JPH0157762B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multicolor optical filter useful for color image forming devices, and particularly to a color image pickup element or a color image pickup tube, and a method for manufacturing the same.

Polychromatic optical filters are widely used, such as color plates for oblique light flux restriction, color face plates for cathode ray tube displays, plates for photoelectric conversion elements for copying, and filters for single-tube color television cameras. Furthermore, particularly in recent years, with advances in semiconductor manufacturing technology, solid-state imaging devices have come to be used in place of conventional image pickup tubes as elements for converting two-dimensional images into electrical signals. for example
CCD (Charge Coupled Device) or
A solid-state image sensor called a BBD (Bucket Tricade Device) has a large number of finely divided light-receiving sections and a drive circuit for extracting information from these light-receiving sections, all housed in one chip, and is capable of capturing color images. In order to achieve this, it is necessary to further provide a polychromatic optical filter corresponding to the minute light-receiving surface. As a typical example of such a solid-state image sensor, a polychromatic optical filter used in various fields is used to improve the resolution of color images or to achieve more precise and high resolution as color image conversion devices become smaller. It is also expected to have excellent durability.

Commonly used polychromatic optical filters are red,
Three primary colors of green and blue, or cyan, magenta,
Most of the yellow reflected light has three primary colors arranged regularly, but some have two colors, four colors, or more. In terms of how the color elements are arranged,
Striped and mosaic shapes are common.

These conventionally known polychromatic optical filters are generally manufactured by a vapor deposition method. This vapor deposition method uses an interference filter, in other words, multiple layers of thin films with different refractive indexes are vapor-deposited to a predetermined thickness on a support, allowing only the desired wavelength range (color) to pass through due to the light interference effect. This is used to form a polychromatic optical filter. However, the polychromatic optical filter obtained by this method requires a complex process in which a number of different thin films (usually more than ten layers) must be deposited for each adjacent color element (unit photosensitive area), each layer having a precise thickness. Since it requires a process, it is costly and has a poor yield.

Another well-known manufacturing method is the so-called dyeing method. In the dyeing method, a resin such as polyvinyl alcohol or gelatin film is coated on a support to form a color element receiving layer (mordant layer), and a coloring substance (dye, etc.) is added to this to form color elements. It is something to do. For example, US Pat. No. 3,284,208 describes a method for manufacturing a fine stripe-like filter used in additive color photography using three primary colors using the following steps. That is, a gelatin layer made photosensitive by adding potassium dichromate is coated on a support, exposed in a pattern, and then washed with warm water to form a relief image.
Next, the gelatin layer remaining in the relief image is dyed with a first color dye (red) from a dye solution. Next, after coating an intermediate layer on top of this, a second gelatin layer containing potassium dichromate is applied, followed by exposure, formation of a relief image, and dyeing with a second color pigment (green). Let's do it. After further coating the intermediate layer, a third gelatin layer containing potassium dichromate is provided, followed by exposure, formation of a relief image, and dyeing with a third color dye (blue). Finally, a protective layer is applied to the top layer. Although it is possible to manufacture a polychromatic optical filter as described above, it has the disadvantage that the manufacturing process is complicated and pinholes and scratches are likely to occur during the manufacturing process. Polychromatic optical filters made in this way have a multi-layer structure and are therefore thick, making them preferable when used, for example, in single-position color imaging devices. do not have. This is because the use of such polychromatic optical filters requires imaging optics with a very deep depth of focus, so that all layers along with the photo sensor must be included in focus. It is from. Furthermore, due to the multilayer structure, there may be misalignment (or misalignment) between the individual color elements and the array of light receiving parts of the underlying solid-state image sensor.
This has the disadvantage that it tends to cause

Furthermore, the above is based on the fact that color elements (colored layers) dyed in different colors do not form a single layer but are composed of different layers, that is, form a multilayer structure. One method for eliminating or alleviating such drawbacks is described, for example, in US Pat. No. 4,236,098.
In this method, an array of color elements is formed in a single mordant layer. The dye is absorbed from the solution into the mordant layer through a window-like pattern using photoresist technology. Further, other methods for producing a multicolor optical filter consisting of a single-layer color element array are described in, for example, US Pat. No. 4,081,277 and US Pat. No. 4,168,448. In this method, heat sublimable dyes or heat transferable dyes are transferred into the dye-receiving layer through a window-like pattern of photoresist. However, even in these methods, it is necessary to repeat the steps of photoresist coating, development, peeling, etc. multiple times, which is still complicated, and there are many causes of low yield.

SUMMARY OF THE INVENTION Therefore, the first object of the present invention is to solve the above-mentioned drawbacks, to have a simple structure, a simple manufacturing process, and to increase the yield, so that it can be provided at low cost. The purpose of this invention is to clarify a polychromatic optical filter and its manufacturing method.

A second object of the present invention is to suppress the lateral diffusion of coloring substances in the color element receiving layer, so that each boundary between two or more coloring patterns having different colors is clear and color mixing is prevented. The purpose of the present invention is to clarify a polychromatic optical filter in which the optical density of each color element (coloring pattern) is sufficiently high without causing color formation, and a method for manufacturing the same.

Other objects of the invention will become apparent from the following description of the specification.

The object of the present invention is to provide a method for producing a multicolor optical filter, in which at least two colored patterns of different colors are formed on a color element receiving layer coated on a support. A heat-sensitive layer is applied on the applied color element receiving layer, and the color element receiving layer is partially exposed by irradiation with high-density energy radiation according to a pattern, and then the color element is applied. This is achieved by a method for producing a multicolor optical filter, which comprises a series of steps of applying a coloring substance to the exposed portion of the receptor layer to form a color pattern.

According to a preferred embodiment of the present invention, in the method for producing a polychromatic optical filter according to the present invention, the remaining heat-sensitive recording layer is removed each time after a series of steps, or the final step After the process, the remaining heat-sensitive recording layer is removed.

Furthermore, according to a typical embodiment of the present invention, a heat-sensitive recording material having a color element-receiving layer and a heat-sensitive recording layer coated on a support in sequence is irradiated with high-density energy radiation according to a first pattern, The colorability of the first color is improved by partially removing the heat-sensitive recording layer to partially expose the color element receiving layer, and then applying a first coloring substance to the exposed portion of the color element receiving layer. a step of forming a patterned portion, a step of removing the remaining heat-sensitive recording layer as necessary and then applying the heat-sensitive recording layer again, and irradiating high-density energy radiation according to a second pattern, The coloring property of the second color is improved by partially removing the heat-sensitive recording layer to partially expose the color element receiving layer, and then applying a second coloring substance to the exposed portion of the color element receiving layer. The step of forming a pattern part and, if necessary, the same steps as above to form a colored pattern part of the third color and thereafter are repeated, and the remaining heat-sensitive recording layer is removed after the final step. Therefore, the objective is to manufacture a polychromatic optical filter.

The present invention will be explained in detail below.

The polychromatic optical filter according to the present invention can be applied to a heat-sensitive recording material as shown in FIG.
0, on which a color element receiving layer 11 and a heat-sensitive recording layer 12 are coated. Note that FIGS. 1 and 2 are enlarged sectional views of essential parts schematically showing the method for manufacturing a polychromatic optical filter according to the present invention, and the dimensions such as film thickness are not practical.

When the support used in the present invention is used as a support for an optical filter, it needs to be transparent, but two or more colored patterns are formed in one color element receiving layer on the support. When transferring this onto another transparent support, the support does not need to be transparent since it is a temporary support, and may be translucent or opaque. . The support may also be in the form of a plate, a sheet, or a film. Examples of materials used for the support include plastics such as polyethylene terephthalate, polystyrene, polycarbonate, and cellulose acetate, glass, quartz, and sapphire. Further, the support itself may have other uses, for example as a face plate of an image pickup tube.

In the present invention, an undercoat layer may be coated on the support 10 before the color element receiving layer 11 is coated (not shown). The subbing layer is a layer of material that exhibits strong adhesion to both the support 10 and the color element receiving layer 11. Examples of substances used in the undercoat layer include gelatin, albumin, casein, cellulose derivatives, starch derivatives, sodium alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid copolymers, polyacrylamide, and the like. The thickness of the undercoat layer is desirably as small as possible, and is in the range of 0.01 to 1μ, preferably 0.05 to 0.5μ.

In the present invention, the color element-receiving layer is provided with a coloring substance, such as a dye. According to a preferred embodiment of the invention, the color element receiving layer 11 is a mordant layer dyed from a dye solution through a mask formed on the heat-sensitive recording layer 12. As this mordant layer, a layer made of polyvinyl alcohol, gelatin, etc. may be used. However, in this case, the amount of dye dyeing is small, and therefore it is difficult to obtain a sufficient optical density.At the same time, the movement of the dye in the mordant layer is relatively free; ) may have the disadvantage of blurring, blurring, and mixing of colors. This drawback can be overcome by including in the mordant layer a substance (called a mordant) that can relatively strongly fix the dye through adsorption, chemical bonding, or the like. In the present invention, such substances that are advantageously used in the heat-sensitive recording material include:
For example, JP-A No. 54-124726, JP-A No. 55-22766,
No. 52-45327, No. 52-136626, No. 53-30328,
Examples include substances described in publications such as No. 50-47624, No. 47-13935, and No. 51-73440.
Specific examples of mordants particularly advantageously used in the present invention include those represented by the following general formulas () and (). However, the general formulas () and () do not limit the mordants that are advantageously used in the present invention.

General formula () [wherein A is a monomer unit containing at least two ethylenically unsaturated groups, and B is a monomer unit containing α, β-
It is an ethylenically unsaturated monomer unit, and R is a hydrogen atom, a methyl group, or an ethyl group. Also x,
y and z indicate the molar ratio, x:y:z=0~
5:0-90:10-100. ] General formula () [In the formula, A is a unit of a copolymerizable monomer having at least two ethylenically unsaturated groups, B is a unit of a copolymerizable α,β-ethylenically unsaturated monomer,
R ₁ represents a hydrogen atom or a methyl group, R ₂ and R ₃ each represent a lower alkyl group, R ₄ represents an alkyl group, an aralkyl group, a cycloalkyl group, or a cycloalkylalkyl group, and X represents an anion;
x, y, z are molar ratios, x:y:z=0.5~
6.0:0 to 79.5:20 to 99.5] In a preferred embodiment of the present invention, for example, the following general formula (a) in the above general formula ()
A polymeric substance represented by the above formula is used together with gelatin to form a mordant layer.

General formula (a) [However, x:y:z is, for example, 4:48:48] The mordant layer is preferably as thin as possible as long as sufficient optical density of the desired color can be obtained. A mordant layer thickness of 0.3μ to 10μ gives satisfactory results in the present invention.

The heat-sensitive recording layer of the heat-sensitive recording material used in the present invention can be so-called fenestrated in a desired pattern by irradiating it with laser light or other high-density energy radiation, and can be coated with a coloring substance. In the dyeing process for imparting color, the film has a property that coloring substances such as dyes cannot pass through the film of the heat-sensitive recording layer.

As a heat-sensitive recording layer that can be opened in a desired pattern by irradiation with laser light or other high-density energy radiation, for example,
The heat-sensitive recording layers described in Publications No. 26929, No. 46-3710, No. 51-35144, etc. can be applied. However, these known heat-sensitive recording layers do not necessarily satisfy the property that dyes and the like cannot pass through the film.

In the present invention, the heat-sensitive recording layer contains at least one substance that can absorb high-density energy radiation such as laser light and efficiently convert this radiation energy into heat. Examples of such substances include carbon black,
graphite, heavy metal oxides or sulfides,
Especially manganese, or lead with an atomic weight of 45 to 210
Examples thereof include oxides or sulfides of heavy metals having , or these heavy metals themselves in a fine particle state, such as silver, bismuth, lead, iron, cobalt, nickel, etc., organic pigments such as phthalocyanine and rhodamine, or dyes.

Furthermore, the heat-sensitive recording layer of the present invention has a property of blocking the passage of the dye during the dyeing process of imparting a coloring substance, and is converted by the above-mentioned substances when irradiated with high-density energy radiation. It may contain a substance that evaporates or scatters in response to applied heat.

Examples of such substances include polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylonitrile, acetylcelluloses, nitrocelluloses, and the like.

According to a preferred embodiment of the present invention,
The heat-sensitive recording layer is formed by overcoating the mordant layer with a solution in which carbon black (for example, weight ratio to nitrocellulose is 1/4 to 2) is dispersed in an ethyl acetate solution of nitrocellulose, and the ethyl acetate is removed by evaporation. formed by.

Next, the method for manufacturing a polychromatic optical filter according to the present invention will be explained in more detail based on the drawings.

FIG. 1 shows an embodiment of the present invention.
A mordant layer 11 as a color element receiving layer of the present invention is coated on the support 10 in 1a, and a heat-sensitive recording layer 12 is further overcoated thereon in 1b.
By irradiating this heat-sensitive recording material with high-density energy radiation, the heat-sensitive recording layer 12 as shown in 1c is
is partially removed to partially expose the mordant layer 11.

In the present invention, examples of high-density energy radiation include argon gas laser, helium-
Examples include laser light such as neon laser. When irradiating the laser beam, it can be irradiated from the side of the support 10 in FIG. 1b or from the side of the heat-sensitive recording layer 12. When laser light is irradiated, if it is scanned over the heat-sensitive recording material as continuous light,
It is possible to form fine grooves in the heat-sensitive recording layer,
This is particularly advantageous, for example, when producing striped polychromatic optical filters.

Furthermore, in the case of manufacturing a mosaic-shaped polychromatic optical filter, the heat-sensitive recording material may be scanned with intermittent laser light. Intermittent irradiation in this case can be carried out, for example, by providing an intermittent shutter mechanism controlled in accordance with the scanning speed in the optical path between the laser light source and the heat-sensitive recording material.

In another method, the laser light source may be used to emit pulsed light.

It is of course possible to irradiate the heat-sensitive recording material with laser light through a mask with a desired pattern placed in the optical path.

Next, as shown in 1d of FIG. 1, the first color is dyed. According to one preferred embodiment, a heat-sensitive recording material as schematically represented in 1c:
It can be placed under a sublimable dye atmosphere, under vacuum evaporation of a dye, or immersed in a dye bath in which a dye is dissolved. In this case, for example, dyes known for dyeing textiles or dyes widely known in the photographic industry can be used. In one specific example, an alkaline (0.01N potassium hydroxide) aqueous solution containing 0.2% of the following cyan dye is used as a dyeing bath, and
A good dyed portion 13 can be obtained by the immersion treatment for 1 minute.

[Cyan dye]

Next, as shown in 1e, the remaining heat-sensitive recording layer 12 is peeled off in a solvent or the like. 1 more
As shown in f, a new heat-sensitive recording layer 12' is applied. The second and subsequent laser beam irradiations are carried out, for example, at 1 g, avoiding the previously dyed areas to partially remove the heat-sensitive recording layer.

As shown in 1h, perform the second color staining,
A dyed portion 14 is formed. In one specific example, an alkaline (0.1N potassium hydroxide) aqueous solution containing 0.2% of the following yellow dye was used as a dyeing bath at room temperature.
Perform the soaking process for 1 minute.

[Yellow pigment] Subsequently, the remaining heat-sensitive recording layer 12' is peeled off (see 1i), a new heat-sensitive recording layer 12'' is applied (see 1j), and a laser beam is irradiated (see 1k) to apply the third color. Dyeing area 1
5 and the last remaining thermosensitive recording layer 1
2'' is peeled off. After this, a protective layer (not shown) can be coated on the mordant layer 11, if necessary.

In one specific example of the third color dyeing process, the dyeing bath is an alkaline (0.01N potassium hydroxide) aqueous solution containing 0.2% of the magenta dye shown below, and the process is carried out at room temperature for 1 minute.

[Magenta pigment]

According to the method for manufacturing a multicolor optical filter according to the present invention, the heat-sensitive recording layer functions as a dyeing mask, as can be seen from the above embodiment. Further, when forming this mask, unlike in the case of a dyeing mask made from a photoresist layer, which is frequently used in the manufacturing method of conventional multicolor optical filters, a development process is not required.

In conventional methods of making dyed masks from photoresist layers, the following points were often pointed out. That is, firstly, when pattern exposure is performed on the photoresist, in order to increase the resolution, and also to remove the photoresist after development so that no photoresist film remains in the area where the window is to be opened. Careful attention must be paid to the amount of exposure. Second, so-called cracks may occur in the photoresist layer during the photoresist development process, and the photoresist layer may no longer function as a dyeing mask. Thirdly, related to the first and second problems above, special techniques are required to control the hardness of the mordant layer film and the adhesive strength between the mordant layer and the photoresist layer. It is to be.

While the conventional method for manufacturing a polychromatic optical filter had the above-mentioned problems, the polychromatic optical filter and method for manufacturing the same according to the present invention do not have any of the above-mentioned problems.

Furthermore, in the case of a conventional dyeing mask made of a photoresist layer, it is necessary to peel off the photoresist layer after the dyeing process of the first color and after the dyeing process of the second color. On the other hand, in the method for manufacturing a multicolor optical filter of the present invention, the heat-sensitive recording layer as a dyeing mask is used for the first color and the second color.
It is not necessarily necessary to peel off and remove after the dyeing process before the final process such as coloring. An example of this case is shown in the second
This will be explained based on the diagram. First, the color element receiving layer (mordant layer) 21 is coated on the surface of the support 20 (2a
(see 2b), and then overcoat the thermosensitive recording layer 22 thereon (see 2b). As shown in 2c, a part of the heat-sensitive recording layer 22 is removed by irradiation with high-density energy light such as a laser beam to expose a part of the color element receiving layer, and then a dyeing process is performed to dye the first color. A dyed portion 23 is formed (see 2d).
Next, a heat-sensitive recording layer 22' is overcoated (see 2e), and laser light is irradiated (see 2f).
A dyed portion 24 of the second color is formed (see 2g).
Furthermore, a heat-sensitive recording layer 22'' is applied (see 2h),
Laser light is irradiated (see 2i) to form a dyed portion 25 of the third color (see 2j), and finally the remaining heat-sensitive recording layer 22+22'+22'' is peeled off and removed.After this, as necessary Protective layer (not shown)
can be overcoated.

The present invention will be illustrated below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 A heat-sensitive recording material was prepared by sequentially coating the following layers (1) and (2) on a transparent glass plate.

Layer (1): Color element receiving layer containing a polymer represented by the general formula (a) (7.5 mg/100 cm ² ) and formaldehyde-hardened gelatin (15 mg/100 cm ² ).

Layer (2); thermosensitive recording layer with nitrocellulose (31.5 mg/100 cm ² ) and carbon black (31.5 mg/100 cm ² ).

Argon laser beam (wavelength 514.5nm, beam diameter 10μ) is applied to the sample of the above heat-sensitive recording material from the glass side.
The thermosensitive recording layer was removed in stripes by scanning irradiation at an energy density of 1.6 Joule/cm ² to expose the color element receiving layer. At this time, the distance between the linear portions scanned by the laser beam was set to 20μ.

Next, a sample of this heat-sensitive recording material was immersed in the following dye solution [A] at 80° C. for 20 seconds to dye the exposed portion of the color element receiving layer.

Dye solution [A] Suminol Milling Red RS 1% Glacial acetic acid 2.5% Next, after briefly washing with water and drying, the following layer (3) was coated on the layer (2).

Layer (3); layer with nitrocellulose (15 mg/100 cm ² ) and carbon black (15 mg/100 cm ² ).

Argon laser light was applied to the area adjacent to the red-dyed filament area of this heat-sensitive recording material sample at an energy density of 1.8 joules/hour in the same manner as above.
Irradiated at ^cm2 .

Next, this heat-sensitive recording material sample was immersed in the following dye solution [B] at 70° C. for 30 seconds to dye the exposed portion of the color element receiving layer green.

Dye solution [B] Acid green CI7 0.83% Direct yellow CI4 0.32% Glacial acetic acid 2.5% After washing with water and drying, a layer consisting of the same composition as layer (3) was further overcoated. Next, the unstained area was irradiated with argon laser light at an energy density of 2.1 Joule/cm ² in the same manner as described above.

Next, a sample of this heat-sensitive recording material was immersed in the following dye solution [C] at 70° C. for 20 seconds to dye the exposed portion of the color element receiving layer blue.

Dye solution [C] Direct Sky Blue 6B 1% Glacial acetic acid 2.5% Next, after washing with water, the heat-sensitive recording layer was removed using acetone.

In the manner described above, a striped multicolor optical filter consisting of three colors, red, green, and blue, was manufactured.

Example 2 A striped multicolor optical filter was manufactured by a method that differed from Example 1 only in the following steps. That is, in the case of this example, after each step of the red dyeing process and the green dyeing process, the remaining heat-sensitive recording layer was removed using acetone, and the process of Example -
A layer identical to layer 1 (2) was coated on top of the color element receiving layer. In the laser light irradiation step performed prior to the green dyeing step and the blue dyeing step, the irradiation energy density was set to 1.6 Joule/cm ² .

In this example, an attempt was made to manufacture a multicolor optical filter by recoating the heat-sensitive recording layer after each dyeing step, but a high-quality filter was obtained as in Example-1.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the method for manufacturing a polychromatic optical filter according to the present invention, and shows 1a to 1b.
1c to 1e show the formation process of the dyed part of the first color, 1f to 1i show the formation process of the dyed part of the second color, and 1j to 1m show the structure of the heat-sensitive recording material used in the present invention. Each of the steps for forming the third color dyed portion is shown. FIG. 2 shows another embodiment of the method for manufacturing a multicolor optical filter according to the present invention, in which 2a and 2b show the structure of the heat-sensitive recording material, and 2c and 2d show the dyed portions of the first color. 2e to 2g show the formation process of the dyed part of the second color, 2h to 2j show the formation process of the dyed part of the third color, and 2k shows the process of forming the dyed part of the thermosensitive recording layer after peeling and removal. The following shows how each case was handled. In the figure, 10 and 20 are supports, 11 and 21 are color element receiving layers, and 12 and 22 are heat-sensitive recording layers.

Claims (1)

[Claims] 1. A method for producing a multicolor optical filter in which at least two colored patterns of different colors are formed on a color element-receiving layer coated on a support, in which the color elements coated on a support are provided. A heat-sensitive layer is applied on the receptor layer, and the color element receptor layer is partially exposed by patternwise irradiation with high-density energy radiation, and then the exposed portions of the color element receptor layer are exposed. A method for manufacturing a multicolor optical filter, comprising a series of steps of applying a coloring substance to form a coloring pattern.