| 摘要 |
A photosensitive element having first and second sensitive regions arranged to receive a light spot in such a way that as the light spot lies astride the boundary therebetween, the ratio of the areas of the two parts of the spot light which are received by the first and second sensitive regions, respectively, varies depending on the received position of the light spot, whereby the received position of the light spot is detected from the variation of the ratio of the outputs of the first and second sensitive regions, wherein an error of variation of the ratio of the outputs of the first and second sensitive regions for the received position of the light spot, which takes place when the diameter of the received spot light is so large as to overrun the first and second sensitive regions, is corrected by providing a supplementary sensitive region surrounding the first or second sensitive region.
|
