Pressurized screen assembly for exposure of a continuous tone image
US5019866A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 11, 1989 |
| Grant date | May 28, 1991 |
| Priority date | — |
| Expiry date | Oct 11, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/04027
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a reprographic or graphic arts application halftoned latent images of a continuous tone original image are created by imagewise exposure of a photosensitive member through a pressurized screen assembly. A transparent platen supports the original with one or more lamps being provided to illuminate the original resting on the platen. The light image produced is transmitted by an optical system through the pressurized screen assembly to the image plane of a photosensitive member to create the latent image. A pressurized cell within the screen assembly prevents sagging of the screen such that in the image plane of the projected image, the spacing of the halftone imaged pattern is uniform. A single blower system is provided to supply either a negative or positive pressure for the cell, depending upon the direction of sag.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.