US4465749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic charge differential amplification (CDA) in imaging process
Assignee: NexPress Solutions LLC
•
Filing: 1983-06-20
•
Granted: 1984-08-14
•
Expires: 2003-06-20
Abstract
Abstract A method for amplifying an electrostatic, charge-differential pattern is disclosed. The method comprises (a) imagewise forming a first toner deposit by developing a first electrostatic pattern having a first charge differential per unit area whose maximum value is no greater than a preselected level, (b) in an image-amplification element comprising a charge-holding surface layer overlying a field-supporting electrode, forming a current-carrying path between the toner deposit and the field-supporting electrode, (c) under conditions in which nontoned regions are not photoexcited, overall charging the image-amplification element with sufficient charge to form an enhanced electrostatic charge pattern having a second charge differential per unit area whose maximum value is greater than the preselected value in step (a), and (d) developing the enhanced charge pattern into a second toner deposit. By this process, high-maximum-density, continuous-tone images can be produced wherein the maximum density of such images is obtained by amplification of initial charge differentials whose maximum value is, for example, 30 nanocoulombs/cm 2 or lower. In addition, images can be produced with low contrast, i.e., obtained over a wide exposure range.
Inventors
- 👤 John W. May
- 👤 Yee S. Ng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:47
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
127 words
A method of amplifying an electrostatic charge differential pattern comprising: (a) imagewise forming a first toner deposit by developing a first electrostatic charge pattern having a first charge differential per unit area whose maximum value is no greater than a preselected level, (b) in an image-amplification element comprising a charge-holding surface layer overlying a field-supporting electrode, forming a current-carrying path between said first toner deposit and said field-supporting electrode, (c) under conditions in which nontoned regions of said charge-holding layer are not photoexcited, overall charging said image-amplification element with sufficient charge to form an enhanced electrostatic charge pattern having a second charge differential per unit area whose maximum value is greater than said preselected value, and (d) developing said second charge pattern into a second toner deposit.
Claim 2
Independent Claim
127 words
A method of amplifying an electrostatic charge differential pattern comprising: (a) imagewise forming a first toner deposit by developing a first electrostatic charge pattern having a first charge differential per unit area whose maximum value is no greater than a preselected level, (b) in an image-amplification element comprising a charge-holding surface layer overlying a field-supporting electrode, forming a current-carrying path between said first toner deposit and said field-supporting electrode, (c) under conditions in which nontoned regions of said charge-holding layer are not photoexcited, overall charging said image-amplification element with sufficient charge to form an enhanced electrostatic charge pattern having a second charge differential per unit area whose maximum value is greater than said preselected value, and (d) developing said second charge pattern into a second toner deposit.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said preselected charge differential per unit area is 30 nanocoulombs/cm 2 .
Claim 4
Dependent Claim
24 words
The method of claim 2 wherein the maximum value of said second charge differential per unit area is at least 60 nanocoulombs/cm 2 .
Claim 5
Dependent Claim
48 words
The method of claim 2 wherein the maximum value of said first charge differential per unit area is from about 5 to about 15 nanocoulombs/cm 2 and the maximum value of said second charge differential per unit area is from about 100 to about 150 nanocoulombs/cm 2 .
Claim 6
Independent Claim
131 words
A method of amplifying an electrostatic charge differential pattern comprising: (a) in an image-amplification element comprising a charge-holding surface layer overlying a field-supporting electrode, imagewise forming a first toner deposit by developing a first electrostatic charge pattern having a first charge differential per unit area whose maximum value is no greater than a preselected level, (b) forming in said image-amplification element a current-carrying path between said first toner deposit and said field-supporting electrode, (c) under conditions in which nontoned regions of said charge-holding layer are not photoexcited, overall charging said image-amplification element with sufficient charge to form an enhanced electrostatic charge pattern having a second charge differential per unit area whose maximum value is greater than said preselected value, and (d) developing said second charge pattern into a second toner deposit.
Claim 7
Independent Claim
131 words
A method of amplifying an electrostatic charge differential pattern comprising: (a) in an image-amplification element comprising a charge-holding surface layer overlying a field-supporting electrode, imagewise forming a first toner deposit by developing a first electrostatic charge pattern having a first charge differential per unit area whose maximum value is no greater than a preselected level, (b) forming in said image-amplification element a current-carrying path between said first toner deposit and said field-supporting electrode, (c) under conditions in which nontoned regions of said charge-holding layer are not photoexcited, overall charging said image-amplification element with sufficient charge to form an enhanced electrostatic charge pattern having a second charge differential per unit area whose maximum value is greater than said preselected value, and (d) developing said second charge pattern into a second toner deposit.
Claim 8
Dependent Claim
30 words
The method of claim 5 wherein said charge-holding layer of said image-amplification element is photoconductive and said first electrostatic charge pattern is electrophotographically formed and developed on said charge-holding layer.
Claim 9
Dependent Claim
18 words
The method of claim 6 wherein said first toner deposit comprises a pigment dispersed in a polymeric matrix.
Claim 10
Dependent Claim
12 words
The method of claim 7 wherein said pigment is a conductive pigment.
Claim 11
Dependent Claim
11 words
The method of claim 7 wherein said pigment is carbon black.
Claim 12
Independent Claim
24 words
The method of claims 6, 8 or 9 wherein said current-carrying path is formed by heat-fixing said first toner deposit to said charge-holding layer.
Claim 13
Dependent Claim
18 words
The method of claim 5 wherein said preselected charge differential per unit area is 30 nanocoulombs/cm 2 .
Claim 14
Dependent Claim
24 words
The method of claim 11 wherein the maximum value of said second charge differential per unit area is at least 60 nanocoulombs/cm 2 .
Claim 15
Dependent Claim
48 words
The method of claim 11 wherein the maximum value of said first charge differential per unit area is from about 5 to about 10 nanocoulombs/cm 2 and the maximum value of said second charge differential per unit area is from about 100 to about 150 nanocoulombs/cm 2 .
References Cited (Backward Citations)
US2756676A
Cited
US3888664A
Cited
US3918971A
Cited
US4063946A
Cited
US3981727A
Cited
US4175958A
Cited
US4256820A
Cited
US4278884A
Cited
JPS5746262A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-14 | 1988-02-13 | 1988-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-14 | 1992-02-13 | 1992-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-14 | 1996-02-13 | 1996-08-14 | $7700.00 | Window Closed / Lapsed |