| 摘要 |
PROBLEM TO BE SOLVED: To provide a monitor camera apparatus which can focus in the dark, even if focus setting made when it is bright. SOLUTION: A microcomputer 14 gradually increases the shutter speed of an electronic shutter at setting the focus. This lowers the output signal level of an imaging device 12, and an orifice control circuit 15 detects the decreased speed to reduce the diaphragm value of an orifice 11c. After the orifice 11c reaches its fully open position, the microcomputer further increases the shutter speed to further lower the level of the input signal to an AGC circuit 13a. When the input signal level to the AGC circuit 13a is lowered below specified, the AGC circuit 13a starts amplifying the signal. This start time is taken as the focus decision timing, based on the image signals taken. COPYRIGHT: (C)2003,JPO |
