| 摘要 |
PURPOSE: To realize highly accurate focal point detection by varying the target output value from an image sensor depending on the amplification factor and performing the storage control thereby obtaining an appropriate image output even if the saturation level of the image sensor changes. CONSTITUTION: A storage time calculating section 5 calculates an appropriate storage time based on an amplified image output from an amplifier 4, a target output value (AGC target value) from an image sensor 3 selected depending on the amplification factor, and amplifier gain information from a gain switching section 6 and then delivers the storage time to an image sensor drive control section 7. The control section 7 controls the charges being stored in the sensor 3 based on the storage time thus calculated 5. An operating section 8 calculates the defocus amount of an objective lens 1 based on an amplified image output from the amplifier 4 and controls a motor 10 through a drive control section 9 to focus the lens 1. Since the target output from he sensor is selected depending on the amplification factor, an appropriate image output can be obtained even if the saturation level of the sensor 3 varies. |
