IMAGE READING POSITION ADJUSTING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain a device which easily adjusts image reading by reading light from a chart which has a black area and areas other than black and adjusting image forming conditions of the light of a read part on the basis of the light from the read chart. SOLUTION: Before or when an original on original platen glass is scanned, a scanning mirror is moved to read an image of an adjusting chart. The out-of- focus quantity (resolving power) of the adjusting chart is judged by a CPU 131 and the corresponding defocusing quantity is calculated. The positions of a lens 105 and a CDD 153 are moved by using a lens fine adjusting device 151 and a CCD fine adjusting device 155 according to the calculated defocusing quantity. Consequently, the image is formed in focus. Optical system chromatic aberration does not occur because of providing a filter which transmits only specified wavelength light at the front or back position of the lens 105 and using the specified wavelength light by the filter for adjusting the image forming position.