Color image reading device
AssigneeCanon Kabushiki Kaisha
InventorMichitaka Setani
Life of this patent
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Abstract
A color image reading apparatus is provided with a line sensor, an imaging optical system and a blazed diffraction grating. A color image is read by the line sensor through a rotatable reflective one-dimensional blazed diffraction grating serving as the color separation means. At least three color lights color-separated by the diffraction grating is synchronized with the scanning reading speed to rotate the diffraction grating in at least three directions, so that the reading of the color image is conducted by use of one line sensor.
Claims18
A color image reading device comprising:
- a line sensor, said line sensor comprising only a single line sensor;
- an imaging optical system for focusing the image of an object on said line sensor;
- and
- a blazed diffraction grating, positioned between said imaging optical system and said line sensor, for color-separating a light from the object into plural colored lights,
- wherein said blazed diffraction grating is rotatable in a sub scanning direction.
A method of reading a color image, comprising the steps of:
- focusing an image of an object on only a single line sensor by an imaging optical system;
- arranging a blazed diffraction grating for color-separating a light from the object into plural colored lights in an optical path between the imaging optical system and the line sensor;
- and
- rotating the blazed diffraction grating so as to read the image of the object,
- wherein the blazed diffraction grating is rotated in a sub scanning direction.
Dependencies are inferred from the claim text.