| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need for determining a gain of a distance-measuring circuit and measure a distance at high speed highly accurately. SOLUTION: A first and a second capacitors 61, 62 store integrated values after amplified of a pair of outputs from a photodetecting element 31 which detects a reflecting light as a light reflected at an object to be photographed of a measuring light projected through the projection of a light-projecting circuit 20 by a predetermined number of times. A sum voltage of the first and second capacitors 61, 62 and a voltage of the capacitor 61 are simultaneously input to an A/D converter 14. The A/D converter 14 generates an output corresponding to a ratio of the sum voltage and the voltage. Since the apparatus is provided with the A/D converter 14 as well as a control circuit 11 for driving a photographing lens based on the output of the A/D converter 14, an operation for determining a gain of an amplifying circuit 40 is eliminated and a circuit scale is reduced. |
