JP2003337209A - Diffusing reflector and its application - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive diffusing reflector having excellent luminance and durability because the plate diffuses and reflects any oblique incident light while imparting directivity to the front direction to the light. <P>SOLUTION: The diffusing reflector reflects light to uniformly diffuse or condense the light in an objective range. The reflector uses a surface relief type grating and a surface relief type hologram diffusing body. The diffusing reflector having such scattering characteristics that the scattered light shows an illumination pattern and the scattering intensity is made uniform in the pattern is obtained by laminating holograms having diffusion characteristics different from a hologram diffusing body for controlling an illumination pattern and a grating for controlling the scattering intensity in the illumination pattern. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hologram diffuse reflector, and more particularly to a diffuse reflector used as a diffuser for controlling scattered light in a specific angle range, a reflective liquid crystal display device using the diffuse reflector, and an illumination device. And a member for optical communication.

[0002]

2. Description of the Related Art The characteristics required for a diffuser of a reflective LCD, which is an example of a diffuse reflector, are such that even obliquely incident light is efficiently reflected to the front, the area is wide, and the seam is invisible. It is durable and has low material cost. Conventionally, for example, in the reflection plate of Japanese Patent Laid-Open No. 2000-105317, the relief type hologram diffuser and the volume phase type hologram are combined and reflected to the front with respect to these requirements. As a device relating to a reflective liquid crystal display device using a surface relief hologram as a member, (1) JP-A-56-51772, (2) JP-A-8-505716, (3) JP-A-9- No. 152852, (4) JP-A-9-222
512, (5) JP-A-11-84372,
(6) There is JP-A-2000-105317. In both cases, the intensity of the reflected light seen from the front is increased by using the diffuser for the diffuse reflector.

By utilizing these techniques, it is possible to obtain an image with high contrast and brightness on the reflection type LCD diffusion plate. However, (1) above,
In the methods according to the publications (2), (4) and (5), the relief type hologram diffuser has a low scattering angle selectivity, and therefore the reflection angle is too wide. Further, in the publication (3), the incident direction is considered only in a specific direction, so that it is difficult to use in the case of indoor illumination in which illumination light is incident from various angles. In order to control diffusion in the vertical and horizontal directions, it is desirable to use a diffraction grating having grooves in a grid pattern and different pitches in the vertical and horizontal directions, or to use a diffuser having an anisotropic speckle pattern. In fact, the method (6) uses a diffuser having an anisotropic speckle pattern. However, since the volume hologram is used as the diffraction grating, the durability is poor, and since the diffraction grating is placed in front of the diffuser from the observer's point of view, the light reflected by the diffraction grating surface is spectrally separated. Color unevenness and bleeding easily occur.

[0004]

DISCLOSURE OF THE INVENTION In the case of a diffuse reflector, the present invention provides a diffuse reflector having excellent brightness by diffusing and reflecting any obliquely incident light with directivity in the front direction. It is another object of the present invention to provide a diffuse reflector having excellent durability and low cost.

[0005]

SUMMARY OF THE INVENTION The present invention uses a diffuse reflection plate in which a surface relief type diffraction grating and a surface relief type hologram diffuser having directivity for diffusion are combined.

The present invention (1) is a diffuse reflector for reflecting light and diffusing or condensing the light uniformly within a target range, which is a surface relief type diffraction grating and a surface relief type hologram diffusion. It is a diffuse reflector characterized by using a body. (2) In the surface relief type diffraction grating or the surface relief type hologram diffuser of the diffuse reflection plate, one surface having a groove for reflecting light is covered with a metal film or a dielectric material having a refractive index of 1.6 or more. The diffuse reflector according to (1) above. As the metal film, for example, a film formed by sputtering Ag or Al and a metal containing them as a main component can be used. As the dielectric, for example, TiO ₂ or ZrO ₂ can be used. (3) The diffuse reflection plate according to (1) or (2) above, which uses a reflective surface relief type diffraction grating and a transmissive surface relief hologram diffuser. (4) When 10 mW of laser light in the visible wavelength range is reflected by a diffuser on the xy plane, | S | = 1
Is a unit direction vector S (Sx, Sy, S of incident light)
z), certain variables θ1 and θ2 (7 ° <θ1 or θ2 <40 °) exist, and the range of the incident angle Sx of the laser is | Sx | <sin (θ1) and the range of the incident angle Sy. Is arbitrarily changed with | Sy | <sin (θ2), and when the reflected light in the direction perpendicular to the diffuser is observed, 40% of the incident light has the same solid angle range A as the incident angle range.
Light intensity when uniformly scattered in (sr) 2.7 / A
The diffuse reflection plate according to any one of (1) to (3) above, which is always stronger than (cd). (5) As a characteristic of the surface relief hologram diffuser used as a member of the diffuse reflector, when the direction vector of the incident light is S _i (0,0,1), certain variables θ1, θ2
(4 ° <θ1 <35 °; 90 °>θ2> θ1 × 1.5) exists and the unit direction vector S of transmitted light or reflected light
For (Sx, Sy, Sz), | Sx | <sin (θ
1) And 90% or more of the incident light is transmitted or reflected in the angle range of | Sy | <sin (θ2), and the peak half value width θ1w of the angular distribution of transmitted or reflected light intensity in the X-axis direction is 3 ° < The diffuse reflection plate according to any one of (1) to (4) above, which uses a surface relief hologram diffuser with θ1w <20 °. Also,
(6) As a characteristic of the surface relief type diffraction grating used as the member of the diffuse reflector, the direction vector of the incident light is S
_{When i} (0, 0, 1), certain variables θ1, θ2 (4 °
<Θ1 <35 °; 90 °>θ2> θ1 × 1.5) exists, and | Sx | <sin (θ1) and | Sy | <for the unit direction vector S (Sx, Sy, Sz) of scattered light si
The diffuse reflection plate according to any one of (1) to (4) above, which uses a surface relief type diffraction grating, in which 90% or more of incident light enters in an angle range of n (θ2).

The above (1), (4), (5) and (6)
Then, in the diffuse reflection plate, by combining a diffraction grating and a directional diffuser, light incident in a certain angle range is diffusely reflected in the front direction. The diffraction grating used for the diffuse reflector and the diffuser may be spatially closely attached or separated. The target range of (1) refers to a range of an illumination pattern such as a square or an ellipse. Here, the diffraction grating is a film or a plate that can reflect incident light in a direction other than the regular reflection direction and has a large number of elongated grooves at equal or unequal intervals in a region of a size in which the diffraction effect is remarkable. Is. Further, the hologram diffuser is a film or plate in which grooves and holes are randomly arranged in a region having a size in which the diffraction effect is remarkable. Further, here, the diffraction efficiency η of the diffuser is defined as follows. Diffraction efficiency η = (total reflected light amount-amount of light specularly reflected without being diffracted) / total reflected light amount

As in the case of (2), the diffuse reflection film may be formed only by covering with a metal film or a dielectric material having a high refractive index. The metal reflection film is most preferably provided on the diffraction grating in order to direct the reflected light in the aimed direction.

With the configuration (3), the light once diffused by the hologram diffuser is scattered by the diffraction grating, so that moire and display unevenness due to the reflected light on the hologram surface can be eliminated.

The present invention also provides (7) a diffuse reflection plate as described in any one of (1) to (6) above, characterized in that a surface relief type diffraction grating and a surface relief type hologram diffuser are laminated. Is. (8) The diffuse reflection plate according to any one of (1) to (6) above, wherein the surface relief type diffraction grating and the surface relief type hologram diffuser are formed on both front and back surfaces.

With the constructions (7) and (8),
A diffuse reflector having both the characteristics of the diffuser and the diffraction grating can be easily obtained.

Further, the present invention (9) is characterized in that the surface relief type diffraction grating and the surface relief type hologram diffuser are formed on the same surface.
The diffuse reflector according to any one of 1. In (9), by making the size of the unevenness of the diffuser larger than the groove period of the diffraction grating, or conversely, by making the groove period of the diffraction grating larger than the size of the unevenness of the diffuser, the same surface is formed. The purpose is to reduce the number of transfer processes by overwriting two shapes so that only one side is formed. As a method of stacking, it is better to completely separate the diffuser layer and the diffraction grating layer. That is, when the holes of the diffuser are larger than the pitch of the diffraction grating, the grooves of the diffuser are dug up to a depth of 0.5λ, and the diffraction grating from the depth of 0.5λ to λ is formed only where the grooves of the diffuser are carved. Dig the ditch. When designed in this way, the diffraction efficiency of the diffraction grating is reduced, but the present invention does not necessarily require high diffraction efficiency. Here, λ is the center wavelength of visible light used.

Further, according to the present invention, (10) an angle range of scattered light obtained by exposing a photosensitive material with a laser through a mask diffuser hole consisting of a hole for making an illumination pattern and a diffuser and making unevenness The diffuse reflection plate according to any one of (1) to (9) above, wherein a controlled surface relief hologram diffuser is used. Above (1
As described in 0), the hologram diffuser manufactured by exposing through the mask diffuser hole can control the diffusion angle of the diffused light. Japanese Unexamined Patent Publication No. 4-299303 describes a method of forming a diffuser for a volume phase hologram, but the exposure principle is the same. The surface relief hologram obtained by exposure and development may be used as it is or transferred.

Further, according to the present invention, there is provided (11) any one of the above (1) to (10), wherein the surface relief type diffraction gratings are laminated so that the directions of the grating grooves are non-parallel. It is a diffuse reflector. (12) In any one of the above (1) to (10), the grating grooves of the surface relief type diffraction grating are arranged vertically and horizontally on the same surface or the front and back surfaces so as to be non-parallel. It is the diffuse reflection plate described. In the hologram diffuser, the above (11),
By combining the diffraction grating as in (12), the scattering intensity in the illumination pattern can be made uniform.

The present invention also provides (13) the diffusion according to any one of the above items (9) to (12), characterized in that the laminated layers of the surface relief type hologram diffusers are adhered via an adhesive layer. It is a reflector. Further, (14) the diffused reflection plate according to any one of the above (9) to (12), wherein the layered surface relief hologram diffuser is sandwiched by spacers. The surface relief type holograms can be easily laminated by the above-mentioned steps (13) and (14).

(15) The present invention (15) is characterized in that the surface relief hologram diffuser is obtained by transferring the surface relief hologram from a mold such as an electroforming mold of a transfer roll. ) Is a diffuse reflection plate. (16) The surface relief hologram diffuser uses a UV curable resin as a material for the surface relief hologram.
It is the diffuse reflection plate described in 5). (17) The surface relief hologram diffuser is the diffuse reflector described in (15), characterized in that a thermoplastic resin is used as a material of the surface relief hologram. Above (1
As in 5), (16) and (17), it can be manufactured at low cost by transferring from a mold such as a master electroforming mold of a diffuser or a diffraction grating to a UV curable resin or a thermoplastic resin.

The present invention also provides (18) a reflective liquid crystal display device using the diffuse reflection plate according to any one of (1) to (17) above as a diffusion reflection plate. Also,
(19) A member for lighting equipment, which uses the diffuse reflection plate according to any one of (1) to (17) as a diffusion reflection plate. (20) An optical communication member using the diffuse reflection plate according to any one of (1) to (17) above as a diffusion reflection plate. Above (18), (1
As described in 9) and (20), it can be used as a liquid crystal display device, a lighting device, and a member for optical communication. By incorporating it in a reflective liquid crystal display device, it becomes easy to control the scattering direction and bright display is possible. Further, if a diffraction grating having a metal film deposited thereon is used, it can be expected that a display device can be manufactured without a polarizing plate by utilizing the polarization characteristic of the reflected light of the diffraction grating. In addition to the reflective liquid crystal display device, the diffuse reflector can be used as a diffuser for a projector screen and a diffuser for laser beam shaping. Lighting applications include camera flash and room lighting. Further, examples of optical communication applications include a diffuser of an optical sheet bus and shaping of a light intensity distribution of an optical fiber signal.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a diffuse reflection plate in which surface relief holograms are laminated. Here, a diffuse reflection plate in which films are laminated is used. In the case of reflection type illumination using reflection, the light passing through the surface relief type hologram diffuser 12 as shown in FIG. 1 is shaped and diffused into an ellipse or a rectangle. Next, the light intensity distribution becomes uniform at the surface relief type diffraction gratings 14 and 16. Further, the reflection in the metal film 18 increases the brightness in the front direction. Once again, it is shaped by the surface relief type hologram diffuser 12, and finally, uniform illumination light is obtained. At this time, the diffraction efficiency of the surface relief hologram diffuser alone is 70% or more and the diffusion angle is ± 15.
Those below ° are preferred. The surface relief hologram diffuser and the surface relief diffraction grating may be laminated so that the concavities and convexities face each other. For surface relief type diffraction grating, it is preferable to have grid grooves in a grid pattern on one film to reduce light loss, rather than stacking two films with different grating groove directions. It is preferable to directly attach to the grating groove of the diffraction grating so as to have directivity to the front. It is preferable that the material of the diffuser and the adhesive have an extinction coefficient of 1 μm ⁻¹ or less for light having a wavelength of 633 nm, a cure shrinkage of 3% or less and a birefringence of 30 nm or less during hologram molding. In order to diffuse the light on the diffuser surface,
When the wavelength is λ and the refractive index of the member of the diffuser is n, the uneven depth of the diffuser is preferably λ / (n-1) or more. When the light of the diffuser is reflected by the diffraction grating surface and condensed,
The diffraction grating has an uneven shape similar to a Fresnel lens,
The depth is mλ /, where λ is the wavelength and θ is the incident angle.
(2cos θ), m = 1, 2, 3, ... (± 10
% Or less) is desirable. When the light of the diffuser is reflected by the diffraction grating surface and diffused uniformly, the depth is (m-
0.5) · λ / (2cosθ), m = 1, 2, 3, ...
It is desirable to be in the vicinity of (within ± 10%).

FIG. 2 shows a method for measuring the scattering angle of a diffuse reflection plate of reflection by a luminance meter. Scattering angles θ1 and θ2 are defined using a Cartesian coordinate system, and a method for measuring scattered light is shown. The diffuse reflector is on the xy plane, and the incident light is scattered in the + Z axis direction. The direction of the scattered light is the unit vector S (S
x, Sy, Sz). At this time, -sin ([theta] 1) <Sx <sin ([theta] 1) and -sin shown by hatching in the figure.
Incident light is scattered in the range of (θ2) <Sy <sin (θ2). The reflection characteristics were measured from the front by a luminance meter.

An apparatus for producing the laminated film member
An example of the exposure optical system and its members is shown in FIGS. A desired electroforming mold is used as a mold of the transfer roll 34 as shown in FIG. 3, and after transferring to a UV curable resin, it is exposed to UV. In the case of a diffraction grating embossed in this way, the result is as shown in FIG.

Next, the stacking method will be described with reference to FIG. As shown in FIG. 5A, the UV curable resin 40 is placed on the transparent resin film 42. Figure 5 with embossing
A diffraction grating as shown in (b) is formed and UV cured. Then, if necessary, it is covered with a metal film or a dielectric having a refractive index of 1.6 or more. Next, as shown in FIG. 5C, the adhesive 44, the transparent resin film 42 and the UV curable resin 40 are placed and laminated. Further, a surface relief type hologram diffuser as shown in FIG. 5D is formed by embossing and UV cured. Here, the material of the transparent resin film is preferably PMMA (polymethylmethacrylate) or alicyclic acrylic resin.

If necessary, a diffuser may be formed as a member on the microlens array or the cylindrical lens array as described in claim 10.

In the present invention, the surface relief type diffuse reflection plate is used as a member, but in principle, a volume phase type can be similarly manufactured. For example, in the case of a reflection type diffuse reflector, if the metal reflection film, the volume phase type diffraction grating diffuser, and the surface relief type diffuser are arranged in this order, the brightness becomes higher due to the excellent angle selectivity of the volume phase type diffraction grating. it can.

A surface relief type hologram diffuser or the like is prepared by producing an electroforming mold by transferring the concavo-convex surface from the concavo-convex surface of the produced surface relief type hologram, and then transferring the surface shape of the electroforming mold to a thin film. A large amount of surface relief type diffraction gratings can be produced. An example of a method for producing a mold in which an uneven surface capable of diffusing light is formed is shown in a document “Continuous and easy-to-understand magneto-optical disk (published by Optronics Inc., 1990)”. That is, a concavo-convex pattern of a target diffuser is formed on a glass substrate, and a silver or nickel film is formed (conductivity treatment) on the pattern formation surface by a vacuum deposition method or a sputtering method,
A master electroforming mold can be produced by a step of laminating nickel by electroforming and peeling it from a glass plate.
A large number of fine irregularities can be formed using this master electromold.

The original mold for the electroforming mold of the diffuser is shown in FIGS.
You can make it like this. Mask diffuser 4 of FIG.
6 has a large number of small openings 50 in the center, and is composed of a diffuser portion 48 having small openings and a blocking surface 52 having no openings. Laser light 54 is projected onto the mask diffuser 46. The light passes through a large number of small openings 50 in the diffuser portion 48 and is diffused toward the photosensitive film 56. After the exposure, if necessary, the photosensitive film 56 is developed to obtain a diffuser. When the He-Ne laser (633 nm) is applied to the surface relief hologram diffuser thus formed, the illumination pattern of the diffused light is shaped. Illumination patterns include ellipses and squares. If the contour of the diffuser is an ellipse, it becomes an ellipse, and if it is a square, it becomes a square.
Further, the spread of diffused light becomes wider when the distance between the diffuser and the photosensitive material is shorter, and narrower when the distance is farther. The light intensity distribution of the illumination pattern is measured as shown in FIG. The molds from which the electro-molds for surface relief gratings are based can be used as various types of gratings are commercially available.

The surface relief type hologram diffuser and the mold for the surface relief type diffraction grating having the irregular surface capable of scattering light are formed into a sheet, a flat plate or a roll or a part of the surface of a substrate. It is possible to use a product having an uneven surface that can scatter light over the entire surface or a necessary part, and to be attached to a pressure device or sandwiched between the uneven surface and the pressure device. May be. You may add heat, light, etc. in the process of pressing. It is necessary to design the degree of unevenness of the mold in which the uneven surface capable of scattering light is usually formed in consideration of being deformed by curing the thin film layer.

[0027]

EXAMPLES Hereinafter, the use of the present invention will be described in detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 A commercially available photoresist for semiconductor (AZ-1500 manufactured by Shipley) was dropped on a glass substrate and spin-coated at 1000 rpm, and then 100 ° C.
Prebaked for 1 minute with Ar, as shown in FIGS.
20 at 50 mW / cm ² using a laser (488 nm)
Second exposure. Further, it was developed with a dedicated developer. A nickel master electroforming mold, which is a mold for a diffuse reflector, was produced from the uneven surface formed here. Then, using this electroforming mold, a thin film layer was formed on the surface on which irregularities were to be formed, and the metal film surface of the master electroforming mold was pressed against the thin film layer. As a result, a thin film layer, which was a surface relief hologram diffuser having many fine irregularities on the surface, was formed.
Specifically, the unevenness of the thin film layer is obtained as follows. The following thin film forming solution was spin-coated on a thin glass substrate to obtain a thin film layer having a thickness of 2 μm. Next, a laminator (roll laminator HLM) is used so that a fine-shaped concave-convex surface is in contact with an electroforming sheet (master electroforming sheet) of a diffuse reflection plate.
1500, trade name of Hitachi Chemical Techno Plant Co., Ltd.)
A substrate in which a thin film layer and an electroforming sheet are laminated on a glass substrate by laminating at a substrate temperature of 90 ° C., a roll temperature of 80 ° C., a roll pressure of 0.7 MPa (7 Kg / cm ² ) and a speed of 0.5 m / min. Got Next, the electroforming sheet was peeled off to obtain a surface relief type hologram diffuser which was a thin film layer on the surface of the glass substrate having irregular irregularities. This substrate was exposed to a light ray (high-pressure mercury lamp) for curing the thin film layer at 100 mJ / cm ² using a parallel light exposure device MAP1200L (manufactured by Dainippon Screen Mfg. Co., Ltd.). This substrate is placed in an oven at 240 ° C for 20 minutes (clean oven CS
O-402, manufactured by Kusumoto Kasei Co., Ltd.) and heated to room temperature. Similarly, an electroforming template of a surface relief type diffraction grating was prepared and transferred to prepare a diffraction grating having grooves in the vertical and horizontal directions. A light-controlled diffuser was produced by stacking the obtained surface relief type diffraction grating and the surface relief type hologram diffuser. Al was sputter-deposited on this light control diffuser to prepare a diffuse reflector.

Thin film forming solution: Styrene, methyl methacrylate, ethyl acrylate, acrylic acid, glycidyl methacrylate copolymer resin was used as a polymer (polymer A). The molecular weight is 35,000 and the acid value is 110. Parts are parts by weight (same below). (Polymer) Polymer A 70 parts (monomer) pentaerythritol tetraacrylate 30 parts (photoinitiator) Irgacure 369 (Ciba Specialty Chemicals) 2.2 parts N, N-tetraethyl-4,4'-diaminobenzophenone 2. 2 parts (solvent) propylene glycol monomethyl ether 492 parts (polymerization inhibitor) p-methoxyphenol 0.1 part (surfactant) perfluoroalkyl alcoholate 0.01 part

(Embodiment 2) In the present embodiment, the reflection characteristic of the diffuse reflection plate for the reflection type LCD is improved. Figure 8
As shown in, external light passes through the polarizing plate 62, the phase difference plate 64, the color filter 66, and the liquid crystal 68, the surface relief hologram diffuser 70, and the metal deposited on the surface relief diffraction grating. It is reflected by the film and once again passes through the surface relief hologram diffuser. This diffuse reflector is the film of FIG. 5 (d) which has been subjected to the step of attaching a metal film to the diffraction grating surface of FIG. However, since the uneven surface of the diffuser is faced downward, the diffuser is made in another process. As the metal film, an Ag vapor deposition film or an Al vapor deposition film having a high reflectance is preferable. The adhesive has a refractive index larger than that of the material used for the surface relief hologram diffuser by 0.2 or more. This is to maintain the performance of the diffuser and to reflect the light obliquely scattered by the metal film at the interface with the diffuser. Since the color filter is made up of red, green, and blue pixels, the incident light also becomes red, green, and blue and reaches the diffuse reflection plate for reflection. In order to improve the reflection efficiency, it is preferable to incorporate a metal film diffraction grating for each pixel corresponding to each wavelength.

Regarding the diffusion characteristics of this diffuse reflector, the diffusion area is limited to 30 ° or less as shown by the solid line in FIG. 9 to improve the brightness and contrast. The dotted line in FIG. 9 shows a case where the diffuser has no directivity of scattered light as a comparative example. It can be seen that when there is no directivity, there is a spread at the bottom of the diffusion angle, and the brightness at the front is reduced.

[0032]

EFFECTS OF THE INVENTION By using a diffuse reflection plate in which a surface relief type diffraction grating and a surface relief type hologram diffuser having directivity for diffusion are combined, it becomes easy to control the scattering direction and the focusing range. .

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a diffuse reflection plate composed of a surface relief type diffraction grating and a surface relief type hologram diffuser which are laminated.

FIG. 2 is an explanatory diagram showing a method for measuring a reflection characteristic of a diffuse reflector.

FIG. 3 is a schematic view showing a UV transfer method.

FIG. 4 is a cross-sectional view showing a UV curing transfer film of a surface relief type diffraction grating.

5 (a), (b), (c), and (d) are process diagrams for producing the diffuse reflection plate of the present invention.

FIG. 6 is an explanatory diagram showing a method for manufacturing a surface relief hologram diffuser.

FIG. 7 is an explanatory diagram showing a method for manufacturing a surface relief hologram diffuser.

FIG. 8 is a configuration diagram showing a configuration of a reflective LCD substrate.

9 (a) is an explanatory view showing the relationship between the scattering angle and the relative scattering intensity for the diffuse reflection plate shown in FIG. 1 (a solid line indicates a diffuser having directivity, and a dotted line indicates no directivity). The scattering angle θ is an angle formed by incident light and light scattered vertically as shown in FIG. 1, where (a) is the horizontal reflection characteristic and (b) is the vertical reflection characteristic.

[Explanation of symbols]

θ. 12. Diffuse reflection plate made of a film having an angle of emission of 10.3 layers of diffracted light emitted after being diffracted by a hologram Surface relief type hologram diffuser 14. 15. Surface relief type diffraction grating with a groove formed in the vertical direction 16. 18. Surface relief type diffraction grating with lateral grooves 18. Metal film 20. Incident laser light 22. Scattered laser light 24. Incident laser light and its direction 26. Luminance meter 28. Diffuse reflection plate for reflection 30. Direction of incident light whose incident direction is a direction vector (Sx, Sy, Sz) 32. The range of the upper and lower incident angles Sx is -sin (θ1) <
The range of Sx <sin (θ1) and the left and right scattering angles Sy is −
A region 34. indicating the range of incident light in which sin (θ2) <Sy <sin (θ2). Transfer roll 36. Processed film 38. Feed roll 40. UV curable resin 42. Transparent resin such as PET 44. Adhesive 46. Mask diffuser 48. Diffuser portion of mask diffuser 50. Small diffuser opening 52. Blocking surface 54. Laser light 56. Glass substrate coated with photosensitive film 58. Exposed part 60. Reflected light 62. Polarizing plate 64. Retardation plate 66. Color filter 68. Liquid crystal 70. Surface relief type hologram diffuser 72. Surface relief type diffraction grating with a metal film on the grating surface 74. Transparent adhesive 76. Diffuse reflector

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/1335 500 G02F 1/1335 500 1/13357 1/13357 G03H 1/04 G03H 1/04 F term ( (Reference) 2H042 BA04 BA12 BA15 BA18 BA20 DA01 DA08 DA11 DB00 DE00 DE04 2H049 AA07 AA13 AA43 AA55 AA64 CA05 CA09 CA16 CA28 2H091 FA16 FA19 FC10 FC26 FC29 FC30 FD04 FD07 FD12 FD22 FD23 LA03 LA11 LA01 AFFLA10 LA13 LA13 LA00

Claims (20)

[Claims] 1. A diffuse reflection plate that reflects light and diffuses or condenses the light uniformly within a target range, and uses a surface relief type diffraction grating and a surface relief type hologram diffuser. Is a diffuse reflector. 2. A surface relief type diffraction grating or a surface relief type hologram diffuser of the diffuse reflection plate has a metal film or a refractive index of 1.
The diffuse reflector according to claim 1, wherein the diffuse reflector is covered with at least 6 dielectrics. 3. A reflection type surface relief type diffraction grating and a transmission type surface relief type hologram diffuser are used.
Alternatively, the diffuse reflection plate according to claim 2. 4. A unit direction vector S (Sx, Sy, Sz) of incident light with | S | = 1 when a laser beam of 10 mW in the visible wavelength range is reflected by a diffuser on the xy plane. , Certain variables θ1, θ2 (7 ° <θ1 or θ2 <4
0 °) exists, and the range of the incident angle Sx of the laser is |
Sx | <sin (θ1) and the range of the incident angle Sy is |
When Sy | <sin (θ2) is arbitrarily changed and the reflected light in the direction perpendicular to the diffuser is observed, the
%, The intensity is always higher than the light intensity of 2.7 / A (cd) when uniformly dispersed in the range A (sr) of the same solid angle as the incident angle range. The diffuse reflector according to any one of 3 above. 5. As a characteristic of a surface relief hologram diffuser used as a member of a diffuse reflector, when the direction vector of incident light is S _i (0,0,1), certain variables θ1 and θ2 are given.
(4 ° <θ1 <35 °; 90 °>θ2> θ1 × 1.5) exists and the unit direction vector S of transmitted light or reflected light
For (Sx, Sy, Sz), | Sx | <sin (θ
1) And 90% or more of the incident light is transmitted or reflected in the angle range of | Sy | <sin (θ2), and the peak half value width θ1w of the angular distribution of transmitted or reflected light intensity in the X-axis direction is 3 ° < 5. A surface relief hologram diffuser having a θ1w <20 ° is used.
The diffuse reflector according to any one of 1. 6. A surface relief type diffraction grating used as a member of a diffuse reflection plate has a characteristic that a direction vector of incident light is S _i.
When (0, 0, 1), certain variables θ1, θ2 (4 ° <
θ1 <35 °; 90 °>θ2> θ1 × 1.5) exists, and | Sx | <sin (θ1) and | Sy | <sin for the unit direction vector S (Sx, Sy, Sz) of scattered light
5. A surface relief type diffraction grating in which 90% or more of incident light enters in the angle range of (θ2) is used.
The diffuse reflector according to any one of 1. 7. A surface relief type diffraction grating and a surface relief type hologram diffuser are laminated.
7. The diffuse reflection plate according to claim 6. 8. The diffuse reflection plate according to claim 1, wherein a surface relief type diffraction grating and a surface relief type hologram diffuser are formed on both front and back surfaces. 9. The diffuse reflection plate according to claim 1, wherein the surface relief type diffraction grating and the surface relief type hologram diffuser are formed on the same surface. 10. A surface relief hologram in which the angular range of scattered light is controlled by exposing a photosensitive material with a laser through a mask diffuser hole consisting of a hole for making an illumination pattern and a diffuser, and controlling the angle range of the scattered light. The diffuse reflector according to any one of claims 1 to 9, wherein a diffuser is used. 11. The diffuse reflection plate according to claim 1, wherein the surface relief type diffraction grating is laminated so that the directions of the grating grooves are non-parallel. 12. The surface relief type diffraction grating is arranged vertically and horizontally on the same surface or on the front and back surfaces so that the grating grooves are not parallel to each other. Diffuse reflector. 13. The laminated surface relief hologram diffuser is adhered via an adhesive layer.
The diffuse reflection plate according to claim 12. 14. The diffuse reflection plate according to claim 9, wherein a stack of surface relief hologram diffusers sandwiches a spacer. 15. The diffuse reflection plate according to claim 12, wherein the surface relief hologram diffuser is obtained by transferring a surface relief hologram from a transfer roll mold. 16. The diffuse reflection plate according to claim 15, wherein the surface relief hologram diffuser uses a UV curable resin as a material of the surface relief hologram. 17. The diffuse reflection plate according to claim 15, wherein the surface relief hologram diffuser uses a thermoplastic resin as a material of the surface relief hologram. 18. A reflective liquid crystal display device using the diffuse reflection plate according to any one of claims 1 to 17 as a diffusion reflection plate. 19. A member for lighting equipment, which uses the diffuse reflection plate according to any one of claims 1 to 17 as a diffusion reflection plate. 20. An optical communication member using the diffuse reflection plate according to any one of claims 1 to 17 as a diffusion reflection plate.