Abstract:
A wavelength converter for an LED is described that comprises a substrate of monocrystalline garnet having a cubic crystal structure, a first lattice parameter and an oriented crystal face. An epitaxial layer is formed directly on the oriented crystal face of the substrate. The layer is comprised of a monocrystalline garnet phosphor having a cubic crystal structure and a second lattice parameter that is different from the first lattice parameter wherein the difference between the first lattice parameter and the second lattice parameter results in a lattice mismatch within a range of 15%. The strain induced in the phosphor layer by the lattice mismatch shifts the emission of the phosphor to longer wavelengths when a tensile strain is induced and to shorter wavelengths when a compressive strain is induced. Preferably, the wavelength converter is mounted on the light emitting surface of a blue LED to produce an LED light source.
Abstract:
Systems and methods for protecting electrical components such as light emitting diodes are described. In some embodiments, electrical components are protected from high level electrostatic discharge ("ESD") events by a circuit board that provides an intrinsic level of ESD protection. At the same time, such electrical components are protected against low level ESD events by one or more diodes that are electrically coupled thereto. The one or more diodes may be thin film diodes comprising at least one layer of p-type semiconductive material and at least one layer of n-type semiconductive material. Devices including ESD protection and methods for manufacturing such devices are also described.
Abstract:
Various implementations disclosed herein includes a method for operating lighting fixtures in horticultural applications. The method may include receiving a user input of a desired irradiance for a first color channel of one or more lighting fixtures that irradiates a plant bed, in which each of the one or more lighting fixtures comprises at least one light emitting diode (LED) array, determining, for each of the one or more lighting fixtures, a PWM setting of the first color channel such that each of the one or more lighting fixtures irradiate the plant bed at the desired irradiance based on calibration data stored in each of the one or more lighting fixtures, and applying, to each of the one or more lighting fixtures, the determined PWM setting of the first color channel.
Abstract:
There is herein described a light source that homogenizes the light produced by a large area array of forward directed LEDs (102) mounted on highly reflective substrate (106), while achieving a low-profile form factor and maintaining high efficacy. The LED light source employs a diffuser (120) comprised of two diffusing layers: a low scattering diffusing layer (118) bonded to the LEDs (102) and a high scattering diffusing layer (114) that is bonded to the low scattering diffusing layer (118). The LED light source achieves good diffuse illumination with a thin diffuser by making use of a light channeling effect between the highly reflective substrate (106) and the high backscattering from the high scattering diffusing layer (114).
Abstract:
There is herein described a method for forming a circuit board comprising: (a) obtaining a substrate of a first formable polymer material, the substrate having at least one electrical conductor on a surface; (b) laminating a coverlay of a second formable polymer material to the substrate to form a flexible circuit board wherein the at least one electrical conductor is disposed between the coverlay and the substrate, the coverlay having a plurality of holes exposing at least a portion of the at least one electrical conductor; (c) electrically connecting light emitting diodes (LEDs) to exposed portions of the at least one electrical conductor; (d) heating the circuit board while applying a force to cause the circuit board to bend and adopt a shape having arcuate cross section; (e) cooling the circuit board until the shape becomes fixed whereby a thermoformed circuit board having an arcuate cross section is formed.
Abstract:
Techniques are disclosed for designing light fixtures for flexible LED circuit boards. The flexible LED circuit boards include an array of LED packages and the surface of the flexible circuit boards is highly reflective. A flexible LED circuit board may be shaped to conform to a rigid preform and the preform may be concave, convex, corrugated, or have any other custom shape. The shape of the preform, as well as the location of the LEDs within the flexible LED circuit may determine the light distribution of the light fixture. Alternatively, the lighting fixture may have multiple rods held in place with side plates and a flexible LED circuit board may be woven between the rods. A set of hole patterns in the side plates determine the location of the rods and the rods will determine the shape of the flexible LED circuit.
Abstract:
This disclosure is directed to a system for attaching devices to flexible substrates. A device may be coupled to a flexible substrate in a manner that prevents adhesive from contacting conductive ink while the adhesive is harmful. If conductive epoxy is used to anchor conductive pads in the device to the flexible substrate, conductive epoxy may be applied beyond the edge of the device over which conductive ink may be applied to make electrical connections. Holes may also be formed in the flexible substrate allowing conductive epoxy to be exposed on a surface of the flexible substrate opposite to the device location, the conductive ink connections being made on the opposite surface. The conductive ink may also be applied directly to the conductive pads when extended beyond the device's edge. The flexible substrate may be preprinted with circuit paths, the conductive ink coupling the device to the circuit paths.
Abstract:
Described herein are methods of making electronic assemblies including a subassembly film. In some embodiments, a first subassembly is formed by placing an electronic die at a die placement location on a subassembly film. A second subassembly may be formed by placing the first subassembly at a subassembly placement position on a base layer, such that electrical contacts/traces on the first film overlap with electrical contacts/traces at a subassembly connection point on the base layer. Placement of the die on the subassembly film may be performed with automatic placement machinery that has a placement accuracy that is greater than that required to place the first subassembly on the base layer. As a result, the costly and time consuming manual inspection of die placement may be avoided.
Abstract:
In general, one embodiment of the present disclosure includes a horticulture lighting device having a plurality of LED light channels that may be selectively energized to produce a predefined light pattern. Each of the LED light channels may emit one or more wavelengths and may be pulsed at a rate that may be imperceivable to a human eye, e.g., at 120 Hz to 720 Hz. Plants may respond biochemically to light patterns that include a period of delay between pulses of light, e.g., from 500 microseconds to 5 milliseconds. The biochemical response has been shown to significantly increase plant growth, e.g., up to 100%, relative to plants grown with lighting systems that use continuous, non-pulsing light sources. Thus, aspects and embodiments disclosed herein include a horticulture device capable of emitting light patterns which introduce a predefined delay period between energizing/pulsing of LED light channels to aid photosynthesis.
Abstract:
There is herein described a tubular LED lamp that comprises a diffuser, an elongated circuit board tray (102, 202), and a rigid circuit board (130) having a plurality of light emitting diodes (LEDs). The diffuser (110) has a linear shape comprising a partial tube with a longitudinal opening along its length. The elongated circuit board tray (102, 202) comprises a polymer material and has opposed longitudinal wing-like projections (120, 220) extending along its length and a flat bottom base (116, 216) between the projections. The circuit board tray (102, 202) is attached to the diffuser (110) at a longitudinal edge of each projection (120, 220) to form a tubular lamp body and the circuit board (130) is mounted to the base of the circuit board tray (102, 202). Preferably, the LEDs mounted to the circuit board (130) are located approximately at the circumference of the tubular body when the circuit board (130) is mounted in the tray (102, 202) so that diffusion of the light emitted by the LEDs may be improved.