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US4572647A
Expired / Lapsed
US
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Hybrid development system
Assignee: Xerox Corp
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Filing: 1983-11-23
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Granted: 1986-02-25
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Expires: 2003-11-23
Abstract
Abstract An electrophotographic printing machine in which a latent image is recorded on a photoconductive surface. The latent image is developed with charged, insulating marking particles and magnetic, polar or polarizable marking particles. The charged, insulating marking particles optimize development of low density lines in the latent image with the magnetic, polar or polarizable marking particles optimizing development of halftones in the latent image.
Inventors
- 👤 Lloyd F. Bean
- 👤 Roger L. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:39
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G13/09; G03G13/01; G03G13/013; G03G15/00; G03G15/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
57 words
An electrophotographic printing machine of the type having a photoconductive member, including: means for recording a modulated latent image on the photoconductive member; and means for developing the modulated latent image recorded on the photoconductive member with charged, insulating marking particles and magnetic, polar or polarizable marking particles to form a powder image on the photoconductive member.
Claim 2
Dependent Claim
57 words
An electrophotographic printing machine of the type having a photoconductive member, including: means for recording a modulated latent image on the photoconductive member; and means for developing the modulated latent image recorded on the photoconductive member with charged, insulating marking particles and magnetic, polar or polarizable marking particles to form a powder image on the photoconductive member.
Claim 3
Dependent Claim
31 words
A printing machine according to claim 1, wherein said recording means includes: means for forming an unmodulated latent image on the photoconductive member; and means for modulating the unmodulated latent image.
Claim 4
Dependent Claim
19 words
A printing machine according to claim 2, further including means for charging the powder image on the photoconductive member.
Claim 5
Dependent Claim
57 words
A printing machine according to claim 2, wherein said developing means includes: first means for transporting the charged, insulating marking particles closely adjacent to the modulated latent image recorded on the photoconductive member; and second means for transporting the magnetic, polar or polarizable marking particles closely adjacent to the modulated latent image recorded on the photoconductive member.
Claim 6
Dependent Claim
48 words
A printing machine according to claim 2, wherein said forming means includes: means for charging the surface of the photoconductive member to a substantially uniform level; and means for selectively illuminating the charged portion of the surface of the photoconductive member to record the unmodulated latent image thereon.
Claim 7
Dependent Claim
51 words
A printing machine according to claim 5, wherein said modulating means includes: a light source arranged to transmit light rays onto the unmodulated latent image; and a screen positioned in the path of the light rays being transmitted onto the unmodulated latent image to modulate the light rays being tranmitted thereto.
Claim 8
Independent Claim
50 words
A method of electrophotographic printing, including the steps of: recording a modulated latent image on the photoconductive member; and developing the modulated latent image recorded on the photoconductive member with charged, insulating marking particles and magnetic, polar or polarizable marking particles to form a powder image on the photoconductive member.
Claim 9
Independent Claim
50 words
A method of electrophotographic printing, including the steps of: recording a modulated latent image on the photoconductive member; and developing the modulated latent image recorded on the photoconductive member with charged, insulating marking particles and magnetic, polar or polarizable marking particles to form a powder image on the photoconductive member.
Claim 10
Dependent Claim
32 words
A method of printing according to claim 7, wherein said step of recording includes the steps of: forming an unmodulated latent image on the photoconductive member; and modulating the unmodulated latent image.
Claim 11
Dependent Claim
21 words
A method of printing according to claim 8, further including the step of charging the powder image on the photoconductive member.
Claim 12
Dependent Claim
56 words
A method of printing according to claim 8, wherein said step of developing includes the steps of: transporting the charged, insulating marking particles closely adjacent to the modulated latent image recorded on the photoconductive member; and advancing the magnetic, polar or polarizable marking particles closely adjacent to the modulated latent image recorded on the photoconductive member.
Claim 13
Dependent Claim
49 words
A method of printing according to claim 8, wherein said step of forming includes the steps of: charging the surface of the photoconductive member to a substantially uniform level; and illuminating selectively the charged portion of the surface of the photoconductive member to record the unmodulated latent image thereon.
Claim 14
Dependent Claim
51 words
A method of printing according to claim 11, wherein said step of modulating includes the steps of: transmitting light rays onto the unmodulated latent image; and positioning a screen in the path of the light rays being transmitted onto the unmodulated latent image to modulate the light rays being transmitted thereto.
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) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |