IMAGE READING APPARATUS, IMAGE FORMING APPARATUS, AND METHOD OF IMAGE READING

摘要

An image reading apparatus includes a light-emitting device having a peak wavelength that varies depending on a value of a drive current, and illuminates a document with illumination light from the light-emitting device. A light receiving unit receives a light reflected from the document when the illumination light is emitted from the light-emitting device, and converts the received reflected light into image data at a predetermined sensitivity depending on the wavelengths of the received light. A current drive circuit supplies the drive current to turn on the light-emitting device. A wavelength distribution control unit produces two or more durations each having a different value of the drive current by controlling the current drive circuit during each main scanning to the document to produce two or more durations each having a different peak wavelength in each main scanning.