| 摘要 |
PROBLEM TO BE SOLVED: To prevent a display (PDP), etc.), from being burnt by displaying pseudo-white noise on a screen while a video image signal input is broken off by channel change, etc. SOLUTION: Pattern data of necessary number of kinds lighting with a high intensity are stored in a noise pattern storage part 1 with each cell position of PDP 11 sequentially shifted by one cell and are read at intervals of 1/60 second, etc. The data are converted into analog data by D/A converter 2, and a pseudowhite noise signal generation part 3 generates a pseudo-white noise signal having a synchronous signal. A video image signal from terminal 4 is inputted to A/D conversion part 9 via switch 8, converted into digital signal, subjected to gamma correction and synchronizing processing, and impressed on PDP to display a video image. The video image signal from terminal 4 is detected by a video image signal detecting part 5, and when a state of no video image signal continues for a predetermined time, a switch is changed over to the side b by a signal from a clock part 6 through a control part 7 and the signal from the pseudo-white noise signal generation part is displayed on PDP. |
