| 摘要 |
PURPOSE:To prevent a range from being mismeasured owing to the start characteristics of a light emitting element by providing a control means which makes the output signal of a light receiving element ineffective when the number of times of projection of distance measuring light is less than a constant value. CONSTITUTION:When LEDs 3a - 3c are actuated, their light emission outputs are smaller than those in their stationary light emission states, so distance measurement data obtained by 1st and 2nd light emitting operations are processed as ineffective data and distance measurement data obtained by 3rd and succeeding light emitting operations are utilized to determine a gain. Namely, when the number of times of pulse light emission by a projecting element 2 is less than the constant value, the output signal of the light receiving element 7 is ignored. Consequently, accurate distance measuring operation can be performed without being affected by variation in the quantity of light due to the light emission characteristics at the time of actuating the projecting element 2. |
