Light obstruction can be detected using a light obstruction sensor. In one example implementation according to aspects of the present disclosure, a computer-implemented method includes receiving, by a light obstruction sensor, light being emitted by a light source, a light level being associated with the light, and the light source and the light obstruction sensor being disposed in a light assembly. The method further includes determining, by a processing device, whether the light level exceeds a first threshold. The method further includes, responsive to determining that the light level exceeds the first threshold, determining that the light being emitted by the light source is at least partially impaired by an object. The method further includes validating, by the processing device, the determination that the light source is at least partially impaired by the object to confirm whether the light source is at least partially impaired by the object.

Light obstruction can be detected using a light obstruction sensor. In one example implementation according to aspects of the present disclosure, a computer-implemented method includes receiving, by a light obstruction sensor, light being emitted by a light source, a light level being associated with the light, and the light source and the light obstruction sensor being disposed in a light assembly. The method further includes determining, by a processing device, whether the light level exceeds a first threshold. The method further includes, responsive to determining that the light level exceeds the first threshold, determining that the light being emitted by the light source is at least partially impaired by an object. The method further includes validating, by the processing device, the determination that the light source is at least partially impaired by the object to confirm whether the light source is at least partially impaired by the object.

Two separate schemes are used for detecting light intensity in low light conditions and high light conditions. In high light conditions, two threshold voltages are set and the time between the crossing of a sensor voltage at the two threshold voltages is measured to determine the light intensity in the high light conditions. In low light conditions, a comparator is used to compare the voltage level of the sensor voltage relative to a reference voltage that increase over time. The time when the reference voltage reaches the sensor voltage level is detected to determine the light intensity in the low light conditions.

Two separate schemes are used for detecting light intensity in low light conditions and high light conditions. In high light conditions, two threshold voltages are set and the time between the crossing of a sensor voltage at the two threshold voltages is measured to determine the light intensity in the high light conditions. In low light conditions, a comparator is used to compare the voltage level of the sensor voltage relative to a reference voltage that increase over time. The time when the reference voltage reaches the sensor voltage level is detected to determine the light intensity in the low light conditions.

An apparatus, having a transmitted light power/energy monitor configured to monitor transmitted power/energy of light transmitted by a light source, and a controller configured to determine and control a maximum transmit light time based on the transmitted light power/energy and a transmit light power/energy threshold based on time.

An object detector including a light-emitting system to emit light to an object, a light detector, a signal detector, and a threshold adjuster. The light detector receives the light emitted from the light-emitting system and reflected by the object, and output a signal. The signal detector detects the signal output from the light detector based on a threshold value of voltage. The threshold adjuster changes the threshold value between when the light-emitting system emits light to a part of a light-emission range of the light-emitting system and when the light-emitting system emits light to other part of the light-emission range other than the part of the light-emission range.

An object detector including a light-emitting system to emit light to an object, a light detector, a signal detector, and a threshold adjuster. The light detector receives the light emitted from the light-emitting system and reflected by the object, and output a signal. The signal detector detects the signal output from the light detector based on a threshold value of voltage. The threshold adjuster changes the threshold value between when the light-emitting system emits light to a part of a light-emission range of the light-emitting system and when the light-emitting system emits light to other part of the light-emission range other than the part of the light-emission range.

An image sensor comprises a plurality of pixels, each pixel including: a light-receiving element that outputs an output voltage that varies in response to a photon entering; at least one comparator that compares the output voltage with a plurality of mutually-different threshold voltages and outputs a single signal each time the output voltage varies so as to exceed either of the threshold voltages; and at least one counter that counts a number of signals output by the comparator upon comparing the output voltage with the plurality of threshold voltages and outputs a count value, for each of the threshold voltages.

A laser lighting module for a vehicle headlight includes at least one laser, a scanning arrangement, a light conversion device, a safety mirror, a safety detector and a safety controller. The laser emits light in a first wavelength range and the scanning arrangement moves a beam of the light within a scanning solid angle so a spot of the light moves across the light conversion device. The light conversion device converts a fraction of the light to converted light in a different wavelength range than the first and emits a mixture of transmitted and converted light. The safety mirror is arranged within the scanning solid angle such that at least 90% of the transmitted light hits the safety mirror. The safety controller receives the control signal, generated by the safety detector from the safety detection light, and switches off the laser if the control signal exceeds a first threshold value.

A system, apparatus and method of improved measurement of the SPF factor of sunscreen compositions. In one embodiment, a method of measuring the protection of a sunscreen composition includes exposing skin to a known intensity of light, measuring the amount of remitted light from the skin, applying sunscreen to the skin, exposing the skin to which the sunscreen has been applied the known intensity of emitted light of the spectrum of light from which the sunscreen is intended to protect the skin, measuring the amount of light remitted from the skin, and calculating a UltraViolet-A Protection Factor (UVA-PF) of the sunscreen by comparing the amount of light remitted from the skin with the sunscreen to the amount of light remitted from the skin without the sunscreen.