US 5,398,061 AGranted

Light source switching type color image scanner

AssigneeSony Corporation

InventorsHisanori Miura, Tadakuni Narabu, Masahide Hirama

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Abstract

The present invention is directed to a light source switching type color image scanner in which a color signal can be read out at high speed by reducing a read-out time. A red light source (3), a green light source (4) and a blue light source (5) which can be selectively switched are disposed under an original document holder (1) on which an original document (2) is held. Further, there are disposed a mirror (7) and a lens (8) which are used to focus a reflected image of the original document (2) onto a CCD linear image sensor (6). The CCD linear image sensor (6) includes a shutter gate (12) and a shutter drain (13) which are used to reset signal charges of remaining lights from the respective light sources (3), (4) and (5). The reset of a signal charge begins before a next color light source is energized.

Claims6

Dependent claims

A color image reading apparatus for reading a color document, comprising:

a plurality of light sources for emitting light of respective different colors onto the document;
a CCD sensor for receiving a light reflected from the document and for reading out an image of the document, said CCD sensor comprising a sensor section including an array of a plurality of sensor elements, a charge transfer section disposed on one side of the sensor section for reading out signal charges from the sensor section through a read-out gate, a shutter drain disposed on another side of the sensor section for discharging signal charges generated by a remaining light left after emission of the respective light sources through a shutter gate;
and
means for providing shutter pulses to the shutter gate so that each of the shutter pulses rises substantially while turning off the corresponding light source.

1 more element

Dependencies are inferred from the claim text.