JP2003075644A - Hologram reflector, reflection type liquid crystal display device mounted with the reflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hologram reflector which can control the direction or the view range where the display light can be clearly observed and to provide a reflection type liquid crystal display device mounted with the reflector. SOLUTION: In the hologram reflector having a light reflecting layer formed with an adhesive layer on one surface of a volume phase type hologram layer, one or both faces of the hologram layer or the reflective surface of the reflecting layer or one or both faces of the adhesive layer have a fine rugged pattern. The hologram reflector is mounted in the reflection type liquid crystal display device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a hologram reflector which can control a direction and a viewing range where display light is bright and visible by using a hologram. The technical field in which a hologram reflector is used is a reflective liquid crystal display device that does not require a special light source such as a backlight or an edge light and uses reflected light from ambient light (sunlight or indoor lighting) as display light. Typical applications include watches and mobile phones.

[0002]

2. Description of the Related Art A reflection type liquid crystal display device of a type having a light reflection layer on the back surface of a liquid crystal panel (on the side opposite to an observer) and using reflected light from ambient light (sunlight or indoor lighting) as display light is conventionally known. Attempts have been made to use holograms as reflective layers instead of the metallic reflective layers of

In the conventional metal reflection layer, the intensity of the reflected light is the highest in the direction of specular reflection of the incident light, so that the direction in which the glare appears due to the reflection of the illumination light (due to the cover glass on the surface of the device) and the display. There is a problem that the directions in which the reflected light from the device becomes brightest overlap. The use of the hologram realizes the control of the viewing area, and it is possible to achieve a bright display in a specific direction as compared with the conventional metal reflective layer.

A reflection type liquid crystal display device using a hologram as a reflection plate is described in the following patent publications. (1) JP-A-56-51772 (2) JP-A-8-505716 (3) JP-A-9-152586 (4) JP-A-9-222512 (5) International Publication 96 / 37805

There are various types of holograms, and the characteristics of the hologram reflector also change accordingly. JP-A-5
In the case of the surface relief hologram reflection plate described in Japanese Patent Publication No. 6-51772, since it is difficult to increase the diffraction efficiency, it is difficult to visually recognize a bright display pattern, and the hologram is observed due to the color dispersion of the hologram. There is a problem that the visible color changes depending on the direction of movement.

In the case of the volume phase transmission hologram disclosed in Japanese Patent Laid-Open No. 9-222512 or International Publication No. 1996/37805, since it has a wide diffraction wavelength width over the visible wavelength range, a bright display pattern by white reflected light is provided. When a hologram reflection plate using a volume phase transmission hologram is applied to a display device, white display light is realized, so use a color filter in the display device together. Therefore, it is suitable for displaying a full-color image.

Although a full-color display image is not required, it is desirable to give a special hue to the display light in order to have an interesting visual effect (eye catching effect) even with a monochrome display pattern. In some cases, it exists depending on the application.

In the case of the reflection plate of the volume phase reflection type hologram disclosed in JP-A-8-505716 or JP-A-9-152586, the wavelength width reflected and diffracted by the wavelength selectivity is limited ( Will be a specific color)
There is a problem that it is difficult to visually recognize a bright display pattern in the visible wavelength range.

A hologram reflection plate using a volume phase reflection type hologram has a specific wavelength (generally,
(Green) display light is realized, but the diffraction wavelength of the hologram is determined according to the combination of the photosensitive material and the laser light used for shooting, so it is not possible to create products that reflect at any wavelength (color). However, from the aspect of hologram design and manufacturing equipment, there is a problem that the manufacturing cost increases.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and is equipped with a hologram reflection plate and its reflection plate capable of controlling the direction in which the display light can be viewed brightly and the viewing range. An object of the present invention is to provide a reflective liquid crystal display device.

[0011]

In order to achieve the above object, the invention according to claim 1 is a hologram reflection plate having a light reflection layer formed on one surface of a volume phase hologram layer via an adhesive layer. 2. In the hologram reflection plate, one surface or both surfaces of the hologram layer has a fine concavo-convex pattern.

According to a second aspect of the present invention, in a hologram reflection plate having a light reflection layer formed on one surface of a volume phase hologram layer via an adhesive layer, the surface of the reflection layer on the reflection surface side has fine irregularities. A hologram reflector having a pattern.

According to a third aspect of the present invention, there is provided a hologram reflection plate in which a light reflection layer is formed on one surface of a volume phase hologram layer via an adhesive layer, and one surface or both surfaces of the adhesive layer has a fine concavo-convex pattern. It is a hologram reflection plate characterized by having.

According to a fourth aspect of the present invention, in the hologram reflection plate according to any one of the first to third aspects, the fine concavo-convex pattern has a lenticular shape or a Fresnel lens shape.

According to a fifth aspect of the present invention, a polarizing film is laminated on the back surface side of the liquid crystal panel on the surface of the hologram layer of the hologram reflection plate according to any one of the first to fourth aspects.
A liquid crystal display device is formed by laminating a liquid crystal panel on the polarizing film side.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing an example of a hologram reflector of the present invention and a reflective liquid crystal display device using the reflector. 2-11
FIG. 4 is a cross-sectional view listing the configuration of a hologram reflection plate of the present invention. FIG. 3 is a sectional view showing an example of a conventional hologram reflection plate.

As shown in FIG. 1 (a), the present invention uses a hologram in a reflection type liquid crystal display device, and the hologram reflection plate in the present invention has a direction / viewing range in which display light can be viewed brightly. In order to control the above, a fine concavo-convex pattern is formed on one surface or both surfaces of the hologram layer surface constituting the hologram reflection plate. Alternatively, FIG.
As shown in Nos. 11 to 11, the surface of the reflective layer on the reflecting surface side is formed with a fine uneven pattern, or one or both surfaces of the adhesive layer surface is formed with a fine uneven pattern.

The hologram layer constituting the hologram reflection plate of the present invention can be used in combination with a coating method in which a film having various shapes is coated on a support on which a photosensitive material is coated to form photosensitive materials having various surface shapes. It becomes possible to manufacture. For example, using a base material having a different haze value as a base material, a fine pattern is previously formed on the base material itself or on the base material with a UV resin or the like, and a smooth photosensitive material coated surface is formed on the base material by a gap method. You can list them.

The reflection layer constituting the hologram reflection plate of the present invention is often composed of a base material and a reflection layer. The substrate may be either light scattering or highly transparent, but a sheet-processable plastic film having excellent smoothness is used. Especially, a polyester film is preferably used. As polyester film, Toray Lumirror S10, Lumirror T60, Melinex 77
0, Toyobo A4100, A4300, Teijin HS
Type, diamond foil O type, etc. In addition to these, there are polyolefin and polystyrene films. When providing the concavo-convex pattern on the substrate, a fine concavo-convex pattern can be formed at the time of sheet extrusion, hot press molding, or using UV resin. It is also possible to form a pattern by printing or the like. A reflective layer is formed by vapor-depositing aluminum, silver, chromium, nickel or the like on the surface of the fine concavo-convex pattern, or by coating an ink containing a reflective filler.

As the adhesive layer constituting the hologram reflection plate of the present invention, an adhesive, a UV adhesive or an adhesive for dry laminating can be used. Generally, an adhesive is often used, and it is easy to arbitrarily set the shape of the adhesive for joining the constituent members. The shape can be set according to the shape of the hologram photosensitive material. During lamination, the hologram layer and the reflection layer are flexibly embedded in the concavo-convex pattern to form an inverted shape. The thinner the thickness, the brighter it becomes, while the thicker the field of view, the darker it becomes. In addition, UV bonding or thermosetting bonding is also used because it absorbs irregularities of a hard film of a hologram layer or a reflective layer and is easily deformed, so that the shape is deformed and bubbles and the like are less likely to be included.

The fine concavo-convex pattern may have a lenticular shape or a Fresnel lens shape.

The volume phase hologram used in the present invention can be photographed and recorded on the photosensitive material for volume phase hologram by using an ordinary two-beam hologram photographing optical system. Examples of the light-sensitive material include gelatin dichromate, silver salt light-sensitive material, and photopolymer. As an example, a silver salt photosensitive material 8E56 film for hologram manufactured by AGFA or HRF600 manufactured by DuPont can be used.

In the recording and recording of holograms, a well-known recording and recording method is used, and a diffusion plate (frosted glass) is used as a subject.
Image recording is performed on the above-mentioned various light-sensitive materials. In order to obtain white diffracted light, if the light-sensitive material is a silver salt, CWC2
After developing with a developing solution, bleaching with a PBQ2 bleaching solution, washing with water and drying, and in the case of HUF600 manufactured by DuPont, after heat development, bleaching with ultraviolet rays is carried out. Obtain a volume phase hologram.

The hologram reflector of the present invention can be used as a liquid crystal display device by laminating a polarizing film on the back side of a liquid crystal panel, on the surface of a hologram layer, and laminating it on the polarizing film side with a liquid crystal panel.

In the reflection type liquid crystal display device using the hologram reflection plate of the present invention, as shown in FIG. 1 (b), a smooth reflection film A has a metal vapor deposition which becomes the light reflection layer 8 on one surface of the base material 10. This is a structure in which layers are formed. The hologram reflection plate B has a structure in which the volume phase hologram layer 6 and the polarizing plate 4 are further laminated on the reflection film A, and the liquid crystal panel 2 is provided.
Placed on the back of. The reflection film A and the polarizing plate 4 are bonded and integrated with the hologram layer 6 via the adhesive 9.

Polarizing plates 3 and 4 are arranged on the front and back of the liquid crystal panel 2, respectively. When the ambient light that becomes the illumination light 11 enters the liquid crystal display device, first, only the light of the polarization component in one direction reaches the liquid crystal panel 2 by the first polarizing plate 3, and the liquid crystal panel 2 responds to the display pattern according to the display pattern. After being rotated, it reaches the second polarizing plate 4.

The light transmitted through the second polarizing plate 4 is incident on the volume phase hologram layer 6, and this hologram layer 6
Has an angle selectivity, and the incident light is transmitted without being diffracted by the hologram layer 6 depending on the angle selectivity of the hologram layer 6.

The light 7 transmitted through the hologram layer 6 reaches the light reflection layer 8 formed on the back surface of the hologram layer 6, is specularly reflected, and enters the hologram layer 6 again.

The incident light 12 at this time is the first incident light 7
Is incident on the hologram 6 at an angle of incidence opposite to that of positive and negative, but this coincides with the angle selectivity of the hologram layer 6, and this time it is diffracted and emitted as diffracted light 13 at a specific angle. The diffracted light 13 again passes through the polarizing film 4, the liquid crystal panel 2 and the polarizing film 3 and reaches the eyes 14 of the observer as pattern display light.

In the present invention, at the stage of producing a hologram photosensitive material, a pattern is previously formed on the base material with a UV resin or the like, and the pattern is applied thereto by a known application method such as knife coating, whereby the UV pattern is formed. The concavo-convex of the reverse shape is formed. Since this is photographed, refraction is added to the light diffraction, and it is possible to write pictures and characters with a strong taste. The regular arrangement of refraction and diffraction, such as a lenticular lens, a Fresnel lens, and a prism lens, can improve the brightness and the field of view.

Here, in the present invention, among the above explanations, the hologram layer, the adhesive layer, and the reflective layer form various irregularities, so that various optical designs can be made based on the difference in refractive index. Specifically, if a lenticular land, a Fresnel lens, and a prism lens are formed in this, it is possible to expand the field of view and collect light. Furthermore, by incorporating irregularities in the pattern and characters, it is possible to provide more reflectors that match the taste.

[0032]

EXAMPLES Examples of the present invention will be specifically described below.

<Example 1> (corresponding to claims 2 and 3) Polyester film (manufactured by Toyobo, A4100; 25μ)
(Thickness) as a base material, and a fine pattern is formed using a stamper subjected to electroless nickel plating treatment with a urethane acrylate UV resin. A on this pattern formation surface
l was vapor-deposited (150 Å thickness) to form a light reflection layer.

Next, the argon ion laser (514.5) is recorded by the two-step photographing and recording method as described above.
nm) was used to coat a PET film with a film material of a transparent hologram recording material, and exposure recording was performed at 15 μm to form a hologram.

SK Dyne 2092 + AX as an adhesive
(Crosslinking agent) was prepared to have a viscosity of about 200 cps, coated on a substrate silicone-treated PET (heavy release) with a lip coater, and laminated with silicone-treated PET (light release). The thickness at this time was 10 to 25 μm. By using this adhesive material, the reflection layer and the hologram layer are attached to each other, whereby irregularities having a shape opposite to that of the reflection layer are formed.

On the hologram of this hologram reflector,
A polarizing plate for TN liquid crystal (manufactured by Nitto Co., Ltd.) was attached to obtain a hologram reflection plate having a structure shown in FIG. Among them, FIG. 7 shows the case of the Fresnel lens shape, FIG. 8 shows the case of the lenticular lens, and FIG. 9 shows the case of the prism lens.
Respectively shown.

The polarizing plate side of the hologram reflection plate is arranged so as to face the liquid crystal panel, and the hologram reflection plate is laminated via an adhesive layer,
The reflective liquid crystal display device having the structure shown in FIG. 1 was used.

<Example 2> (corresponding to claims 1 and 3) Unlike Example 1, Al vapor deposition (15
0 Å) was applied to form a light reflection layer. Next, unlike in Example 1, a hologram layer was formed with a fine concave-convex pattern on the Al vapor-deposited layer. A reflective layer and a hologram layer were attached and processed with the same adhesive material as in Example 1 to fabricate a reflective plate having an irregular shape of the adhesive material opposite to that of the hologram layer.

On the hologram of this hologram reflector,
A polarizing plate for TN liquid crystal (manufactured by Nitto) was attached to obtain a hologram reflector. Here, FIG. 2 shows a case where the one-sided hologram is uneven. FIG. 3 shows the case where the both sides have unevenness, FIG. 4 shows the case where the reflection side Fresnel lens is the polarizing plate side lenticular lens, and FIG. 10 shows the case where the one side hologram is the prism lens.

The polarizing plate side of the hologram reflection plate is arranged so as to face the liquid crystal panel, and the hologram reflection plate is laminated via an adhesive layer,
The reflection type liquid crystal display device having the structure shown in FIG.

<Example 3> (corresponding to claim 4) By combining Examples 1 and 2, the hologram layer, the reflection layer, and the adhesive layer all form fine irregularities, and Fresnel as shown in Figs. It is possible to combine lenses and lenticular lenses.

<Comparative example> Although the basic structure is the same as that of the embodiment,
FIG. 12 shows a hologram reflection plate in which all of the hologram layer, the reflection layer, and the adhesive layer are bonded together with smooth surfaces.
Further, the polarizing plate for TN liquid crystal (manufactured by Nitto) is arranged so as to face the liquid crystal panel, and is laminated via an adhesive layer, as shown in FIG.
The liquid crystal display device shown in FIG.

[0043]

Industrial Applicability The present invention provides a hologram reflector which can control the direction and viewing range in which the display light can be viewed brightly by using a hologram, and a reflection type liquid crystal display device equipped with the hologram reflector. You can Various combinations such as a wider viewing area, a three-dimensional pattern, and a color tone are possible by combining the concave and convex patterns of the reflection layer, the hologram layer, and the adhesive layer of the hologram reflection plate having the same hologram as a constituent element.

[0044]

[Brief description of drawings]

FIG. 1A is a cross-sectional view showing an example of the configuration of a hologram reflection plate of the present invention. 9B is a schematic sectional view showing an example of a reflective liquid crystal display device using the hologram reflector shown in FIG.

FIG. 2 is a cross-sectional view showing a configuration of a hologram reflection plate of the present invention having an uneven pattern on a reflection plate side hologram layer and an adhesive layer.

FIG. 3 is a cross-sectional view showing a configuration of a hologram reflection plate of the present invention in which both the hologram layers on both sides and the adhesive layers on both sides have uneven patterns.

FIG. 4 is a cross-sectional view showing a configuration of a hologram reflection plate of the present invention in which the concavo-convex pattern of the hologram reflection plate shown in FIG. 3 is a Fresnel lens on the reflection side and a lenticular lens on the polarization plate side.

FIG. 5 is a cross-sectional view showing the configuration of a hologram reflection plate of the present invention having a concavo-convex pattern on a reflection layer and an adhesive layer on the reflection side.

FIG. 6 is a cross-sectional view showing a configuration of a hologram reflection plate of the present invention in which a reflection layer has a concavo-convex pattern formed of Fresnel lenses.

FIG. 7 is a cross-sectional view showing a configuration of a hologram reflection plate of the present invention in which a reflection layer has an uneven pattern made of a lenticular lens.

FIG. 8 is a cross-sectional view showing the configuration of a hologram reflection plate of the present invention having a concavo-convex pattern in which the reflection layer is a prism lens.

FIG. 9 is a cross-sectional view showing a configuration of a hologram reflection plate of the present invention in which a reflection layer has a Fresnel lens, a hologram layer has a lenticular lens, and an adhesive layer between the hologram layer and the reflection layer has an uneven pattern corresponding to this. .

FIG. 10 is a cross-sectional view showing a configuration of a hologram reflection plate of the present invention in which the concave-convex pattern of the hologram reflection plate shown in FIG. 1A has a prism shape.

FIG. 11 is a cross-sectional view showing a configuration of a hologram reflection plate of the present invention having a concavo-convex pattern in which a reflection layer is a Fresnel lens and a polarizing layer side of the hologram layer is a lenticular lens.

FIG. 12 is a sectional view showing an example of a conventional hologram reflection plate.

[Explanation of symbols]

A ... Reflective film B ... Hologram reflector 2 ... Liquid crystal panel 3 ... Polarizing plate 4 ... Polarizing plate 6 ... Hologram layer 8 ... Light reflection layer 9 ... Adhesive layer 10 ... Base material

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03H 1/04 G03H 1/04 F term (reference) 2H042 BA01 BA04 BA12 BA15 BA20 DA02 DA03 DA04 DA11 DC02 DC04 DD09 DE04 2H049 CA05 CA09 CA11 CA16 CA28 2H091 FA02Y FA08X FA08Z FA19Y FA27Y FD08 LA16 2K008 AA10 DD15 EE04 EE07 FF17 HH01 HH23

Claims (5)

[Claims] 1. A hologram reflection plate having a light reflection layer formed on one surface of a volume phase hologram layer via an adhesive layer, wherein one or both surfaces of the hologram layer has a fine uneven pattern. Hologram reflector to do. 2. A hologram reflection plate in which a light reflection layer is formed on one surface of a volume phase hologram layer via an adhesive layer, wherein a surface of the reflection layer on the reflection surface side has a fine concavo-convex pattern. And a hologram reflector. 3. A hologram reflection plate in which a light reflection layer is formed on one surface of a volume phase hologram layer via an adhesive layer, wherein one surface or both surfaces of the adhesive layer has a fine uneven pattern. Hologram reflector. 4. The hologram reflection plate according to claim 1, wherein the fine concavo-convex pattern has a lenticular shape or a Fresnel lens shape. 5. A polarizing film is laminated on the back side of the liquid crystal panel, on the surface of the hologram layer of the hologram reflection plate according to claim 1, and is laminated on the polarizing film side with the liquid crystal panel. Liquid crystal display device.