Patent ID: 8755420

Claim:
A circuit for limiting the operation of a laser-based device comprising: at least one laser diode, one or more safety circuits that detect fault conditions associated with laser pulses emitted by the at least one laser diode according to one or more pulse emission parameters, including at least one of: (a) a current limit circuit configured to detect an over-current fault condition associated with one or more emitted laser pulses, (b) a pulsewidth, limit circuit configured to detect a pulse duration fault condition associated with one or more emitted laser pulses, and (c) a pulse repetition frequency limit circuit configured to detect a pulse frequency fault condition associated with one or more emitted laser pulses, an interlock circuit responsive to any of the fault conditions associated with one or more emitted laser pulses for preventing the at least one laser diode from emitting a subsequent laser pulse or for terminating an ongoing laser pulse, and a safety circuit testing system that alters at least one of the pulse emission parameters in order to test whether at least one of the safety circuits that detects fault conditions associated with laser pulses emitted by the at least one laser diode is operating properly, wherein the testing performed by the safety circuit testing system is performed without emitting a laser pulse and independent of any emission by the at least one laser diode.