Image input device having color filters and filter position detector

摘要

An image input device for inputting a light image of an object with the use of a filter unit having at least two color filters for receiving the light image and separating the light image into the color light components corresponding to the color filter elements. The light image passed through the filter is applied to a charge coupled device for converting the light image to an electrical signal. In order to increase the speed for reading the image of the object, according to one aspect of the invention, there is provided an image input device which includes a Hall IC for detecting a position of each of the color filter elements and outputting a position signal representative of the position of each of the color filter elements, a driver for rotating the filter unit so that the color filter elements selectively receive the light image, phase comparator for comparing the phase of the position signal with that of a vertical sync signal and outputting a comparison signal, and a controller responsive to the comparison signal for controlling the filter driver so that the position signal and the vertical sync signal are in synchronism with each other.