Patent US3729311A successfully refreshed from Google Patents.
US3729311A
Expired / Lapsed
US
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Electrostatic transfer method
Assignee: Xerox Corp
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Filing: 1971-07-15
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Granted: 1973-04-24
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Expires: 1991-07-15
Abstract
Abstract An improved method of successively transferring a plurality of powder images, such as toner images of different colors, from an electrostatic plate onto a single copy sheet by employing an electrically biased transfer drum to bring the copy sheet in contact with the electrostatic plate during successive transfer steps. During transfer of the first toner image, the transfer drum is biased at a first potential and during the transfer of all succeeding toner images, the transfer drum is biased at a potential greater than the first potential, the potential applied to the transfer drum during any one succeeding transfer step being of greater value than the potential applied thereto during the immediately preceding transfer step.
Inventors
- 👤 M Langdon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:36
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/01; G03G15/0105; G03G15/0131
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
26 words
The method of claim 1 including the further step of fixing said toner image to said receiving body upon the completion of the last transfer step.
Claim 2
Dependent Claim
228 words
In a xerographic process for reproducing color originals wherein the original is separated into a number of color components and each of the components is then recorded as a series of charged toner images on a moving photosensitive plate, the plate being adapted to move the color component images seriatim through an image transfer zone, the improvement comprising, arranging an electrically biased transfer member to move through the transfer zone wherein the transfer member electrically communicates with the charged toner images supported on the plate surface so as to attract the images from the plate towards said transfer member, securing a sheet of final support material to said transfer member to receive the images attracted thereto, advancing the sheet oN said transfer member repeatedly through the transfer zone in registration with each of the color component images supported on the plate surface whereby at least a portion of each successively transferred toner image placed on the support sheet is superimposed over a previously transferred image, and increasing the bias potential applied to the transfer member for each successive transfer step to compensate for changes in the electrical characteristics of the image receiving support sheet caused by the addition of previously transferred charged toner images thereto whereby each color component image is efficiently transferred from said plate to said receiving body to faithfully recreate the original input scene information.
Claim 3
Dependent Claim
28 words
The method of claim 3 further including the step of fixing the color component images to the final support sheet upon the completion of the final transfer operation.
Claim 4
Dependent Claim
29 words
The method of claim 3 further including the step of fixing the color component toner images to the final support sheet upon the completion of the final transfer operation.
Claim 5
Independent Claim
232 words
The method of creating a full color copy of a color original upon a sheet of final support material including separating the original color information into primary color components, recording a first color component as a charged toner image upon an image retaining plate, placing a sheet of final support material in overlying contact with said first color component image, establishing an electrical field within the contact zone to attract the first color component image from said plate to said sheet of final support material, removing said sheet from said plate and recording a second color component as a charged toner image on said plate, replacing the support sheet in overlying contact with the second color component image on said plate whereby at least a portion of said second color component image is superimposed in registration over said first image, establishing a second electrical field within the contact zone to attract the second color component image in superposition over said first color component image, said second electrical field being of a strength greater than said first electrical field to compensate for changes in the electrical characteristics of the final support material caused by the deposition of the first color component image thereon, removing the sheet from said plate and repeating the image recording and transfer steps to produce a full color rendition of the original subject matter on said final support sheet.
Claim 6
Dependent Claim
32 words
The method of claim 6 wherein the original subject matter is separated into the primary color components of red, green and blue and images thereof recorded with cyan, magenta and yellow toners.
Claim 7
Dependent Claim
24 words
The method of claim 7 wherein the strength of the electrical transfer field is increased uniformly after the completion of each image transfer step.
References Cited (Backward Citations)
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US2951443A
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US3531195A
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US3363555A
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US3413063A
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US3627523A
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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) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |