JPH08278405A - Optical filter - Google Patents

Abstract

PURPOSE: To provide an optical filter capable of obtaining a projected picture in which a color of an object is reproduced faithfully without being influenced by the color temp. of a light source. CONSTITUTION: In the optical filter in which a colored layer 4 consisting of a resin and a colorant is provided on one surface of a transparent base material 3, the colorant is composed of a blue colorant whose (x) value in XYZ displaying system chromaticity diagram is within a range of 0.15-0.26 and (y) value is within a range of 0.11-0.28 and a red colorant whose (x) value is within a range of 0.37-0.46 and (y) value is within a range of 0.25-0.30, and a hue is applied so that a chromaticity coordinates of a light emitted from a light source may be in the point of ordinates within a deviation of ±0.010 from a black body locus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical filter for a liquid crystal projector.

[0002]

2. Description of the Related Art In recent years, along with the widespread use of home-use 8 mm video, there has been an increasing demand for showing and watching video footage on the spot, and portable lightweight liquid crystal projectors are rapidly becoming widespread. However, most of the light sources used in these liquid crystal projectors are halogen lamps. This halogen lamp is a type of incandescent light bulb, and is widely used because of its high brightness, stable output, and low cost, but since the spectral energy is not uniform, it does not match the actual color when used as a light source. In contrast, since a yellowish projected image is displayed, the viewer feels uncomfortable.

By the way, there is a color temperature as a scale representing the color of a light source. This color temperature is a numerical value used to represent the chromaticity of a black body radiation or a light source having a spectral distribution close to it. The color temperature (K) of light due to black body radiation at various temperatures is CIE (International Illumination Commission). Meeting) 1960-UCS
It is represented by a curve as shown in FIG. 1 in the chromaticity diagram. This curve is called the blackbody locus. A group of straight lines intersecting this locus is a color-matching temperature line. Further, it is defined that this isocolor temperature line is orthogonal to the black body locus on the CIE (International Commission on Illumination) 1960-UCS chromaticity diagram. (“Encyclopedia of Chemistry” 24th edition, 1980, edited by Encyclopedia of Chemistry)

Generally, since the spectral distribution of an ordinary light source is different from the spectral distribution of black body radiation, its chromaticity coordinates deviate from the black body locus. Therefore, the color temperature of the light source in this case is obtained from the isochromatic temperature line by plotting the chromaticity coordinates of this light source in FIG. However, this method causes the inconvenience that all coordinate points on the color matching temperature line are expressed as the same color. Therefore, it is expressed as a deviation which distance (up or down) the black body locus is. , Each coordinate point is expressed.

In order to solve the inconvenience that the viewer feels uncomfortable as described above, a color corrector is conventionally used to correct the color tone and color distortion of a video signal from a video source such as an LVD or VTR by a color corrector. Methods such as a collector method and an anode voltage control method in which the color temperature conversion is performed by controlling the anode voltage of the CRT in the projection tube so as to be associated with the characteristic to be corrected and adjusting the amount of light projected from the CRT are used. It was However, the former has a problem that the color collector needs to be adjusted in addition to the adjustment of the projection display device itself, and the latter has a problem in that the anode voltage is changed according to the environmental conditions such as ambient light in the place where the projection display device is installed. It was necessary to change it, and it was difficult to standardize the color temperature correction value.

[0006]

The present invention has been made to solve the above problems, and provides an optical filter capable of obtaining a projection image in which the color of an object is faithfully reproduced. The purpose is to

[0007]

The inventors of the present invention have made extensive studies to solve the drawbacks of the conventional liquid crystal projector. As a result, they found that the closer the chromaticity to the black body locus, the more faithfully the color of the object is reproduced. Furthermore C
When the chromaticity of the light source is represented in the IE (International Commission on Illumination) 1960-UCS chromaticity diagram, the chromaticity coordinates are converted to coordinate points within ± 0.010 of the deviation from the black body locus, thereby reducing the It came to solve the problem. The present invention has been completed based on such findings. Here, the deviation means the distance from the black body locus.

That is, the optical filter of the present invention is characterized in that a colored layer containing a specific blue colorant and a specific red colorant is provided on at least one surface of a transparent substrate. It is possible to obtain a clear image that faithfully reproduces the color of the image.

The present invention will be described below with reference to the drawings. Here, FIG. 2 is a sectional view of the optical filter according to the present invention.

The transparent substrate 3 used in the present invention may be any transparent one, and examples thereof include a synthetic resin film, a synthetic resin plate, an acrylic plate, and a glass plate, but are not limited thereto. In addition, the thickness of the transparent substrate is preferably 2 to 400 μm, more preferably 50 to 250 μm from the viewpoint of workability.

The colored layer 4 is a layer composed of a resin and a colorant, and when the light emitted from the light source passes through the optical filter of the present invention, its chromaticity is ± as a deviation from the black body locus.
It is colored so as to be converted within 0.010.

The resin used for the colored layer 4 includes vinyl acetate resin, modified vinyl acetate resin, modified vinyl acetate / acrylic copolymer resin, ethylene / vinyl acetate copolymer resin,
Selected from polyester resin, acrylic copolymer resin, acrylic silicone resin, cellulose resin, vinyl chloride / vinyl acetate copolymer resin, styrene resin, urethane resin, epoxy resin, modified polyvinyl alcohol resin, acrylonitrile rubber, etc. Further, one kind or a mixture of two or more kinds can be used.

As the colorant, C.I. I. Solvent Red 3, 8, 18, 24, 27, 35, 49, 82, 8
3, 84, 100, 109, 122, 132, 218,
C. I. Solvent Blue 25, 35, 48, 70, 9
4, 117, oil-soluble dyes such as C.I. I. Disperse Blue 7, 60, C.I. I. Disperse dyes such as Disperse Red 60, C.I. I. Pigment Red 101, C.I. I.
Pigment Blue 27, an inorganic color pigment such as C.I. I.
Pigment Red 2, 3, 5, 17, 22, 23, 4
8, 237, C.I. I. Pigment Blue 15 and other organic colored pigments are listed, but due to their light resistance and heat resistance,
Pigment type colorants are preferred.

The blue colorant and the red colorant are JIS-based.
It is specified by the x and y values of the XYZ chromaticity diagram in Z-8701. The x and y values are tristimulus values X and Y, respectively.
Assuming Y and Z, x = X / (X + Y + Z) y = Y / (X + Y + Z) where x + y + z = 1.

The blue colorant is CIE (International Commission on Illumination) X
In the YZ display chromaticity diagram, the x value is 0.15 to 0.2.
6, those having y values in the range of 0.11 to 0.28 are preferable. The x value is set to 0.15 or more because when a halogen lamp (color temperature 3000K) that is a light source of a liquid crystal projector is used to obtain transmitted light, the transmitted light becomes greenish blue and red. This is to prevent the y value from becoming too high when it is combined with a colorant so as to prevent the image from becoming greenish,
0.26 or less, the transmitted light becomes purple blue,
This is to prevent the y value from becoming too low and a purplish image when combined with a red colorant.

Further, the y value of 0.11 or more prevents the transmitted light from becoming violet blue, and when combined with a red coloring agent, the x value becomes too low to produce a greenish image. This is because 0.28 or less is to prevent the transmitted light from becoming greenish blue, and when combined with a red coloring agent, the x value becomes too high and a purplish image is formed. .

On the other hand, the red colorant has an x value of 0.37-0.
Those having a 46 and y value in the range of 0.25 to 0.30 are preferable. The x value was set to 0.37 or more because the halogen lamp (color temperature 3000K) that is the light source of the liquid crystal projector
Is used to obtain transmitted light, the transmitted light becomes bluish red, and when combined with a blue colorant, the y value becomes too low to prevent a purplish image. 46
The following is to prevent the transmitted light from becoming greenish red, and when combined with a blue colorant, the y value becomes too high and the image becomes greenish.

Further, the y value of 0.25 or more prevents the transmitted light from becoming purplish blue and prevents the purplish image from becoming too low when combined with a red coloring agent. The reason for setting 0.30 or less is to prevent the transmitted light from becoming greenish blue, and when combined with a red coloring agent, the x value becomes too high and the image becomes greenish. .

The x and y values were obtained by dispersing or dissolving 10 parts by weight of each colorant in 150 parts by weight of anone and then adding 100 parts by weight of Byron # 300 (manufactured by Toyobo Co., Ltd.) to form a coating film. The measured value.

The amount of the colorant added cannot be generally determined depending on the type of the colorant, but is preferably in the range of 5.0 to 40.0 parts by weight, preferably 10.0 to 4 parts by weight, based on 100 parts by weight of the resin.
A range of 30.0 parts by weight is more preferable. The amount of 5.0 parts by weight or more is for facilitating toning, and is 40.0
The reason why the amount is less than or equal to parts by weight is to allow the resin to sufficiently retain the colorant.

The thickness of the colored layer cannot be generally determined depending on the type of resin used, but is usually 0.5 to 20 μm, preferably 1 to 10 μm. The reason why the thickness is 0.5 μm or more is to obtain sufficient coloring property.
The reason for setting below is to prevent uneven density during coating.

In the optical filter of the present invention, the deviation of the chromaticity coordinates of the light emitted from the light source from the black body locus ± 0.010.
The hue is given so as to be converted into the coordinate points within. The reason for setting within ± 0.010 is to make the color tone of the projected image more natural.

If desired, a leveling agent, an antistatic agent, an ultraviolet absorber, and other additives may be added within a range that does not impair the physical properties of the coating film.

The optical filter of the present invention mainly has the above-mentioned structure, but if necessary, an undercoat layer may be provided on the transparent substrate. Further, in consideration of light resistance and the like, an ultraviolet absorber is used as the undercoat layer. You may mix. It is also possible to laminate an ultraviolet absorbing layer containing an ultraviolet absorber on the opposite surface of the colored layer with the transparent substrate interposed.

The optical filter of the present invention comprises a roll coater, a wire bar coater, an air knife coater, a gravure coater, which is a coating solution prepared by dissolving or dispersing the above composition in a solvent such as butyl acetate or anone on a transparent substrate. It can be manufactured by coating and drying by a method or the like.

The chromaticity when the light emitted from the light source is transmitted through the optical filter thus obtained is
It is represented by chromaticity coordinates u and v according to the CIE (International Commission on Illumination) 1960-UCS chromaticity diagram. The u and v are represented by the chromaticity coordinates x and y described above as follows.

U = 4x / (-2x + 12y + 3) v = 6y / (-2x + 12y + 3)

[0028]

The optical filter of the present invention comprises a transparent substrate on which a colored layer formed by mixing a resin and a colorant is provided, and further, when the light emitted from the light source passes through the optical filter, Deviation of chromaticity coordinates of transmitted light from black body locus ±
By converting into the coordinate points within 0.010, it is possible to obtain a projection image in which the color of the object is faithfully reproduced.

[0029]

Embodiments of the present invention will be described below. In addition, "part" in this example represents the weight basis of solid content unless otherwise specified.

Example 1 A transparent polyester film (O type: manufactured by DIAFOIL Hoechst) having a thickness of 188 μm was coated with a coating solution for a colored layer having the following composition by a roll coater to form a colored layer having a dry film thickness of 5 μm. An optical filter having the above was obtained. The coating liquid for the colored layer was obtained by adding a solvent to a colorant, introducing the solvent into a disperser, dispersing the colorant until the colorant became uniform, and adding a polyester resin to the dispersion to stir. The x and y values of each colorant are
10 parts of each colorant was added to 150 parts of Anon and dispersed, and 100 parts of Byron # 300 was mixed to form a coating film, and measurement was performed.

[Coloring layer] Polyester resin 100 parts (Byron # 300: manufactured by Toyobo Co., Ltd.) Blue colorant (x value 0.20 y value 0.23) 10 parts (cyanine blue 4920: manufactured by Dainichiseika Kogyo KK) Red colorant (x value 0.37 y value 0.28) 5 parts (Tinting Red J-409: Sanyo Dye Co., Ltd.) Butyl acetate 100 parts Anone 100 parts

Example 2 A transparent polyester film (O type: manufactured by DIAFOIL Hoechst) having a thickness of 188 μm was coated with a coating solution for a colored layer having the following composition obtained in the same manner as in Example 1 using a roll coater. An optical filter having a colored layer having a dry film thickness of 5 μm was obtained. The x value and the y value of each colorant were also measured in the same manner as in Example 1.

[Coloring layer] Polyester resin 100 parts (Byron # 300: manufactured by Toyobo Co., Ltd.) Blue colorant (x value 0.20 y value 0.23) 5 parts (cyanine blue 4920: manufactured by Dainichiseika Kogyo Co., Ltd.) Red colorant (x value 0.37 y value 0.28) 5 parts (Tinting Red J-409: Sanyo Dye Co., Ltd.) Butyl acetate 100 parts Anone 100 parts

Example 3 A transparent polyester film (O type: manufactured by DIAFOIL Hoechst) having a thickness of 188 μm was coated with a coating solution for a colored layer having the following composition using a roll coater to form a colored layer having a dry film thickness of 5 μm. An optical filter having the above was obtained. The coating liquid for the coloring layer was obtained by adding a solvent to the coloring agent and stirring for several hours, and then adding a polyester resin and stirring. The x value and the y value of each colorant were measured by adding 10 parts of each colorant to 150 parts of anone and stirring the mixture to form 100 parts of Byron # 300 to form a coating film.

[Coloring layer] Polyester resin 100 parts (Byron # 300: manufactured by Toyobo Co., Ltd.) Blue colorant (x value 0.16, y value 0.11) 5 parts (Victoria Blue F4R: manufactured by BASF) Red colorant (X value 0.41 y value 0.26) 5 parts (Neozapon Red BE: manufactured by BASF) Butyl acetate 100 parts Anon 100 parts

Comparative Example 1 An optical filter was obtained in the same manner as in Example 3 except that the blue colorant and the red colorant were changed as follows. The x value and the y value of each colorant were also measured in the same manner as in Example 3.

[Coloring Layer] Blue colorant (x value 0.14, y value 0.16) 5 parts (Victoria Blue BH: Hodogaya Chemical Co., Ltd.) Red colorant (x value 0.41 y value 0.26) ) 5 copies (Neozapon Red BE: BASF)

Comparative Example 2 An optical filter was obtained in the same manner as in Example 1 except that the blue colorant and the red colorant were changed as follows. Further, the x value and the y value of each colorant were also measured in the same manner as in Example 1.

[Coloring layer] 5 parts of blue coloring agent (x value 0.30 y value 0.31) (Paiogen Blue 6470: manufactured by BASF) Red coloring agent (x value 0.37 y value 0.28) 5 parts (Tinting Red J-409: Sanyo Dye Co., Ltd.)

Comparative Example 3 An optical filter was obtained in the same manner as in Example 3 except that the blue colorant and the red colorant were changed as follows. The x value and the y value of each colorant were also measured in the same manner as in Example 3.

[Coloring layer] Blue colorant (x value 0.15, y value 0.10) 5 parts (Victoria Blue F4R: manufactured by BASF) Red colorant (x value 0.41 y value 0.26) 5 parts (Neozapon Red BE: BASF)

Comparative Example 4 An optical filter was obtained in the same manner as in Example 3 except that the blue colorant and the red colorant were changed as follows. The x value and the y value of each colorant were also measured in the same manner as in Example 3.

[Coloring Layer] Blue colorant (x value 0.24 y value 0.30) 5 parts (Vali Fast Blue 2606: manufactured by Orient Chemical Industry Co., Ltd.) Red colorant (x value 0.41 y value 0.26) ) 5 copies (Neozapon Red BE: BASF)

Comparative Example 5 An optical filter was obtained in the same manner as in Example 3 except that the blue colorant and the red colorant were changed as follows. The x value and the y value of each colorant were also measured in the same manner as in Example 3.

[Coloring Layer] Blue colorant (x value 0.16 y value 0.11) 5 parts (Victoria Blue F4R: manufactured by BASF) Red colorant (x value 0.31 y value 0.31) 5 parts (Sumiplast Red 3B: Sumitomo Chemical Co., Ltd.)

Comparative Example 6 An optical filter was obtained in the same manner as in Example 3 except that the blue colorant and the red colorant were changed as follows. The x value and the y value of each colorant were also measured in the same manner as in Example 3.

[Coloring layer] 5 parts of blue colorant (x value 0.16 y value 0.11) (Victoria Blue F4R: manufactured by BASF) Red colorant (x value 0.48 y value 0.31) 5 parts (Vari Fast Red 1308: Orient Chemical Industry Co., Ltd.)

Comparative Example 7 An optical filter was obtained in the same manner as in Example 3 except that the blue colorant and the red colorant were changed as follows. The x value and the y value of each colorant were also measured in the same manner as in Example 3.

[Coloring Layer] 5 parts of blue coloring agent (x value 0.16 y value 0.11) (Victoria Blue F4R: manufactured by BASF) red coloring agent (x value 0.37 y value 0.21) 5 parts (Zapon Fast Red BB: BASF)

Comparative Example 8 An optical filter was obtained in the same manner as in Example 3 except that the blue colorant and the red colorant were changed as follows. The x value and the y value of each colorant were also measured in the same manner as in Example 3.

[Coloring Layer] Blue colorant (x value 0.16 y value 0.11) 5 parts (Victoria Blue F4R: manufactured by BASF) Red colorant (x value 0.29 y value 0.32) 5 parts (Ceres Red 7B: BAYER)

Comparative Example 9 An optical filter was obtained in the same manner as in Example 3 except that the blue colorant and the red colorant were changed as follows. The x value and the y value of each colorant were also measured in the same manner as in Example 3.

[Coloring layer] Blue colorant (x value 0.14, y value 0.13) 5 parts (Victoria Pure Blue FGA: BASF) Red colorant (x value 0.48 y value 0.31) 5 Department (Vali Fast Red 1308: Orient Chemical Industry Co., Ltd.)

Then, Examples 1 to 1 thus obtained
3 and the optical filters of Comparative Examples 1 to 9 were set in a liquid crystal projector (manufactured by Victor Company of Japan), and a brightness meter (BM
-7: manufactured by TOPCON) was used to measure the deviation from the black body locus on the 1960-UCS chromaticity diagram in the transmitted light from each filter.

The color reproducibility was visually evaluated with respect to the transmitted light from each filter. Regarding the evaluation result, the color was completely reproduced and the color was not reproduced.

Table 1 shows the results of these evaluations.

[0057]

[Table 1]

In Examples 1 to 3, there was a slight deviation from the blackbody locus, but the image color reproducibility was good. On the other hand, in Comparative Examples 1 to 9, the deviation from the black body locus was large, and the color reproducibility of the image was poor. Specifically, in Comparative Examples 2, 4, 5, 6, and 8, the color was greenish, and in Comparative Examples 1, 3, 7, and 9, it was purpleish.

[0059]

As described above, in the present invention, the color of the object is controlled by using the optical filter in which the colored layer formed by using the resin and the specific coloring agent is provided on the transparent substrate. It has become possible to obtain a projection image that has not been reproduced before and that has been faithfully reproduced.

[Brief description of drawings]

Figure 1: CIE (International Commission on Illumination) 1960-UCS chromaticity diagram and blackbody locus

FIG. 2 is a sectional view of an optical filter according to the present invention.

[Explanation of symbols]

 1 ... Black body locus 2 ... Color temperature line 3 ... Transparent substrate 4 ... Colored layer

Claims (2)

[Claims] 1. CIE (International Commission on Illumination) 1960-UC
In the S chromaticity diagram, an optical filter is provided with a hue so that the chromaticity coordinates of the light emitted from the light source are converted into coordinate points within a deviation of ± 0.010 from the black body locus. 2. An optical filter comprising a transparent substrate and at least one surface thereof provided with a colored layer comprising a resin and a colorant, wherein the colorant is CIE (International Commission on Illumination) X.
In the YZ display chromaticity diagram, the x value is 0.15 to 0.26,
a blue colorant having ay value in the range of 0.11 to 0.28,
x value is 0.37 to 0.46, y value is 0.25 to 0.30
The optical filter according to claim 1, wherein a red colorant in the range of 1 is used.