| 摘要 |
PROBLEM TO BE SOLVED: To improve distance measuring accuracy by providing an arithmetic circuit or the like for calculating a distance to a subject from results for reading an output of an A/D-conversion circuit over a predetermined number of times. SOLUTION: When a light projection signal is output from a CPU 11 (arithmetic circuit), light from a light projection circuit 20 passes through a projection lens 1, it is reflected on a subject, and a part of it passes through a light receiving lens 2 and it enters light receiving circuits (current-voltage conversion circuits 30, 40). Amplification circuits 50, 60 amplify output signals from the current-voltage conversion circuits 30, 40, and an integration circuit 70 integrates an output signal from the amplification circuit 60. An A/D-conversion circuit 15 converts output voltage from the integration circuit 70 and outputs it to the CPU 11. The CPU 11 calculates a distance to the subject from results for reading the output from the A/D-conversion circuit 15 over a predetermined number of times. A motor 12 is controlled by the CPU 11 and drives a recording lens 13 to a focused position. A release switch 14 is connected to the CPU 11. |
