US 6,728,010 B1Granted

Color image reader for use in image forming apparatus

AssigneesKabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha

InventorKazuyoshi Tsutsumi

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Abstract

An color image reader according to the present invention includes a holding glass for holding an object, the holding glass being a rectangular, plate-like, flat member having a pair of long sides and a pair of short sides perpendicular to each other at right angles, an illuminating unit having an xenon lamp and a reflector both for illuminating the object placed closely on one side of the holding glass, the xenon lamp emitting light toward an irradiation range to irradiate the object, and the reflector having a first reflection plane and a second reflection plane to irradiate the irradiation range in a direction along the planes of the holding glass from a direction opposite to a direction of the light emitted from the xenon lamp, a reduction lens for providing an image-forming characteristic to light reflected by the object on the holding member illuminated by the illuminating unit, and a CCD sensor for receiving the reflected light to which the reduction lens provides the image-forming characteristic, and outputting an electrical signal corresponding to the reflected light. Even though a document to be read is formed by pasting two sheets and thus has a step, a shade can be prevented from occurring in the step.

Claims4

Dependent claims

An image reader comprising:

a holding glass to hold an object to be read, the holding glass being a rectangular, plate-like, flat plate having two pairs of sides that intersect each other at right angles;
an illuminating unit, including a tube-like lamp and provided in parallel with one of the two pairs of sides of the holding glass to emit a light and illuminate an area having a given range on the holding glass;
and
a reflector, provided along the lamp of the illuminating unit, to receive the light from the illuminating unit and reflect the light toward an irradiation range from a direction opposite to a direction of the light emitted from the illuminating unit in order to irradiate the holding glass, the reflector being a flat member which is folded once in a direction parallel with the one of the two pairs of sides of the holding glass, to have a first reflection plane and a second reflection plane, an angle between the first reflection plane and a center of irradiation on the holding glass being smaller than that between the second reflection plane and the center of irradiation on the holding glass, the first reflection plane of the reflector being located such that the angle between the first reflection plane and the center of irradiation on the holding glass ranges from 22.5° to 26.5°, and the second reflection plane of the reflector being located such that an angle between the second reflection plane and the center of irradiation on the holding glass ranges from 33° to 37.5°;
a converging lens to converge the light reflected by the object on the holding glass illuminated by the illuminating unit and the reflector;
and
a CCD sensor to receive the light focused by the focusing lens and outputting an electrical signal corresponding to the received light.

4 more elements

An image forming apparatus comprising:

an image reader including:
a holding glass to hold an object to be read, the holding glass being a rectangular, plate-like, flat plate having two pairs of sides intersecting each other at right angles;
an illuminating unit, including a tube-like lamp and provided in parallel with one of the two pairs of sides of the holding glass to emit a light and illuminate an area having a given range on the holding glass;
and
a reflector, provided along the lamp of the illuminating unit, to receive the light from the illuminating unit and reflect the light toward an irradiation range from a direction opposite to a direction of the light emitted from the illuminating unit in order to irradiate the holding glass, the reflector being a flat member which is folded once in a direction parallel with the one of the two pairs of sides of the holding glass, to have a first reflection plane and a second reflection plane, an angle between the first reflection plane and a center of irradiation on the holding glass being smaller than that between the second reflection plane and the center of irradiation on the holding glass, the first reflection plane of the reflector being located such that the angle between the first reflection plane and the center of irradiation on the holding glass ranges from 22.5° to 26.5°, and the second reflection plane of the reflector being located such that an angle between the second reflection plane and the center of irradiation on the holding glass ranges from 33° to 37.5°;
a converging lens to converge the light reflected by the object on the holding glass illuminated by the illuminating unit and the reflector;
a CCD sensor to receive the light focused by the focusing lens and outputting an electrical signal corresponding to the received light;
an exposing unit to emit exposure light, whose intensity varies with an output image signal generated from the image reader, to a predetermined position;
an image forming unit having a photo-sensitive body serving as a light acceptor, a developing unit capable of selectively supplying a visualizing material to the photo-sensitive body, and a transfer unit for transferring the visualizing material from the photo-sensitive drum to an image-transferred member, to form a visualizing-material image by supplying the visualizing material by the developing unit to a latent image formed on the photo-sensitive body by the exposure light emitted from the exposing unit;
an image-transferred member feeding mechanism to feed the image-transferred member to the transfer unit to transfer the visualizing-material member formed by the developing unit by the transfer unit of the image forming unit;
and
a fixing unit for fixing the visualizing-material image on the image-transferred member fed by the image-transferred member feeding mechanism.

9 more elements

Dependencies are inferred from the claim text.