IMAGE READING OPTICAL SYSTEM UNIT

摘要

PROBLEM TO BE SOLVED: To provide an image reading optical system unit which is always maintained constant in the spacing between a light source and an original or contact glass on which the original is placed and which is capable of exactly reading the original image in reading the image of the original placed on the contact glass by scanning and driving the light source. SOLUTION: This image reading optical system unit consists of a rigid frame which has an opening for arranging the contact glass for placement of the original atop the frame and a carriage which is arranged within this frame and is scanned and driven by wire or belt driving and is provided with the light source for illuminating the original placed on the contact glass with the light in the carriage, in which the wall surface of the frame descends downward in a pair of side parts facing each other at the peripheral edge of the above opening formed atop the frame and a guide rail extending inward in a horizontal direction from the bottom end thereof is formed integrally with the frame.