Patent US4129072A successfully refreshed from Google Patents.
US4129072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic printing
Assignee: Canon Inc
•
Filing: 1977-01-21
•
Granted: 1978-12-12
•
Expires: 1997-01-21
Abstract
Abstract The disclosure describes an improved electrostatic printing in which cleaning step and developing step are united together as single combined step. It is possible to carry out charging step and transferring step with same single means. The electrostatic printing is adaptable for making a large number of prints at a high speed. The developing agent can be recovered and reused very efficiently.
Inventors
- 👤 Motoharu Fujii
- 👤 Takao Muramatsu
- 👤 Noboru Koumura
- 👤 Susumu Sugiura
- 👤 Nobuhiro Takekawa
- 👤 Syusei Tsukada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:20
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; Y; Y10; Y10S; Y10S101/00; Y10S101/37
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
137 words
An electrostatic printing apparatus which comprises: an electrostatic printing image carrier comprising essentially a dielectric medium having an electric resistance sufficient to hold a static charge and a layer composed essentially of silver image carried by the medium; charging means for charging the dielectric medium with a static charge corresponding to the same; developing means for developing with developing material the latent image formed on said image carrier corresponding to the static charge; cleaning means for cleaning the surface of the image carrier after charging and before developing, said cleaning means being provided within said developing means so that the developing material removed from the image carrier by said cleaning means is redeposited in said developing means; and transferring means for transferring the image developed on the dielectric medium from said image carrier to a transfer material.
Claim 2
Dependent Claim
137 words
An electrostatic printing apparatus which comprises: an electrostatic printing image carrier comprising essentially a dielectric medium having an electric resistance sufficient to hold a static charge and a layer composed essentially of silver image carried by the medium; charging means for charging the dielectric medium with a static charge corresponding to the same; developing means for developing with developing material the latent image formed on said image carrier corresponding to the static charge; cleaning means for cleaning the surface of the image carrier after charging and before developing, said cleaning means being provided within said developing means so that the developing material removed from the image carrier by said cleaning means is redeposited in said developing means; and transferring means for transferring the image developed on the dielectric medium from said image carrier to a transfer material.
Claim 3
Dependent Claim
31 words
An electrostatic printing apparatus as claimed in claim 1 wherein the layer composed essentially of silver image is a layer of silver image formed from free silver formative silver salt compound.
Claim 4
Dependent Claim
20 words
An electrostatic printing apparatus as claimed in claim 1, wherein said charging means and said transferring means are operated simultaneously.
References Cited (Backward Citations)
US2756676A
Cited
US3033765A
Cited
US3132963A
Cited
US3368894A
Cited
US3759220A
Cited
US3818492A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-11 | 1982-06-12 | 1982-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-11 | 1986-06-12 | 1986-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-11 | 1990-06-12 | 1990-12-12 | $7700.00 | Window Closed / Lapsed |