JPH0340453B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a transparent electrode formed on a color separation filter.

For example, various image pickup tubes for color televisions with built-in color filters have been proposed, and one example is as shown in FIG. A dichroic stripe filter 2 made of a multilayer film is formed by this method, and then a transparent electrode 3 made of, for example, tin oxide, indium oxide, etc. is formed by a method such as vapor deposition, sputtering, or CVD.
form. Next, a photoconductive film 4 made of a deposited film of Sb ₂ S ₃ or Se-As-Te is formed. Next, a glass tube 5 containing a previously prepared electron gun is joined. For this purpose, a soft metal 6 such as indium is used and bonded by cold compression bonding. As is clear from FIG. 1, the soft metal 6 is connected to a transparent electrode 3, whereby a signal current is extracted, and a metal ring 7 made of, for example, stainless steel, is placed outside the soft metal 6.
The image signal is sent to the television camera circuit through.

Further, to describe the conventional method in detail with respect to only the parts particularly related to the present invention, the dichroic stripe filter 2 formed on the transparent conductive substrate 1 is made of, for example, magnesium fluoride and cerium oxide, or titanium oxide and silicon oxide, etc. Generally, the thickness is 1 to 2 μm and the width is several μm to several tens of μm. Conventionally, the transparent electrode 3 was formed directly on the dichroic stripe filter 2, but when a film of tin oxide, indium oxide, etc. is formed by, for example, vapor deposition or sputtering, the thickness of the transparent electrode can be reduced to 500 mm. -3000A, the surface of the transparent electrode 3 was uneven because there was a difference in level between the part where the multilayer film of the dichroic stripe filter was present and the part where the multilayer film was not present. Therefore, since the photoconductive film 4 to be formed next is also formed by a vapor deposition method etc., there will be a difference in level.
There were many problems. Currently, many methods for forming photoconductive films have been developed, but in all of them, the thickness of the photoconductive film 4 is from several μm to several tens of μm, and when the photoconductive film 4 has a multilayer structure, The first layer of the photoconductive film 4 formed directly on the transparent electrode 3 is often a layer with a thickness of several hundred to several thousand amps, and is affected by the unevenness of the dichroic stripe filter 2 that appears on the transparent electrode 3. The conductive film 4 was not formed uniformly, which deteriorated the characteristics of the photoconductive film. That is, the edge portion of the photoconductive film 4 formed on the edge of the dichroic stripe filter has an extremely high dark current, which appears as linear scratches on the image, and furthermore, the structure of the photoconductive film 4 is disturbed. This causes an increase in dark current, a decrease in SN ratio, etc., and also significantly shortens the life of the photoconductive film 4.

In order to solve these shortcomings, the special public
According to Publication No. 31982, as shown in FIG. 2, for example, a transparent substrate 1 on which a dichroic stripe filter 2 is formed is coated with an epoxy adhesive or the like.
A resin that is liquid during operation and has sufficiently high light transmittance after curing and is chemically and vacuum stable is used to cover the irregularities of the dichroic stripe filter 2 and the areas without the filter 2 to a sufficient thickness, e.g.
The resin layer 8 is formed by coating to a thickness of 10 μm. Since it is in a liquid state during operation, it is said that it is possible to smooth out the unevenness of the dichroic stripe filter 2.

Furthermore, in this conventional method, a method has also been proposed in which, before the step of forming the transparent electrode 3, the transparent inorganic substance 9 is formed using, for example, silicon oxide or magnesium fluoride by vapor deposition or sputtering. (See Figure 3) However, in the method of this Japanese Patent Publication No. 55-31982, the dichroic stripe filter 2
Since the resin layer 8 formed thereon is liquid at the time of coating, it fills the recesses of the dichroic stripe filter 2. For example, as shown in FIG. Based on the relationship between the intermolecular forces of the resin materials used in the process and the relationship between the surface tension of the resin materials themselves, microscopic observation shows that the surface of the resin layer 8 has a spatial frequency that corresponds to the spatial frequency of the dichroic stripe filter 2, as shown in FIG. In many cases, matching unevenness is formed. Therefore, although the degree of unevenness of the dichroic stripe filter 2 before forming the resin layer 8 is improved, the transparent electrode 3 or the photoconductive film 4 is
is not necessarily sufficient. Therefore, in order to further improve the unevenness, it is necessary to greatly increase the thickness of the resin layer 8, as shown in FIG. In this case, considering the function of the color separation filter in the image pickup tube for color television, it is clear that significantly increasing the thickness of the resin layer 8 will impair its characteristics.

The present invention solves these problems and proposes a method for forming a transparent electrode that provides a highly accurate color television image when used in a color television image pickup tube. That is, the present invention
In a method of creating a transparent electrode on a color separation filter layer formed on one side of a transparent substrate via an intermediate smoothing layer, transparent light is applied to the color separation filter layer when forming the intermediate smoothing layer. A method for producing a transparent electrode, comprising the steps of forming a curable coating layer, exposing the photocurable coating layer to light from the transparent substrate side, and removing the uncured photocurable coating layer. It is.

The present invention will be described in detail below with reference to FIGS. 6 to 9 of the drawings. For example, as shown in FIG. 6, a dichroic stripe filter 2 is formed on a transparent substrate 1. The dichroic stripe filter 2 may of course be an organic stripe filter, which is formed by photo-etching a photosensitive gelatin, grue, etc. into stripes and then dyed with a predetermined dye. For example, a photocurable coating layer 10 is formed by coating the dichroic stripe filter 2 with a transparent photosensitive material, such as a photocurable material whose main material is gelatin or green. A spinner method is usually used for this application. After application, heat treatment is performed at around 100℃. The transparent and photosensitive coating layer 10 is, for example, a dichroic stripe filter 2 with unevenness.
Apply to a thickness that will approximately cover the area. In this state, as shown in FIG. 6, the surface of the coating layer 10 has irregularities corresponding to the spatial frequency of the dichroic stripe filter 2, as described above. Next, the transparent coating layer 10 is exposed to light to form an insoluble cured layer. In this exposure step, light is irradiated from the transparent substrate 1 side as shown in FIG.

An example of the relative spectral sensitivity of the transparent coating layer 10 is shown in FIG.
Its sensitivity region is mostly concentrated in the near-ultraviolet wavelength region of 400 μm. On the other hand, the spectral characteristics of the color separation filter can be set as required for both the dichroic stripe filter and the striped filter.
In the dichroic filter 2 shown in the figure, the first
For example, a cyan filter 2-1 as shown in FIG. 6 is formed for the color, and a similar yellow filter 2-2 is formed for the second color. In this state, as shown in FIG. 7, when light is irradiated from the transparent substrate 1 side using a commonly used ultra-high pressure mercury lamp, for example, as shown in FIG.
As can be easily estimated from the photosensitive area in Figure 0, in the area where the wavelength component of the photosensitive area of the photosensitizer hardly passes (i.e., the area where the filter 2 is present), the coating layer 10 is in an unexposed state, so that the It is dissolved and removed by a developer during the development process. On the other hand, the coating layer 10 formed on the portion of the photosensitive agent that allows most of the wavelengths in the photosensitive region to pass through (that is, the portion where the filter 2 is not present) is photocured and remains in that portion without being removed even after development. Therefore, as can be seen from FIGS. 6 and 7, if the thickness of the coating layer 10 is approximately equal to the height of the uneven steps of the dichroic stripe filter 2, for example, the initial thickness of the dichroic stripe filter 2 can be improved. The unevenness can be greatly improved. Of course, it is possible to directly form transparent electrodes on the color separation filter whose surface has been smoothed in this way, but if further surface smoothness is required, it can be finished as shown in Figure 8. A coat film 11 may also be formed. This finishing coat film 11 may be the above-mentioned transparent coating agent having photosensitivity. Of course, the light irradiation at this time is carried out from the surface of the photosensitive agent coated film. Furthermore, this finishing coat film 11 is not necessarily limited to photosensitive materials, and may be made of a wide range of materials, such as epoxy resins, acrylic resins, and other silicone resins, as long as they are optically transparent. . After forming the finishing coat film 11, a transparent electrode 3 and a photoconductive film 4 are formed as shown in FIG. 8, and the resulting color television image has a high quality image with less dark current and an improved signal-to-noise ratio. I can do it. Furthermore, according to the present invention described above, since the base of the transparent electrode 3 is an organic substance or contains an organic substance, in the case of a color television image pickup tube, for example, gas release from the organic substance causes a vacuum inside the tube. This may cause deterioration of the cathode incorporated in the electron gun or ion burns on the photoconductive film 4. Therefore, in order to improve these drawbacks, the present invention, as shown in FIG. 9, forms a transparent inorganic material 12 such as SiO ₂ or MgF ₂ by vapor deposition or sputtering before the transparent electrode forming step, and then forms a transparent electrode 3. You may.

Although the details of the present invention have been explained above, the present invention is a method for forming a transparent electrode on a transparent substrate on which a so-called color separation filter layer of a dichroic stripe filter or an organic stripe filter is formed. is applied to a thickness approximately equal to the dimension of the uneven steps of the color separation filter, and is cured by exposing it to light from the glass substrate side, and further forms a finishing coat film if necessary. Alternatively, a high quality color television image can be obtained by forming a transparent inorganic substance on the finished coat film in order to improve vacuum resistance.

Above, we have explained the method of forming transparent electrodes on a transparent substrate on which a color separation filter is formed regarding an image pickup tube for color television. There are many cases in which it is necessary to form transparent electrodes.

For example, optical color separation filters are often used to colorize the displays of color television receivers that use liquid crystals.
Furthermore, transparent electrodes are often used as electrodes for driving liquid crystals. Therefore, the present invention provides a method for forming transparent electrodes on a transparent substrate on which a color separation filter layer is formed when manufacturing color television receivers using liquid crystals or display panels that conventionally use cathode ray tubes. You can also get good results by using it. In particular, when patterning a transparent electrode by microfabrication, it is possible to obtain precision in terms of line width, etc. after microfabrication. Regarding the image pickup tube, although the photoconductive type image pickup tube has been described, the present invention is also applicable to an image pickup tube having an electron emitting surface. Furthermore, in imaging devices that use solid-state imaging devices such as CCDs and MOS, if the color separation filter layer is smoothed, the bonding process to the so-called silicon chip used in solid-state imaging devices can be performed smoothly, and the alignment of the color separation filter layer is smooth. High accuracy can be obtained, and the present invention can also be applied to these. As described above, the method for producing a transparent electrode of the present invention is extremely excellent in that it has a wide range of application and can achieve high precision and quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the vicinity of the photoconductive surface of an image pickup tube having a photoconductive surface incorporating a color separation filter, FIGS. 2 to 5 are sectional views showing examples of the conventional method, and FIG. - FIG. 9 is an explanatory cross-sectional view showing an example of the method for producing a transparent electrode of the present invention, and FIG.
It is a graph diagram showing the spectral characteristics of a filter layer and a photocurable coating layer. DESCRIPTION OF SYMBOLS 1... Transparent substrate, 2... Filter, 3... Transparent electrode, 4... Photoconductive film, 10... Photocurable coating layer, 11... Finishing code, 12... Transparent inorganic substance.

Claims (1)

[Claims] 1. In a method for forming a transparent electrode on a color separation filter layer formed on one side of a transparent substrate via an intermediate smoothing layer, the color separation filter layer is It is characterized by comprising a step of forming a transparent photocurable coating layer on the layer, a step of exposing the photocurable coating layer from the transparent substrate side, and a step of removing the uncured photocurable coating layer. A method for creating a transparent electrode. 2. The method for producing a transparent electrode according to claim 1, which includes the step of forming a transparent finishing coat film on a photocurable coating layer that has been cured by exposure from the transparent substrate side.