Light-source device for exposure and light-source device for image reading

A light-source device for irradiating the surface of an original with light while being moved relative to the original and focusing light reflected from or transmitted through the surface of the original onto a photosensitive material so as to subject the photosensitive material to slit exposure, comprising:

• light-emitting elements for producing three colors having light-emitting wavelengths different from each other,
• said three-color light-emitting elements being linearly arranged at predetermined intervals and disposed at a right angle to the direction in which said original is conveyed,
• said three-color light-emitting elements being respectively set in number based on a ratio between outputs of said three-color light-emitting elements at their light-emitting wavelengths when said three-color light-emitting elements are caused to emit light at the maximum rated outputs and a ratio between sensitivities of the photosensitive material at the light-emitting wavelengths in such a manner that when said three-color light-emitting elements are caused to emit light at the maximum rated outputs, densities of colors on the photosensitive material, which are color-developed by said three-color light-emitting elements, are substantially identical to each other.

A light-source device for irradiating the surface of an original with light while being moved relative to the original and focusing light reflected from or transmitted through the surface of the original onto an image reading means so as to read an image of said original, comprising:

• light-emitting elements for producing three colors having light-emitting wavelengths different from each other,
• said three-color light-emitting elements being linearly arranged at predetermined intervals and disposed at a right angle to the direction in which said original is conveyed,
• said three-color light-emitting elements being respectively set in number based on a ratio between outputs of said three-color light-emitting elements at their light-emitting wavelengths when said three-color light-emitting elements are caused to emit light at the maximum rated outputs and a ratio between sensitivities of the image reading means at the light-emitting wavelengths in such a manner that when at least said two-color light-emitting elements of said three-color light-emitting elements are caused to emit light at the maximum rated outputs, densities of colors produced by said three-color light-emitting elements, which have been read by the image reading means, are substantially identical to each other.