JPS6422173A - Image input device - Google Patents

Abstract

PURPOSE:To automatically optimize an input light quantity by detecting the peak value of the output signal of a CCD camera, comparing it with a reference value, and controlling a diaphragm with a motor driven and controlled by the comparing output. CONSTITUTION:Light from a light source 20 is made incident through an infrared absorption filter 28 and a light guiding member 30 on many optical fibers 22 consisting of a fiber bundle 24. The optical fiber 22 is connected to a lengthy housing 32, and the light from the optical fiber 22 is radiated on an original S through a condensing lens 25. A reflected light L2 is made incident through a condensing lens 36 on a CCD camera 14. An output signal SC photoelectrically converted by the camera 14 detects the peak value at a peak holding circuit 52, and is compared 54 with a reference value VR. According to the output of a comparator 54, the output of a motor driving circuit 56 is fed back to a motor 38, and a diaphragm 50 is rotated regularly and in reverse. The output signal SC is A/D-converted and stored in an image memory. Thus, the input light quantity of the camera 14 is automatically adjusted to an optimum value.