US3867673A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for forming a positive electrostatic image
Assignee: Markem Imaje Corp
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Filing: 1972-08-17
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Granted: 1975-02-18
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Expires: 1992-08-17
Abstract
Abstract A machine for making a copy on a medium such as paper of a visual image. Particles of toner material are accelerated toward the paper through an apertured screen. Formed on the screen is a pattern of electrostatic charge regions that corresponds to the image so that the arrangement of the toner particles impinging on the paper corresponds to the image. A composite apertured screen composed of two conductive layers separated by an insulative layer and having an insulative layer on one outer surface. Means for establishing oppositely polarized fields across the inner insulative layer and across the outer insulative layer. One of the fields is selectively discharged to control the passage of toner particles through the apertures in the screen.
Inventors
- 👤 Hewitt D Crane
- 👤 George J Eilers
- 👤 Gerald L Pressman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:26
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/34; G03G15/344; G03G15/346
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
76 words
Apparatus for controlling the flow of electrostatically charged particles along a path comprising, in combination, means for establishing a first electric field across a first insulator layer so polarized as to prevent movement of particles along the path; and means for establishing a second electrical field across a second insulator layer in spaced superposition to said first insulator, said second electrical field selectively counteracting said first electric field in accordance with an image to be reproduced.
Claim 2
Dependent Claim
76 words
Apparatus for controlling the flow of electrostatically charged particles along a path comprising, in combination, means for establishing a first electric field across a first insulator layer so polarized as to prevent movement of particles along the path; and means for establishing a second electrical field across a second insulator layer in spaced superposition to said first insulator, said second electrical field selectively counteracting said first electric field in accordance with an image to be reproduced.
Claim 3
Dependent Claim
33 words
The apparatus of claim 1 wherein the means for selectively counteracting the means for said first electric field is light sensitive and the means for establishing a first electric field is light insensitive.
Claim 4
Dependent Claim
44 words
The invention of claim 1 wherein said counteracting means comprises means for establishing a second electric field having a polarity opposite from and a magnitude greater than said first field so as to counteract said first field, and means selectively discharging said second field.
Claim 5
Dependent Claim
30 words
The invention of claim 3 wherein the means for establishing one of said fields is light sensitive and the means for establishing the other of said fields is light insensitive.
Claim 6
Dependent Claim
19 words
The invention of claim 4 wherein the means for establishing said fields are arranged to space said fields apart.
Claim 7
Dependent Claim
41 words
The invention of claim 3 including a body having an aperture that defines a wall circumscribing the particle path, said first and second field establishing means residing within said body and being adapted to establish respective said fields within said aperture.
Claim 8
Dependent Claim
49 words
The invention of claim 6 wherein said body comprises first and second conductive layers, and an insulative layer interposed between said conductive layers, said layers terminating in said aperture wall so that a potential difference can be maintained between said conductive layers to constitute said first fIeld establishing means.
Claim 9
Dependent Claim
48 words
The invention of claim 7 in combination with a photoconductive layer superposed on the surface of said second conductive layer opposite said insulative layer, said photoconductive layer terminating in said aperture wall and constituting in conjunction with said first and second conductive layer said second field establishing means.
Claim 10
Dependent Claim
73 words
A multilayered apertured screen for controlling the flow of a stream of charged particles directed through the screen comprising: a first screen layer of conductive material; a second screen layer of insulative material adjacent said first layer; a third screen layer of conductive material formed adjacent said insulative layer and electrically isolated from said first conductive layer; and a fourth layer of photoconductive material coated on the outside of said third conductive layer.
Claim 11
Dependent Claim
73 words
A multilayered apertured screen for controlling the flow of a stream of charged particles directed through the screen comprising: a first screen layer of conductive material; a second screen layer of insulative material adjacent said first layer; a third screen layer of conductive material formed adjacent said insulative layer and electrically isolated from said first conductive layer; and a fourth layer of photoconductive material coated on the outside of said third conductive layer.
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) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |