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US4952978A Expired / Lapsed US ⏱️ 0.0 years remaining

Speed control of color development in electrophotographic process and apparatus

Assignee: Canon Inc
•
Filing: 1989-07-07
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Granted: 1990-08-28
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Expires: 2009-07-07
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Abstract

Abstract An electrophotographic process using a photosensitive member having an amorphous silicon photosensitive layer, includes uniformly charging the photosensitive member, and exposing the photosensitive member to information light to form an electrostatic latent image, developing the electrostatic latent image using a developing device selected from a plurality of developing devices disposed along a movement direction of the photosensitive member, wherein a movement speed of the photosensitive member is lower when a selected developing device is the one closer to the station where the uniformly charging step is performed than when another developing device is selected, whereby the time periods for a portion of the photosensitive member to move from the charging station to the developing devices is substantially constant.

Inventors

  • 👤 Shigenori Ueda
  • 👤 Koji Yamazaki
  • 👤 Toshiyuki Ehara
  • 👤 Nobuyuki Kume
  • 👤 Nobuo Nakazawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 22:35
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5008; G03G15/01; G03G21/00

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 122 words
An electrophotographic process using a photosensitive member having an amorphous silicon photosensitive layer, comprising: uniformly charging the photosensitive member; exposing the charged photosensitive member to information light to form an electrostatic latent image; and developing the electrostatic latent image using a developing device selected from a plurality of developing devices disposed along a movement direction of the photosensitive member, wherein a movement speed of the photosensitive member is lower when the selected developing device is closer to a station where said uniform charging step is performed than when another developing device further from the charging station is selected, whereby time periods for a portion of the photosensitive member to move from the charging station to the developing devices are substantially the same.
Claim 2
Dependent Claim 122 words
An electrophotographic process using a photosensitive member having an amorphous silicon photosensitive layer, comprising: uniformly charging the photosensitive member; exposing the charged photosensitive member to information light to form an electrostatic latent image; and developing the electrostatic latent image using a developing device selected from a plurality of developing devices disposed along a movement direction of the photosensitive member, wherein a movement speed of the photosensitive member is lower when the selected developing device is closer to a station where said uniform charging step is performed than when another developing device further from the charging station is selected, whereby time periods for a portion of the photosensitive member to move from the charging station to the developing devices are substantially the same.
Claim 3
Dependent Claim 22 words
A process according to claim 1, wherein one of the developing devices contains a black developer and another contains a chromatic developer.
Claim 4
Dependent Claim 15 words
A process according to claim 1, wherein said another developing device contains a red toner.
Claim 5
Dependent Claim 18 words
A process according to claim 1, wherein at least one of said developing devices contains a nonmagnetic toner.
Claim 6
Dependent Claim 124 words
An electrophotographic process using a photosensitive member having an amorphous silicon photosensitive layer, comprising: charging the photosensitive member, and substantially simultaneously exposing the charged photosensitive member to information light to form an electrostatic latent image; and developing the electrostatic latent image using a developing device selected from a plurality of developing devices disposed along a movement direction of the photosensitive member, wherein a movement speed of the photosensitive member is lower when the selected developing device is closer to a station where said image forming step is performed than when another developing device further from the charging station is selected, whereby time periods for a portion of the photosensitive member to move from the charging station to the developing devices are substantially the same.
Claim 7
Dependent Claim 124 words
An electrophotographic process using a photosensitive member having an amorphous silicon photosensitive layer, comprising: charging the photosensitive member, and substantially simultaneously exposing the charged photosensitive member to information light to form an electrostatic latent image; and developing the electrostatic latent image using a developing device selected from a plurality of developing devices disposed along a movement direction of the photosensitive member, wherein a movement speed of the photosensitive member is lower when the selected developing device is closer to a station where said image forming step is performed than when another developing device further from the charging station is selected, whereby time periods for a portion of the photosensitive member to move from the charging station to the developing devices are substantially the same.
Claim 8
Dependent Claim 28 words
A process according to claim 5, wherein the electrostatic latent image is formed by substantially simultaneous application of uniform electric charge and information light to the photosensitive member.
Claim 9
Dependent Claim 22 words
A process according to claim 5, wherein one of the developing devices contains a black developer and another contains a chromatic developer.
Claim 10
Dependent Claim 15 words
A process according to claim 5, wherein said another developing device contains a red toner.
Claim 11
Dependent Claim 18 words
A process according to claim 7, wherein at least one of said developing devices contains a nonmagnetic toner.
Claim 12
Dependent Claim 129 words
An electrophotographic apparatus using a photosensitive member having an amorphous silicon photosensitive layer, comprising: a charger for uniformly charging the photosensitive member; optical means for exposing the charged photosensitive member to information light to form an electrostatic latent image; plural developing devices, disposed along a movement direction of the photosensitive member, for selectively developing the latent images; and speed changing means for changing a movement speed of said photosensitive member so that the movement speed of the photosensitive member is lower when the selected one of the developing devices is closer to the charger than when another developing device further from the charger is selected, whereby the time periods for a portion of the photosensitive member to move from the charger to the developing devices are substantially the same.
Claim 13
Dependent Claim 129 words
An electrophotographic apparatus using a photosensitive member having an amorphous silicon photosensitive layer, comprising: a charger for uniformly charging the photosensitive member; optical means for exposing the charged photosensitive member to information light to form an electrostatic latent image; plural developing devices, disposed along a movement direction of the photosensitive member, for selectively developing the latent images; and speed changing means for changing a movement speed of said photosensitive member so that the movement speed of the photosensitive member is lower when the selected one of the developing devices is closer to the charger than when another developing device further from the charger is selected, whereby the time periods for a portion of the photosensitive member to move from the charger to the developing devices are substantially the same.
Claim 14
Dependent Claim 22 words
An apparatus according to claim 10, wherein one of the developing devices contains a black developer and another contains a chromatic developer.
Claim 15
Dependent Claim 15 words
An apparatus according to claim 10, wherein said another developing device contains a red toner.
Claim 16
Dependent Claim 18 words
An apparatus according to claim 10, wherein at least one of said developing devices contains a nonmagnetic toner.
Claim 17
Dependent Claim 129 words
An electrophotographic apparatus using a photosensitive member having an amorphous silicon photosensitive layer, comprising: image forming means for charging the photosensitive member and substantially simultaneously exposing the charged photosensitive member to information light to form an electrostatic latent image; plural developing devices, disposed along a movement direction of the photosensitive member, for selectively developing the latent images; and speed changing means for changing a movement speed of said photosensitive member so that the movement speed of the photosensitive member is lower when a selected one of the developing devices is the one closer to the latent image forming means than when another developing device is selected, whereby time periods for a portion of the photosensitive member to move from the charger to the developing devices are substantially the same.
Claim 18
Dependent Claim 129 words
An electrophotographic apparatus using a photosensitive member having an amorphous silicon photosensitive layer, comprising: image forming means for charging the photosensitive member and substantially simultaneously exposing the charged photosensitive member to information light to form an electrostatic latent image; plural developing devices, disposed along a movement direction of the photosensitive member, for selectively developing the latent images; and speed changing means for changing a movement speed of said photosensitive member so that the movement speed of the photosensitive member is lower when a selected one of the developing devices is the one closer to the latent image forming means than when another developing device is selected, whereby time periods for a portion of the photosensitive member to move from the charger to the developing devices are substantially the same.
Claim 19
Dependent Claim 113 words
An electrophotographic process using a photosensitive member, comprising: charging the photosensitive member and exposing the charged photosensitive member to information light to form an electrostatic latent image; developing the electrostatic latent image using a developing device selected from a plurality of developing devices disposed along a movement direction of the photosensitive member, wherein a movement speed of the photosensitive member is lower when a selected developing device is closer to a station where said charging is performed than when another developing device further from the charging station is selected, whereby time periods for a portion of the photosensitive member to move from the charging station to the developing devices are substantially the same.
Claim 20
Dependent Claim 113 words
An electrophotographic process using a photosensitive member, comprising: charging the photosensitive member and exposing the charged photosensitive member to information light to form an electrostatic latent image; developing the electrostatic latent image using a developing device selected from a plurality of developing devices disposed along a movement direction of the photosensitive member, wherein a movement speed of the photosensitive member is lower when a selected developing device is closer to a station where said charging is performed than when another developing device further from the charging station is selected, whereby time periods for a portion of the photosensitive member to move from the charging station to the developing devices are substantially the same.

References Cited (Backward Citations)

US4615612A Cited
US4816869A Cited
US4860053A Cited
US4841336A Cited
US4860048A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-08-27 1994-02-26 1994-08-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-08-27 1998-02-26 1998-08-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-08-27 2002-02-26 2002-08-28 $7700.00 Window Closed / Lapsed

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