| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic luminance adjustment system capable of reducing a circuit scale and highly precisely adjusting luminance in short time. SOLUTION: An automatic luminance adjustment system automatically adjusts a DC level of a video signal supplied to a drive transistor 18R driving a cathode electrode of a cathode ray tube 2. The system includes: a DC adjustment circuit 13R adjusting the DC level of the video signal based on DC level adjustment data DC(R); an OSD signal generation circuit 19 generating an R primary color signal corresponding to a black signal for DC level adjustment of the video signal during a video signal period; a comparator 22 comparing a feedback voltage VF(R) corresponding to current flowing in the drive transistor 18R and a DC level reference voltage VREG(R) based on the R primary color signal corresponding to the black signal whose DC level is adjusted by the DC adjustment circuit 13R when luminance is adjusted; and a DC level adjustment data generation circuit 23 generating the DC level adjustment data DC(R) in accordance with a comparison result of the comparator 22. COPYRIGHT: (C)2012,JPO&INPIT |
