| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-cost and miniaturized range finder capable of performing high-accuracy AF(automatic focusing) by disposing electrically switchable diffraction optical elements in a light projecting path or in a light receiving path to perform range finding relative to a plurality of areas in a photographing screen. SOLUTION: ESHOEs 13, 14 as diffraction optical elements equipped with the optical characteristic of a phase-type volume hologram are disposed in the light projecting path of a light projecting part including a light emitting diode(LED) 10 and a light projecting lens 12. An ESHOE driving circuit 16 is driven by a microcomputer 20 to on-off control the diffraction of each of the ESHOEs 13, 14. Reflection light from a subject comes into light receiving surfaces of a line sensor 19 through light receiving lenses 17, 18, and an output to which a stationary light removal function is applied is supplied from the line sensor 19 to the microcomputer 20. The microcomputer 20 performs arithmetic processing control for range finding based on an output corresponding to the accumulating action of the line sensor 19. |
