KR20120020668A - Multi-light guide sheet and liquid crystal display device including the same - Google Patents

Abstract

PURPOSE: A complex optical sheet and a liquid crystal display device with the same are provided to increase the optical efficiency of a backlight unit. CONSTITUTION: A light source is located in a lower part of a liquid crystal panel. A complex optical sheet(200) is placed on an upper part of the light source. A prism peak is formed on one side of a light concentrating layer which faces the liquid crystal panel. A diffusion layer with a haze component is formed on the other side of the light concentrating layer. A reflecting plate(125) is located in a lower part of the complex optical sheet.

Description

Multi-light guide sheet and liquid crystal display device including the same}

The present invention relates to a liquid crystal display device, and more particularly, to a composite optical sheet having improved light efficiency and viewing angle characteristics.

In line with the recent information age, the display field has also been rapidly developed, and a liquid crystal display device (FPD) is a flat panel display device (FPD) having advantages of thinning, light weight, and low power consumption. LCD, plasma display panel device (PDP), electroluminescence display device (ELD), field emission display device (FED), etc. : It is rapidly replacing CRT.

Among them, LCDs are excellent in moving image display and are most actively used in notebooks, monitors, TVs, etc. due to high contrast ratio. The LCDs are devices that do not have their own light emitting elements. It requires a light source.

Accordingly, a backlight unit having a light source is provided on a rear side of the backlight unit to irradiate light toward the front of the liquid crystal panel, thereby realizing an image of identifiable luminance.

Meanwhile, a general backlight unit is classified into a side light method and a direct type method according to an arrangement of light sources. The side light method is a structure in which one or a pair of light sources is disposed at one side of the light guide plate. It has, or two or two pairs of light sources have a structure arranged on each side of the light guide plate, the direct type has a structure in which several light sources are arranged under the optical sheet.

Here, the side light method is easier to manufacture than the direct type method, and has the advantages of lighter weight and lower power consumption than the direct type.

1 is an exploded perspective view of a backlight unit of the side light method, Figures 2a to 2b is a photograph showing a conventional problem.

As shown in FIG. 1, the general backlight unit 20 includes a lamp 29a which is a light source, a light guide plate 23 having at least one side surface facing the lamp 29a, and positioned on the same plane as the lamp 29a. (23) It is composed of a diffusion plate 27 and a plurality of optical sheets 21 to be seated on the top.

Further, a reflector 25 for reflecting light exiting to the lower surface of the light guide plate 23 is further formed below the light guide plate 23, and a lamp guide 29b for guiding the lamp 29a is further provided.

Here, in the plurality of optical sheets 21, the light collecting sheet 21b and the second diffusion sheet 21c are sequentially positioned to implement the first diffusion sheet 21a and the high brightness.

In this case, one light collecting sheet 21b may be configured and used, but a plurality of light collecting sheets 21b may be overlapped to realize high brightness.

However, the light collecting sheet 21b is accompanied by a light loss due to side lobes, which results in a decrease in light efficiency and a decrease in viewing angle characteristics.

That is, the light is refracted by the light collecting sheet 21b in an unnecessary direction and is lost without being incident on the front liquid crystal panel (not shown) positioned above the backlight unit 20, so that light leakage occurs in this region.

Therefore, in order to solve this problem, a reflective polarizing sheet (not shown) or a diffusion sheet (not shown) having a recycling effect of light should be further configured on the light collecting sheet 21b.

In particular, the light passing through the light collecting sheet 21b generates a portion where the luminance distribution is rapidly changed according to the viewing angle. Due to such optical characteristics, the light collecting sheet 21b is formed at a viewing angle at which the luminance distribution is rapidly changed. So-called spectrum muras or hot bands appear in which boundaries of contrast occur.

FIG. 2A is a photograph showing a spectral mura, and FIG. 2B is a photograph showing a hot band.

The spectral mura is generated as the light passing through the light collecting sheet 21b is diffused. In order to prevent the occurrence of the spectral mura, hot band is generated when the diffusion by the light collecting sheet 21b is made less.

Such spectral mura and hot bands cause deterioration of the image quality of the liquid crystal display. In order to solve this problem, a plurality of optical sheets 21 are further stacked on the light collecting sheet 21b to reduce the luminance change.

However, when the number of the optical sheets 21 stacked in this manner increases, the image quality is improved, but the production cost of the backlight unit 20 is increased, and the work process time is increased in the modularization process of the liquid crystal display device, thereby decreasing the efficiency of the process. As a result, the production cost increases.

In particular, despite efforts to manufacture a liquid crystal display device in a light weight and thin form, as the components of the backlight unit 20 which have the greatest influence on the overall thickness of the liquid crystal display device become too large, Lightweight is hindered.

Therefore, research is being actively conducted to develop a backlight unit 20 capable of realizing excellent image quality and improving process efficiency without using many optical sheets.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to improve the light efficiency of the backlight unit and to realize the display screen of the liquid crystal display device using the same in a high quality with uniform luminance.

In addition, the second object of the present invention is to reduce the assembly time and the material cost in the modularization process of the liquid crystal display device while realizing the light weight and thinness of the liquid crystal display device.

In order to achieve the above object, the present invention is a liquid crystal panel; A light source positioned under the liquid crystal panel; A composite optical sheet seated on the light source, the light collecting layer having a prism acid formed on one surface facing the liquid crystal panel, and a diffusion layer having a haze component formed on the other surface opposite to one surface on which the prism acid is formed; Provided is a liquid crystal display including a reflector disposed under the composite optical sheet.

In this case, the composite optical sheet includes a support layer made of polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), and the like, wherein the prism acid is arranged to protrude from the support layer, and the light collecting layer has a refractive index of 1.57 to 1.58.

The corners constituting the vertices of the prism peaks have an angle of 80 to 90 degrees, and the spacing of the prism peaks is 48 to 50 µm.

Here, the prism acid is regularly formed in different sizes, and the haze component of the diffusion layer is 15 to 30%.

In this case, the diffusion layer includes a bead or a fine pattern is formed on a lower surface, and a diffusion plate is formed under the composite optical sheet.

In addition, the light source is one selected from a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (External Electrode Fluorescent Lamp), and a light emitting diode (LED). The light guide plate is formed on the reflective plate, and the light source is arranged on one side or both sides of the light guide plate.

In addition, the present invention and the support layer; A light collecting layer formed on one surface of the support layer and protruding so that a plurality of prism acids are arranged adjacent to each other on the support layer; It is formed on the other surface of the support layer, and provides a composite optical sheet including a diffusion layer having a haze component of 15 to 30%.

As described above, according to the present invention by forming a prism acid and having a composite optical sheet having a haze component, high brightness can be realized, and side lobes, spectral mura, and hot bands can be prevented from occurring. It works.

This improves the light efficiency and has the effect of improving the viewing angle characteristics.

In addition, the liquid crystal display device can realize a light weight and a thin shape, and can manufacture the backlight unit 120 at a lower cost and can reduce the working time in the modularization process of the liquid crystal display device, thereby improving the efficiency of the process. It has an effect.

1 is an exploded perspective view of a side light backlight unit.
Figure 2a to 2b is a photograph showing a conventional problem.
3 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.
4 is an exploded perspective view of the backlight unit of FIG. 2;
5 is a sectional view schematically showing the structure of a composite optical sheet;
Figure 6 is a graph showing the appearance of the side lobe and the luminance distribution according to the viewing angle of the backlight unit using the composite optical sheet of the present invention.
7 is a photograph when driving the liquid crystal display using the composite optical sheet according to an embodiment of the present invention.
8 is a cross-sectional view schematically showing another embodiment of the present invention.

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

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

As shown, the liquid crystal display device includes a liquid crystal panel 110 and a backlight unit 120, a support main 130, a cover bottom 150, and a top for modularizing the liquid crystal panel 110 and the backlight unit 120. It consists of a cover 140.

Looking at each of them in detail, first, the liquid crystal panel 110 plays a key role in image expression, and includes the first and second substrates 112 and 114 bonded to each other with the liquid crystal layer interposed therebetween. .

In this case, under the premise of an active matrix method, although a plurality of gate lines and data lines intersect on the inner surface of the first substrate 112, which is commonly referred to as a lower substrate or an array substrate, pixels are defined. Thin film transistors (TFTs) are provided at each intersection to be connected one-to-one with the transparent pixel electrodes formed in each pixel.

In addition, an inner surface of the second substrate 114, called an upper substrate or a color filter substrate, includes color filters of R, G, and B colors, and the gate lines and the data lines. In addition, a black matrix covering a non-display element such as a thin film transistor is provided. In addition, a transparent common electrode covering them is provided.

In addition, the printed circuit board 117 is connected through at least one edge of the liquid crystal panel 110 via a connection member 116 such as a flexible circuit board, thereby supporting the side or cover of the support main 130 in the modularization process. (150) It is folded to the back and adheres.

In the liquid crystal panel 110 having the above-described structure, a signal for turning on / off the thin film transistor is sequentially scanned and applied to the gate line, so that the image signal of the data line is applied to the pixel electrode of the selected pixel. When is transferred, the liquid crystal molecules between the first and second substrates 112 and 114 are driven by the electric field therebetween, and various images can be displayed by the change in the transmittance of light.

In this case, polarizing plates (not shown) for selectively transmitting only specific polarized light are attached to outer surfaces of the first and second substrates 112 and 114.

Although not clearly shown in the drawings, the upper and lower alignment layers for determining the initial molecular alignment direction of the liquid crystal are interposed between the two substrates 112 and 114 of the liquid crystal panel 110 and the liquid crystal layer, and filled therebetween. Seal patterns are formed along edges of both substrates 112 and 114 to prevent leakage of the liquid crystal layer.

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

The backlight unit 120 includes a lamp 129a, a reflector plate 125, a light guide plate 123 seated on the reflector plate 125, and a diffuser plate 121 and a composite optical sheet 200 interposed therebetween. Include.

The lamp 129a described above is located at one side of the light guide plate 123 to face the light incident part of the light guide plate 123, and the lamp 129a is guided to the outside by the lamp guide 129b.

In this case, the light guide plate 123 evenly spreads the light incident from the lamp 129a to the inside of the light guide plate 123 by propagating the light inside the light guide plate 123 by a plurality of total reflections to provide a surface light source to the liquid crystal panel 110. do.

In addition, the reflector plate 125 is positioned on the rear surface of the light guide plate 123 to improve the brightness of the light by reflecting the light passing through the rear surface of the light guide plate 123 toward the liquid crystal panel 110.

In addition, the diffusion plate 121 and the composite optical sheet 200 on the light guide plate 123 diffuse or condense the light passing through the light guide plate 123 so that a more uniform surface light source is incident on the liquid crystal panel 110. We will discuss this in more detail later.

Accordingly, the light emitted from the lamp 129a is incident into the light guide plate 123 through the light incident part of the light guide plate 123, and the incident light passes through the light guide plate 123 by a plurality of total reflections. Spread evenly over a wide area and processed into a uniform high-quality light while passing through the diffusion plate 121 and the composite optical sheet 200, and then enters the liquid crystal panel 110, by which the liquid crystal panel 110 is finally high brightness Can display an image.

The liquid crystal panel 110 and the backlight unit 120 are modularized through the top cover 140, the support main 130, and the cover bottom 150. The top cover 140 is the top and side surfaces of the liquid crystal panel 110. A rectangular frame having a cross section bent in a shape of “a” so as to cover an edge thereof is configured to open an entire surface of the top cover 140 to display an image implemented in the liquid crystal panel 110.

In addition, the cover bottom 150 on which the liquid crystal panel 110 and the backlight unit 120 are mounted, and which is the basis for assembling the entire apparatus of the liquid crystal display device, has a rectangular plate shape and has one side edge vertically bent at a predetermined height. do.

A support main 130 having a rectangular frame shape seated on the cover bottom 150 and surrounding 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.

In this case, the top cover 140 may also be referred to as a case top or a top case, and the support main 130 may also be referred to as a guide panel, a main support, or a mold frame, and the cover bottom 150 may be referred to as a bottom cover or a lower cover. It is also built.

The liquid crystal display device of the present invention is reduced in overall thickness compared to the conventional liquid crystal display device, because the thickness of the backlight unit 120 that has the greatest effect on the thickness of the liquid crystal display device compared with the conventional.

That is, the conventional backlight unit 20 of FIG. 1 includes a diffusion plate 27 of FIG. 1, a first and a second diffusion sheets 21a and 21c of FIG. 1, and a light collecting sheet on the light guide plate 23 of FIG. 1. A plurality of optical sheets (21 of FIG. 1), such as (21b of FIG. 1), are used to overlap a plurality of light collecting sheets (21b of FIG. 1), or a side lobe and a spectral mura or hot band in order to realize higher brightness. In order to alleviate the change in luminance caused by the light collecting sheet (21b of FIG. 1) is further laminated a plurality of optical sheets, the present invention, the light guide plate 123, the diffusion plate 121 and the composite optical sheet 200 end Since only two optical sheets are located, the thickness of the backlight unit 120 is reduced compared to the conventional.

Accordingly, the liquid crystal display device of the present invention can realize a light weight and a thin shape, and many components of the backlight unit 120 have increased the working process time in the modularization process of the liquid crystal display device, thereby reducing the efficiency of the process. Compared to this, the working time can be shortened, improving the efficiency of the process.

In addition, it is possible to manufacture the backlight unit 120 at a lower cost than the conventional, in particular, the present invention can implement a high brightness through the composite optical sheet 200, the side lobe, spectrum mura and hot band is generated Can be prevented.

That is, the present invention can provide an efficient backlight unit 120 with excellent performance.

4 is an exploded perspective view of the backlight unit of FIG. 3, and FIG. 5 is a cross-sectional view schematically illustrating a structure of the composite optical sheet.

As shown in FIG. 4, the backlight unit 120 includes a white or silver reflecting plate 125 seated on the cover bottom 150 of FIG. 3, and a lamp 129a which is a light source arranged along the longitudinal direction of one edge thereof. ), A light guide plate 123 positioned on the same plane as the lamp 129a and seated on the reflector 125, and having at least one side facing the lamp 129a, and a diffusion plate 121 seated on the light guide plate 123. ) And the composite optical sheet 200.

In addition, a lamp guide 129b for guiding the lamp 129a is further provided. The lamp guide 129b surrounds the upper and lower sides and the outside of the lamp 129a in a state in which the inner side toward the light guide plate 123 is opened, and the lamp ( In addition to the protection of 129a, light is concentrated in the direction of the light guide plate 123.

In this case, as the light source, the lamp 129a may be a fluorescent lamp such as a cold cathode fluorescent lamp or an external electrode fluorescent lamp. Alternatively, a light-emitting diode lamp other than the fluorescent lamp may be used as the lamp 129a, and the lamp guide 129b may be deleted when the light-emitting diode lamp is used.

The light guide plate 123 is made of a plastic material such as polymethylmethacrylate (PMMA), which is one of transparent materials capable of transmitting light, or is made of polycarbonate (PC). It is manufactured in a flat type. Here, PMMA is an acrylic resin, which has excellent transparency, weather resistance, and colorability, and induces light diffusion when light is transmitted.

The reflector 125 is positioned under the light guide plate 123 to improve the brightness of the light by reflecting the light passing through the lower surface of the light guide plate 123 toward the liquid crystal panel (110 of FIG. 3).

In addition, the diffusion plate 121 on the upper part of the light guide plate 123 diffuses the light passing through the light guide plate 123, thereby preventing the light from being partially concentrated. The diffusion plate 121 serves to adjust the direction of light so that the light propagates toward the composite optical sheet 200 positioned on the diffusion plate 121.

The composite optical sheet 200 on the diffuser plate 121 diffuses or condenses the light passing through the diffuser plate 121 to inject a more uniform surface light source into the liquid crystal panel (110 of FIG. 3). The 200 has a haze component to further adjust the direction of the light while further dispersing the light incident through the diffuser plate 121, and a light collecting layer 213 of FIG. 5 is formed to emit light. The light is focused in the direction of the panel 110 (see FIG. 3).

As a result, the composite optical sheet 200 may include a plurality of optical sheets (21 of FIG. 1) including the first and second diffusion sheets 21a and 21c of FIG. 1 and the light collecting sheet 21b of FIG. 1. Can be replaced.

In particular, it is possible to mitigate the luminance change due to side lobes, spectral mura and hot bands, it is not necessary to further stack the separate optical sheets on the composite optical sheet 200.

Here, referring to FIG. 5, the composite optical sheet 200 of the present invention will be described in more detail. The composite optical sheet 200 according to the exemplary embodiment of the present invention transmits light passing through the diffusion plate 121 to the liquid crystal panel (FIG. 3). By diffusing and condensing toward 110), the light efficiency is improved compared to the conventional ones having the first and second diffusion sheets 21a and 21c of FIG. 1 and the light collecting sheet 21b of FIG.

As shown in FIG. 5, the composite optical sheet 200 includes a support layer 211 formed of a transparent polymethylmethacrylate (PMMA) that transmits light, polyethylene terephthalate (PET), and the like, and an upper surface of the support layer 211. The light collecting layer 213 for condensing light and the lower surface of the support layer 211 is composed of a diffusion layer 215 for diffusing light.

The light collecting layer 213 formed on the upper surface of the support layer 211 is formed to collect light. The light collecting layer 213 is arranged adjacent to each other in a band shape along the longitudinal direction of the support layer 211 so that peaks and valleys are repeated. A plurality of prismatic mountains 213a in the form are arranged in a row to protrude from the support layer 211.

This prism mountain 213a has first and second inclined surfaces that are inclined at a predetermined angle from the vertex.

Due to the prism acid 213a, the composite optical sheet 200 improves the light condensing efficiency of the liquid crystal panel 110 (see FIG. 3). This has a brightness raising effect.

At this time, the angle of the corner which forms the apex of the prism mountain 213a is 80-90 degrees.

That is, at this time, the first and second inclined surfaces of the prism mountain 213a are formed to be inclined by about 45 to 50 degrees from the support layer 211, respectively, so that the corners formed by the first and second inclined surfaces form 80 to 90 degrees. will be.

Here, the refractive index of the light collecting layer 213 of the composite optical sheet 200 is preferably 1.57 to 1.58.

Since the brightness of the composite optical sheet 200 is reduced by the diffusion layer 215, the refractive index of the light collecting layer 213 has a refractive index of 1.57 to 1.58, thereby condensing the light passing through the composite light collecting sheet 200. This is to compensate for the luminance lowered by the diffusion layer 215 and further increase the luminance.

Here, the light collecting layer 213 may be formed integrally with the support layer 211 or made of different materials. When the light collecting layer 213 is made of different materials, the light collecting layer 213 may be formed of incident light such as acrylic, urethane, polyester, or the like. Any material that can enhance the light collecting property is possible.

In addition, the diffusion layer 215 formed on the opposite side of the support layer 211 on which the light collecting layer 213 is formed, that is, the lower surface, is configured to have a haze characteristic of 15 to 30%, wherein the haze characteristic is a material in which light is transparent. Depending on the type of material, the light is diffused depending on the material's inherent properties as well as the appearance of opaque cloudy appearance. The haze characteristic value can be measured according to Equation (1) below.

Haze (%) = (total amount of light delivered-straight light amount / total amount of light transmitted) X 100 ......... Equation (1)

In particular, the diffusion layer 215 of the composite optical sheet 200 of the present invention preferably has a haze characteristic of 27%.

As such, in order for the diffusion layer 215 to have haze characteristics, the diffusion layer 215 may include light diffusing components such as beads 215a, or may not include the beads 215a and may have fine patterns on the lower surface thereof. It may be configured to form.

At this time, the bead 215a is configured to be included in the acrylic resin, the bead (not shown) has a feature that can prevent the light is partially concentrated by dispersing the light incident on the support layer 211.

In addition, the diffusion layer 215 that does not include the bead 215a has a feature that can adjust the light scattering angle according to the shape of the fine pattern (not shown), the fine pattern (not shown) is an elliptical pattern (elliptical pattern) , Polygonal pattern, etc., and the hologram pattern is used to refract the incident light by the interference pattern in an asymmetrical direction so that the collected light diffuses at a more inclined angle. You can do that.

As a result, light is dispersed through the diffusion layer 215 to prevent the light from being partially concentrated.

In particular, the composite optical sheet 200 of the present invention can minimize light leakage due to side lobes through the diffusion layer 215. This improves light efficiency and improves viewing angle characteristics.

In detail, the light incident on the composite optical sheet 200 is refracted to the lower surface of the composite optical sheet 200 when the light is incident on the loss region of the prism acid 213a of the light collecting layer 213. It is lost without being incident to the front liquid crystal panel (110 in FIG. 3), and light leakage occurs in this region.

 As a result, the light efficiency is reduced and the viewing angle characteristic is lowered.

However, in the composite optical sheet 200 of the present invention, the diffusion layer 215 is formed on the lower surface of the composite optical sheet 200, so that light is incident on the loss region of the prism acid 213a, so that the composite optical sheet 200 By dispersing the light refracted to the lower surface, it is possible to prevent the light leakage caused by the side lobe.

6 is a graph illustrating a luminance distribution according to a view of a side lobe generated and a viewing angle of a backlight unit using the composite optical sheet of the present invention.

Referring to the graph, it can be seen that A has bright regions on both sides with respect to the center portion, which is a side lobe region (C).

On the contrary, B is a graph showing the luminance distribution according to the viewing angle of the backlight unit using the composite optical sheet of the present invention, and it can be seen that the side lobe region C is canceled compared to A.

In addition, it can be seen from the graph above that the occurrence of hot bands is alleviated.

That is, referring to the graph of FIG. 6, in the case of A, the luminance decreases rapidly at a viewing angle around about 20 degrees, while the composite optical sheet B of the embodiment shows a gentle change in luminance.

As described above, since a hot band is generated by a sudden change in luminance, when using a composite optical sheet showing a smooth change in luminance, such as B, hot bands are alleviated, thereby improving image quality. It can be implemented.

FIG. 7 is a photograph of a liquid crystal display using a composite optical sheet according to an exemplary embodiment of the present invention, and it can be seen that light leakage, spectrum mura, and hot band do not appear on a screen.

Accordingly, the light emitted from the lamp 129a is guided to the light guide plate 123 by the lamp guide 129b, and is then refracted in the direction of the liquid crystal panel (110 in FIG. 3), and the diffuser plate 121 and the composite optical sheet ( While passing through the 200, it is processed to a high quality of uniform brightness and is incident on the liquid crystal panel (110 in FIG. 3), whereby the liquid crystal panel (110 in FIG. 3) displays an image to the outside.

That is, the composite optical sheet 200 of the present invention diffuses or condenses the light passing through the diffusion plate 121 so that a more uniform surface light source is incident on the liquid crystal panel (110 of FIG. 3). Therefore, the composite optical sheet 200 replaces a plurality of optical sheets (21 of FIG. 1) including the existing first and second diffusion sheets 21a and 21c of FIG. 1 and the light collecting sheet 21b of FIG. can do.

As a result, the backlight unit 120 may be manufactured at a lower cost, and the working process time may be reduced in the modularization process of the liquid crystal display, thereby improving the efficiency of the process.

In addition, in the composite optical sheet 200 of the present invention, as shown in FIG. 8, the interval P of the prism mountains 213a of the light collecting layer 213, that is, the interval P between the first and second inclined surfaces is regularly. It may be formed differently.

In the process of interposing the composite optical sheet 200 on the diffuser plate 121, the dummy sheet (not shown) having an adhesive component is attached and then removed for protection of the prism acid 213a. This is to prevent the adhesive component of the (not shown) from remaining as foreign matter on the upper portion of the prism acid 213a.

That is, when the size of the prism acid 213a is formed regularly differently, the contact area between the dummy sheet (not shown) and the prism acid 213a attached to the composite optical sheet 200 can be minimized.

At this time, it is preferable that the interval between the prism peaks 213a is formed regularly differently so that the angle of the corner formed by the first and second inclined surfaces of the prism peaks 213a is 90 ° within a range of not exceeding 48 to 50 μm. .

In the above description, a side light method is used as a liquid crystal display device in which the composite optical sheet 200 according to the present invention may be used for convenience, but this may be applied to a direct type method, in which case the light guide plate 123 is removed. The plurality of lamps 129a are arranged side by side on the reflecting plate 125, and the diffusion plate 121 and the composite optical sheet 200 according to the embodiment of the present invention may be interposed therebetween.

As described above, the liquid crystal display of the present invention includes a composite optical sheet 200 having a prism acid 213a and having a haze component, whereby a large number of components of the backlight unit 120 are provided. In the modular process of the process, the working process time is increased to reduce the working process time compared to the existing process efficiency, thereby improving the efficiency of the process.

In addition, the backlight unit 120 can be manufactured at a lower cost, and the liquid crystal display device can realize a light weight and a thin film.

In particular, the present invention can implement high brightness through the composite optical sheet 200, it is possible to prevent the generation of side lobes, spectral mura and hot band.

This improves the light efficiency and has the effect of improving the viewing angle characteristics.

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: composite optical sheet, 211: support layer, 213: light collecting layer, 213a: prism acid
215: diffusion layer, 215a: beads

Claims (12)

A liquid crystal panel;
A light source positioned under the liquid crystal panel;
A composite optical sheet seated on the light source, the light collecting layer having a prism acid formed on one surface facing the liquid crystal panel, and a diffusion layer having a haze component formed on the other surface opposite to one surface on which the prism acid is formed;
Reflector located under the composite optical sheet
Liquid crystal display comprising a.
The method of claim 1,
The composite optical sheet includes a support layer made of polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), which is a thermoplastic resin, and the prism acid is arranged to protrude from the support layer.
The method of claim 2,
The light collecting layer has a refractive index of 1.57 to 1.58.
The method of claim 2,
And a corner forming the vertex of the prism acid has an angle of 80 to 90 degrees.
The method of claim 2,
The prism acid spacing is 48 ~ 50㎛ liquid crystal display device.
The method of claim 5, wherein
And the prism acid is regularly formed in a different size.
The method of claim 2,
The haze component of the diffusion layer is a liquid crystal display device of 15 to 30%.
The method of claim 7, wherein
The diffusion layer includes a bead or a fine pattern formed on a lower surface of the liquid crystal display device.
The method of claim 1,
And a diffuser plate under the composite optical sheet.
The method of claim 1,
The light source is a liquid crystal display device selected from a Cold Cathode Fluorescent Lamp (CCFL), an External Electrode Fluorescent Lamp, and a Light Emitting Diode (LED).
The method of claim 1,
A light guide plate is formed on the reflective plate, and the light source is arranged on one side or both sides of the light guide plate.
A support layer;
A light collecting layer formed on one surface of the support layer and protruding so that a plurality of prism acids are arranged adjacent to each other on the support layer;
Diffusion layer formed on the other surface of the support layer, having a haze component of 15 to 30%
Composite optical sheet comprising a.

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