| 摘要 |
PURPOSE:To secure the proper exposure of even a subject which has extremely large or small reflectivity by stopping light emission when the integral value of reflected light form a subject reaches a prescribed value and thus holding the integral value of the reflected light constant. CONSTITUTION:After the standard time t1 when the integral value of reflected light form a subject with standard reflectivity R0 reaches its adequate value, if the integral value is between an upper limit level set higher than the adequate value and a lower limit level set lower than the adequate value, light emission is stopped through a light emission stop signal generating circuit 63, light quantity control circuit 32, etc., to obtain the integral value of reflected light proportional to the reflectivity R of the subject. Consequently, when the integral value reaches the upper limit level within the standard light emission time t1 or reaches the lower limit level after t1, the light emission is stopped to suppress the integral value of reflected value below a specific level. Thus, the proper exposure of even a subject having extremely high or low reflectivity is secured. |
