JPS5832447B2 - Manufacturing method of image pickup tube face plate with built-in filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an image pickup tube face plate with a built-in filter that is most suitable for a small color television camera.

Generally, there are two main methods for incorporating a color separation line filter into an image pickup tube surface plate.

The first method is mainly used when incorporating an organic color separation line filter or the like, and as shown in FIG. 1, a glass substrate 1 on which at least one type of color separation line filter 12 is formed
1 and a thin glass plate 15 on which a transparent electrode 13 and a photoconductive film 14 are formed are glued together using an adhesive 16.The second method is to use an inorganic dichroic color separation line with excellent heat resistance and fading resistance. A glass thin film 23 is coated mainly by sputter deposition on a glass substrate 21, which is used when incorporating a striped filter, and has at least one type of color separation striped filter 22 formed thereon as shown in FIG. In this method, after the surface is smoothed by a method, a transparent electrode 24 is formed by a vapor deposition method, a spray method, etc., and a photoconductive film 25 is formed.

The present invention relates to the latter manufacturing method, and the spectral characteristics of the color separation line filter change in the glass thin film coating step.

Particularly, the occurrence of ripples and a decrease in transmittance can be mentioned, but as a color camera, these appear as a decrease in light utilization efficiency, uneven color mixing between two screens, and the like.

The former type of ripple generation can be reduced by consideration during initial filter design, but the latter type of decrease in transmittance that exceeds expectations at the time of design is largely influenced by manufacturing conditions.

Therefore, an object of the present invention is to provide a method for manufacturing an image pickup tube face plate with a built-in filter that causes less decrease in transmittance.

This embodiment will be described below by taking an SIO2-T r 02 system cyan filter as an example.

Dichroic filters are deposited using an electron beam evaporator, and after forming a lift material such as Cu or Ag on a transparent substrate in a pattern opposite to the filter pattern, the substrate temperature is raised to 150°C or higher. 4
．． S t 02 and T t 02 are alternately deposited in an oxygen atmosphere of 0×10′-5 to 1.5×10”-4 Torr.

The lift material is then removed by etching.

On the other hand, in the process of forming a glass thin film on a glass substrate on which a filter has been formed, a magnetron-type high-frequency sputter deposition device is used, which causes a small rise in substrate temperature, and a glass substrate of the same quality as the filter deposition substrate is used as a target. there was.

In the process of vapor deposition of this glass thin film, the distance between the electrodes provided on the target and the electrodes provided on the substrate holder is 55 m@, the sputtering gas Ar + 10% 02°, the substrate preheating is 130°C, and the input power is 600W. As a result, a glass thin film with strong adhesion can be efficiently obtained.

FIG. 3 shows the change in substrate surface temperature during glass thin film deposition.

As is clear from FIG. 3, when vapor deposition is performed with a power of 600 W, the surface temperature rises rapidly when the shutter is opened, reaches 250° C. after about 5 minutes, and then rises to about 300 to 350° C.

At this time, the temperature rise can be reduced by water-cooling the substrate holder, but the glass thin film obtained by water-cooling has large internal strains and poor heat resistance.

On the other hand, a glass thin film obtained at a high substrate temperature has excellent heat resistance and can withstand a temperature rise of 300 to 550° C. during the formation of a transparent electrode or photoconductive film formation process.

By the way, it has been found that during the step of forming the dichroic filter on a substrate, when the filter is formed under conditions where the substrate temperature is 300° C. or lower, the transmittance decreases significantly during the glass thin film coating step.

This situation is shown in FIG. In this way, when the substrate temperature is low during filter formation, there is no problem with the above-mentioned method of bonding the substrate on which the filter is formed and the glass thin film with an adhesive, etc., but the glass thin film according to the present invention is formed by vapor deposition. In this method, the transmittance decreases significantly and high image quality cannot be obtained.

In order to avoid an increase in the substrate temperature during the formation of the glass thin film, sputter deposition was performed at an even lower power of 200 W as shown in Figure 3, but the actual surface temperature was 170°C.
It doesn't get low enough.

As shown in Figure 4, when the substrate temperature during filter formation is 260°C, the transmittance is almost close to the theoretically calculated transmittance.
It can be seen that in the case of 0'C, the transmittance is still significantly reduced.

Also S i02. A substrate temperature of 300° C. or higher during filter formation using T i02 has the advantage that there is little decrease in transmittance and that an overcoat film with strong adhesion strength can be efficiently adhered with high power.

The above has described an example of a cyan filter using S 102TiO2, but the same applies to a yellow filter.

Similar results were also obtained for the dichroic filter made of MgF2-CeO2.

As described above, the manufacturing method according to the present invention is a method for manufacturing a filter-embedded image pickup tube picture plate in which a gicroic stripe filter is coated with a glass thin film by vapor deposition and the surface is smoothed by polishing. of,
This is a method for manufacturing an image pickup tube face plate with a built-in filter that is suitable for a high-quality simple color camera, which has a high light utilization efficiency and less unevenness in color mixing on two screens, by raising the temperature of the substrate surface higher than the substrate surface temperature during the glass thin film coating process. .

[Brief explanation of drawings]

Figure 1 is a diagram showing a method for manufacturing an image pickup tube face plate with a built-in filter such as an organic filter, Figure 2 is a diagram showing a manufacturing method of an image pickup tube face plate with a built-in filter such as a dichroic filter, and Figure 3 is a diagram showing a method for manufacturing a camera tube face plate with a built-in filter such as a dichroic filter. FIG. 4 is a diagram showing changes in substrate surface temperature, and FIG. 4 is a diagram showing changes in transmittance reduction during the glass thin film coating process depending on filter deposition substrate temperature. 21... Transparent substrate, 22... Stripe filter, 23... Glass thin film, 24...
...Transparent electrode, 25...Photoconductive film.

Claims (1)

[Scope of Claims] 1. A method comprising the steps of forming a color-separating striped filter on a light-transmitting substrate, and forming a glass thin film on the color-separating striped filter and the light-transmitting substrate by vapor deposition, A method of manufacturing an imaging tube face plate with a built-in filter, characterized in that the temperature of the substrate during formation of the color separation line filter is higher than the surface temperature of the substrate during deposition of the glass thin film. 2. The image pickup tube face plate with a built-in filter according to claim 1, wherein the color separation line filter contains SiO2 and TiO2, and the substrate temperature is maintained at 300° C. or higher when forming the filter. manufacturing method.