Koninklijke Philips Corporation N.v.

Lumileds LLC

Lumileds Holding B.v.

Christoph Martiny

Matthias Wendt

Peter Josef Schmidt

Volkmar Schulz

Hans-Helmut Bechtel

Bernd Ackermann

Rainer Pietig

Matthias Heidemann

Harald Josef Günther Radermacher

Reinhold Elferich

Dirk Hente

Eduard Johannes Meijer

Georg Sauerlaender

Wolfgang Schnick

Marc Salsbury

Oliver Steigelmann

Cora Sieglinde Hecht

Peter Vergeer

Christian Maak

Embodiments of the invention are directed to a luminescent ceramic including a first phase and a second phase. The first phase is RAMSiAlNO. R is selected from the group comprising trivalent La, Gd, Tb, Y, Lu; A is selected from the group comprising bivalent Ca, Mg, Sr, Ba, and Eu; and M is selected from the group comprising trivalent Ce, Pr and Sm. The second phase may be or comprise, for example, REASiNOand RESiN, wherein RE is at least one rare-earth element selected from the group consisting of La, Gd, Lu, Y, Ce and Sc and wherein A is at least one metal element selected from the group consisting of Ba, Sr, Ca, Mg, Zn and Eu.

Luminescent materials

Embodiments of the invention include a luminescent ceramic including (BaSr)SiON:Eu258 phase wavelength converting material (0.5&#x2264;x&#x2264;0.9; 0&#x2264;y&#x2264;1; 0.001&#x2264;z&#x2264;0.02) and MSiON3334 phase material (M=Ba, Sr, Eu). The MSiON3334 phase material comprises no more than 5 weight % of the material.

Wavelength converting material for a light emitting device

The invention provides a lighting device configured to provide red lighting device light, the lighting device comprising: (i) a first light source configured to provide first light source light having a peak wavelength (&#x3bb;ls); (ii) a first red luminescent material configured to absorb at least part of the first light source light and to convert into first red luminescent material light having a first red emission peak wavelength (&#x3bb;m1), the first red luminescent material having an excitation maximum (&#x3bb;x1); (iii) a second red luminescent material configured to absorb at least part of the first light source light and to convert into second red luminescent material light having a second red emission peak wavelength (&#x3bb;m2), the second red luminescent material having a second excitation maximum (&#x3bb;x2); and wherein the first luminescent material and the second luminescent material are Eu2+ based, and wherein &#x3bb;m1&#x3c;&#x3bb;m2, &#x3bb;x1&#x3c;&#x3bb;ls and &#x3bb;x2&#x3e;&#x3bb;ls.

Phosphor converted LED with temperature stable flux and saturated red color point

The invention relates to a photo-detector comprising a light sensitive element () and a wavelength converter () arranged in front of the light sensitive element, the wavelength converter being configured to convert light of a first wavelength into light of a second wavelength and to direct the light of the second wavelength to the light sensitive element. The advantage is that a stable reading across the entire visible spectrum may be provided.

Photo-detector with wavelength converter

According to an exemplary embodiment of the present invention, a lighting system for communication with a remote control device is provided, which comprises a light emitting element adapted for emitting modulated light to the remote control and for detecting control signals from the remote control. This may provide for a communication between the remote control and the lighting system without the need of an extra sensor or an extra transmitter.

Intrinsic flux sensing

In a circuit () for sensing a property of light there are provided a first circuit element () that is sensitive to light and that is realized to generate an output signal (I) during a measurement time period (&#x394;tM), wherein the output signal (I) is generated according to light to which the first circuit element () is exposed and the temperature (T) of the first circuit element (), and a second circuit element () that is realized to increase the temperature (T) of the first circuit element () during a warming time period (&#x394;tW) that precedes the measurement time period (&#x394;tM).

Circuit for and a method of sensing a property of light

Light sensors () are used in lighting applications, especially in combination with LEDs, to control and/or adapt the color point of light sources. Costs and/or performance of the light sensor () are essential in order to guarantee cost-effective light sources with reproducible color points. This aim is achieved by a light sensor () comprising a light diffuser (), an optical non-transparent housing () having at least one window (), at least one interference filter () and at least two photo sensors (). The light diffuser () is arranged in such a way that light from outside the optical non-transparent housing () has to pass the light diffuser () so as to enter the interior of the optical non-transparent housing () via the window (). The interference filter () and the at least two photo sensors () are arranged in the interior of the optical non-transparent housing (), which interference filter () is arranged between the window () and the at least two photo sensors ().

Light sensor and lighting device with adaptable color

An x-ray tube disclosed here in includes an emitter arranged to emit electrons on to a focal spot on a rotatable anode. The x-ray tube also includes a hollow tube arranged to receive electromagnetic radiation from the focal spot at one end of the hollow tube and transmit it to another end. The x-ray tube also includes two or more sensors arranged to detect the electromagnetic radiation through the hollow tube.

Dual-color pyrometric measurement of X-ray focal spot temperature

The invention relates to an illumination device () with a number of light emitters, for example LEDs (L, L, L, L) of individual emission spectra. Sensor units (D, D, D, D) can produce a vector of measurement signals (S, S, S, S) that represent the light output of a single active light emitter. Based on a linear relation obtained during a calibration procedure, a characteristic value of the light output of that light emitter (L, L, L, L) is then calculated from the measurement vector, wherein said characteristic value is based on the coefficients of a decomposition of the individual emission spectrum into basis functions.

Supervision of an illumination device

A driver circuit for operating one or more light emitting diodes(LEDs) is disclosed. An alternating supply current is generated and transformed to an alternating secondary winding voltage. Using rectifier means, such as diodes or synchronous switches, the alternating secondary winding voltage is converted to a substantially constant load current by using a buffer element. The buffer element comprises an output choke, such as an inductor. The power transferred from the power source to the LEDs may be controlled by frequency control of the alternating supply current.

Method and a driver circuit for LED operation

Dual-colour pyrometric measurement of X-ray focal spot temperature

A lighting device, and a lighting system including such a lighting device and an adjustable power source, includes at least one LED, a control device employing a device for measuring a quantity that is indicative of an electrical resistance of the LED at a predetermined current or voltage, a power supply control device for controlling an adjustable electrical power supply for driving the LED. The electrical resistance of a LED is functionally dependent of the LED's junction temperature, which in turn determines its optical output characteristics. Thus, by measuring the junction temperature indirectly, through measuring of electrical LED characteristics, and mapping them to a temperature, LED output control is possible.

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Aachen, Germany

Christoph Martiny