Sub-surface marking
US5206496A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1991 |
| Grant date | Apr 27, 1993 |
| Priority date | — |
| Expiry date | Aug 15, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/442
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for providing a body of material (14) with sub-surface marking in the form of an area of increased opacity to electromagnetic radiation. The method includes directing at a surface of the body (14) a high energy density beam (12, 26) to which the material (14) is transparent, and bringing the beam (12,26) to a focus at a location spaced from the surface and within the body (14) so as to cause localized ionization of the material (14). In a prefered embodiment the apparatus includes a laser (10) as a high energy density beam source and provides means (36, 38) to move the focus of the beam (12,26) relative to the body (14) so as to enable the mark to be of a predetermined shape.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.