JP2014142368A - Light diffusion member and manufacturing method of the same, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusion member that can obtain desired optical performance without complicating a manufacturing process.SOLUTION: A light diffusion member 7 according to the present invention comprises: a base material 39 that has transmissivity; a plurality of light diffusion sections 40 that is formed on one surface of the base material 39; and a light shield layer 41 that is formed in a region other than a region having the light diffusion sections 40 formed on one surface of the base material 39. The light diffusion section 40 has a light exit end surface on the base material side 39, and a light incident end surface having an area larger than an area of the light exit end surface on an opposite side of the base material 39 side. A height of the light diffusion section 40 from the light incident end surface to the light exit end surface is larger than a layer thickness of the light shield layer 41, and the light diffusion section 40 is formed of a plurality of layers made of a plurality of types of materials having incompatibility.

Description

  The present invention relates to a light diffusing member, a manufacturing method thereof, and a display device.

  A liquid crystal display device is widely used as a display of a portable electronic device such as a mobile phone or a television or a personal computer. However, in general, liquid crystal display devices are known to have excellent visibility from the front, but have a narrow viewing angle. Various devices have been devised for widening the viewing angle. As one of them, a configuration in which a member for diffusing light emitted from a display body such as a liquid crystal panel (hereinafter referred to as a light diffusing member) is provided on the viewing side of the display body can be considered.

  For example, Patent Document 1 discloses a light diffusing sheet that includes a sheet main body and a plurality of substantially wedge-shaped portions that are embedded on the emission surface side in the sheet main body and expand toward the emission surface side. In this light diffusing sheet, the side surface of the substantially wedge-shaped portion is formed by a folded surface, and the angle formed by each folded surface of the side surface and the perpendicular of the incident surface increases as the surface approaches the exit surface side. In this light diffusing sheet, the side surface of the substantially wedge-shaped portion is configured as described above, so that the light incident perpendicularly to the incident surface is totally reflected on the side surface a plurality of times to increase the diffusion angle.

JP 2005-157216 A

  When manufacturing the light diffusing sheet described in Patent Document 1, it is extremely difficult to form a substantially wedge-shaped portion having a side surface composed of a plurality of bent surfaces on the sheet body. In addition, it is complicated to embed a UV curable resin or the like in the substantially wedge-shaped portion without a gap after forming the substantially wedge-shaped portion in the sheet body, and the manufacturing process becomes complicated. There is a problem that the desired light diffusing performance cannot be obtained if problems such as the inclination angle of the bent surface cannot be formed with high accuracy or the resin is not sufficiently embedded in the substantially wedge-shaped portion.

  The present invention has been made to solve the above problems, and provides a light diffusing member capable of obtaining a desired light diffusing performance without complicating the manufacturing process, and a method for manufacturing the same. Objective. It is another object of the present invention to provide a display device that includes the light diffusing member and has excellent display quality.

  In order to achieve the above object, the light diffusing member of the present invention includes a light-transmitting base material, a plurality of light diffusing portions formed on one surface of the base material, and the light on one surface of the base material. A light shielding layer formed in a region other than the region where the diffusion portion is formed, and the light diffusion portion has a light emission end surface on the substrate side and an area of the light emission end surface on the side opposite to the substrate side A light incident end surface having a larger area than the light incident end surface of the light diffusing portion is higher than the thickness of the light shielding layer, and the light diffusing portion has a plurality of types. It is characterized by being formed of a plurality of layers of a material having incompatibility.

  The light diffusing member of the present invention is characterized in that the inclination angles of the side surfaces of the plurality of layers of the light diffusing portion are different from each other.

  The light diffusing member of the present invention is characterized in that the refractive indexes of the materials of the plurality of layers of the light diffusing portion are different from each other.

  The light diffusing member of the present invention is characterized in that the interfaces of the plurality of layers of the light diffusing portion are non-parallel to one surface of the substrate.

  The light diffusing member of the present invention is characterized in that the inclination angle of the side surfaces of the plurality of layers of the light diffusing portion becomes larger as it approaches the light incident end surface side.

  The light diffusing member of the present invention is characterized in that air exists in a gap between the plurality of light diffusing portions.

  In the light diffusing member of the present invention, the plurality of light diffusing portions are arranged in a stripe shape with a space from each other when viewed from the normal direction of the one surface of the substrate, and the light shielding layer is formed on one surface of the substrate. It is characterized by being arranged in a stripe shape between the light diffusion portions arranged in the stripe shape as viewed from the normal direction.

  The light diffusing member of the present invention is characterized in that at least one of a short dimension of the plurality of light diffusing portions and a short dimension of the plurality of light shielding layers is set at random.

  In the light diffusing member of the present invention, the plurality of light diffusing portions are arranged in a dotted manner when viewed from the normal direction of one surface of the base material, and the light shielding layer is a region other than the region where the light diffusing portion is formed. It is characterized by being formed continuously.

  The light diffusing member of the present invention is characterized in that the plurality of light diffusing portions are regularly arranged as viewed from the normal direction of one surface of the substrate.

  The light diffusing member of the present invention is characterized in that the plurality of light diffusing portions are aperiodically arranged when viewed from the normal direction of one surface of the base material.

  The light diffusing member of the present invention is characterized in that the plurality of light diffusing portions have the same shape as seen from the normal direction of one surface of the substrate.

  The light diffusing member of the present invention is characterized in that the plurality of light diffusing portions have an indefinite shape when viewed from the normal direction of one surface of the substrate.

  The light diffusing member of the present invention is characterized in that the planar shape of the light diffusing portion viewed from the normal direction of one surface of the substrate is a circle, an ellipse or a polygon.

  The light diffusing member of the present invention is characterized in that the substrate has light diffusibility.

  The light diffusing member of the present invention is formed in a region other than a region where the light shielding layer is formed on one surface of the substrate, a plurality of light shielding layers formed on one surface of the substrate, and a light transmissive substrate. The light diffusing portion has a light emitting end surface on the base material side and a light incident end surface having an area larger than the area of the light emitting end surface on the side opposite to the base material side. A height from the light incident end face to the light exit end face of the light diffusing portion is larger than a layer thickness of the light shielding layer, and the light diffusing portion includes a plurality of types of incompatible materials. It is characterized by being formed of layers.

  In the light diffusing member of the present invention, the plurality of light shielding layers are arranged in a scattered manner when viewed from the normal direction of one surface of the base material, and the light diffusing portion is located in a region other than the region where the light shielding layer is formed. It is characterized by being formed continuously.

  The light diffusing member of the present invention is characterized in that the plurality of light shielding layers are regularly arranged as viewed from the normal direction of one surface of the substrate.

  The light diffusing member of the present invention is characterized in that the plurality of light shielding layers are aperiodically arranged when viewed from the normal direction of one surface of the base material.

  The light diffusing member of the present invention is characterized in that the plurality of light shielding layers have the same shape as seen from the normal direction of one surface of the substrate.

  The light diffusing member of the present invention is characterized in that the plurality of light shielding layers have an indefinite shape when viewed from the normal direction of one surface of the substrate.

  The light diffusing member of the present invention is characterized in that the planar shape of the light shielding layer viewed from the normal direction of one surface of the substrate is a circle, an ellipse or a polygon.

  The method for producing a light diffusing member of the present invention comprises a step of forming a light shielding layer having an opening on one surface of a light-transmitting substrate, and a negative photosensitive material obtained by mixing a plurality of incompatible materials with each other. Adjusting the resin material, disposing the negative photosensitive resin material on one surface of the base material so as to cover the light shielding layer, phase-separating the negative photosensitive resin material, and Forming a plurality of negative photosensitive resin layers separated in the normal direction of one surface of the material, and a surface opposite to the one surface of the substrate on which the light shielding layer and the plurality of negative photosensitive resin layers are formed The step of exposing the plurality of negative photosensitive resin layers through the openings of the light shielding layer, and developing the plurality of negative photosensitive resin layers after the exposure, the light emitting end face on the substrate side And the light exit end face on the side opposite to the substrate side. Characterized by comprising the steps of forming a plurality of the light diffusing portion on a surface of the base substrate having a light incident end surface of an area larger than the product, a.

  The method for producing a light diffusing member of the present invention is characterized in that any one of a black resin, black ink, a single metal, or a multilayer film of a single metal and a metal oxide is used as the material of the light shielding layer.

  The display device of the present invention is provided with a display body and a viewing angle widening member that is provided on the viewing side of the display body and emits light in a state where the angular distribution of light incident from the display body is wider than before incidence. The viewing angle enlarging member is composed of the light diffusing member of the present invention.

  In the display device of the present invention, the display body includes a plurality of pixels that form a display image, and the maximum pitch between adjacent light diffusion portions among the plurality of light diffusion portions of the light diffusion member is The pitch is smaller than the pitch between the pixels of the display body.

  In the display device of the present invention, the display body includes a light source and a light modulation element that modulates light from the light source, and the light source emits light having directivity.

  In the display device of the present invention, an adhesive layer is provided between the display body and the light diffusing member, and the adhesive layer has light diffusibility.

  In the display device of the present invention, the display body is a liquid crystal display element.

  ADVANTAGE OF THE INVENTION According to this invention, the light-diffusion member which can obtain desired light-diffusion performance, and its manufacturing method can be provided, without making a manufacturing process complicated. According to the present invention, it is possible to provide a display device that includes the light diffusing member and is excellent in display quality.

It is a perspective view which shows the liquid crystal display device of 1st Embodiment of this invention. 2 is a cross-sectional view of the liquid crystal display device. FIG. It is sectional drawing which shows the liquid crystal panel in a liquid crystal display device equally. It is a schematic diagram for demonstrating an effect | action of a viewing angle expansion film. It is a perspective view which shows the viewing angle expansion film of a liquid crystal display device later on in order of a manufacturing process. It is a schematic diagram which shows the 1st modification of a viewing angle expansion film equally. It is a schematic diagram which shows the 2nd modification of a viewing angle expansion film equally. It is a perspective view which shows the liquid crystal display device of 2nd Embodiment of this invention. 2 is a cross-sectional view of the liquid crystal display device. FIG. It is a perspective view which shows the viewing angle expansion film of a liquid crystal display device later on in order of a manufacturing process. It is a schematic diagram which shows the 1st modification of a viewing angle expansion film equally. It is a perspective view which shows the liquid crystal display device of 3rd Embodiment of this invention. 2 is a cross-sectional view of the liquid crystal display device. FIG. It is a schematic diagram for demonstrating an effect | action of a viewing angle expansion film. It is a perspective view which shows the viewing angle expansion film of a liquid crystal display device later on in order of a manufacturing process. It is a top view which shows the 1st modification of a viewing angle expansion film equally. It is a schematic diagram for demonstrating an effect | action of a viewing angle expansion film. It is a schematic diagram which shows the 2nd modification of a viewing angle expansion film equally. It is a perspective view which shows the liquid crystal display device of 4th Embodiment of this invention. It is a perspective view which shows the viewing angle expansion film of a liquid crystal display device later on in order of a manufacturing process. It is a perspective view which shows the liquid crystal display device of 5th Embodiment of this invention. It is a schematic diagram for demonstrating an effect | action of a viewing angle expansion film. It is a perspective view which shows the viewing angle expansion film of a liquid crystal display device later on in order of a manufacturing process. It is a perspective view which shows the liquid crystal display device of 6th Embodiment of this invention. It is a schematic diagram for demonstrating an effect | action of a viewing angle expansion film. It is a perspective view which shows the viewing angle expansion film of a liquid crystal display device later on in order of a manufacturing process. It is a top view which shows the other example of the light shielding layer in a viewing angle expansion film equally. It is a schematic diagram which shows the 1st modification of a viewing angle expansion film equally. It is a perspective view which shows the liquid crystal display device of 7th Embodiment of this invention. It is a perspective view which shows the viewing angle expansion film of a liquid crystal display device later on in order of a manufacturing process. It is a perspective view which shows the liquid crystal display device of 8th Embodiment of this invention. It is a perspective view which shows the viewing angle expansion film of a liquid crystal display device later on in order of a manufacturing process. It is sectional drawing which shows the liquid crystal display device of 9th Embodiment of this invention. It is a schematic diagram for demonstrating the effect | action of a scattering layer. It is sectional drawing which shows the liquid crystal display device of 10th Embodiment of this invention. It is a schematic diagram for demonstrating the effect | action of a scattering layer. It is a perspective view which shows an example of the manufacturing apparatus of a viewing angle expansion film. It is a perspective view which shows the principal part of the manufacturing apparatus of a viewing angle expansion film. It is a figure which shows the luminance angle characteristic of a directional backlight.

[First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, an example of a liquid crystal display device including a transmissive liquid crystal panel as a display body will be described.
In all of the following drawings, in order to make each component easy to see, the scale of the size may be changed depending on the component.

FIG. 1 is a perspective view of the liquid crystal display device of the present embodiment as viewed obliquely from below (back side).
FIG. 2 is a cross-sectional view of the liquid crystal display device of this embodiment.
As shown in FIGS. 1 and 2, the liquid crystal display device 1 (display device) of the present embodiment includes a backlight 2 (light source), a first polarizing plate 3, a liquid crystal panel 4 (light modulation element), and a second polarizing plate. The liquid crystal display body 6 (display body) which has 5 and the viewing angle expansion film 7 (viewing angle expansion member, a light-diffusion member) are comprised. In FIG. 2, the liquid crystal panel 4 is schematically illustrated as a single plate, but the detailed structure thereof will be described later. The observer sees the display from the upper side of the liquid crystal display device 1 in FIG. 2 where the viewing angle widening film 7 is arranged. Therefore, in the following description, the side on which the viewing angle widening film 7 is disposed is referred to as a viewing side, and the side on which the backlight 2 is disposed is referred to as a back side.

  In the liquid crystal display device 1 of the present embodiment, the light emitted from the backlight 2 is modulated by the liquid crystal panel 4, and a predetermined image, character, or the like is displayed by the modulated light. Further, when the light emitted from the liquid crystal panel 4 passes through the viewing angle widening film 7, the angle distribution of the emitted light becomes wider than before entering the viewing angle widening film 7, and the light is widened. Is injected from. Thereby, the observer can visually recognize the display with a wide viewing angle.

Hereinafter, a specific configuration of the liquid crystal panel 4 will be described.
Here, an active matrix transmissive liquid crystal panel is described as an example, but a liquid crystal panel applicable to the present invention is not limited to an active matrix transmissive liquid crystal panel. The liquid crystal panel applicable to the present invention may be, for example, a transflective (transmissive / reflective) liquid crystal panel or a reflective liquid crystal panel. Further, each pixel is a switching thin film transistor (Thin Film Transistor, hereinafter). It may be a simple matrix type liquid crystal panel not provided with (abbreviated as TFT).

FIG. 3 is a longitudinal sectional view of the liquid crystal panel 4.
As shown in FIG. 3, the liquid crystal panel 4 includes a TFT substrate 9 as a switching element substrate, a color filter substrate 10 disposed so as to face the TFT substrate 9, and the TFT substrate 9 and the color filter substrate 10. And a sandwiched liquid crystal layer 11. The liquid crystal layer 11 is surrounded by a TFT substrate 9, a color filter substrate 10, and a frame-shaped seal member (not shown) that bonds the TFT substrate 9 and the color filter substrate 10 at a predetermined interval. It is enclosed in the space.

  The liquid crystal panel 4 of this embodiment performs display in, for example, a VA (Vertical Alignment) mode, and the liquid crystal layer 11 uses vertical alignment liquid crystal having negative dielectric anisotropy. A spherical spacer 12 is disposed between the TFT substrate 9 and the color filter substrate 10 to keep the distance between these substrates constant. The display mode is not limited to the VA mode described above, and a TN (Twisted Nematic) mode, an STN (Super Twisted Nematic) mode, an IPS (In-Plane Switching) mode, or the like can be used.

  On the TFT substrate 9, a plurality of pixels (not shown) as a minimum unit region for display are arranged in a matrix. A plurality of source bus lines (not shown) are formed on the TFT substrate 9 so as to extend in parallel with each other, and a plurality of gate bus lines (not shown) extend in parallel with each other, And it is formed so as to be orthogonal to a plurality of source bus lines. Therefore, on the TFT substrate 9, a plurality of source bus lines and a plurality of gate bus lines are formed in a lattice pattern, and a rectangular region partitioned by adjacent source bus lines and adjacent gate bus lines is one. One pixel. The source bus line is connected to the source electrode of the TFT described later, and the gate bus line is connected to the gate electrode of the TFT.

  A TFT 19 having a semiconductor layer 15, a gate electrode 16, a source electrode 17, a drain electrode 18, etc. is formed on the surface of the transparent substrate 14 constituting the TFT substrate 9 on the liquid crystal layer 11 side. As the transparent substrate 14, for example, a glass substrate can be used. On the transparent substrate 14, for example, a semiconductor material such as CGS (Continuous Grain Silicon), LPS (Low-temperature Poly-Silicon), α-Si (Amorphous Silicon), etc. A semiconductor layer 15 made of is formed.

  A gate insulating film 20 is formed on the transparent substrate 14 so as to cover the semiconductor layer 15. As a material of the gate insulating film 20, for example, a silicon oxide film, a silicon nitride film, or a laminated film thereof can be used. A gate electrode 16 is formed on the gate insulating film 20 so as to face the semiconductor layer 15. As the material of the gate electrode 16, for example, a laminated film of W (tungsten) / TaN (tantalum nitride), Mo (molybdenum), Ti (titanium), Al (aluminum), or the like is used.

  A first interlayer insulating film 21 is formed on the gate insulating film 20 so as to cover the gate electrode 16. As a material of the first interlayer insulating film 21, for example, a silicon oxide film, a silicon nitride film, or a laminated film thereof can be used.

  A source electrode 17 and a drain electrode 18 are formed on the first interlayer insulating film 21. The source electrode 17 is connected to the source region of the semiconductor layer 15 through a contact hole 22 that penetrates the first interlayer insulating film 21 and the gate insulating film 20. Similarly, the drain electrode 18 is connected to the drain region of the semiconductor layer 15 through a contact hole 23 that penetrates the first interlayer insulating film 21 and the gate insulating film 20. As a material for the source electrode 17 and the drain electrode 18, the same conductive material as that for the gate electrode 16 described above can be used. A second interlayer insulating film 24 is formed on the first interlayer insulating film 21 so as to cover the source electrode 17 and the drain electrode 18. As the material of the second interlayer insulating film 24, the same material as the first interlayer insulating film 21 described above or an organic insulating material can be used.

  A pixel electrode 25 is formed on the second interlayer insulating film 24. The pixel electrode 25 is connected to the drain electrode 18 through a contact hole 26 that penetrates the second interlayer insulating film 24. Therefore, the pixel electrode 25 is connected to the drain region of the semiconductor layer 15 using the drain electrode 18 as a relay electrode. As the material of the pixel electrode 25, for example, a transparent conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) can be used. With this configuration, when the scanning signal is supplied through the gate bus line and the TFT 19 is turned on, the image signal supplied to the source electrode 17 through the source bus line passes through the semiconductor layer 15 and the drain electrode 18 to form a pixel electrode. 25. An alignment film 27 is formed on the entire surface of the second interlayer insulating film 24 so as to cover the pixel electrode 25. This alignment film 27 has an alignment regulating force for vertically aligning liquid crystal molecules constituting the liquid crystal layer 11. Note that the form of the TFT may be the bottom gate TFT shown in FIG. 3 or the top gate TFT.

  On the other hand, a black matrix 30, a color filter 31, a planarization layer 32, a counter electrode 33, and an alignment film 34 are sequentially formed on the surface of the transparent substrate 29 constituting the color filter substrate 10 on the liquid crystal layer 11 side. The black matrix 30 has a function of blocking light transmission in the inter-pixel region. The black matrix 30 is formed of, for example, a metal such as Cr (chromium) or a Cr / Cr oxide multilayer film, or a photoresist in which carbon particles are dispersed in a photosensitive resin.

  The color filter 31 includes dyes of red (R), green (G), and blue (B) colors. One pixel electrode 25 on the TFT substrate 9 is provided with any one of R, G, and B color filters 31 facing each other. Note that the color filter 31 may have a multicolor configuration of three or more colors of R, G, and B.

  The planarization layer 32 is composed of an insulating film that covers the black matrix 30 and the color filter 31. The planarizing layer 32 has a function of smoothing and leveling a step formed by the black matrix 30 and the color filter 31. A counter electrode 33 is formed on the planarization layer 32. As the material of the counter electrode 33, a transparent conductive material similar to that of the pixel electrode 25 is used. In addition, an alignment film 34 having a vertical alignment regulating force is formed on the entire surface of the counter electrode 33.

  Returning to FIG. 2, the backlight 2 includes a light source 36 such as a light emitting diode and a cold cathode tube, and a light guide plate 37 that emits light toward the liquid crystal panel 4 using internal reflection of light emitted from the light source 36. Have. The backlight 2 may be an edge light type in which the light source is disposed on the end face of the light guide, or may be a direct type in which the light source is disposed directly under the light guide. As the backlight 2 used in the present embodiment, it is desirable to use a backlight having a directivity by controlling the light emission direction, that is, a so-called directional backlight. By using a directional backlight that allows collimated or substantially collimated light to enter the light diffusion portion of the viewing angle widening film 7 to be described later, blurring can be reduced and light utilization efficiency can be increased. The directional backlight described above can be realized by optimizing the shape and arrangement of the reflection pattern formed in the light guide plate 37. Alternatively, directivity may be realized by installing a louver on the backlight. A first polarizing plate 3 that functions as a polarizer is provided between the backlight 2 and the liquid crystal panel 4. A second polarizing plate 5 that functions as a polarizer is provided between the liquid crystal panel 4 and the viewing angle widening film 7.

Hereinafter, the viewing angle widening film 7 will be described in detail.
FIG. 4A is a cross-sectional view of the viewing angle widening film 7.
As shown in FIGS. 1, 2, and 4 (A), the viewing angle widening film 7 includes a base material 39 and a plurality of lights formed on one surface of the base material 39 (a surface opposite to the viewing side). The diffusion unit 40 and a light shielding layer 41 formed on one surface of the base material 39 are included. As shown in FIG. 2, the viewing angle widening film 7 has a posture in which the side where the light diffusing portion 40 is provided faces the second polarizing plate 5 and the base 39 side faces the viewing side. 5 is fixed on the adhesive layer 8. Adhesive layer materials include rubber-based, acrylic-based, silicone-based, vinyl alkyl ether-based, polyvinyl alcohol-based, polyvinyl pyrrolidone-based, polyacrylamide-based, and cellulose-based adhesives, etc. Substances can be used. In particular, an adhesive substance excellent in transparency and weather resistance is preferably used. The adhesive layer is preferably protected by temporarily attaching a separator or the like until practical use.

In the following description, the horizontal direction of the screen of the liquid crystal panel 4 is defined as the x axis, the vertical direction of the screen of the liquid crystal panel 4 is defined as the y axis, and the thickness direction of the liquid crystal display device 1 is defined as the z axis.
The light diffusion portion 40 is formed so as to extend in the vertical direction (y-axis direction) of the screen of the liquid crystal panel 4. The light diffusing portion 40 has a rectangular shape with a horizontal cross section (xy cross section), a surface 40a on the base material 39 side serving as a light emission end surface is small, and a surface opposite to the base material 39 serving as a light incident end surface. The area of 40b is formed large. The plurality of light diffusing portions 40 are arranged in stripes at regular intervals as viewed from the normal direction (z-axis direction) of the base material 39. The light shielding layer 41 is arranged in a stripe shape between the adjacent light diffusion portions 40 arranged in a stripe shape when viewed from the normal direction (z-axis direction) of the base material 39.

  As the base material 39, generally, a thermoplastic polymer, a thermosetting resin, a resin such as a photopolymerizable resin, or the like is used. Use an appropriate transparent resin substrate made of acrylic polymer, olefin polymer, vinyl polymer, cellulose polymer, amide polymer, fluorine polymer, urethane polymer, silicone polymer, imide polymer, etc. Can do. For example, triacetyl cellulose (TAC) film, polyethylene terephthalate (PET) film, cycloolefin polymer (COP) film, polycarbonate (PC) film, polyethylene naphthalate (PEN) film, polyethersulfone (PES) film, polyimide ( PI) A transparent resin base material such as a film is preferably used. The base material 39 serves as a base when a material for the light shielding layer 41 and the light diffusion portion 40 is applied later in the manufacturing process described later, and has heat resistance and mechanical strength in the heat treatment step during the manufacturing process. It is necessary to prepare. Therefore, as the base material 39, a glass base material or the like may be used in addition to the resin base material. However, it is preferable that the thickness of the base material 39 is as thin as possible without impairing heat resistance and mechanical strength. The reason is that as the thickness of the base material 39 is increased, there is a possibility that display blur may occur. Further, the total light transmittance of the base material 39 is preferably 90% or more as defined in JIS K7361-1. When the total light transmittance is 90% or more, sufficient transparency can be obtained. In this embodiment, a TAC film having a thickness of 100 μm is used as an example.

  The light diffusion portion 40 includes a layer made of a first material (first layer 42) and a layer made of a second material that is incompatible with the first material (second layer 43). It is out. In general, a mixture of different types of polymer materials is incompatible. For example, the light diffusion unit 40 can use an acrylic resin as the first material, and can use an epoxy resin as the second material. The light diffusing unit 40 is made of an organic material having light transparency and photosensitivity. Further, the total light transmittance of the light diffusing unit 40 is preferably 90% or more in accordance with JIS K7361-1. When the total light transmittance is 90% or more, sufficient transparency can be obtained. As shown in FIGS. 1, 2, and 4 (A), the light diffusion portion 40 is composed of two layers, a first layer 42 and a second layer 43, which are laminated in this order from the base material 39 side. . In the present embodiment, the first layer 42 is formed of an acrylic resin-based transparent negative resist, and the second layer 43 is formed of an epoxy resin-based transparent negative resist. As a material for the light diffusion portion, a transparent resin mixture in which a polymerization initiator, a coupling agent, a monomer, an organic solvent, and the like are mixed with a resin such as an acrylic resin, an epoxy resin, or a silicone resin can be used. The polymerization initiator may contain various additional components such as stabilizers, inhibitors, plasticizers, optical brighteners, mold release agents, chain transfer agents, other photopolymerizable monomers, and the like. In addition, materials described in Japanese Patent No. 4129991 can be used.

  As shown in FIG. 4A, the light diffusing unit 40 has a small area of the surface 40a on the base material 39 side as a light emission end face, and the area of the horizontal cross section gradually increases as the distance from the base material 39 increases. Is getting bigger. That is, when viewed from the base material 39 side, the light diffusing portion 40 has a so-called reverse tapered substantially quadrangular pyramid shape. The inversely tapered side surface 40 c of the light diffusing portion 40 is composed of a side surface 42 c of the first layer 42 and a side surface 43 c of the second layer 43. The interface 40d between the first layer 42 and the second layer 43 is formed in parallel with the light incident end face 40b and the light exit end face 40a of the light diffusion portion 40. The width W1 (dimension in the short direction) of the light incident end face 40b of the light diffusion portion 40 is, for example, 10 μm, and the pitch P1 between the adjacent light diffusion portions 40 is 20 μm.

  An angle θ2 formed between the side surface 43c of the second layer 43 and the light incident end surface 40b is larger than an angle θ1 formed between the side surface 42c of the first layer 42 and the interface 40d. In the following description, an angle θ2 formed between the side surface 43c of the second layer 43 and the light incident end surface 40b is referred to as an inclination angle of the side surface 43c of the second layer 43, and an angle formed between the side surface 42c of the first layer 42 and the interface 40d. θ1 is referred to as an inclination angle of the side surface 42c of the first layer 42. The inclination angle θ1 of the side surface 42c of the first layer 42 and the inclination angle θ2 of the side surface 43c of the second layer 43 are preferably 60 ° or more and less than 90 °.

  The inclination angles of the plurality of side surfaces of the light diffusing portion 40 (inclination angle θ1 of the side surface 42c of the first layer 42 and inclination angle θ2 of the side surface 43c of the second layer 43) increase as it approaches the light incident end surface 40b side. Yes. For example, the inclination angle θ1 of the side surface 42c of the first layer 42 is 75 degrees, and the inclination angle θ2 of the side surface 43c of the second layer 43 is 80 degrees. However, the inclination angle θ1 of the side surface 42c of the first layer 42 and the inclination angle θ2 of the side surface 43c of the second layer 43 are angles that can sufficiently diffuse the incident light without causing a large loss of incident light. If there is, it will not be specifically limited.

  The light diffusion part 40 is a part that contributes to the transmission of light in the viewing angle widening film 7. That is, as shown in FIG. 4A, the light incident on the light diffusing unit 40 is totally reflected by the tapered side surface 40c of the light diffusing unit 40 and is substantially confined inside the light diffusing unit 40. The light is guided and ejected.

  As shown in FIGS. 1, 2, and 4 (A), the light shielding layer 41 is a region other than a region where the light diffusing portions 40 are formed on the surface of the base 39 on which the light diffusing portions 40 are formed. It is formed in the area. For example, the light shielding layer 41 is made of an organic material having light absorption and photosensitivity such as a black resist. In addition to this, the light shielding layer 41 is a black ink obtained by mixing a metal film such as a multilayer film of Cr (chromium) or Cr / Cr oxide, a pigment / dye used for black ink, and a multicolor ink. May be used. Other than these materials, any material having a light shielding property may be used. The width (dimension in the short direction) of the light shielding layer 41 is, for example, 10 μm.

  The thickness of the light shielding layer 41 is set to be smaller than the height from the light incident end surface 40b of the light diffusion portion 40 to the light emitting end surface 40a. In the present embodiment, the thickness of the light shielding layer 41 is about 150 nm as an example, and the height from the light incident end face 40b to the light emitting end face 40a of the light diffusing portion 40 is about 50 μm as an example. In the gap between the plurality of light diffusing portions 40, the light shielding layer 41 exists in a portion in contact with one surface of the base material 39, and air exists in other portions.

  It is desirable that the refractive index of the first layer 42 and the refractive index of the second layer 43 are substantially equal. The reason is that, for example, if the refractive index of the first layer 42 and the refractive index of the second layer 43 are significantly different, the interface 40d is transmitted when light passes through the interface 40d between the first layer 42 and the second layer 43. This is because unnecessary refraction and reflection of light may occur, resulting in problems such as failure to obtain a desired light diffusion angle and reduction in the amount of emitted light. For the same reason, it is desirable that the refractive index of the base material 39 and the refractive index of the first layer 42 be substantially equal.

  Basically, the inclination angle of the side surface 40c of the light diffusing unit 40 is such that the light incident on the light incident end surface 40b of the light diffusing unit 40 is totally or substantially perpendicularly reflected so that the side surface 40c of the light diffusing unit 40 is totally reflected. It is set to an angle exceeding the critical angle with respect to the normal line.

  By the way, as shown in FIG. 4B, in the case of the viewing angle widening film 107 in which the inclination angle θ3 of the side surface 140c of the light diffusing portion 140 is constant, it is incident perpendicularly to the light incident end surface 140b of the light diffusing portion 140. The light L1 to be reflected is totally reflected by the side surface 140c of the light diffusion portion 140. However, the light L2 incident at an angle other than 90 degrees with respect to the light incident end face 140b of the light diffusing unit 140 has an incident angle smaller than the critical angle, and is transmitted through the side surface 140c of the light diffusing unit 140 to emit light. There is a possibility that it cannot be taken out from the end face 140a. Further, when the inclination angle of the side surface 140c of the light diffusing unit 140 is constant, the light L1 incident perpendicularly to the light incident end surface 140b of the light diffusing unit 140 is emitted in a concentrated manner at a specific diffusion angle. As a result, light cannot be uniformly diffused over a wide angle range, and a bright display can be obtained only with a specific viewing angle.

  On the other hand, in the viewing angle widening film 7 of the present embodiment, as shown in FIG. 4A, the side surface 40c of the light diffusion portion 40 has two different inclination angles θ1 and θ2. The inclination angle θ2 of the side surface 43c of the second layer 43 is larger than the inclination angle θ1 of the side surface 42c of the first layer 42. Thereby, the light L0 incident perpendicularly to the light incident end surface 40b in the central portion of the light diffusing portion 40 is transmitted through the light diffusing portion 40 without being incident on the side surface 40c.

  On the other hand, the light L1 incident perpendicularly to the light incident end face 40b at the peripheral edge of the light diffusing portion 40 is totally reflected by the side surface 43c of the second layer 43, for example, and then the angle is changed to change the first layer 42 and the base material. 39 is sequentially transmitted and injected to the outside. The light L2 incident at an angle other than 90 degrees with respect to the light incident end surface 40b of the light diffusing unit 40 is totally reflected at, for example, the side surface 42c of the first layer 42, and then the angle is changed to change the first layer 42 and the base material 39. Are sequentially transmitted and injected to the outside.

  Thus, in the case of this embodiment, since the side surface 40c of the light-diffusion part 40 has two different inclination angles, it is possible to prevent the light diffusion angles from being concentrated on one. As a result, the light diffusion characteristics of the viewing angle widening film 7 can be made smoother, and a bright display can be obtained with a wide viewing angle.

  In the case of the present embodiment, since air is interposed between the adjacent light diffusion portions 40, if the light diffusion portion 40 is formed of, for example, acrylic resin, the side surface 40c of the light diffusion portion 40 is made of acrylic resin and air. It becomes the interface. Even if the periphery of the light diffusing unit 40 is filled with another low refractive index material, the difference in the refractive index between the inside and the outside of the light diffusing unit 40 is larger than when any low refractive index material exists outside. The maximum is when air is present. Therefore, from Snell's law, in the configuration of the present embodiment, the critical angle is the smallest, and the incident angle range in which light is totally reflected by the side surface 40c of the light diffusing unit 40 is the widest. As a result, light loss is further suppressed, and high luminance can be obtained.

  However, as shown in FIG. 4A, the light L3 incident at an angle greatly shifted from 90 degrees with respect to the light incident end face 40b of the light diffusing portion 40 is a critical angle with respect to the side surface 40c of the light diffusing portion 40. The light is incident at the following angle and passes through the side surface 40c of the light diffusing unit 40 without being totally reflected. Still, since the light shielding layer 41 is provided in a region other than the region where the light diffusion portion 40 is formed, the light transmitted through the side surface 40 c of the light diffusion portion 40 is absorbed by the light shielding layer 41. Therefore, there is no blurring of display and no reduction in contrast. However, when the amount of light transmitted through the side surface 40c of the light diffusing unit 40 increases, a light amount loss occurs, and an image with high luminance cannot be obtained. Therefore, in the liquid crystal display device 1 of the present embodiment, it is preferable to use a backlight that emits light at an angle that does not enter the side surface 40c of the light diffusing portion 40 at a critical angle or less, that is, a so-called directional backlight. .

FIG. 39A shows luminance angle characteristics of a directional backlight. In this figure, regarding the light emitted from the directional backlight, the horizontal axis indicates the emission angle (°), and the vertical axis indicates the luminance (cd / m ² ). In the directional backlight used this time, it can be seen that almost all the emitted light falls within an emission angle of ± 30 °. By combining this directional backlight and a viewing angle widening film, it is possible to realize a configuration with less blur and high light utilization efficiency.

As shown in FIG. : Output angle from backlight, θb : It is defined as the taper angle of the light diffusing unit 40. The light La incident on the light diffusing unit 40 undergoes total reflection at the taper portion and is emitted from the surface of the base material 39 to the viewer side. However, the light Lb having a large incident angle is transmitted through the taper portion without being totally reflected. Light loss may occur.

  FIG. 39C shows the relationship between the emission angle from the backlight and the taper angle as the critical angle. For example, light having an emission angle of 30 ° from the backlight is transmitted without being totally reflected in a tapered shape when the light diffusion portion 40 with a transparent resin refractive index n = 1.6 has a taper angle of less than 57 °, and light loss Occurs. In order to totally reflect light within an emission angle of ± 30 ° without loss, the taper angle of the light diffusion portion 40 is desirably 57 ° or more and less than 90 °.

Next, a manufacturing method of the liquid crystal display device 1 having the above configuration will be described with reference to FIG.
Below, it demonstrates centering on the manufacturing process of the viewing angle expansion film 7. FIG.
The outline of the manufacturing process of the liquid crystal display 6 will be described first. First, the TFT substrate 9 and the color filter substrate 10 are respectively produced. Thereafter, the surface of the TFT substrate 9 on which the TFT 19 is formed and the surface of the color filter substrate 10 on which the color filter 31 is formed are arranged to face each other, and the TFT substrate 9 and the color filter substrate 10 are sealed. Paste through. Thereafter, liquid crystal is injected into a space surrounded by the TFT substrate 9, the color filter substrate 10, and the seal member. And the 1st polarizing plate 3 and the 2nd polarizing plate 5 are each bonded together on both surfaces of the liquid crystal panel 4 produced in this way using an optical adhesive agent. Through the above steps, the liquid crystal display body 6 is completed.
In addition, since a conventionally well-known method is used for the manufacturing method of the TFT substrate 9 and the color filter substrate 10, description is abbreviate | omitted.

First, as shown in FIG. 5A, a 10-cm square triacetyl cellulose base material 39 having a thickness of 100 μm is prepared, and a spin coat method is used as a light shielding layer material on one surface of the base material 39. A black negative resist containing carbon is applied to form a coating film 44 having a thickness of 150 nm.
Next, the base material 39 on which the coating film 44 is formed is placed on a hot plate, and the coating film is pre-baked at a temperature of 90 ° C. Thereby, the solvent in the black negative resist is volatilized.

Next, using an exposure apparatus, as shown in FIG. 5B, the coating film 44 is irradiated with light E through a photomask 45 provided with a plurality of light shielding patterns 47 to perform exposure. At this time, an exposure apparatus using a mixed line of i-line having a wavelength of 365 nm, h-line having a wavelength of 404 nm, and g-line having a wavelength of 436 nm is used. The exposure dose is 100 mJ / cm ² . In the case of this embodiment, in the next step, the transparent negative resist is exposed using the light shielding layer 41 as a mask to form the light diffusing portion 40, so that the position of the opening 46 of the photomask 45 is the position where the light diffusing portion 40 is formed. Correspond. The plurality of light shielding patterns 47 are band-like patterns having a width of 10 μm, and are arranged at a pitch of 20 μm.

  The pitch of the light shielding patterns 47 is desirably smaller than the interval (pitch) of the pixels of the liquid crystal panel 4. As a result, at least one light diffusing portion 40 is formed in the pixel, so that a wide viewing angle can be achieved when combined with a liquid crystal panel having a small pixel pitch used for mobile devices, for example.

  After performing exposure using the photomask 45 described above, the coating film 44 made of a black negative resist is developed using a dedicated developer, dried at 100 ° C., and as shown in FIG. A plurality of strip-shaped light shielding layers 41 are formed on one surface of the base material 39. The opening between the adjacent light shielding layers 41 corresponds to the formation region of the light diffusion portion 40 in the next process.

  In the present embodiment, the light shielding layer 41 is formed by a photolithography method using a black negative resist. Instead of this configuration, a photomask in which the light shielding pattern 47 and the opening 46 of the present embodiment are reversed is used. For example, a positive resist can be used. Or you may form directly the light shielding layer 41 patterned using the vapor deposition method, the printing method, etc. FIG.

  Next, a negative photosensitive resin material in which a plurality of materials that are incompatible with each other is mixed is prepared. The negative photosensitive resin material is a material that forms a phase separation structure from a mixed liquid phase. For example, the negative photosensitive resin material is a mixture of a transparent negative resist made of acrylic resin as the first material and a transparent negative resist made of epoxy resin as the second material. The light diffusing portion 40 does not have to be formed of two layers, and may be formed of a multilayered phase separation structure of three or more layers by mixing a plurality of incompatible materials.

  Next, as shown in FIG. 5D, a negative photosensitive resin material is applied to the upper surface of the light shielding layer 41 using a spin coating method to form a coating film 48 having a thickness of 50 μm. Next, the base material 39 on which the coating film 48 is formed is placed on a hot plate, and the coating film 48 is pre-baked at a temperature of 95 ° C. Thereby, while evaporating the solvent, the negative photosensitive resin material is phase-separated, and a plurality of negative photosensitive resin layers (the coating film 49 made of acrylic resin and the epoxy resin separated in the normal direction of one surface of the base material 39) are separated. A coating film 50) made of resin is formed. In this way, the two-layer coating films 49 and 50 made of different types of transparent negative resists are formed. For example, the film thickness of the coating film 49 is about 25 μm, and the film thickness of the coating film 50 is about 25 μm.

Next, as shown in FIG. 5E, the coating films 49 and 50 are irradiated with diffused light F from the substrate 39 side using the light shielding layer 41 as a mask to perform exposure. At this time, an exposure apparatus using a mixed line of i-line having a wavelength of 365 nm, h-line having a wavelength of 404 nm, and g-line having a wavelength of 436 nm is used. The exposure amount is 500 mJ / cm ² . In the exposure process, parallel light or diffused light is used. Further, as means for irradiating the base material 39 with the parallel light emitted from the exposure apparatus as diffused light F, a diffusion plate having a haze of about 50 is disposed on the optical path of the light emitted from the exposure apparatus. By performing exposure with the diffused light F, the two-layered coating films 49 and 50 are exposed radially from the opening between the light shielding layers 41, and the reverse tapered side surface of the light diffusing unit 40 is formed.
Thereafter, the base material 39 after the exposure process is placed on a hot plate, and post-exposure baking (PEB) of the coating films 49 and 50 is performed at a temperature of 95 ° C.

Next, the coating films 49 and 50 made of a transparent negative resist are developed using a dedicated developer, post-baked at 100 ° C., and the first layer 42 and the second layer 43 as shown in FIG. A plurality of light diffusing portions 40 are formed on one surface of the base material 39.
Through the above steps, the viewing angle widening film 7 of the present embodiment is completed. The total light transmittance of the viewing angle widening film 7 is preferably 90% or more. When the total light transmittance is 90% or more, sufficient transparency can be obtained, and the optical performance required for the viewing angle widening film can be sufficiently exhibited. The total light transmittance is in accordance with JIS K7361-1.

  In the above example, the liquid resist is applied at the time of forming the light shielding layer 41 and the light diffusing portion 40, but instead of this configuration, a film resist is applied to one surface of the base material 39. Also good.

Finally, as shown in FIG. 2, the completed viewing angle widening film 7 is placed with the base material 39 facing the viewing side and the light diffusion portion 40 facing the second polarizing plate 5 with the adhesive layer 8 interposed therebetween. Is attached to the liquid crystal display body 6.
Through the above steps, the liquid crystal display device 1 of the present embodiment is completed.

  If exposure is performed using one type of transparent negative resist as a material for the light diffusion portion, the side surface of the light diffusion portion has a single inclination angle. On the other hand, in this embodiment, when forming the light-diffusion part 40, it exposes by forming the coating films 49 and 50 of the two-layer structure which consist of a different kind of transparent negative resist. In this case, the photosensitive part of the transparent negative resist after the exposure process has a single inclination angle over the two layers. However, since the photocuring characteristics of the respective transparent negative resists are different, the photosensitive portions of the coating films 49 and 50 are cured into different shapes. As a result, in the state where the light diffusion portion 40 is completed after development, the inclination angle of the side surface 42c of the first layer 42 and the inclination angle of the side surface 43c of the second layer 43 are different.

  According to this embodiment, as shown in FIG. 4 (A), the light L0, L1, L2 incident on the viewing angle widening film 7 has a wider angular distribution than before entering the viewing angle widening film 7. Is emitted from the viewing angle widening film 7. Therefore, even if the observer inclines the line of sight from the front direction (normal direction) of the liquid crystal display body 6, a good display can be visually recognized. In particular, in the case of the present embodiment, since the light diffusion portion 40 extends in a stripe shape in the vertical direction of the screen, the angular distribution spreads in the horizontal direction (left-right direction) of the screen of the liquid crystal display body 6. Therefore, the observer can visually recognize a good display in a wide range in the left-right direction of the screen.

  On the other hand, the light L3 obliquely incident on the viewing angle widening film 7 is light that is obliquely transmitted through the liquid crystal panel 4, and is light that is different from a desired retardation, that is, light that causes a decrease in so-called display contrast. . The viewing angle widening film 7 of this embodiment can increase the display contrast because such light is cut by the light shielding layer 41. Furthermore, since the external light incident on the viewing angle expansion film 7 from the viewing side is also cut by the light shielding layer 41, the scattering of the external light is suppressed, and the visibility of display in a bright place can be improved.

  In the present embodiment, since the light diffusion portion 40 is formed using the two-layered coating films 49 and 50 made of different types of transparent negative resists, the side surface 40c has two types of inclination angles θ1 and θ2. The plurality of light diffusion portions 40 can be easily formed by a single photolithography process. Therefore, the viewing angle widening film 7 that can exhibit the desired light diffusion performance can be produced without complicating the manufacturing process.

  Further, in the step of forming the light diffusion portion 40, assuming that exposure is performed using a photomask from the side of the coating film 49, 50 made of a transparent negative resist, the substrate 39 on which the light shielding layer 41 having a minute size is formed and the photo Alignment with the mask is very difficult, and it is inevitable that a deviation occurs. On the other hand, in the case of the present embodiment, since light is irradiated from the back side of the base material 39 using the light shielding layer 41 as a mask, the light diffusion portion 40 is self-aligned with the position of the opening of the light shielding layer 41 (self It is formed in an aligned state. As a result, the light diffusion portion 40 and the light shielding layer 41 are in close contact with each other, so that no gap is formed between them, and the contrast can be reliably maintained.

[First Modification of First Embodiment]
FIG. 6 is a schematic view showing a first modification of the viewing angle widening film of the above embodiment. FIG. 6A is a perspective view of the viewing angle widening film 7A of this modification, and FIG. 6B is a cross-sectional view of the viewing angle widening film 7A of this modification.
In the above embodiment, the plurality of light diffusing portions 40 including the first layer 42 and the second layer 43 are independently formed on one surface of the base material 39. However, the viewing angles shown in FIGS. Like the magnifying film 7A, a plurality of light diffusion portions 40A composed of the first layer 42A and the second layer 43A may be connected at least in part. In the present modification, the second layer 43A is connected in two adjacent light diffusion sections 40A, and the two first layers 42A share one second layer 43A.

  According to this structure, each light-diffusion part 40A becomes difficult to fall down, and the form stability of the viewing angle expansion film 7A improves. In addition, when the second layer 43A is connected, the ratio of the light incident on the viewing angle widening film 7A being absorbed by the light shielding layer 41 is reduced, so that the light use efficiency is improved.

[Second Modification of First Embodiment]
FIG. 7A is a cross-sectional view showing a second modification of the viewing angle widening film of the above embodiment.
In the above embodiment, the interface 40d between the first layer 42 and the second layer 43 is formed in parallel with the light incident end surface 40b and the light emitting end surface 40a of the light diffusing section 40. However, the visual field shown in FIG. Like the corner expansion film 7B, the interface 40Bd between the first layer 42B and the second layer 43B may be formed non-parallel to the light incident end surface 40Bb and the light emitting end surface 40Ba of the light diffusion portion 40B. Furthermore, in this modification, the interface 40Bd between the first layer 42B and the second layer 43B is configured to include a curved surface. In the above embodiment, the refractive index of the first layer 42 and the refractive index of the second layer 43 are substantially equal. In this modification, the refractive index of the first layer 42B and the refractive index of the second layer 43B are used. The rate is different.

  By the way, as shown in FIG. 7B, the interface 140Bd between the first layer 142B and the second layer 143B is formed in parallel with the light incident end surface 140Bb and the light emitting end surface 140Ba of the light diffusion portion 140B, and When the refractive index of the first layer 142B is different from that of the second layer 143B, the lights L1 and L2 incident perpendicularly to the light incident end surface 140Bb of the light diffusion portion 140B are not refracted at the interface 140Bd. On the other hand, the light L3 incident at an angle other than 90 degrees with respect to the light incident end face 140Bb of the light diffusion portion 140B is refracted at the interface 140Bd.

  On the other hand, in the viewing angle widening film 7B of the present modification, as shown in FIG. 7A, the interface 40Bd between the first layer 42B and the second layer 43B is the light incident end face 40Bb of the light diffusion portion 40B and The light emitting end face 40Ba is formed non-parallel, and the refractive index of the first layer 42B is different from the refractive index of the second layer 43B. Thereby, the light L1 and L2 incident perpendicularly to the light incident end face 40Bb of the light diffusion portion 40B are refracted at the interface 40Bd. On the other hand, the light L3 incident at an angle other than 90 degrees with respect to the light incident end face 40Bb of the light diffusion portion 40 is also refracted at the interface 40Bd.

  Thus, in the case of this modification, since the interface 40Bd is not parallel to the light incident end face 40Bb and the light exit end face 40Ba of the light diffusing portion 40B, the light is perpendicular to the light incident end face 40Bb of the light diffusing portion 40B. Even if it is incident, the light can be refracted at the interface 40Bd of the light diffusion portion 40B. Thereby, the total reflection angle at the side surface 40Bc of the light refracted at the interface 40Bd of the light diffusion unit 40B and incident on the side surface 40Bc of the light diffusion unit 40B is not refracted at the interface 140Bd of the light diffusion unit 140B. It becomes larger than the total reflection angle at the side surface 140Bc of the light incident on the side surface 140Bc of 140B. For this reason, it is possible to prevent the diffusion angle of light incident perpendicularly to the light incident end face 40Bb of the light diffusion portion 40B from being concentrated at a specific diffusion angle. As a result, the light diffusion characteristics of the viewing angle widening film 7B can be made gentler, and a bright display can be obtained with a wide viewing angle.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the liquid crystal display device of this embodiment is the same as that of the first embodiment, and only the shape of the light diffusion portion of the viewing angle widening film is different from that of the first embodiment. Therefore, in this embodiment, description of the basic composition of a liquid crystal display device is abbreviate | omitted, and only a viewing angle expansion film is demonstrated.
FIG. 8 is a perspective view showing the liquid crystal display device of the present embodiment.
FIG. 9 is a cross-sectional view showing the liquid crystal display device of this embodiment.
10A to 10F are cross-sectional views showing the viewing angle widening film in order of the manufacturing process.
8, 9, and 10 </ b> A to 10 </ b> F, the same components as those used in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the first embodiment, the widths (dimensions in the short direction) of the plurality of light diffusion portions 40 are constant. On the other hand, in the viewing angle widening film 52 of this embodiment, as shown in FIGS. 8 and 9, the width (dimension in the short direction) of the light shielding layer 41 is constant, and the first layer 54, the second layer The widths (dimensions in the short direction) of the plurality of light diffusion portions 53 formed of the layer 55 are randomly different. That is, the width of the plurality of light diffusion portions 53 is not constant, and the average width obtained by averaging the widths of the plurality of light diffusion portions 53 is 10 μm. Further, the two inclination angles of the side surface 53c of the light diffusion portion 53 are uniform over the plurality of light diffusion portions 53, and are the same as those in the first embodiment. Other configurations are the same as those in the first embodiment.

  In the manufacturing process of the viewing angle widening film 52 of this embodiment, as shown in FIG. 10B, the photomask 56 used when forming the light shielding layer 41 is randomly different in width from the opening 57 having a constant width. The shading pattern 58 is provided. When designing the photomask 56, openings 57 having a constant width are first arranged at a constant pitch, and then each opening 57 such as the center point of the opening 57 is used by using a random function. By providing the reference position data with fluctuations and varying the positions of the openings 57, it is possible to obtain a plurality of light shielding patterns 58 having different widths at random. The manufacturing process itself of the viewing angle widening film 52 is the same as that of the first embodiment.

  In the liquid crystal display device 51 of the present embodiment as well, a first embodiment in which a viewing angle widening film capable of exhibiting desired light diffusion performance in the horizontal direction (left and right direction) of the screen can be produced without complicating the manufacturing process. The same effect as the form can be obtained.

  In general, it is known that when regular patterns such as stripes and lattices are superposed, an interference fringe pattern (moire) is visually recognized if the period of each pattern is slightly shifted. When the viewing angle widening film in which a plurality of light diffusion portions are arranged at a constant pitch and a liquid crystal panel in which a plurality of pixels are arranged at a constant pitch are overlapped as in the first embodiment, There is a possibility that moire occurs between the periodic pattern formed by the light diffusing unit and the periodic pattern formed by the pixels of the liquid crystal panel, thereby degrading the display quality. On the other hand, according to the liquid crystal display device 51 of the present embodiment, since the widths of the plurality of light diffusion portions 53 are random, moire due to interference occurs with the regular arrangement of the pixels of the liquid crystal panel 4. The display quality can be maintained.

[First Modification of Second Embodiment]
FIG. 11A is a perspective view showing a first modification of the viewing angle widening film of the above embodiment. FIG. 11B is a cross-sectional view showing a first modification of the viewing angle widening film.
In the above embodiment, the width of the light shielding layer 41 is constant. In addition to making the width of the light diffusion portion 53A random like the viewing angle widening film 52A shown in FIGS. 11A and 11B, The width of the light shielding layer 41A may be random.

Even in this configuration, an effect that moire is suppressed and display quality can be maintained is obtained.
However, when the inclination angles of the side surfaces of the plurality of light diffusion portions 53A are uniform and the width of the light shielding layer 41 is random, the ratio of the light incident on the viewing angle widening film 52A absorbed by the light shielding layer 41A As a result, the light utilization efficiency may be slightly reduced. From this viewpoint, it is preferable that the width of the light shielding layer is constant.

[Third embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the liquid crystal display device of the present embodiment is the same as that of the first and second embodiments, and only the shape of the light diffusion portion of the viewing angle widening film is different from that of the first and second embodiments. Therefore, in this embodiment, description of the basic composition of a liquid crystal display device is abbreviate | omitted, and only a viewing angle expansion film is demonstrated.
FIG. 12 is a perspective view showing the liquid crystal display device of the present embodiment.
FIG. 13 is a cross-sectional view of the liquid crystal display device.
14A and 14B are diagrams for explaining the operation of the viewing angle widening film.
FIGS. 15A to 15F are cross-sectional views sequentially showing the manufacturing process of the viewing angle widening film of this embodiment.
12, 13, 14 (A), (B), and 15 (A) to (F), the same reference numerals are used for the same components as those used in the first and second embodiments. The detailed explanation is omitted.

  In the first and second embodiments, the plurality of light diffusion portions are formed in a strip shape so as to extend in the y-axis direction. On the other hand, in the viewing angle widening film 62 of this embodiment, as shown in FIGS. 12 and 13, the light diffusion portion 63 composed of the first layer 64 and the second layer 65 is parallel to one surface of the base material 39. The horizontal cross section when cut by the surface (xy plane) is circular, the area of the horizontal cross section on the base material 39 side that becomes the light emission end face 63a is small, and the area of the horizontal cross section gradually increases as the distance from the base material 39 increases. ing. That is, the shape of each light diffusion portion 63 is substantially a truncated cone shape.

  The plurality of light diffusion portions 63 are regularly arranged in a scattered manner on the base material 39. Among the plurality of light diffusion units 63, for example, the light diffusion units 63 in each column arranged in the y-axis direction are arranged at a constant pitch, and the light diffusion units 63 in each row arranged in the x-axis direction are arranged at a constant pitch. In addition, the light diffusing units 63 in a predetermined column arranged in the y-axis direction and the light diffusing units 63 in the column adjacent to the column in the x-axis direction are arranged at positions shifted by ½ pitch in the y-axis direction. Has been. The diameter of the light emission end face 63a of the light diffusion part 63 is, for example, 20 μm, and the pitch between the adjacent light diffusion parts 63 is 25 μm. Since the plurality of light diffusion portions 63 are scattered on the base material 39, the light shielding layer 66 of this embodiment is continuously formed on the base material 39.

  In addition, each light diffusion portion 63 has a two-layer structure of the first layer 64 and the second layer 65 made of different types of transparent negative resists, and the inclination angle of the side surface 64 c of the first layer 64 and the second layer 65. The inclination angle of the side surface 65c is preferably 60 ° or more and less than 90 °, and the relationship between these two inclination angles is the same as in the first embodiment. The configuration other than the light diffusing unit 63 is the same as that of the first embodiment.

  In the case of the present embodiment, as shown in FIG. 14A, the cross-sectional shape of the light diffusing unit 63 in the xz plane is the same as that of the light diffusing unit 40 of the first embodiment (see FIG. 4A). Therefore, the effect that the viewing angle widening film 62 expands the angle distribution of light in the xz plane is the same as that of the first embodiment. However, when viewed from the front direction (z-axis direction) of the screen of the liquid crystal display device 61, the shape of the light diffusion portion 40 of the first embodiment is a line shape, as shown in FIG. The shape of the light diffusion portion 63 of this embodiment is a circle. Therefore, the light L totally reflected by the side surface 68c of the light diffusing unit 63 diffuses in all 360 degrees. Therefore, according to the viewing angle widening film 62 of the present embodiment, the viewer visually recognizes a good display from all directions with respect to the screen as well as the horizontal direction of the screen as in the first and second embodiments. be able to.

  In the manufacturing process of the viewing angle widening film 62 of this embodiment, as shown in FIG. 15B, the photomask 67 used when forming the light shielding layer 66 has a plurality of circular light shielding patterns 68. The manufacturing process itself of the viewing angle widening film 62 is the same as that of the first embodiment.

  Also in the liquid crystal display device 61 of this embodiment, the same effects as those of the first and second embodiments can be obtained, such that a viewing angle widening film capable of exhibiting desired light diffusion performance can be produced without complicating the manufacturing process. It is done.

[First Modification of Third Embodiment]
In the above embodiment, as shown in FIG. 16A, the example of the light diffusing portion 63 having a circular planar shape is shown. However, for example, as shown in FIG. The part 63e may be used. Alternatively, as shown in FIG. 16C, a light diffusion portion 63f having a rectangular planar shape may be used. Alternatively, as shown in FIG. 16D, a light diffusing portion 63g having a square planar shape may be used. Alternatively, as shown in FIG. 16E, a light diffusion portion 63h having an octagonal planar shape may be used. Alternatively, as illustrated in FIG. 16F, a light diffusion portion 63i having a shape in which two opposite sides of a rectangle are curved outward may be used. Alternatively, as shown in FIG. 16G, an elliptical light diffusing portion 63j may be used.

For example, in the rectangular light diffusion portion 63f shown in FIG. 17A, the diffusion of the light L4 in the direction perpendicular to the long side is stronger than the diffusion of the light L5 in the direction perpendicular to the short side. Therefore, it is possible to realize a viewing angle widening film in which the intensity of light diffusion differs in the vertical direction (up and down direction) and the horizontal direction (left and right direction) depending on the length of the side.
With the octagonal light diffusing portion 63h shown in FIG. 17B, the light L is concentrated in the vertical direction, the horizontal direction, and the oblique 45 degree direction, in which viewing angle characteristics are particularly important in liquid crystal display devices. Can be diffused.
Thus, when anisotropy of the viewing angle is required, different light diffusion characteristics can be obtained by appropriately changing the shape of the light diffusion portion.

[Second Modification of Third Embodiment]
FIG. 18 is a schematic diagram showing a second modification of the viewing angle widening film of the above embodiment. FIG. 18A is a perspective view of the viewing angle widening film 62A of this modification, and FIG. 18B is a cross-sectional view of the viewing angle widening film 62A of this modification.
In the above embodiment, the plurality of light diffusing portions 63 composed of the first layer 64 and the second layer 65 are independently formed on one surface of the base material 39. However, the viewing angles shown in FIGS. Like the magnifying film 62A, a plurality of light diffusion portions 63A including the first layer 64A and the second layer 65A may be connected at least in part. In this modification, the second layer 65A is connected in two adjacent light diffusion portions 63A, and the two first layers 64A share one second layer 65A.

  According to this structure, each light diffusion part 63A becomes difficult to fall down, and the form stability of the viewing angle expansion film 62A improves. Further, when the second layer 65A is connected, the ratio of the light incident on the viewing angle widening film 62A being absorbed by the light shielding layer 66A is reduced, so that the light use efficiency is improved.

[Fourth embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIGS. 19 and 20.
The basic configuration of the liquid crystal display device of the present embodiment is the same as that of the third embodiment, and only the arrangement of the light diffusion portion of the viewing angle widening film is different from that of the third embodiment. Therefore, in this embodiment, description of the basic composition of a liquid crystal display device is abbreviate | omitted, and only a viewing angle expansion film is demonstrated.
FIG. 19 is a perspective view showing the liquid crystal display device of the present embodiment.
20A to 20F are cross-sectional views sequentially showing the manufacturing process of the viewing angle widening film of this embodiment.
In FIGS. 19 and 20A to 20F, the same reference numerals are given to the same components as those used in the first to third embodiments, and the detailed description thereof will be omitted.

  In the third embodiment, the plurality of light diffusion portions 63 are regularly arranged. On the other hand, in the viewing angle widening film 62B of the present embodiment, as shown in FIG. 19, a plurality of light diffusion portions 63 are arranged randomly (non-periodically). Therefore, although the pitch between the adjacent light diffusion parts 63 is not constant, the average pitch obtained by averaging the pitches between the adjacent light diffusion parts 63 is set to 25 μm. Other configurations are the same as those of the third embodiment.

  In the manufacturing process of the viewing angle widening film 62B of the present embodiment, as shown in FIG. 20B, the photomask 67B used when forming the light shielding layer 66B has a plurality of circular light shielding patterns 68 arranged at random. Have. When designing the photomask 67B, first, the light shielding patterns 68 are first regularly arranged at a constant pitch, and then, for example, the center points of the light shielding patterns 68, for example, the center points of the light shielding patterns 68 are used. By providing fluctuations in the reference position data and varying the position of the light shielding pattern 68, a photomask 67B having a plurality of light shielding patterns 68 arranged at random can be manufactured. The manufacturing process of the viewing angle widening film 62B itself is the same as in the first to third embodiments.

  Also in the liquid crystal display device 61B of the present embodiment, the first to third embodiments in which the viewing angle widening film 62B capable of exhibiting desired light diffusion performance in all directions of the screen can be manufactured without complicating the manufacturing process. The same effect can be obtained. Further, since the light diffusing portions 63 are randomly arranged, moire due to interference does not occur with the regular arrangement of the pixels of the liquid crystal panel 4, and the display quality can be maintained.

[Fifth Embodiment]
Hereinafter, a fifth embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the liquid crystal display device of this embodiment is the same as that of the third and fourth embodiments, and the configuration of the light diffusion portion of the viewing angle widening film is only different from that of the third and fourth embodiments. Therefore, in this embodiment, description of the basic composition of a liquid crystal display device is abbreviate | omitted, and only a viewing angle expansion film is demonstrated.
FIG. 21 is a perspective view showing the liquid crystal display device of the present embodiment.
FIGS. 22A and 22B are views for explaining the operation of the viewing angle widening film.
FIGS. 23A to 23F are cross-sectional views sequentially showing the manufacturing process of the viewing angle widening film of this embodiment.
In FIG. 21, FIG. 22 (A), (B), and FIG. 23 (A) to (F), the same reference numerals are given to the same components as those used in the third and fourth embodiments. Detailed description thereof will be omitted.

  In the third and fourth embodiments, the plurality of light diffusion portions 63 have the same dimensions. On the other hand, in the viewing angle widening film 62C of the present embodiment, as shown in FIG. 21, the dimensions (diameters) of the plurality of light diffusion portions 63C are different. For example, the diameters of the plurality of light diffusion portions 63C are distributed in the range of 5 to 30 μm. That is, the plurality of light diffusion portions 63C have a plurality of types of dimensions. The plurality of light diffusion parts 63C are randomly arranged in a plane as in the fourth embodiment. Other configurations are the same as those of the fourth embodiment.

  In the case of the present embodiment, as shown in FIG. 22A, the cross-sectional shape of the light diffusing portion 63C in the xy plane is a circle similar to that of the light diffusing portion 63 of the fourth embodiment (see FIG. 22B). . Therefore, the effect that the viewing angle widening film 62C expands the angular distribution of light in the xz plane is the same as that of the fourth embodiment. However, in the fourth embodiment, all of the plurality of light diffusing parts 63 have the same dimensions, but in this embodiment, the dimensions of the plurality of light diffusing parts 63C are different as shown in FIG. Yes. As shown in FIG. 22B, when the light diffusing portions 63 having a fixed shape are randomly arranged, a portion where a plurality of light diffusing portions 63 are arranged in a straight line is generated. On the other hand, as shown in FIG. 22A, when the light diffusion portions 63C having different shapes are randomly arranged, the ratio of the plurality of light diffusion portions 63C arranged in a straight line is reduced. In other words, by changing the dimensions of the plurality of light diffusing portions into a plurality of types or randomly changing, for example, filling the space between the circular light diffusing portions with a large diameter with a circular light diffusing portion with a small diameter, etc. The arrangement density of the light diffusion parts can be increased. As a result, the ratio of light shielded by the light shielding layer can be reduced and the light utilization efficiency can be increased.

  The manufacturing process of the viewing angle widening film 62C of this embodiment is the same as that of the third embodiment. However, as shown in FIG. 22B, the photomask 67C used for forming the light shielding layer 66C has a plurality of different dimensions. Only the point which has the opening pattern 68C is different from the fourth embodiment.

  Also in the liquid crystal display device 61C of the present embodiment, the first to third embodiments in which the viewing angle widening film 62C capable of exhibiting desired light diffusion performance in all directions of the screen can be manufactured without complicating the manufacturing process. The same effect can be obtained. In addition to the plurality of light diffusing portions 63C being randomly arranged, the size of the light diffusing portion 63C is also different, so that moire fringes due to the light diffraction phenomenon can be more reliably suppressed.

[Sixth Embodiment]
Hereinafter, a sixth embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the liquid crystal display device of this embodiment is the same as that of the third embodiment, and only the configurations of the light diffusion portion and the light shielding layer of the viewing angle widening film are different from those of the third embodiment. Therefore, in this embodiment, description of the basic composition of a liquid crystal display device is abbreviate | omitted, and only a viewing angle expansion film is demonstrated.
FIG. 24 is a perspective view showing the liquid crystal display device of the present embodiment.
25A and 25B are diagrams for explaining the operation of the viewing angle widening film.
FIGS. 26A to 26F are cross-sectional views sequentially showing the manufacturing process of the viewing angle widening film of this embodiment.
24, 25 (A), (B), and FIGS. 26 (A) to (F), the same reference numerals are given to the same components as those used in the third embodiment, and the details thereof are described. The detailed explanation is omitted.

  In the third embodiment, a plurality of light diffusion portions 63 formed on one surface of the base material 39 and a light shielding layer 66 formed on a region other than the formation region of the light diffusion portion 63 on one surface of the base material 39 are provided. The plurality of light diffusion portions 63 are arranged in a scattered manner when viewed from the normal direction of one surface of the base material 39, and the light shielding layer 66 is continuously formed in a region other than the formation region of the light diffusion portion 63. On the other hand, the viewing angle widening film 72 of the present embodiment is formed in a plurality of light shielding layers 76 formed on one surface of the base material 39 and in a region other than the region where the light shielding layer 76 is formed on one surface of the base material 39. A plurality of light shielding layers 76 are arranged in a scattered manner when viewed from the normal direction of one surface of the base material 39, and the light diffusion portions 73 are disposed in a region other than the region where the light shielding layer 76 is formed. It is formed continuously.

  The plurality of light shielding layers 76 are regularly arranged in a scattered manner on the base material 39. Among the plurality of light shielding layers 76, for example, the light shielding layers 76 in each column arranged in the y-axis direction are arranged at a constant pitch, and the light shielding layers 76 in each row arranged in the x-axis direction are arranged at a constant pitch. Further, the light shielding layers 76 in a predetermined row arranged in the y-axis direction and the light shielding layers 76 adjacent to the row in the x-axis direction are arranged at positions shifted by ½ pitch in the y-axis direction. Yes.

  In this embodiment, the planar shape when each light shielding layer 76 is viewed from the normal direction of the base material 39 is a circle. The diameter of each light shielding layer 76 is, for example, 10 μm, and the pitch between adjacent light shielding layers 76 is 20 μm. Since the plurality of light shielding layers 76 are scattered on the base material 39, the light diffusion portion 73 of the present embodiment is continuously formed on the base material 39.

  In the formation region of the light shielding layer 76 in the viewing angle widening film 72, the cross-sectional area when cut along a plane parallel to one surface of the base material 39 is large on the light shielding layer 76 side, and gradually decreases as the distance from the light shielding layer 76 increases. A hollow portion 77 is formed. That is, the hollow portion 77 has a so-called forward tapered substantially truncated cone shape when viewed from the base material 39 side. Air exists in the hollow portion 77. The part other than the hollow part 77 of the viewing angle widening film 72, that is, the part where the light diffusion part 73 is continuously present is a part that contributes to the transmission of light. The light incident on the light diffusing portion 73 is totally reflected at the interface between the light diffusing portion 73 and the hollow portion 77, and is guided in a state of being substantially confined inside the light diffusing portion 73, via the base material 39. Is emitted to the outside.

In the case of this embodiment, since air exists in the hollow portion 77, if the light diffusion portion 73 is formed of, for example, a transparent resin, the side surface 73c of the light diffusion portion 73 becomes an interface between the transparent resin and air. . Here, the difference in refractive index between the inside and the outside of the light diffusing portion 73 is such that the periphery of the light diffusing portion 73 is made of other general low refractive index materials when the hollow portion 77 is filled with air. Greater than being filled. Therefore, according to Snell's law, the incident angle range in which light is totally reflected by the side surface 73c of the light diffusion portion 73 is wide. As a result, light loss is further suppressed, and high luminance can be obtained.
The hollow portion 77 may be filled with an inert gas such as nitrogen instead of air. Alternatively, the inside of the hollow portion 77 may be in a vacuum state.

  In addition, each light diffusion portion 73 has a two-layer structure of a first layer 74 and a second layer 75 made of different types of transparent negative resists, and the inclination angle of the side surface 74 c of the first layer 74 and the second layer 75. The inclination angle of the side surface 75c is preferably 60 ° or more and less than 90 °, and the relationship between these two inclination angles is the same as that of the third embodiment. The configuration other than the light shielding layer 76 and the light diffusion portion 73 is the same as that of the third embodiment.

  In the case of the present embodiment, as shown in FIG. 25A, out of the light emitted from the liquid crystal panel 4 and incident on the viewing angle widening film 72, near the light incident end face 73 b in the vicinity of the center of the light diffusion portion 73. The light L1 incident substantially perpendicularly passes through the light diffusion portion 73 as it is without being totally reflected by the side surface 73c of the light diffusion portion 73. In addition, the light L2 incident substantially perpendicular to the light incident end surface 73b at the peripheral edge of the light diffusing portion 73 is incident on the side surface 73c of the light diffusing portion 73 at an incident angle larger than the critical angle. Is totally reflected by the side surface 73c. Then, the totally reflected light is further refracted by the light emitting end face 73a of the light diffusing portion 73 and emitted in a direction that forms a large angle with respect to the normal direction of the light emitting end face 73a. On the other hand, the light L3 incident obliquely to the light incident end surface 73b of the light diffusing portion 73 is incident on the side surface 73c of the light diffusing portion 73 at an incident angle smaller than the critical angle. The light is transmitted and absorbed by the light shielding unit 76.

  As a result of the above operation, as shown in FIG. 25B, the light distribution L1 and L2 incident substantially perpendicular to the viewing angle widening film 72 has a wider angular distribution than before entering the viewing angle widening film 72. The light is emitted from the viewing angle widening film 72 in a state. Therefore, even if the observer tilts the line of sight from the front direction (normal direction) of the liquid crystal panel 4, a good display can be visually recognized. In particular, in the case of the present embodiment, since the planar shape of the side surface 73c (reflection surface) of the light diffusing unit 73 is circular, the angular distribution spreads in all directions centered on the normal direction of the screen of the liquid crystal panel 4. Therefore, the observer can visually recognize a good display in all directions. That is, the viewing angle of the liquid crystal panel 4 can be enlarged by using the viewing angle widening film 72. On the other hand, the light L3 obliquely incident on the viewing angle widening film 72 is light that is obliquely transmitted through the liquid crystal panel 4, and is light that is different from a desired retardation, that is, light that causes a reduction in display contrast. . The viewing angle widening film 72 of this embodiment can increase the display contrast by cutting such light with the light shielding layer 76.

Next, a manufacturing method of the liquid crystal display device 71 having the above configuration will be described with reference to FIG.
Below, it demonstrates centering on the manufacturing process of the viewing angle expansion film 72. FIG.

First, as shown in FIG. 26A, a triacetyl cellulose base material 39 having a 10 cm square and a thickness of 100 μm is prepared, and a light shielding layer material is formed on one surface of the base material 39 by using a spin coating method. A black negative resist containing carbon is applied to form a coating film 44 having a thickness of 150 nm.
Next, the base material 39 on which the coating film 44 is formed is placed on a hot plate, and the coating film is pre-baked at a temperature of 90 ° C. Thereby, the solvent in the black negative resist is volatilized.

Next, using an exposure apparatus, exposure is performed by irradiating the coating film 44 with light E through a photomask 78 in which a plurality of opening patterns 79 having a circular planar shape are formed. At this time, an exposure apparatus using a mixed line of i-line having a wavelength of 365 nm, h-line having a wavelength of 404 nm, and g-line having a wavelength of 436 nm is used. The exposure dose is 100 mJ / cm ² .

  After performing exposure using the above-described photomask 78, the coating film 44 made of a black negative resist is developed using a dedicated developer, dried at 100 ° C., and as shown in FIG. A plurality of light shielding layers 76 having a circular planar shape are formed on one surface of the base material 39. In the case of the present embodiment, in the next step, the transparent negative resist is exposed using the light shielding layer 76 made of black negative resist as a mask to form the hollow portion 77. Therefore, the position of the opening pattern 79 of the photomask 78 corresponds to the position where the hollow portion 77 is formed. The circular light shielding layer 76 corresponds to a non-formation region (hollow portion 77) of the light diffusion portion 73 in the next step. The plurality of opening patterns 79 are all circular patterns having a diameter of 10 μm, and the interval (pitch) between adjacent opening patterns 79 is 20 μm. The pitch of the opening patterns 79 is preferably smaller than the interval (pitch, for example, 150 μm) between the pixels of the liquid crystal panel 4. As a result, at least one light shielding layer 76 is formed in the pixel. For example, when combined with a liquid crystal panel having a small pixel pitch used for a mobile device or the like, a wide viewing angle can be achieved.

  In the present embodiment, the light shielding layer 76 is formed by a photolithography method using a black negative resist. However, instead of this configuration, a photomask in which the opening pattern 79 and the light shielding pattern of the present embodiment are reversed is used. Also, a positive resist having light absorption can be used. Or you may form directly the light shielding layer 76 patterned using the vapor deposition method, the printing method, the inkjet method, etc. FIG.

  Next, a negative photosensitive resin material in which a plurality of materials that are incompatible with each other is mixed is prepared. The negative photosensitive resin material is a material that forms a phase separation structure from a mixed liquid phase. For example, the negative photosensitive resin material is a mixture of a transparent negative resist made of acrylic resin as the first material and a transparent negative resist made of epoxy resin as the second material.

  Next, as shown in FIG. 26C, a negative photosensitive resin material is applied to the upper surface of the light shielding layer 76 by using a spin coating method to form a coating film 48 having a thickness of 50 μm. Next, the base material 39 on which the coating film 48 is formed is placed on a hot plate, and the coating film 48 is pre-baked at a temperature of 95 ° C. Thereby, while evaporating the solvent, the negative photosensitive resin material is phase-separated, and a plurality of negative photosensitive resin layers (the coating film 49 made of acrylic resin and the epoxy resin separated in the normal direction of one surface of the base material 39) are separated. A coating film 50) made of resin is formed. In this way, the two-layer coating films 49 and 50 made of different types of transparent negative resists are formed. For example, the film thickness of the coating film 49 is about 25 μm, and the film thickness of the coating film 50 is about 25 μm.

Next, as shown in FIG. 26D, exposure is performed by irradiating the coating films 49 and 50 with the diffused light F from the base material 39 side using the light shielding layer 76 as a mask. At this time, an exposure apparatus using a mixed line of i-line having a wavelength of 365 nm, h-line having a wavelength of 404 nm, and g-line having a wavelength of 436 nm is used. The exposure amount is 500 mJ / cm ² . In the exposure process, parallel light or diffused light is used. Further, as means for irradiating the base material 39 with the parallel light emitted from the exposure apparatus as diffused light F, a diffusion plate having a haze of about 50 is disposed on the optical path of the light emitted from the exposure apparatus. By performing exposure with the diffused light F, the coating films 49 and 50 having a two-layer structure are exposed radially so as to spread outward from the non-formation region of the light shielding layer 76. As a result, a forward tapered hollow portion 77 is formed, and a reverse tapered side surface is formed in the portion of the light diffusion portion 73 facing the hollow portion 77.
Thereafter, the base material 39 after the exposure process is placed on a hot plate, and post-exposure baking (PEB) of the coating films 49 and 50 is performed at a temperature of 95 ° C.

Next, the coatings 49 and 50 made of a transparent negative resist are developed using a dedicated developer, post-baked at 100 ° C., and the first layer 74 and the second layer 74 as shown in FIG. A light diffusion portion 73 made of is formed on one surface of the base material 39.
Through the above steps, the viewing angle widening film 72 of this embodiment is completed. The total light transmittance of the viewing angle widening film 72 is preferably 90% or more. When the total light transmittance is 90% or more, sufficient transparency is obtained, and the optical performance required for the viewing angle widening film 72 can be sufficiently exhibited. The total light transmittance is in accordance with JIS K7361-1.

  In the above example, the liquid resist is applied at the time of forming the light shielding layer 76 and the light diffusing portion 73, but instead of this configuration, a film resist is applied to one surface of the base material 39. Also good.

Finally, as shown in FIG. 24, the completed viewing angle widening film 72 is placed with the base material 39 facing the viewing side and the light diffusion portion 73 facing the second polarizing plate 5 with the adhesive layer 8 interposed therebetween. Is attached to the liquid crystal display body 6.
Through the above steps, the liquid crystal display device 71 of the present embodiment is completed.

  Also in the liquid crystal display device 71 of the present embodiment, the same effect as in the third embodiment that a viewing angle widening film capable of exhibiting desired light diffusion performance can be produced without complicating the manufacturing process.

  Moreover, according to this structure, the several hollow part 77 provided in the viewing angle expansion film 72 is isolated, and the part used as the light-diffusion part 73 becomes a continuous shape in the surface. Thereby, for example, even if the density of the hollow portion 77 is increased to reduce the volume of the light diffusion portion 73 in order to increase the degree of light diffusion, a sufficient contact area between the light diffusion portion 73 and the base material 39 can be secured. Therefore, the adhesion between the light diffusing portion 73 and the base material 39 is strong. Therefore, the light diffusing portion 73 is not likely to be defective due to external force or the like, and a desired light diffusing function can be achieved.

  Further, since the light F is applied to the transparent resin layer from the back side of the base material 39 using the light shielding layer 76 as a mask, the light diffusion portion 73 is in a self-aligned (self-aligned) state with the non-forming region of the light shielding layer 76. It is formed. As a result, the light diffusion portion 73 and the light shielding layer 76 do not overlap each other, and the light transmittance can be reliably maintained. In addition, since precise alignment work is unnecessary, the time required for manufacturing can be shortened.

  Moreover, according to this structure, since the volume of each hollow part 77 is the same, the volume of resin removed when developing a transparent resin layer becomes constant. For this reason, the development speed of each hollow part 77 becomes constant in the process of forming each hollow part 77, and a desired tapered shape can be formed. As a result, the uniformity of the fine shape of the viewing angle widening film 72 is increased, and the yield is improved.

  In this embodiment, as shown in FIG. 27A, an example of the light shielding layer 76 having a circular planar shape is shown. However, for example, as shown in FIG. 27B, the planar shape is a square. The light shielding layer 76b may be used. Alternatively, as illustrated in FIG. 27C, a light shielding layer 76c having a regular octagonal planar shape may be used. Alternatively, as shown in FIG. 27D, a light shielding layer 76d having a shape in which two opposite sides of a square are curved outward may be used. Alternatively, as shown in FIG. 27E, a light shielding layer 76e having a shape in which two rectangles intersect in two orthogonal directions may be used. Alternatively, as shown in FIG. 27F, an elongated oval light shielding layer 76f may be used. Alternatively, as shown in FIG. 27G, an elongated rectangular light shielding layer 76g may be used. Alternatively, as shown in FIG. 27H, an elongated octagonal light shielding layer 76h may be used. Alternatively, as shown in FIG. 27I, a light shielding layer 76i having a shape in which two opposite sides of an elongated rectangle are curved outward may be used. Alternatively, as shown in FIG. 27J, a light shielding layer 76j having a shape in which two rectangles having different aspect ratios intersect each other in two orthogonal directions may be used.

  Since the planar shape of the light shielding layer 76 of this embodiment is a circle as shown in FIG. 27A, the side surface 44c of the light diffusion portion 73, that is, the cross-sectional shape of the reflection surface is also a circle. Therefore, the light reflected by the side surface 44c of the light diffusion portion 73 is diffused in all directions at 360 degrees. On the other hand, for example, in the case of a square light shielding layer 76b shown in FIG. 27B, light diffuses in a direction perpendicular to each side of the square. In the rectangular light shielding layer 76g shown in FIG. 27G, the diffusion of light in the direction perpendicular to the long side is stronger than the diffusion of light in the direction perpendicular to the short side. Therefore, it is possible to realize a light diffusion sheet having different light diffusion strengths in the vertical direction (up and down direction) and the horizontal direction (left and right direction) depending on the length of the side. In addition, in the case of the octagonal light shielding layer 76c shown in FIG. 27C, light is concentrated in the vertical direction, the horizontal direction, and the oblique 45 degree direction, in which viewing angle characteristics are particularly important in liquid crystal display devices. Can be diffused. Thus, when anisotropy of the viewing angle is required, different light diffusion characteristics can be obtained by appropriately changing the shape of the light shielding portion.

[First Modification of Sixth Embodiment]
FIG. 28 is a schematic view showing a first modification of the viewing angle widening film of the above embodiment. FIG. 28A is a perspective view of the viewing angle widening film 72A of this modification, and FIG. 28B is a cross-sectional view of the viewing angle widening film 72A of this modification.
In the above embodiment, the plurality of light shielding layers 76 are independently formed on one surface of the base material 39. However, like the viewing angle widening film 72A shown in FIGS. May be connected at least partially. In this modification, two adjacent light shielding layers 76A are connected, and the hollow portion 77A formed in the region where the light shielding layers 76A are connected is also partly connected. Further, as shown in FIG. 28B, the hollow portion 77A may be blocked by a light diffusion portion 73A (a portion where the second layer 75A is connected).

  Also in this configuration, a sufficient contact area between the light diffusing portion 73A and the base material 39 can be secured, and thus the adhesion between the light diffusing portion 73A and the base material 39 is strong. In addition, when the second layer 75A is connected, the rate at which the light incident on the viewing angle widening film 72A is absorbed by the light shielding layer 76 is reduced, so that the light use efficiency is improved.

[Seventh embodiment]
Hereinafter, a seventh embodiment of the present invention will be described with reference to FIGS. 29 and 30. FIG.
The basic configuration of the liquid crystal display device of this embodiment is the same as that of the sixth embodiment, and only the arrangement of the light shielding layer of the viewing angle widening film is different from that of the sixth embodiment. Therefore, in this embodiment, description of the basic composition of a liquid crystal display device is abbreviate | omitted, and only a viewing angle expansion film is demonstrated.
FIG. 29 is a perspective view showing the liquid crystal display device of the present embodiment.
30 (A) to 30 (E) are cross-sectional views sequentially showing the manufacturing process of the viewing angle widening film of this embodiment.
29 and 30A to 30E, the same reference numerals are given to the same components as those used in the sixth embodiment, and the detailed description thereof will be omitted.

  In the sixth embodiment, the plurality of light shielding layers 76 having a circular planar shape are regularly arranged. On the other hand, in the viewing angle widening film 72B of this embodiment, as shown in FIG. 29, a plurality of light shielding layers 76 having a circular planar shape are randomly (non-periodically) arranged. Accordingly, a plurality of hollow portions 77 formed at the same position as the plurality of light shielding layers 76 are also randomly arranged on the base material 39. Other configurations are the same as those of the sixth embodiment.

  The manufacturing process of the viewing angle widening film 72B of this embodiment is the same as that of the sixth embodiment, as shown in FIGS. However, the photomask 78B used in the exposure process of the black negative resist for forming the light shielding portion shown in FIG. 30A is different from the photomask 78 used in the sixth embodiment. In the photomask 78B of this embodiment, as shown in FIG. 30A, a plurality of opening patterns 79 having a circular planar shape are randomly arranged. By irradiating the black negative resist coating film 44 with light L through the photomask 78B and developing it, as shown in FIG. 30 (B), a plurality of light-shielding layers randomly arranged on the substrate 39 76 is formed.

  Also in the viewing angle widening film 72B of the present embodiment, a defect of the light diffusion portion 73B due to an external force or the like is not easily generated, and a precise alignment operation that can maintain a desired light diffusion function without causing a decrease in light transmittance is unnecessary. In addition, the same effect as in the sixth embodiment that the time required for manufacturing can be shortened can be obtained.

  Also, according to this configuration, since the plurality of light shielding layers 76 are randomly arranged in a plane, moire due to interference does not occur with the regular arrangement of the pixels of the liquid crystal panel 4, and the display quality is improved. Can be maintained.

  In the case of this embodiment, even if the planar arrangement of the hollow portions 77 is random, the volume of each hollow portion 77 is the same, so the volume of the resin removed when developing the transparent resin layer is constant. It becomes. For this reason, the development speed of each hollow part 77 becomes constant in the process of forming each hollow part 77, and a desired tapered shape can be formed. As a result, the uniformity of the fine shape of the viewing angle widening film 72B is increased, and the yield is improved.

[Eighth embodiment]
Hereinafter, an eighth embodiment of the present invention will be described with reference to FIGS. 31 and 32.
The basic configuration of the liquid crystal display device of this embodiment is the same as that of the sixth and seventh embodiments, and only the configuration of the light shielding layer of the viewing angle widening film is different from that of the sixth and seventh embodiments. Therefore, in this embodiment, description of the basic composition of a liquid crystal display device is abbreviate | omitted, and only a viewing angle expansion film is demonstrated.
FIG. 31 is a perspective view showing the liquid crystal display device of the present embodiment.
FIGS. 32A to 32E are cross-sectional views sequentially showing the manufacturing process of the viewing angle widening film of this embodiment.
Further, in FIGS. 31 and 32A to 32E, the same reference numerals are given to the same components as those used in the sixth and seventh embodiments, and the detailed description thereof will be omitted.

  In the sixth and seventh embodiments, all of the plurality of light shielding layers 76 have the same dimensions. On the other hand, in the viewing angle widening film 72C of the present embodiment, as shown in FIG. 31, the dimensions (diameters) of the plurality of light shielding layers 76C are different. For example, the diameters of the plurality of light shielding layers 76C are distributed in the range of 10 to 25 μm. That is, the plurality of light shielding layers 76C have a plurality of types of dimensions. The plurality of light shielding layers 76C are randomly arranged in a plane as in the seventh embodiment. Of the plurality of hollow portions 77C, the volume of at least one hollow portion 77C is different from the volume of the other hollow portions 77C. Other configurations are the same as those of the seventh embodiment.

  The manufacturing process of the viewing angle widening film 72C is the same as that in the sixth and seventh embodiments. However, as shown in FIG. 32A, the photomask 78C used for forming the light shielding layer 76C has a plurality of openings having different dimensions. Only the point having the pattern 79C is different from the seventh embodiment.

  Also in the viewing angle widening film 72C of the present embodiment, a defect of the light diffusion portion 73C due to an external force or the like is hardly generated, and a precise alignment operation that can maintain a desired light diffusion function without causing a decrease in light transmittance is unnecessary. In addition, the same effect as in the sixth and seventh embodiments can be obtained that the time required for manufacturing can be shortened. In the case of this embodiment, in addition to the plurality of light shielding layers 76C being randomly arranged, the size of the light shielding layer 76C is also different, so that moire fringes due to the light diffraction phenomenon can be more reliably suppressed. Moreover, since the volume of at least one hollow part 77C differs from the volume of the other hollow part 77C, light diffusibility can be improved.

[Ninth Embodiment]
The ninth embodiment of the present invention will be described below with reference to FIGS. 33 and 34.
The basic configuration of the liquid crystal display device of this embodiment is the same as that of the first embodiment, and the first embodiment is that a scattering layer 82 having light diffusibility is formed between the liquid crystal display body 6 and the adhesive layer 8. Only the form is different. Therefore, in this embodiment, the description of the basic configuration of the liquid crystal display device is omitted.
FIG. 33 is a perspective view showing the liquid crystal display device 81 of the present embodiment.
FIGS. 34A and 34B are diagrams for explaining the operation of the scattering layer 82.
33, FIG. 34 (A), and (B), the same code | symbol is attached | subjected to the same component as drawing used in 1st Embodiment, and the detailed description is abbreviate | omitted. In FIG. 34A, the adhesive layer 8 is not shown for convenience.

  As shown in FIG. 33, the scattering layer 82 is disposed between the liquid crystal display body 6 and the adhesive layer 8. The scattering layer 82 is a layer containing particulate scatterers. Examples of scatterer materials include glasses, acrylic polymers, olefin polymers, vinyl polymers, cellulose polymers, amide polymers, fluorine polymers, urethane polymers, silicone polymers, imide polymer resins, etc. A material made of an appropriate transparent substance made of can be used. Alternatively, the scatterer may be a bubble diffused in the scattering layer 80. Other than these transparent substances, scatterers and reflectors that do not absorb light can be used. The shape of each scatterer can be formed in various shapes such as a spherical shape, an elliptical spherical shape, a flat plate shape, and a polygonal cube. The scattering layer 82 preferably has a haze of 50 or less. More preferably, the scattering layer 82 has a haze of 20 or less.

  In the present embodiment, the scattering layer 82 is disposed between the liquid crystal display body 6 and the adhesive layer 8, but is not limited thereto. For example, the adhesive layer 8 itself may have light scattering properties.

  In the present embodiment, as shown in FIG. 34A, a scattering layer 82 is disposed on the light incident end face 40b side of the light diffusing section 40. Thereby, the light L incident perpendicularly to the light incident end face 40 b of the light diffusing portion 40 is diffused by the scattering layer 82. For this reason, light of various angles is incident on the light diffusion unit 40. Light incident on the light diffusing unit 40 at various angles is totally reflected by the side surface 40c, then changes the angle, propagates at various angles, sequentially passes through the first layer 42 and the base material 39, and is emitted to the outside. The

  On the other hand, as shown in FIG. 34B, in the case of the viewing angle widening film 107 in which the scattering layer is not disposed, the light L incident perpendicularly to the light incident end surface 140b of the light diffusion unit 140 is specified. The injection is concentrated on the diffusion angle. As a result, light cannot be uniformly diffused over a wide angle range, and a bright display can be obtained only with a specific viewing angle.

  Thus, in the case of this embodiment, since the scattering layer 82 is disposed on the light incident end face 40b side of the light diffusing unit 40, the light diffusion angle can be prevented from being concentrated to one. As a result, the light diffusion characteristics of the viewing angle widening film 7 can be made smoother, and a bright display can be obtained with a wide viewing angle.

[Tenth embodiment]
The tenth embodiment of the present invention will be described below with reference to FIGS. 35 and 36.
The basic configuration of the liquid crystal display device of the present embodiment is the same as that of the first embodiment, and the first embodiment is that a scattering layer 93 having light diffusibility is formed outside the base material 39 of the viewing angle widening film 92. Only the form is different. Therefore, in this embodiment, the description of the basic configuration of the liquid crystal display device is omitted.
FIG. 35 is a perspective view showing the liquid crystal display device 91 of the present embodiment.
36A and 36B are diagrams for explaining the operation of the scattering layer 93. FIG.
35, 36A, and 36B, the same reference numerals are given to the same components as those used in the first embodiment, and detailed description thereof is omitted. In FIG. 36A, the adhesive layer 8 is not shown for convenience.

  As shown in FIG. 35, the scattering layer 93 is disposed outside the base material 39 of the viewing angle widening film 92. The scattering layer 93 is a layer containing particulate scatterers. The scattering layer 93 preferably has a haze of 50 or less. More preferably, the scattering layer 82 has a haze of 20 or less. In addition, since the scattering layer 93 is provided in the outermost surface of the viewing angle expansion film 92, it is preferable that there is no backscattering.

  In the present embodiment, the scattering layer 93 is disposed outside the base material 39, but is not limited thereto. For example, the base material 39 itself may have light scattering properties.

  In the case of the present embodiment, as shown in FIG. 36A, a scattering layer 93 is disposed on the outermost surface of the viewing angle widening film 92. Thereby, the light L incident perpendicularly to the light incident end face 40 b of the light diffusing portion 40 is diffused by the light diffusing portion 40 and further diffused by the scattering layer 93. For this reason, light of various angles is emitted from the scattering layer 93.

  On the other hand, as shown in FIG. 36B, in the case of the viewing angle widening film 107 in which the scattering layer is not disposed, the light L incident perpendicularly to the light incident end surface 140b of the light diffusion portion 140 is specified. The injection is concentrated on the diffusion angle. As a result, light cannot be uniformly diffused over a wide angle range, and a bright display can be obtained only with a specific viewing angle.

  Thus, in the case of this embodiment, since the scattering layer 93 is arrange | positioned in the outermost surface of the viewing angle expansion film 92, it can avoid concentrating the diffusion angle of light to one. As a result, the light diffusion characteristics of the viewing angle widening film 7 can be made smoother, and a bright display can be obtained with a wide viewing angle.

FIG. 37 is a schematic configuration diagram showing an example of an apparatus for producing a viewing angle widening film.
The manufacturing apparatus 150 shown in FIG. 37 conveys the long base material 39 by roll-to-roll, and performs various processes during that time. In addition, the manufacturing apparatus 150 uses a printing method instead of the photolithography method using the above-described photomask for forming the black layer 166.

  A feeding roller 151 that feeds the base material 39 is provided at one end of the manufacturing apparatus 150, and a winding roller 152 that winds up the base material 39 is provided at the other end. The base material 39 is wound from the feeding roller 151 side. It is configured to move toward the 152 side. Above the base material 39, a printing device 153, a first drying device 154, a coating device 155, a developing device 156, and a second drying device 157 are sequentially arranged from the delivery roller 151 side to the winding roller 152 side. . An exposure device 158 is disposed below the substrate 39. The printing device 153 is for printing the black layer 166 on the base material 39. The first drying device 154 is for drying the black layer 166 formed by printing. The coating device 155 is for coating a transparent negative resist on the black layer 166. The developing device 156 is for developing the exposed transparent negative resist with a developer. The 2nd drying apparatus 157 is for drying the base material 39 in which the light-diffusion part 163 which consists of a transparent resist after image development was formed. Thereafter, the base material 39 on which the light diffusion portion 163 is formed may be bonded to the second polarizing plate 5 so that the viewing angle widening film is integrated with the polarizing plate.

  The exposure apparatus 158 is for exposing the transparent negative resist coating films 149 and 150 from the substrate 39 side. FIGS. 38A and 38B are views showing only the portion of the exposure apparatus 158 out of the manufacturing apparatus 150. FIG. As shown in FIG. 38A, the exposure apparatus 158 includes a plurality of light sources 159, and the intensity of the diffused light F from each light source 159 gradually weakens as the base material 39 advances. The intensity of the diffused light F may change. Alternatively, the exposure apparatus 158 may gradually change the emission angle of the diffused light F from each light source 159 as the base material 39 advances as shown in FIG. By using such an exposure apparatus 158, the inclination angle of the side surface of the light diffusion portion 163 can be controlled to a desired angle.

  In the above example, the liquid resist is applied when forming the black layer 166 and the light diffusion portion 163. Instead of this configuration, a film-like resist is applied to one surface of the substrate 39. Also good.

Finally, as shown in FIG. 2, the completed viewing angle widening film is disposed through the adhesive layer 8 with the base material 39 facing the viewing side and the light diffusion portion 163 facing the second polarizing plate 5. Affixed to the liquid crystal display body 6.
The liquid crystal display device of this embodiment is completed through the above steps.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the example of the light diffusing portion having a two-layer structure has been described. However, the present invention is not limited thereto, and each of the first layer, the second layer, and the third layer is made of a material having different photocuring characteristics. A three-layer light diffusion part may be provided. In this case, if the inclination angle of the side surface of each layer is made different, the diffusion angle of the light reflected from the side surface of each layer can be changed in multiple stages, and the light diffusion characteristics can be made smoother. .

  In the above embodiment, an example of a liquid crystal display device has been given as an example of a display body. However, the present invention is not limited thereto, and the present invention may be applied to an organic electroluminescence display device, a plasma display, and the like.

Moreover, although the example which adhere | attaches a viewing angle expansion film on the 2nd polarizing plate of a liquid crystal display body was shown in the said embodiment, the viewing angle expansion film and the liquid crystal display body do not necessarily need to contact.
For example, another optical film or an optical component may be inserted between the viewing angle widening film and the liquid crystal display. Or a viewing angle expansion film and a liquid crystal display body may exist in the position which left | separated. In addition, in the case of an organic electroluminescence display device, a plasma display, or the like, a polarizing plate is unnecessary, so that the viewing angle widening film and the polarizing plate do not come into contact with each other.

  Moreover, as a configuration in which at least one of an antireflection layer, a polarizing filter layer, an antistatic layer, an antiglare treatment layer, and an antifouling treatment layer is provided on the viewing side of the base material of the viewing angle widening film in the above embodiment. Also good. According to this configuration, it is possible to add a function to reduce external light reflection, a function to prevent the adhesion of dust and dirt, a function to prevent scratches, and the like according to the type of layer provided on the viewing side of the substrate. Further, it is possible to prevent deterioration of viewing angle characteristics with time.

  Moreover, in the said embodiment, although the light-diffusion part was made into the symmetrical shape on both sides of a central axis, it does not necessarily need to be a symmetrical shape. For example, when an intentionally asymmetric angular distribution is required according to the application and usage of the display device, for example, when there is a request to widen the viewing angle only on the upper side or only on the right side of the screen, light diffusion is performed. The inclination angle of the side surface of the part may be asymmetric.

  In addition, the specific configuration relating to the arrangement and shape of the light diffusing part and the light shielding layer, the dimensions and materials of each part of the viewing angle widening film, the manufacturing conditions in the manufacturing process, etc. is not limited to the above embodiment, and can be changed as appropriate. .

  The present invention is applicable to various display devices such as a liquid crystal display device, an organic electroluminescence display device, and a plasma display.

DESCRIPTION OF SYMBOLS 1,51,61,61B, 61C, 71,71B, 71C, 81,91 ... Liquid crystal display device (display device), 2 ... Backlight (light source), 4 ... Liquid crystal panel (light modulation element), 6 ... Liquid crystal display Body (display body), 7, 7A, 7B, 52, 52A, 62, 62A, 62B, 62C, 72, 72A, 72B, 72C, 92 ... viewing angle widening film (light diffusion member, viewing angle widening member), 39 ... Base material, 40, 40A, 40B, 53, 53A, 63, 63e, 63f, 63g, 63h, 63i, 63j, 63A, 63C, 73, 73A, 73B, 73C ... Light diffusion part, 40a, 40Ba, 53a, 63a, 73a: Light exit end face, 40b, 40Bb, 53b, 63b, 73b ... Light incident end face, 40c, 40Bc, 53c, 63c, 73c ... Side face, 40d, 40Bd, 53d, 63d 73d ... Interface, 41, 41A, 66, 66A, 66B, 66C, 76, 76a, 76b, 76c, 76d, 76e, 76f, 76g, 76h, 76i, 76j, 76A, 76C ... Light shielding layer, 42, 42A, 42B , 54, 54A, 64, 64A, 64C, 74, 74A, 74B, 74C ... first layer (layer made of the first material), 43, 43A, 43B, 55, 55A, 65, 65A, 65C, 75, 75A, 75B, 75C ... second layer (layer made of the second material), 49, 50 ... coating film (negative photosensitive resin layer), θ1, θ2 ... inclination angle

Claims (29)

A light-transmitting base material, a plurality of light diffusion portions formed on one surface of the base material, and a light shielding layer formed in a region other than the formation region of the light diffusion portion on one surface of the base material. Prepared,
The light diffusing portion has a light incident end surface having an area larger than the area of the light emitting end surface on the side opposite to the substrate side and having a light emitting end surface on the substrate side,
The height from the light incident end face of the light diffusion portion to the light exit end face is larger than the layer thickness of the light shielding layer,
The light diffusing member, wherein the light diffusing portion is formed of a plurality of layers of a plurality of types of incompatible materials.   The light diffusion member according to claim 1, wherein the inclination angles of the side surfaces of the plurality of layers of the light diffusion portion are different from each other.   The light diffusing member according to claim 1, wherein the refractive indexes of the materials of the plurality of layers of the light diffusing portion are different from each other.   4. The light diffusing member according to claim 1, wherein interfaces of the plurality of layers of the light diffusing portion are non-parallel to one surface of the base material. 5.   5. The light diffusing member according to claim 1, wherein an inclination angle of side surfaces of the plurality of layers of the light diffusing portion is increased as the light diffusing portion approaches the light incident end surface side.   6. The light diffusing member according to claim 1, wherein air exists in a gap between the plurality of light diffusing portions. The plurality of light diffusion portions are arranged in stripes at intervals from each other when viewed from the normal direction of one surface of the base material,
The said light shielding layer is arrange | positioned at stripe form between the light-diffusion parts arrange | positioned at the said stripe form seeing from the normal line direction of the one surface of the said base material, The one of Claim 1 thru | or 6 characterized by the above-mentioned. The light diffusion member according to one item.   8. The light diffusing member according to claim 7, wherein at least one of a dimension in a short direction of the plurality of light diffusion portions and a dimension in a short direction of the plurality of light shielding layers is set at random. The plurality of light diffusion portions are arranged in a scattered manner when viewed from the normal direction of one surface of the base material,
The light diffusing member according to claim 1, wherein the light shielding layer is continuously formed in a region other than a region where the light diffusing portion is formed.   The light diffusing member according to claim 9, wherein the plurality of light diffusing portions are regularly arranged when viewed from a normal direction of one surface of the base material.   The light diffusing member according to claim 9, wherein the plurality of light diffusing portions are aperiodically arranged when viewed from the normal direction of one surface of the base material.   The light diffusing member according to any one of claims 9 to 11, wherein the plurality of light diffusing portions have the same shape when viewed from the normal direction of one surface of the base material.   The light diffusing member according to any one of claims 9 to 11, wherein the plurality of light diffusing portions have an indefinite shape when viewed from a normal direction of one surface of the base material.   14. The planar shape of the light diffusing portion viewed from the normal direction of one surface of the substrate is a circle, an ellipse, or a polygon. 15. Light diffusing member.   The light diffusing member according to any one of claims 1 to 14, wherein the substrate has light diffusibility. A light-transmitting base material, a plurality of light-shielding layers formed on one surface of the base material, and a light diffusion portion formed in a region other than the light-shielding layer forming region on one surface of the base material. ,
The light diffusing portion has a light incident end surface having an area larger than the area of the light emitting end surface on the side opposite to the substrate side and having a light emitting end surface on the substrate side,
The height from the light incident end face of the light diffusion portion to the light exit end face is larger than the layer thickness of the light shielding layer,
The light diffusing member, wherein the light diffusing portion is formed of a plurality of layers of a plurality of types of incompatible materials.   The plurality of light shielding layers are arranged in a scattered manner when viewed from the normal direction of one surface of the base material, and the light diffusion portion is continuously formed in a region other than the region where the light shielding layer is formed. The light diffusing member according to claim 16.   The light diffusing member according to claim 17, wherein the plurality of light shielding layers are regularly arranged as viewed from a normal direction of one surface of the base material.   The light diffusing member according to claim 17, wherein the plurality of light shielding layers are disposed aperiodically when viewed from a normal direction of one surface of the base material.   20. The light diffusing member according to claim 16, wherein the plurality of light shielding layers have the same shape as viewed from the normal direction of one surface of the base material.   The light diffusing member according to any one of claims 16 to 19, wherein the plurality of light shielding layers have an indeterminate shape when viewed from a normal direction of one surface of the base material.   The light according to any one of claims 16 to 21, wherein a planar shape of the light shielding layer viewed from the normal direction of one surface of the substrate is a circle, an ellipse, or a polygon. Diffusion member. Forming a light-shielding layer having an opening on one surface of a light-transmitting substrate;
Adjusting a negative photosensitive resin material in which a plurality of materials that are incompatible with each other are mixed; and
Placing the negative photosensitive resin material on one surface of the substrate so as to cover the light shielding layer;
Phase-separating the negative photosensitive resin material to form a plurality of negative photosensitive resin layers separated in the normal direction of one surface of the substrate;
Exposing the plurality of negative photosensitive resin layers through an opening of the light shielding layer from a surface opposite to one surface of the base material on which the light shielding layer and the plurality of negative photosensitive resin layers are formed;
Developing the plurality of the negative photosensitive resin layers after the exposure, and having a light emission end face on the substrate side and having a light incident area larger than the area of the light emission end face on the side opposite to the substrate side Forming a plurality of light diffusion portions having end faces on one surface of the substrate;
A method for producing a light diffusing member.   24. The method of manufacturing a light diffusing member according to claim 23, wherein any one of black resin, black ink, metal alone, or a multilayer film of a metal simple substance and a metal oxide is used as the material of the light shielding layer. . A display body, provided on the viewing side of the display body, and a viewing angle widening member that emits light in a state where the angular distribution of light incident from the display body is wider than before incidence, and
23. A display device, wherein the viewing angle enlarging member comprises the light diffusing member according to any one of claims 1 to 22. The display body has a plurality of pixels forming a display image,
26. The display device according to claim 25, wherein a maximum pitch between adjacent light diffusion portions among the plurality of light diffusion portions of the light diffusion member is smaller than a pitch between the pixels of the display body. . The display body includes a light source and a light modulation element that modulates light from the light source,
27. The display device according to claim 25, wherein the light source emits light having directivity. An adhesive layer is provided between the display body and the light diffusing member,
28. The display device according to claim 25, wherein the adhesive layer has light diffusibility.   29. A display device according to claim 25, wherein the display body is a liquid crystal display element.

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