A first light source illuminates a first region. A second light source is configured to provide lower luminance than that of the first light source. The second light source illuminates a second region that overlaps the first region, and that has a larger area than that of the first region. A lighting circuit drives the first light source and the second light source according to a common lighting instruction. The lighting circuit gradually turns on the first light source and the second light source with different gradual changing time periods in response to the lighting instruction.

Disclosed herein is a method of optical pulse emission including three phases. During a first phase, a capacitor is charged from a supply voltage node. During a second phase, a voltage stored on the capacitor is boosted, and then the capacitor is at least partially discharged through a light emitting device. During a third phase, the capacitor is further discharged by bypassing the light emitting device. The third phase may begin prior to an end of the second phase.

Examples are disclosed that relate to monitoring an emission state of light sources. One example provides a light emitting circuit comprising a power source, one or more light sources connected to an output of the power source, and a control circuit comprising a pulsed voltage source and a control transistor configured to regulate a current through the light sources based upon an output of the pulsed voltage source. The light emitting circuit further comprises a monitor transistor comprising a gate connected to an output of the light sources such that a voltage at the output of the light sources controls an output of the monitor transistor, and a monitor transistor detector connected to the output of the monitor transistor. The monitor transistor detector is configured to monitor a state of the one or more light sources based upon a state of the output of the monitor transistor.

The present disclosure relates to a lighting arrangement, which comprises at least one light source, with at least one camera and a control system, wherein the colour and/or colour temperature of the light source is variable and the camera records images of a region illuminated by the light source. According to the disclosure, the control system controls the lighting arrangement such that the light source illuminates the illuminated region successively with light of a different colour and/or colour temperature, wherein the control system separately evaluates and/or outputs a first image recorded in a first colour and/or colour temperature of the lighting.

The present disclosure relates to a lighting arrangement, which comprises at least one light source, with at least one camera and a control system, wherein the colour and/or colour temperature of the light source is variable and the camera records images of a region illuminated by the light source. According to the disclosure, the control system controls the lighting arrangement such that the light source illuminates the illuminated region successively with light of a different colour and/or colour temperature, wherein the control system separately evaluates and/or outputs a first image recorded in a first colour and/or colour temperature of the lighting.

Embodiments of the invention provide a pulsed-output constant voltage LED driver comprising a PDM stage configured to provide power to an LED load by supplying energy at either a first or second predetermined voltage during each of a plurality of segments of a predetermined time period, wherein the number of segments during which the first voltage is supplied is correlated with the power provided to the LED, and wherein the positions within the time period of the segments during which the first voltage is applied are random. Embodiments of the invention provide a method of supplying power to an LED load using a pulsed-output constant voltage LED driver, the method comprising: varying a number of pulses provided by the pulsed-output constant voltage LED driver over a fixed period of time such that the number of pulses determines the power level provided to the LED load, wherein varying the number of pulses allows for modulation in a light output of the LED load, and wherein the temporal position of the pulses in the fixed period of time is random.

A system and method is described that enables an observer to quickly and easily identify specific and individual distributed electronic devices from a collection of dozens, or with variations up to hundreds of thousands. The solution is simultaneously active on all of the devices, is reconfigurable at any time, and only requires specifically defined colored optical patterns generated at each device to be in the observer's visual range. Implementable with a single LED display the system is easily adapted to limited space applications and incurs minimal cost.

A system and method is described that enables an observer to quickly and easily identify specific and individual distributed electronic devices from a collection of dozens, or with variations up to hundreds of thousands. The solution is simultaneously active on all of the devices, is reconfigurable at any time, and only requires specifically defined colored optical patterns generated at each device to be in the observer's visual range. Implementable with a single LED display the system is easily adapted to limited space applications and incurs minimal cost.

A Portable Network-Connected Signaling and Reporting Device that attaches to a portable power source. includes a potentiometer that controls the pulse width modulation/strobing of the at least one LED. The device includes but not limited to aluminum and plastic housing with a substantially cylindrical exterior profile for attachment to a power source. At least one electrical connection from the circuit and the power source is embedded in the housing and exposed for connection to an external charging source. The Portable Network-Connected Signaling and Reporting Device permits at least 1 electrical slot for external sensors. The external sensors can be attached to the body of the Portable Network-Connected Signaling and Reporting Device.

A system is provided for illuminating the face of an occupant for a video call in a car. At least one light source has a main light emission direction (A) which is directed toward the face of the occupant. The system also includes a camera provided to record the face of the occupant. The system controls the light source in such a way to obtain a flickering free recording of the face of the occupant.