| 摘要 |
PURPOSE:To make it possible to obtain fine output by driving a shift register circuit synchronously with the drive of an image sensor, controlling electronic attenuator with D/A-converted voltage as to the contents and obtaining even video output. CONSTITUTION:Comparator 11 compares a part of video output 12 with a signal of output standard setting circuit 10 and a signal for indicating whether output 12 is larger, smaller or equal than/to the set voltage of circuit 10 is entered into control circuit 9. At the input of the signal, circuit 9 controls circuit 7 so as to be up-mode, down-mode or count stop. The contents of shift register circuit 6 which has the same number of addresses as the number of photodetectors of image sensor 2 are set on circuit 7 and simultaneously inputted into D/A converting circuit 8. Output 12 of electronic attenuator circuit 5 is controlled by using the voltage as control voltage. Even when lighting is uneven or photodetectors are positioned unevenly, excellent output can be obtained by correcting the unevenness before measurement. |
