Patent US3942979A successfully refreshed from Google Patents.
US3942979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Imaging system
Assignee: Xerox Corp
•
Filing: 1974-05-30
•
Granted: 1976-03-09
•
Expires: 1994-05-30
Abstract
Abstract An electrostatographic imaging process comprising the steps of providing an electrostatographic imaging member having a recording surface, forming an electrostatic latent image on said recording surface, and contacting said electrostatic latent image with a developer mixture comprising classified toner materials electrostatically clinging to the surface of classified high surface area carrier materials, said classified toner materials having a particle size number distribution with a fine index ratio of less than about 2.50, a particle size volume distribution with a coarse index ratio less than about 1.50, and a particle size distribution wherein less than about 30.0 percent by number of the toner particles have an average particle size diameter of less than about 5 microns, about 25% of the particles have a diameter between about 8 microns and about 12 microns, and less than about 5% by number of the toner particles have an average particle diameter greater than about 20 microns, said classified high surface area carrier materials having a specific surface area of at least about 150 cm 2 /gram, whereby at least a portion of said finely-divided toner particles are attracted to and deposited on said recording surface in conformance with said electrostatic latent image.
Inventors
- 👤 Lewis O. Jones
- 👤 Robert Mermelstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:35
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0819; G03G9/10
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
212 words
An electrostatographic imaging process comprising the steps of providing an electrostatographic imaging member having a recording surface, forming an electrostatic latent image on said recording surface, and contacting said electrostatic latent image with a developer mixture comprising classified toner materials electrostatically clinging to the surface of classified high surface area carrier materials, said classified toner materials having a particle size number distribution with a fine index ratio of less than about 2.50, a particle size volume distribution with a coarse index ratio less than about 1.50, and a particle size distribution wherein less than about 30.0 percent by number of the toner particles have an average particle size diameter of less than about 5 microns, about 25% of the particles have a diameter between about 8 microns and about 12 microns, and less than about 5% by number of the toner particles have an average particle diameter greater than about 20 microns, said classified high surface area carrier materials having a specific surface area of at least about 150 cm 2 /gram and a particle size volume distribution geometric standard deviation of less than about 1.3, whereby at least a portion of said finely-divided toner particles are attracted to and deposited on said recording surface in conformance with said electrostatic latent image.
Claim 2
Dependent Claim
212 words
An electrostatographic imaging process comprising the steps of providing an electrostatographic imaging member having a recording surface, forming an electrostatic latent image on said recording surface, and contacting said electrostatic latent image with a developer mixture comprising classified toner materials electrostatically clinging to the surface of classified high surface area carrier materials, said classified toner materials having a particle size number distribution with a fine index ratio of less than about 2.50, a particle size volume distribution with a coarse index ratio less than about 1.50, and a particle size distribution wherein less than about 30.0 percent by number of the toner particles have an average particle size diameter of less than about 5 microns, about 25% of the particles have a diameter between about 8 microns and about 12 microns, and less than about 5% by number of the toner particles have an average particle diameter greater than about 20 microns, said classified high surface area carrier materials having a specific surface area of at least about 150 cm 2 /gram and a particle size volume distribution geometric standard deviation of less than about 1.3, whereby at least a portion of said finely-divided toner particles are attracted to and deposited on said recording surface in conformance with said electrostatic latent image.
Claim 3
Dependent Claim
25 words
An electrostatographic imaging process according to claim 1 wherein said carrier materials have a specific surfce area of at least about 165 cm 2 /gram.
Claim 4
Dependent Claim
25 words
An electrostatographic imaging process according to claim 1 wherein said carrier materials have a specific surface area of at least about 175 cm 2 /gram.
Claim 5
Dependent Claim
25 words
An electrostatographic imaging process according to claim 1 wherein said classified toner materials have a particle size number distribution fine index of less than 2.00.
Claim 6
Dependent Claim
26 words
An electrostatographic imaging process according to claim 1 wherein said classified toner materials have a particle size number distribution fine index of less than about 1.45.
Claim 7
Dependent Claim
26 words
An electrostatographic imaging process according to claim 1 wherein said classified toner materials have a particle size volume distribution coarse index of less than about 1.45.
Claim 8
Dependent Claim
26 words
An electrostatographic imaging process according to claim 1 wherein said classified toner materials have a particle size volume distribution coarse index of less than about 1.35.
Claim 9
Dependent Claim
83 words
An electrostatographic imaging process according to claim 1 wherein said classified toner materials have a particle size distribution wherein less than about 20% by number of the toner particles have an average particle diameter of less than about 5 microns, about 45% by number of the toner particles have an average particle diameter of between about 8 microns and about 12 microns, and less than about 5% by number of the toner particles have an average particle diameter greater than about 20 microns.
Claim 10
Dependent Claim
83 words
An electrostatographic imaging process according to claim 1 wherein said classified toner materials have a particle size distribution wherein less than about 10% by number of the toner particles have an average particle diameter of less than about 5 microns, about 60% by number of the toner particles have an average particle diameter of between about 8 microns and about 12 microns, and less than about 5% by number of the toner particles have an average particle diameter greater than about 20 microns.
Claim 11
Dependent Claim
39 words
An electrostatographic imagingn process according to claim 1 wherein said classified carrier materials have a particle size volume distribution geometric standard deviation of less than about 1.2 and a volume average particle diameter of less than about 90 microns.
Claim 12
Dependent Claim
37 words
An electrostatographic imaging process according to claim 1 wherein said classified carrier materials have a volume distribution geometric standard deviation of less than about 1.15 and a volume average particle diameter of less than about 85 microns.
Claim 13
Dependent Claim
23 words
An electrostatographic imaging process according to claim 1 wherein said carrier materials are overcoated with a thin continuous film of a coating material.
Claim 14
Dependent Claim
30 words
An electrostatographic imaging process according to claim 12 wherein said coating material comprises from about 0.1% to about 10.0% by weight based on the weight of the coated carrier particles.
Claim 15
Dependent Claim
34 words
An electrostatographic imaging process according to claim 1 wherein said carrier material comprises nickel-zinc ferrite coated with a thin continuous film of a coating composition comprising styrene, a methacrylate ester, and an organosilicon compound.
Claim 16
Dependent Claim
48 words
An electrostatographic imaging process according to claim 1 wherein said toner material comprises a mixture of about 90 parts by weight of a copolymer of about 58.0% by weight of styrene, about 42.0% by weight of n-butylmethacrylate, and about 10 parts by weight of a furnace carbon black.
References Cited (Backward Citations)
US3080251A
Cited
US3650797A
Cited
US3533835A
Cited
US3586654A
Cited
US3674736A
Cited
US3745118A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |