US4245555A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic transfer process for producing lithographic printing plates
Assignee: Research Laboratories of Australia Pty Ltd
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Filing: 1978-09-11
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Granted: 1981-01-20
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Expires: 1998-09-11
Abstract
Abstract A system for producing lithographic printing plates by image transfer from either a right way or a wrong way reading recording member, which comprise a conductive base having first and second register means thereon the register means being arranged and positioned respectively so that the first engages and locates an image receiving member and a recording member on the base and the second engages and locates an offset member on the base, the register means being spaced apart to allow access to the first register means while the offset member is engaged on the second register means, a roller having at least a conductive core arranged to move over the base outwards from the register means and return, and means to apply an electrical field between the roller and base and to change the polarity to prevent electrostatic image transfer during the outward movement of the roller and to cause electrostatic image transfer during the return movement of the roller.
Inventors
- 👤 Julia M. Alston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:27
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/18; Y; Y10; Y10S; Y10S101/00; Y10S101/36; Y10S101/37
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
389 words
The method of producing lithographic printing plates which comprises: (a) placing a receiving member on a base engaged on first register means to locate the said receiving member on the said base, (b) engaging a recording member on said register means to contact said receiving member, said recording member containing an electrostatically transferrable image on the face thereof away from said receiving member, (c) engaging an offset member on an ancillary register means to contact said recording member, said offset member contacting the face of said recording member containing said transferrable image, (d) passing a roller with at least a conductive centre over said base in one direction to press the faces of the said offset member and the said recording member into intimate contact while applying between said roller and said base an electrical field with a polarity in relation to said roller which prevents electrostatic image transfer, (e) returning said roller in the opposite direction while reversing the polarity of said electrical field to electrostatically transfer the said image from the said recording member to the said offset member to form a transferrable image thereon, (f) separating the said offset member containing said transferrable image from the said recording member but retaining said offset member registered on said ancillary register means, (g) removing the said recording member from the said receiving member and the first said register means while retaining said offset member on said ancillary register means, (h) placing the said offset member on the said receiving member while retaining said offset member registered on said ancillary register means, said offset member containing said transferrable image on the face thereof contacting said receiving member. (i) passing the said roller over said base in one direction to press the faces of the said offset member and the said receiving member into intimate contact while applying between said roller and said base an electrical field with a polarity in relation to said roller which prevents electrostatic image transfer, (j) returning said roller in the opposite direction while reversing the polarity of said electrical field to electrostatically transfer the said image from the said offset member to the said receiving member, (k) separating the said offset member from the said receiving member, and (l) fixing the said image on the said receiving member to form a lithographic printing plate.
Claim 2
Independent Claim
389 words
The method of producing lithographic printing plates which comprises: (a) placing a receiving member on a base engaged on first register means to locate the said receiving member on the said base, (b) engaging a recording member on said register means to contact said receiving member, said recording member containing an electrostatically transferrable image on the face thereof away from said receiving member, (c) engaging an offset member on an ancillary register means to contact said recording member, said offset member contacting the face of said recording member containing said transferrable image, (d) passing a roller with at least a conductive centre over said base in one direction to press the faces of the said offset member and the said recording member into intimate contact while applying between said roller and said base an electrical field with a polarity in relation to said roller which prevents electrostatic image transfer, (e) returning said roller in the opposite direction while reversing the polarity of said electrical field to electrostatically transfer the said image from the said recording member to the said offset member to form a transferrable image thereon, (f) separating the said offset member containing said transferrable image from the said recording member but retaining said offset member registered on said ancillary register means, (g) removing the said recording member from the said receiving member and the first said register means while retaining said offset member on said ancillary register means, (h) placing the said offset member on the said receiving member while retaining said offset member registered on said ancillary register means, said offset member containing said transferrable image on the face thereof contacting said receiving member. (i) passing the said roller over said base in one direction to press the faces of the said offset member and the said receiving member into intimate contact while applying between said roller and said base an electrical field with a polarity in relation to said roller which prevents electrostatic image transfer, (j) returning said roller in the opposite direction while reversing the polarity of said electrical field to electrostatically transfer the said image from the said offset member to the said receiving member, (k) separating the said offset member from the said receiving member, and (l) fixing the said image on the said receiving member to form a lithographic printing plate.
Claim 3
Dependent Claim
58 words
The method of claim 1 wherein the said offset member is held in contact with the said roller around part of its periphery as the said roller is returning in said opposite direction after said electrostatic image transfers to thereby separate the said offset member firstly from the said recording member and secondly from the said receiving member.
Claim 4
Dependent Claim
67 words
The method of claim 1 wherein the said offset member is retained on the said ancillary register means by the said roller in its said rest position and wherein while the said recording member is removed from the said base and disengaged from the first said register means said offset member is also supported by a support member to allow access to the first said register means.
Claim 5
Independent Claim
438 words
The method of producing lithographic printing plates by image transfer which comprises: (a) placing a receiving member into registered contact with a base, (b) engaging a recording member in registered contact with said receiving member, said recording member containing a transferrable image on the face thereof away from said receiving member, (c) engaging an offset member in registered contact with said base to contact the image bearing face of said recording member, said offset member being engaged on register means on said base which are apart from and not used to engage said receiving member and said recording member, (d) passing a roller with at least a conductive centre over said base in one direction to press the faces of the said recording member and the said offset member into intimate contact while applying an electrical field between said roller and said base with a polarity in relation to said roller which prevents electrostatic image transfer, (e) returning said roller in the opposite direction while reversing the polarity of said electrical field to electrostatically transfer said image from said recording member to the said offset member to form a transferrable image thereon, (f) separating the said offset member from the said recording member by holding the said offset member in contact with the said roller around part of its periphery as the said roller is returning after said electrostatic image transfer but retaining said offset member registered to said base, (g) removing said recording member from contact with said receiving member and from register to said base while retaining said offset member registered to said base, (h) placing said offset member on the said receiving member while retaining said offset member registered to said base, said offset member containing said transferrable image on the face thereof contacting said receiving member, (i) passing said roller over said base in one direction to press the faces of the said offset member and the said receiving member into intimate contact while applying an electrical field between said roller and said base with a polarity in relation to said roller which prevents electrostatic image transfer, (j) returning said roller in the opposite direction while reversing the polarity of said electrical field to electrostatically transfer said image from the said offset member to the said receiving member, (k) separating the said offset member from the said receiving member by holding the said offset member in contact with the said roller around part of its periphery as the said roller is returning after said electrostatic image transfer, and (l) fixing the said image on the said receiving member to form a lithographic printing plate.
Claim 6
Independent Claim
438 words
The method of producing lithographic printing plates by image transfer which comprises: (a) placing a receiving member into registered contact with a base, (b) engaging a recording member in registered contact with said receiving member, said recording member containing a transferrable image on the face thereof away from said receiving member, (c) engaging an offset member in registered contact with said base to contact the image bearing face of said recording member, said offset member being engaged on register means on said base which are apart from and not used to engage said receiving member and said recording member, (d) passing a roller with at least a conductive centre over said base in one direction to press the faces of the said recording member and the said offset member into intimate contact while applying an electrical field between said roller and said base with a polarity in relation to said roller which prevents electrostatic image transfer, (e) returning said roller in the opposite direction while reversing the polarity of said electrical field to electrostatically transfer said image from said recording member to the said offset member to form a transferrable image thereon, (f) separating the said offset member from the said recording member by holding the said offset member in contact with the said roller around part of its periphery as the said roller is returning after said electrostatic image transfer but retaining said offset member registered to said base, (g) removing said recording member from contact with said receiving member and from register to said base while retaining said offset member registered to said base, (h) placing said offset member on the said receiving member while retaining said offset member registered to said base, said offset member containing said transferrable image on the face thereof contacting said receiving member, (i) passing said roller over said base in one direction to press the faces of the said offset member and the said receiving member into intimate contact while applying an electrical field between said roller and said base with a polarity in relation to said roller which prevents electrostatic image transfer, (j) returning said roller in the opposite direction while reversing the polarity of said electrical field to electrostatically transfer said image from the said offset member to the said receiving member, (k) separating the said offset member from the said receiving member by holding the said offset member in contact with the said roller around part of its periphery as the said roller is returning after said electrostatic image transfer, and (l) fixing the said image on the said receiving member to form a lithographic printing plate.
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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) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |