A wireless battery-powered daylight sensor for measuring a total light intensity in a space is operable to transmit wireless signals using a variable transmission rate that is dependent upon the total light intensity in the space. The sensor comprises a photosensitive circuit, a wireless transmitter for transmitting the wireless signals, a controller coupled to the photosensitive circuit and the wireless transmitter, and a battery for powering the photosensitive circuit, the wireless transmitter, and the controller. The photosensitive circuit is operable to generate a light intensity control signal in response to the total light intensity in the space. The controller transmits the wireless signals in response to the light intensity control signal using the variable transmission rate that is dependent upon the total light intensity in the space. The variable transmission rate may be dependent upon an amount of change of the total light intensity in the space. In addition, the variable transmission rate may be further dependent upon a rate of change of the total light intensity in the space.

What is disclosed are systems and methods of optical correction for pixel evaluation and correction for active matrix light emitting diode device (AMOLED) and other emissive displays. Optical correction for correcting for non-homogeneity of a display panel uses sparse display test patterns in conjunction with a defocused camera as the measurement device to avoid aliasing (moiré) of the pixels of the display in the captured images.

What is disclosed are systems and methods of optical correction for pixel evaluation and correction for active matrix light emitting diode device (AMOLED) and other emissive displays. Optical correction for correcting for non-homogeneity of a display panel uses sparse display test patterns in conjunction with a defocused camera as the measurement device to avoid aliasing (moiré) of the pixels of the display in the captured images.

An illumination device and method is provided herein for calibrating individual LEDs in the illumination device, so as to obtain a desired luminous flux and a desired chromaticity of the device over changes in drive current, temperature, and over time as the LEDs age. The calibration method may include subjecting the illumination device to a first ambient temperature, successively applying at least three different drive currents to a first LED to produce illumination at three or more different levels of brightness, obtaining a plurality of optical measurements from the illumination produced by the first LED at each of the at least three different drive currents, obtaining a plurality of electrical measurements from the photodetector and storing results of the obtaining steps within the illumination device to calibrate the first LED at the first ambient temperature. The plurality of optical measurements may generally include luminous flux and chromaticity, the plurality of electrical measurements may generally include induced photocurrents and forward voltages, and the calibration method steps may be repeated for each LED included within the illumination device and upon subjecting the illumination device to a second ambient temperature.

An illumination device and method is provided herein for calibrating individual LEDs in the illumination device, so as to obtain a desired luminous flux and a desired chromaticity of the device over changes in drive current, temperature, and over time as the LEDs age. The calibration method may include subjecting the illumination device to a first ambient temperature, successively applying at least three different drive currents to a first LED to produce illumination at three or more different levels of brightness, obtaining a plurality of optical measurements from the illumination produced by the first LED at each of the at least three different drive currents, obtaining a plurality of electrical measurements from the photodetector and storing results of the obtaining steps within the illumination device to calibrate the first LED at the first ambient temperature. The plurality of optical measurements may generally include luminous flux and chromaticity, the plurality of electrical measurements may generally include induced photocurrents and forward voltages, and the calibration method steps may be repeated for each LED included within the illumination device and upon subjecting the illumination device to a second ambient temperature.

An image capture device includes a light source, an image capture circuit, and a processor. The light source is used for generating emitting light. The image capture circuit is used for capturing an image corresponding to the emitting light. The processor is coupled to the light source and the image capture circuit for optionally adjusting the intensity of the emitting light of the light source according to luminance corresponding to the image and a target value.

An illumination device and method is provided herein for controlling individual light emitting diodes (LEDs) in an LED illumination device, so that a desired luminous flux and a desired chromaticity of the device can be maintained over time as the LEDs age. According to one embodiment, the method comprises applying drive currents to a plurality of LED chains substantially continuously to produce illumination, measuring a photocurrent induced on the photodetector in response to the illumination produced by each LED chain, one LED chain at a time, and received by the photodetector, and measuring a forward voltage developed across the photodetector by applying a non-operative drive current to the photodetector. For each LED chain, the method may further comprise determining an expected photocurrent value corresponding to the forward voltage measured across the photodetector and the drive current currently applied to the LED chain by applying one or more interpolation techniques to a table of stored calibration values correlating forward voltage and photocurrent to drive current at a plurality of different temperatures, and adjusting the drive current currently applied to the LED chain if a difference exists between the expected photocurrent value and the measured photocurrent.

An electronic device may have control circuitry and input-output components. The input-output components may include audio components, sensors, and other devices. A proximity sensor may supply the control circuitry with proximity sensor data. The control circuitry may adjust the audio components or take other suitable action in response to proximity sensor readings from the proximity sensor. The proximity sensor may have a light source such as an infrared laser diode and a light detector that measures a reflected portion of infrared light pulses emitted by the infrared laser diode. The control circuitry may include circuitry for safely producing pulses of emitted light with the light source. This circuitry may include a signal generator that produces ramped pulses, a differentiator that differentiates the ramped pulses to produce differentiated pulses, and an output driver that produces current pulses for the light source based on the differentiated pulses.

A low-voltage alternating current-based LED light with built-in cooling and automatic or manual dimming. As it is self-cooled with fan failure protection, the light can be safely run in conditions that are near-hostile to its operation, with little possibility of damage. The light is movable along the XY axes of a grid system and can be either fixed in position in the Z axis or can be movable up and down the Z axis. The light can be equipped with either manual dimming using a standard potentiometer, or with automatic dimming via sensors and local network connectivity. The device prevents line-voltage electric shocks as the input voltage is low-voltage AC; in embodiments, about the same voltage as a doorbell, and the input current is 3 A. The device is also self-cooled, and will shut down if its fan is not running so as to prevent thermal overloads.

A coupling device for an optical waveguide includes an optical waveguide connection for a first optical waveguide. The coupling device includes an optical filter arranged in a beam path between a laser light source and the optical waveguide connection which reflects light of a first wavelength range or a first polarization direction and transmits light of a second wavelength range or a second polarization direction.