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US 4,950,268 AGranted
Laser driver and control circuit
AssigneeXintec Inc.
InventorJohn L. Rink
Life of this patent
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AssigneeXintec Inc.
InventorJohn L. Rink
Estimating the term…
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 level, and the like. A further safety circuit detects the presence of laser radiation in the area surrounding the laser to shut it off when laser light escapes from the system. For medical uses, this feature obviates the need for laser safety goggles for operational personnel.
A control and driving apparatus for a laser having an optical pumping device, comprising;
A control and driving apparatus for a laser having an optical pumping device, comprising;
A control and driving apparatus for a laser having an optical pumping device, comprising;
A control and driving apparatus for a laser having an optical pumping device, comprising;
A control and driving apparatus for a laser having an optical pumping device, comprising;
A control and driving apparatus for a laser having an optical pumping device, comprising;
A method for driving and controlling a laser having an optical pumping device, including;
A method for driving and controlling a laser having an optical pumping device, including;
A laser radiation area safety apparatus, including laser radiation detector means disposed to sense laser radiation in the area surrounding a laser, photodetector means directed to monitor ambient light in said area surrounding the laser and to generate an output signal, said photodetector means including filter means for preferentially transmitting light in the output band of the laser, said photodetector output signal comprising a function of the portion of the ambient light in said output band of the laser, means for shutting off operating power to the laser when said photodetector output signal is received, and sampling means for conducting said photodetector output signal to said means for shutting off said operatng power only during predetermined time periods.
A control circuit for a laser, comprising means for receiving an AC utility power signal and generating a low voltage AC analog signal thereof, rectifier means for generating a periodic DC pulse signal from said low voltage AC analog signal, first timing means actuated by said DC pulse signal for generating a first timing signal comprising a digital pulse signal having a high absolute value when said DC pulse signal falls below a preset cutoff value, second timing means for receiving said first timing signal and generating a second timing signal in response thereto, said second timing signal comprising a digital signal of brief pulses, each occurring at the termination of each of said first timing signal pulses, and third timing means for receiving said second timing signal and generating a third timing signal in response thereto, said third timing signal comprising a digital signal of pulses each initiated by the cessation of one of said second timing signal pulses, switching means connected to deliver laser operating power to a laser, said switching means receiving said third timing signal and actuated to deliver laser operating power in response to receipt of each of said third timing signal pulses whereby the laser is operated in a pulsed mode with each laser pulse corresponding to one of said third timing signal pulses.
Dependencies are inferred from the claim text.