Patent US2181294A successfully refreshed from Google Patents.
US4023894A
Expired / Lapsed
US
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Transfer apparatus
Assignee: Xerox Corp
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Filing: 1975-07-11
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Granted: 1977-05-17
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Expires: 1995-07-11
Abstract
Abstract Copying apparatus in which an image of charged particles of imaging material is transferred from one supporting surface to a sheet of support material, while the sheet of support material is held on an apertured vacuum belt and an electrical transfer field is applied thereto, where the vacuum belt comprises electrically relaxable material to prevent print-out of the vacuum apertures on the support material. The coping apparatus includes a multiple registered transfer system for color copying with reciprocating of the supporting vacuum belt.
Inventors
- 👤 Narendra S. Goel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:41
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; G03G15/163; G03G15/1635; G03G15/165; G03G15/1655; G03G15/01; G03G15/0105; G03G15/0131; Y; Y10; Y10S; Y10S101/00; Y10S101/37
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
240 words
In an electrostatographic printing system in which an image of imaging material on an image supporting member is transferred at a transfer station to copy sheets using electrical transfer fields generated by an electrical transfer corona charge generator, and wherein a copy sheet supporting belt with front and rear sides transports said copy sheets through said transfer station for said image transfer with said copy sheets supported on said front side of said belt for transfer juxtaposition with said image supporting member, the improvement wherein: said copy sheet supporting belt comprises a thin solid uniform material of a thickness of approximately 0.76 to 2 millimeters between said front and rear sides and having a multiplicity of vacuum apertures between said front and rear sides with openings of greater than approximately 0.5 millimeters; vacuum means are provided for applying vacuum forces through said copy sheet supporting belt vacuum apertures from the rear side of said belt to retain a copy sheet on said front side of said belt in said transfer station; said transfer corona generator faces, but is spaced from, said rear side of said copy sheet supporting belt to apply transfer charges to said rear side of said belt, and said copy sheet supporting belt comprises an electrically relaxable material for resistively conducting said transfer charges from said rear side to said front side of said belt in said transfer station to avoid transfer discontinuities from said vacuum apertures.
Claim 2
Dependent Claim
240 words
In an electrostatographic printing system in which an image of imaging material on an image supporting member is transferred at a transfer station to copy sheets using electrical transfer fields generated by an electrical transfer corona charge generator, and wherein a copy sheet supporting belt with front and rear sides transports said copy sheets through said transfer station for said image transfer with said copy sheets supported on said front side of said belt for transfer juxtaposition with said image supporting member, the improvement wherein: said copy sheet supporting belt comprises a thin solid uniform material of a thickness of approximately 0.76 to 2 millimeters between said front and rear sides and having a multiplicity of vacuum apertures between said front and rear sides with openings of greater than approximately 0.5 millimeters; vacuum means are provided for applying vacuum forces through said copy sheet supporting belt vacuum apertures from the rear side of said belt to retain a copy sheet on said front side of said belt in said transfer station; said transfer corona generator faces, but is spaced from, said rear side of said copy sheet supporting belt to apply transfer charges to said rear side of said belt, and said copy sheet supporting belt comprises an electrically relaxable material for resistively conducting said transfer charges from said rear side to said front side of said belt in said transfer station to avoid transfer discontinuities from said vacuum apertures.
Claim 3
Dependent Claim
50 words
The electrostatographic printing system of claim 1, wherein said belt has a resistivity of between approximately (3.5 × 10 11 )/K ohm-centimeters and (8.3 × 10 9 T 2 )/K ohm-centimeters, where T is the belt thickness measured in millimeters, and K is the dielectric constant of the belt material.
Claim 4
Dependent Claim
11 words
The electrostatographic printing system of claim 2, wherein K is 1.
Claim 5
Dependent Claim
37 words
The electrostatographic printing system of claim 1, wherein pneumatic baffle means are provided to shield said transfer corona generator from said vacuum means to prevent interference in the charging of said belt by said transfer corona generator.
Claim 6
Dependent Claim
35 words
The electrostatographic printing system of claim 1, wherein another corona generator means is positioned closely adjacent said transfer corona generator to at least partially neutralize charges placed on said belt by said transfer corona generator.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |