KR20060031485A - Reflective polarizing film, display apparatus having the same and method of manufacturing the same - Google Patents

Abstract

A reflective polarizing member having a light diffusing function, a display device having the same, and a manufacturing method thereof are disclosed. The reflective polarizing member includes a liquid crystal film and a diffusion layer. The liquid crystal film is composed of liquid crystal twisted in a predetermined direction to reflect light parallel to the twisting direction of the liquid crystal and transmit the remaining light. The diffusion layer is attached to the liquid crystal film to diffuse the light. Therefore, the luminance uniformity can be improved while preventing the reflection of the reflective polarizing member.

Description

REFLECTIVE POLARIZING FILM, DISPLAY APPARATUS HAVING THE SAME AND METHOD OF MANUFACTURING THE SAME}

1 is a cross-sectional view of a reflective polarizing member according to an exemplary embodiment of the present invention.

2 is a cross-sectional view showing in detail the liquid crystal film shown in FIG.

3 is a view illustrating in detail the liquid crystal layer illustrated in FIG. 2.

4 is a cross-sectional view of a reflective polarizing member according to another exemplary embodiment of the present invention.

5 is a cross-sectional view of a reflective polarizing member according to another exemplary embodiment of the present invention.

FIG. 6 is a process diagram illustrating a manufacturing process of the reflective polarizing member illustrated in FIG. 1.

7A is a view showing the state of the UV adhesive before curing.

7B is a view showing the state of the UV adhesive after curing.

8 is a cross-sectional view of a display device including the reflective polarizing member illustrated in FIG. 1.

9 is a cross-sectional view of a reflective polarizing member according to still another embodiment of the present invention.

10 is a cross-sectional view of the organic particles shown in FIG. 9.

FIG. 11 is a process diagram illustrating a manufacturing process of the reflective polarizing member illustrated in FIG. 9.

FIG. 12 is a cross-sectional view of a display device including the reflective polarizing member illustrated in FIG. 9.                 

* Description of the symbols for the main parts of the drawings *

101, 500: reflective polarizing member 110: liquid crystal film

111: base layer 112: liquid crystal layer

116: phase difference layer 120, 520: first diffusion layer

130 and 530: second diffusion layer 140 and 540: first UV adhesive

150, 550: second UV adhesive 200: backlight assembly

210: multiple lamps 220: diffuser plate

230: diffusion sheet 240: first prism sheet

250: second prism sheet 300: display unit

310: display panel 320: first polarizing plate

330: second polarizing plate 401, 402: display device

510: diffuse reflection film

The present invention relates to a reflective polarizing member, a display device having the same, and a manufacturing method thereof, and more particularly, to a reflective polarizing member having a light diffusing function, a display device having the same, and a manufacturing method thereof.

As a flat panel display device that displays an image using liquid crystal, it is thinner and lighter than other display devices, has a low driving voltage and low power consumption, and is widely used throughout the industry.

Such a liquid crystal display device requires a light source device for providing separate light because the liquid crystal display panel for displaying an image is a non-light emitting device that does not emit light by itself.

The light source device is a light source that generates light, and is made of a long, cold cylindrical fluorescent lamp (Cold Cathode Fluorescent Lamp (CCFL)). The light source device is largely classified into an edge type and a direct type according to the position of the light source.

In the edge type, one or two light sources are provided on the side of the transparent light guide plate, and the light generated from the light source is reflected multiple times through one side of the light guide plate and is emitted to the liquid crystal display panel. On the other hand, in the direct type, a plurality of light sources are provided directly below the liquid crystal display panel, the front of the light source is provided with a diffusion plate, the back of the light source is provided with a reflecting plate. Therefore, the light emitted from the light source is reflected by the reflecting plate, diffused by the diffusion plate, and then emitted to the liquid crystal display panel.

In the conventional liquid crystal display device, the light source device generates 100% of light, but the light emitted from the liquid crystal display panel has a luminance of about 7% of the light emitted from the light source device. Further, if the luminance uniformity of the light emitted from the light source device is 76.3%, the luminance uniformity of the light emitted from the liquid crystal display panel is reduced to 69.7% than the light emitted from the light source device. Due to the decrease in luminance and the decrease in luminance uniformity, the display quality of the liquid crystal display is degraded.

 Accordingly, it is an object of the present invention to provide a reflective polarizing member having a light diffusing function.

Another object of the present invention is to provide a display device having the above-mentioned reflective polarizing member.

Further, another object of the present invention is to provide a method applied to manufacturing the above-mentioned reflective polarizing member.

Reflective polarizing member according to an aspect of the present invention includes a liquid crystal film and a diffusion layer. The liquid crystal film is made of a liquid crystal twisted in a predetermined direction reflects light parallel to the twisting direction of the liquid crystal and transmits the remaining light. The diffusion layer is attached to the liquid crystal film to diffuse the light.

The reflective polarizing member according to another feature of the present invention includes a diffuse reflection film and a diffusion layer. The diffuse reflection film is made of a plurality of organic particles contained in the polymer resin is stretched in a predetermined direction with the polymer resin to selectively diffuse reflection of light incident by the organic particles. The diffusion layer is attached to the diffuse reflection film to diffuse the light.

According to still another aspect of the present invention, there is provided a display device including: a backlight assembly generating light, a reflective polarizing member provided on an upper portion of the backlight assembly to selectively reflect and polarize the light, and the polarized light provided on the reflective polarizing member It includes a display panel for displaying an image using light.                     

The reflective polarizing member includes a liquid crystal film and a diffusion layer. The liquid crystal film is made of a liquid crystal twisted in a predetermined direction reflects light parallel to the twisting direction of the liquid crystal and transmits the remaining light. The diffusion layer is attached to the liquid crystal film to diffuse the light.

According to still another aspect of the present invention, there is provided a display device including: a backlight assembly generating light, a reflective polarizing member provided on an upper portion of the backlight assembly to selectively reflect and polarize the light, and the polarized light provided on the reflective polarizing member It includes a display panel for displaying an image using light.

The reflective polarizing member includes a diffuse reflection film and a diffusion layer. The diffuse reflection film is made of a plurality of organic particles contained in the polymer resin is stretched in a predetermined direction with the polymer resin to selectively diffuse reflection of light incident by the organic particles. The diffusion layer is attached to the diffuse reflection film to diffuse the light.

In the method of manufacturing a reflective polarizing member according to another aspect of the present invention, the liquid crystal film is made of a liquid crystal twisted in a predetermined direction to form a liquid crystal film that reflects light parallel to the twisting direction of the liquid crystal and transmits the remaining light, the liquid crystal film A diffusion layer for diffusing the light is attached thereto.

In the method of manufacturing a reflective polarizing member according to another aspect of the present invention, by stretching the polymer resin containing a plurality of organic particles in a predetermined direction to form a diffuse reflection film having organic particles of the core shell structure, A diffusion layer for diffusing the light is attached to the diffuse reflection film.                     

According to the reflective polarizing member, the display device having the same, and a manufacturing method thereof, a diffusion layer is added to the reflective polarizing member to prevent the reflection of the reflective polarizing member, and as a result, display quality of the display device can be improved.

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

1 is a cross-sectional view of a reflective polarizing member according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing in detail the liquid crystal film shown in FIG. 1, and FIG. 3 is a view showing the liquid crystal layer shown in FIG. 2 in detail. to be.

Referring to FIG. 1, the reflective polarizing member 101 according to an exemplary embodiment of the present invention may include a liquid crystal film 110, a first diffusion layer 120, a second diffusion layer 130, and a first ultraviolet (UV) adhesive 140. ) And a second UV adhesive 150.

The first diffusion layer 120 is provided under the liquid crystal film 110 to diffuse light incident on the liquid crystal film 110. The first diffusion layer 120 is attached to the bottom surface of the liquid crystal film 110 by the first UV adhesive 140. The second diffusion layer 130 is provided on the liquid crystal film 110 to diffuse the light emitted from the liquid crystal film 110. The second diffusion layer 130 is attached to the upper surface of the liquid crystal film 110 by the second UV adhesive 150. The first and second diffusion layers 120 and 130 have a thickness of 10 μm to 300 μm, and as an example of the present invention, the first and second diffusion layers 120 and 130 have a thickness of 34 μm.

The first and second diffusion layers 120 and 130 are made of a material having a low thermal expansion rate and a low water absorption rate in order to protect the liquid crystal film 110 from heat or moisture. In the present invention, the first and second diffusion layers 120 and 130 are made of polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol or polynorbornene. Can be. Accordingly, the first and second diffusion layers 120 and 130 may prevent the liquid crystal film 110 from moving due to heat or moisture.

Diffusion agents for diffusing the light are added to the first and second diffusion layers 120 and 130. In the present invention, the diffusion agent may include a silicon diffusion agent, a magnesium diffusion agent or a calcium oxide diffusion agent. Accordingly, luminance uniformity of light passing through the first and second diffusion layers 120 and 130 may be improved. In addition, the first and second diffusion layers 120 and 130 further include a cationic surfactant for preventing the liquid crystal film 110 from being charged.

The first and second UV adhesives 140 and 150 are cured by ultraviolet rays to attach the first and second diffusion layers 120 and 130 to the bottom and top surfaces of the liquid crystal film 110, respectively. In the present invention, the first and second UV adhesives (140, 150) is a photopolymerizable monomer of the acrylate-based, epoxy acrylate-based, polyester acrylate-based or urethane acrylate-based oligomer, acetophenone-based, benzophene Non- or thioxanthone type photopolymerization initiator is included. The first and second UV adhesives 140 and 150 will be described in more detail later with reference to FIGS. 7A and 7B.

As shown in FIG. 2, the liquid crystal film 110 includes a base layer 111, a liquid crystal layer 112, and a retardation layer 116. In the present invention, the base layer 111 is made of a polyethylene terephthalate system.

The liquid crystal layer 112 is provided on the base layer 111 and consists of cholesteric liquid crystal to circularly polarize the light incident on the liquid crystal film 110.

The liquid crystal layer 112 includes a first liquid crystal layer 112a for circularly polarizing light in the red wavelength band, a second liquid crystal layer 112b for circularly polarizing light in the green wavelength band, and a third liquid crystal for circularly polarizing light in the blue wavelength band. Layer 112c. The first to third liquid crystal layers 112a, 112b, and 112c are sequentially formed on the base layer 111.

The first liquid crystal layer 112a is attached to the upper surface of the base layer 111 by the first adhesive 113, and the second liquid crystal layer 112b is the first liquid crystal by the second adhesive 114. It is attached to the top surface of layer 112a. The third liquid crystal layer 112c is attached to the top surface of the second liquid crystal layer 112b by the third adhesive 115.

Meanwhile, the first, second and third liquid crystal layers 112a, 112b, and 112c have a cholesteric liquid crystal and a vertical alignment (VA) liquid crystal mixed in a predetermined ratio in a solvent. Consisting of a mixed material containing a UV initiator. Here, the ratio of the cholesteric liquid crystal mixed with the VA liquid crystal mixed in the first, second and third liquid crystal layers 112a, 112b, and 112c to selectively reflect light of different wavelength bands is different. Specifically, the cholesteric liquid crystal and the VA liquid crystal are mixed in a ratio of 8: 2 to the first liquid crystal layer 112a, and the cholesteric liquid crystal and the VA liquid crystal are 7: in the second liquid crystal layer 112b. 3 is mixed, and the cholesteric liquid crystal and the VA liquid crystal are mixed in a ratio of 6: 4 in the third liquid crystal layer 112c.

As shown in FIG. 3, the cholesteric liquid crystal 112-1 has a state in which rod-shaped liquid crystal molecules are twisted spirally as one step of a liquid crystal phase. The cholesteric liquid crystal 112-1 repeats the twist at regular intervals, and the repeated length is referred to as pitch P.

Here, the first, second and third liquid crystal layers 112a, 112b and 112c have different pitches P. The first, second, and third liquid crystal layers 112a, 112b, and 112c have wavelength bands corresponding to a product of the pitch P and the refractive index of the cholesteric liquid crystal 112-1. Therefore, the pitch P increases in the order of the first, second and third liquid crystal layers 112a, 112b and 112c.

The first, second, and third liquid crystal layers 112a, 112b, and 112c strongly reflect light polarized in the same direction as the twisting direction of the cholesteric liquid crystal 112-1, and light of another wavelength band as it is. Pass it through. Therefore, the light reflected by the first, second and third liquid crystal layers 112a, 112b and 112c has a state of right circularly polarized light or left circularly polarized light according to the twisting direction of the cholesteric liquid crystal 112-1, The light transmitted without being reflected has a circularly polarized state opposite to the reflected light.

Thereafter, the light reflected by the first, second and third liquid crystal layers 112a, 112b and 112c is incident to the first, second and third liquid crystal layers 112a, 112b and 112c. As this series of processes is repeated, most of the light eventually passes through the first, second, and third liquid crystal layers 112a, 112b, and 112c with one circularly polarized state.                     

The retardation layer 116 is provided on the third liquid crystal layer 112c. The retardation layer 116 is attached to the upper surface of the third liquid crystal layer 112c by the fourth adhesive agent 117. The retardation layer 116 linearly polarizes the light circularly polarized by the liquid crystal layer 112. Therefore, the light passing through the retardation layer 116 has a P wave component.

In one embodiment of the present invention, the retardation layer 116 is composed of a λ / 4 retardation layer. The retardation layer 116 has a phase delay value between 110 nm and 125 nm. The phase difference layer is satisfied when the z-axis refractive index n _z , which is the thickness direction of the phase difference layer 116 _, is greater than the refractive indexes n _{x and} n _y on the surface of the phase difference layer 116. 116 may have a phase delay value between 110 nm and 125 nm.

Table 1 shows the refractive indices (n _x, n _y , n _z ) of the x-, y- and z-axes of the retardation layer 116 according to Case 1 and Case 2.

n _x n _y n _z Example 1 1.5806 1.5783 1.5841 Example 2 1.5823 1.5795 1.5837

As shown in Table 1, in Example 1, the x-axis refractive index n _x of the retardation layer 116 is 1.5806, the y-axis refractive index n _y is 1.5783, and the z-axis refractive index n _z is 1.5841. In addition, in Example 2, the x-axis refractive index n _x of the retardation layer 116 is 1.5823, the y-axis refractive index n _y is 1.5795, and the z-axis refractive index n _z is 1.5837. As in the first and second embodiments of the present invention, when the z-axis refractive index n _{z of} the retardation layer 116 is larger than the x-axis and y-axis refractive indexes (n _x , n _y ), the retardation layer 116 ) May have a phase delay value between 110 nm and 125 nm.

When the retardation layer 116 has a phase delay value between 110 nm and 125 nm, the luminance of light passing through the retardation layer 116 increases, and the x and y color coordinate values of the light also increase. Therefore, the overall luminance and x and y color coordinate values of the light output from the reflective polarizing member 101 may be increased.

For example, the base layer 111 may have a thickness of about 188 μm, and each of the first, second, and third liquid crystal layers 112a, 112b, and 112c may have a thickness of about 4 μm. Each of the first, second and third adhesives 113, 114, and 115 has a thickness of about 1 μm. In addition, the retardation layer 116 has a thickness of approximately 50 μm, and the fourth adhesive layer 117 has a thickness of approximately 20 μm. Thus, the liquid crystal film 110 has a thickness of approximately 273㎛.

Although not shown in the drawings, the liquid crystal film 110 may further include a dummy liquid crystal layer. When only one of the first, second, and third liquid crystal layers 112a, 112b, and 112c can polarize light of the red, green, and blue wavelength bands, respectively. In this case, the liquid crystal film further includes first, second and third dummy liquid crystal layers (not shown). The first liquid crystal layer 112a and the first dummy liquid crystal layer circularly polarize light of two divided red wavelength bands, and the second liquid crystal layer 112b and the second dummy liquid crystal layer are divided into two green wavelength bands. Are circularly polarized light, and the third liquid crystal layer 112c and the third dummy liquid crystal layer circularly polarize the light of the divided blue wavelength band, respectively.

As such, when the first, second and third dummy liquid crystal layers are further provided on the liquid crystal film 110, the liquid crystal film 110 has a thickness of approximately 288 μm.

4 is a cross-sectional view of a reflective polarizing member according to another exemplary embodiment of the present invention.

Referring to FIG. 4, the reflective polarizing member 102 according to another embodiment of the present invention includes a liquid crystal film 110, a first diffusion layer 120, and a first UV adhesive 130. The first diffusion layer 120 is provided under the liquid crystal film 110 to diffuse light incident on the liquid crystal film 110. The first diffusion layer 120 is attached to the lower surface of the liquid crystal film 110 by the first UV adhesive 130.

In the present invention, the first diffusion layer 120 includes a polycarbonate-based, polysulfone-based, polymethyl methacrylate-based, polystyrene-based, polyvinyl chloride-based, polyvinyl alcohol-based or polynorbornene-based. Accordingly, the first diffusion layer 120 may prevent the liquid crystal film 110 from moving due to heat or moisture.

A diffusion agent for diffusing the light is added to the first diffusion layer 120. In the present invention, the diffusion agent may include a silicon diffusion agent, a magnesium diffusion agent or a calcium oxide diffusion agent. Thus, luminance uniformity of light passing through the first diffusion layer 120 may be improved. In addition, the first diffusion layer 120 further contains a cationic surfactant for preventing the charge of the liquid crystal film 110.

The first UV adhesive 140 is cured by UV to attach the first diffusion layer 120 to the bottom surface of the liquid crystal film 110. In the present invention, the first UV adhesive 140 is an acrylate-based, epoxy acrylate-based, polyester acrylate-based or urethane acrylate-based photopolymerizable monomer and oligomer, acetophenone-based, benzophenone-based or thioxane A ton-based photopolymerizable initiator.

5 is a cross-sectional view of a reflective polarizing member according to another exemplary embodiment of the present invention.

Referring to FIG. 5, the reflective polarizing member 103 according to another embodiment of the present invention includes a liquid crystal film 110, a second diffusion layer 130, and a second UV adhesive 150. The second diffusion layer 130 is provided on the liquid crystal film 110 to diffuse the light emitted from the liquid crystal film 110. The second diffusion layer 130 is attached to the upper surface of the liquid crystal film 110 by the second UV adhesive 150.

In the present invention, the second diffusion layer 130 includes a polycarbonate-based, polysulfone-based, polymethyl methacrylate-based, polystyrene-based, polyvinyl chloride-based, polyvinyl alcohol-based or polynorbornene-based. Accordingly, the second diffusion layer 130 may prevent the liquid crystal film 110 from moving due to heat or moisture.

The second diffusion layer 130 further includes a diffusion agent for diffusing the light and a cationic surfactant for preventing the charge of the liquid crystal film 110.

The second UV adhesive 140 is cured by UV to attach the second diffusion layer 130 to the top surface of the liquid crystal film 110. In the present invention, the second UV adhesive 140 is a photopolymerizable monomer of an acrylate-based, epoxy acrylate-based, polyester acrylate-based or urethane acrylate-based oligomer, acetophenone-based, benzophenone-based or thiol An acidic photopolymerizable initiator is included.

6 is a process chart showing a manufacturing process of the reflective polarizing member shown in Figure 1, Figure 7a is a view showing the state of the UV adhesive before curing, Figure 7b is a view showing the state of the UV adhesive after curing.

Referring to FIG. 6, the first roller 10 moves the completed liquid crystal film 110 in a predetermined direction, and the second and third rollers 21 and 22 move on the moving liquid crystal film 110. It is provided in the lower part, respectively. The second and third rollers 21 and 22 may rotate in a predetermined direction to coat the first and second UV adhesives 140 and 150 on the top and bottom surfaces of the liquid crystal film 110, respectively.

The fourth and fifth rollers 31 and 32 are provided on upper and lower portions of the liquid crystal film 110 coated with the first and second UV adhesives 140 and 150, respectively. The fourth and fifth rollers 31 and 32 rotate in a predetermined direction, respectively, on the lower surface of the first UV adhesive 140 and the upper surface of the second UV adhesive 150. 130).

As shown in FIG. 7A, the first and second UV adhesives 140 and 150 before curing are photocrosslinkable, consisting of a UV initiator (I), a photopolymerizable monomer (M), and a photopolymerizable oligomer (ｏ-ｏ). It consists of a solution of photo-crosslinkable polymers.

The first and second UV irradiators 41 and 42 are provided at upper and lower portions of the liquid crystal film 110 coated with the first and second diffusion layers 120 and 130, respectively. The first and second UV irradiators 41 and 42 irradiate UV light to the liquid crystal film 110 coated with the first and second diffusion layers 120 and 130. The first and second UV adhesives 140 and 150 are cured by the UV light to fix the first and second diffusion layers 120 and 130 to the liquid crystal film 110.                     

As shown in FIG. 7B, when the UV light is irradiated to the first and second UV adhesives 140 and 150, the monomer, the oligomer, and the UV initiator cause the photopolymerization reaction by the UV light. For example, the photopolymerization reaction is a reaction in which the first and second UV adhesives 140 and 150 made of methyl methacrylate (MMA) are irradiated with UV to be converted into poly methyl methacrylate (PMMA). By the photopolymerization reaction, the first and second UV adhesives 140 and 150 are cured, and the first and second diffusion layers 120 and 130 are applied to the first and second UV adhesives 140 and 150. It is attached to the liquid crystal film 110 by.

Through this process, the reflective polarizing member 101 including the first and second diffusion layers 120 and 130 attached to the upper and lower surfaces of the liquid crystal film 110 is completed.

8 is a cross-sectional view of a display device including the reflective polarizing member illustrated in FIG. 1.

Referring to FIG. 8, the display device 401 includes a backlight assembly 200 for generating light, a reflective polarizing member 101 for reflecting and polarizing the light, and a display unit 300 for displaying an image using the light. Include.

The backlight assembly 200 includes a plurality of lamps 210 that generate the light and a diffuser plate 220 provided on the lamp 210 to diffuse the light. The plurality of lamps 210 is formed in a bar shape and arranged in parallel to each other, and the diffusion plate 220 diffuses the light incident from the plurality of lamps 210 to improve brightness uniformity of the light.

The diffusion plate 220 further includes a diffusion sheet 230 for diffusing the light again, and first and second prism sheets 240 and 250 for collecting the diffused light, thereby improving viewing angle and front luminance. In addition, the lower portion of the plurality of lamps 210 is further provided with a reflecting plate 260 for reflecting the light toward the diffusion plate 220 side to improve the light efficiency of the backlight assembly 200.

The display unit 300 is provided above the backlight assembly 200. The display unit 300 is a display panel 310 for displaying an image using the light, a first polarizing plate attached to a lower surface of the display panel 310 to polarize the light provided to the display panel 310 And a second polarizer 330 attached to an upper surface of the display panel 310 to polarize the light emitted from the display panel 310.

The reflective polarizing member 101 is interposed between the display unit 300 and the backlight assembly 200. The reflective polarizing member 101 polarizes the light by transmitting the P wave and reflecting the S wave of the light provided from the backlight assembly 200. The light reflected by the reflective polarization member 101 is reflected back by the backlight assembly 200 and is incident to the reflective polarization member 101 again. This series of processes is repeated so that most of the light emitted from the backlight assembly 200 passes through the reflective polarizing member 101.

In Table 2, luminance points of 13 points and 5 points of the display panel according to Experimental Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3 are presented.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Experimental Example 1 Luminance average (13 points) 1,521 106 130 135 Luminance average (5 points) 1,516 109 134 138 x coordinate 0.3022 0.3136 0.3183 0.3197 y coordinate 0.3048 0.3467 0.3550 0.3679 Luminance uniformity 76.3% 69.7% 73.1% 75.9% Luminance comparison (13 points) 100% 7.0% 8.6% 8.8% Luminance comparison (5 points) 100% 7.2% 8.8% 9.1% Luminance efficiency (13 points) 100% 102.3 Luminance efficiency (5 points) 100% 103.4

In Table 2, Comparative Example 1 shows the result of measuring the light emitted from the backlight assembly, and Comparative Example 2 shows the result of measuring the light emitted from the display panel in the display device without the reflective polarizing member. Indicated. Comparative Example 3 shows a result of measuring light emitted from a display panel in a display device having a 3M Dual Brightness Enhancement Film (DBEF) (not shown). Experimental Example 1 shows the result of measuring the light emitted from the display panel 310 in the display device 401 having the reflective polarizing member 101 of the present invention.

According to Table 2, the luminance was increased in the order of Comparative Example 2, Comparative Example 3, and Experimental Example 1 at 13 points and 5 points, and the x and y coordinates were shown in Comparative Example 2, Comparative Example 3, and Experimental Example 1 In order. The luminance uniformity was increased in the order of Comparative Example 2, Comparative Example 3 and Experimental Example 1 at both 13 points and 5 points.

 When the luminance of the light measured in Comparative Example 1 was 100%, the luminance of the light measured in Comparative Examples 2, 3, and 1 was 7.0%, 8.6%, and 8.8%, respectively (at 13 sites). When the luminance of the light measured in Comparative Example 1 was 100%, the luminance of the light measured in Comparative Examples 2, 3, and 1 was 7.2%, 8.8%, and 9.1%, respectively (at 5 points).                     

When the luminance efficiency of Comparative Example 3 was 100%, the luminance efficiency of Experimental Example 1 recorded 103.3% and 102.5%, which were increased by about 3.3% and about 2.5%, respectively, from 13 and 5 points. As a result, when adopting the reflective polarizing member 101 according to an embodiment of the present invention, the brightness, x, y coordinates and luminance uniformity of the display device 401 are improved, and thus the display quality of the display device 401 is improved. Can be improved.

9 is a cross-sectional view of a reflective polarizing member according to still another exemplary embodiment of the present invention, and FIG. 10 is a cross-sectional view of the organic particles illustrated in FIG. 9.

Referring to FIG. 9, the reflective polarizing member 501 according to another embodiment of the present invention may include a diffuse reflection film 510, a first diffusion layer 520, a second diffusion layer 530, and a first UV adhesive 540. And a second UV adhesive 550.

The diffuse reflection film 510 is formed of a plurality of organic particles 512 contained in the polymer resin 511 and stretched in a predetermined direction with the polymer resin 511 to be incident by the plurality of organic particles 512. It selectively diffusely reflects light.

In one embodiment of the present invention, the polymer resin 511 is a polycarbonate, polyethylene terephthalate, polyimide, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol or Polynorbornene-based.

As shown in FIG. 10, the organic particles 512 consist of methacrylate butadiene styrene and have a core shell structure. Here, the core portion 512a of the organic particles 512 is a portion in which butadiene and styrene are cross-linked, and the shell portion 512b_ of the organic particles 512 has a portion surrounded by polymethylmethacrylate around the core portion. Although not shown in the drawing, the butadiene and the styrene are connected to each other in a mesh structure in the core part 512a.

The diffuse reflection film 510 selectively diffuses the incident light by a difference in refractive index between the stretched direction and the non-stretched direction of the organic particles 512. Specifically, the P wave passes through the diffuse reflection film 510 and the S wave is reflected by the stretched organic particles 512. Here, the S wave reflected by the diffuse reflection film 510 is diffused by the organic particles 512. The reflected S-waves are reflected back to the diffuse reflection film 510, and a series of processes are repeated so that most of the light provided to the diffuse reflection film 510 passes through the diffuse reflection film 510.

The first and second diffusion layers 520 and 530 are provided at upper and lower portions of the diffuse reflection film 510 to diffuse the light. In the present invention, the first and second diffusion layers 520 and 530 are made of polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol or polynorbornene. Can be. Thus, the first and second diffusion layers 520 and 530 may prevent the diffusion of the diffuse reflection film 510.

The first and second diffusion layers 520 and 530 further include a diffusion agent for diffusing the light and a cationic surfactant for preventing the charge of the diffusion reflection film 510.

The first and second UV adhesives 540 and 550 are cured by ultraviolet rays to attach the first and second diffusion layers 520 and 530 to the bottom and top surfaces of the diffuse reflection film 510, respectively. In the present invention, the first and second UV adhesives 540 and 550 are photopolymerizable monomers of acrylate-based, epoxy acrylate-based, polyester acrylate-based or urethane acrylate-based oligomers, acetophenone-based and benzophene. Non- or thioxanthone type photopolymerization initiator is included.

Although not shown in the drawing, the reflective polarizing member 500 may include a diffusion layer on only one of a lower surface and an upper surface of the diffuse reflection film 510.

FIG. 11 is a process diagram illustrating a manufacturing process of the reflective polarizing member illustrated in FIG. 9. The same reference numerals are given to the same components as those shown in FIG. 6 among the components shown in FIG. 11.

Referring to FIG. 11, the first roller 10 moves the completed diffuse reflection film 510 in a predetermined direction, and the second and third rollers 21 and 22 move the diffuse reflection film 510. It is provided at the upper and lower portions of each. The second and third rollers 21 and 22 are coated in the first and second UV adhesives 540 and 550 on the top and bottom surfaces of the diffuse reflection film 510 while rotating in a predetermined direction.

The fourth and fifth rollers 31 and 32 are provided on upper and lower portions of the diffuse reflection film 510 coated with the first and second UV adhesives 540 and 550, respectively. The fourth and fifth rollers 31 and 32 rotate in a predetermined direction, respectively, on the lower surfaces of the first UV adhesives 540 and 550 and the upper surfaces of the second UV adhesives 520 and 530, respectively. )).

First and second UV irradiators 41 and 42 may be provided on upper and lower portions of the diffuse reflection film 510 coated with the first and second diffusion layers 520 and 530, respectively. The first and second UV irradiators 41 and 42 irradiate UV light to the diffuse reflection film 510 coated with the first and second diffusion layers 520 and 530. The first and second UV adhesives 540 and 550 are cured by the UV light to fix the first and second diffusion layers 520 and 530 to the diffuse reflection film 510.

Through this process, the reflective polarizing member 501 having the first and second diffusion layers 520 and 530 attached to the upper and lower surfaces of the diffuse reflection film 510 is completed.

FIG. 12 is a cross-sectional view of a display device including the reflective polarizing member illustrated in FIG. 9. Of the components shown in FIG. 12, the same reference numerals are given to the same components as those shown in FIG. 8, and detailed description thereof will be omitted.

Referring to FIG. 12, the display device 402 includes a backlight assembly 200 for generating light, a reflective polarizing member 501 for reflecting and polarizing the light, and a display unit 300 for displaying an image using the light. Include.

The reflective polarizer 501 is interposed between the display unit 300 and the backlight assembly 200. The reflective polarizing member 501 polarizes the light by transmitting the P wave and diffusing the S wave of the light provided from the backlight assembly 200. The light diffused and reflected by the reflective polarizing member 501 is reflected back by the backlight assembly 200 and is incident to the reflective polarizing member 501. This series of processes is repeated so that most of the light emitted from the backlight assembly 200 passes through the reflective polarizing member 501.

According to such a reflective polarizing member, a display device having the same, and a manufacturing method thereof, the reflective polarizing member has a function of diffusing light and a diffusion layer for preventing the liquid crystal film from rising.

Therefore, it is possible to prevent the phenomenon of the reflective polarizing member and to improve the overall brightness and the uniformity of brightness of the display device. As a result, the display quality of the display device can be improved.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

Claims (40)

A liquid crystal film made of a liquid crystal twisted in a predetermined direction to reflect light parallel to the twisting direction of the liquid crystal and to transmit the remaining light; And And a diffusion layer attached to the liquid crystal film to diffuse the light. The method of claim 1, wherein the diffusion layer, A first diffusion layer attached to a lower surface of the liquid crystal film to diffuse the light provided to the liquid crystal film; And And a second diffusion layer attached to an upper surface of the liquid crystal film to diffuse the light emitted from the liquid crystal film. The reflective polarization of claim 1, wherein the diffusion layer comprises a polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene. absence. The reflective polarizing member of claim 1, further comprising a diffusion agent added to the diffusion layer to diffuse the light. The reflective polarizing member of claim 4, wherein the diffusion agent comprises a silicon diffusion agent, a magnesium diffusion agent, or a calcium oxide diffusion agent. The reflective polarizing member of claim 1, further comprising a cationic-based surfactant contained in the diffusion layer to prevent charging of the liquid crystal film. The reflective polarizing member of claim 1, further comprising an adhesive made of a UV curable material to attach the diffusion layer to the liquid crystal film. The method of claim 7, wherein the adhesive is an acrylate-based, epoxy acrylate-based, polyester acrylate-based or urethane acrylate-based photopolymerizable monomers and oligomers, acetophenone-based, benzophenone-based or thioxanthone-based photopolymerizable Reflective polarizing member comprising an initiator. According to claim 1, wherein the liquid crystal film, Base layer; A liquid crystal layer provided on the base layer and composed of cholesteric liquid crystal to circularly polarize the light; And And a retardation layer provided on the liquid crystal layer to linearly polarize the circularly polarized light. The method of claim 9, wherein the liquid crystal layer, A first liquid crystal layer for circularly polarizing light of a red wavelength band; A second liquid crystal layer for circularly polarizing light in the green wavelength band; And And a third liquid crystal layer for circularly polarizing light in the blue wavelength range. The reflective polarization member of claim 10, wherein the first, second and third liquid crystal layers are sequentially stacked on the base layer. The method of claim 11, wherein the liquid crystal film, A first adhesive for attaching the first liquid crystal layer on the base layer; A second adhesive for attaching the second liquid crystal layer on the first liquid crystal layer; And And a third adhesive for attaching the third liquid crystal layer on the second liquid crystal layer. The reflective polarizing member of claim 10, wherein the cholesteric liquid crystal and the vertical alignment (VA) liquid crystal are mixed in a ratio of 8: 2 in the first liquid crystal layer. The reflective polarizing member of claim 10, wherein the cholesteric liquid crystal and the VA liquid crystal are mixed in a ratio of 7: 3 in the second liquid crystal layer. The reflective polarizer of claim 10, wherein the cholesteric liquid crystal and the VA liquid crystal are mixed in a ratio of 6: 4 in the third liquid crystal layer. The reflective polarizing member of claim 9, wherein the base layer is made of polyethylene terephthalate. The retardation layer of claim 9, wherein the retardation layer is a λ / 4 retardation layer. And the z-axis refractive index in the thickness direction of the retardation layer is larger than that of the x-axis and y-axis on the surface of the λ / 4 retardation layer. 18. The reflective polarizing member of claim 17, wherein the retardation value of the retardation layer is 110 nm to 125 nm. The reflective polarizing member of claim 1, wherein the diffusion layer is attached to a lower surface of the liquid crystal film to diffuse the light provided to the liquid crystal film. The reflective polarizing member of claim 1, wherein the diffusion layer is attached to an upper surface of the liquid crystal film to diffuse the light emitted from the liquid crystal film. A diffuse reflection film composed of a plurality of organic particles stretched in a predetermined direction with a polymer resin and contained in the polymer resin to selectively diffusely reflect light incident by the organic particles; And And a diffusion layer attached to the diffusion reflection film to diffuse the light. The method of claim 21, wherein the diffusion layer, A first diffusion layer attached to a bottom surface of the diffusion reflection film to diffuse the light provided to the diffusion reflection film; And And a second diffusion layer attached to an upper surface of the diffusion reflection film to diffuse the light emitted from the diffusion reflection film. The method of claim 21, wherein the diffusion layer is a polycarbonate, polyethylene terephthalate, polyimide, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol or polynorbornene Reflective polarizing member comprising a. 25. The reflective polarizing member of claim 23, further comprising a diffusing agent added to the diffusing layer to diffuse the light. 25. The reflective polarizing member of claim 24, wherein the diffusing agent comprises a silicon diffuser, a magnesium diffuser, or a calcium oxide diffuser. 22. The reflective polarizing member of claim 21, further comprising a cation-based surfactant contained in the diffusion layer to prevent charging of the diffuse reflection film. 22. The reflective polarizing member of claim 21, further comprising an adhesive made of a UV curable material to adhere the diffusion layer to the diffusion reflection film. 28. The method of claim 27, wherein the adhesive is an acrylate-based, epoxy acrylate-based, polyester acrylate-based or urethane acrylate-based photopolymerizable monomer and oligomer, acetophenone-based, benzophenone-based or thioxanthone-based photopolymerizable Reflective polarizing member comprising an initiator. The method of claim 21, wherein the polymer resin is polycarbonate, polyethylene terephthalate, polyimide, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol or polynorbo Reflective polarizing member comprising a linen system. 22. The reflective polarizing member of claim 21, wherein the organic particles have a core shell structure composed of methacrylate butadiene styrene. 31. The method of claim 30, wherein the core portion of the organic particles is a cross-linked butadiene and styrene, And the shell portion of the organic particles is a portion surrounding the core portion with polymethyl methacrylate. A backlight assembly for generating light; A reflective polarization member disposed on the backlight assembly and configured to selectively reflect and polarize the light; And A display panel provided on the reflective polarizing member and displaying an image using the polarized light; The reflective polarizing member, A liquid crystal film made of a liquid crystal twisted in a predetermined direction to reflect light parallel to the twisting direction of the liquid crystal and to transmit the remaining light; And And a diffusion layer attached to the liquid crystal film to diffuse the light. A backlight assembly for generating light; A reflective polarization member disposed on the backlight assembly and configured to selectively reflect and polarize the light; And A display panel provided on the reflective polarizing member and displaying an image using the polarized light; The reflective polarizing member, A diffuse reflection film composed of a plurality of organic particles stretched in a predetermined direction with the polymer resin and contained in the polymer resin to selectively diffusely reflect the light incident by the organic particles; And And a diffusion layer attached to the diffusion reflection film to diffuse the light. Forming a liquid crystal film made of a liquid crystal twisted in a predetermined direction to reflect light parallel to the twist direction of the liquid crystal and to transmit the remaining light; And And attaching a diffusion layer for diffusing the light onto the liquid crystal film. The method of claim 34, wherein forming the liquid crystal film, Forming a liquid crystal layer formed of cholesteric liquid crystal on the base layer to circularly polarize the light; Curing the liquid crystal layer; And Forming a phase difference layer for linearly polarizing the circularly polarized light on the cured liquid crystal layer; 36. The method of claim 35, wherein the liquid crystal layer is formed of a mixture of cholesteric liquid crystal and VA liquid crystal in a predetermined ratio in a solvent and a UV initiator added thereto. 37. The method of claim 36, wherein in the curing of the liquid crystal layer, the liquid crystal layer is cured by irradiating UV to the liquid crystal layer containing the UV initiator. The method of claim 34, wherein attaching the diffusion layer comprises: Coating a UV adhesive on the liquid crystal film; Coating the diffusion layer on the liquid crystal film coated with the UV adhesive; And And hardening the UV adhesive to fix the diffusion layer to the liquid crystal film. Stretching the polymer resin containing a plurality of organic particles in a predetermined direction to form a diffuse reflection film having organic particles having a core shell structure; And And attaching a diffusion layer to diffuse the light onto the diffuse reflection film. The method of claim 39, wherein attaching the diffusion layer comprises: Coating a UV adhesive on the diffuse reflection film; Coating the diffusion layer on the diffusion reflecting film coated with the UV adhesive; And Curing the UV adhesive to attach the diffusion layer to the diffuse reflection film.

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