Apparatus for Monitoring Mechanical Integrity of an Eye-safety Component of an Illuminator
An apparatus for monitoring mechanical integrity of an eye-safety component of an illuminator is disclosed. The apparatus comprises a sensor, operable to sense a photoacoustic effect in the eye-safety component during operation of the illuminator and to output a signal representative of the sensed photoacoustic effect, and a processor. The processor is operable to: monitor the signal from the sensor; determine if the signal comprises at least one parameter that falls outside of a pre-determined acceptable range, the pre-determined acceptable range being indicative of mechanical integrity of the eye-safety component; and initiate a safety action in response to a determination that the at least one parameter falls outside of the pre-determined acceptable range thereby indicating a loss of mechanical integrity.
1 . An apparatus for monitoring mechanical integrity of an eye-safety component of an illuminator, the apparatus comprising:
a sensor operable to sense a photoacoustic effect in the eye-safety component during operation of the illuminator and to output a signal representative of the sensed photoacoustic effect; and
a processor operable to:
monitor the signal from the sensor;
determine if the signal comprises at least one parameter that falls outside of a pre-determined acceptable range, the pre-determined acceptable range being indicative of mechanical integrity of the eye-safety component; and
initiate a safety action in response to a determination that the at least one parameter falls outside of the pre-determined acceptable range thereby indicating a loss of mechanical integrity.
2 . The apparatus of claim 1 wherein the sensor is configured to sense a sound wave formed by the photoacoustic effect.
3 . The apparatus of claim 2 further comprising a phononic structure configured to improve a signal-to-noise ratio of the sound wave.
4 . The apparatus of claim 1 wherein the processor is further operable to detect a change in environmental conditions within the illuminator based on the signal from the sensor.
5 . The apparatus of claim 1 wherein the processor is operable to initiate the safety action by transmitting an instruction to the illuminator to modify an intensity of illumination.
6 . The apparatus of claim 1 wherein the processor is operable to initiate the safety action by transmitting an instruction to the illuminator to cease illumination.
7 . The apparatus of claim 1 wherein the sensor comprises a microphone.
8 . The apparatus of claim 1 further comprising one or more of an amplifier; a filter; a lock-in detector; and an acceptable range detector.
9 . An illuminator comprising:
at least one emitter;
an eye-safety component providing a shield between the at least one emitter and a user; and
the apparatus of claim 1 .
10 . The illuminator of claim 9 further comprising a modulator configured to modulate a light output from at least one of the at least one emitter at a pre-determined frequency and wherein the processor is operable to use the pre-determined frequency in a lock-in detection method and/or a gated detection method when monitoring the signal from the sensor.
11 . The illuminator of claim 9 wherein the at least one emitter comprises an illumination emitter and the sensor is operable to sense a photoacoustic effect resulting from operation of the illumination emitter.
12 . The illuminator of claim 9 wherein the at least one emitter comprises a monitoring emitter and the sensor is operable to sense a photoacoustic effect resulting from operation of the monitoring emitter.
13 . The illuminator of claim 9 wherein the sensor is arranged to sense the photoacoustic effect in the eye-safety component directly.
14 . The illuminator of claim 9 wherein the sensor is arranged to sense the photoacoustic effect in the eye-safety component indirectly by receiving an input via a waveguide or other medium.
15 . The illuminator of claim 9 wherein the at least one emitter comprises a laser.
16 . The illuminator of claim 9 wherein the eye-safety component comprises a glass substrate and/or a diffuser.
17 . A device comprising one of an apparatus according to claim 1 and an illuminator according to claim 9 .
18 . A method for monitoring mechanical integrity of an eye-safety component of an illuminator, the method comprising:
obtaining, from a sensor, a signal representative of a sensed photoacoustic effect in the eye-safety component during operation of the illuminator;
monitoring the signal;
determining if the signal comprises at least one parameter that falls outside of a pre-determined acceptable range, the pre-determined acceptable range being indicative of mechanical integrity of the eye-safety component; and
initiating a safety action in response to a determination that the at least one parameter falls outside of the pre-determined acceptable range thereby indicating a loss of mechanical integrity.
19 . The method of claim 18 further comprising establishing the pre-determined acceptable range using an artificial neural network.
20 . A non-transitory computer-readable medium having stored thereon program instructions for causing at least one processor to perform the method according to claim 18 .