Migration imaging, optionally with dyes or pigments to effect bleaching
US5614340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1993 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Sep 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G17/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A bleachable composition, including an acid photogenerator and a near-infrared radiation-absorbing dye or pigment, is utilized in a method of migration imaging to prevent unwanted absorptions. This composition can be incorporated either in the thermoplastic imaging surface layer of the imaging element, in the marking particles applied to the element, or both. Alternatively, the components of the bleachable composition can be separated with one in the thermoplastic imaging surface layer and the other in the marking particles. After the imaging element is marked and exposed with near-infrared radiation, the bleachable composition caused exposed portions of the imaging element to be bleached. If further bleaching is needed, the element can subsequently be exposed with near-ultraviolet radiation. A migration imaging method, which does not employ the bleachable composition of the present invention, wherein marking particles are magnetically attracted to the imaging element, is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.