GB1430614A - Radiation sensitive scanning system - Google Patents

Radiation sensitive scanning system

Info

Publication number
GB1430614A
GB1430614A GB5397873A GB5397873A GB1430614A GB 1430614 A GB1430614 A GB 1430614A GB 5397873 A GB5397873 A GB 5397873A GB 5397873 A GB5397873 A GB 5397873A GB 1430614 A GB1430614 A GB 1430614A
Authority
GB
United Kingdom
Prior art keywords
signal
stored
sensitivity
video signal
memory
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB5397873A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US00316337A external-priority patent/US3800079A/en
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of GB1430614A publication Critical patent/GB1430614A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/40Picture signal circuits
    • H04N1/401Compensating positionally unequal response of the pick-up or reproducing head
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V10/00Arrangements for image or video recognition or understanding
    • G06V10/10Image acquisition
    • G06V10/12Details of acquisition arrangements; Constructional details thereof

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Transforming Light Signals Into Electric Signals (AREA)

Abstract

1430614 Scanning system INTERNATIONAL BUSINESS MACHINES CORP 21 Nov 1973 [18 Dec 1972] 53978/73 Heading H4F [Also in Division G1] To compensate for variations in the sensitivities of the individual photo-diodes in a photodiode array, e.g. a self-scanned linear array 25 of photo-diodes analysing light reflected from a moving document 14, the array is initially arranged to scan a standard background or white level which may be in the form of a document or a bedplate, and the resulting sensitivity video signal which represents non-uniformity in sensitivity and in illumination is stored and used to correct subsequent video information signals. The integrated 30 sensitivity video signal has a fixed grey level signal from source 32 subtracted, 35, therefrom, is digitized in A-D converter 40 and stored in memory 50, e.g. a shift register. During scanning of an information document these stored signals are read-out from the memory 50, D-A converted, 55, and added, 60, to the fixed grey level signal from source 32, the difference between resulting sensitivity video signal and the serial video information signal being derived in differential amplifier 65 and then divided by the sensitivity video signal in circuit 70 to produce at output 75 a compensated serial video information signal which may be fed via a threshold circuit to a utilization system such as a recognition, reproduction or processing system. To compensate for photo-diode leakage current non-uniformity, correction signals derived by initially scanning a black level may also be stored and subsequently read-out. Memory 50 and converters 40 and 55 may be replaced by an analogue shift register.
GB5397873A 1972-12-18 1973-11-21 Radiation sensitive scanning system Expired GB1430614A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00316337A US3800079A (en) 1972-12-18 1972-12-18 Compensation for a scanning system

Publications (1)

Publication Number Publication Date
GB1430614A true GB1430614A (en) 1976-03-31

Family

ID=23228625

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5397873A Expired GB1430614A (en) 1972-12-18 1973-11-21 Radiation sensitive scanning system

Country Status (3)

Country Link
DE (1) DE2353299A1 (en)
FR (1) FR2213590B1 (en)
GB (1) GB1430614A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2126829A (en) * 1982-09-09 1984-03-28 Link Electronics Ltd Image correction
EP0164222A1 (en) * 1984-05-09 1985-12-11 Xerox Corporation Pixel non-uniformity correction system
GB2316259A (en) * 1996-08-12 1998-02-18 Alps Electric Co Ltd Shading correction

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5660165A (en) * 1979-10-20 1981-05-23 Canon Inc Picture reader
US4524388A (en) * 1981-08-11 1985-06-18 Konishiroku Photo Industry Co., Ltd. Shading correction device
US4675533A (en) * 1982-07-22 1987-06-23 Canon Kabushiki Kaisha Image reading apparatus with image data overlap removal
DE3448555C2 (en) * 1983-03-06 2001-08-09 Canon Kk Color image reader
DE3408107C2 (en) 1983-03-06 1996-05-30 Canon Kk Halftone color image recorder
JPS6054571A (en) * 1983-09-05 1985-03-29 Fuji Photo Film Co Ltd Picture scanning reader
US4691241A (en) * 1983-12-06 1987-09-01 Dainippon Screen Mfg. Co., Ltd. Method and system for compensating for a shading phenomenon
US4767927A (en) * 1984-08-16 1988-08-30 Kabushiki Kaisha Toshiba Apparatus for reading radiation image information stored in imaging plate
US4731661A (en) * 1984-11-16 1988-03-15 Sharp Kabushiki Kaisha Color document reader with white balance adjuster for determining light emission periods for a plurality of different-colored light sources and corresponding integration times for a light sensor by reading a white reference area
JPS62293384A (en) * 1986-06-11 1987-12-19 Toshiba Corp Picture input device

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2126829A (en) * 1982-09-09 1984-03-28 Link Electronics Ltd Image correction
EP0164222A1 (en) * 1984-05-09 1985-12-11 Xerox Corporation Pixel non-uniformity correction system
GB2316259A (en) * 1996-08-12 1998-02-18 Alps Electric Co Ltd Shading correction
US6075621A (en) * 1996-08-12 2000-06-13 Apls Electric Co., Ltd. Image sensing apparatus and shading correction method
GB2316259B (en) * 1996-08-12 2000-09-06 Alps Electric Co Ltd Image sensing apparatus and shading correction method

Also Published As

Publication number Publication date
DE2353299A1 (en) 1974-06-27
FR2213590B1 (en) 1977-09-23
FR2213590A1 (en) 1974-08-02

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee