| 摘要 |
PROBLEM TO BE SOLVED: To prevent the collapse of a high luminance part by controlling the amplitude of an input video signal to be within the dynamic range of an A/D conversion section. SOLUTION: Video signals of R, G and B from terminals 1a to 1c are amplified by amplifier sections 4a to 4c and impressed to voltage control amplifier sections 9a to 9c. A reference pulse generation section 5 generates a reference pulse having a required amplitude during blanking of the video signals, this reference pulse is synthesized into the video signal G or the like from the amplifier section 4b by a reference pulse synthesizing section 6, a peak is detected by a peak detecting section 7, this peak value is held by a peak holding circuit 8, the amplifying degrees of the voltage control amplifier sections 9a to 9c are controlled based on this peak value and exceeding of the dynamic range of A/D conversion sections 10a to 10c is prevented. Signals from the A/D conversion sections are processed by a signal processing panel driving section 11 and, by driving a PDP 12, the videos are displayed. |
