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US 5,339,737 AGranted
Lithographic printing plates for use with laser-discharge imaging apparatus
AssigneePresstek, Inc.
InventorsThomas E. Lewis, Michael T. Nowak, Kenneth T. Robichaud, Kenneth R. Cassidy
Life of this patent
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Abstract
Lithographic printing plates suitable for imaging by means of laser devices that emit in the near-infrared region. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.
Claims36
A lithographic printing member directly imageable by laser discharge, the member comprising:
- a. a topmost first layer which is polymeric;
- and
- b. a second layer underlying the first layer;
- and
- c. a substrate underlying the second layer;
- wherein
- d. the second layer is formed of a material which is subject to ablative absorption of imaging infrared radiation and the first layer is not;
- and
- e. the first layer and the substrate exhibit different affinities for at least one printing liquid selected from the group consisting of ink and an adhesive fluid for ink.
6 more elements
Dependencies are inferred from the claim text.