JPS604585A - Color cathode ray tube responsive to light-pen - Google Patents

Abstract

PURPOSE:To provide a color cathode ray tube responsive to a light-pen, and furnished with a fluorescent panel composed of 3-color picture elements consisting of a mixture of a fluorescent material having long afterglow and a fluorescent material having extremely short afterglow and composed of Y2SiO5:Ce, Y3Al5O12:Ce, etc. according to the red, green or blue color to be displayed. CONSTITUTION:The objective color cathode ray tube is furnished with a fluorescent panel composed of red, green and blue-light emitting picture elements consisting of a mixture of (A) a fluorescent material having long afterglow, i.e. 10% extinction time of >=10m-sec and (B) a fluorescent material having extremely short afterglow, i.e. 10% extinction time of <=1mu-sec and composed of (i) Y3Al5O12:Ce and/or Y3(Al,Ga)5O12:Ce contained in the red and green elements and (ii) Y2SiO5:Ce contained in the blue element. EFFECT:The color reproducing range of the color CRT can be remarkably extended while retaining the light-pen respondence and the flicker characteristics of the conventional color CRT.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color cathode ray tube, and more particularly to a color cathode ray tube equipped with a fluorescent surface suitable for use with a light pen.

Recently, with the development of computer peripheral equipment, color cathode ray tubes, which were conventionally used only as display equipment, are now required to have light-bene sensitivity compatible with input/output to computers. However, the fluorescent surface of color cathode ray tubes for displays is usually 10% thicker in order to suppress flicker on the screen.
If the phosphor is composed of a phosphor with a long afterglow time of 10 milliseconds or more, the luminescence characteristics (2) of the phosphor tend to be delayed in response to electron beam stimulation (1), as shown in Figure 1. There is. Therefore, even if the light beam is used to detect the light emitted from the phosphor during the short period of several tens of nanoseconds when the electron beam stimulates the pixels on the phosphor surface, the light output is too weak to be detected. That is, there was a problem that there was no light pen sensitivity, and there was a drawback that the above requirements could not be satisfied.

Therefore, in order to compensate for this drawback, recently, Y2 SIOs: Ce or Y3 A t5 has been added to the long afterglow phosphor.
0Hz; Fluorescent surfaces mixed with ultra-short afterglow phosphors such as C6 have been developed. According to this phosphor surface, as shown in Fig. 1, the response characteristic (3) of the ultra-short afterglow phosphor to electron beam stimulation (1) K is very fast. Although pen sensitivity may be obtained, the screen has the advantage that flickering does not increase to the extent that it becomes a problem. On the contrary, there is a drawback that the color purity is reduced due to the emission color of the ultra-short afterglow phosphor, which is a mixture of the original emission colors of each pixel constituting the fluorescent surface.

This invention has been made to improve the conventional drawbacks, and provides a color cathode ray tube that minimizes deterioration in color purity and is equipped with a fluorescent surface that is sensitive to light pens. .

Figure 2 shows three main types of ultra-short afterglow phosphors with a 10% afterglow time of 1 microsecond or less, namely Y2S i 05
: Ce, Y2Al5O12: Ce and Yg
Curve (4) is the emission spectrum of Y2Si05HCe, curve (5) is the emission spectrum of Y3At50B:Ce, and curve (6) is the emission spectrum of Yg(At% Ga)sO+z:
The emission spectrum of Ce is shown.

As is clear from this figure, the luminescent color of Y2Si05HCe (curve (4)) is blue, and Yg A t50) 2
: Ce and Yg (At1G a ) sat 2
: Ce (that of the curve (41 (51) is yellow).

Therefore, by using these ultra-short afterglow phosphors for the three types of red, blue, and green pixels that make up the fluorescent surface of a color cathode ray tube, it is possible to reduce the color purity of the emitted light of each pixel. It is believed that the color reproduction range of color cathode ray tubes can be maximized by suppressing That is, Y2S i 06 for the blue pixel
: Ce, and Y, whose emission color is very similar to that of the green pixel.
3At50122CealsoViYsCAL,Ga)50
12: Ce and Y2, which has a similar luminescent color because no red-emitting ultra-short afterglow phosphor is known for the red pixel.
Al5O12: Cef or Yg (A4, Ga) 60
12: By using Ce, the color reproduction range can be greatly expanded compared to the conventional method in which the same ultra-shallow phosphor is used for all pixels. A more detailed explanation will be given below using examples.

<Example 1> As a long afterglow phosphor with a 10% afterglow time of 10 milliseconds or more, a ZnS:Ar:Pb phosphor was used for the blue pixel, and a Zn2Si04:Mn:As phosphor was used for the green pixel. The red pixel contains 20% Y2O2S:Eu phosphor (Zn
, MP)3(PO<): Equipped with an afterglow fluorescent surface using Mn phosphor. In order to make the color cathode ray tube sensitive to light pens, conventionally, each pixel was equipped with a Y2SiO5:Ce phosphor. 1
It contained 0% by weight. As a result, the six emitted colors of each pixel are:
Blue is x=0.150 7=0.060, green is X=0.1
95 y=0.660, red is x=0.611y=Q, 3
35, and the color reproduction range was the range surrounded by the triangle shown in (7) in FIG. However, only the ultrashort afterglow phosphor mixed into the blue pixel is Y, 5i0s:Ce (10
In the color cathode ray tube of the present invention, in which the ultra-short afterglow phosphor mixed in the green and red pixels is Y4Al2O92:Ce (10M amount%), the emitted color of each pixel is blue as x= o, 150 y= 0.060, green is x=o
, 205 y=0.675, red is x=o, 625 y=
0.340, the color reproduction range was improved to the range surrounded by the triangle shown in (8) in FIG.

<Example 2> ZnS:AJ phosphor (25% by weight), Zn
4Si04:Mn:As phosphor (30% by weight) and (
Zn%MY)! (PO4)z: Mn phosphor (
45% by weight) mixed phosphor (emission color is light blue),
In order to make the color cathode ray tube equipped with the afterglow fluorescent surface using the same phosphor as in Example 1 sensitive to a light pen for the green and red pixels, 5% by weight of Yg ( A
t1Ga) 5011; Ce ultra-short afterglow phosphor was mixed. At this time, the emission color of each pixel is blue, x=o, 23
0 y=0.240, green is x=0.200 y=o, 6
So, for red, x=0.630, y=0.340, and the color reproduction range was the range surrounded by triangle (9) in FIG.

However, Y2S
i 05: Ce, mix it into the red pixel and Yg
A t5012: In the color cathode ray tube equipped with the fluorescent surface of this invention changed to Ce, the emitted light color of each pixel is as follows: blue is x=0.2207=0.230, and green is x=0.20.
0 y=o, 680, and x=0.635 y=o
, a4o, the color reproduction range is expanded to the range surrounded by the triangle α0).

As detailed above, according to the present invention, the light pen sensitivity and flicker characteristics are improved compared to the conventional method in which light pen sensitivity was obtained by mixing an ultra-short afterglow phosphor only with a glaze. As it is, the color reproduction range of color cathode ray tubes can be greatly expanded, significantly increasing the product value.

Note that the above-mentioned long-lasting phosphor with a 10% afterglow time of 10 milliseconds or more does not necessarily have to be a single phosphor, but has the characteristics of a mixture of several types of phosphors. It is sufficient if the afterglow is 10 milliseconds or more.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the luminescence characteristics of a phosphor caused by electron beam stimulation.
Figure 2 shows the emission spectrum of the main ultra-short afterglow phosphor due to electron beam stimulation, and Figures 3 and 4 show the color reproduction range of the color cathode ray tube of this invention and the conventional color cathode ray tube. It is a diagram shown in comparison. +7) (91...triangle showing the color reproduction range of the conventional color cathode ray tube, (8) 10)...triangle showing the color reproduction range of the color cathode ray tube of the present invention. Agent Masuo Oiwa Figure 1 Figure 21”: 1 Wavelength (n 771) Figure 3 Figure 4 ■ 0 0.2 04 06

Claims (1)

[Claims] (Red, blue, etc. formed by a mixture of a long afterglow phosphor with a 10% afterglow time of 10 milliseconds or more and an ultra-short afterglow phosphor with a 10% afterglow time of 1 microsecond or less, In a color cathode ray tube equipped with a fluorescent surface composed of three types of green pixels, the ultra-short afterglow phosphor contained in the red and green pixels is Y.
3A1501B: Ce or Y3 (At, Ga) 60H
A light-bene sensitive color cathode ray tube characterized in that the ultra-short afterglow phosphor contained in the blue pixel is at least one of Y2S10s:Ce.