Philips

About: Philips is a company organization based out in Vantaa, Finland. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 68260 authors who have published 99663 publications receiving 1882329 citations. The organization is also known as: Koninklijke Philips Electronics N.V. & Royal Philips Electronics.

LED luminaire with electronically adjusted color balance

Abstract: A luminaire comprises an array of LEDs that include at least one LED in each of a plurality of colors. Supplied to the LEDs for each color is an electrical current that, during a measuring period, comprises a measuring drive pulse having at least a first boost portion and a turn-off portion. The LEDs relating to each color have a light output which has a nominal continuous value during ordinary operation and increases during the boost portion and is interrupted during the turn-off portion. The array has a combined light output when current is supplied to all of the LEDs in the array. A photodiode is arranged to measure the combined light output which selectively turning off the electrical current to the LEDs so that the photodiode measures the light output for each color separately in response to the measuring drive pulse. The average light output during the measuring period is substantially equal to the nominal continuous light output during the ordinary operation so as to avoid visible flickers.

White light-emitting diode

Abstract: The invention relates to a light-emitting device comprising a UV diode with a primary emission of 300 nm ≤ μ ≤ 370 nm,and a phosphor layer consisting of a combination of a blue-light emitting phosphor with an emission band of 430 nm ≤ μ ≤ 490 nm, a green-light emitting phosphor with an emission band of 520 nm ≤ μ ≤ 570 nm and a red-light emitting phosphor with an emission band of 590 nm ≤ μ ≤ 630 nm, said device emitting high-quality white light. The colour rendering index CRI is 90 at a colour temperature of 4 000 K. As colour rendering depends only on the composition of the three phosphors and not on the relation of converted to non-converted light it is easyto control and regulate.

Transistor matching in analog CMOS applications

Abstract: This paper gives an overview of MOSFET mismatch effects that form a performance/yield limitation for many designs. After a general description of (mis)matching, a comparison over past and future process generations is presented. The application of the matching model in CAD and analog circuit design is discussed. Mismatch effects gain importance as critical dimensions and CMOS power supply voltages decrease.

Large remanent polarization of (Bi, Nd)4Ti3O12 epitaxial thin films grown by metalorganic chemical vapor deposition

Abstract: (104)-oriented Bi4Ti3O12, La-substituted Bi4Ti3O12[(Bi3.44La0.56)Ti3O12] and Nd-substituted Bi4Ti3O12[(Bi3.54Nd0.46)Ti3O12] films were epitaxially grown on (111)SrRuO3//(111)SrTiO3 substrates at 700 °C by metalorganic chemical vapor deposition. All deposited films showed strong (104) orientations. The values of the remanent polarization (Pr) and coercive field (Ec) of the (104)-oriented epitaxial (Bi3.54Nd0.46)Ti3O12 thin film were 25 μC/cm2 and 135 kV/cm, respectively. This Pr value was larger than that of the (104)-oriented (Bi3.44La0.56)Ti3O12 film: Pr and Ec values of the (Bi3.44La0.56)Ti3O12 were 17 μC/cm2 and 145 kV/cm, respectively. These good ferroelectric properties of (Bi3.54Nd0.46)Ti3O12 films can be explained by a large tilting of TiO6 octahedra induced by the substitution of Nd3+, the ionic radius of which is smaller than that of La3+. Moreover, this Pr value is almost equal to that of commercially used lead zirconate titanate (PZT) films for nonvolatile ferroelectric random access memory (Fe...

Polynomial time algorithms for network information flow

Abstract: The famous max-flow min-cut theorem states that a source node s can send information through a network (V,E) to a sink node t at a data rate determined by the min-cut separating s and t. Recently it has been shown that this rate can also be achieved for multicasting to several sinks provided that the intermediate nodes are allowed to reencode the information they receive. In contrast, we present graphs where without coding the rate must be a factor Ω(log|V|) smaller. However, so far no fast algorithms for constructing appropriate coding schemes were known. Our main result are polynomial time algorithms for constructing coding schemes for multicasting at the maximal data rate.