| 摘要 |
PROBLEM TO BE SOLVED: To provide a device capable of easily correcting the brightness irregularities of R, G and B on a projection screen in a projection image display device without being affected by power fluctuation, temperature change and noise. SOLUTION: The amplitude of respective video signals and a DC level in the respective areas divided in a grid shape of the projection screen are corrected by a digital signal processing. Corrected digital video signals composed by computing correction data (amplitude correction data and DC level correction data) sent from a brightness irregularity correction memory 2 to the digital video signals of R, G and B are outputted from a brightness irregularity correction arithmetic memory 5 to a D/A conversion circuit 6 and converted to analog video signals. A gamma correction processing, a blanking processing and an OSD processing are simultaneously performed in the same circuit together with the brightness irregularity correction. |
