| 摘要 |
PURPOSE:To perform automatic focus adjusting operation stably with high precision by performing control on the basis of a reference signal which follows up the sum of the quantities of incident light of two photodetection parts and a signal corresponding to the difference in the quantity of incident light. CONSTITUTION:A light beam projected by a light projecting means 11 is reflected by an object 10 and enters two photodetection parts of a photodetecting means 12 and the outputs of the photodetection parts 12a and 12b are led to a reference signal generating means 13 and an adjusting circuit 14. The reference signal generating means 13 generates the reference signal which follows up the sum of both photodetection outputs and the adjusting circuit 14 generates an automatic focus adjustment signal from the reference signal and a signal corresponding to the difference between both photodetection part outputs. This automatic focus adjustment signal is used to feed a lens driving motor which moves a photographic lens to an in-focus position etc. |
