| 摘要 |
PURPOSE:To reduce the nonuniformity of characteristics in the central part of an element and the peripheral part thereof and to improve the precision, by a method wherein a reflected light corresponding to a distance measurement region is sensed by a discrete light position detecting element. CONSTITUTION:The upper-end region (a) of PSD 166 and the lower-end regions (b) and (c) of PSDs 167 and 168 are non-light-sensing regions respectively. Even when light spots 30Sa and 30Sb on the PSDs 167 and 168 formed by two peripheral part reflected light fluxes 30Ra and 30Rb fall on the PSD 166, in such a light-sensing device 100 as mentioned above, the division ratio of a photocurrent of the PSD 166 due to the light spots is equal to the division ratio between the PSDs 167 and 168, and distance measurement data determined from a coupled of photocurrents I1 and I2 are accurate. Since the regions (a)-(c) on the PSDs which are not used for distance measurement are screened from a light, an effect of a disturbance light is little produced. |
