JPS5879205A - Production of filter for color separation - Google Patents

Abstract

PURPOSE:To prevent thermal decomposition of coloring matter with respect to a filter used for color television cameras, etc. by using coloring matter such as dyes or dyeing pigments and dropping the same by each small quantity onto a heater to evaporate the coloring matter instantaneously, thereby vapor depositing colored parts. CONSTITUTION:Dyeing pigments 1 of a magenta dye are charged into a hopper 5. A vibrator 2 and a belt 3 are disposed on the lower side of the hopper 5 and are operated cooperatively to drop the pigments 1 by each small quantity. Thereafter the pigments 1 are dropped by each small quantity onto a boat- like heater 4 which is heated to the vapor deposition temp. near the melting point of the pigments 1 at which no thermal decomposition occurs to evaporate the pigments instantaneously, thereby vapor depositing colored patterns while preventing thermal decomposition. A series of such stages are executed in a vacuum device. Thus the good filter for color separation free from blurring, out of focus and mixed colors in colored pattern parts is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a color separation filter used in color television cameras and the like.

As a color filter for color separation, a nine-segment filter is used that utilizes the interference effect of a transparent haze-electrode multilayer thin film.
Interference filters are broadly divided into dye filters 1 and 1, which are composed of colored layers of dyes and pigments arranged in a predetermined pattern (for example, striped or mosaic).Interference filters have a multilayer structure and have predetermined spectral characteristics Materials used (refractive index>'vc
There are many problems in manufacturing, such as adjusting the thickness of the film, laminating the film, and maintaining it. In particular, it is often difficult to control these when performing fine butterning.

In addition, many methods have recently been proposed for dye filters, such as gelate/casein, glycol, or polyvinyl alcohol on a transparent substrate.

A known method is to provide a mordant layer made of a synthetic polymer material such as silica or the like, and to color the mordant layer in accordance with a predetermined pattern. Coloring can be done by immersing the part in a dyeing bath in which a suitable dye is dissolved, or by bringing a sublimable dye close to or in contact with the part to be colored.
A method of thermal transfer by heating the dye can be mentioned. Also known is a method in which a filter is formed by vacuum-depositing a dye that has a low vapor pressure and is difficult to thermally decompose onto a substrate, and then etching it into a predetermined pattern.

Among these methods, the dyeing method has the advantage of being able to use and produce a large number of dyes, and the spectral characteristics required for filters can be met with K more than any other method. A wet method of immersion in a bath is used to dye each color according to a predetermined pattern.In the process, a dye-resistant mask using photoresist must be created and peeled off for each color dyeing process. Therefore, the yield is low and it is not an appropriate method for manufacturing inexpensive color filters. Furthermore, in terms of performance as a filter, color mixing such as color bleeding and "blurring" occurs at the buttering boundary, making it unsuitable for use in fields where high precision is required.

On the other hand, color filters created by the thermal transfer method or vapor deposition method are formed by a dry process such as heating or vacuum evaporation to form color filter elements having a predetermined pattern arrangement. It has the advantage that color mixing phenomena such as "bleeding" or "blurring" of colors at the border of buttering, which is glossed by color filters, are not observed, but when dyes and pigments are heated and vapor-deposited, , dyes and pigments are easily thermally decomposed, and if thermally decomposed products are also deposited at the same time, it will have a negative effect on the optical properties of the deposited film.That is, the dyes and pigments are filled into a deposition board, and the deposition boat is heated. However, dyes and pigments are evaporated, but they are organic compounds, have low conductivity, and are easily thermally decomposed, so dyes and pigments in contact with the walls of the evaporation boat are easily overheated above their melting point and thermally decomposed. SUMMARY OF THE INVENTION The main object of the present invention is to provide a method for manufacturing a color separation filter that can form colored portions of a filter while minimizing thermal decomposition of deposited dyes and pigments.

The method for producing a color separation filter according to the present invention is characterized by dropping dyes or pigments (dyes and pigments) in small quantities onto a heater and instantaneously evaporating them to perform color separation and form colored portions of the filter. That is, the present invention prevents the dye/pigment from being excessively heated by dropping the dye/pigment in small quantities onto a heater and evaporating it instantaneously. 1i%m is shown in Fig. 1. #i The dye and pigment 1 to be deposited is stored in the collar 5 as shown in Fig. 1, and is conveyed little by little from the hopper in conjunction with the vibrator 2. It is dropped onto the belt 3 and supplied onto the boat-shaped heater 4.

At this time, the boat-shaped heater (an aluminum crucible or the like may be used) is dyed near the melting point of the dye and pigment.

Example Rhodamine 6G, a xanthine-based magenta dye, was used as a dye that is easily thermally decomposed using a vacuum degree of 8X according to a conventional method.
10-"torr deposition temperature 170t'-230℃, film formation rate is 101' while controlling non-toxic
sec ~ 40 L'sec while adjusting 3000X
+7) The film was formed to a thickness of 7).

Next, according to the method of the present invention, the degree of vacuum is the same 8×10″t
The deposition temperature was kept at 210°C at 25°C because the 9°C is an important factor that controls the film formation rate.
The speed was set to L/IB66, and a film was formed to a thickness of 3000λ.

A conventional method using Rhodamine 6G (CI45160) and the method of the present invention will be compared. In the case of Rhodamine 6G, when the ester group in the side chain of the hexa/tene ring is thermally decomposed, it forms a lactone ring.When we conducted an infrared absorption spectrum analysis of the evaporated film, we found that the production rate of the lactone ring ( In other words, when comparing the conventional method and the method of the present invention, it is possible to know the degree of thermal decomposition).
00m'+Lotc150cDa") Rice! iot
n1760Cm=/(tofB1760Cts″+to
It was recognized that fC15000s= ).

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of a vapor deposition apparatus used to carry out the manufacturing method according to the present invention. 1-... 8 dyes, 2... pie bray? 9 ter, 3...
・Be/I/), 4... Boat-shaped heater, 5... Hopper. v-door

Claims (1)

[Claims] (1) A method for manufacturing a color separation filter, which involves dropping a small amount of dye or pigment onto a heater and instantaneously evaporating it to form a colored portion of the color separation filter.