Camera-ready copy sheet for lithograpic printing plate
AssigneeFuji Photo Film Co., Ltd.
InventorsTakao Nakayama, Seishi Kasai, Hiroyuki Ohishi
Life of this patent
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Abstract
The present invention provides for a camera-ready copy sheet to be inserted between a plate cylinder and a lithographic printing plate at least the back side of which is made of a non-metallic material. The copy sheet has asperities of a predetermined shape on the front side that are urged against the back side of the lithographic printing plate to depress it. The height of the projections in the asperities ranges from 5 μm to 50 μm. The sum per unit area of maximum cross-sectional areas of planes in the projections that are parallel to the surface of the sheet ranges from 0.2% to 4% of the unit area.
Claims1
A camera-ready copy sheet to be inserted between a plate cylinder and a lithographic printing plate at least the back side of which is made of a non-metallic material,
- said copy sheet having asperities of a predetermined shape on the front side that are urged against the back side of the lithographic printing plate to depress it, a height of the projections in the asperities ranging from 5 μm to 50 μm, and the sum per unit area of maximum cross-sectional areas of planes in said projections that are parallel to the surface of the sheet ranging from 0.2% to 4% of the unit area.
Dependencies are inferred from the claim text.