Patent ID: 7411177

Claim:
A multi-spectrum image capturing device comprising: a multi-spectrum illuminating device for irradiating lights of different wavelengths to an irradiated surface; and an image-capturing optical system for forming an image based on lights reflected from the irradiated surface under illumination by the multi-spectrum illuminating device; wherein components of the reflected lights captured via the image-capturing optical system are analyzed to measure color components of the irradiated surface; and wherein the multi-spectrum illuminating device comprises: a plurality of light sources for emitting the lights of different wavelengths; and a pair of fiber units, each of which comprises a plurality of optical fibers which are divided at a light input side of the fiber unit into a plurality of input light bundles corresponding to a plurality of the light sources, and which are bundled at a light output side of the fiber unit into an output light bundle in which the optical fibers constituting the input light bundles are shuffled at random; wherein the pair of the fiber units are provided so as to be opposed to the image-capturing optical system and so as to be separated from each other; and wherein each of the pair of the fiber units comprises a first optical sheet, which is disposed on an exit-side surface of the output light bundle and through which the lights are transmitted, and which has a gradation characteristic which is reversed with respect to a luminance distribution of illumination unevenness on the irradiated surface, in order to reduce the illumination unevenness on the irradiated surface.