US3927409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multistage thin film toning system for developing charged images
Assignee: Varian Medical Systems Inc
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Filing: 1972-05-01
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Granted: 1975-12-16
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Expires: 1992-05-01
Abstract
Abstract During development of the electrostatic image, fresh toner is applied to the electrostatically charged paper by removing the depleted boundary layer of toner. The moving paper establishes a drag force on the toner forming a boundary layer which acts as a surface barrier preventing the migration of new toner particles to the paper. The development of the electrostatic image is completed in stages, each stage containing a toning mechanism to apply the toner and a squeegee mechanism to remove the toner boundary layer. In the preferred embodiment, the initial squeegee mechanism is a stationary bar, and the final squeegee mechanism is a roller squeegee partially formed by a paper drive roller.
Inventors
- 👤 Heino Kase
- 👤 Edward W Marshall
- 👤 Survrat Kirtikar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:35
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/10; G03G15/11
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
174 words
A recording device for forming a charge image on the charge retentive surface of a recording medium and toning the charge image with toner particles dispersed in a carrier liquid, comprising the combination: means for moving the recording medium relative to the recording device along a path of motion; means for forming a charge image on the charge retentive surface of the recording medium; a plurality of liquid toner applying means spaced from one another along the path of motion of said recording medium, each of said toner applying means arranged to apply a thin film of toner to the charge image on the recording medium; a. liquid toner squeegee means positioned between each of the spaced toner applying means to remove the thin film of toner from the charge retentive surface before the toner becomes substantially depleted of toner particles; and final liquid toner squeegee means positioned subsequent to the last toner applying means along the path of motion to remove the thin film of toner applied by the last toner applying means.
Claim 2
Dependent Claim
174 words
A recording device for forming a charge image on the charge retentive surface of a recording medium and toning the charge image with toner particles dispersed in a carrier liquid, comprising the combination: means for moving the recording medium relative to the recording device along a path of motion; means for forming a charge image on the charge retentive surface of the recording medium; a plurality of liquid toner applying means spaced from one another along the path of motion of said recording medium, each of said toner applying means arranged to apply a thin film of toner to the charge image on the recording medium; a. liquid toner squeegee means positioned between each of the spaced toner applying means to remove the thin film of toner from the charge retentive surface before the toner becomes substantially depleted of toner particles; and final liquid toner squeegee means positioned subsequent to the last toner applying means along the path of motion to remove the thin film of toner applied by the last toner applying means.
Claim 3
Dependent Claim
69 words
The recording device of claim 1, wherein the charge image is formed on the underneath side of the recording medium and the plurality of toner applying means flow the toner upward into contact with the underneath side of the recording medium in sufficient quantity to form a thin toner film the thickness of which is determined by the surface tension of the toner independently of the toner flow rate.
Claim 4
Dependent Claim
85 words
The recording device of claim 2, wherein the plurality of toner applying means are formed by a slot opening at the top of an upwardly directed channel extending across the recording medium generally transverse of the direction of web motion, the leading edge of the slot opening extending slightly higher than the trailing edge of the slot opening to form a bar type squeegee which removes the thin film of toner from the recording medium immediately prior to applying toner thereto from the slot opening.
Claim 5
Dependent Claim
32 words
The recording device of claim 3, wherein the leading edge of the initial toner slot opening extends higher than the trailing edge thereof to engage the recording medium and prevent toner leakage.
Claim 6
Dependent Claim
55 words
The recording device of claim 1, wherein a drive roller is provided for moving the recording medium, and wherein the final squeegeeing means is a squeegee roller engaging the recording medium against the drive roller for moving and maintaining tension in the recording medium and for pressing the toner film off of the recording medium.
Claim 7
Dependent Claim
49 words
The recording device of claim 5, wherein the plurality of squeegeeing means positioned between the toner applying means are bar type squeegees which scrape the thin toner film from the recording medium which is held in tension against the bar type squeegees by the drive roller and squeegee roller.
Claim 8
Dependent Claim
45 words
The recording device of claim 1, wherein the thin film of toner applied by each applying means is removed from the charge retentive suRface by the subsequent squeegee means before the charge image available at the time of each toner application becomes 50 percent toned.
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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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |