Abstract: Techniques and devices are provided for sensing image data from a scene and activating primary light sources based on information sensed from the scene. Subsets of a plurality of primary light sources may be activated to emit sensing spectrum of light onto a scene. Combined image data may be sensed from the scene while the subsets of the plurality of primary light sources are activated. Reflectance information for the scene may be determined based on the combined image data and combined sensing spectra. Spectrum optimization criteria for the primary light sources may be determined based on the reference information and a desired output parameter provided by a user or determined by a controller. The plurality of primary light sources may be activated to emit a lighting spectrum based on the spectrum optimization criteria.

Abstract: A light emitting device comprises a first group of one or more LEDs each configured to emit light having a blue color point in the 1931 CIE x,y Chromaticity Diagram, a second group of one or more LEDs each configured to emit light having a cyan or yellow color point in the 1931 CIE x,y Chromaticity Diagram, and a third group of one or more LEDs each configured to emit light having a red color point in the 1931 CIE x,y Chromaticity Diagram.

Abstract: An apparatus is disclosed, comprising: a first light source having a first threshold voltage; a second light source having a second threshold voltage; a rectifier configured to receive an AC voltage as input and generate a DC voltage based on the AC voltage; a single-stage Buck converter section coupled to the rectifier, the first light source, and the second light source, the Buck converter section being configured to output a current generated based on the DC voltage towards the first light source and the second light source; and a switching circuit configured to reduce a load on the Buck converter section by periodically diverting the current away from the second light source when a magnitude of the AC voltage is less than or equal to a sum of the first threshold voltage and the second threshold voltage.

Abstract: Systems, devices and methods are described herein. An integrated light emitting diode (LED) lighting system includes an electronics board. An alternating current (AC) input is disposed on the electronics board. Multiple strings of LED devices are disposed on the electronics board, each having an individual voltage threshold. A buck converter is disposed on the electronics board and is electrically coupled to provide a direct current (DC) current based on an AC current at the AC input. A switching circuit is disposed on the electronics board and is electrically coupled to the strings of LED devices to apply the DC current to each of the strings in a sequence beginning at a time when an instantaneous voltage level at the AC input reaches the individual threshold voltage of a first one of the strings of LED devices in the sequence.

Abstract: A disclosed light-emitting device may provide white light with a cyan gap coinciding with a melanopic sensitivity range and thus having reduced melanopic content. The disclosed light-emitting device may include a light source providing violet or blue light with a peak wavelength under 450 nanometers (nm). The disclosed light-emitting device may include at least one down-converter coupled to and located downstream of the light source and configured with a long-wavelength onset to convert the spectrum of the violet or blue light to generate white light with a spectral power content in a 447-531 nm wavelength range that is less than or equal to 10% of a total spectral power content in a 380-780 nm wavelength range. The disclosed light-emitting device may be incorporated in a light engine system that further includes a control system that controls a drive current to the light-emitting device.

Abstract: A light emitting diode (LED) module may include a direct current (DC) voltage node formed on a first layer. The DC voltage node may be configured to sink a first current. One or more devices may be formed on the first layer configured to provide a second current to one or more LEDs. A device of the one or more devices may carry a steep slope voltage waveform. A local shielding area may be formed in a second layer directly below the DC voltage node and the one or more devices. The local shielding area may include a substantially continuous area of conductive material. A conductive via may extend through one or more layers. The conductive via may electrically connect the DC voltage node and the local shielding area.

Abstract: A multi-layer metal core printed circuit board (MCPCB) has mounted on it at least one or more heat-generating LEDs and one or more devices configured to provide current to the one or more LEDs. The one or more devices may include a device that carries a steep slope voltage waveform. Since there is typically a very thin dielectric between the patterned copper layer and the metal substrate, the steep slope voltage waveform may produce a current in the metal substrate due to AC coupling via parasitic capacitance. This AC-coupled current may produce electromagnetic interference (EMI). To reduce the EMI, a local shielding area may be formed between the metal substrate and the device carrying the steep slope voltage waveform. The local shielding area may be conductive and may be electrically connected, to a DC voltage node adjacent to the one or more devices.

Abstract: A disclosed light-emitting device may provide white light with a cyan gap coinciding with a melanopic sensitivity range and thus having reduced melanopic content. The disclosed light-emitting device may include a light source providing violet or blue light with a peak wavelength under 450 nanometers (nm). The disclosed light-emitting device may include at least one down-converter coupled to and located downstream of the light source and configured with a long-wavelength onset to convert the spectrum of the violet or blue light to generate white light with a spectral power content in a 447-531 nm wavelength range that is less than or equal to 10% of a total spectral power content in a 380-780 nm wavelength range. The disclosed light-emitting device may be incorporated in a light engine system that further includes a control system that controls a drive current to the light-emitting device.

Abstract: A disclosed light-emitting device may provide white light with a cyan gap coinciding with a melanopic sensitivity range and thus having reduced melanopic content. The disclosed light-emitting device may include a light source providing violet or blue light with a peak wavelength under 450 nanometers (nm). The disclosed light-emitting device may include at least one down-converter coupled to and located downstream of the light source and configured with a long-wavelength onset to convert the spectrum of the violet or blue light to generate white light with a spectral power content in a 447-531 nm wavelength range that is less than or equal to 10% of a total spectral power content in a 380-780 nm wavelength range. The disclosed light-emitting device may be incorporated in a light engine system that further includes a control system that controls a drive current to the light-emitting device.

Abstract: Embodiments include systems, methods, and apparatuses for providing a dimming function in a single stage AC input light emitting diode (LED) driver with a controller that contains an on-chip error amplifier and an on-chip fixed reference voltage source coupled to a first input of the error amplifier. The controller controls a duty cycle of a switching transistor to cause a feedback voltage, applied to a first package input terminal, to match the reference voltage. To achieve a dimming function, a voltage across a current sense resistor in series with the LEDs is applied to a first input of a high gain differential amplifier, and a variable dimming control voltage is applied to a second input of the differential amplifier. The output of the differential amplifier is coupled to the first package input terminal. The differential amplifier input signals will be matched at the target LED current level.

Abstract: A multi-layer metal core printed circuit board (MCPCB) has mounted on it at least one or more heat-generating LEDs and one or more devices configured to provide current to the one or more LEDs. The one or more devices may include a device that carries a steep slope voltage waveform. Since there is typically a very thin dielectric between the patterned copper layer and the metal substrate, the steep slope voltage waveform may produce a current in the metal substrate due to AC coupling via parasitic capacitance. This AC-coupled current may produce electromagnetic interference (EMI). To reduce the EMI, a local shielding area may be formed between the metal substrate and the device carrying the steep slope voltage waveform. The local shielding area may be conductive and may be electrically connected, to a DC voltage node adjacent to the one or more devices.