Laser driver and control circuit
US4950268A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 1, 1988 |
| Grant date | Aug 21, 1990 |
| Priority date | — |
| Expiry date | Nov 1, 2008 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2018/2272
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A control apparatus for a pumped rod-type laser includes an arc lamp disposed to illuminate the lasing medium, such as a NdYAG crystalline rod. The apparatus includes a full wave rectifier to power the arc lamp, and a MOSFET switching circuit to turn on and off the arc lamp power at controlled times during each half cycle of the power waveform so that the laser medium is pumped and optically discharged once during each half cycle of the power supply. The laser power output is measured by a photodetector during each half cycle, and the photodetector output is integrated and compared with a manually set, variable laser output power level. When the actual laser power reaches the preset power level, the comparator initiates turning off the MOSFET switching circuit power for that respective half cycle of the power waveform. The full wave rectified power supply also permits the use of 110 VAC utility power. The apparatus also includes safety circuits that permit laser operation only when the internal cooling system is operating, when the current to the arc lamp is below a maximum level, and when the temperature created by the laser illumination on a target is below a variable preset leve…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.