Video circuit for driving crt

Abstract

Abstract PURPOSE:To prevent the generation of a luminance unevenness on a displaying surface when a raster is displayed by mixing a horizontal synchronizing signal so as to make coincident the level of a horizontal synchronizing signal period in a composite video signal to a blanking level. CONSTITUTION:The polarity and amplitude of a horizontal synchronizing signal Hs are suitably adjusted and impressed to the base of a transistor 5 so that a horizontal synchronizing signal to appear at the positive side from a blanking level outputted to a CRT cathode can be cancelled and the level can go to be flat in the blanking level. Namely, when the signal level in the horizontal synchronizing period of a horizontal synchronizing signal Hs inputted to the base of the transistor 5 is adjusted by a variable resistance 15, the level goes to be flat in the blanking level. Thus, the level difference between the blanking level in a composite video signal and the peak level of a horizontal synchronizing signal is eliminated and the luminance unevenness is cancelled on the display.

Inventors

• 👤 Takashi Nakajima
• 👤 Tadashi Kubota

Bibliographic Details