Linear control of RGB LED for generating ambient lighting with variable color is accomplished by using multiple linear regulators to vary LED intensity via analog dimming. Each regulator controls current through a given color LED which in turn varies the LED intensity. Given the wavelength shift of LEDs at various drive currents and perceived intensity difference to the human eye, for different colors, the current regulator response may be non-linear and unique depending upon the desired color. Further, the linear drive current regulation can be accomplished using voltage mode or current mode control. The device, system and methodology, each using RGB LEDs, can reproduce any color on the Cartesian Color Coordinate system.

A pixel unit driving circuit and a method thereof, a pixel unit and a display apparatus can improve uniformity in the brightness of an OLED panel. The pixel unit driving circuit includes a driving thin film transistor, a matching thin film transistor, a signal-erasing thin film transistor, a charging control unit, a driving control unit and a storage capacitor, wherein a gate of the driving thin film transistor is connected with a high level output terminal of a driving power supply via the charging control unit, a source thereof is connected with the high level output terminal of the driving power supply, and a drain thereof is connected with an anode of an OLED; a gate and a source of the matching thin film transistor are connected with a data line via the charging control unit, and a drain thereof is connected with a second end of the storage capacitor.

A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit comprising two MOS-gated transistors, and a control circuit. The control circuit generates first and second drive voltages for individually controlling the MOS-gated transistors, and controls the gate coupling circuit to cause the MOS-gated transistors to conduct a pulse of current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a present half cycle of the AC power source, and to allow the MOS-gated transistors to conduct at least one other pulse of current through the gate terminal after the firing time during the present half cycle.

The present invention refers to a lighting device (10) and a method of operating this lighting device (10). A lighting module (13) having a light element series connection (15) of several semiconductor light elements (14) is connected to the output (12) of a drive circuit (11). The control means (20) is provided which is configured to adapt a heating condition if a heating requirement is fulfilled. In the heating condition a heating means (26) is activated by the control means (20) to heat the lighting module. The heating requirement is fulfilled when the temperature (T) of the lighting module (13) drops down to a minimum temperature value (Tmin). In so doing an undesired increase of the forward voltage (Vf) of the light element series connection (15) can be avoided.

A status indicating light unit includes a power input terminal, an illumination circuit, comprising at least one LED, a continuous connection circuit, coupled to the illumination circuit and configured to effect a continuous power transfer from a power input terminal to the illumination circuit, a pulsed power reception circuit, coupled to the illumination circuit and configured to draw power from the power input terminal in a pulsed manner and to continuously emit power to the illumination circuit, and a mode selection switch adapted to couple the continuous connection circuit to the power input terminal in a continuous power draw mode, resulting in a continuous power draw pattern of the status indicating light unit, and adapted to couple the pulsed power reception circuit to the power input terminal in a pulsed power draw mode.

Methods, apparatus and computer-readable media for controlling a lighting unit are disclosed herein. In some embodiments, a controller may be operably coupled with one or more light sensors. The controller may, in some embodiments, be configured to receive, from the one or more light sensors, one or more signals indicative of light detected by the one or more light sensors. The controller may facilitate transition of one or more light sources of a lighting unit between first and second lighting states responsive to a determination, based on the one or more signals, that a change in a property of the light detected by the one or more light sensors satisfies a predetermined criterion, such as a threshold rate of change of the property of the detected light.

A converter circuit arrangement is provided, including a converter switch controller, a converter switch, a load circuit interface and an inductor. The converter switch controller may include a control input. The converter switch may be coupled between a first power supply potential and the control input. The inductor may be coupled between a second power supply potential and the load circuit interface. The load circuit interface may be coupled between the control input and the inductor.

Embodiments of the disclosed subject matter provide a device with a base having an opening, and a plurality of organic light emitting devices (OLEDs) disposed on a plurality of substrates and arranged in a light directing structure onto the base, where the opening of the base is a light exit aperture of light output by the plurality of OLEDs.

A Light Emitting Diode (LED) based illumination device authenticates a mobile electronics device on a lighting communications network. The mobile electronic device may request a communications link on the lighting communications network and detect modulated illumination light emitted from the LED based illumination device. The modulated light may include an optical code. The mobile electronic device may determine the optical code from the modulated illumination light and communicate an indication of the optical code to the LED based illumination device. The LED based illumination device may determine if the indication of the optical code is correct and provide, in response, a communication link to the mobile electronics device on the lighting communications network.

Product display systems are provided. The product display systems may include a product display assembly and one or more products positioned in proximity to the product display assembly. The product display assembly may include a solar cell configured to receive light and output electrical current and a wireless power transmitter configured to receive the electrical current. The product may include a wireless power receiver that cooperates with the wireless power transmitter to produce current that powers an output mechanism. The output mechanism outputs a perceptible effect such as light or sound to attract consumer attention. A related method is also provided.