Peter A. Duine

Bio: Peter A. Duine is an academic researcher from Philips. The author has contributed to research in topics: Display device & Backlight. The author has an hindex of 15, co-authored 38 publications receiving 705 citations.

Optical switches based on magnesium lanthanide alloy hydrides

Abstract: It is shown that thin layers of palladium coated magnesium lanthanide alloys reversibly go through an optical transition by variation of the hydrogen concentration, just as has recently been shown for pure lanthanides. With these layers optical switches can be constructed that exhibit three different optical states: a color-neutral transparent state at high hydrogen concentration, a nontransparent dark absorbing state at intermediate hydrogen pressures, and a highly reflective metallic state at low hydrogen pressures. The ratio in transmission between the transparent state and the reflecting state is more than 1000.

A model system for scandate cathodes

Abstract: In cathode-ray tubes, high current densities at relatively low operating temperatures can be achieved with dispenser cathodes containing scandium oxide. The surface structure and precise emission mechanism of the scandate cathode are not known. The surface layers of such a cathode consist of the four elements Sc, Ba, O, and W. We have studied Sc, Ba, and O overlayers and various combinations of these elements deposited on the W(001) surface, under ultrahigh vacuum conditions. We have performed in situ measurements of the work function changes accompanying the surface treatments, and correlate these with the observed surface structures. High resolution medium-energy ion scattering was used to determine the compositional depth distributions and the geometrical structures at this model cathode surface. Auger electron spectroscopy peak height ratios show that W(001), with all three overlayer elements present, can be considered representative for real scandate cathodes. The observed ultra-low work function of the W(001)/Sc,Ba,O model system explains the high current densities on real scandate cathodes.

Optical switching device comprising switchable hydrides

Abstract: A description is given of a switching device (1) comprising a transparent substrate (3), a switching film (5) including hydrides of gadolinium or other trivalent metal, and magnesium, covered with a palladium layer (7). By exchange of hydrogen, the switching film can be reversibly switched from a transparent state to a mirror-like state with zero transmission via an intermediate black absorbing state. The conversion between both states is reversible, and this phenomenon can be used, for example, in an optical switching element or sun roof.

Transflective display device

Abstract: Transflective display device having a transflector (10) which is switchable between a transparent state and a mirror-like state. Preferably, a metal hydride optical switch is used as the transflector.

Device for projecting a pixelated lighting pattern

Abstract: A lighting device is provided for projecting a pixelated lighting pattern to be viewed onto a surface facing said device is provided. The device comprises a plurality of independently controllable lighting units (1), each lighting unit comprising at least one light- emitting diode (3, 4, 5, 6), and a controller (7) for controlling the emission of light from said lighting units. A device according to the present invention allows ambient illumination of a surface and projection of images and patterns.

HYDROGEN IN METALS: Microstructural Aspects

Abstract: ▪ Abstract Metal-hydrogen (M-H) systems are interesting from both a theoretical and a practical point of view. M-H systems are utilized for energy-storage systems, in sensor applications, and in catalysis. These systems are often exploited as models for studying basic material properties, especially when the size of these systems is small and nonbulk-like contributions become dominant. Surfaces, nanocrystals, vacancy- and dislocation-rich materials, thin films, multilayers, and clusters as systems of major interest are addressed in this review. We show that the hydrogen solubility of M-H systems is strongly affected by the morphology and microstructure of and the stress between regions of different hydrogen concentration. For small-sized systems, surface- or interface-related sites become important and change the overall solubility as well as the phase boundaries of M-H systems. In thin films deposited on stiff substrates, compressive stresses evolve during hydrogen loading because the films are effective...

Self-contained, diode-laser-based dermatologic treatment apparatus

Abstract: A dermatologic treatment apparatus is disclosed that is cordless and sufficiently compact as to be hand-held. A self-contained housing is configured for gripping by a person's hand for cordless manipulation in a dermatologic treatment procedure. A light source and electrical circuit are contained within the housing. The circuit includes one or more batteries and an electronic control circuit for energizing the light source to produce output light pulses. A light path is within the housing including an aperture through which the output light pulses are propagated out of the housing having properties sufficient for providing efficacious treatment.

Electrostatic trapping of ammonia molecules

Abstract: The ability to cool and slow atoms with light for subsequent trapping allows investigations of the properties and interactions of the trapped atoms in unprecedented detail. By contrast, the complex structure of molecules prohibits this type of manipulation, but magnetic trapping of calcium hydride molecules thermalized in ultra-cold buffer gas and optical trapping of caesium dimers generated from ultra-cold caesium atoms have been reported. However, these methods depend on the target molecules being paramagnetic or able to form through the association of atoms amenable to laser cooling, respectively, thus restricting the range of species that can be studied. Here we describe the slowing of an adiabatically cooled beam of deuterated ammonia molecules by time-varying inhomogeneous electric fields and subsequent loading into an electrostatic trap. We are able to trap state-selected ammonia molecules with a density of 10(6) cm(-3) in a volume of 0.25 cm3 at temperatures below 0.35 K. We observe pronounced density oscillations caused by the rapid switching of the electric fields during loading of the trap. Our findings illustrate that polar molecules can be efficiently cooled and trapped, thus providing an opportunity to study collisions and collective quantum effects in a wide range of ultra-cold molecular systems.

Switchable mirrors based on nickel–magnesium films

Abstract: A new type of electrochromic mirror electrode based on reversible uptake of hydrogen in nickel magnesium alloy films is reported. Thin,magnesium-rich Ni-Mg films prepared on glass substrates by cosputtering from Ni and Mg targets are mirror-like in appearance and have low visible transmittance. Upon exposure to hydrogen gas or on reduction in alkaline electrolyte, the films take up hydrogen and become transparent. When hydrogen is removed, the mirror properties are recovered. The transition is believed to result from reversible formation of Mg2NiH4 and MgH2. A thin overlayer of palladium was found to enhance the kinetics of hydrogen insertion and extraction,and to protect the metal surface against oxidation.