Method and apparatus for equalizing power output in a laser marking system
US4727235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1987 |
| Grant date | Feb 23, 1988 |
| Priority date | — |
| Expiry date | Aug 5, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K15/1266
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Variations in laser output power are compensated for by increasing the on time of weaker output lasers relative to the more powerful lasers. To avoid nonlinearities where the object to be marked is a moving substrate, the on time pulses which control the lasers are centered about a single time reference point. Additionally, for high printing rates a pre-ionization technique is disclosed which is utilized to enable a laser to fire more quickly than would otherwise be possible. Pre-ionization may be used for every dot to be printed or only when a laser has not been fired during the previous printing "stroke" depending upon the stroke rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.