US3879737A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated electrographic recording and developing stylus assembly
Assignee: 3M Co
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Filing: 1974-04-08
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Granted: 1975-04-22
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Expires: 1994-04-08
Abstract
Abstract An improved electrographic recording stylus for electrographic recording systems includes a magnetic flux concentrating portion and a separate and distinct electrode portion connected to electronic circuitry furnishing voltage potential record pulses to the stylus for electronically charging toner that is in contact therewith.
Inventors
- 👤 George G Lunde
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:10
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/34; G03G15/344; G03G15/348; G03G15/06; G03G15/08; G03G15/09; G03G15/0914; G03G2217/00; G03G2217/0008; G03G2217/0016
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
201 words
In an electrographic recording system that includes a recording electrode electrically connected to one side of a recording medium, a toner developing means having an inner rotating magnet assembly and an outer shell, a plurality of recording styli fixed on the outer shell of said developing means and spaced from the opposite side of said recording medium to define a recording region therebetween that is bridged by toner powder transported on said developing means, and electronic circuitry for providing voltage potential record pulses to said styli, each recording stylus comprising the combination of: a magnetic portion having one end positioned radially outward from said outer shell and formed of a magnetic material such that magnetic flux provided by the magnetic field of said inner magnet assembly is concentrated at the outer end of said stylus to cause a concentration thereat of the toner; and a nonmagnetic electrode portion positioned near said end of said magnetic portion and connected to said electronic circuitry in order that voltage potential record pulses may be applied to said electrode portion to electronically charge the toner powder bridging the recording region and produce deposition of toner on said recording medium in accordance with applied record pulses.
Claim 2
Dependent Claim
201 words
In an electrographic recording system that includes a recording electrode electrically connected to one side of a recording medium, a toner developing means having an inner rotating magnet assembly and an outer shell, a plurality of recording styli fixed on the outer shell of said developing means and spaced from the opposite side of said recording medium to define a recording region therebetween that is bridged by toner powder transported on said developing means, and electronic circuitry for providing voltage potential record pulses to said styli, each recording stylus comprising the combination of: a magnetic portion having one end positioned radially outward from said outer shell and formed of a magnetic material such that magnetic flux provided by the magnetic field of said inner magnet assembly is concentrated at the outer end of said stylus to cause a concentration thereat of the toner; and a nonmagnetic electrode portion positioned near said end of said magnetic portion and connected to said electronic circuitry in order that voltage potential record pulses may be applied to said electrode portion to electronically charge the toner powder bridging the recording region and produce deposition of toner on said recording medium in accordance with applied record pulses.
Claim 3
Dependent Claim
201 words
In an electrographic recording system that includes a recording electrode electrically connected to one side of a recording medium, a toner developing means having an inner rotating magnet assembly and an outer shell, a plurality of recording styli fixed on the outer shell of said developing means and spaced from the opposite side of said recording medium to define a recording region therebetween that is bridged by toner powder transported on said developing means, and electronic circuitry for providing voltage potential record pulses to said styli, each recording stylus comprising the combination of: a magnetic portion having one end positioned radially outward from said outer shell and formed of a magnetic material such that magnetic flux provided by the magnetic field of said inner magnet assembly is concentrated at the outer end of said stylus to cause a concentration thereat of the toner; and a nonmagnetic electrode portion positioned near said end of said magnetic portion and connected to said electronic circuitry in order that voltage potential record pulses may be applied to said electrode portion to electronically charge the toner powder bridging the recording region and produce deposition of toner on said recording medium in accordance with applied record pulses.
Claim 4
Dependent Claim
201 words
In an electrographic recording system that includes a recording electrode electrically connected to one side of a recording medium, a toner developing means having an inner rotating magnet assembly and an outer shell, a plurality of recording styli fixed on the outer shell of said developing means and spaced from the opposite side of said recording medium to define a recording region therebetween that is bridged by toner powder transported on said developing means, and electronic circuitry for providing voltage potential record pulses to said styli, each recording stylus comprising the combination of: a magnetic portion having one end positioned radially outward from said outer shell and formed of a magnetic material such that magnetic flux provided by the magnetic field of said inner magnet assembly is concentrated at the outer end of said stylus to cause a concentration thereat of the toner; and a nonmagnetic electrode portion positioned near said end of said magnetic portion and connected to said electronic circuitry in order that voltage potential record pulses may be applied to said electrode portion to electronically charge the toner powder bridging the recording region and produce deposition of toner on said recording medium in accordance with applied record pulses.
Claim 5
Dependent Claim
45 words
In a recording system as recited in claim 1 wherein the magnetic portion of each of said recording styli is formed from an electrically nonconductive material and said electrode portion of each of said styli overlies and is in physical contact with said magnetic portion.
Claim 6
Dependent Claim
25 words
In a recording system as recited in claim 1 wherein the magnetic portion of each of said styli is electrically insulated from said electrode portion.
Claim 7
Dependent Claim
16 words
In a recording system as recited in claim 3 wherein said magnetic portion is electrically conductive.
Claim 8
Dependent Claim
29 words
In a recording system as recited in claim 1 wherein an electrically insulating layer overlies the end of said magnetic portion and said electrode portion overlies said insulative layer.
Claim 9
Dependent Claim
192 words
In an electrographic recording system that includes a recording electrode electrically contacting one side of a recording medium, a toner developing means having an inner rotating magnet assembly and an outer shell, a plurality of recording styli fixed on the outer shell of said developing means and spaced from the opposite side of said recording medium to define a recording region therebetween that is bridged by toner powder transported on said developing means, and electronic circuitry for providing voltage potential record pulses to the styli, said recording styli comprising the combination of: at least one magnetic portion having an end positioned radially outward from said outer shell such that the magnetic flux provided by the magnetic field of said inner magnet assembly is concentrated at the outer end of said styli; and a plurality of spaced apart nonmagnetic electrode portions positioned near Said end of said magnetic portions and connected to said electronic circuitry in order that voltage potential record pulses may be applied to said electrode portions to electronically charge the toner bridging the recording region to produce deposition of toner on said recording medium in accordance with applied record pulses.
Claim 10
Dependent Claim
192 words
In an electrographic recording system that includes a recording electrode electrically contacting one side of a recording medium, a toner developing means having an inner rotating magnet assembly and an outer shell, a plurality of recording styli fixed on the outer shell of said developing means and spaced from the opposite side of said recording medium to define a recording region therebetween that is bridged by toner powder transported on said developing means, and electronic circuitry for providing voltage potential record pulses to the styli, said recording styli comprising the combination of: at least one magnetic portion having an end positioned radially outward from said outer shell such that the magnetic flux provided by the magnetic field of said inner magnet assembly is concentrated at the outer end of said styli; and a plurality of spaced apart nonmagnetic electrode portions positioned near Said end of said magnetic portions and connected to said electronic circuitry in order that voltage potential record pulses may be applied to said electrode portions to electronically charge the toner bridging the recording region to produce deposition of toner on said recording medium in accordance with applied record pulses.
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) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |