| 摘要 |
PURPOSE:To quickly output the distance measuring result in close response to the given situation and decrease the time lag in releasing by allowing infrared photo-emission elements at different distance measuring points to emit light in a short time one after another before the normal operations for distance measuring takes place, and judging in a short time whether any object to be photographed exists. CONSTITUTION:Pre-measuring motion for distance is commenced with turning-on of a switch 11 interlocked with depression of a release button for its first stroke, and the central IRED 6 is lighted up for several milliseconds. The output of a distance measuring circuit 13 is judged by a level judging circuit 14, and a flag is established which puts off the central IRED 6 at the next regularly specified motion for distance measuring if the output of the circuit 13 is smaller than the reference value. In the same manner, lighting-up of the left and right IREDs 5, 7 is conducted associated with the distance measuring operations. After this pre-measuring process for distance, the regular operations are commenced, and examination is made whether the flag to put off the IREDs is established, and only that (those) of IREDs which is (are) out of flag establishment is (are) allowed to light up for regular distance measurement. If no object photographed exists at any point, the distance measuring motions are omitted for this point, which should save the time for sparing to the distance measuring motions. |
