Shadow mask

Abstract

In a shadow mask 21, a large number of slots 23 are made in a mask body 22 in the horizontal direction X and in the vertical direction Y. Each slot 23 has a roughly rectangular backside opening 33, a roughly rectangular front-side opening 32, and a through-hole 31 that connects these two openings 33, 32. Of the multiple slots 23 made in the mask body 22, the slots 23 situated at least in those areas of the mask body 22 that are surrounded by a horizontal axis 24 and two diagonal axes 26, 27 that pass through the center point 28 of the mask body 22 have such front-side openings 32 that a pair of the upper and lower short sides 32c, 32d of the rectangular outline of the front-side opening 32 of each slot 23 are inclined, relative to the horizontal axis 24, along the radiate line 61 radiating from the center point 28 of the mask body 22 toward the slot 23. The angle [beta] of inclination of the short sides 32c, 32d is preferably in the range of +- 10 DEG , where +- is the angle [alpha] between the radiate line 61 radiating from the center point 28 of the mask body toward the slot 23 and the horizontal axis 24.

Description

technical field [0001] The present invention relates to a shadow mask for forming a substantially rectangular electron beam spot on a fluorescent surface of a color cathode ray tube. Background technique [0002] Such as Figure 8 As shown, the shadow mask 1 is used so as to be placed opposite to the fluorescent surface 102 of the color cathode ray tube 101 . In the color cathode ray tube 101, the electron beam 105 emitted from the electron gun 103 and deflected by the magnetic field of the deflection yoke 104 passes through the shadow mask 1 and lands on a predetermined position on the fluorescent surface 102 accurately. [0003] Here, the shadow mask 1 will be described in detail. Figure 4 It is a schematic plan view for explaining the positional relationship of the slits formed in various parts of the shadow mask 1 . Such as Figure 4 As shown, the shadow mask 1 has a substantially rectangular shadow mask main body 1a, and on the shadow mask main body 1a, there are su...

AI Technical Summary

Problems solved by technology

This phenomenon will cause the following problems: the electron beam 7b passing through the slot 2d is partially missing, resulting in a decrease in luminance, and it is impossible to make a light spot of a desired size and shape fall on the fluorescent surface of the cathode ray tube.

Images