Image sensor unit and image reader

An image sensor unit, comprising:

• a light source;
• a light guide that guides light from the light source and linearly emits light to a subject to be illuminated;
• an image-forming element that forms an image of light from the illuminated subject on a photoelectric conversion element;
• a memory circuit that stores plural pieces of reference data to be a reference illuminance of an image region across the illuminated subject according to respective temperature conditions;
• a white reference provided at positions that are at opposite ends of the image-forming element in a longitudinal direction and cover respective areas external to the image region across the illuminated subject;
• a white reference data generation circuit that reads light reflected from the white reference means by the photoelectric conversion element and for generating white reference data that represents a white reference illuminance;
• a correction data generation circuit that calculates a correction coefficient for the image region across the illuminated subject by adopting reference data capable of being approximated to the plural pieces of reference data as correction data that represents a white reference illuminance on the basis of the white reference data;
• and
• a correction circuit that corrects the image data on the basis of the correction coefficient,
• wherein the light guide is made of a material having a region in which transmittance is not constant with respect to wavelength, and
• wherein the light source includes light emission wavelengths in the region of the light guide in which transmittance is not constant and/or in proximity to the region in which transmittance is not constant.

An image sensor unit, comprising:

• a light source;
• a light guide that guides light from the light source and linearly emits light to a subject to be illuminated;
• an image-forming element that forms an image of light from the illuminated subject on a photoelectric conversion element;
• a memory means for storing reference data to be a reference illuminance of an image region across the illuminated subject;
• a white reference provided at a position that is at an opposite side end of the image-forming element in a longitudinal direction away from the light source and covers an area external to the image region across the illuminated subject;
• a white reference data generation circuit that reads light reflected from the white reference means by the photoelectric conversion element and for generating white reference data that represents a white reference illuminance;
• a correction data generation circuit that generates correction data that represents a white reference illuminance of the image region across the illuminated subject on the basis of the white reference data;
• a comparison circuit that calculates a correction coefficient from the correction data and the reference data;
• and
• a correction circuit that corrects the image data on the basis of the correction coefficient,
• wherein the light guide is made of a material having a region in which transmittance is not constant with respect to wavelength, and
• wherein the light source includes light emission wavelengths in the region of the light guide in which transmittance is not constant and/or in proximity to the region in which transmittance is not constant.

An image sensor unit, comprising:

• a light source;
• a light guide that guides light from the light source and linearly emits light to a subject to be illuminated;
• an image-forming element that forms an image of light from the illuminated subject on a photoelectric conversion element;
• a memory circuit that stores plural pieces of reference data to be a reference illuminance of an image region across the illuminated subject according to respective temperature conditions;
• a white reference provided at a position that is at an opposite side end of the image-forming element in a longitudinal direction away from the light source and covers an area external to the image region across the illuminated subject;
• a white reference data generation circuit that reads means for reading light reflected from the white reference means by the photoelectric conversion element and for generating white reference data that represents a white reference illuminance;
• a correction data generation circuit that calculates a correction coefficient for the image region across the illuminated subject by adopting reference data capable of being approximated to the plural pieces of reference data as correction data that represents a white reference illuminance on the basis of the white reference data;
• and
• a correction circuit that corrects the image data on the basis of the correction coefficient,
• wherein the light guide is made of a material having a region in which transmittance is not constant with respect to wavelength, and
• wherein the light source includes light emission wavelengths in the region of the light guide in which transmittance is not constant and/or in proximity to the region in which transmittance is not constant.

An image reader comprising:

• an image sensor unit including a light source, a light guide that guides light from the light source and linearly emits light to a subject to be illuminated, an image-forming element that forms an image of light from the illuminated subject on a photoelectric conversion element, a memory circuit that stores reference data to be a reference illuminance of an image region across the illuminated subject, a white reference circuit provided at positions that are at opposite ends of the image-forming element in a longitudinal direction and cover respective areas external to the image region across the illuminated subject, a white reference data generation circuit that reads light reflected from the white reference means by the photoelectric conversion element and for generating white reference data that represents a white reference illuminance, a correction data generation circuit that generates correction data that represents a white reference illuminance of the image region across the illuminated subject on the basis of the white reference data, a comparison circuit that calculates a correction coefficient from the correction data and the reference data, and a correction circuit that corrects the image data on the basis of the correction coefficient;
• and
• a conveying path configured to convey the subject to be illuminated past the image sensor unit,
• wherein the light guide is made of a material having a region in which transmittance is not constant with respect to wavelength, and
• wherein the light source includes light emission wavelengths in the region of the light guide in which transmittance is not constant and/or in proximity to the region in which transmittance is not constant.

An image reader comprising:

• an image sensor unit including a light source, a light guide that guides light from the light source and linearly emits light to a subject to be illuminated, an image-forming element that forms an image of light from the illuminated subject on a photoelectric conversion element, a memory circuit that stores plural pieces of reference data to be a reference illuminance of an image region across the illuminated subject according to respective temperature conditions, a white reference provided at positions that are at opposite ends of the image-forming element in a longitudinal direction and cover respective areas external to the image region across the illuminated subject, a white reference data generation circuit that reads light reflected from the white reference means by the photoelectric conversion element and for generating white reference data that represents a white reference illuminance, a correction data generation circuit that calculates a correction coefficient for the image region across the illuminated subject by adopting reference data capable of being approximated to the plural pieces of reference data as correction data that represents a white reference illuminance on the basis of the white reference data, and a correction circuit that corrects the image data on the basis of the correction coefficient;
• and
• a conveying path configured to convey the subject to be illuminated past the image sensor unit,
• wherein the light guide is made of a material having a region in which transmittance is not constant with respect to wavelength, and
• wherein the light source includes light emission wavelengths in the region of the light guide in which transmittance is not constant and/or in proximity to the region in which transmittance is not constant.

An image reader comprising:

• an image sensor unit including a light source, a light guide that guides light from the light source and linearly emits light to a subject to be illuminated, an image-forming element that forms an image of light from the illuminated subject on a photoelectric conversion element, a memory circuit that stores reference data to be a reference illuminance of an image region across the illuminated subject, a white reference provided at a position that is at an opposite side end of the image-forming element in a longitudinal direction away from the light source and covers an area external to the image region across the illuminated subject, a white reference data generation circuit that reads light reflected from the white reference means by the photoelectric conversion element and for generating white reference data that represents a white reference illuminance, a correction data generation circuit that generates correction data that represents a white reference illuminance of the image region across the illuminated subject on the basis of the white reference data, a comparison circuit that calculates a correction coefficient from the correction data and the reference data, and a correction circuit that corrects the image data on the basis of the correction coefficient;
• and
• a conveying path configured to convey the subject to be illuminated past the image sensor unit,
• wherein the light guide is made of a material having a region in which transmittance is not constant with respect to wavelength, and
• wherein the light source includes light emission wavelengths in the region of the light guide in which transmittance is not constant and/or in proximity to the region in which transmittance is not constant.

An image reader comprising:

• an image sensor unit including a light source, a light guide that guides light from the light source and linearly emits light to a subject to be illuminated, an image-forming element that forms an image of light from the illuminated subject on a photoelectric conversion element, a memory circuit that stores plural pieces of reference data to be a reference illuminance of an image region across the illuminated subject according to respective temperature conditions, a white reference provided at a position that is at an opposite side end of the image-forming element in a longitudinal direction away from the light source and covers an area external to the image region across the illuminated subject, a white reference data generation circuit that reads means for reading light reflected from the white reference means by the photoelectric conversion element and for generating white reference data that represents a white reference illuminance, a correction data generation circuit that calculates a correction coefficient for the image region across the illuminated subject by adopting reference data capable of being approximated to the plural pieces of reference data as correction data that represents a white reference illuminance on the basis of the white reference data, and a correction circuit that corrects the image data on the basis of the correction coefficient,
• a conveying path configured to convey the subject to be illuminated past the image sensor unit,
• wherein the light guide is made of a material having a region in which transmittance is not constant with respect to wavelength, and
• wherein the light source includes light emission wavelengths in the region of the light guide in which transmittance is not constant and/or in proximity to the region in which transmittance is not constant.