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GB2021284A - Improved method of electrophotography and apparatus for practicing the same - Google Patents

Improved method of electrophotography and apparatus for practicing the same

Info

Publication number
GB2021284A
GB2021284A GB7911785A GB7911785A GB2021284A GB 2021284 A GB2021284 A GB 2021284A GB 7911785 A GB7911785 A GB 7911785A GB 7911785 A GB7911785 A GB 7911785A GB 2021284 A GB2021284 A GB 2021284A
Authority
GB
United Kingdom
Prior art keywords
image
areas
latent image
contrast
photoconductor
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.)
Granted
Application number
GB7911785A
Other versions
GB2021284B (en
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.)
Savin Corp
Original Assignee
Savin 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
Application filed by Savin Corp filed Critical Savin Corp
Publication of GB2021284A publication Critical patent/GB2021284A/en
Application granted granted Critical
Publication of GB2021284B publication Critical patent/GB2021284B/en
Expired legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00Apparatus for electrographic processes using a charge pattern
    • G03G15/04Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
    • G03G15/045Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with means for charging or discharging distinct portions of the charge pattern on the recording material, e.g. for contrast enhancement or discharging non-image areas

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Wet Developing In Electrophotography (AREA)

Abstract

The invention relates to increasing the effective speed of a photoconductor. The charged photoconductor is deliberately imagewise under exposed to provide a weak latent image of low contrast which is insufficient to make a satisfactory copy. The latent image, however, is sufficient in contrast to enable an optical mask or shield to be provided over the image by toning it. The background or non-image areas of the photoconductor are discharged by ins a blanket illumination of low intensity. The optical mask prevents the image areas from discharging while enhancing the contrast of the weak latent image. The enhanced image is easily developed by any known developing method. The means for producing the optical shield or mask is a development station using usual or special development tone is, which may be liquid-carried or be in dry powdered form. A salient feature of the apparatus is the means for applying developer to the weak latent image. This must be biased to a voltage above that of the background areas and below the potential of the image areas. This ensures that the background areas are unmasked or unshielded while the image areas are masked.
GB7911785A 1978-05-22 1979-04-04 Method of electrophotography and apparatus for practicing the same Expired GB2021284B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US90835578A 1978-05-22 1978-05-22

Publications (2)

Publication Number Publication Date
GB2021284A true GB2021284A (en) 1979-11-28
GB2021284B GB2021284B (en) 1982-08-04

Family

ID=25425651

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7911785A Expired GB2021284B (en) 1978-05-22 1979-04-04 Method of electrophotography and apparatus for practicing the same

Country Status (6)

Country Link
JP (1) JPS554084A (en)
CA (1) CA1129481A (en)
DE (1) DE2920464A1 (en)
FR (1) FR2426930A1 (en)
GB (1) GB2021284B (en)
IT (1) IT1166754B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4278884A (en) * 1978-11-09 1981-07-14 Savin Corporation Method and apparatus for xeroradiography
DE10301735B4 (en) * 2003-01-18 2007-01-18 Deutsches Zentrum für Luft- und Raumfahrt e.V. Method and device for metering microscale particles

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2219005A1 (en) * 1971-04-20 1972-12-21 Iwatsuki Koki Co Ltd Development process for use in electrophotography
US3914609A (en) * 1974-03-04 1975-10-21 Xerox Corp Signal amplification by illumination of a partially developed latent electrostatic image

Also Published As

Publication number Publication date
JPS554084A (en) 1980-01-12
IT7922017A0 (en) 1979-04-19
GB2021284B (en) 1982-08-04
FR2426930A1 (en) 1979-12-21
IT1166754B (en) 1987-05-06
FR2426930B1 (en) 1985-04-05
JPS6251466B2 (en) 1987-10-30
DE2920464C2 (en) 1990-03-08
DE2920464A1 (en) 1979-11-29
CA1129481A (en) 1982-08-10

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Legal Events

Date Code Title Description
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee