A CIRCUIT FOR PREVENTING CRT DAMAGE AND A METHOD FOR PREVENTING CRT DAMAGE IN PROJECTION TV

摘要

The present invention relates to a projection TV (TV) cathode ray tube damage prevention circuit for preventing a cathode ray tube that lowers a brightness value of a point from being detected when a same pattern is output from a specific portion of a screen of a projection TV for a long time, And a cathode ray tube damage prevention method. Conventionally, a cathode ray tube protection circuit of a projection TV can prevent damage to a cathode ray tube only when the entire screen is a still image. However, in reality, the entire screen is rarely a still image, Since the pattern continues to be output, the remaining portion is often a moving image, and thus the CRT can not be protected.;In other words, since the projection TV is large, it is often used for various displays such as an amusement machine and a computer. In such a case, the cathode ray tube is damaged because a certain portion is fixed to the desktop.;SUMMARY OF THE INVENTION The present invention has been made in order to solve such a conventional problem by detecting points of a specific portion when a specific portion of a screen is output in the same pattern over a long period of time and lowering the luminance value of the detected points, To the projection TV.