Method of preparing a contoured plate
US4891302A · kind A · utility
Inventors
Key dates
| Filing date | Sep 9, 1988 |
| Grant date | Jan 2, 1990 |
| Priority date | — |
| Expiry date | Sep 9, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/2022
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Method of preparing a contoured plate by selectively hardening a photopolymer plate in a zone which is adjacent the lower surface of the plate and increases continuously in thickness from one portion of the plate to another by a first exposure of the upper surface of the plate to a quantity of light energy which increases continuously per unit area of the surface from said one portion of the plate to the other. Discrete portions of the upper surface of the plate are masked in the portions on which it is desired to form a recessed design, and the non-masked portions of the plate are hardened by a second exposure of its upper surface to light energy, so that the masked portions remain unhardened from their upper surface to the upper region of said hardened zone. The unhardened portions are removed to provide a recessed design in the upper surface of the plate. The design varies continuously in depth independently of the width of the design.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.