| 摘要 |
PURPOSE:To keep the accuracy of A/D conversion data and to secure the picture quality of a print picture by consisting an AGC circuit which keeps the output level of an A/D converter constant and executing a correction to the A/D conversion data to print in the ratio obtained by comparing the AGC detection level for the duration of a horizontal synchronizing signal with a prescription input level. CONSTITUTION:When a system controller 18 outputs a freezing command and a freezing mode is obtained, a switch 12 is connected to the contact point R of a synchronizing signal separation circuit 10 side and a timing control circuit 17 writes one picture of data synchronizing to an input signal in a picture memory 13. At the time of printing, the system controller 18 outputs a printing command and the switch 12 switches to connect to the contact point P of a synchronizing signal generation circuit 11 side. According to a synchronizing signal generated by a reference clock the timing control circuit 17 reads the data from the picture memory 13. After the data is D/A converted it is demodulated to R, G and B signals in a decoder circuit 19. A switch 20 converts them according to the output of the system controller 18, for example, into the order such as R, G and B to execute printing. |
