CRT having color filter with a special green filter

Abstract

A color picture tube is disclosed, that comprises an outer sheath having a electron gun, the outer sheath being airtightly sealed, a face plate having light transmissivity and disposed on the front surface of the outer sheath, and a large number of red, blue, and green pixels regularly arranged inside the face plate, wherein the pixels have a fluorescent substance layer and a color filter, the fluorescent substance layer being lit by a radiation of an electron beam, the color filter being disposed between the fluorescent substance layer and the face palate, and wherein green pixels have a chromaticity that is plotted in the fourth quadrant of a coordinate system of a (L*a*b*) color system where a* is the horizontal axis and *b is the vertical axis when light of a standard light source C is reflected on the outside of the face plate.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a color picture tube, in particular, to a color picture tube for displaying data with high luminance and high contrast.2. Description of the Related ArtA conventional color picture tube has a face plate that has light transmissivity and an effective display surface for displaying a picture. A fluorescent substance layer is deposited on the inner surface of the effective display surface of the face plate.A funnel that is a hollow cone with a tube extending from the smaller rear end is disposed on the rear end of the face plate. The front end of the funnel is connected to the rear end of the face plate. Thus, a sealed vessel as a sheath of the color picture tube is formed.An electron gun is disposed inside the rear end of the funnel. The electron gun scans and radiates an electron beam to the fluorescent substance layer corresponding to a display picture.The path of the electron beam emitted from the ...

AI Technical Summary

Benefits of technology

An object of the present invention is to provide a color picture tube for satisfactorily improving the luminance of the effective display screen, the contrast characteristics, and the coloring characteristics of each color including green of the display picture so as to accomplish a high quality picture display.

Problems solved by technology

However, with the conventional technologies, it is difficult to improve both the brightness and contrast.

However, when the energy of the electron beam is increased, the current consumption of the color picture tube increases.

Thus, the power consumption of the color display apparatus increases.

Practically, it is very difficult to equalize the wall thickness of the entire face plate of the flat type color picture tube.

However, in this case, the power consumption increases.

Thus, the total power consumption of the color picture tube remarkably increases.

However, with this method, a good result cannot be obtained.

Nevertheless, the filter performance of the color filter layer composed of such an inorganic pigment is not satisfactory.

In other words, with conventional pigments for green cells, satisfactory selective absorbing characteristics cannot be accomplished (namely, good coloring characteristics cannot be accomplished).

When a picture is displayed on the color picture tube with such green cells, the green cannot be correctly displayed.

Thus, the body color cannot be properly displayed.

Therefore, although the white is created mixing the three primary colors, it is difficult to display the white with high purity.

However, in this case, even if the coloring characteristics are satisfactory, since the light transmissivity decreases and thereby the contrast characteristics (BCP) deteriorates.

As described above, with the conventional technologies, it is very difficult to satisfactorily improve the luminance of the effective display screen, the contrast characteristics, and the coloring characteristics of each color including green.

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