JP4135092B2 - Backlight and diffusion plate manufacturing method, and liquid crystal display device - Google Patents

Description

  The present invention relates to a method for manufacturing a backlight and a diffusion plate, and a liquid crystal display device, and more particularly to a method for manufacturing a backlight and a diffusion plate capable of reducing the number of parts and reducing the cost, and a liquid crystal display. Relates to the device.

  A liquid crystal display device is a liquid crystal display element (also referred to as an LCD panel) in which two transparent glass substrates are stacked so that the surfaces on which a transparent electrode and an alignment film are laminated face each other, and liquid crystal is sealed between the two substrates. And a backlight which is disposed under the liquid crystal display element and supplies light to the liquid crystal display element, a printed circuit board having a driving circuit for the liquid crystal display element, and these members are accommodated, and a liquid crystal display window is opened. And a metal frame.

  A light source such as a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED) is placed close to the backlight along the side surface of a light guide plate made of a transparent synthetic resin plate for guiding light. And a type in which a plurality of light sources such as cold cathode fluorescent lamps are arranged in parallel immediately below the liquid crystal display element. In the former, there is a diffusion plate for diffusing light between the light guide plate and the liquid crystal display element, and in the latter between the plurality of cold cathode fluorescent lamps and the liquid crystal display element, and irradiating the liquid crystal display element uniformly. Be placed.

  In a liquid crystal display device of a type in which a light source is disposed close to a side surface of a light guide plate, light emitted from the light source is guided by a light guide plate (sometimes referred to as a light guide), and a diffusion plate The light distribution is controlled by the lens film, and the liquid crystal display element is irradiated.

  Conventionally, a transparent lens film (also referred to as a lens sheet or a prism plate) having a prism surface on the upper surface and a smooth surface on the lower surface is disposed between the liquid crystal display element and the diffusion plate disposed therebelow. By doing so, the brightness of the display in the display device is increased to obtain a bright liquid crystal display screen with a uniform luminance distribution.

  In addition, BEF (Brightness Enhancement Film) (trademark) is widely used as a kind of lens film. Since the light diffused by the diffusion plate is condensed by the BEF toward the surface of the liquid crystal display element, a bright liquid crystal display screen with a uniform luminance distribution can be obtained. Examples of the cross-sectional shape of the prism surface of the lens film include a saw-tooth shape and a scallop shape.

  However, when a lens film is used to increase display brightness, moire may occur on the display screen due to interference between the liquid crystal display element and the lens film, and the display screen is viewed from an oblique direction. In some cases, mirror-like glare occurred.

  As a technique for increasing the luminance of the backlight to obtain a bright display screen with a uniform luminance distribution and preventing the occurrence of moire and glare on the display screen, for example, the upper surface has a light diffusing action and the lower surface has a lower surface. There is a technique of further disposing a second diffusion plate having a surface coated with a chemical mat layer between a lens film and a liquid crystal display element (for example, Patent Document 1).

Japanese Patent No. 3205393

  The technique disclosed in Patent Document 1 will be described with reference to FIG.

  1A is an exploded perspective view of a backlight of a liquid crystal display device, FIG. 1B is a cross-sectional view taken along the line AA ′ of the liquid crystal display device including the backlight of FIG. 1A, and FIG. It is a fragmentary sectional view of the lens film shown to 1A and FIG. 1B.

  The liquid crystal display element 21 is adapted to receive light emitted from the backlight 3 provided below the liquid crystal display element 21. The backlight 3 disposed under the liquid crystal display element 21 includes a second diffusion plate 1, a lens film 2, a first diffusion plate 12, a light guide plate 13, a reflection plate 14, and a cold cathode fluorescent lamp 11 that is a light source. The frame-like body 15 that holds these is molded by molding.

  The light guide plate 13 guides light emitted from the cold cathode fluorescent lamp 11 and emits light as uniformly as possible to each part of the first diffusion plate 12 provided on the upper surface (the first diffusion plate 12 side). Configuration (for example, white dots are printed on the bottom surface thereof, and a part of the guided light is reflected by the white dots, so that the light is emitted to the first diffusion plate 12 side. Configuration). The diffusion plate 12 diffuses the light emitted from the light guide plate 13. The reflection plate 14 totally reflects the light transmitted from the lower surface of the light guide plate 13 and makes it incident on the light guide plate 13 again.

  The lens film 2 is made of, for example, a polycarbonate film having a thickness of 0.36 mm, the lower surface (first diffusion plate 12 side) is a smooth surface 2b, and the upper surface (second diffusion plate 1 side) is, for example, A prism surface 2a is formed by arranging a large number of V-shaped stripe grooves having a cross-sectional shape as shown in FIG. 1C in parallel. The angle θ of the V-shaped stripe groove is an angle that satisfies the required light distribution performance, and is, for example, around 90 degrees (for example, 80 degrees to 100 degrees). The lens film 2 collects light diffusing at a large angle from the first diffusion plate 12 in a direction perpendicular to the display screen by the prism surface 2a.

  The second diffusion plate 1 disposed between the lens film 2 and the liquid crystal display element 21 is made of, for example, a polycarbonate film having a thickness of 0.25 mm, and the lower surface (the lens film 2 side) has a smooth surface 1b and the upper surface (liquid crystal). The display device 62 side) has a rough surface 1b by a well-known embossing process.

  As shown in FIG. 1, a lens film 2 having a prism surface 2a on the upper surface and a smooth surface 2b on the lower surface is disposed between the first diffusion plate 12 and the liquid crystal display element 21. Since the light diffused from the plate 12 at a large angle can be condensed in the direction perpendicular to the display screen by the prism surface 2a of the lens film 2, the luminance of the entire backlight 3 can be increased. In addition, since the diffusion direction can be reduced as a whole, a uniform luminance distribution can be maintained. Therefore, the light of the backlight 3 can be used efficiently, and a liquid crystal display screen with a bright and uniform luminance distribution can be obtained.

  In addition, the light that has passed through the lens film 2 is disposed between the lens film 2 and the liquid crystal display element 21 by disposing the second diffuser plate 1 having a rough surface 1a with an embossed upper surface and a smooth surface 1b on the lower surface. Is diffused by the rough surface 1a of the second diffusing plate 1 by the embossing process, so that the moire generated on the display screen due to the interference between the liquid crystal display element 21 and the lens film 2 or when the screen is viewed obliquely. It is possible to prevent the occurrence of mirror-like glare that occurs in the display and improve the display quality.

  The reflector 14, the light guide plate 13, the first diffuser plate 12, the lens film 2, and the second diffuser plate 1 are in a state of direct contact without providing a gap between the respective members. Is held in a recess provided in the.

  In addition, the lens film 2 and the first diffusion plate 12 may be integrally formed. For example, a diffusion layer is formed of a material in which diffusion particles are mixed into a transparent resin material on the lower surface side, and a prism surface is formed on the upper surface side. You may integrally form so that it may shape | mold.

  Next, a configuration example of a conventional liquid crystal display device in the case where a plurality of cold cathode fluorescent lamps are arranged in parallel immediately below the liquid crystal display element to form a light source will be described with reference to FIG.

  The liquid crystal display device includes a backlight 21 and an LCD panel 22.

  The LCD panel 22 receives light diffused by the backlight 21 and light distribution controlled.

  The backlight 21 includes fluorescent tubes 31-1 to 31-n, a diffusion plate 32, a rear frame 33, a reflection sheet 34, a diffusion sheet 35, and a BEF 36.

  Light emitted from the fluorescent tubes 31-1 to 31-n is diffused by the diffusion plate 32. Of the light emitted from the fluorescent tubes 31-1 to 31-n, the light emitted in the direction opposite to the diffusion plate 32 is attached to the fluorescent tube 31-1 to 31-n side of the rear frame 33. The light is reflected by the reflected sheet 34, enters the diffusion plate 32, and is diffused. The light diffused by the diffusion plate 32 is further diffused by the diffusion sheet 35 and enters a BEF (Brightness Enhancement Firm) 36. The BEF 36 has, on the upper surface (the LCD panel 22 side), for example, a prism surface formed by arranging a number of V-shaped stripe grooves having a sawtooth cross-sectional shape in parallel, and the lower surface (the diffusion sheet 35 side). Has a smooth surface shape, and condenses the diffused light emitted from the diffusion sheet 35 in the direction of the upper surface (LCD panel 22 side).

  The diffused light diffused by the diffusion sheet 35 enters the BEF 36 through the air layer. With reference to FIG. 3, incident light to the BEF 36 and outgoing light from the BEF 36 will be described.

  Assuming that the irradiation angle of the diffused light diffused by the diffusion sheet 35 to the BEF 36 is 0 to 90 degrees, the incident angle to the inside of the BEF 36 is an angle α determined by the refractive index of the BEF 36 and the air layer. When the resin constituting the BEF 36 is, for example, acrylic having a refractive index of 1.49, the incident angle of light into the BEF 36 is within a range of ± 42 degrees. The light that has entered the BEF 36 is emitted from the prism surface of the BEF 36 toward the upper surface (the LCD panel 22 side). The angle β constituting the prism surface is determined by the refractive index of the resin constituting the BEF 36 and the required light collecting characteristics.

  Hereinafter, when it is not necessary to distinguish the fluorescent tubes 31-1 to 31-n, they are simply referred to as a fluorescent tube 31.

  In the conventional backlight, as described above, in order to satisfy the light guiding performance and the light distribution performance, an extremely large number of parts are required, so that an assembling cost is required. On the other hand, there is a demand for further cost reduction by reducing the number of parts of the backlight.

  For example, according to the technique described with reference to FIG. 1, the reflection plate 14, the light guide plate 13, the first diffusion plate 12, the lens film 2, and the second diffusion plate 1 are in the recesses provided in the frame body 15. Since it is held, the number of parts is large and the assembly cost is increased. Patent Document 1 discloses that the lens film 2 and the first diffusion plate 12 are integrally formed. However, if the integral molding cannot be realized by a simple manufacturing method, it does not lead to cost reduction. In addition, depending on the type of resin used as a material, there may be a problem in the adhesiveness.

  Of course, in the case described with reference to FIG. 2, the same is true for the large number of parts, but the gap between the parts forming the air layer is accurately set for light diffusion and light distribution control. It was necessary to take, which was a factor in increasing the manufacturing cost.

  In addition, with the recent miniaturization of information processing devices, liquid crystal display devices are also required to be thin, and therefore it is desired to provide a light guide that is thinner than conventional light guides.

  The present invention has been made in view of such a situation, and is intended to provide a backlight that is thinner, more functional, and less expensive than a conventional backlight.

A first backlight of the present invention includes a light source that generates light, and a diffusion plate that is disposed between the light source and the liquid crystal display element, and the diffusion plate includes a diffusion layer that diffuses light generated from the light source; A light distribution layer that is integrated with the diffusion layer and disposed on the liquid crystal display element side from the diffusion layer, and distributes light diffused by the diffusion layer in the direction of the liquid crystal display element, and is integrated with the diffusion layer while being disposed on the light source side than the diffusion layer, is composed of light generated from the light source with a condensing layer for focusing, the diffusion layer comprises a Kakusanko, Haihikariso, condensing layer, and the diffusion The first resin constituting the portion other than the diffuser of the layer and the second resin constituting the diffuser are different resin materials. That is, the diffusion plate of the present invention is configured by integrally forming the diffusion layer and the light distribution layer. Further, as the light source, for example, a cold cathode fluorescent lamp or an LED can be used.

  The light distribution layer may have a prism shape on the surface on the liquid crystal display element side. Note that the prism shape of the light distribution layer may be a triangular shape, a sinusoidal shape, a semicircular shape, or an elliptical cross-sectional shape. Further, the prism shape of the light distribution layer may be a shape in which a plurality of triangular, sinusoidal, semicircular, elliptical, pyramid, and hemispherical units are arranged in the orthogonal X and Y directions, respectively. .

The first resin and the second resin may be a resin material having a refractive index of 1.2 to 1.7.

The light condensing layer may have a prism shape including a plurality of prisms having different shapes depending on the distance from the light source on the light source side surface.

In the first backlight of the present invention, light is generated and incident on the diffusion plate, and the light generated from the light source is collected by the condensing layer in the diffusion plate, and further, the light is transmitted by the diffusion layer. diffused, are light distribution in the light distribution layer, Haihikariso, together are configured integrally with the diffusion layer is disposed on the liquid crystal display element side than the diffusion layer, light-collecting layer is constituted integrally with the diffusion layer In addition, the first resin that is disposed closer to the light source than the diffusion layer, and includes a diffuser, and constitutes a portion other than the diffuser of the light distribution layer, the light collecting layer , and the diffusion layer , and the diffuser The second resin that constitutes a different resin material.

The first diffusion plate manufacturing method of the present invention includes a first injection step of injecting the first resin into the first cylinder, and a first resin in which a second resin different from the first resin is mixed. The first resin is injected by the processing of the second injection step of injecting the resin into the second cylinder, the third injection step of injecting the first resin into the third cylinder, and the first injection step. The first cylinder, the second cylinder into which the first resin mixed with the second resin by the process of the second injection step is injected, and the first resin by the process of the third injection step. A layer formed of the first resin, the first resin mixed with the second resin, and the first resin by multi-layer extrusion molding using the injected third cylinder, and appearing on the surface thereof. , Forming a three-layer sheet that is a layer made of the first resin on both sides The first molding step and the second molding for forming a prism shape by performing surface roll molding on one first resin surface of the sheets molded by the processing of the first molding step. And a third forming step for forming a prism shape by performing surface roll forming on the surface of the other first resin among the sheets formed by the processing of the first forming step. It is characterized by.

In the first diffusion plate manufacturing method of the present invention, the first resin is injected into the first cylinder, and the first resin mixed with the second resin different from the first resin is the second resin. Injected into the cylinder, the first resin is injected into the third cylinder, the first cylinder into which the first resin is injected, the second resin into which the first resin mixed with the second resin is injected Using the cylinder and the third cylinder into which the first resin is injected, the first resin mixed with the first resin and the second resin by the multilayer extrusion molding, and the first resin A three-layer sheet is formed, and the layers appearing on the surface are both layers of the first resin, and the surface roll molding is performed on the surface of one of the molded sheets. Is applied to form the prism shape, and the surface of the other first resin is Roll forming is subjected, the prism shape is formed.

The manufacturing method of the 2nd diffuser plate of this invention makes the 1st resin with which the 2nd resin was mixed by the process of the mixing step which mixes 2nd resin with 1st resin, and the process of the mixing step in the sheet form A first resin having a prism shape is molded using a 2P molding method so that the first molding step to be molded and one surface of the sheets molded by the first forming step are in contact with each other. The prism-shaped first resin is molded by using the 2P molding method so that the second molding step and the other surface of the sheets molded by the first forming step are in contact with each other. And a third molding step .

In the manufacturing method of the 2nd diffusion plate of this invention, 2nd resin is mixed with 1st resin, 1st resin with which 2nd resin was mixed is shape | molded in the sheet form, and the shape | molded sheet | seat Using the 2P molding method, the prism shape is molded from the first resin so as to be in contact with one side of the sheet, and so as to be in contact with the other side of the molded sheet. The prism-shaped first resin is molded using the 2P molding method.

A first liquid crystal display device of the present invention includes a liquid crystal display element and a backlight for illuminating the liquid crystal display element. The backlight includes a light source that generates light, and a light source between the light source and the liquid crystal display element. A diffusion layer disposed on the liquid crystal display element side of the diffusion layer and diffused by the diffusion layer. A light distribution layer that distributes the emitted light in the direction of the liquid crystal display element, and a condensing layer that is integrally formed with the diffusion layer and that is disposed closer to the light source than the diffusion layer and collects the light generated from the light source. The diffusion layer includes a diffuser, and includes a light distribution layer, a light collecting layer , and a first resin that forms a part other than the diffuser of the diffusion layer , and a second resin that forms the diffuser. Are different resin materials.

In the first liquid crystal display device of the present invention, a liquid crystal display element and a backlight for illuminating the liquid crystal display element are provided. In the backlight, light is generated, is incident on the diffusion plate, and is diffused. In the plate, the light generated from the light source is collected by the light collecting layer, diffused by the diffusion layer, and distributed by the light distribution layer. The light distribution layer is formed integrally with the diffusion layer, and the liquid crystal is formed by the diffusion layer. The light collecting layer is disposed on the display element side, and the light collecting layer is configured integrally with the diffusion layer, and is disposed on the light source side from the diffusion layer . The diffusion layer includes a diffuser, and the light distribution layer, the light collecting layer , and The first resin constituting the portion other than the diffuser of the diffusion layer and the second resin constituting the diffuser are different resin materials.

The second backlight of the present invention includes a light source that generates light, and a diffusion plate disposed between the light source and the liquid crystal display element, and the diffusion plate condenses light generated from the light source. and the layer, while being configured integrally with the condensed layer is disposed on the liquid crystal display element side of the light-collecting layer, the light condensed by the condensing optical layer between the light distribution layer for light distribution in the direction of the liquid crystal display device The condensing layer is configured to have a prism shape including a plurality of prisms having different shapes depending on the distance from the light source on the light source side surface .

  The light distribution layer may have a prism shape on the surface on the liquid crystal display element side.

In the second backlight of the present invention, a liquid crystal display element and a backlight for illuminating the liquid crystal display element are provided, and in the backlight, light is generated and incident on the diffusion plate, , The light generated from the light source is collected by the light collecting layer and distributed by the light distribution layer, and the light distribution layer is formed integrally with the light collecting layer, and is closer to the liquid crystal display element side than the light collecting layer. The condensing layer is arranged on the light source side surface and has a prism shape constituted by a plurality of prisms having different shapes depending on the distance from the light source .

A second liquid crystal display device of the present invention includes a liquid crystal display element and a backlight for illuminating the liquid crystal display element. The backlight includes a light source that generates light and a light source between the light source and the liquid crystal display element. A diffusing plate disposed, the diffusing plate is configured integrally with the condensing layer for condensing the light generated from the light source, and disposed on the liquid crystal display element side from the condensing layer, A light distribution layer that distributes light collected by the light collection layer in the direction of the liquid crystal display element, and the light collection layer is formed on a surface on the light source side by a plurality of prisms having different shapes depending on the distance from the light source. It has the prism shape comprised, It is characterized by the above-mentioned.

In the second liquid crystal display device of the present invention, a liquid crystal display element and a backlight for illuminating the liquid crystal display element are provided. In the backlight, light is generated and incident on the diffusion plate, and diffused. In the plate, the light generated from the light source is collected by the light collecting layer, and is distributed by the light distribution layer. The light distribution layer is formed integrally with the light collecting layer, and the liquid crystal display element side from the light collecting layer. The condensing layer has a prism shape composed of a plurality of prisms having different shapes depending on the distance from the light source on the light source side surface .

  According to the first aspect of the present invention, in the liquid crystal display device, it is possible to illuminate the liquid crystal display element, and it is possible to illuminate the liquid crystal display element particularly with a small number of parts and satisfying the required light distribution performance.

According to the second aspect of the present invention , a diffusion plate can be manufactured. In particular, a diffusion plate in which a light collecting layer, a diffusion layer, and a light distribution layer are integrally formed is used by multilayer extrusion molding and roll molding. Thus, it can be manufactured by a simple method.

According to the third aspect of the present invention , a diffusion plate can be manufactured. In particular, a diffusion plate in which a diffusion layer and a light distribution layer are integrally formed can be manufactured by a simple method using the 2P method. .

According to the fourth aspect of the present invention , a liquid crystal display device can be provided, and in particular, a liquid crystal display having a backlight that can illuminate a liquid crystal display element with a small number of components, satisfying a required light distribution performance. An apparatus can be provided.

According to the fifth aspect of the present invention , in the liquid crystal display device, the liquid crystal display element can be illuminated. In particular, the liquid crystal display element is illuminated with a small number of parts so as to increase the utilization efficiency of the emitted light. can do.

According to the sixth aspect of the present invention , it is possible to provide a liquid crystal display device, and in particular, a back that can illuminate the liquid crystal display element with a small number of parts so as to increase the utilization efficiency of emitted light. A liquid crystal display device having a light can be provided.

  Embodiments of the present invention will be described below. The correspondence relationship between the invention described in this specification and the embodiments of the invention is exemplified as follows. This description is intended to confirm that the embodiments supporting the invention described in this specification are described in this specification. Therefore, even if there is an embodiment that is described in the embodiment of the invention but is not described here as corresponding to the invention, the fact that the embodiment is not It does not mean that it does not correspond to the invention. Conversely, even if an embodiment is described herein as corresponding to an invention, that means that the embodiment does not correspond to an invention other than the invention. Absent.

  Further, this description does not mean all the inventions described in this specification. In other words, this description is for the invention described in the present specification, which is not claimed in this application, that is, for the invention that will be applied for in the future or that will appear and be added by amendment. It does not deny existence.

The backlight according to claim 1 (for example, the backlight 151 in FIG. 10 ) includes a light source that generates light (for example, the fluorescent tube 31 in FIG. 10 ) and a diffusion disposed between the light source and the liquid crystal display element. 10 (for example, the diffusion plate 161 of FIG. 10 or the diffusion plate 201 of FIG. 14), and the diffusion plate diffuses the light generated from the light source (for example, the diffusion of FIG . 10 or FIG. 14). Layer 82) and a light distribution layer (for example, a diagram ) arranged integrally with the diffusion layer and disposed closer to the liquid crystal display element than the diffusion layer, and distributes the light diffused by the diffusion layer in the direction of the liquid crystal display element . 10 or a light distribution layer 81) of FIG. 14 and a diffusion layer, and a light collection layer that is disposed closer to the light source than the diffusion layer and collects light generated from the light source , diffusion layer comprises Kakusanko, Haihikariso, light-collecting layer, and First resin constituting the portion other than the diffusion element of the diffusion layer (e.g., a first resin 101 in FIG. 12) and a second resin constituting the Kakusanko (e.g., a second resin 102 in FIG. 12) Is a different resin material.

The light-collecting layer according to claim 4 has a prism shape on the surface on the light source side, and the prism shape varies depending on the distance from the light source (for example, the light incident control unit 221 in FIG. 14). It is characterized by comprising.

The diffusion plate manufacturing method according to claim 5 is a first injection step (for example, step S43 in FIG. 11) for injecting the first resin into the first cylinder (for example, the first cylinder 105 in FIG. 12). And a second injection step of injecting a first resin mixed with a second resin different from the first resin into a second cylinder (for example, the first cylinder 106 in FIG. 12). For example, the process of step S43 in FIG. 11 and a third injection step (for example, step S43 in FIG. 11) for injecting the first resin into the third cylinder (for example, the first cylinder 181 in FIG. 12). Process), the first cylinder into which the first resin is injected by the process of the first injection step, and the first cylinder into which the first resin mixed with the second resin is injected by the process of the second injection step. 2 cylinders and a third note Using the third cylinder into which the first resin is injected by the processing of the step, the first resin mixed with the first resin and the second resin by the multilayer extrusion molding, and the first resin A first forming step (for example, the process of step S44 of FIG. 11) for forming a three-layer sheet that is configured and appears on the surface of which both layers are layers of the first resin, and a first forming step A second molding step (for example, the process of step S45 in FIG. 11) in which surface roll molding is performed on the surface of one of the first resins among the sheets molded by the process of The third molding step (for example, in FIG. 11) performs surface roll molding on the surface of the other first resin among the sheets molded by the processing of the first molding step, and molds the prism shape. Ste Characterized in that it comprises a processing flop S46).

In the manufacturing method of the diffusion plate according to claim 6 , the second resin is mixed by the mixing step of mixing the second resin with the first resin (for example, the process of step S63 in FIG. 13 ) and the process of the mixing step. A first molding step for molding the mixed first resin into a sheet shape (for example, the process of step S64 in FIG. 13 ) and one surface of the sheet molded by the first formation step are in contact with each other. Using the 2P molding method, the second molding step for molding the prism-shaped first resin (for example, the process of step S66 in FIG. 13 ) and the first forming step are performed so as to be integrated . A third molding step (for example, step S68 in FIG. 13) of molding the first resin in the prism shape using the 2P molding method so as to be in contact with the other surface of the sheet and to be integrated including the And wherein the door.

The liquid crystal display device according to claim 7 includes a liquid crystal display element and a backlight (for example, the backlight 151 in FIG. 10 ) for illuminating the liquid crystal display element, and the backlight is a light source that generates light ( For example, the fluorescent tube 31) in FIG. 10 and a diffusion plate (for example, the diffusion plate 161 in FIG. 10 or the diffusion plate 201 in FIG. 14) disposed between the light source and the liquid crystal display element are provided. Is formed integrally with the diffusion layer for diffusing the light generated from the light source (for example, the diffusion layer 82 in FIG . 10 or FIG. 14) and disposed on the liquid crystal display element side from the diffusion layer, A light distribution layer (for example, the light distribution layer 81 in FIG . 10 or FIG. 14) that distributes the light diffused by the diffusion layer in the direction of the liquid crystal display element, and the diffusion layer are integrated with the diffusion layer. Located on the light source side and generated from the light source Constituted by a light collecting layer for focusing the light, the diffusion layer, and includes a Kakusanko, Haihikariso, condensing layer, and a first resin constituting the portion other than the diffusion element of the diffusion layer, The second resin constituting the diffuser is a different resin material.

The backlight according to claim 8 (for example, the backlight 251 in FIG. 15) is a light source that generates light (for example, the fluorescent tube 31 in FIG. 15) and a diffusion disposed between the light source and the liquid crystal display element. A diffusion plate (for example, the diffusion plate 261 in FIG. 15), and the diffusion plate is integrated with the light collection layer (for example, the light incident control layer 211 in FIG. 15) and the light collection layer. A light distribution layer that is arranged on the liquid crystal display element side from the light collection layer and distributes the light collected by the light collection layer in the direction of the liquid crystal display element (for example, the light distribution layer 81 in FIG. 15). The condensing layer has a prism shape including a plurality of prisms having different shapes depending on the distance from the light source on the light source side surface.

A liquid crystal display device according to a tenth aspect includes a liquid crystal display element and a backlight for illuminating the liquid crystal display element (for example, the backlight 251 in FIG. 15), and the backlight is a light source that generates light ( For example, a fluorescent tube 31) in FIG. 15 and a diffusion plate (for example, the diffusion plate 261 in FIG. 15) disposed between the light source and the liquid crystal display element are provided, and the diffusion plate collects light generated from the light source. The light condensing layer (for example, the light incident control layer 211 in FIG. 15) and the condensing layer are integrated with each other, and the light is disposed on the liquid crystal display element side from the condensing layer and condensed by the condensing layer. The light collecting layer (for example, the light distribution layer 81 in FIG. 15) distributes light in the direction of the liquid crystal display element, and the condensing layer has a plurality of different shapes depending on the distance from the light source on the surface on the light source side. It has a prism shape composed of prisms. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 4 is a cross-sectional view for explaining a first configuration example of a liquid crystal display device having a backlight to which the present invention is applied.

  In addition, the same code | symbol is attached | subjected to the part corresponding to the conventional case, The description is abbreviate | omitted suitably.

  That is, the backlight 61 to which the present invention is applied is the same as the backlight 21 described with reference to FIG. 2 except that the diffusion plate 71 is provided instead of the diffusion plate 32, the diffusion sheet 35, and the BEF 36. It has a configuration.

  The diffusion plate 71 is provided with a diffusion layer 82 including a diffuser 91 on the side where the light emitted from the fluorescent tube 31 is incident, and the lower surface of the diffusion layer 82 (the fluorescent tube 31 side) has a smooth surface shape. On the LCD panel 22 side, that is, on the side from which most of the emitted light is emitted, for example, a large number of V-shaped stripe grooves having a sawtooth cross-sectional shape and irregularities having a kamaboko cross-sectional structure There is provided a light distribution layer 81 formed of a prism surface formed by arranging portions (for example, forming stripe grooves and uneven portions in parallel with each other). Specifically, the prism shape of the light distribution layer 81 may be a triangular shape, a sinusoidal shape, a semicircular shape, or an elliptical cross-sectional shape. Further, the prism shape of the light distribution layer 81 may be a shape in which a plurality of triangular, sinusoidal, semicircular, elliptical, pyramid, and hemispherical units are arranged in the orthogonal X and Y directions, respectively. Good.

  Part of the light incident on the diffusion layer 82 is incident on the surface of the diffuser 91, and the difference in refractive index between the resin constituting the diffuser layer 82 other than the diffuser 91 and the resin constituting the diffuser 91. Is partially reflected, and part of the light is incident on the diffuser 91 at a predetermined refractive index and is emitted from the diffuser 91 at a predetermined refractive index again. That is, the light incident on the diffusion layer 82 is diffused by the diffuser 91.

  The light diffused in the diffusion layer 82 is controlled in the direction of the LCD panel 22 by the light distribution layer 81.

  Of the diffuser plate 71, the light distribution layer 81 and the diffusion layer 82 in a portion other than the diffuser 91 are made of the same resin, and only the diffuser 91 is made of a different resin. Therefore, no light reflection or refraction occurs between the light distribution layer 81 and the diffusion layer 82. The light diffusion effect of the diffuser 91 is higher when the refractive index ratio of the resin constituting the diffusion layer 82 other than the light distribution layer 81 and the diffuser 91 and the resin constituting the diffuser 91 is higher. Is preferable.

  The first resin that constitutes the diffusion layer 82 other than the light distribution layer 81 and the diffuser 91 and the second resin that constitutes the diffuser 91 both have a refractive index of 1.2 to a refractive index of 1. Preferably, it is composed of 7 resins.

  Specifically, the first resin constituting the diffusion layer 82 other than the light distribution layer 81 and the diffuser 91 and the second resin constituting the diffuser 91 have a refractive index of 1.58 to 1.58, for example. 1.59 PC (Polycarbonate), refractive index 1.49 to 1.50 PMMA (PolyMethylMethAcrylate), or MS (methacryl styrene) with refractive index 1.56 to 1.58 Different resins, etc., among the resins).

  In the conventional case described with reference to FIGS. 2 and 3, the incident angle of light before light distribution control is limited by the difference in refractive index between the air layer and the BEF 36. On the other hand, unlike the conventional case described with reference to FIGS. 2 and 3, in the diffuser plate 71 to which the present invention is applied, the light diffusing portion and the light collecting portion are an air layer. Not through. That is, in the backlight 61 to which the present invention is applied, the diffused light is distributed without going through the air layer. For this reason, as shown in FIG. 5, the light reaching the light distribution layer 81 remains the diffusion angle diffused by the diffuser 91.

  Therefore, the light distribution performance required for the light distribution layer 81 is different from that of the BEF 36 that receives the diffused light through the conventional air layer. The prism shape of the light distribution layer 81 is optimized by the diffusion efficiency of the diffusion layer 82, the refractive index of the resin constituting the light distribution layer 81, and the light distribution performance required for the backlight 61.

  By having such a configuration, it is possible to provide a backlight capable of realizing necessary light distribution performance without using a diffusion sheet or the like in addition to the diffusion layer 82.

  Here, the case where the fluorescent tube 31 is used as the light source has been described, but it goes without saying that, for example, an LED (light emitting diode) may be used as the light source.

  Next, the diffusion plate manufacturing process 1 which is an example of the manufacturing process of the diffusion plate 71 will be described with reference to the flowchart of FIG. 6 and FIG. 7.

  In step S <b> 1, a first resin that forms the light distribution layer 81, the diffusion layer 82 in a portion other than the diffuser 91, and dots of the second resin that form the diffuser 91 are prepared.

  In step S <b> 2, in order to form the diffusion layer 82, dots of the second resin are mixed with the first resin. The diffuser 91 of the diffusion layer 82 is configured by the dots of the second resin mixed with the first resin.

  In step S3, in order to perform multilayer extrusion molding, the first resin is injected into the first cylinder, and the first resin mixed with the second resin is injected into the second cylinder. That is, as shown in FIG. 7A, the first resin 101 is injected into the first cylinder 105, and the first resin 101 in which the second resin 102 is mixed is injected into the second cylinder 106.

  In step S4, multilayer extrusion molding is performed by the multilayer extrusion molding apparatus.

  In principle, multilayer extrusion molding is a process where a resin material is fed into a heating cylinder (barrel) using a screw or plunger, and heated and fluidized to form a die at the tip (a gold with a cross-sectional hole for material passage). This is a method of making a long product by giving a shape through a mold and cooling and solidifying it with water or air. Depending on the shape of the die, molded products having various cross-sectional shapes such as films, sheets, pipes, and profiles (deformed materials) can be generated.

  Here, let the shape of die | dye be a shape for shape | molding a sheet | seat. As shown in FIG. 7A, the first resin 101 is injected into the first cylinder 105, and the first resin 101 in which the second resin 102 is mixed is injected into the second cylinder 106. Therefore, a two-layer sheet of the diffusion layer 82 and the layer (the first resin 101 on which the prism is not formed) serving as the base of the light distribution layer 81 is formed by extrusion molding.

  In step S5, as shown in FIG. 7B, among the sheets generated by the multilayer extrusion molding apparatus, the first resin side extruded by the first cylinder (in FIG. 7B, the surface roll 107 side in the figure). In addition, surface roll molding is performed using the surface roll 107, the prism shape is formed on the first resin 101, and the light distribution layer 81 in contact with the diffusion layer 82 is formed. The manufacturing process of the diffusion plate 71 having no air layer between the layer 82 is completed.

  Next, with reference to the flowchart of FIG. 8 and FIG. 9, the diffusion plate manufacturing process 2, which is an example different from the diffusion plate manufacturing process 1 described with reference to FIGS. 6 and 7, among the manufacturing processes of the diffusion plate 71. Will be described.

  In step S <b> 21, a first resin that constitutes the diffusion layer 82 other than the light distribution layer 81 and the diffuser 91 and a second resin dot that constitutes the diffuser 91 are prepared.

  In step S <b> 22, a UV curing agent is mixed into the first resin 101 that constitutes the light distribution layer 81. Note that this step is omitted when the first resin is a UV curable resin.

  In step S <b> 23, dots of the second resin 102 are mixed with the first resin 101 in order to form the diffusion layer 82. The diffuser 91 of the diffusion layer 82 is configured by the dots of the second resin 102 mixed with the first resin 101.

  In step S24, the first resin 101 mixed with the second resin 102 is formed into a sheet shape using, for example, an extrusion molding method or a calendar molding method. The diffusion layer 82 is configured by the resin sheet thus molded.

  In step S25, the first resin 101 mixed with the second resin 102 formed into a sheet is mixed with the UV curing agent or the first resin 101 which is a UV curable resin is applied. .

  In step S <b> 26, a prism shape determined by the shape of the mold 121 is formed on the first resin 101 mixed with a UV curing agent or a UV curable resin by a 2P molding method, and the light distribution layer 81. And the manufacturing process of the diffusion plate 71 having no air layer between the light distribution layer 81 and the diffusion layer 82 is completed.

  The 2P molding method is a method in which a low-viscosity UV curable resin is used and a mold shape is transferred and replicated on the resin. Specifically, a UV curable resin is applied between an electroforming mold (stamper) and a substrate glass, and the resin is UV cured by irradiating with ultraviolet rays to be molded into a desired shape.

  The diffusion plate 71 included in the backlight 61 of FIG. 4 is manufactured by the manufacturing process described with reference to FIGS.

  FIG. 10 is a cross-sectional view for explaining a second configuration example of a liquid crystal display device having a backlight to which the present invention is applied.

  In addition, the same code | symbol is attached | subjected to the part corresponding to the case in the 1st structural example demonstrated using FIG. 4, The description is abbreviate | omitted suitably.

  That is, the backlight 151 of the second configuration example to which the present invention is applied has the same configuration as the backlight 61 described with reference to FIG. 4 except that the diffusion plate 161 is provided instead of the diffusion plate 71. It is what you have.

  In addition to the light distribution layer 81 and the diffusion layer 82 similar to the diffusion plate 71, the diffusion plate 161 has, for example, a large number of V-shaped stripe grooves having a sawtooth cross-sectional shape, and a semi-cylindrical shape on the fluorescent tube 31 side. There is provided a light incident control layer 171 configured by a prism surface formed by arranging uneven portions having a cross-sectional structure in parallel. The light incident control layer 171 is made of the same resin (the first resin 101 in FIG. 7 or FIG. 9) as the light distribution layer 81 and the diffusion layer 82 other than the diffuser 91, and only the diffuser 91 is different. Consists of resin. Therefore, no reflection or refraction of light occurs between the light incident control layer 171 and the diffusion layer 82. Further, the prism shape of the light incident control layer 171 may be the same as or different from the prism shape of the light distribution layer 81.

  The shape of the prism of the light incident control layer 171 can efficiently guide the light emitted from the fluorescent tube 31 or the light emitted from the fluorescent tube 31 and reflected by the reflection sheet 34 to the diffusion layer 82. It is made like this. The ratio of the light that has entered the light incident control layer 171 out of the light that has reached the light incident control layer 171 is assumed to be random when the incident angle is random. It depends on the ratio of the refractive indices of the two. By forming the prism on the light incident control layer 171, other light that has reached the surface of the light incident control layer 171 and is reflected without being incident on the light incident control layer 171. It is possible to increase the ratio of light that is irradiated again on the surface of the portion.

  Therefore, the diffusion plate 161 in the second configuration example is configured to include the light incident control layer 171 as compared with the diffusion plate 71 in the first configuration example. The ratio of light that does not reach the diffusion layer 82 and is lost can be reduced, and light diffusion, light distribution control, and light collection control can be realized with a single diffusion plate.

  By having such a configuration, the backlight 151 realizes necessary light distribution performance without using a diffusion sheet in addition to the diffusion layer 82, and suppresses the loss of light generated by the fluorescent tube 31. be able to.

  Next, the diffusion plate manufacturing process 3 which is an example of the manufacturing process of the diffusion plate 161 is demonstrated using the flowchart of FIG. 11, and FIG.

  In step S <b> 41, the dots of the light distribution layer 81, the light incident control layer 171, and the first resin 101 constituting the diffusion layer 82 other than the diffuser 91 and the second resin 102 constituting the diffuser 91. And are prepared.

  In step S <b> 42, dots of the second resin 102 are mixed with the first resin 101 to form the diffusion layer 82. The diffuser 91 of the diffusion layer 82 is configured by the dots of the second resin 102 mixed with the first resin 101.

  In step S43, in order to perform multilayer extrusion molding, the first resin 101 is injected into the first cylinder and the third cylinder, and the first resin 101 mixed with the second resin 102 is injected into the second cylinder. The That is, in the manufacturing process of the diffusion plate 161, three cylinders are used. As shown in FIG. 12A, the first resin 101 is injected into the first cylinder, and the second resin 102 is injected into the second cylinder. The first resin 101 mixed with is injected, and the first resin 101 is injected into the third cylinder. The third cylinder is provided at a position opposite to the first cylinder with respect to the second cylinder.

  In step S44, multilayer extrusion molding is performed by the multilayer extrusion molding apparatus. Here, the first resin 101 is injected into the first cylinder, the first resin 101 mixed with the second resin 102 is injected into the second cylinder, and the first resin 101 is injected into the third cylinder. Therefore, by extrusion molding, it becomes the source of the light distribution layer 81 (first resin 101 on which the prism is not molded), the diffusion layer 82, and the light incident control layer 171 ( A sheet composed of three layers of the first resin 101) layer on which the prism is not molded is molded.

  In step S45, similarly to the case described with reference to FIG. 7B, the surface roll 107 is used on the first resin 101 side extruded by the first cylinder among the sheets generated by the multilayer extrusion molding apparatus. Then, surface roll molding is performed, and a prism shape is molded on the first resin 101 to form a light distribution layer 81 in contact with the diffusion layer 82.

  In step S46, as shown in FIG. 12B, among the sheets generated by the multilayer extrusion molding apparatus, the first resin 101 side extruded by the third cylinder (in other words, the arrangement formed in step S45). A surface roll 107 is applied to a surface different from the optical layer 81 using a surface roll 107, a prism shape is formed on the first resin 101, and the light incident control layer 171 in contact with the diffusion layer 82 is formed. The manufacturing process of the diffusion plate 161 that is configured and does not have an air layer between the light distribution layer 81, the diffusion layer 82, and the light incident control layer 171 is completed.

  Next, the diffusion plate manufacturing process 4 which is an example different from the diffusion plate manufacturing process 3 described using FIG. 11 in the flowchart of FIG. 13 and the manufacturing process of the diffusion plate 161 will be described.

  In step S <b> 61, the dots of the light distribution layer 81, the light incident control layer 171, and the first resin 101 that constitutes the diffusion layer 82 other than the diffuser 91 and the second resin 102 that constitutes the diffuser 91. And are prepared.

  In step S <b> 62, a UV curing agent is mixed into the first resin 101 that constitutes the light distribution layer 81 and the light incident control layer 171. Note that this step is omitted when the first resin is a UV curable resin.

  In step S <b> 63, dots of the second resin 102 are mixed with the first resin 101 in order to form the diffusion layer 82. The diffuser 91 of the diffusion layer 82 is configured by the dots of the second resin 102 mixed with the first resin 101.

  In step S64, the first resin 101 mixed with the second resin is molded into a sheet shape using, for example, an extrusion molding method or a calendar molding method. The diffusion layer 82 is configured by the resin sheet thus molded.

  In step S65, a UV curing agent is mixed with one surface of the first resin 101 mixed with the second resin 102 formed into a sheet shape, or the first resin 101 is a UV curable resin. Resin 101 is applied.

  In step S <b> 66, the light distribution layer 81 is configured by forming a prism shape on the first resin 101 that is mixed with a UV curing agent or is a UV curable resin by a 2P molding method.

  In step S67, the surface of the first resin 101 (diffusion layer 82) mixed with the second resin 102 formed into a sheet shape is formed with a prism by the process of step S66 (that is, the light distribution layer 81). A first resin 101 in which a UV curing agent is mixed or is a UV curable resin is applied to a different surface.

  In step S68, the UV curing agent is mixed by the 2P molding method, or the prism shape is molded on the first resin 101 which is a UV curable resin, the light incident control layer 171 is configured, and the light distribution layer 81 is formed. Then, the manufacturing process of the diffusion plate 161 having no air layer between the diffusion layer 82 and the light incident control layer 171 is completed.

The diffusion plate 161 included in the backlight 151 of FIG. 10 is manufactured by the manufacturing process described with reference to FIG. 11 or FIG.

  Further, a diffusion plate 201 as shown in FIG. 14 may be used in place of the diffusion plate 161 of FIG.

  The diffusing plate 201 includes a light distribution layer 81 and a diffusing layer 82 similar to the diffusing plate 161, and includes a light incident control layer 211 having a different prism shape instead of the light incident control layer 171.

  A light incident control unit 221 is configured on the prism on the fluorescent tube 31 side of the light incident control layer 211 (in FIG. 14, two light incident control units 221 of the light incident control units 221-1 and 221-2 are provided. The shape is determined by the distance from the closest one of the fluorescent tubes 31-1 to 31-n.

  The incident portion of the light emitted from the fluorescent tube 31 is a flat plane as in the diffusion plate 71 in FIG. 4, or the fluorescent tube as in the light incident control layer 171 provided on the diffusion plate 161 in FIG. When the prism shape for condensing the light emitted from 31 is constant, the planar shape of the LCD panel 22 is directly above any one of the fluorescent tubes 31-1 to 31-n and the fluorescent tube 31- The distribution of the incident angle of the light emitted from the fluorescent tube 31 to the diffusion plate 71 or the diffusion plate 161 differs depending on the position between any two of 1 to 31-n. May occur.

  In the conventional backlight, the brightness in the LDC panel plane is made uniform by reducing the brightness of the bright part. On the other hand, in the diffuser plate 201, more light is emitted from the diffuser plate 201 at a position where the brightness is lowered, that is, at a position between any two of the fluorescent tubes 31-1 to 31-n. It is designed to be incident on the inside.

  That is, in the diffusing plate 201, by forming a prism on the fluorescent tube 31 side of the light incident control layer 211, the luminance of the light irradiated to the LCD panel 22 can be improved, and in addition, the fluorescent tube 31- By optimizing the prism shape based on the arrangement of 1 to 31-n, it is possible to improve backlight unevenness.

  FIG. 15 is a cross-sectional view for explaining a third configuration example of a liquid crystal display device having a backlight to which the present invention is applied.

  In addition, the same code | symbol is attached | subjected to the part corresponding to the case in the 1st structural example demonstrated using FIG. 4, The description is abbreviate | omitted suitably.

  That is, the backlight 251 of the third configuration example to which the present invention is applied has the same configuration as the backlight 61 described with reference to FIG. 4 except that the diffusion plate 261 is provided instead of the diffusion plate 71. It is what you have.

  The diffusion plate 261 has the same configuration as the diffusion plate 201 described with reference to FIG. 14 except that the diffusion layer 82 is omitted. That is, the diffusion plate 261 is configured by the light distribution layer 81 and the light incident control unit 211. Further, no light reflection or refraction occurs between the light incident control unit 211 and the light distribution layer 81.

  By omitting the diffusion layer 82 from the diffusion plate 261, the light transmittance of the diffusion plate 261 becomes higher than that of the diffusion plate 71, the diffusion plate 161, or the diffusion plate 201. In such a configuration, the uniformity of the light emitted to the LCD panel 22 by the backlight 251 is a combination of the light distribution performance of the light distribution layer 81 and the light collection performance of the light incident control unit 211. Therefore, it is possible to obtain desired performance by optimizing the shapes of the prisms of the light distribution layer 81 and the light incident control unit 211.

  By having such a configuration, the necessary light distribution performance can be realized without using a diffusion sheet or the like other than the diffusion layer 82, and the light transmittance is further increased. Therefore, it is possible to provide a high-luminance backlight that can efficiently use the light generated by the.

  As described above, in the backlight to which the present invention is applied, since a high-performance diffuser plate having a diffusion function and a light distribution function can be integrally formed, the number of parts of the backlight is reduced, and the parts Costs can be reduced. Further, in the conventional backlight, since each part is assembled so that an air layer is formed between the diffusion plate, the diffusion sheet, and the lens sheet, high accuracy is required for the assembly. However, in the backlight to which the present invention is applied, a high-performance diffuser plate having a diffusion function and a light distribution function must be integrally manufactured by a simple method. Therefore, it is possible to reduce the assembly cost.

  In the above-described backlight to which the present invention is applied, the rear frame 33 is described as being provided with the reflective sheet 34. However, the reflective sheet 34 is located at a position other than that illustrated in FIG. Needless to say, the present invention can be applied even when the reflective sheet 34 is not provided.

It is a figure for demonstrating the structure of the backlight using the conventional light guide. It is a figure for demonstrating the structure of the backlight using the conventional fluorescent tube. It is a figure for demonstrating the light which injects into BEF via an air layer. It is a figure for demonstrating the 1st structural example of the backlight to which this invention is applied. It is a figure for demonstrating the light distribution performance of the diffusion plate to which this invention is applied. 5 is a flowchart for explaining a diffusion plate manufacturing process 1; It is a figure for demonstrating the diffusion plate manufacturing process 1. FIG. 5 is a flowchart for explaining a diffusion plate manufacturing process 2; It is a figure for demonstrating the diffusion plate manufacturing process 2. FIG. It is a figure for demonstrating the 2nd structural example of the backlight to which this invention is applied. 10 is a flowchart for explaining a diffusion plate manufacturing process 3; It is a figure for demonstrating the diffusion plate manufacturing process 3. FIG. 10 is a flowchart for explaining a diffusion plate manufacturing process 4; It is a figure which shows the example of the light distribution plate which can be used instead of the light distribution plate of FIG. It is a figure for demonstrating the 3rd structural example of the backlight to which this invention is applied.

Explanation of symbols

  22 LCD panel, 31 fluorescent tube, 33 rear frame, 34 reflection sheet, 61 backlight, 71 diffuser plate, 81 light distribution layer, 82 diffusion layer, 91 diffuser, 101 first resin, 102 second resin, 105 1st cylinder, 106 2nd cylinder, 107 surface roll, 121 mold, 151 backlight, 161 diffuser plate, 171 light incident control layer, 181 third cylinder, 201 diffuser plate, 211 light incident control layer, 221 Light incident control unit, 251 backlight, 261 diffuser

Claims (10)

A light source that generates light;
In a backlight comprising a diffusing plate disposed between the light source and the liquid crystal display element,
The diffusion plate is
A diffusion layer for diffusing the light generated from the light source;
A light distribution layer configured integrally with the diffusion layer, disposed on the liquid crystal display element side from the diffusion layer, and distributes the light diffused by the diffusion layer toward the liquid crystal display element ;
Constructed integrally with the diffusion layer, arranged on the light source side from the diffusion layer, and constituted by a condensing layer for condensing the light generated from the light source ,
The diffusion layer includes a diffuser,
The first resin constituting the light distribution layer, the light collecting layer, and the diffusion layer other than the diffuser and the second resin constituting the diffuser are different resin materials. Backlight characterized by. The backlight according to claim 1, wherein the light distribution layer has a prism shape on a surface on the liquid crystal display element side. The backlight according to claim 1, wherein the first resin and the second resin are resin materials having a refractive index of 1.2 to 1.7. The backlight according to claim 1 , wherein the condensing layer has a prism shape including a plurality of prisms having different shapes depending on a distance from the light source on a surface on the light source side. In a manufacturing method of a diffusion plate provided in a liquid crystal display device and provided in a backlight for illuminating a liquid crystal display element,
A first injection step of injecting a first resin into the first cylinder;
A second injection step of injecting the first resin mixed with a second resin different from the first resin into a second cylinder;
A third injection step of injecting the first resin into a third cylinder;
The first cylinder into which the first resin has been injected by the process of the first injection step, and the first resin in which the second resin has been mixed by the process of the second injection step are injected. In addition, the second resin and the third cylinder into which the first resin has been injected by the processing of the third injection step are used to perform the first resin and the second resin by multilayer extrusion molding. The first resin formed by mixing the first resin and the first resin, and a first layer forming a three-layer sheet in which the layers appearing on the surface are both layers of the first resin. A molding step;
Of the sheet formed by the processing of the first forming step, a second forming step of applying surface roll forming to the surface of one of the first resins and forming a prism shape;
A third forming step of forming a prism shape by performing surface roll forming on the surface of the other first resin of the sheet formed by the processing of the first forming step. A manufacturing method of a diffusion plate characterized by the above. In a manufacturing method of a diffusion plate provided in a liquid crystal display device and provided in a backlight for illuminating a liquid crystal display element,
A mixing step of mixing the second resin with the first resin;
A first molding step of molding the first resin mixed with the second resin by the processing of the mixing step into a sheet;
A second molding step of molding the prism-shaped first resin by using a 2P molding method so as to be in contact with and integrated with one surface of the sheet molded by the first forming step. When,
Third molding step of molding the prism-shaped first resin by using a 2P molding method so as to be in contact with and integrated with the other surface of the sheet molded by the first forming step. method for manufacturing a diffuser plate which comprises and. A liquid crystal display element;
A backlight for illuminating the liquid crystal display element,
The backlight is
A light source that generates light;
A diffusion plate disposed between the light source and the liquid crystal display element,
The diffusion plate is
A diffusion layer for diffusing the light generated from the light source;
A light distribution layer configured integrally with the diffusion layer, disposed on the liquid crystal display element side from the diffusion layer, and distributes the light diffused by the diffusion layer toward the liquid crystal display element ;
Constructed integrally with the diffusion layer, arranged on the light source side from the diffusion layer, and constituted by a condensing layer for condensing the light generated from the light source ,
The diffusion layer includes a diffuser,
The first resin constituting the light distribution layer, the light collecting layer, and the diffusion layer other than the diffuser and the second resin constituting the diffuser are different resin materials. A liquid crystal display device. In a backlight for illuminating a liquid crystal display element provided in a liquid crystal display device,
A light source that generates light;
A diffusion plate disposed between the light source and the liquid crystal display element,
The diffusion plate is
A condensing layer for condensing the light generated from the light source;
A light distribution that is integrated with the light condensing layer, is disposed closer to the liquid crystal display element than the light condensing layer, and distributes the light condensed by the light condensing layer in the direction of the liquid crystal display element Composed of layers and
The light condensing layer has a prism shape composed of a plurality of prisms having different shapes depending on the distance from the light source on the light source side surface. The backlight according to claim 8 , wherein the light distribution layer has a prism shape on a surface on the liquid crystal display element side. A liquid crystal display element;
A backlight for illuminating the liquid crystal display element,
The backlight is
A light source that generates light;
A diffusion plate disposed between the light source and the liquid crystal display element,
The diffusion plate is
A condensing layer for condensing the light generated from the light source;
A light distribution that is integrated with the light condensing layer, is disposed closer to the liquid crystal display element than the light condensing layer, and distributes the light condensed by the light condensing layer in the direction of the liquid crystal display element Composed of layers and
The light condensing layer has a prism shape including a plurality of prisms having different shapes depending on a distance from the light source on a surface on the light source side.

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