Laser power control with stretched initial pulses
US6151345A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 7, 1998 |
| Grant date | Nov 21, 2000 |
| Priority date | — |
| Expiry date | Jul 7, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB33Y30/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A laser power control system (150; 150') having a first pulse stretch capability, as may be used in a rapid prototyping system (100), is disclosed. According to one disclosed embodiment, a one-shot multivibrator (156) generates a pulse responsive to a gate signal (LON/LOFF.sub.--) indicating that the laser (110) is to be turned on. The pulse, which is of a selected duration suitable for achieving population inversion, is applied to the laser (110); upon the end of this pulse, pulse-width-modulation (PWM) control of the laser begins. According to another disclosed embodiment, a first pulse stretch store (166) retains a digital value corresponding to the duration by which the first PWM pulse is to be lengthened; adders (176; 178) add this digital value to the parameters indicated by the desired laser power signal (DLP) to ensure population inversion and laser output of the laser (110) in the first pulse.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.