Patent US3905331A successfully refreshed from Google Patents.
US3905331A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for precluding trailing of toner images in electrophotography of the wet type
Assignee: Ricoh Co Ltd
•
Filing: 1973-08-17
•
Granted: 1975-09-16
•
Expires: 1993-08-17
Abstract
Abstract A means for precluding trailing of toner images during development in electrophotographic apparatus of the wet type operating at a developing rate of more than 150 mm./sec., which means comprises a pair of rollers disposed along the path of travel of a copy sheet released from the developing liquid tank, one roller made of metal with its peripheral surface arranged to come into contact with the image bearing surface of the copy sheet, the other disposed opposite the metallic roller with its peripheral surface contacting the back surface of the copy sheet. The peripheral surface of the latter roller is of a material having a surface resistance of less than 1 X 107 ohm-cm., and both rollers are maintained at the same potential or grounded, which condition is effective to preclude blurring of a toner image on the copy sheet.
Inventors
- 👤 Tsuguo Kimura
- 👤 Setsuo Soga
- 👤 Toshio Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:38
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
143 words
In an electrophotographic apparatus of the wet type with a developing device having: a. a developing tank containing developing liquid through which an exposed photosensitive sheet is passed; b. a metallic roller disposed at the exit of the developing tank for contacting the image bearing surface of the passing photosensitive sheet; and c. a squeegee roller disposed opposite the metallic roller for cooperatively contacting the passing photosensitive sheet at its back surface; wherein the improvement comprises: d. means for rotating said rollers at a developing rate of greater than 150 mm./sec.; e. means for producing on the peripheral surface of the squeegee roller contacting the back of the photosensitive sheet, a surface resistance of less than 1 X 107 ohm-cm; and f. means for maintaining said squeegee roller at the same potential as said metallic roller to preclude the trailing of toner images.
Claim 2
Dependent Claim
143 words
In an electrophotographic apparatus of the wet type with a developing device having: a. a developing tank containing developing liquid through which an exposed photosensitive sheet is passed; b. a metallic roller disposed at the exit of the developing tank for contacting the image bearing surface of the passing photosensitive sheet; and c. a squeegee roller disposed opposite the metallic roller for cooperatively contacting the passing photosensitive sheet at its back surface; wherein the improvement comprises: d. means for rotating said rollers at a developing rate of greater than 150 mm./sec.; e. means for producing on the peripheral surface of the squeegee roller contacting the back of the photosensitive sheet, a surface resistance of less than 1 X 107 ohm-cm; and f. means for maintaining said squeegee roller at the same potential as said metallic roller to preclude the trailing of toner images.
Claim 3
Dependent Claim
16 words
Apparatus as in claim 1 wherein said squeegee roller is made entirely of a resilient material.
Claim 4
Dependent Claim
16 words
Apparatus as in claim 1 wherein said squeegee roller is made entirely of a hard material.
Claim 5
Dependent Claim
27 words
Apparatus as in claim 1 wherein the surface resistance of the squeegee roller is in the range from 1 X 106 ohm-cm to 1 X 102 ohm-cm.
Claim 6
Dependent Claim
20 words
Apparatus as in claim 1 wherein the squeegee roller is a metallic roller with a peripheral layer of resilient material.
Claim 7
Dependent Claim
20 words
Apparatus as in claim 1 further comprising a pair of squeeze rOllers positioned downstream of said metallic and squeegee rollers.
Claim 8
Dependent Claim
33 words
Apparatus as in claim 1, wherein said developing liquid contains toner particles of a particular polarity and the polarity of the potential on said rollers is opposite to that on said toner particles.
References Cited (Backward Citations)
US3155546A
Cited
US3556653A
Cited
US3305459A
Cited
US3799791A
Cited
US3407786A
Cited
US3556050A
Cited
US3653756A
Cited
US3687708A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |