Image reading apparatus with illumination timing control

Abstract

An image reading apparatus for reading an image by radiating the light onto an original includes a photosensor array the photosensors of which are arranged along the width of the original and receive the light scattered from the original surface and convert that light into electric signals. A period of time from the time when the photosensors receive the light until outputs containing the read information are derived cannot be ignored as compared with a reading scan time when the signals are read from the photosensor. A light source is arranged along the width of the original and is divided into a plurality of. A light-on controller for lighting the blocks of the light source to illuminate pixels for the reading of an image on the original, in advance of the reading of the pixels, for a time interval over neater than the foregoing period of time. In this apparatus, only a single LED array is used, so that the arrangement of the apparatus is simplified and the cost of the apparatus and its operating cost are also reduced.

Dependencies are inferred from the claim text.