A lighting device comprising first and second groups of solid state light emitters, which emit light having peak wavelength in ranges of from 430 nm to 480 nm, and first and second groups of lumiphors which emit light having dominant wavelength in the range of from 555 nm to 585 nm. In some embodiments, if current is supplied to a power line, a combination of (1) light exiting the lighting device which was emitted by the first group of emitters, and (2) light exiting the lighting device which was emitted by the first group of lumiphors would have a correlated color temperature which differs by at least 50 K from a correlated color temperature which would be emitted by a combination of (3) light exiting the lighting device which was emitted by the second group of emitters, and (4) light exiting the lighting device which was emitted by the second group of lumiphors.

Lighting device and lighting method

Light emitting diodes (LEDs) are on the verge of a breakthrough in general lighting, due to their rapidly improving efficiency. Currently, white LEDs with high color rendering are mainly based on wavelength conversion by one or more phosphor materials. This Review first describes how to quantify the quality of a light source, discussing the color rendering index (CRI) and alternative color quality indices. Then, six main criteria are identified and discussed, which should be fulfilled by a phosphor candidate to be considered for actual application in LEDs. These criteria deal with the shape and position of the emission and the excitation spectra, the thermal quenching behavior, the quantum efficiency, the chemical and thermal stability and finally with the occurrence of saturation effects. Based on these criteria, the most common dopant ions (broad-band emitting Eu 2+ , Ce 3+ and Mn 2+ , line-emitting rare earth ions,...) and host compounds (garnets, sulfides, (oxy)nitrides,...) are evaluated. Although many phosphor materials have been proposed in literature in recent years, the number of phosphors effectively fulfilling all six requirements is relatively small.

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Selecting Conversion Phosphors for White Light-Emitting Diodes

Provided is a light emitting diode (LED) manufactured by using a wafer bonding method and a method of manufacturing a LED by using a wafer bonding method. The wafer bonding method may include interposing a stress relaxation layer (33) formed of a metal between a semiconductor layer (20) and a bonding substrate (31). When the stress relaxation layer is used, stress between the bonding substrate and a growth substrate may be offset due to the flexibility of metal, and accordingly, bending or warpage of the bonding substrate may be reduced or prevented.

Light-emitting device and method of manufacturing the same

A light emitting die package includes a substrate, a reflector plate, and a lens. The substrate has traces for connecting an external electrical power source to a light emitting diode (LED) at a mounting pad. The reflector plate is coupled to the substrate and substantially surrounds the mounting pad, and includes a reflective surface to direct light from the LED in a desired direction. The lens is free to move relative to the reflector plate and is capable of being raised or lowered by the encapsulant that wets and adheres to it and is placed at an optimal distance from the LED chip(s). Heat generated by the LED during operation is drawn away from the LED by both the substrate (acting as a bottom heat sink) and the reflector plate (acting as a top heat sink).

Power surface mount light emitting die package

A forward-facing vision system for a vehicle includes a forward-facing camera disposed in a windshield electronics module attached at a windshield of the vehicle and viewing through the windshield. A control includes a processor that, responsive to processing of captured image data, detects taillights of leading vehicles during nighttime conditions and, responsive to processing of captured image data, detects lane markers on a road being traveled by the vehicle. The control, responsive to lane marker detection and a determination that the vehicle is drifting out of a traffic lane, may control a steering system of the vehicle to mitigate such drifting, with the steering system manually controllable by a driver of the vehicle irrespective of control by the control. The processor, based at least in part on detection of lane markers via processing of captured image data, determines curvature of the road being traveled by the vehicle.

Vision system for vehicle

An LED illumination apparatus according to the present invention includes at least one connector and a lighting drive circuit. The connector is connected to an insertable and removable card-type LED illumination source, which includes multiple LEDs that have been mounted on one surface of a substrate. The lighting drive circuit is electrically connected to the card-type LED illumination source by way of the connector. The card-type LED illumination source preferably includes a metal base substrate and the multiple LEDs that have been mounted on one surface of the metal base substrate. The back surface of the metal base substrate, including no LEDs thereon, thermally contacts with a portion of the illumination apparatus. A feeder terminal to be electrically connected to the connector is provided on the surface of the metal base substrate on which the LEDs are provided.

LED illumination apparatus and card-type LED illumination source

An LED illumination light source comprising a substrate (11), a group of a plurality of LED elements arranged two-dimensionally on the substrate (11), and phosphor resin parts (13a, 13b) covering the plurality of LED elements respectively. Respective phosphor resin parts (13a, 13b) have a phosphor for converting a light emitted from the LED element into a light having a longer wavelength. The phosphor resin parts (13b) covering respective LED elements located in the outer circumferential region of the group are larger in size than the phosphor resin parts (13a) covering respective LED elements located in the region other than the outer circumferential region.

Led illumination light source

An LED illumination apparatus includes at least one connector and a lighting drive circuit. The connector is connected to an insertable and removable card-type LED illumination source, which includes multiple LEDs that have been mounted on one surface of a substrate. The lighting drive circuit is electrically connected to the card-type LED illumination source by way of the connector. The card-type LED illumination source preferably includes a metal base substrate and the multiple LEDs that have been mounted on one surface of the metal base substrate. The back surface of the metal base substrate, including no LEDs thereon, thermally contacts with a portion of the illumination apparatus. A feeder terminal to be electrically connected to the connector is provided on the surface of the metal base substrate on which the LEDs are provided.

Card type led illumination source

“Visual clarity” or “feeling of contrast” of object colors under illumination is affected significantly by changing color-rendering property of light source used. Though the feeling of contrast is considered one of the most important characteristics on color-rendering properties of light sources, it cannot be estimated adequately by using the present Ra method. The new index FCI is proposed for estimating the effect of feeling of contrast quantitatively under any light sources. The FCI is derived using a simple transformation of the gamut area, which is constituted by a specially selected four-color combination in CIE LAB color space. The FCI correlates well with the illuminance ratio for equal feeling of contrast (or equal visual clarity) on various light sources reported so far. Using the FCI together with the present CIE Ra, the color-rendering capability of a light source can be well clarified. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 361–371, 2007

New method for specifying color‐rendering properties of light sources based on feeling of contrast

An LED illumination light source comprising at least one LED chip (12) mounted on a substrate (11), a phosphor resin part (13) covering the LED chip (12), a lens (22) acting on light coming out from the phosphor resin part (13), and a light diffusion layer (a light-transmitting resin part (20)) having light scattering particles dispersed therein and interposed between the phosphor resin part (13) and the lens (22).

Tadashi Yano

Papers

LED illumination apparatus and card-type LED illumination source

Led illumination light source

Card type led illumination source

New method for specifying color‐rendering properties of light sources based on feeling of contrast

Method for fabricating led illumination light source and led illumination light source