US4448512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light means for exposing and light means for discharging in a electrophotographic printing machine
Assignee: Xerox Corp
•
Filing: 1982-05-19
•
Granted: 1984-05-15
•
Expires: 2002-05-19
Abstract
Abstract An electrophotographic printing machine in which a light image exposing a non-uniform charge pattern formed on a photoconductive member is substantially attenuated to record a latent image thereon. Substantially unattenuated light rays discharge selected portions of the charge pattern. In this manner, fatigue of the photoconductive member is minimized.
Inventors
- 👤 Lloyd F. Bean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:36
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/045
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
111 words
An electrophotographic printing machine, including: a photoconductive member; means for charging said photoconductive member; means, in communication with said photoconductive member, for forming a non-uniform charge pattern on said photoconductive member and optically filtering light rays transmitted thereto; means for exposing the non-uniform charge pattern with a light image to record a latent image on said photoconductive member with the light image being substantially attenuated by said forming and filtering means; and means for transmitting light rays onto selected portions of said photoconductive member to discharge selected regions of the charge pattern with the light rays being of a bandwith selected to be substantially unattenuated by said forming and filtering means.
Claim 2
Dependent Claim
111 words
An electrophotographic printing machine, including: a photoconductive member; means for charging said photoconductive member; means, in communication with said photoconductive member, for forming a non-uniform charge pattern on said photoconductive member and optically filtering light rays transmitted thereto; means for exposing the non-uniform charge pattern with a light image to record a latent image on said photoconductive member with the light image being substantially attenuated by said forming and filtering means; and means for transmitting light rays onto selected portions of said photoconductive member to discharge selected regions of the charge pattern with the light rays being of a bandwith selected to be substantially unattenuated by said forming and filtering means.
Claim 3
Dependent Claim
30 words
A printing machine according to claim 1, further including means for developing the latent image recorded on said photoconductive member with uncharged marking particles to form a particle image thereon.
Claim 4
Dependent Claim
21 words
A printing machine according to claim 2, further including means for transferring the particle image to a sheet of support material.
Claim 5
Dependent Claim
21 words
A printing machine according to claim 3, further including means for fixing the particle image to the sheet of support material.
Claim 6
Dependent Claim
49 words
A printing machine according to claim 4, wherein said forming and filtering means includes a screen of a preselected color positioned adjacent one surface of said photoconductive member, said screen substantially attenuating light rays over a preselected bandwidth with the light rays outside the preselected bandwidth remaining substantially unattenuated.
Claim 7
Dependent Claim
17 words
A printing machine according to claim 5, wherein said screen is positioned interiorly of said photoconductive member.
Claim 8
Dependent Claim
17 words
A printing machine according to claim 5, wherein said screen is positioned exteriorly of said photoconductive member.
Claim 9
Dependent Claim
30 words
A printing machine according to claim 5, wherein said exposing means is positioned to transmit the light image onto the surface of said photoconductive member having said screen adjacent thereto.
Claim 10
Dependent Claim
33 words
A printing machine according to claim 8, wherein said transmitting means includes a light source disposed intermediate said exposing means and said developing means to discharge the inter-image region of said photoconductive member.
Claim 11
Dependent Claim
35 words
A printing machine according to claim 9, wherein said transmitting means includes a second light source spaced from said first mentioned light source and positioned prior to said charging means and after said transferring means.
Claim 12
Dependent Claim
30 words
A printing machine according to claims 9 or 10, wherein said photoconductive member is a drum with said light source being disposed exteriorly thereof and said exposing means interiorly thereof.
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) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |