JPS61109244A - Beam index type cathode-ray tube - Google Patents

Abstract

PURPOSE:To obtain a picture image without cloudy colors, by furnishing a photoindex phosphor in which neighboring phosphors don't irradiate simultaneously or the photoindex phosphor exercises light absorbing function. CONSTITUTION:The strips of two color irradiating phosphors, neighboring with the stripe of a photoindex phosphor 4, are made of phosphors with an insensible or a dully sensitive phosphor to the light from the photoindex phosphor. And, phosphors 3B of blue color irradiating are avoided to place neighboring with the photoindex phosphor 4, but phosphors 3R and 3G of red and green colors irradiating are placed neighboring with the photoindex phosphor 4. In this case, as phosphors 3R and 3G, are used Y2O3:Eu red and ZnSiO3:Mn green, for example, which don't irradiate when receiving light from the photoindex phosphor. Therefore, when electron beams hit the photoindex phosphor, the neighboring phosphors don't irradiate simultaneously, and the index phosphor exercises light absorbing function, resulting in no mixture of cloudy colors.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a beam index type cathode ray tube, and more particularly to a cathode ray tube with improved color mixing.

Japanese Patent Application Laid-open No. 1983 (1983) as an example of a beam index type cathode ray tube
There is one disclosed in Japanese Patent No.-214253.

This will be explained with reference to FIG. In the figure, 1 is the face of the bulb, and the inner surface has phosphors 3G that emit light in three primary colors.
3R, 3B and light index phosphors 4 that emit invisible light with a short afterglow are regularly and repeatedly formed in a stripe pattern. That is, from the left side of the figure, a light absorption layer 5 in which a light absorber such as graphite is formed in a stripe shape, a green light emitting phosphor 3G, a light absorption layer 5, a red light emitting phosphor 3G, a light index phosphor 4, and a blue light emitting light absorbing layer 5. The phosphors 3B are repeatedly formed in stripes in this order. 6 shows a metal bank layer formed on the phosphor stripe.

In this cathode ray tube, a second light index phosphor 3G' is mixed with a green light emitting phosphor 3G, and index information is obtained from the two light index phosphors 4.3CG'.

Also, since this cathode ray tube is formed on the metal back layer 6 or the phosphor stripes, it is possible to obtain the optical index signal from the rear side of the bulb.The sensor (not shown) for obtaining the optical index signal is located on the bulb face. It is placed in front of 1. Furthermore, the optical index phosphor 4 acts as a light absorber for the adjacent phosphors 3G and 3B.
・ Mouth? By the way, this cathode ray tube had the following problems.

That is, ZnS:Cu, AI (green), Y
When 2O2S:Eu (red) and ZnS:Ag (blue) are used, the phosphors 3R are arranged on both sides of the optical index phosphor 4.

3B emits light by ultraviolet light emitted by the optical index phosphor 4, and the optical index phosphor 4 cannot function as a light absorber, resulting in color mixture.

. . The present invention was proposed in view of the above-mentioned problems, and the optical index phosphor stripe and two adjacent color emitting phosphor stripes are each replaced with a fluorescent material that is insensitive or has low sensitivity to the light emitted by the optical index phosphor. It is made up of the body and is designed to improve color mixing.

The present invention will be explained below with reference to FIG. In the figure, the third
The same reference numerals as those in the drawings indicate the same parts, and the explanation will be omitted. Fig. 3 The difference from the cathode ray tube is that the stripe of the optical index phosphor 4 and the two adjacent color emitting phosphor stripes are each composed of phosphors that are insensitive or have low sensitivity to the light emitted by the optical index phosphor. So far, ZnS: A has been used as a blue-emitting phosphor 3G.
Since it is difficult to obtain a phosphor with high emission brightness to replace phosphor g, the blue-emitting phosphor 3B is arranged not to be adjacent to the optical index phosphor 4, and the red- and green-emitting phosphors 3R are used.

3G is placed adjacent to the optical index phosphor 4. In this case, the phosphors 3R and 3G are Y2O3:Eu (red), Zn5iO3:Mn (green), etc., which do not emit light with the light emitted by the optical index phosphor.

As shown in Figure 3, the light is reflected from the surface of the bulb face 1 and reaches the phosphor 3B, which emits light due to the light emitted from the light index fluorescence, but the reflectance is small because it is reflected at the glass interface. , the luminescence level is extremely small and does not affect color mixing.

As described above, according to the present invention, when an electron beam hits an optical index phosphor, adjacent phosphors do not emit light at the same time, and the optical index phosphor acts as a light absorber, which prevents color mixture. No images can be obtained.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of the main part of a cathode ray tube showing an embodiment of the present invention, Fig. 2 is a side sectional view of the main part showing the path of light emitted by the cathode ray tube shown in Fig. 1, and Fig. 3 is a beam index type. FIG. 2 is a side sectional view of a main part of an example of a cathode ray tube. 1... Bulb, 3G, 3B, 3R... Phosphor that emits three primary colors, 4...
... Optical index phosphor, 3G, 3R... Phosphor that is insensitive or has low sensitivity to the light emitted by the optical index phosphor. ward ward
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Claims (1)

[Claims] In a bulb in which three primary color emitting phosphors and a light index phosphor are repeatedly formed in stripes in a predetermined order on the inner surface of the bulb, two color light emitting phosphor stripes adjacent to the light index phosphor stripe are each formed as a light index. A beam index cathode ray tube characterized by being constructed of a phosphor that is insensitive or has low sensitivity to the light emitted by the phosphor.