Projection type rangefinding device for camera

Abstract

Abstract PURPOSE:To rapidly attain the measurement of distance by irradiating an object with flash light once by a light projection part, deciding the obtained level of a photoelectric output and starting integration for a certain time by an integrator after switching the gain of an amplifier or the intensity of light from the projection part. CONSTITUTION:An LED 11 is flashed once just before starting the integration for an actual range finding action. And when the photoelectric output at that time is above a specified level, the gain of the differential amplifier 38 is switched to a low one and thereafter the integration for a certain time is started. Then, it is evaded that the output of signal from the differential amplifier 38 is saturated or the capacitor 53 of the integration circuit 48 is overcharged, so that a rangefinding signal without an error can be obtained. Now, it is good to adjust the level of the output of the signal before integration by altering the luminance of the light projected to the object. Thus, the precise and rapid range-finding action can be executed.

Inventors

• 👤 Minoru Ishiguro
• 👤 Yoshinobu Takahashi

Bibliographic Details