| 摘要 |
PURPOSE:To perform excellent automatic focusing operation even when a subject is red, blue, etc., by interposing an infrared-ray cutting filter in front of a focus sensor when the level ratio of blue and red of image light from the subject decreases below a specific value. CONSTITUTION:An image pickup signal from an image pickup tube 1 is supplied to a signal processing circuit 5 and primary color signals B and R of blue and red obtained from the signal processing circuit 5 are supplied to a decision circuit 12. This decision circuit 12 decides on the level ration B/R of the primary color signals B and R of blue and red and outputs a control signal when the level ratio B/R is smaller than the specific value. A position changing means 13 is controlled with the control signal Sc to interpose the infrared-ray cutting filter 11 in front of the focus sensor 7. |
