Lumileds LLC

Koninklijke Philips Corporation N.v.

Wouter Anthon Soer

Hans-Helmut Bechtel

Rene P Helbing

Yifeng Qiu

Zhihua Song

Guan Huang

Ron Bonne

Oleg Borisovich Shchekin

Olexandr Valentynovych Vdovin

Hendrik Johannes Boudewijn Jagt

Zhi Hua Song

Willem Sillevis-Smitt

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.

Lighting system having reduced melanopic spectral content

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.

Tapped single-stage buck converter LED driver

Light modules and methods of forming light modules are disclosed. A light module includes a first plurality and a second plurality of light emitting elements configured to emit, respectively, a first light and a second light, and both arranged on a substrate. An encapsulation layer is disposed over the first and second plurality of the light emitting elements, and a wavelength converting element is dispersed in the encapsulation layer. A concentration of the wavelength converting element in the encapsulation layer varies, is larger over the first plurality of light emitting elements and is smaller over the second plurality of light emitting elements.

Hybrid chip-on-board LED module with patterned encapsulation

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.

Dimming LED circuit augmenting DC/DC controller integrated circuit

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.

Printed circuit board for integrated LED driver

A light emitting device is disclosed and includes an emission source configured to emit a primary blue light and a wavelength-converting element configured to convert the primary blue light to a secondary light having a correlated color temperature (CCT) in the range of 1600K-2500K and color rendering index (CRI) in the range of 40-60, the wavelength-converting element including a red phosphor material having a peak emission wavelength that is less than 620 nm and a green phosphor material having a peak emission wavelength that is greater than 530 nm. The device may exhibit a melanopic/photopic ratio of less than 0.25 and/or may exhibit a radiometric power fraction of light having a wavelength below 530 nm below 0.1.

Light emitting device with improved warm-white color point

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.

Lighting system with integrated sensor

Different wavelength conversion materials, or different concentrations of a wavelength conversion material are used to encapsulate the light emitting elements of different colors of a hybrid light emitting module. In an embodiment of this invention, the light emitting elements of a particular color are encapsulated with a transparent encapsulant, while the light emitting elements of a different color are encapsulated with a wavelength conversion encapsulant. In another embodiment of this invention, a particular set of light emitting elements of different colors is encapsulated with a different encapsulant than another set of light emitting elements.

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.

Different wavelength conversion materials, or different concentrations of a wavelength conversion material are used to encapsulate the light emitting elements of different colors of a hybrid light emitting module. In an embodiment of this invention, second light emitting elements () of a particular color are encapsulated with a transparent second encapsulant (), while first light emitting elements () of a different color are encapsulated with a wavelength conversion first encapsulant (). In another embodiment of this invention, a particular second set of second and third light emitting elements () of different colors is encapsulated with a different encapsulant than another first set of first light emitting elements ().

The generally Lambertian LED die emission is modified by an optical structure formed over the LED die that reduces the light emission along a normal axis and enhances the light emission at an angle with respect to the normal axis, producing a certain light emission profile. A phosphor layer is provided overlying the optical structure, such as in a reflective light-mixing chamber. The light emission profile results in more uniform flux from the LED die impinging across the surface of the phosphor. Some of the LED light passes through the phosphor and some of the light is converted to light of a different wavelength. The light emission profile results in more uniform color and temperature across the phosphor. The light emission profile may be created by a lens, a patterned layer over the LED die, a semi-reflective layer over the LED die, an optical sheet, or other technique.

Growing community of inventors

San Jose, CA, United States of America

Wouter Anthon Soer