Multiple xeroprinted copies from a single exposure using photosensitive film buffer element
US4898797A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1988 |
| Grant date | Feb 6, 1990 |
| Priority date | — |
| Expiry date | Jul 18, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G13/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed is a method of improving the sharpness of multiple copies made from a single imagewise exposure using an electrostatographic film buffer element having an insulating layer in between a conductive layer and a photoconductive layer, where the element is simultaneously charged and imagewise exposed and then uniformly exposed with light to bury the charges. The improvement consists of performing the uniform exposure with light that is absorbed by the photoconductive layer and does not penetrate through the photoconductive layer to the insulating layer. Also disclosed is apparatus useful for making multiple copies which comprises an electrostatographic film buffer element which comprises, (A) in order, a conductive layer, an insulating layer, and a photoconductive layer, (B) means for simultaneously charging the imagewise exposing the element, and (C) means for uniformly exposing the element with light that is absorbed by the photoconductive layer and does not penetrate through the photoconductive layer to the insulating layer. Also disclosed is a method of making multiple electrostatographic copies comprising simultaneously charging and imagewise exposing an electrostatograph…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.