US4593989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Charge removing device for an electrophotographic copying machine
Assignee: Sharp Corp
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Filing: 1984-06-01
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Granted: 1986-06-10
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Expires: 2004-06-01
Abstract
Abstract An electrophotographic copying machine comprises a light beam reflection device, a charge removing device, a developing device, and a control device. The light beam reflection device is operated to reflect light beams from a document image portion and a margin portion to a photoreceptor. The control device causes the charge removing device to remove unnecessary charges in order to erase a latent image corresponding to the margin portion. The developing device is operated to develop the latent image exactly corresponding to the document portion. The control device may comprise a timer or lead switches.
Inventors
- 👤 Katsuyoshi Fujiwara
- 👤 Hiroshi Uchiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:09
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/045; G03G15/047; G03G2215/00; G03G2215/04; G03G2215/0429; G03G2215/0468; G03G2215/047; G03G2215/0473
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
175 words
A charge removing system for removing charges from a surface of a photoreceptor means to develop a latent image on said photoreceptor means in an electrophotographic copying machine comprising: a light incident means for directing light beams toward said photoreceptor means, said light beams being reflected from a document to be copied including areas producing false images, such as document edges and a document gutter margin; a charge removing means for removing unnecessary charges from said surface of said photoreceptor means, said unnecessary charges corresponding to said area of said document producing said false images; and a control means for controlling the activation of said charge removing means said control means comprising a timer means for counting a time of moving said light incident means between a position of scanning the document and a position of scanning the false image producing areas, such as said document edges and document margin, and a lead switch means for sensing whether said document is being scanned or said false image producing areas including said margin is being scanned.
Claim 2
Dependent Claim
175 words
A charge removing system for removing charges from a surface of a photoreceptor means to develop a latent image on said photoreceptor means in an electrophotographic copying machine comprising: a light incident means for directing light beams toward said photoreceptor means, said light beams being reflected from a document to be copied including areas producing false images, such as document edges and a document gutter margin; a charge removing means for removing unnecessary charges from said surface of said photoreceptor means, said unnecessary charges corresponding to said area of said document producing said false images; and a control means for controlling the activation of said charge removing means said control means comprising a timer means for counting a time of moving said light incident means between a position of scanning the document and a position of scanning the false image producing areas, such as said document edges and document margin, and a lead switch means for sensing whether said document is being scanned or said false image producing areas including said margin is being scanned.
Claim 3
Dependent Claim
48 words
The system of claim 1, wherein said charge removing means is positioned between a first charger means and latent image development means, said first charger means being provided for uniformly charging the surface of said photoreceptor means and said developing means being provided for developing said latent image.
Claim 4
Dependent Claim
49 words
The system of claim 2, wherein said charge removing means is positioned adjacent a second charger means for uniformly charging the surface of said photoreceptor means to a polarity opposite to that charged by said first charger means for initially and uniformly charging the surface of said photoreceptor means.
Claim 5
Dependent Claim
15 words
The system of claim 1, further comprising a control switch for selecting said control 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) | 1989-06-09 | 1989-12-09 | 1990-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-09 | 1993-12-09 | 1994-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-09 | 1997-12-09 | 1998-06-10 | $7700.00 | Window Closed / Lapsed |