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EP0383307A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Image reading apparatus

Assignee: Canon Inc
•
Filing: 1990-02-14
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Granted: —
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Expires: 2010-02-14
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Abstract

Abstract An image reading apparatus comprises a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate, a focusing optical system for focusing an object image on the multiline sensor and a blazed diffraction grating, disposed in an optical path between the focusing optical system and the multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays. The grating thickness of the blazed diffraction grating is changed in correspondence with an angle of light incident on the blazed diffraction grating.

Inventors

  • 👤 Takehiko Nakai
  • 👤 Michitaka Setani

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 02:12
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/48; H04N1/486; H04N1/488

Claims Analysis

Total Claims: 32
Claim 1
Independent Claim 100 words
An image reading apparatus comprising: a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, a grating thickness of said blazed diffraction grating being changed in correspondence with an angle of light incident on said blazed diffraction grating.
Claim 2
Dependent Claim 100 words
An image reading apparatus comprising: a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, a grating thickness of said blazed diffraction grating being changed in correspondence with an angle of light incident on said blazed diffraction grating.
Claim 3
Dependent Claim 41 words
An apparatus according to claim 1, wherein said multiline sensor includes a plurality of lines of linear sensor arrays which are arranged to be separated in a direction perpendicular to an array direction of said sensor arrays by a finite distance.
Claim 4
Dependent Claim 34 words
An apparatus according to claim 1, wherein said blazed diffraction grating color-separates light from the object into a plurality of light components in a direction perpendicular to an array direction of said sensor arrays.
Claim 5
Dependent Claim 30 words
An apparatus according to claim 1, wherein the grating thickness of said blazed diffraction grating is changed in correspondence with a field angle with respect to said focusing optical system.
Claim 6
Dependent Claim 39 words
An apparatus according to claim 1, wherein the grating thickness of said blazed diffraction grating is changed in correspondence with a field angle of a principal ray of light from the object and incident on said blazed diffraction grating.
Claim 7
Dependent Claim 25 words
An apparatus according to claim 2, wherein the object is scanned in a sub scanning direction perpendicular to the array direction of said sensor arrays.
Claim 8
Dependent Claim 24 words
An apparatus according to claim 6, wherein a sensor surface of said multiline sensor is arranged to be parallel to the sub scanning direction.
Claim 9
Dependent Claim 17 words
An apparatus according to claim 1, wherein said blazed diffraction grating comprises a linear blazed diffraction grating.
Claim 10
Dependent Claim 34 words
An apparatus according to claim 1, wherein said multiline sensor is curved so that an optical path length between said multiline sensor and said blazed diffraction grating is constant over the entire field angle.
Claim 11
Dependent Claim 40 words
An apparatus according to claim 9, wherein a grating pitch of said blazed diffraction grating is not changed in correspondence with a field angle of a principal ray of light form the object and incident on said blazed diffraction grating.
Claim 12
Dependent Claim 109 words
An image reading apparatus comprising: a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, a grating pitch of said blazed diffraction grating being changed in correspondence with a field angle of a principal ray of light from the object and incident on said blazed diffraction grating.
Claim 13
Dependent Claim 109 words
An image reading apparatus comprising: a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, a grating pitch of said blazed diffraction grating being changed in correspondence with a field angle of a principal ray of light from the object and incident on said blazed diffraction grating.
Claim 14
Dependent Claim 41 words
An apparatus according to claim 11, wherein said multiline sensor includes a plurality of lines of linear sensor arrays which are arranged to be separated in a direction perpendicular to an array direction of said sensor arrays by a finite distance.
Claim 15
Dependent Claim 34 words
An apparatus according to claim 11, wherein said blazed diffraction grating color-separates light from the object into a plurality of light components in a direction perpendicular to an array direction of said sensor arrays.
Claim 16
Dependent Claim 25 words
An apparatus according to claim 12, wherein the object is scanned in a sub scanning direction perpendicular to the array direction of said sensor arrays.
Claim 17
Dependent Claim 24 words
An apparatus according to claim 14, wherein a sensor surface of said multiline sensor is arranged to be parallel to the sub scanning direction.
Claim 18
Dependent Claim 17 words
An apparatus according to claim 11, wherein said blazed diffraction grating comprises a linear blazed diffraction grating.
Claim 19
Dependent Claim 133 words
An image reading apparatus comprising: a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, a grating thickness of said blazed diffraction grating being changed in correspondence with an angle of light incident on said blazed diffraction grating, and a grating pitch of said blazed diffraction grating being changed in correspondence with a field angle of a principal ray of light from the object and incident on said blazed diffraction grating.
Claim 20
Dependent Claim 133 words
An image reading apparatus comprising: a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, a grating thickness of said blazed diffraction grating being changed in correspondence with an angle of light incident on said blazed diffraction grating, and a grating pitch of said blazed diffraction grating being changed in correspondence with a field angle of a principal ray of light from the object and incident on said blazed diffraction grating.
Claim 21
Dependent Claim 105 words
An image reading apparatus comprising: a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, wherein said multiline sensor is curved so that an optical path length between said multiline sensor and said blazed diffraction grating is constant over the entire field angle.
Claim 22
Dependent Claim 105 words
An image reading apparatus comprising: a multiline sensor on which a plurality of linear sensor arrays are arranged on a single substrate; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, wherein said multiline sensor is curved so that an optical path length between said multiline sensor and said blazed diffraction grating is constant over the entire field angle.
Claim 23
Dependent Claim 40 words
An apparatus according to claim 18, wherein a grating pitch of said blazed diffraction grating is not changed in correspondence with a field angle of a principal ray of light from the object and incident on said blazed diffraction grating.
Claim 24
Dependent Claim 115 words
An image reading apparatus comprising: a multiline sensor including a plurality of lines of linear sensor arrays which are arranged to be separated in a direction perpendicular to an array direction of said sensor arrays by a finite distance; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, said blazed diffraction grating being curved along the array direction so that a concave surface thereof faces said focusing optical system.
Claim 25
Dependent Claim 115 words
An image reading apparatus comprising: a multiline sensor including a plurality of lines of linear sensor arrays which are arranged to be separated in a direction perpendicular to an array direction of said sensor arrays by a finite distance; a focusing optical system for focusing an object image on said multiline sensor; and a blazed diffraction grating, disposed in an optical path between said focusing optical system and said multiline sensor, for color-separating light from the object into a plurality of light components and guiding the color-separated light components to the corresponding sensor arrays, said blazed diffraction grating being curved along the array direction so that a concave surface thereof faces said focusing optical system.
Claim 26
Dependent Claim 40 words
An. apparatus according to claim 20, wherein a grating thickness of said blazed diffraction grating is not changed in correspondence with a field angle of a principal ray of light from the object and incident on said blazed diffraction grating.
Claim 27
Dependent Claim 34 words
An apparatus according to claim 20, wherein said blazed diffraction grating color-separates light from the object into a plurality of light components in a direction perpendicular to the array direction of said sensor arrays.
Claim 28
Dependent Claim 25 words
An apparatus according to claim 20, wherein the object is scanned in a sub scanning direction perpendicular to the array direction of said sensor arrays.
Claim 29
Dependent Claim 24 words
An apparatus according to claim 23, wherein a sensor surface of said multiline sensor is arranged to be parallel to the sub scanning direction.
Claim 30
Dependent Claim 17 words
An apparatus according to claim 20, wherein said blazed diffraction grating comprises a linear blazed diffraction grating.
Claim 31
Dependent Claim 39 words
An apparatus according to claim 20, wherein a grating pitch of said blazed diffraction grating is changed in correspondence with a field angle of a principal ray of light from the object and incident on said blazed diffraction grating.
Claim 32
Dependent Claim 39 words
An apparatus according to claim 20, wherein a grating pitch of said blazed diffraction grating is changed in correspondence with an exit angle of light output from said focusing optical system, which changes in accordance with a field angle.

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