Cathode-ray tube

Abstract

A Cathode Ray Tube (hereinafter, CRT), includes a mask assembly which is composed of a main frame for supporting the shadow mask and a sub frame for supporting the main frame. When the minimum distance between the flat surface extended from the upper surface of the main frame and the flat surface extended from the lower surface of the sub frame is Lb, the height of the sub frame is Ls and the minimum distance between the flat surface extended from the upper surface of the main frame and the flat surface extended from the lower surface of the sub frame, in case the mask is attached to the mask assembly, is La, the following equation, 0.40<=Ls / Lb<=0.55 or 0.45<=(Ls-Lm) / Lb<=0.59 is satisfied and after compression, the following equation, 0.08<=(La-Lb) / (Lb-Lm)<=0.17 is satisfied. Therefore, the creep phenomenon, causing tension degradation and wrinkles at the corner portion of the shadow mask after the heat processing, can be prevented and the howling phenomenon, which can cause serious degradation of quality of screens by vibration of the CRT, can be prevented, considering the instrumental formality with a panel at the same time.

Description

field of invention [0001] The present invention relates to a cathode ray tube (hereinafter also written as CRT), and in particular to a frame of a color cathode ray tube capable of preventing the creep phenomenon caused by the tension drop and heat treatment steps and the microphonic phenomenon of the cathode ray tube . Background technique [0002] Typically, a color CRT with a flat screen, such as figure 1 As shown, it is composed of a front glass called a screen 10 and a rear glass called a funnel 20, and they are bonded to each other, and the inside is a high vacuum after sealing. [0003] Inside the CRT, a phosphor layer 40 is formed on the inner surface of the panel 10 as a predetermined light emitting material. The electron gun 130 is used for electron beam scanning, and the electron beam is emitted to the fluorescent surface 40 . The shadow mask 70 is used to sort colors so that the electron beams 60 generated in the electron gun 130 are irradiated to a predetermi...

AI Technical Summary

Problems solved by technology

[0038] Therefore, due to the above-mentioned problems, the relative positions of the fluorescent surface 40 within the shadow mask 70 and the screen 10 are changed, so that problems such as color impurity may occur.

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