Patent ID: 11960094
Assignee: GOOGLE LLC
Field: Optics (Instruments)
Classification: CPC G  H | IPC F  G  H

Claim 12:
13. A wearable heads-up display, comprising:
a laser module including at least one laser source;
a lightguide having at least one optical path defined therein;
at least one light source to output a test light into the lightguide;
a photodetector positioned proximate to a perimeter of the lightguide to detect an intensity of a portion of the test light emitted from within the lightguide; and
a laser safety circuit coupled to a power source and the photodetector, the laser safety circuit to reduce or shut off a supply of electrical power from the power source to the laser module in response to an output signal from the photodetector indicating that the detected intensity is below a threshold.