| 摘要 |
PURPOSE:To raise the operation accuracy of a focused state even if a pitch of a sampling point is comparatively rough by providing a means for calculating a correlation quantity given by a prescribed expression from a photoelectric converting signal of a time series from plural photoelectric converting means. CONSTITUTION:Photoelectric converting element arrays 7, 8 output photoelectric converting signals a(i), b(i) by a time series, and b(i) is converted to a signal b(i+1) by a shift register 9. A comparator 10 compares the signal a(i) and b(i+1), turns on a switch 11 in case of a(i)<b(i+1), and turns on a switch 12 through an invertor 13 in case of the contrary. A comparator 14 turns on a switch 16 through an invertor 15 in case of a(i)<b(i), and turns on a switch 17 in case of the contrary. A correlation quantity signal V=SIGMAmin[a(i), b(i+1)]- SIGMAmin [a(i), b(i)] is outputted from a subtracter 20 through integrators 18, 22, and an operation of a focused state is executed with high accuracy. |
