Patent ID: 6801345
Filing Date: 2004-10-05
Classification: H04N

Abstract:
A color image sensor movable relative to a document at least in a secondary scanning direction transverse to a primary scanning direction for reading an image on the document, comprising:a white light emitting diode for emitting white light; a generally sector-shaped prism having a shorter edge surface facing a white light emitting surface of the white light emitting diode and extending longitudinally in the primary scanning direction, a longer edge surface facing a read surface of the document and extending longitudinally in the primary scanning direction, a front surface and a rear surface spaced from each other in the thickness direction of the prism, the front and rear surfaces being so curved as to collect white light emitted from the white light emitting diode onto the read surface of the document; a semiconductor color sensor including a plurality of red light receiving elements spaced from each other in the primary scanning direction, a plurality of blue light receiving elements spaced from each other in the primary scanning direction and a plurality of green light receiving elements spaced from each other in the primary scanning direction for receiving light reflected on the read surface and for simultaneously outputting red, blue and green image signals; and a lens means for forming a non-magnified erect image on the light receiving elements of the semiconductor color sensor in accordance with light reflected on the read surface; wherein the a length of the shorter edge surface of the primary extending longitudinally in the primary scanning direction is shorter than a length of the longer edge surface of the prism extending longitudinally in the primary scanning direction.