and the green (G) (LaPo4: Ce, Tb) phosphor, which is a compound of phosphorus (Po4) and lanthanum (La) and terbium (Tb) having a dominant wavelength as a main wavelength, and a blue phosphor (B) BAM blue (BaMgAl 10 O 17: EU) based phosphor which is a compound of Eu and Eu and a substance of magnesium oxide and aluminum oxide are preferably used.

Here, the dominant wavelength is the wavelength at which the highest luminance is generated in red (R), green (G), and blue (B), respectively, as the dominant wavelength of the phosphor.

On the other hand, by using the LED 128a constituted by an LED chip (not shown) that emits all the colors of RGB, it is possible to realize white light in each LED 128a, or to realize a white color including a white- The emitting LED 128a may also be used.

The PCB 128b on which the plurality of LEDs 128a are mounted is a metal core printed circuit board having a heat dissipating function and a heat sink (not shown) is provided on the back surface of the MCPCB 128b It is possible to transfer heat from the LED 128a of the light emitting diode 128a to the outside.

The backlight unit 120 includes a plurality of through holes 123 through which a plurality of LEDs 128a can pass so that the PCB 128b except for the plurality of LEDs 128a and the entire inner surface of the cover bottom 150 And includes a reflective white or silver reflector 122.

A diffuser plate 126 and an optical sheet 127 for uniformity of brightness are positioned above the LEDs 128a exposed through the through holes 123 of the reflector 122.

At this time, the diffusion plate 126 of the present invention disperses and diffuses the light emitted from the plurality of LEDs 128a, thereby realizing a more uniform surface light source and increasing color mixing.

The optical sheet 127 positioned on the diffusion plate 126 is made of a diffusion sheet and at least one light condensing sheet and includes various functional sheets such as a reflection type polarizing film called DBEF (dual brightness enhancement film) .

Accordingly, the light emitted from the plurality of LEDs 128a passes through the diffusion plate 126 and the optical sheet 127 in order, and then enters the liquid crystal panel 110. By using the light, the liquid crystal panel 110 can emit a high- As shown in FIG.

The backlight unit 120 of the present invention is characterized in that the IMM tape 200 is interposed between the plurality of LEDs 128a and the diffusion plate 126. [

The IMM tape 200 serves to provide a color mixing space for the light emitted from the plurality of LEDs 128a while preventing thermal expansion of the diffusion plate 126 due to the heat generated from the LEDs 128a.

In particular, the air gap (A in FIG. 1) between the plurality of LEDs 128a and the diffusion plate 126 is removed to minimize the light loss. Let me take a closer look at this later.

The liquid crystal panel 110 and the backlight unit 120 are modularized through a top cover 140, a support main 130 and a cover bottom 150. The top cover 140 is disposed on the upper surface and the side surface of the liquid crystal panel 110, And the front cover 150 is opened to display an image to be displayed on the liquid crystal panel 110. The liquid crystal panel 110 may be a liquid crystal panel.

The cover bottom 150 which is based on the assembly of the entire liquid crystal display device with the liquid crystal panel 110 and the backlight unit 120 mounted thereon is formed into a square plate shape, And a pair of side supports 129 in the form of a pair of bars joined to the edges of the cover bottom 150. The remaining two edges of the cover bottom 150 are bent at an oblique angle so as to have a height equal to the height, Thereby forming a predetermined space in which the base 120 can be seated.

The support main body 130 which is mounted on the cover bottom 150 and has a rectangular frame shape covering the edges of the liquid crystal panel 110 and the backlight unit 120 is combined with the top cover 140 and the cover bottom 150.

The top cover 150 may be referred to as a case top or a top case. The support main 130 may be referred to as a guide panel or a main support or a mold frame. The cover bottom 150 may be referred to as a bottom cover.

As described above, in the liquid crystal display of the present invention, the IMM tape 200 is sandwiched between the plurality of LEDs 128a and the diffusion plate 126, so that the color mixing space of the light emitted from the plurality of LEDs 128a So that thermal expansion of the diffusion plate 126 is prevented from occurring and the air gap (A in FIG. 1) is removed through the IMM tape 200, thereby minimizing optical loss.

This will be described in more detail with reference to FIG. 3 below.

FIG. 3 is a cross-sectional view schematically showing a part of a modularized view of the liquid crystal display device according to the embodiment of the present invention shown in FIG. 2, FIG. 4 is a graph showing the relationship between the light- Simulation results.

As shown in the figure, the IMM tape 200 is positioned above the LED assemblies 128 and the diffusion plate 126 is disposed on the IMM tape 200 .

The optical sheet 127 and the liquid crystal panel 110 are sequentially stacked on the diffusion plate 126.

One side of the IMM tape 200 is in contact with a plurality of LEDs 128a mounted on the PCB 128b of the LED assembly 128 and the other side of the IMM tape 200 is in contact with the diffusion plate 126 .

The IMM tape 200 serves to provide a color mixing space for the light emitted from the plurality of LEDs 128a while preventing thermal expansion of the diffusion plate 126 due to the heat generated from the LEDs 128a.

Particularly, the air gap (A in FIG. 1) between the plurality of LEDs 128a and the diffusion plate 126 is removed to minimize light loss.

In other words, the plurality of LEDs 128a are mixed with a transparent resin made of epoxy resin or silicon and positioned on the LED chip (not shown), and the transparent resin has a light refractive index of 1.53.

The diffuser plate 126 is made of acryl-based resin, polystryrene, heat resistant PS, polymethylmethacrylate (PMMA), polyethylene terephthalate (PET) or the like, and has a refractive index of 1.49.

When the air gap (A in FIG. 1) exists between the plurality of LEDs 128a and the diffusion plate 126, the air gap (A in FIG. 1) The difference in light refractive index between the resin and the diffusing plate 126 is large, so that light to be transmitted at the interface between each medium is totally scattered and scattered.

That is, at the boundary between the LED 128 and the air gap (FIG. 1A), light emitted from the LED chip (not shown) of the LED 128 is reflected by the air gap Some of the light is not emitted to the outside of the LED 128 or scattered. This results in optical loss.

The IMM tape 200 having a refractive index of 1.4 to 1.53 is placed between the plurality of LEDs 128a and the diffusion plate 126 so that the transparent resin of the LED 128a and the IMM tape 200, The difference in the refractive index between the diffusing plates 126 is reduced, so that light is reflected and scattered at the interface between the mediums is minimized.

Therefore, the optical loss can be reduced.

As a result, the light efficiency of the liquid crystal display device is improved, and the problem of improving the power consumption of the liquid crystal display device can be prevented.

4 is a simulation result in which the amount of light emitted from the LED 128a is calculated in accordance with the light refractive index of the IMM tape 200. FIG.

Referring to FIG. 4, as the LED 128a has a refractive index of 1.53, the closer the refractive index of the IMM tape 200 in contact with the LED 128a is to 1.53, the more light is emitted from the LED 128a It can be confirmed that the light amount increases.

Thus, it can be seen that when the light emitted from the LED 128a is incident into the medium having a similar optical refractive index, the loss of light is minimized.

FIGS. 5A to 5B are simulation results for calculating the amount of light loss of a conventional liquid crystal display device, and FIGS. 6A to 6B are simulation results for calculating a light loss amount of the liquid crystal display device according to an embodiment of the present invention.

5A is a graph showing the relationship between the amount of light transmitted and the amount of reflection at the boundary between the LED (128a in FIG. 3) and the air gap (FIG. 1A) by theoretically calculating Snell's law and Fresnel equations. And FIG. 5B is a graph for calculating the amount of light transmission and reflection at the boundary between the air gap (A in FIG. 1) and the diffuser plate (126 in FIG. 3).

6A is a graph illustrating a relationship between a light transmission amount and a reflection amount at a boundary between an LED (128a in FIG. 3) and an IMM tape (200 in FIG. 3) of a liquid crystal display according to an embodiment of the present invention, 6B is a graph for calculating the amount of light transmission and reflection at the boundary between the IMM tape (200 in FIG. 3) and the diffuser plate (126 in FIG. 3) .

5A and 5B and FIGS. 6A and 6B, the normalized intensity of light emitted from the LED (128a in FIG. 3) is output from the LED (128a in FIG. 3) to the incident angle and incident angle.

At this time, the light refractive index of the LED (128a in FIG. 3) is 1.53, the refractive index of the diffuser plate (126 in FIG. 3) is 1.49, and the IMM tape (200 in FIG. 3) has a light refractive index of 1.42.

Here, since the incident angle after the incident angle is equal to that of the incident light with respect to the incident angle, it means that all the incident angles are reflected. Therefore, the amount of reflected and lost light in FIG. 5A is about 60/52, and the amount of reflected and lost light in FIG. 20%. ≪ / RTI >

3). When an air gap (A in Fig. 1) exists between the LED (128a in Fig. 3) and the diffuser plate (126 in Fig. 3) ), The light to be transmitted at the interface between each medium is reflected and scattered, so that about 60% of light is reflected at the boundary between the LED (128a in FIG. 3) and the air gap Meaning that about 20% of the light is reflected and lost at the boundary between the air gap (A in FIG. 1) and the diffuser plate (126 in FIG. 3).

On the other hand, by locating the IMM tape (200 in FIG. 3) having a refractive index of 1.4 to 1.53 between the LED (128a in FIG. 3) and the diffuser plate (126 in FIG. 3) The amount of light reflected and lost in FIG. 6B is 5/90 to 5%. In the boundary between the LED (128a in FIG. 3) and the IMM tape (200 in FIG. 3), about 20% Meaning that only about 5% of the light is lost at the boundary between the IMM tape (200 in FIG. 3) and the diffuser plate (126 in FIG. 3).

In summary,

Optical loss (%) Difference The amount of light loss at the boundary between the LED and the optical gap or air gap 60% - Loss of light at the boundary between LED and IMM tape 20% -40% Optical loss or optical loss at the boundary between the optical gap or air gap and the diffuser plate 20% - The amount of light loss at the boundary between the IMM tape and the diffuser plate 5% -15%

3) and the diffuser plate (128a in FIG. 3) between the LED (128a in FIG. 3) and the diffuser plate (126 in FIG. 3), as in the embodiment of the present invention, An air gap (A in FIG. 1) is formed between the LED (128a in FIG. 3) and the diffuser plate (126 in FIG. 3) by locating the IMM tape (200 in FIG. 3) It can be seen that the optical loss can be reduced as compared with the case where it exists.

As a result, the light efficiency of the liquid crystal display device is improved, and the problem of improving the power consumption of the liquid crystal display device can be prevented.

The liquid crystal display according to the embodiment of the present invention further includes an IMM tape (200 in FIG. 3) having a light refractive index similar to the light refractive index of the transparent resin of the LED (128a in FIG. 3) The orientation angle of the LED (128a in Fig. 3) can be widened.

7A, the light emitted from the LED 128a has a predetermined directivity angle, and the light emitted from the LED 128a passes through the air gap A and the diffusion plate Some light is refracted in the process of being incident on the diffusion plate 126 having a narrow directivity angle C as compared with a certain directivity angle B of the LED 128a.

7B, when the IMM tape 200 is positioned between the LED 128a and the diffusion plate 126, the light emitted from the LED 128a passes through the diffusion plate 126 without significant refraction , And transmits the diffusion plate 126 as it is with a constant light directing angle B emitted from the LED 128a.

This is to improve the light directing angle B of the LED 128a by placing the IMM tape 200 on the LED 128a.

Table (2) below shows the experimental results of measuring the directivity angle and luminance in Figs. 7A and 7B.

Referring to Table 2, the directivity angle C of the light emitted from the LED 128a and passing through the diffuser plate 126 when the air gap A exists between the LED 128a and the diffuser plate 126, The directivity angle B of the light that is emitted from the LED 128a and transmitted through the diffusion plate 126 is set to be 105% by placing the IMM tape 200 between the LED 128a and the diffusion plate 126, %. ≪ / RTI >

As described above, when the directivity angle B of the light emitted from the LED 128a is widened, if the same luminance is to be achieved, the number of the LEDs 128a can be reduced, And the increase in power consumption can be solved.

Further, as the light directing angle B becomes wider as described above, the LED mura phenomenon occurs in which a dark portion in which the light emitted from the LED 128a is not superimposed and mixed in the region between the neighboring LEDs 128a is generated Can be prevented.

Also, the luminance of light emitted from the LED 128a is also improved. That is, if the luminance measured by the LED 128a when the air gap A exists between the LED 128a and the diffusion plate 126 and transmitted through the diffusion plate 126 is 100%, the LED 128a The brightness measured by the light emitted from the LED 128a and transmitted through the diffusion plate 126 is increased to 115% by locating the IMM tape 200 between the light emitting diode 126a and the diffusion plate 126. [

This also improves the light efficiency of the liquid crystal display device and can prevent the problem of improving the power consumption of the liquid crystal display device.

The IMM tape 200 is made of an acrylic resin or a silicone resin and has a thickness of 50 to 70 lb./ft. Import ³ hardness of gatneunde a certain elasticity, such IMM tape 200 has an elastic force of the plurality of LED (128a), and a diffusion plate 126, by being interposed between, presses, etc. is applied also IMM tape 200, the pressure from the outside The pressure externally applied is relieved.

Therefore, the mechanical reliability of the liquid crystal display device is improved.

8A to 8B are cross-sectional views schematically showing a part of a modular view of a liquid crystal display device according to a second embodiment of the present invention.

As shown in the figure, the IMM tape 200 is positioned above the LED assemblies 128 and the diffusion plate 126 is disposed on the IMM tape 200 .

The optical sheet 127 and the liquid crystal panel 110 are sequentially stacked on the diffusion plate 126.

One side of the IMM tape 200 is in contact with a plurality of LEDs 128a mounted on the PCB 128b of the LED assembly 128 and the other side of the IMM tape 200 is in contact with the diffusion plate 126 .

8A, when one surface of the IMM tape 200 is brought into contact with the LED 128a and the other surface of the IMM tape 200 is brought into contact with the diffusion plate 126, a plurality of LEDs 128a A gap may be generated between the IMM tape 200 and the LED 128a due to a process error in the process of mounting on the PCB 128b.

When the LED 128a and the IMM tape 200 are spaced apart from each other, color discrepancy may occur between the LED 128a and the IMM tape 200 in a region where no separation occurs.

Accordingly, the IMM tape 200 and the plurality of LEDs 128a are formed so as to overlap each other.

That is, the IMM tape 200 is made of an acrylic resin or a silicone resin and has a thickness of 50 to 70 lb./ft. ³ so that a portion of the IMM tape 200 is formed to surround and surround the side edges of the plurality of LEDs 128a.

In order to form the IMM tape 200 to overlap with the plurality of LEDs 128a, the IMM tape 200 is placed on the LED 128a and then the LED 128a is removed from the top of the IMM tape 200 The IMM tape 200 and the LED 128a can be formed to overlap with each other.

The thickness of the IMM tape 200 is preferably 0.5 to 2.5 mm. The thickness of the IMM tape 200 may be formed as described above so as to ensure reliability by thermal expansion of the diffusion plate 126. So that the assembly process error of the LED assembly 128 can be prepared.

8B, when the diffusion plate support 160 is provided to prevent the diffusion plate 126 from being sagged, the IMM tape 200 may be formed by removing the portion where the diffusion plate support 160 is formed You may.

For example, the IMM tape 200 may be divided into a plurality of LED modules corresponding to the respective LED assemblies 128.

As described above, in the liquid crystal display device of the present invention, the IMM tape 200 is interposed between the LED 128a and the diffuser plate 126 in the direct light type liquid crystal display device, so that the light emitted from the LED 128a And the air gap (A in FIG. 7A) is removed through the IMM tape 200, thereby minimizing the light loss.

As a result, the light efficiency of the liquid crystal display device is improved, and the problem of improving the power consumption of the liquid crystal display device can be prevented.

In addition, the light directing angle of the LED 128a (B in FIG. 7B) can be widened. If the same luminance is to be achieved, the number of the LEDs 128a can be reduced, The increase in power consumption can be eliminated, and LED mura phenomenon can be prevented.

In the above description, the IMM tape 200 according to the present invention can be utilized as a liquid crystal display device. However, the IMM tape 200 can be applied to a sidelight type. In this case, a light guide plate (not shown) It can be further interposed on the reflection plate 122 and the IMM tape 200 can be positioned between the LED 128a and the light guide plate (not shown).

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

110: liquid crystal panel,
122: reflector
126: diffusion plate,
127: Optical sheet
128: LED assembly (128a: LED, 128b: PCB)
150: cover bolt
200: IMM tape

Claims (6)

Positioning a reflector;
Positioning an LED assembly comprising a PCB on which a plurality of LEDs and a plurality of LEDs are mounted on the reflector;
Positioning an index matching material tape (IMM) interposed over the LED assembly;
Positioning a diffuser plate over the IMM tape;
Positioning an optical sheet over the diffuser plate;
Positioning the liquid crystal panel over the plurality of optical sheets
/ RTI >
The IMM tape has a refractive index of 1.4 to 1.53,
The IMM tape has a certain elastic force,
The upper surface of the LED assembly is pressed and the pressure is applied from the upper part of the IMM tape toward the LED assembly so that the IMM tape overlaps with a part of the LED to form a side surface of the LED. Way.
The method according to claim 1,
The IMM tape has a thickness of 50 to 70 lb./ft. ^{3 &} gt ;.
The method according to claim 1,
Wherein the IMM tape has a thickness of 0.5 to 2.5 mm.
The method of claim 3,
Wherein one side of the IMM tape is in contact with the LED, and the other side of the IMM tape is in contact with the diffusion plate.

delete The method according to claim 1,
And a diffusion plate support for preventing deflection of the diffusion plate, wherein the portion of the IMM tape where the diffusion plate support is formed is separated and separated into a plurality of portions.

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