| 摘要 |
PROBLEM TO BE SOLVED: To shorten the range finding time of a range finder even when the finder repeats range finding operations by providing a control means which sets the initial value used at the time of lowering the light receiving quantity in steps at the second and after second range finding time based on an appropriate value found at preceding range finding time when the range finder continuously measures the distance to an object to be measured. SOLUTION: A range finder is provided with a light receiving quantity changing means which finds an appropriate value by lowering the light receiving quantity of a light receiving sensor in steps from a prescribed initial value when the sensor is saturated by excessively powerful reflected light from an object to be measured. At the first range finding time, a set value (appropriate value) is found by setting the initial value of the exposing time of an electronic shutter at, for example, 100% and successively subtracting a prescribed amount from the initial value, but, at the second and after second range finding time, the initial value is set at a value which is larger than that set at the first range finding time by one step and the set value is found by successively subtracting the prescribed amount from the initial value. Consequently, the number of computing time until the set value is reached is shortened. Therefore, the range finding time of the range finder is shortened and releasing time lags can be reduced. |
