JPH0623653B

PURPOSE:To enable the obtaining of higher resolutions on the long range side regardless of a larger ratio of long and short limit ranges, by a method wherein light from objects on the long and short range sides is made incident upon different light receiving areas as light spots and photo currents are outputted from signal leading-out electrodes of the respective light receiving areas. CONSTITUTION:A light receiving section [comprising (n) light receiving areas 521-522] is formed by diffusing P-type impurities evenly on the surface of a high resistance silicon substrate 51 while an n type conductive layer 53 having n-type impurities diffused at a high density on the back thereof 51. When light from an object 3 to be measured is made incident upon the light receiving section of the apparatus 5 as light spot, the position of the light spot is detected based on photocurrent drawn from both ends thereof. Here, in the areas 521-52n, one pair each of signal leading-out electrodes 55a1-55an and 55b1-55bn is arranged in a row with one electrode thereof adjacent to the other and the interval of the respective signal leading-out electrodes is multiplied equally in sequence.