Methods and devices determine an eye strain indicator. In one aspect, an augmented reality (AR) device wearable by a user includes an image sensor and a processor coupled to the image sensor. The processor receives image data from the image sensor, determine that a display is within a field of view (FOV) of the AR device, determine an eye strain indicator based on the determination that the display is within the FOV of the AR device, and provide the eye strain indicator to the user.

Methods and devices determine an eye strain indicator. In one aspect, an augmented reality (AR) device wearable by a user includes an image sensor and a processor coupled to the image sensor. The processor receives image data from the image sensor, determine that a display is within a field of view (FOV) of the AR device, determine an eye strain indicator based on the determination that the display is within the FOV of the AR device, and provide the eye strain indicator to the user.

A single photon avalanche diode (SPAD) has a cathode coupled to a high voltage supply and an anode coupled to a first node. A photodetection circuit includes: a first n-channel transistor having a drain coupled to the first node, a source coupled to ground, and a gate coupled to a third node; a second n-channel transistor having a drain coupled to the first node, a source coupled to ground, and a gate coupled to a second node; and an inverter having an input coupled to the first node and an output coupled to an intermediate node. A current starved inverter has an input coupled to the intermediate node and an output coupled to the second node, a logic gate has inputs coupled to the intermediate node and the second node, and an output coupled to the third node.

A single photon avalanche diode (SPAD) has a cathode coupled to a high voltage supply and an anode coupled to a first node. A photodetection circuit includes: a first n-channel transistor having a drain coupled to the first node, a source coupled to ground, and a gate coupled to a third node; a second n-channel transistor having a drain coupled to the first node, a source coupled to ground, and a gate coupled to a second node; and an inverter having an input coupled to the first node and an output coupled to an intermediate node. A current starved inverter has an input coupled to the intermediate node and an output coupled to the second node, a logic gate has inputs coupled to the intermediate node and the second node, and an output coupled to the third node.

Disclosed herein is a device including at least one photoconductor configured for exhibiting an electrical resistance R.sub.photo dependent on an illumination of a light-sensitive region of the photoconductor; at least one photoconductor readout circuit, where the photoconductor readout circuit is configured for determining a differential voltage related to changes of the electrical resistance R.sub.photo of the photoconductor, where the photoconductor readout circuit includes at least one bias voltage source configured for applying at least one periodically modulated bias voltage to the photoconductor such that the electric output changes its polarity at least once; and at least one electrical circuit configured to balance the differential voltage at a given illumination level.

An electronic shelf label, which comprises: a display unit, which is designed for displaying image content, and a communication module, which is designed for wireless communication for the purpose of receiving image data, which represent the image content, and for transferring the image data to the display unit,
characterized in that a detector unit is provided, which is designed for detecting an incorrect positioning, which differs from a desired positioning, of the electronic shelf label, and for outputting an action signal when the incorrect positioning is detected, and in that the electronic shelf label is designed to change the image content when the action signal is present.

An electronic shelf label, which comprises: a display unit, which is designed for displaying image content, and a communication module, which is designed for wireless communication for the purpose of receiving image data, which represent the image content, and for transferring the image data to the display unit,
characterized in that a detector unit is provided, which is designed for detecting an incorrect positioning, which differs from a desired positioning, of the electronic shelf label, and for outputting an action signal when the incorrect positioning is detected, and in that the electronic shelf label is designed to change the image content when the action signal is present.

A method of measuring light intensity comprising exposing a photodiode to light to cause the photodiode to provide a current of a first polarity, supplying said current to an integrator to integrate said current to provide an integrated output voltage, and comparing the output voltage with a threshold voltage. Charge packages of opposite polarity are applied to said first polarity to reset the integration voltage prior to the start of the integration time. At the end of the integration time, the photodiode is disconnected from said integrator and a reference voltage coupled to the integrator input, whilst a resistance is coupled into the circuit until the comparison signal switches. The comparison signal is monitored to measure a time between the end of the integration time and the switching of the comparison signal to provide a measure of a residual voltage.

A method of measuring light intensity comprising exposing a photodiode to light to cause the photodiode to provide a current of a first polarity, supplying said current to an integrator to integrate said current to provide an integrated output voltage, and comparing the output voltage with a threshold voltage. Charge packages of opposite polarity are applied to said first polarity to reset the integration voltage prior to the start of the integration time. At the end of the integration time, the photodiode is disconnected from said integrator and a reference voltage coupled to the integrator input, whilst a resistance is coupled into the circuit until the comparison signal switches. The comparison signal is monitored to measure a time between the end of the integration time and the switching of the comparison signal to provide a measure of a residual voltage.

Embodiments of the present invention provide a unique new approach to generating operating condition information used for assessing flow assurance and structural integrity. More specifically, apparatuses, systems and sensor housing assemblies configured in accordance with embodiments of the present invention utilize fiber optic sensors for enabling monitoring of operating condition information within one or more elongated tubular members within a subsea environment. To this end, such fiber optic sensors connected by lengths of optical fiber are strategically placed at a plurality of locations along a length of each elongated tubular member thereby allowing critical operating conditions such as strain, temperature and pressure of the elongated tubular member and/or a fluid therein to be monitored. A viscous media is used for mitigating attenuation associated with exposure of optical fiber exposed to forces generated by pressure within the subsea environment.