Patent US3909258A successfully refreshed from Google Patents.
US3909258A
Expired / Lapsed
US
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Electrographic development process
Assignee: 3M Co
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Filing: 1974-01-02
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Granted: 1975-09-30
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Expires: 1994-01-02
Abstract
Abstract An electrographic process involving the development of electrical potential patterns on a recording medium surface, for example electrostatic charge patterns on a photoconductive element, with electronically conductive, magnetically attractable toner material utilizing electrical forces generated by the electrical potential in the image areas of the recording medium to overcome a threshold magnetic counterforce exerted on the toner material by means of an electrical potential biased toner material applicator. The electrical potential pattern may be supplemented by a corresponding electronic conductivity pattern on the recording medium surface.
Inventors
- 👤 Arthur R Kotz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:25
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0914; B; B82; B82Y; B82Y15/00; G03G13/00; G03G13/06; G03G13/08; G03G13/09
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
67 words
PROVIDING ONE SURFACE OF A LAYER OF MATERIAL WITH AREAS THEREOF HAVING AN ELECTRICAL POTENTIAL WITH RESPECT TO THE OTHER SURFACE OF SAID LAYER IN A RANGE DEFINING IMAGE AREAS AND OTHER AREAS THEREOF HAVING AN ELECTRICAL POTENTIAL WITH RESPECT TO THE OTHER SURFACE OF SAID LAYER IN A RANGE DEFINING NON-IMAGE AREAS, SAID AREAS DEFINING AN ELECTRICAL POTENTIAL PATTERN CORRESPONDING TO THE PATTERN TO BE PRODUCED,
Claim 2
Dependent Claim
67 words
PROVIDING ONE SURFACE OF A LAYER OF MATERIAL WITH AREAS THEREOF HAVING AN ELECTRICAL POTENTIAL WITH RESPECT TO THE OTHER SURFACE OF SAID LAYER IN A RANGE DEFINING IMAGE AREAS AND OTHER AREAS THEREOF HAVING AN ELECTRICAL POTENTIAL WITH RESPECT TO THE OTHER SURFACE OF SAID LAYER IN A RANGE DEFINING NON-IMAGE AREAS, SAID AREAS DEFINING AN ELECTRICAL POTENTIAL PATTERN CORRESPONDING TO THE PATTERN TO BE PRODUCED,
Claim 3
Dependent Claim
19 words
A PROCESS FOR APPLYING TONER MATERIAL SELECTIVELY TO PREDETERMINED AREAS OF ONE SURFACE OF A LAYER OF MATERIAL COMPRISING:
Claim 4
Dependent Claim
19 words
A PROCESS FOR APPLYING TONER MATERIAL SELECTIVELY TO PREDETERMINED AREAS OF ONE SURFACE OF A LAYER OF MATERIAL COMPRISING:
Claim 5
Dependent Claim
47 words
PROVIDING A CYLINDRICAL ELECTRICALLY CONDUCTIVE SUPPORT ELECTRICALLY CONNECTED TO SAID OTHER SURFACE WITH SAID SUPPORT PRESENTING A UNIFORM QUANTITY OF ONE-COMPONENT MAGNETICALLY ATTRACTABLE, ELECTRONICALLY CONDUCTIVE TONER MATERIAL BOUND TO SAID SUPPORT BY A MAGNETIC FORCE OF ATTRACTION WHICH IS UNIFORM ALONG AXIAL LENGTH OF SAID CYLINDRICAL SUPPORT,
Claim 6
Dependent Claim
47 words
PROVIDING A CYLINDRICAL ELECTRICALLY CONDUCTIVE SUPPORT ELECTRICALLY CONNECTED TO SAID OTHER SURFACE WITH SAID SUPPORT PRESENTING A UNIFORM QUANTITY OF ONE-COMPONENT MAGNETICALLY ATTRACTABLE, ELECTRONICALLY CONDUCTIVE TONER MATERIAL BOUND TO SAID SUPPORT BY A MAGNETIC FORCE OF ATTRACTION WHICH IS UNIFORM ALONG AXIAL LENGTH OF SAID CYLINDRICAL SUPPORT,
Claim 7
Dependent Claim
21 words
The process of claim 1 wherein said image and non-image areas are electrically insulating while said electronically conductive path is present.
Claim 8
Dependent Claim
48 words
providing a cylindrical electrically conductive support electrically connected to said other surface with said support presenting a uniform quantity of one-component magnetically attractable, electronically conductive toner material bound to said support by a magnetic force of attraction which is uniform along the axial length of said cylindrical support,
Claim 9
Dependent Claim
48 words
providing a cylindrical electrically conductive support electrically connected to said other surface with said support presenting a uniform quantity of one-component magnetically attractable, electronically conductive toner material bound to said support by a magnetic force of attraction which is uniform along the axial length of said cylindrical support,
Claim 10
Dependent Claim
59 words
IS MAINTAINED FOR A PERIOD SUFFICIENT TO ALLOW SAID TRANSIENT ELECTRICAL TRANSFER FORCE WHICH IS GREATER THAN AND OPPOSED TO SAID MAGNETIC FORCE OF ATTRACTION IN SAID IMAGE AREAS TO BE INDUCED, AND B. IS DICONTINUED WHILE SUCH LEVEL OF SAID TRANSIENT ELECTRICAL FORCE EXISTS WHEREBY SAID TONER MATERIAL IS SELECTIVELY DEPOSITED ON SAID IMAGE AREAS OF SAID SURFACE.
Claim 11
Dependent Claim
59 words
IS MAINTAINED FOR A PERIOD SUFFICIENT TO ALLOW SAID TRANSIENT ELECTRICAL TRANSFER FORCE WHICH IS GREATER THAN AND OPPOSED TO SAID MAGNETIC FORCE OF ATTRACTION IN SAID IMAGE AREAS TO BE INDUCED, AND B. IS DICONTINUED WHILE SUCH LEVEL OF SAID TRANSIENT ELECTRICAL FORCE EXISTS WHEREBY SAID TONER MATERIAL IS SELECTIVELY DEPOSITED ON SAID IMAGE AREAS OF SAID SURFACE.
Claim 12
Dependent Claim
50 words
ARRANGING SAID ELECTRICALLY CONDUCTIVE SUPPORT ADJACENT TO AND IN SPACED RELATION TO SAID ONE SURFACE AT A UNIFORM DISTANCE THEREFROM OF AT LEAST TWICE THE MAJOR DIMENSION OF THE LARGEST OF SAID TONER MATERIAL WHEREBY SAID TONER MATERIAL PROVIDES A ELECTRONICALLY CONDUCTIVE PATH BETWEEN SAID SUPPORT AND SAID ONE SURFACE,
Claim 13
Dependent Claim
50 words
ARRANGING SAID ELECTRICALLY CONDUCTIVE SUPPORT ADJACENT TO AND IN SPACED RELATION TO SAID ONE SURFACE AT A UNIFORM DISTANCE THEREFROM OF AT LEAST TWICE THE MAJOR DIMENSION OF THE LARGEST OF SAID TONER MATERIAL WHEREBY SAID TONER MATERIAL PROVIDES A ELECTRONICALLY CONDUCTIVE PATH BETWEEN SAID SUPPORT AND SAID ONE SURFACE,
Claim 14
Dependent Claim
50 words
arranging said electrically conductive support adjacent to and in spaced relation to said one surface at a uniform distance therefrom of at least twice the major dimension of the largest of said toner material whereby said toner material provides a electronically conductive path between said support and said one surface,
Claim 15
Dependent Claim
50 words
arranging said electrically conductive support adjacent to and in spaced relation to said one surface at a uniform distance therefrom of at least twice the major dimension of the largest of said toner material whereby said toner material provides a electronically conductive path between said support and said one surface,
Claim 16
Dependent Claim
21 words
The process of claim 1 wherein at least said image areas are electrically insulating while said electronically conductive path is present.
Claim 17
Dependent Claim
26 words
The process of claim 1 wherein said image areas are electrically insulating and said non-image areas are electrically conductive while said electronically conductive path is present.
Claim 18
Dependent Claim
87 words
establishing said support at an electrical potential of a magnitude and polarity such that the difference in electrical potential between said support and said one surface, when the toner is presented in accordance with steps 2 and 3, induces a transient electrical transfer force on said toner material in said electronically conductive path, which for a period of time is greater than and opposed to said magnetic force of attraction in said image areas and less than said magnetic force of attraction in said non-image areas, and
Claim 19
Dependent Claim
87 words
establishing said support at an electrical potential of a magnitude and polarity such that the difference in electrical potential between said support and said one surface, when the toner is presented in accordance with steps 2 and 3, induces a transient electrical transfer force on said toner material in said electronically conductive path, which for a period of time is greater than and opposed to said magnetic force of attraction in said image areas and less than said magnetic force of attraction in said non-image areas, and
Claim 20
Dependent Claim
87 words
ESTABLISHING SAID SUPPORT AT AN ELECTRICAL POTENTIAL OF A MAGNITUDE AND POLARITY SUCH THAT THE DIFFERENCE IN ELECTRICAL POTENTIAL BETWEEN SAID SUPPORT AND SAID ONE SURFACE, WHEN THE TONER IS PRESENTED IN ACCORDANCE WITH STEPS 2 AND 3, INDUCES A TRANSIENT ELECTRICAL TRANSFER FORCE ON SAID TONER MATERIAL IN SAID ELECTRONICALLY CONDUCTIVE PATH, WHICH FOR A PERIOD OF TIME IS GREATER THAN AND OPPOSED TO SAID MAGNETIC FORCE OF ATTRACTION IN SAID IMAGE AREAS AND LESS THAN SAID MAGNETIC FORCE OF ATTRACTION IN SAID NONIMAGE AREAS, AND
Claim 21
Dependent Claim
87 words
ESTABLISHING SAID SUPPORT AT AN ELECTRICAL POTENTIAL OF A MAGNITUDE AND POLARITY SUCH THAT THE DIFFERENCE IN ELECTRICAL POTENTIAL BETWEEN SAID SUPPORT AND SAID ONE SURFACE, WHEN THE TONER IS PRESENTED IN ACCORDANCE WITH STEPS 2 AND 3, INDUCES A TRANSIENT ELECTRICAL TRANSFER FORCE ON SAID TONER MATERIAL IN SAID ELECTRONICALLY CONDUCTIVE PATH, WHICH FOR A PERIOD OF TIME IS GREATER THAN AND OPPOSED TO SAID MAGNETIC FORCE OF ATTRACTION IN SAID IMAGE AREAS AND LESS THAN SAID MAGNETIC FORCE OF ATTRACTION IN SAID NONIMAGE AREAS, AND
Claim 22
Dependent Claim
44 words
PROGRESSIVELY PRESENTING SAID LAYER TO SAID TONER BY PROVIDING UNDIRECTIONAL RELATIVE MOVEMENT BETWEEN SAID LAYER AND SAID SUPPORT WITH AXIS OF SAID SUPPORT NORMAL TO THE DIRECTION OF THE RELATIVE MOVEMENT, SAID RELATIVE MOVEMENT BEING AT A RATE SUCH THAT SAID ELECTRONICALLY CONDUCTIVE PATH
Claim 23
Dependent Claim
44 words
PROGRESSIVELY PRESENTING SAID LAYER TO SAID TONER BY PROVIDING UNDIRECTIONAL RELATIVE MOVEMENT BETWEEN SAID LAYER AND SAID SUPPORT WITH AXIS OF SAID SUPPORT NORMAL TO THE DIRECTION OF THE RELATIVE MOVEMENT, SAID RELATIVE MOVEMENT BEING AT A RATE SUCH THAT SAID ELECTRONICALLY CONDUCTIVE PATH
Claim 24
Dependent Claim
105 words
progressively presenting said layer to said toner by providing unidirectional relative movement between said layer and said support with the axis of said support normal to the direction of the relative movement, said relative movement being at a rate such that said electronically conductive path a. is maintained for a period sufficient to allow said transient electrical transfer force which is greater than and opposed to said magnetic force of attraction in said image areas to be induced, and b. is discontinued while such level of said transient electrical force exists whereby said toner material is selectively deposited on said image areas of said surface.
Claim 25
Dependent Claim
105 words
progressively presenting said layer to said toner by providing unidirectional relative movement between said layer and said support with the axis of said support normal to the direction of the relative movement, said relative movement being at a rate such that said electronically conductive path a. is maintained for a period sufficient to allow said transient electrical transfer force which is greater than and opposed to said magnetic force of attraction in said image areas to be induced, and b. is discontinued while such level of said transient electrical force exists whereby said toner material is selectively deposited on said image areas of said surface.
Claim 26
Dependent Claim
45 words
The process of claim 1 wherein there is a conductivity pattern corresponding to said electrical potential pattern while said electronically conductive path is present, said conductivity pattern being defined by relatively conductive areas in the non-image areas and relatively insulating areas in the image areas.
Claim 27
Dependent Claim
15 words
The process of claim 1 wherein said electrical potential pattern is provided by electrostatic charges.
Claim 28
Dependent Claim
18 words
The process of claim 1 wherein said one surface comprises photoconductive zinc oxide disposed in an insulating binder.
Claim 29
Dependent Claim
12 words
THe process of claim 1 wherein said one surface comprises photoconductive selenium.
Claim 30
Dependent Claim
17 words
The process of claim 1 wherein said non-image areas are at an electrical potential of about ground.
Claim 31
Dependent Claim
22 words
The process of claim 1 wherein the difference in potential between image and non-image areas is at least 20 volts in magnitude.
Claim 32
Dependent Claim
17 words
The process of claim 1 wherein said one surface comprises a dielectric layer overlying a photoconductive layer..
Claim 33
Dependent Claim
26 words
The process of claim 1 wherein said electrical potential pattern is provided in accordance with an imagewise pattern of differing dielectric constant at said one surface.
Claim 34
Dependent Claim
17 words
The process of claim 1 wherein said magnetic force of attraction is at least 10 5 dynes.
Claim 35
Dependent Claim
18 words
The process of claim 1 wherein said non-image areas and said support are at about equal electrical potential.
Claim 36
Dependent Claim
17 words
The process of claim 1 wherein said non-image areas and said support are at about ground potential.
Claim 37
Dependent Claim
31 words
The process of claim 1 wherein said one surface comprises photoconductive zinc oxide disposed in an insulating binder and said non-image areas and said support are at about equal electrical potential.
Claim 38
Dependent Claim
15 words
The process of claim 1 further comprising fixing said toner material to said one surface.
Claim 39
Dependent Claim
16 words
The process of claim 1 further comprising imagewise transferring said toner material to a second surface.
Claim 40
Dependent Claim
25 words
The process of claim 1 further comprising imagewise transferring said toner material to a second surface and fixing said toner material on said second surface.
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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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |