JP2006106653A - Reflecting polarizing material, display using the same, and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflecting polarizing material having an optical diffusion function, a display that uses it, and its manufacturing method. <P>SOLUTION: This reflecting polarizing material includes a liquid crystal film and a diffusion layer. The liquid crystal film is made by using liquid crystals that are twisted in a predetermined direction and reflects the light parallel to the twist direction of the liquid crystals but passes the remaining light. The diffusion layer is attached to the liquid crystal film and diffuses the light. Thus, wrinkles of the reflective polarizer material are prevented, and the uniformity of luminance is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  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 diffusion function, a display device having the same, and a manufacturing method thereof.

  It is one of flat panel display devices that display images using liquid crystal (Liquid Crystal), and is thinner and lighter than other display devices, and has the advantages of having a low driving voltage and low power consumption. Widely used throughout the industry.

  In such a liquid crystal display device, a liquid crystal display panel for displaying an image is a non-light-emitting element that does not emit light by itself, and thus requires a light source device for providing another light.

  The light source device is a light source that generates light, and includes a thin and long cylindrical cold cathode fluorescent lamp (CCFL). The light source device is classified into an edge type and a direct type according to the position of the light source.

  One or two light sources are provided on the side surface of the transparent light guide plate in the edge type, and light generated from the light sources is reflected multiple times through one surface of the light guide plate and emitted to the liquid crystal display panel. On the other hand, a large number of light sources in the direct type are provided directly below the liquid crystal display panel, a diffusion plate is provided on the entire surface of the light source, and a reflecting plate is provided on the back surface of the light source. Therefore, the light emitted from the light source is reflected by the reflection 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% 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. When 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 69.7%, which is smaller than the light emitted from the light source device. The display quality of the liquid crystal display device deteriorates due to such a decrease in luminance and luminance uniformity.

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

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

  Another object of the present invention is to provide a method applied to manufacture the above-described reflective polarizing member.

  A reflective polarizing member according to one aspect of the present invention includes a liquid crystal film and a diffusion layer. The liquid crystal film is composed of liquid crystal twisted in a predetermined direction, reflects light parallel to the twist direction of the liquid crystal, and transmits the remaining light. The diffusion layer is attached to the liquid crystal film and diffuses the light.

  A reflective polarizing member according to another aspect of the present invention includes a diffuse reflection film and a diffusion layer. The diffuse reflection film is made of a polymer resin and a large number of organic particles stretched in a predetermined direction and contained in the polymer resin, and selectively diffuses and reflects light incident on the organic particles. The diffusion layer is attached to the diffuse reflection film and diffuses the light.

  According to still another aspect of the present invention, a display device includes a backlight assembly that generates light, a reflective polarizing member that is provided on an upper portion of the backlight assembly and selectively reflects and polarizes the light, and the reflective polarizing member. And a display panel for displaying an image using the polarized light.

  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, reflects light parallel to the twist direction of the liquid crystal, and transmits the remaining light. The diffusion layer is attached to the liquid crystal film and diffuses the light.

  According to still another aspect of the present invention, a display device includes a backlight assembly that generates light, a reflective polarizing member that is provided on the backlight assembly and selectively reflects and polarizes the light, and the reflective polarizing member. A display panel provided on the display panel for displaying an image using the polarized light;

  The reflective polarizing member includes a diffuse reflection film and a diffusion layer. The diffuse reflection film is made of a polymer resin and a large number of organic particles stretched in a predetermined direction and contained in the polymer resin, and selectively diffuses and reflects light incident on the organic particles. The diffusion layer is attached to the diffuse reflection film and diffuses the light.

  In a method for manufacturing a reflective polarizing member according to still another aspect of the present invention, there is provided a liquid crystal film that is composed of liquid crystal twisted in a predetermined direction, reflects light parallel to the twist direction of the liquid crystal, and transmits the remaining light. A diffusion layer for forming and diffusing the light is attached to the liquid crystal film.

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

  According to such a reflective polarizing member, a display device having the same, and a manufacturing method thereof, the diffusion layer is added to the reflective polarizing member, thereby preventing the phenomenon of wrinkling of the reflective polarizing member, As a result, the display quality of the display device can be improved.

  Hereinafter, preferred 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 specifically illustrating the liquid crystal film illustrated in FIG. 1, and FIG. 3 is a liquid crystal illustrated in FIG. It is a figure which shows a layer concretely.

  As shown in FIG. 1, a reflective polarizing member 101 according to an embodiment of the present invention includes a liquid crystal film 110, a first diffusion layer 120, a second diffusion layer 130, a first ultraviolet (UV) adhesive 140, and a second UV adhesive. Agent 150 is included.

  The first diffusion layer 120 is provided below the liquid crystal film 110 and diffuses 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 140. The second diffusion layer 130 is provided on the liquid crystal film 110 and diffuses 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 to 300 μm. 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 formed of a material having a low coefficient of thermal expansion and a low moisture 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 may be formed of polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene. Accordingly, the first and second diffusion layers 120 and 130 can prevent a phenomenon that the liquid crystal film 110 is wrinkled by heat or moisture.

  A diffusing agent for diffusing light is added to the first and second diffusion layers 120 and 130. In the present invention, the diffusing agent can include a silicon diffusing agent, a magnesium diffusing agent, or a calcium oxide diffusing agent. Accordingly, it is possible to improve the luminance uniformity of the light that has passed through the first and second diffusion layers 120 and 130. Further, the first and second diffusion layers 120 and 130 further include a positive ion series 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 and attach the first and second diffusion layers 120 and 130 to the lower surface and the upper surface of the liquid crystal film 110, respectively. In the present invention, the first and second UV adhesives 140 and 150 are acrylate, epoxy acrylate, polyester acrylate, or urethane acrylate photopolymerizable monomers, acrylate, epoxy acrylate, polyester acrylate, or urethane. An acrylate-based oligomer and an acetophenone-based, benzophenone-based, or thioxanthone-based photopolymerizable initiator are included. The first and second UV adhesives 140 and 150 will be described more specifically with reference to FIGS. 7 and 8.

  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 composed of a polyethylene terephthalate system.

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

  The liquid crystal layer 112 includes a first liquid crystal layer 112a that circularly polarizes light in the red wavelength band, a second liquid crystal layer 112b that circularly polarizes light in the green wavelength band, and a third liquid crystal layer 112c that circularly polarizes light in the blue wavelength band. including. 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 attached to the upper surface of the first liquid crystal layer 112a by the second adhesive 114. The third liquid crystal layer 112c is attached to the upper surface of the second liquid crystal layer 112b by the third adhesive 115.

  On the other hand, the first, second, and third liquid crystal layers 112a, 112b, and 112c have UV light in a state where a cholesteric liquid crystal and a vertical alignment (VA) liquid crystal are mixed in a predetermined ratio as a solvent. Consists of a mixed material containing an initiator. Here, in order to selectively reflect light in different wavelength bands, the ratio of the cholesteric liquid crystal and the VA liquid crystal mixed in the first, second, and third liquid crystal layers 112a, 112b, and 112c is changed. Specifically, cholesteric liquid crystal and VA liquid crystal are mixed in a ratio of 8: 2 in the first liquid crystal layer 112a, and cholesteric liquid crystal and VA liquid crystal are mixed in a ratio of 7: 3 in the second liquid crystal layer 112b. Cholesteric liquid crystal and VA liquid crystal are mixed in the third liquid crystal layer 112c at a ratio of 6: 4.

  As shown in FIG. 3, the cholesteric liquid crystal 112-1 has one stage of a liquid crystal phase (Phase) and has a form in which rod-type liquid crystal molecules are spirally twisted. The cholesteric liquid crystal 112-1 repeats the twist at a constant interval, and the repeated length is called a 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 values obtained by multiplying the respective pitch (P) and the refractive index of the cholesteric liquid crystal 112-1. Accordingly, 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 reflect light polarized in the same direction as the twist direction of the cholesteric liquid crystal 112-1, and pass light in other wavelength bands as they are. Accordingly, the light reflected by the first, second, and third liquid crystal layers 112a, 112b, and 112c has a state of right circular polarization or left circular polarization depending on the twist direction of the cholesteric liquid crystal 112-1, and is reflected. The transmitted light has a circular polarization state opposite to the reflected light.

  Thereafter, the light reflected by the first, second, and third liquid crystal layers 112a, 112b, and 112c further enters the first, second, and third liquid crystal layers 112a, 112b, and 112c. Such a series of processes is repeated. Eventually, most of the light has one circular polarization state and passes through the first, second, and third liquid crystal layers 112a, 112b, and 112c.

  A 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 a fourth adhesive 117. The retardation layer 116 linearly polarizes the light circularly polarized by the liquid crystal layer 112. Therefore, the light that has passed through the retardation layer 116 has a P-wave component.

As an example 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 z-axis refractive index ( _nz ), which is the thickness direction of the retardation layer 116, satisfies the condition that the x-axis and y-axis refractive indexes ( _nx , _ny ) on the surface of the retardation layer 116 are larger. In some cases, the retardation layer 116 may have a phase delay value between 110 nm and 125 nm.

Table 1 shows the refractive indexes ( _nx , _ny , _nz ) of the x-axis, y-axis, and z-axis of the retardation layer 116 according to the first case and the second case.

表１に示すように、実施例１において、位相差層１１６のｘ軸屈折率（ｎ_x）は１.５８０６であり、ｙ軸屈折率（ｎ_y）は１.５７８３であり、ｚ軸屈折率（ｎ_z）は１.５８４１である。また、実施例２において、位相差層１１６のｘ軸屈折率（ｎ_x）は１.５８２３であり、ｙ軸屈折率（ｎ_y）は１.５７９５であり、ｚ軸屈折率（ｎ_z）は１.５８３７である。本発明の実施例１及び実施例２のように、位相差層１１６のｚ軸屈折率（ｎ_z）がｘ軸とｙ軸屈折率（ｎ_x、ｎ_y）より大きい時、位相差層１１６は、１１０ｎｍ〜１２５ｎｍ間の位相遅延値を有する構成とすることができる。

As shown in Table 1, in Example 1, x-axis refractive index of the phase difference layer 116 (n _x) is 1.5806, y-axis refractive index (n _y) is 1.5783, z-axis refractive The rate (n _z ) is 1.5841. Further, in Example 2, x-axis refractive index of the phase difference layer 116 (n _x) is 1.5823, y-axis refractive index (n _y) is 1.5795, z-axis refractive index (n _z) Is 1.5837. When the z-axis refractive index ( _nz ) of the retardation layer 116 is larger than the x-axis and y-axis refractive indexes ( _nx , _ny ) as in the first and second embodiments of the present invention, the retardation layer 116 is used. Can 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 the light that has passed through the retardation layer 116 increases, and the x and y color coordinate values of the light also increase. Accordingly, it is possible to increase the overall luminance and the x and y color coordinate values of the light output from the reflective polarizing member 101.

  As an example of the present invention, the base layer 111 has a thickness of approximately 188 μm, and the first, second, and third liquid crystal layers 112a, 112b, and 112c each have a thickness of approximately 4 μm. The first, second and third adhesives 113, 114 and 115 each have a thickness of approximately 1 μm. The retardation layer 116 has a thickness of approximately 50 μm, and the fourth adhesive layer 117 has a thickness of approximately 20 μm. Accordingly, the liquid crystal film 110 has a thickness of approximately 273 μm.

  Although not shown, the liquid crystal film 110 may further include a dummy liquid crystal layer. In some cases, only the first, second, and third liquid crystal layers 112a, 112b, and 112c cannot polarize light in the red, green, and blue wavelength bands. 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 respectively circularly polarize the light in the red wavelength band divided into two, and the second liquid crystal layer 112b and the second dummy liquid crystal layer in the light of the green wavelength band divided into two. Are circularly polarized, and the third liquid crystal layer 112c and the third dummy liquid crystal layer circularly polarize the light in the blue wavelength band divided into two.

  Thus, when the liquid crystal film 110 further includes the first, second, and third dummy liquid crystal layers, the liquid crystal film 110 has a thickness of approximately 288 μm.

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

  As shown in 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 below the liquid crystal film 110 and diffuses light incident on the liquid crystal film 110. The first diffusion layer 120 is provided on the lower surface of the liquid crystal film 110 by the first UV adhesive 130.

  The first diffusion layer 120 in the present invention includes polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene. Therefore, the first diffusion layer 120 can prevent a phenomenon that the liquid crystal film 110 is wrinkled by heat or moisture.

  A diffusion agent for diffusing light is added to the first diffusion layer 120. In the present invention, the diffusing agent can include a silicon diffusing agent, a magnesium diffusing agent, or a calcium oxide diffusing agent. Accordingly, it is possible to improve the luminance uniformity of the light that has passed through the first diffusion layer 120. Further, the first diffusion layer 120 further includes a positive ion series surfactant for preventing the liquid crystal film 110 from being charged.

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

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

  As shown in 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 and diffuses 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 polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene. Therefore, the second diffusion layer 130 can prevent a phenomenon that the liquid crystal film 110 is wrinkled by heat or moisture.

  The second diffusion layer 130 further includes a diffusing agent for diffusing light and a positive ion series surfactant for preventing the liquid crystal film 110 from being charged.

  The second UV adhesive 140 is cured by UV and attaches the second diffusion layer 130 to the upper surface of the liquid crystal film 110. In the present invention, the second UV adhesive 140 is an acrylate, epoxy acrylate, polyester acrylate, or urethane acrylate photopolymerizable monomer, acrylate, epoxy acrylate, polyester acrylate, or urethane acrylate oligomer, And an acetophenone-based, benzophenone-based, or thioxanthone-based photopolymerizable initiator.

  6 is a process diagram illustrating a manufacturing process of the reflective polarizing member illustrated in FIG. 1, FIG. 7 is a diagram illustrating a state of the UV adhesive before being cured, and FIG. 8 is a UV adhesive after being cured. It is a figure which shows the state of.

  As shown in 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 are provided above and below the moving liquid crystal film 110, respectively. It is done. The second and third rollers 21 and 22 coat the upper and lower surfaces of the liquid crystal film 110 with the first and second UV adhesives 140 and 150, respectively, while rotating in a predetermined direction.

  The fourth and fifth rollers 31 and 32 are respectively provided above / below the liquid crystal film 110 coated with the first and second UV adhesives 140 and 150. The fourth and fifth rollers 31 and 32 coat the first and second diffusion layers 120 and 130 on the lower surface of the first UV adhesive 140 and the upper surface of the second UV adhesive 150, respectively, while rotating in a predetermined direction.

  As shown in FIG. 7, before being cured, the first and second UV adhesives 140 and 150 are composed of a UV initiator (I), a photopolymerizable monomer (M), and a photopolymerizable oligomer (o-o). It is formed from a photo-crosslinkable polymer solution.

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

  As shown in FIG. 8, when UV light is applied to the first and second UV adhesives 140 and 150, the monomer, oligomer, and UV initiator cause a 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 changed to polymethyl methacrylate (PMMA). The first and second UV adhesives 140 and 150 are cured by such a photopolymerization reaction, and the first and second diffusion layers 120 and 130 are attached to the liquid crystal film 110 by the first and second UV adhesives 140 and 150. It is done.

  Through such a 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.

  FIG. 9 is a cross-sectional view showing a display device employing the reflective polarizing member shown in FIG.

  As shown in FIG. 9, the display device 401 includes a backlight assembly 200 that generates light, a reflective polarizing member 101 that reflects and polarizes light, and a display unit 300 that displays an image using light.

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

  A diffusion sheet 230 for further diffusing light and first and second prism sheets 240 and 250 for condensing the diffused light are further provided on the diffusion plate 220 to improve the viewing angle and front luminance. . In addition, a reflector 260 that reflects light toward the diffuser 220 is further provided below the many lamps 210, so that the light efficiency of the backlight assembly 200 can be improved.

  The display unit 300 is provided on the upper part of the backlight assembly 200. The display unit 300 includes a display panel 310 that displays an image using light, a first polarizing plate 320 that is attached to a lower surface of the display panel 310 and polarizes light provided to the display panel 310, and an upper surface of the display panel 310. And a second polarizing plate 330 that polarizes 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. Of the light provided from the backlight assembly 200, the reflective polarizing member 101 transmits the P wave and reflects the S wave to polarize the light. The light reflected by the reflective polarizing member 101 is reflected again by the backlight assembly 200 and further enters the reflective polarizing member 101. Such a series of processes is repeated, and most of the light emitted from the backlight assembly 200 passes through the reflective polarizing member 101.

  Table 2 presents the average luminance values of 13 points and 5 points of the display panels according to Experimental Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3.

表２において、比較例１はバックライトアセンブリから出射した光を測定した結果値を示し、比較例２は反射偏光部材を備えない表示装置で表示パネルから出射した光を測定した結果値を示す。比較例３は、３Ｍ社の輝度強化フィルム（Ｄｕａｌ Ｂｒｉｇｈｔｎｅｓｓ Ｅｎｈａｎｃｅｍｅｎｔ Ｆｉｌｍ；ＤＢＥＦ）（図示せず）を備えた表示装置で表示パネルから出射した光を測定した結果値を示す。実験例１は、本発明の反射偏光部材１０１を備えた表示装置４０１で表示パネル３１０から出射した光を測定した結果値を示す。

In Table 2, Comparative Example 1 shows a result value obtained by measuring light emitted from the backlight assembly, and Comparative Example 2 shows a result value obtained by measuring light emitted from the display panel by a display device that does not include a reflective polarizing member. The comparative example 3 shows the result value which measured the light radiate | emitted from the display panel with the display apparatus provided with the brightness | luminance enhancement film (Dual Brightness Enhancement Film; DBEF) (not shown) of 3M company. Experimental Example 1 shows a result value obtained by measuring light emitted from the display panel 310 by the display device 401 including the reflective polarizing member 101 of the present invention.

  According to Table 2, the luminance increases in the order of Comparative Example 2, Comparative Example 3 and Experimental Example 1 at 13 points and 5 points, and the x coordinate and y coordinate increase in the order of Comparative Example 2, Comparative Example 3 and Experimental Example 1. It was. The luminance uniformity increased in the order of Comparative Example 2, Comparative Example 3, and Experimental Example 1 at 13 points and 5 points.

  When the luminance of light measured in Comparative Example 1 is regarded as 100%, the luminance of light measured in Comparative Example 2, Comparative Example 3 and Experimental Example 1 is 7.0%, 8.6% and 8%, respectively. 0.8% (13 points). When the luminance of light measured in Comparative Example 1 is regarded as 100%, the luminances of light measured in Comparative Example 2, Comparative Example 3 and Experimental Example 1 are 7.2%, 8.8% and 9 respectively. 0.1% (5 points).

  When the luminance efficiency of Comparative Example 3 is assumed to be 100%, the luminance efficiency of Experimental Example 1 is 13 points and 5 points, 103.3%, which are about 3.3% and about 2.5% higher than Comparative Example 3, respectively. 102.5% was recorded. As a result, when the reflective polarizing member 101 according to an example of the present invention is employed, the luminance, x, y coordinates, luminance uniformity, and the like of the display device 401 are improved, and the display quality of the display device 401 can be improved. .

  FIG. 10 is a cross-sectional view of a reflective polarizing member according to still another embodiment of the present invention, and FIG. 11 is a cross-sectional view of the organic particles illustrated in FIG.

  As shown in FIG. 10, the reflective polarizing member 501 according to another embodiment of the present invention includes a diffuse reflection film 510, a first diffusion layer 520, a second diffusion layer 530, a first UV adhesive 540, and a second UV adhesive 550. including.

  The diffuse reflection film 510 is composed of a large number of organic particles 512 that are stretched in a predetermined direction with the polymer resin 511 and are included in the polymer resin 511, and selectively diffuses light incident on the large number of organic particles 512. Reflect.

  As an example of the present invention, the polymer resin 511 includes polycarbonate, polyethylene terephthalate, polyimide, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene.

  As shown in FIG. 11, the organic particles 512 are made of methacrylate butadiene styrene and have a core shell structure. Here, the core portion 512a of the organic particle 512 is a portion in which butadiene and styrene are cross-linked, and the shell portion 512b of the organic particle 512 is a portion in which the periphery of the core portion is surrounded by polymethyl methacrylate. Although not shown, butadiene and styrene are connected to each other in a network structure at the core portion 512a.

  The diffuse reflection film 510 selectively diffuses and reflects incident light due to a difference in refractive index between the direction in which the organic particles 512 are stretched and the direction in which the organic particles 512 are not stretched. 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 wave is reflected again by the diffuse reflection film 510, and such a series of processes is repeated, and 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 respectively provided above / below the diffuse reflection film 510 to diffuse light. In the present invention, the first and second diffusion layers 520 and 530 may be composed of polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene. Therefore, the first and second diffusion layers 520 and 530 can prevent a phenomenon that the diffuse reflection film 510 is wrinkled.

  The first and second diffusion layers 520 and 530 further include a diffusing agent for diffusing light and a positive ion series surfactant for preventing the diffusion reflection film 510 from being charged.

  The first and second UV adhesives 540 and 550 are cured by ultraviolet rays and attach the first and second diffusion layers 520 and 530 to the lower surface and the upper surface of the diffuse reflection film 510, respectively. In the present invention, the first and second UV adhesives 540 and 550 are acrylate-based, epoxy acrylate-based, polyester acrylate-based, or urethane acrylate-based photopolymerizable monomers, acrylate-based, epoxy acrylate-based, polyester acrylate-based, or urethane. An acrylate-based oligomer and an acetophenone-based, benzophenone-based, or thioxanthone-based photopolymerizable initiator are included.

  Although not shown, the reflective polarizing member 500 can be provided with a diffusion layer on only one of the lower surface and the upper surface of the diffuse reflection film 510.

  FIG. 12 is a process diagram illustrating a manufacturing process of the reflective polarizing member illustrated in FIG. 10. Of the process elements illustrated in FIG. 12, the same reference numerals are assigned to the same components as those illustrated in FIG. 6.

  Referring to FIG. 12, the first roller 10 moves the completed diffuse reflection film 510 in a predetermined direction, and the second and third rollers 21 and 22 respectively move above and below the moving diffuse reflection film 510. Provided. The second and third rollers 21 and 22 coat the first and second UV adhesives 540 and 550 on the upper and lower surfaces of the diffuse reflection film 510, respectively, while rotating in a predetermined direction.

  The fourth and fifth rollers 31 and 32 are respectively provided above / below the diffuse reflection film 510 coated with the first and second UV adhesives 540 and 550. The fourth and fifth rollers 31 and 32 coat the first and second diffusion layers 520 and 530 on the lower surface of the first UV adhesive 540 and 550 and the upper surface of the second UV adhesive, respectively, while rotating in a predetermined direction. .

  The first and second UV irradiators 41 and 42 are respectively provided above / below the diffuse reflection film 510 coated with the first and second diffusion layers 520 and 530. The first and second UV irradiators 41 and 42 irradiate the diffuse reflection film 510 coated with the first and second diffusion layers 520 and 530 with UV light. The first and second UV adhesives 540 and 550 are cured by UV light, and fix the first and second diffusion layers 520 and 530 to the diffuse reflection film 510.

  Through such a process, the reflective polarizing member 501 including 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. 13 is a cross-sectional view showing a display device employing the reflective polarizing member shown in FIG. Of the constituent elements illustrated in FIG. 13, the same constituent elements as those illustrated in FIG. 9 are given the same reference numerals, and redundant description thereof is omitted.

  As shown in FIG. 13, the display device 402 includes a backlight assembly 200 that generates light, a reflective polarizing member 501 that reflects and polarizes light, and a display unit 300 that displays an image using light.

  The reflective polarizing member 501 is interposed between the display unit 300 and the backlight assembly 200. Of the light provided from the backlight assembly 200, the reflective polarizing member 501 transmits the P wave and diffuses and reflects the S wave to polarize the light. The light diffusely reflected by the reflective polarizing member 501 is reflected again by the backlight assembly 200 and further enters the reflective polarizing member 501. Such a series of processes is repeated, and 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 is added to prevent the phenomenon of wrinkling of the liquid crystal film. Is done.

  Therefore, the phenomenon of wrinkling of the reflective polarizing member can be prevented, and the overall luminance and luminance uniformity of the display device can be improved. As a result, the display quality of the display device can be improved.

  As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the embodiments, and as long as it has ordinary knowledge in the technical field to which the present invention belongs, without departing from the spirit and spirit of the present invention, The present invention can be modified or changed.

It is sectional drawing of the reflective polarizing member by one Example of this invention. FIG. 2 is a cross-sectional view specifically illustrating the liquid crystal film illustrated in FIG. 1. FIG. 3 is a diagram specifically illustrating a liquid crystal layer illustrated in FIG. 2. It is sectional drawing of the reflective polarizing member by the other Example of this invention. It is sectional drawing of the reflective polarizing member by further another Example of this invention. FIG. 5 is a process diagram illustrating a manufacturing process of the reflective polarizing member illustrated in FIG. 1. It is a figure which shows the state of UV adhesive agent before hardening. It is a figure which shows the state of UV adhesive agent after hardening. FIG. 2 is a cross-sectional view illustrating a display device that employs the reflective polarizing member illustrated in FIG. 1. It is sectional drawing of the reflective polarizing member by further another Example of this invention. FIG. 11 is a cross-sectional view of the organic particles illustrated in FIG. 10. FIG. 11 is a process diagram illustrating a manufacturing process of the reflective polarizing member illustrated in FIG. 10. FIG. 11 is a cross-sectional view illustrating a display device that employs the reflective polarizing member illustrated in FIG. 10.

Explanation of symbols

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, 530 Second diffusion layer 140, 540 First UV adhesive 150, 550 Second UV adhesive 200 Backlight Assembly 210 Multiple lamps 220 Diffusion plate 230 Diffusion sheet 240 First prism sheet 250 Second prism sheet 300 Display unit 310 Display panel 320 First polarization plate 330 Second polarization plate 401, 402 Display device 510 Diffuse reflection film

Claims (40)

A liquid crystal film composed of liquid crystal twisted in a predetermined direction, reflecting light parallel to the twist direction of the liquid crystal and transmitting the remaining light;
A diffusion layer attached to the liquid crystal film for diffusing the light;
A reflective deflecting member comprising: The diffusion layer is
A first diffusion layer attached to the lower surface of the liquid crystal film and diffusing light provided to the liquid crystal film;
A second diffusion layer attached to the upper surface of the liquid crystal film and diffusing the light emitted from the liquid crystal film;
The reflective polarizing member according to claim 1, comprising:   2. The reflective polarizing member according to claim 1, wherein the diffusion layer includes polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene.   The reflective polarizing member according to claim 1, further comprising a diffusing agent added to the diffusing layer to diffuse the light.   The reflective polarizing member according to claim 4, wherein the diffusing agent includes a silicon diffusing agent, a magnesium diffusing agent, or a calcium oxide diffusing agent.   The reflective polarizing member according to claim 1, further comprising a positive ion series surfactant contained in the diffusion layer to prevent charging of the liquid crystal film.   The reflective polarizing member according to claim 1, further comprising an adhesive formed of a UV curable material and attaching the diffusion layer to the liquid crystal film.   The adhesive is an acrylate, epoxy acrylate, polyester acrylate, or urethane acrylate photopolymerizable monomer, acrylate, epoxy acrylate, polyester acrylate, or urethane acrylate oligomer, and acetophenone or benzophenone. The reflective polarizing member according to claim 7, further comprising a photopolymerizable initiator based on thioxanthone. The liquid crystal film is
The base layer,
A liquid crystal layer provided on the base layer and made of cholesteric liquid crystal to circularly polarize the light;
A retardation layer that is provided on the liquid crystal layer and linearly polarizes the circularly polarized light;
The reflective polarizing member according to claim 1, comprising: The liquid crystal layer is
A first liquid crystal layer for circularly polarizing light in the red wavelength band;
A second liquid crystal layer for circularly polarizing light in the green wavelength band;
A third liquid crystal layer for circularly polarizing light in the blue wavelength band;
The reflective polarizing member according to claim 9, comprising:   The reflective polarizing member according to claim 10, wherein the first, second, and third liquid crystal layers are sequentially stacked on the base layer. The liquid crystal film is
A first adhesive for mounting the first liquid crystal layer on the base layer;
A second adhesive for mounting the second liquid crystal layer on the first liquid crystal layer;
A third adhesive for mounting the third liquid crystal layer on the second liquid crystal layer;
The reflective polarizing member according to claim 11, further comprising:   11. The reflective polarizing member according to claim 10, wherein the cholesteric liquid crystal and vertical alignment (VA) liquid crystal are mixed in the first liquid crystal layer at a ratio of 8: 2.   11. The reflective polarizing member according to claim 10, wherein the cholesteric liquid crystal and the VA liquid crystal are mixed in the second liquid crystal layer at a ratio of 7: 3.   11. The reflective polarizing member according to claim 10, wherein the cholesteric liquid crystal and the VA liquid crystal are mixed in the third liquid crystal layer at a ratio of 6: 4.   The reflective polarizing member according to claim 9, wherein the base layer is formed of a polyethylene terephthalate system. The retardation layer is a λ / 4 retardation layer,
10. The reflective polarizing member according to claim 9, wherein a z-axis refractive index, which is a thickness direction of the retardation layer, is larger than a refractive index of x-axis and y-axis on the surface of the λ / 4 retardation layer. .   The reflective polarizing member according to claim 17, wherein a phase retardation value of the retardation layer is 110 nm to 125 nm.   The reflective polarizing member according to claim 1, wherein the diffusion layer is attached to a lower surface of the liquid crystal film and diffuses the light provided to the liquid crystal film.   The reflective polarizing member according to claim 1, wherein the diffusion layer is attached to an upper surface of the liquid crystal film and diffuses the light emitted from the liquid crystal film. A diffusive reflective film that is stretched in a predetermined direction with a polymer resin and is composed of a large number of organic particles contained in the polymer resin, and selectively diffuses and reflects incident light by the organic particles;
A diffusion layer attached to the diffuse reflection film and diffusing the light;
A reflective polarizing member comprising: The diffusion layer is
A first diffusion layer attached to the lower surface of the diffuse reflection film and diffusing the light provided to the diffuse reflection film;
A second diffusion layer attached to the upper surface of the diffuse reflection film and diffusing the light emitted from the diffuse reflection film;
The reflective polarizing member according to claim 21, comprising:   The reflection layer according to claim 21, wherein the diffusion layer includes polycarbonate, polyethylene terephthalate, polyimide, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene. Polarizing member.   The reflective polarizing member according to claim 23, further comprising a diffusing agent that is added to the diffusing layer and diffuses the light.   The reflective polarizing member according to claim 24, wherein the diffusing agent includes a silicon diffusing agent, a magnesium diffusing agent, or a calcium oxide diffusing agent.   The reflective polarizing member according to claim 21, further comprising a positive ion series surfactant contained in the diffusion layer to prevent charging of the diffuse reflection film.   The reflective polarizing member according to claim 21, further comprising an adhesive made of a UV curable material and attaching the diffusion layer to the diffuse reflection film.   The adhesive is an acrylate, epoxy acrylate, polyester acrylate, or urethane acrylate photopolymerizable monomer, acrylate, epoxy acrylate, polyester acrylate, or urethane acrylate oligomer, and acetophenone or benzophenone. 28. The reflective polarizing member according to claim 27, further comprising a thioxanthone-based photopolymerizable initiator.   23. The polymer resin according to claim 21, wherein the polymer resin includes polycarbonate, polyethylene terephthalate, polyimide, polysulfone, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl alcohol, or polynorbornene. Reflective polarizing member.   The reflective polarizing member according to claim 21, wherein the organic particles are made of methacrylate butadiene styrene and have a core-shell structure. The core part of the organic particles is a part where butadiene and styrene are cross-linked,
31. The reflective polarizing member according to claim 30, wherein the shell portion of the organic particle is a portion surrounded by polymethyl methacrylate around the core portion. A backlight assembly that generates light;
A reflective polarizing member provided on the backlight assembly for selectively reflecting and polarizing the light;
A display panel provided on the reflective polarizing member and displaying an image using the polarized light;
The reflective polarizing member includes
A liquid crystal film composed of liquid crystal twisted in a predetermined direction, reflecting light parallel to the twist direction of the liquid crystal and transmitting the remaining light;
A diffusion layer attached to the liquid crystal film for diffusing the light;
A display device comprising: A backlight assembly that generates light;
A reflective polarizing member provided on the backlight assembly for selectively reflecting and polarizing the light;
A display panel provided on the reflective polarizing member and displaying an image using the polarized light;
The reflective polarizing member includes
A diffusive reflective film that is stretched in a predetermined direction with a polymer resin and is composed of a large number of organic particles contained in the polymer resin, and selectively diffuses and reflects incident light by the organic particles;
A diffusion layer attached to the diffuse reflection film to diffuse the light;
A display device comprising: Forming a liquid crystal film composed of liquid crystal twisted in a predetermined direction, reflecting light parallel to the twist direction of the liquid crystal and transmitting the remaining light;
Attaching a diffusion layer for diffusing the light to the liquid crystal film;
The manufacturing method of the reflective polarizing member characterized by the above-mentioned. The step of forming the liquid crystal film comprises:
Forming a liquid crystal layer composed of cholesteric liquid crystal on the base layer and circularly polarizing the light;
Curing the liquid crystal layer;
Forming a retardation layer that linearly polarizes the circularly polarized light on the cured liquid crystal layer;
The manufacturing method of the reflective polarizing member of Claim 34 characterized by the above-mentioned.   36. The method of manufacturing a reflective polarizing member according to claim 35, wherein the liquid crystal layer is formed of a mixed material in which a cholesteric liquid crystal and a VA liquid crystal are mixed in a solvent at a predetermined ratio and a UV initiator is added.   37. The method of manufacturing a reflective polarizing member according to claim 36, wherein the step of curing the liquid crystal layer comprises irradiating the liquid crystal layer containing the UV initiator with UV to cure the liquid crystal layer. The step of attaching the diffusion layer comprises:
Coating the liquid crystal film with a UV adhesive;
Coating the diffusion layer on the liquid crystal film coated with the UV adhesive;
Curing the UV adhesive to fix the diffusion layer to the liquid crystal film;
The manufacturing method of the reflective polarizing member of Claim 34 characterized by the above-mentioned. Stretching the polymer resin containing a large number of organic particles in a predetermined direction to form a diffuse reflection film of the organic particles having a core-shell structure;
Attaching a diffusion layer for diffusing the light to the diffuse reflection film;
The manufacturing method of the reflective polarizing member characterized by the above-mentioned. The step of attaching the diffusion layer comprises:
Coating the diffuse reflective film with a UV adhesive;
Coating the diffusion layer on the diffuse reflective film coated with the UV adhesive;
Curing the UV adhesive and attaching the diffusion layer to the diffuse reflective film;
The manufacturing method of the reflective polarizing member of Claim 39 characterized by the above-mentioned.

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