Patent US3751157A successfully refreshed from Google Patents.
US3751157A
Expired / Lapsed
US
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Electrographic printer
Assignee: Varian Medical Systems Inc
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Filing: 1971-04-08
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Granted: 1973-08-07
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Expires: 1991-04-08
Abstract
Abstract In an electrostatic copying machine, a transparent cylindrical drum is coated with a layer of transparent conductive material, which serves as a conductive electrode, and which in turn is coated with a photoconductive layer. Optical images to be printed are projected along the axis of the drum to a mirror which reflects them radially onto a thin strip portion of the inside of the photoconductive layer through the transparent layers. Charge is conducted through the illuminated photoconductor to form a charge image on a charge retentive recording web in contact with the outside surface of the drum. The charge image is developed to produce a print of the optical image to be printed.
Inventors
- 👤 F Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:45
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/18; G03G15/22; G03G15/28
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
18 words
The apparatus of claim 1 wherein said endless band of photoconductive material comprises a cylinder of photoconductive material.
Claim 2
Dependent Claim
26 words
The apparatus of claim 2 wherein said optical image projecting means includes means for projecting the optical image into said cylindrical photoconductor from one end thereof.
Claim 3
Dependent Claim
39 words
The apparatus of claim 1 wherein said optical image projecting means includes means for projecting an optical image into said closed path along an optical path having a substantial component of its length axially directed of said closed path.
Claim 4
Dependent Claim
53 words
The apparatus of claim 1 wherein said optical image projecting means includes a mirror disposed within said closed path, said mirror being inclined at an angle relative to the axis of said closed path to reflect the optical image radially of the closed path and onto the inside surface of said photoconductive material.
Claim 5
Dependent Claim
45 words
The apparatus of claim 1 wherein said optical image projecting means includes means for scanning an optical image pattern to be printed at a certain scanning rate, means for synchronizing the peripheral velocity of said circulating band of photoconductive material with the optical scanning rate.
Claim 6
Dependent Claim
59 words
The apparatus of claim 6 wherein said optical image projecting means magnifies the optical image to be projected and as projected onto said photoconductor by a magnification factor of m, and wherein said synchronizing means causes the peripheral velocity of said photoconductive material to be m times the velocity at which the optical image to be projected is scanned.
Claim 7
Dependent Claim
30 words
The apparatus of claim 1 wherein said recording medium comprises a conductive paper web having a dielectric coating thereon, such coating forming the charge retentive surface of said recording medium.
Claim 8
Dependent Claim
39 words
The apparatus of claim 1 wherein said feed means for feeding the recording medium feeds said recording medium over said photoconductor with a velocity in synchronism with the velocity of said photoconductor material as it traverses its closed path.
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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) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |