US3953618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic image developing process
Assignee: ELSCINT IMAGING Inc
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Filing: 1974-09-20
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Granted: 1976-04-27
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Expires: 1994-09-20
Abstract
Abstract An electrostatic image developer of the powder cloud type incorporating an image field screen or plate adjacent the receptor sheet carrying the electrostatic image, and including means for varying the image field plate potential and spacing during the developing cycle for improved contrast in the resultant visual picture. A method of developing including varying the image field screen potential and spacing during the developing cycle.
Inventors
- 👤 Eric P. Muntz
- 👤 Murray S. Welkowsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:34
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0803
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
171 words
A process for developing an electrostatic image on a receptor sheet, including the steps of: producing a cloud of positive and negative charged toner powder particles; attracting said toner particles of one polarity to a first electrode remote from the receptor sheet and said toner particles of the opposite polarity to a second apertured electrode positioned adjacent the side of the receptor sheet bearing the electrostatic image and between the receptor sheet and the first electrode by applying an electric potential across the first and second electrodes; attracting the toner particles of said opposite polarity through the second apertured electrode to deposit the toner particles onto the electrostatic image on the receptor sheet at localities having a charge potential with respect to the potential of the second electrode; varying the potential of the second electrode as a function of time during the deposition of the toner particles; and varying the distance between the second electrode and the receptor sheet as a function of time during the deposition of the toner particles.
Claim 2
Dependent Claim
171 words
A process for developing an electrostatic image on a receptor sheet, including the steps of: producing a cloud of positive and negative charged toner powder particles; attracting said toner particles of one polarity to a first electrode remote from the receptor sheet and said toner particles of the opposite polarity to a second apertured electrode positioned adjacent the side of the receptor sheet bearing the electrostatic image and between the receptor sheet and the first electrode by applying an electric potential across the first and second electrodes; attracting the toner particles of said opposite polarity through the second apertured electrode to deposit the toner particles onto the electrostatic image on the receptor sheet at localities having a charge potential with respect to the potential of the second electrode; varying the potential of the second electrode as a function of time during the deposition of the toner particles; and varying the distance between the second electrode and the receptor sheet as a function of time during the deposition of the toner particles.
Claim 3
Dependent Claim
61 words
The process of claim 1 wherein the potential of the second electrode is changed from a first predetermined value to a second predetermined value during the deposition of the toner particles, and the distance between the second electrode and the receptor sheet is changed from a first predetermined value to a second predetermined value during the deposition of the toner particles.
Claim 4
Dependent Claim
76 words
The process of claim 1 wherein the ratio (V max -Vo max )/d min at the start of deposition of the toner particles is about equal to the ratio (V min-Vo min )/d max at the end of the deposition of the toner particles, where V is the potential of the charge on the receptor sheet, Vo is the potential of the second electrode, and d is the distance between the receptor sheet and second electrode.
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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) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |