Canon Kabushiki Kaisha

Narumasa Ito

Takayuki Sugiyama

Ikutaro Mitsutake

Akira Matsumoto

Tadao Hayashide

An image reading apparatus according to the present invention includes: a conveyor which conveys an original in a first direction; a light transmitting member which is provided with coating in a first region of a surface facing the original; a reading unit which reads an image at a reading position of the original through the light transmitting member; and a controller which performs processing on the image and which changes the reading position by moving the reading unit when abnormality is detected in the processing. The coating includes a silicon-containing perfluoropolyether compound. An electrically-conductive member is provided in a second region located on the surface of the light transmitting member, upstream of the first region in a conveyance direction of the original. A contact angle of the coating at a position corresponding to the reading position in the first region is appropriately set.

Image reading apparatus

Provided is a light guiding unit including: a light guiding member including an incident surface, an exit surface elongated in a first direction, and a light guiding surface opposed to exit surface; and a diffusion member opposed to light guiding surface, in which: light entering the light guiding member from incident surface is guided via light guiding surface and diffusion member to exit surface, and exits from exit surface to illuminate the original; the light guiding member further includes a plurality of prisms arrayed in first direction on light guiding surface on a side opposed to diffusion member; each of prisms has a rectangular shape in a first section; and each of prisms satisfies the following condition: W tan(sin(1/n))&#x2266;H&#x2266;2W, where W and H represent a width and a height of each of prisms in the first section, respectively, and n represents a refractive index of the light guiding member.

Light guiding unit, and light illuminating device and image reading apparatus using the same

Provided is an image reading apparatus that can inhibit occurrence of a bright spot line image due to microstructures of a light guide. An image reading apparatus satisfies: 45&#x2212;&#x3c6;&#x2266;&#x3b8;&#x2266;&#x3c6;&#x2212;&#x3c9;/n (0&#x2266;&#x3c9;&#x2266;&#x3c9;); and 45&#x2212;&#x3c6;&#x2266;&#x3b8;&#x2266;&#x3c6; (&#x2212;&#x3c9;&#x2266;&#x3c9;&#x2266;0), where &#x3b8; is an angle (deg.) between a surface of original and a reflecting surface of a microstructure reflection surface of a light guide, &#x3c9; is a half angle of view (deg.) of an imaging forming lens, &#x3c9;(&#x3c9;&#x3e;0) is a maximum value (deg.) of the half angle of view of the imaging forming lens on an LED light source side with respect to a reading optical axis of the imaging lens, &#x2212;&#x3c9;is a maximum value (deg.) of the half angle of view of the imaging lens on a side opposite to the LED light source with respect to the reading optical axis, n is a refractive index of the light guide, and &#x3c6;=sin(1/n).

An illumination device and an image reading apparatus having improved heat resistance and spectral characteristics are provided. An illumination device used in an image reading apparatus that moves relative to a read area of a document includes: a light source; a light guide including an incident surface on which light from the light source is incident and an exit surface from which light from the light source exits; and a spectroscopic unit that is provided between the light source and the light guide and includes, on a surface of a glass substrate facing the light source, a multi-layer film for reflecting infrared light toward the light source.

Illumination device and image reading apparatus

An illumination apparatus for use in an image reading apparatus that forms a reduction image of a read area of an original on an image pickup element by an imaging optical system, includes: a light source illuminating the original; and a light guide guiding light to the original; wherein the light guide has a first surface on which light is incident or that diffuses light, a second surface from which light exits toward the read area, and a third and fourth surfaces arranged between the first and second surfaces in a sub-scanning section perpendicular to a longitudinal direction of the light guide, the third surface arranged on a side closer to an optical axis of the imaging optical system, and the fourth surface arranged on a side farther from the optical axis, wherein the third and fourth surfaces are reflective surfaces having the same paraxial power which is appropriately set.

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Utsunomiya, Japan

Narumasa Ito