| 摘要 |
This invention provides a circuit for generating a center point of a view finder comprising; a horizontal display-signal generation part 10 for generating the horizontal display-signal by adjusting the time constant of the monostable multivibrator IC1-IC4, a vertical display-signal generation part 20 for generating the vertical display-signal using 8-bit counter IC5 in which the horizontal drive-pulse is reset by the vertical drive-pulse, a center point display-signal composition part 30 for generating the center point display-signal by composition of the output of the horizontal and vertical display-signal generation parts 10 and 20, and a video signal composition part 40 for composition of the output of the center point display-signal composition part and the video signal and providing the composed output signal. Adjusting more accurately the center point of the image by a circuit rather than by a mechanism and removing the recording error may be attained, moreover, by controlling the linearity and having an utility in use may be attained according to the circuit of the present invention. |
