U.S. Philips Corporation

Godefridus H Heijnen

Gijsbert H Kuus

Cornelis Am Mulder

Arian Molenaar

Ernest O Van Der Stelt

The colored electric lamp has a lamp vessel (1) carrying a colored translucent interference filter (12) of alternately SiO.sub.2 layers and layers of comparatively high refractive index. In the filter, layers of high refractive index have an optical thickness smaller than 1/4.lambda..sub.0, while SiO.sub.2 layers have an optical thickness larger than 1/4.lambda..sub.0. An SiO.sub.2 layer of 500-900 nm thickness can be present on the filter. The light emitted by the lamp has a higher color saturation and the filter has a better adherence to the lamp vessel than in the case of a lamp comprising a conventional filter having an equal overall thickness of layers of high refractive index.

Filter for colored electric lamp

An electric lamp has elongated metal foils as a part of the current conductor lead-throughs. Each metal foil has major surfaces which meet one another along each opposing side edge of the foil at an acute angle. The metal foil has a cross-section transverse to the side edges. At least one of the major surfaces has a pair of concave curvature portions each adjoining a respective side edge, and a convex curvature portion extending between the pair of concave curvature portions.

Electric lamp having a metal foil with a convexly and concavely curved

A copper-plating bath suitable for reprographic uses and for making electrically conducting metal patterns with one of the redox pairs V.sup.2+ /V.sup.3+, Ti.sup.2+ /Ti.sup.3+, or Cr.sup.2+ /Cr.sup.3+ as a reducing agent, ascorbic acid with an acid acceptor, or the redox pair Fe.sup.2+ /Fe.sup.3+ together with an organic carboxylic acid and a complexing agent for cuprous ions.

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Vaals, Netherlands

Godefridus H Heijnen