Automatic exposure device of endoscope photographic system

Abstract

Abstract PURPOSE:To perform high-precision automatic exposure by calculating an exposure value on the bais of a photographic exposure value and the amount of lighting to a subject before photographing. CONSTITUTION:Flash lighting for a prescribed time is controlled through a CPU55 and the quanitity of flash light based upon photometric information is stored in an RAM57 through a photodetector 32 and an A/D converter 58. At the same time, an aperture dynamic range, etc., for a light source is calculated. Then when the attachement of a camera is detected by a serial interface 54 is detected, the amount of lighting based upon the information of the photodetector 32 is calculated and written in the RAM57. Similarly, reflected light corresponding to the amount of photographic light based upon the photometric information by the photodetector of the camera from an operational amplifier 67 is calculated and written in the RAM57 to calculate an exposure value before photographing through the CPU55 according to set ASA information, etc. During the photograhing, the CPU55 controls flash lighting time, aperture, etc., and when the integral value of exposure corresponding to the information of the camera photodetector coincide with the exposure value before the photographing, a shutter is closed to perform high-precision automatic exposure without any influence upon variation in light source characteristics, etc.

Inventors

• 👤 Seiichi Hosoda
• 👤 細田　誠一

Bibliographic Details