Driving device of light source

Abstract

The object of the invention is to extend the life of the light source while uniformizing the illuminance intensity in the main scanning direction. The invention is based on a light source of image reading apparatus comprised of film layers laminated on a transparent substrate in the order of a transparent electrode, an area light emitter and a metal electrode, and emitting light by impressing a specific voltage on these two electrodes. And an area light emitter column configured by arranging area light emitters corresponding to each color of R (red), G (green) and B (blue) in the sub scanning direction, or a monochrome area light emitter is arranged repeatedly in the main scanning direction. Accordingly, even when somewhere in the light emitting element has a defect like the film thickness is thin, the current gathering at this point with the low resistance value becomes a very small volume. Therefore, it would not occur that the film burns out from here.

Dependencies are inferred from the claim text.