JPS60186585A - Fluorescent screen for color display crt - Google Patents

Abstract

PURPOSE:The titled fluorescent screen emitting monochrom beams of light blue which is prepared by mixing 3 different kinds of specific fluorescent substances wherein manganese, arsenic-activated zinc silicate is made largest in its particle sizes on the average, thus showing high uniformity. CONSTITUTION:A mixture of (A) Ag-activated zinc sulfide or Ag, GA-activated zinc sulfide, (B) Mn-activated zinc phosphate and (C) Mn, As-activated zinc silicate are used to give a fluorescent screen of light blue emission by the slurry method. The average particle is preferably 5.0-6.5mu in component A, 5.0-6.5mu in B and 5.5-7.0 in C.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field The present invention relates to a fluorescent surface of a polar ray tube for color display.

(2) Prior Art In recent years, with the spread of computers, cathode ray tubes for color displays have come to be widely used as terminal devices for computers. 7 A high resolution tube with a smaller hole pitch than the Yado mask, a super sieve resolution tube, has been put into practical use, making it possible to display high f'L density. As for these fluorescent surfaces,
Depending on the application, physical properties may be different from those for conventional commercial TV use.
ing. That is, in order to perform high-density display, it is necessary to increase the number of scanning lines, and at that moment, the horizontal scanning frequency must be increased or the frame frequency must be increased or decreased. Increasing the horizontal scanning frequency increases the load on the module circuit, so the frame frequency is increased or decreased. In this case, the P22 phosphor in the US has a short afterglow time, so the flicker becomes noticeable. As a countermeasure to this, a manganese-arsenic activated zinc silicate P39 phosphor with a long afterglow time and a manganese-activated zinc phosphate P27 phosphor are used for green and red VC. Also, to prevent eye fatigue, use silver-activated zinc sulfide phosphor or silver-activated zinc sulfide phosphor, P39 phosphor, P27 phosphor.

They are mixed to give a light blue color and to increase the brightness.

Currently, a slurry method is generally used as a method for forming such a three-color light emitting layer. The fluorescent substance ffi is suspended in a mixed solution of polyvinyl alcohol (PVA) and ammonium oxide (Al)C) to form a slurry.
Apply an excessive amount of Rose 1 No. with the inner surface of the channel facing upwards, shake off the slurry with high speed rotation, dry with an infrared magnetic heater, remove iron scraps from the shadow mask, and perform a irradiation with a high-pressure mercury lamp, followed by hot water. It is developed to form a phosphor dot.

When a light blue light-emitting element is made by mixing a silver activated zinc sulfide phosphor or a silver gallium activated zinc sulfide phosphor with a P39 phosphor and a P27 phosphor using this slurry method, 3
The ratio of different types of phosphor differs between the center of the panel and the periphery of the panel, resulting in a frequent drawback that the emitted light color differs between the center and the periphery of the panel. Therefore, the color uniformity of the light blue color is poor, and the three light emitting elements of green, red, and light blue are activated to produce white? When used, the disadvantage was that the uniformity of the white was also very poor.

(3) Purpose of the Invention The present invention aims at keeping the mixing ratio of the three types of phosphors constant between the center and the periphery of the channel when making a light blue light emitting element by mixing these three types of phosphors. , the color around the center 8 of the Tsukuneru is made the same to obtain color uniformity with a single light blue color/
) L is to provide a fluorescent surface gold.

(4) Description of Examples A phosphor is suspended in a bath solution of PVA and ADC to form a slurry, and this slurry is applied excessively to the inner surface of the flask and shaken at a constant rotation speed to form a fluorescent film. In the case of
The film thickness at the periphery of the panel is generally smaller than that at the center of the panel, although it depends on the time of the pot. At this time, even if these conditions are constant, the film thickness distribution of the rainbow phosphor differs between the phosphors. When we investigated the film thickness distribution of the silver-activated zinc sulfide phosphor, the silver-gallium-activated zinc sulfide phosphor, the P39 phosphor, and the P27 phosphor that make up the light blue color, we found that they had the same average particle size. It was found that the P39 phosphor has a higher film thickness at the periphery of the panel than at the center of the panel compared to other phosphors. Therefore, when three phosphors having the same average particle size are mixed and a light blue phosphor element is formed by a slurry method, the periphery of the panel becomes fringed. This is P39 The phosphor has the best crystalline shape on the back of the 3-ume phosphor, so it is thought that this is because the phosphor is easiest to move when it is shaken off at high speed. As a way to solve this problem, if the average particle size of the P39 phosphor is also larger than the average particle size of the silver-activated zinc sulfide phosphor or the gallium-activated zinc sulfide phosphor and the P27 phosphor.
39 A large amount of phosphor settles in the center of the panel before it is rotated at high speed and then rotated at high speed to form a phosphor film. What is the ratio of 3 phosphors at the center and periphery of the panel? 1 was found to be the same. In particular, silver activated zinc sulfide phosphor, silver gallium activated zinc sulfide phosphor, P27 fluorescein average particle diameter t5
．． 0-6.5 μP39 fluorophoric material average particle size 5.5-7.
We have found a type of ink that gives the most detailed and uniform Ride Book color when the setting is 0μ. Examples are given below. Example 1 Silver-activated zinc sulfide phosphor with an average particle size of 5.5μ 35Ft amount%
, 35% P27 phosphor with an average particle size of 5.3μ.

Mixing 30 quintillion percent of P39 powder with an average particle size of 6.5μ,
A fluorescent film was formed using a slurry method. At this time, the CIE chromaticity at the center of the panel is X=0.205. Y=0.220 at the panel periphery X=0.205. Almost the same color tone was obtained when Y=g and 225, and a light blue color with good uniformity was obtained. The figure shows the phosphor particle size distribution; 3v curve 1 is silver-activated zinc sulfide phosphor, 2 is manganese-activated zinc phosphate phosphor,
3 is a manganese-arsenic activated zinc silicate phosphor.

Example 2 Silver, gallium activated zinc sulfide phosphor 5 with an average particle size of 6.0μ
30 quintillion% P27 phosphor with 0 weight percent and average particle size of 5.8μ
, 20% of P39 fluorophore with an average particle size of 7.0μ? I: Mixed and completely formed a fluorescent film using a slurry method. At this time, the CIE chromaticity at the center of the panel is X=0.180. Y=0, 185 In the peripheral area of the panel, X=0.177, Y=0.175, and a light blue color with excellent color uniformity was obtained.

(6) Effects of the invention In addition to the above-described features, the present invention includes a silver activated zinc sulfide phosphor or a silver gallium activated zinc sulfide phosphor and a P27 phosphor.
P39 When creating a light blue color by mixing phosphors, the color uniformity is very good, and not only the uniformity of light blue alone but also the uniformity of white color is significantly improved, so it is practical. Very useful.

[Brief explanation of the drawing]

The figure is a graph showing the phosphor particle size distribution of Examples.

Claims (2)

[Claims] (1) One of the light emitting elements of a cathode ray tube for a three-color color display is a silver-activated zinc sulfide phosphor, or a silver-gallium-activated zinc sulfide phosphor, a manganese-activated zinc phosphate phosphor, and manganese, arsenic. When forming a light blue color light-emitting device with a mixture of activated zinc silicate phosphors, the average particle size of the manganese arsenic activated zinc silicate phosphor is different from that of the silver activated zinc sulfide phosphor or the silver activated zinc sulfide phosphor. In addition, the average particle size of the gallium-activated zinc sulfide phosphor and the manganese-activated zinc phosphate phosphor was also increased to improve sexual characteristics and the fluorophore orientation of the penile tube for color disgracing. (2) The average particle size of the ffd silver-activated zinc sulfide phosphor or silver gallium-activated zinc sulfide phosphor is 5.0 to 6.5μ, and the average particle size of the manganese-activated phosphor V*lead phosphor. is 5.0-6.5
The average particle size of μ-Raman-activated zinc silicate phosphor is 5.5~
7.0μ/) A fluorescent surface of a cathode ray tube for color display according to claim (1).