| 摘要 |
PURPOSE:To improve start characteristics after power-on operation apparently by setting an incidence time to zero or a small value right after a shutter means which allows an optical image to be incident to an image pickup means periodically for a specific time is started. CONSTITUTION:When a power source circuit 105 is turned on, respective circuits are powered on and a scan on a CCD18 is started by the output of a clock generator 107. Further, a motor 17 rotates to obtain one pulse on every turn, and a gate 103 is opened to supply a time constant circuit 102 with a voltage corresponding to the predetermined angular aperture. This time constant circuit 102 controls to the angular aperture of the shutter gradually to a specific value. Therefore, the shutter rotation starts at the minimum angular aperture, i.e. the minimum exposure time value and the angular aperture is held smaller than a set value until the rotation of the motor 17 increases in speed sufficiently. |
