CLOSELY TIGHTENED IMAGE SENSOR

摘要

PURPOSE:To prevent the end of an original from being erroneously read-out and inputted by providing a light source for an image sensor with a limited curvature, by making both ends of the original which is short of illuminance brought near to the light source relatively and by unniforming the illuminance on the original. CONSTITUTION:An irradiated light 32 from an illumination light source 31 such as a fluorescent lamp having a certain curvature reflects on a transfer original 33. A closely tightened image sensor 30 leads the reflecting light 34 to a photoelectric conversion element on a sensor part 35 through a rod array lens. When a flurorescent light source lamp sets favorably a limited curvature R to a value expressed by an equation (l: effective length in the longitudinal direction of the light source lamp 31 and R(x): curvature radius), effectiveness of shading correction can be obtained easily and inexpensively without using a high-priced light source such as an LED array. Since uniform illumination can be given to the original by utilizing the fluorescent light source lamp with a limited curvature, variable densities of a picture generated due to nonuniformity of an output current of the closely tightened image sensor can be prevented.