| 摘要 |
PURPOSE:To set focusing of a lens with good reproducibility, by setting the lens at a focusing position, where the output signal of a one-dimensional image sensor element becomes a peak or the differential of the output signal becomes the maximum. CONSTITUTION:A one-dimensional image sensor element 12 has a light receiving part 3. The outputting is performed in time series. The maximum value of the output of the light receiving part 3 is detected by a peak holding circuit 16. The operation of the image sensor element 12 is performed without relation to the driving of a lens, and the signal is always outputted. Then, e.g., the change in peak value of the held output signal of a differential circuit 17 is detected. For this purpose, a part of the output of the peak holding circuit 16 is guided to a delay circuit 15. The signal change before and after the driving of the lens is detected by a comparator circuit 14, amplified, and transmitted to a lens driving device 13. Thus the lens is set. In this way, the setting of the focusing of the lens can be performed with good reproducibility. |
