Patent EP0268439A2 successfully refreshed from Google Patents.
EP0268439A2
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Image reading apparatus
Assignee: Canon Inc
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Filing: 1987-11-13
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Granted: —
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Expires: 2007-11-13
Abstract
Abstract An image reading apparatus includes a plurality of linear sensors (15) for reading an image of a document. Each linear sensor reads a different portion of a line of the document in a divided manner. A plurality of clamp circuits (75) control black levels of signals generated by the plurality of linear sensors to be a black reference level. A plurality of multipliers (74) control white levels of signals generated by the plurality of linear sensor means which are level-controlled by the clamp circuits (75) so as to be a white reference level.
Inventors
- 👤 Kenichi Suda
- 👤 Shizuo Hasegawa
- 👤 Nobuo Matsuoka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 07:39
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40056; H04N25/00; H04N25/60; H04N25/63; H04N25/633
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
106 words
An image reading apparatus comprising: a plurality of linear sensor means for reading an image of a document, each of said linear sensor means reading a different portion of a line of the document in a divided manner; a plurality of level control means each for varying a level of signal generated by a respective one of said plurality of linear sensor means; and determining means for determining a variation in level of signal by each of said plurality of level control means on the basis of a plurality of reference signals generated by reading a black reference member with said plurality of linear sensor means.
Claim 2
Dependent Claim
106 words
An image reading apparatus comprising: a plurality of linear sensor means for reading an image of a document, each of said linear sensor means reading a different portion of a line of the document in a divided manner; a plurality of level control means each for varying a level of signal generated by a respective one of said plurality of linear sensor means; and determining means for determining a variation in level of signal by each of said plurality of level control means on the basis of a plurality of reference signals generated by reading a black reference member with said plurality of linear sensor means.
Claim 3
Dependent Claim
33 words
An apparatus according to claim 1, wherein said determining means determines a variation in level of signal so that levels of said plurality of reference signals are set to be a predetermined level.
Claim 4
Dependent Claim
23 words
An apparatus according to claim 1, further comprising converting means for converting signals from said plurality of level control means into digital signals.
Claim 5
Dependent Claim
30 words
An apparatus according to claim 1, wherein each of said plurality of linear sensor means reads a color image of a document and generates a plurality of color component signals.
Claim 6
Dependent Claim
20 words
An apparatus according to claim 1, wherein said determining means has storing means for storing the plurality of reference signals.
Claim 7
Dependent Claim
105 words
An image reading apparatus comprising: a plurality of linear sensor means for reading an image of a document, each of said linear sensor means reading a different portion of a line of the document in a divided manner; a plurality of black level control means for controlling black levels of signals generated by said plurality of linear sensor means to be a black reference level; and a plurality of white control means for controlling, white levels of signals generated by said plurality of linear sensor means which are level-controlled by said plurality of black level control means, so as to be a white reference level.
Claim 8
Dependent Claim
105 words
An image reading apparatus comprising: a plurality of linear sensor means for reading an image of a document, each of said linear sensor means reading a different portion of a line of the document in a divided manner; a plurality of black level control means for controlling black levels of signals generated by said plurality of linear sensor means to be a black reference level; and a plurality of white control means for controlling, white levels of signals generated by said plurality of linear sensor means which are level-controlled by said plurality of black level control means, so as to be a white reference level.
Claim 9
Dependent Claim
37 words
An apparatus according to claim 6, wherein said plurality of black level control means perform a control operation on the basis of signals obtained by reading a black reference member using said plurality of linear sensor means.
Claim 10
Dependent Claim
37 words
An apparatus according to claim 6, wherein said plurality of white level control means perform a control operation on the basis of signals obtained by reading a white reference member using said plurality of linear sensor means.
Claim 11
Dependent Claim
30 words
An apparatus according to claim 6, wherein each of said plurality of linear sensor means reads a color image of a document and generates a plurality of color component signals.
Claim 12
Independent Claim
61 words
A method of adjusting an image reading apparatus having a plurality of line sensors for reading respective portions of a line of an image, in which method the line sensors are arranged to read a standard image line and the output signal ranges of the line sensors are independently adjusted in dependence upon the outputs upon reading the standard image line.
Claim 13
Independent Claim
61 words
A method of adjusting an image reading apparatus having a plurality of line sensors for reading respective portions of a line of an image, in which method the line sensors are arranged to read a standard image line and the output signal ranges of the line sensors are independently adjusted in dependence upon the outputs upon reading the standard image line.
References Cited (Backward Citations)
No citation records indexed.
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