Koninklijke Philips Corporation N.V.

Johannes Jacobus Franciscus Geijtenbeek

Hendrik Anton Van Esveld

Fransiscus Arnoldus Vermeulen

Johan Leopold Victorina Hendrix

Gerardus Marinus Josephus Franciscus Luijks

Vincent Fischer

Joseph Leonardus Gregorius Suijker

Theodorus Gerardus Marinus Maria Kappen

Antonius Arnoldus Duisters

Francis Jozef Clementina Vandyck

Catharina Johanna Maria Daemen

Theodorus Peterus Cornelis Maria Vos

Vital Louis Elisabeth Bruyndoncx

A metal halide lamp includes a discharge vessel surrounded by an outer envelope with clearance and has a ceramic wall which encloses a discharge space filled with a filling comprising an inert gas, such as xenon (Xe), and an ionizable salt. In the discharge space, two electrodes are arranged whose tips have a mutual interspacing so as to define a discharge path between them. The ionizable salt comprises NaI, TlI, CaIand X-iodide wherein X is selected from the group comprising rare earth metals.

Metal halide lamp

A method for driving a lamp is described includes generating a light controlling DC electric field E with a desired direction and a desired strength inside the lamp such as to obtain a desirable ion distribution inside the lamp. The lamp is supplied with a commutating current with a DC component, having a constant current intensity and a duty cycle differing from 50%. By setting the duty cycle, it is possible to set a certain average value of the lamp current, allowing the efficacy and/or color temperature of the lamp to be influenced.

Method and device for driving a metal halide lamp

A metal halide lamp () is described, the lamp being designed such that, when the lamp is operative in a vertical orientation, the location of the salt pool is close to the top of the discharge chamber (). In an embodiment, the coldest spot is close to the top of the discharge chamber. Means are provided enabling more heat to be supplied to the bottom part than to the upper part. In a lamp assembly (), comprising a lamp () arranged inside a bulb (), additional heat generating means () may comprise a radiation coil ().

Gas discharge lamp

The electric high-pressure discharge lamp has tungsten electrodes ( ) in a light-transmitting lamp vessel ( ) which is closed in a gastight manner. The electrodes ( ) comprise an emitter, preferably in the form of an inner coiled-coil ( ), which is loosely retained in a cavity ( ) of a basket ( ) of the electrode ( ). The inner coil ( ) acts as a non-oxidic emitter. The lamp retains its initial light output to a high degree throughout its life.

Electric high-pressure discharge lamp

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Eindhoven, Netherlands

Johannes Jacobus Franciscus Geijtenbeek