US4142981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toner combination for carrierless development
Assignee: Xerox Corp
•
Filing: 1977-07-05
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Granted: 1979-03-06
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Expires: 1997-07-05
Abstract
Abstract A toner and electrostatic development process involving electrostatic development without carrier is disclosed. The toner of the invention is effectively transferred from photoreceptors to plain paper after development. The toner is formed of a combination of an insulating toner and conductive toner that are not triboelectrically active with respect to each other.
Inventors
- 👤 Lloyd F. Bean
- 👤 Roger L. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:26
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/09; G03G9/0902; G03G9/0904; B; B82; B82Y; B82Y15/00; G03G9/0821; G03G9/0823
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
64 words
A combination electrophotographic toner composition comprising electrically insulating toner particles and electrically conductive toner particles that are not triboelectrically active with each other, said conductive toner particles comprising resin and magnetic particles, and having a resistivity of between about 10 4 and 10 10 ohm-cm, and said insulating toner particles comprising resin and carbon black and having a resistivity greater than 10 11 ohm-cm.
Claim 2
Dependent Claim
64 words
A combination electrophotographic toner composition comprising electrically insulating toner particles and electrically conductive toner particles that are not triboelectrically active with each other, said conductive toner particles comprising resin and magnetic particles, and having a resistivity of between about 10 4 and 10 10 ohm-cm, and said insulating toner particles comprising resin and carbon black and having a resistivity greater than 10 11 ohm-cm.
Claim 3
Dependent Claim
24 words
The toner of claim 1 wherein said insulating toner particles comprise about 20 to about 70 percent by weight of said combination toner composition.
Claim 4
Dependent Claim
25 words
The toner of claim 2 wherein said magnetic particles are magnetite and comprise between about 40 and about 80 percent by weight of said toner.
Claim 5
Dependent Claim
22 words
The toner of claim 1 wherein said conductive toner comprises between about 40 and about 70 weight percent of said combination toner.
Claim 6
Dependent Claim
20 words
The toner of claim 1 wherein said combination toner has particle size range between about 5 and about 30 microns.
Claim 7
Dependent Claim
22 words
The toner of claim 1 wherein said conductive and said insulating toners have similar triboelectric properties when compared with a common carrier.
Claim 8
Dependent Claim
11 words
The toner of claim 2 wherein said magnetic particles comprise magnetite.
Claim 9
Dependent Claim
22 words
The toner of claim 1 wherein said insulating and said conductive toner have a resistivity difference of greater than 10 4 ohm-cm.
Claim 10
Dependent Claim
22 words
The toner of claim 1 wherein said insulating and said conductive toner have a resistivity difference of greater than 10 6 ohm-cm.
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) | 1982-03-05 | 1982-09-04 | 1983-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-05 | 1986-09-04 | 1987-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-05 | 1990-09-04 | 1991-03-06 | $7700.00 | Window Closed / Lapsed |