Eye safety logic with compensation for transient conditions

摘要

An eye safety detection circuit for use in a laser transmitter. The eye safety detection circuit shuts the laser down if the laser is emitting excessive optical energy to the point of being unsafe to a user. The eye safety detection circuit includes a laser current detection circuit that is configured to detect when there is a potential that the laser is emitting light at levels that exceed a predetermined threshold. If the laser were to immediately turn off under this condition, the laser may be turned off prematurely. Instead, the eye safety detection circuit includes a timer circuit that causes the laser to cease operation only after one or more such conditions have been met for a predetermined period of time.