JP2003084128A - Sheet member for projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical member to correct tones in a projection device, particularly in a device using Digital Light Processing (R) as the image source. SOLUTION: The sheet member for a projection device exhibits the maximum absorption wavelength in the range from 530 to 570 nm in the 400 to 800 nm wavelength region, 30 to 80% transmittance at the maximum absorption wavelength, <=150 nm half width of the maximum absorption band, and transmittances at 450 nm and 620 nm higher by >=5% than the transmittance at the maximum absorption wavelength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like member used as a constituent member of a projection device such as a front projector or a rear projection television.

[0002]

2. Description of the Related Art Conventionally, a CRT (cathode ray tube) has been mainly used as an image source of a projection device such as a front projector or a rear projection television, and liquid crystal has begun to be used as an image source suitable for digital broadcasting. There is. Furthermore, in recent years, a high-definition projection device using digital light processing (DLP ^™ ) incorporating a digital micromirror device (DMD ^™ ), which is an optical semiconductor chip developed by Texas Instruments Inc. Development is underway at each company.

[0003]

In these projection apparatuses, particularly those using digital light processing as an image source, there is a problem that the color tone when projecting an image is greenish. An object of the present invention is to provide an optical member for color tone correction that can solve this problem.

[0004]

As a result of intensive studies, the present inventor has found that a sheet-like member having specific optical physical properties is suitable for the above purpose, and completed the present invention. That is, the present invention has a maximum absorption wavelength at a wavelength of 400 to 800 nm in the range of 530 to 570 nm, a transmittance at the maximum absorption wavelength of 30 to 80%, a full width at half maximum of the maximum absorption band of 150 nm or less, and a wavelength of 450 nm. And a sheet-like member for a projection device, the transmittance of which at a wavelength of 620 nm is higher than that at the maximum absorption wavelength by 5% or more.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The sheet-shaped member of the present invention has a maximum absorption wavelength of 530 to 570 nm, preferably 5 at a wavelength of 400 to 800 nm.
It is in the range of 40 to 560 nm. If the maximum absorption wavelength is less than 530 or exceeds 570 nm, the green light absorption efficiency is insufficient.

The sheet-like member of the present invention has a transmittance of 30 to 80%, preferably 5 at the maximum absorption wavelength.
It is in the range of 0 to 75%, and the full width at half maximum of the maximum absorption band is 150 nm or less, preferably 100 nm or less. If the transmittance at the maximum absorption wavelength is less than 30%, the green light absorptivity may be too high, which may adversely affect the color tone, and the transmittance at the maximum absorption wavelength may be 8%.
If it exceeds 0%, the ability to absorb green light is insufficient. Further, if the full width at half maximum of the maximum absorption band exceeds 150 nm, effective blue light or red light other than green light may be affected and the brightness of the image may be reduced.

The full width at half maximum of the maximum absorption band referred to here is
Is the wavelength on the horizontal axis and the transmission on the vertical axis, as schematically shown in FIG.
The transmittance curve between wavelengths 400-800 nm
The maximum absorption wavelength λ_maxOn the side with high transmittance
Draw a baseline AB that touches the transmittance curve,
Absorption wavelength λ_maxTransmittance T at_pAnd the wavelength λ_maxIn the
Transmittance T on spline_bOf the point that bisects the line connecting
Transmittance T_1/2Is the width of two wavelengths. Shown in Figure 1
If you explain using symbols, T_1/2= (T_p+ T_b) / 2
And this transmittance T_1/2Two wavelengths λ₁And λ
₂Difference with_1/2(= Λ ₂−λ₁) Is the full width at half maximum.

Further, the sheet-shaped member of the present invention has a difference in transmittance at a wavelength of 450 nm of 5% or more, preferably 10%, as compared with the transmittance at the maximum absorption wavelength.
The difference is high, and the difference in the transmittance at a wavelength of 620 nm is 5% or more, preferably 10% or more. When the difference of the former is less than 5%, the absorption of green light with respect to the absorption of blue light is insufficient, and when the difference of the latter is less than 5%, the absorption of green light with respect to the absorption of red light. Is not sufficient, and in either case, it is not satisfactory from the viewpoint of color tone correction.

The sheet-like member having the above-mentioned desired optical properties is made of a transparent resin as a base material, and a dye is added to the substrate. At that time, the kind, the physical properties, etc. of the transparent resin, the kind, the physical properties, the amount, etc. of the dye are used. Can be suitably produced by appropriately selecting and adjusting.

Examples of the transparent resin include a methyl methacrylate polymer, a methyl methacrylate-methyl acrylate copolymer, a methyl methacrylate-styrene copolymer, and a methyl methacrylate-styrene-butadiene copolymer. Acrylic resin, polycarbonate resin,
Amorphous polyolefin resins and the like can be mentioned, and if necessary, two or more of them can be used. Further, these resins may be rubber-reinforced.

The dye contained in the transparent resin may be appropriately selected from commercially available dyes. Examples thereof include Rhodamine B manufactured by Taoka Chemical Co., Ltd .; Sumiplast Viole manufactured by Sumika Finechem Co., Ltd.
t RR, SumiplastViolet B, Sum
iplast Red 3B; Kay manufactured by Nippon Kayaku Co., Ltd.
aset Blue A2R; Macro manufactured by Bayer
lex Violet3R; NK-276, NK-79, NK-67, NK-2 manufactured by Hayashibara Biochemical Laboratory Co., Ltd.
039, NK-77, NK-2707, NK-737,
NK-616, NK-1973, NK-1050, NK
-3995, NK-3997, NK-97, NK-37
5, NK-376, NK-383, NK-526, NK
X-1324, NKX-1323, NKX-1325,
NK-3468, NK-2807, NK-3576 and the like can be mentioned, and if necessary, two or more kinds of them can also be used.

Further, if necessary, the transparent resin may be added to the transparent resin.
One kind or two or more kinds of various additives such as an antioxidant, a plasticizer, a release agent, a colorant, an antistatic agent, an ultraviolet absorber, a flame retardant and a light diffusing agent may be contained.

The sheet-like member of the present invention is used as an optical member in a projection device such as a front projector or a rear projection television, and particularly preferably in a projection device using digital light processing as an image source. As the optical member in the front projector, a filter installed in the optical path inside the projector is suitable, and as the optical member in the rear projection television,
A screen component such as a filter installed in the optical path inside the projector that emits a television image, a Fresnel lens sheet that forms a screen, a lenticular lens sheet, or a front panel is suitable.

The filter in the front projector and the filter in the projector for the rear projection television may be, for example, those obtained by cast molding or those obtained by extrusion molding. Further, it may have a hard coat performance, an antistatic performance, an antireflection performance, or the like. From the viewpoint of image clarity, the filter is preferably a flat plate and does not essentially diffuse light, and its haze value (cloudiness value) is preferably 5% or less.

The Fresnel lens sheet in the above rear projection television may be, for example, one obtained by cast molding, or a Fresnel lens shape obtained by press molding on a sheet-shaped substrate obtained by extrusion molding, cast molding or the like. May be added, or an ultraviolet curable resin may be cured so as to form a Fresnel lens shape on the surface of a sheet-shaped substrate obtained by extrusion molding, cast molding or the like. . Further, the surface opposite to the surface having the Fresnel lens shape may be surface-treated with a surface mat, a prism, a lenticular lens, a linear Fresnel lens, or the like.

The lenticular lens sheet in the rear projection television may be, for example, one obtained by extrusion molding or one obtained by cast molding, or extrusion molding or cast molding. The lenticular lens shape may be imparted to the sheet-shaped base material obtained by, for example, press molding, or the surface of the sheet-shaped base material obtained by extrusion molding, cast molding or the like may be lenticular with an ultraviolet curable resin. It may be obtained by bonding a film having a lens shape to a sheet-shaped substrate.

The front panel in the rear projection television may be, for example, one obtained by extrusion molding, one obtained by cast molding, a hard coat or a low coat. It may be one that has been subjected to a surface treatment such as a reflection coat, a surface mat, a prism, a lenticular lens,
A surface-treated lens such as a linear Fresnel lens may be used.

[0018]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. The spectral transmittance was measured using a self-recording spectrophotometer [330 type, manufactured by Hitachi, Ltd.].

Example 1 100 parts by weight of methyl methacrylate was mixed with 0.002 parts by weight of 2,2'-azobisisobutyronitrile, and the mixture was heated to 70 ° C.
Was pre-polymerized to obtain a partial polymer syrup containing 5% by weight of the polymer. 100 parts by weight of the partial polymer syrup was mixed with Rhodamine B manufactured by Taoka Chemical Co., Ltd.
0.003 parts by weight of Sumi manufactured by Sumitomo Chemical Co., Ltd.
0.01 parts by weight of sorb200 (ultraviolet absorber) and 0. 0% of azobisisobutyronitrile (polymerization initiator).
08 parts by weight were added and mixed, and this mixture was poured into a cell composed of two float glasses and a polyvinyl chloride gasket, which was then heated at 70 ° C. for 3 hours and then at 120 ° C.
Polymerization was carried out for a time to obtain a sheet-shaped member having a thickness of 2 mm. Wavelength 400 to 800 nm in the thickness direction of the obtained sheet-shaped member
As a result of measuring the spectral transmittance in, the maximum absorption wavelength is 5
The transmittance at 55 nm and the maximum absorption wavelength is 55.5.
%, The full width at half maximum of the maximum absorption band is 45 nm,
The transmittance at 0 nm was 92.0% and the transmittance at a wavelength of 620 nm was 92.7%. This sheet-shaped member is set as a filter in the optical path of a front projector that uses digital light processing as an image source, and as a result of observing by projecting an image on a screen, as compared with when the sheet-shaped member is not set, The white part of the image was beautiful without green.

Example 2 Rhodamine B manufactured by Taoka Chemical Industry Co., Ltd.
Instead of adding 03 parts by weight, Sumika Finechem Co., Ltd.
Made Sumiplast Violet RR 0.00
The same operation as in Example 1 was carried out except that 17 parts by weight was added to obtain a sheet-shaped member having a thickness of 2 mm. As a result of measuring the spectral transmittance of the obtained sheet-shaped member at a wavelength of 400 to 800 nm in the thickness direction, the maximum absorption wavelength was 555 nm,
The transmittance at the maximum absorption wavelength was 57.0%, the full width at half maximum of the maximum absorption band was 110 nm, the transmittance at a wavelength of 450 nm was 87.3%, and the transmittance at a wavelength of 620 nm was 82.0%. This sheet-shaped member is set as a filter in the optical path of a front projector that uses digital light processing as an image source, and as a result of observing by projecting an image on a screen, as compared with when the sheet-shaped member is not set, The white part of the image was beautiful without green.

[0021]

According to the sheet-like member for a projection device of the present invention, when a video image is projected in a projection device such as a front projector or a rear projection television, particularly a projection device using a digital light processing as a video source. It is possible to prevent the color tone of the image from becoming greenish, improve the color purity of the image, and display a more natural image.

[Brief description of drawings]

FIG. 1 is a diagram showing a transmittance curve for explaining a concept of a half width of a maximum absorption band.

[Explanation of symbols]

λ _max ... maximum absorption wavelength AB ... baseline T _p ... transmittance at maximum absorption wavelength T _b ... transmittance on baseline at maximum absorption wavelength T _1/2 ... T _p Intermediate point of T _b = (T _p + T _b ) / 2 X _1/2 ... Width of wavelength showing half width

Claims (2)

[Claims] 1. The maximum absorption wavelength at a wavelength of 400 to 800 nm is in the range of 530 to 570 nm, the transmittance at the maximum absorption wavelength is 30 to 80%, the full width at half maximum of the maximum absorption band is 150 nm or less, and the wavelength is 450 nm. And a transmittance at a wavelength of 620 nm that is 5% or more higher than a transmittance at the maximum absorption wavelength, respectively. 2. The sheet-shaped member according to claim 1, wherein the projection device is a front projector or a rear projection television.