Lithographic plate making and printing process
Patent 4149464 Issued on April 17, 1979. Estimated Expiration Date: 
February 16, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 16, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesInventorsAssigneeApplicationNo. 05/769056 filed on 02/16/1977US Classes:101/450.1, Processes of lithographic printing101/211ProcessesExaminersPrimary: Coughenour, Clyde I.Attorney, Agent or FirmInternational ClassesB41M 3/00 (20060101)B41M 1/00 (20060101) B41M 1/06 (20060101) G03F 5/22 (20060101) G03F 5/00 (20060101) G03F 5/12 (20060101) AbstractAn improved two printing step process for reproducing visual subject matter including the making of a secondary printing plate with a positive image random pattern screen and printing a substrate sequentially and in registry with the secondary printing plate and a master printing plate made with a conventional half tone screen. The random pattern screen is a positive image phototransparency having a large plurality of irregularly shaped highlight areas and constrasting shadow areas per square inch, an optical density from about 0.17 to about 1.6, a contrast factor from about 0.75 to about 1.5 and a transparency factor from about 0.25 to about 0.60. The random pattern screen is made from a transparent plate having light disruptive projections on its surface. A negative and a positive phototransparency of the transparent plate are made while controlling exposure and developing conditions to produce a positive image screen having the desired characteristics. | |
