| 摘要 |
PURPOSE:To obtain a sharp and excellent color picture without any change in color tone regardless of shutter speed by replacing a black reference level (no signal period) obtained from a CCD image pickup element at image pickup into an optical black reference level at shielding of light stored in advance. CONSTITUTION:The CCD image pickup element at the back of an image pickup lens 1 outputs a frequency multiplex signal including a luminance/color signal to a DC recovery circuit 6. Optical reference level information corresponding to an output signal of the CCD image pickup element 4 when an incident light shielded is stored in a ROM 12 as to all cases when the shutter speed is changed stepwise. The ROM 12 outputs optical black reference level information in response to the shutter speed when a control signal is given from a shutter speed setting circuit 8, and an optical black reference level switching circuit 15 replaces a referencelevel obtained from the element 4 via the circuit 6 into a black reference level from a DA converter 13 and outputs it as a signal having an accurate optical black reference level to a signal processing circuit 16. This signal becomes a frequency modulation signal, fed to a magnetic head 19 and recorded on a magnetic disc 20. |
