CRT(CATHODE-RAY TUBE) DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To enhance the contrast of display and also to make video noise at a low luminance part inconspicuous in a CRT display device in which a CRT (MM(multi-media) tube) having luminance higher than that of the conventional CRT is mounted.;SOLUTION: In this display device, a video signal modulating circuit 10 converts a video signal (first video signal) into a second video signal in which the signal level of a low gradation area is suppressed lower than that of the first video signal. As a result, since a cathode bias voltage source 7 generates the driving voltage of the low gradation area based on the second video signal, the driving voltage of the low gradation area is suppressed low and the luminance of the low gradation area in a CRT 1 become low. Thus, the video noise of the low luminance part becomes inconspicuous and, moreover, a contrast value becomes large and display quality is enhanced.;COPYRIGHT: (C)2002,JPO