Patent US4978998A successfully refreshed from Google Patents.
US4978998A
Expired / Lapsed
US
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Image transferring device for image forming equipment
Assignee: Ricoh Co Ltd
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Filing: 1990-04-20
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Granted: 1990-12-18
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Expires: 2010-04-20
Abstract
Abstract An image transferring device for use in image forming equipment prevents an image from being omitted in a trailing edge portion of a paper sheet in the event when pre-transfer discharge is applied to a photoconductive element prior to image transfer. The pre-transfer discharge is not effected on an image portion of a photoconductive element that is associated with a trailing edge portion of a paper sheet where a discharge due to separation will be caused by the vibration of the trailing edge portion of the paper sheet.
Inventors
- 👤 Hideo Aizawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:31
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; G03G15/169
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
146 words
A device for use in image forming equipment for transferring a toner image developed by a developing device on a photoconductive element to a paper sheet which is transported to an image transfer station by a register roller pair and guide means having a discontinuous portion, said device comprising: pre-transfer discharging means adjoining a peripheral surface of the photoconductive element and located between the developing device and the image transfer station; and transferring and separating means for transferring the toner image to the paper sheet and separating said paper sheet from the photoconductive element; said pre-transfer discharging means having been turned off when a leading edge portion of the paper sheet moves away from the discontinuous portion of the guide means and a portion of the photoconductive element that should reach the image transfer station moves away from a position where said pre-transfer discharging means acts.
Claim 2
Independent Claim
146 words
A device for use in image forming equipment for transferring a toner image developed by a developing device on a photoconductive element to a paper sheet which is transported to an image transfer station by a register roller pair and guide means having a discontinuous portion, said device comprising: pre-transfer discharging means adjoining a peripheral surface of the photoconductive element and located between the developing device and the image transfer station; and transferring and separating means for transferring the toner image to the paper sheet and separating said paper sheet from the photoconductive element; said pre-transfer discharging means having been turned off when a leading edge portion of the paper sheet moves away from the discontinuous portion of the guide means and a portion of the photoconductive element that should reach the image transfer station moves away from a position where said pre-transfer discharging means acts.
Claim 3
Dependent Claim
50 words
A device as claimed in claim 1, wherein a timing for turning off said pre-transfer discharging means is deviated by a predetermined period of time from a timing at which a register sensor located immediately before the register roller pair will sense the leading edge portion of the paper sheet.
Claim 4
Dependent Claim
24 words
A device as claimed in claim 1, wherein a timing for turning off said pre-transfer discharging means is variable in a plurality of steps.
Claim 5
Dependent Claim
23 words
A device as claimed in claim 1, wherein a transfer current is increased at a timing for turning off said pre-transfer discharging means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-17 | 1994-06-18 | 1994-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-17 | 1998-06-18 | 1998-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-17 | 2002-06-18 | 2002-12-18 | $7700.00 | Window Closed / Lapsed |