| 摘要 |
PURPOSE:To enable highly accurate measurement of a distance by delaying a distance measuring sequence by more than a fixed time after a gain change of a gain control amplifier to operate the gain control amplifier in the optimum state. CONSTITUTION:Distance measuring light which is projected from 2 projection section 2 to be reflected on an object S1 is received with a photodetecting section 7. A distance-distance signal is calculated with a microcomputer 14 from an output of a gain control amplifier of an automatically focusing IC for amplifying the resulting output. At this point the level of an output signal of the gain control amplifier is monitored and adjusted when it is outside a specified range. In the changing of the gain, a time is set as required for the stabilization of the gain of the gain control amplifier and after the period set passes, the lighting of a projection section 2 is allowed so that an output of the gain control amplifier is sampled in stable state. Thus, higher distance accuracy is achieved without picking up an improper measuring data with unstable gain. |
