| 摘要 |
PURPOSE:To greatly reduce the effect due to vibrations of an object to be measured to the error of measurement, by calculating the output signal obtained through a simultaneous and backward scan of a solid-state image pickup element and then delivering the mean value in the form of a displacement signal. CONSTITUTION:Two image sensors 21 and 22 are provided, and the sensor 22 receives the beams branched through a half mirror 9. These two sensors are scanned simultaneously in the same speed and in the opposite directions to each other by a clock oscilltor 31 and a clock driver 32. In such constitution, the light given from a light source is irradiated to a moving object A to be measured, and the output signals received at a time by the sensors 21 and 22 are amplified by amplifiers 51 and 52. The mean value of both signals is calculated through an arithmetic circuit 8 to be turned into an output signal. In such way, the error of measurement caused by the vibrations of the object A can be greatly reduced compared with the conventional circuit. |
