Back to results
US 5,353,705 AGranted
Lithographic printing members having secondary ablation layers for use with laser-discharge imaging apparatus
AssigneePresstek, Inc.
InventorsThomas E. Lewis, Michael T. Nowak, Kenneth T. Robichaud
Life of this patent
Estimating the term…
Abstract
Lithographic printing plates suitable for imaging by means of laser devices. Laser output ablates one or more plate layers, 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. The plates also include a secondary ablation layer that ablates only partially, and in a controlled fashion, as a result of destruction of overlying layers.
Claims18
A lithographic printing member directly imageable by laser discharge, the member comprising:
- a. a topmost first layer;
- and
- b. a second layer underlying the first layer, the second layer being characterized by ablative absorption of laser radiation;
- c. a third layer underlying the second layer, the third layer:
- i. being substantially transparent to the laser radiation;
- ii. being ablated only partially in response to ablation of the second layer;
- and
- iii. differing from the first layer in its affinity for at least one printing liquid selected from the group consisting of ink and a fluid that repels ink.
5 more elements
Dependencies are inferred from the claim text.