Method for improving uniformity of kinescope white field

Abstract

The invention discloses a method for improving the uniformity of a white point of a kinescope; designs are carried out on the internal and the external curved surfaces of a screen; the falling off amount of the point of the effective surface corner of the external curved surface of the kinescope screen furthest to the center of the screen relative to the center of the external surface of the screen is h; in the section of the kinescope shaft of a colorful kinescope, the inside curve of the screen surface is formed by the crossing of the plane of the kinescope shaft and the internal curved surface of the screen; the inside curve is arranged between the surrounding sides which play the role of displaying the effective ranges in the center of a screen surface P0; the screen surface is at least provided with one section with inflexion points; the tangent of the internal curve and the kinescope shaft are orthogonal to form the maximum value of a plane angle of Alpha between the center of the screen surface P0 and the inflexion points; the minimum value of the include angle formed by the tangent of the internal curve and the plane vertical to the kinescope shaft is Beta between the inflexion points and the surrounding sides which display the effective ranges; the values should meet that Beta / Alpha is equal to or more than 0.6 and less than 1.0. The method can improve the uniformity of the white point and increase the brightness ratio.

Description

technical field [0001] The invention belongs to the technical field of color picture tubes, and in particular relates to a method for improving the uniformity of the white field of the picture tube. Background technique [0002] Generally, a color picture tube has a device consisting of a substantially rectangular screen and a cone integrally connected with the screen. The color picture tube is on the inner side of the screen, and a rectangular fluorescent film is formed by blue, green and red fluorescent strips or fluorescent spots. Corresponding to the fluorescent film, a substantially rectangular shadow mask with openings (having many small holes) is mounted on the inner wall of the screen within a rectangular range corresponding to the display effective range of the rectangular screen. In addition, electron guns emitting colored electron beams R, G, and B are installed inside the neck of the cone. The electron beams R, G, and B emitted by the electron gun are deflected...

AI Technical Summary

Problems solved by technology

Because the degree of curvature of the curved surface in the screen will affect the fluidity of the phosphor paste, the width distribution of the phosphor stripes cannot be "smoothly" transitioned, and the film quality of the phosphor surface is not good.

In particular, the curvature of the inner curved surface of the AK tube is larger than that of the invar material. At the same time, the curved surface outside the screen is too flat. If a curved surface with R=100000mm is used, the thickness of the glass at the corner will be too thick. When the phosphor is coated, the temperature distribution on the inner surface of the screen will be uneven. Moreover, glass with bottom transmittance is used in the current market, resulting in poor white field distribution, low brightness at the corners, and a brightness ratio of less than 45%.

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