U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Horst Dannert

Bernd Rausenberger

Albrecht Kraus

Wilhelm A Groen

Hans-Peter Stormberg

Hans-Jurgen Hirsch

Ralf Schafer

Dieter Leers

Klaus B Lohn

Martin Ossmann

Hans-Gunther Ganser

Claus Beneking

Manfred Neiger

Hans J Hirsch

Klaus Stockwald

Volker Schorpp

Ewald Klein

Karl-Heinz Panstruga

The invention relates to a low-pressure gas discharge lamp which includes at least one discharge vessel and at least two capacitive coupling-in structures and operates at an operating frequency f. In order to achieve a better efficiency in combination with a small structural volume, a high luminous flux, a low operating voltage, a low electromagnetic emission, a high resistance against switching transients and a long service life for the low-pressure gas discharge lamp, it is proposed to form each capacitive coupling-in structure from at least one dielectric having a thickness d and a dielectric constant &#x2208;, each dielectric being subject to the condition d/(f.&#x2208;)&#x3c;10cm&#xb7;s. A substantially larger amount of light can thus be generated per lamp length (lumen/cm).

Device for the backlighting of a liquid crystal display that includes at least one low-pressure gas discharge lamp

The invention relates to a low-pressure gas discharge lamp which includes at least one discharge vessel and at least two capacitive coupling-in structures and operates at an operating frequency f. In order to achieve a better efficiency in combination with a small structural volume, a high luminous flux, a low operating voltage, a low electromagnetic emission, a high resistance against switching transients and a long service life for the low-pressure gas discharge lamp, it is proposed to form each capacitive coupling-in structure from at least one dielectric having a thickness d and a dielectric constant &#x3b5;, each dielectric being subject to the condition d/(f.&#x3b5;)&#x3c;10cm.s. A substantially larger amount of light can thus be generated per lamp length (lumen/cm).

Low-pressure gas discharge lamp

The invention relates to a gas discharge lamp with a gas discharge vessel filled with a filling gas with a filling gas pressure p and at least one capacitive excitation structure. To improve the luminous efficacy of the gas discharge lamp, it is suggested that an electrode of a dielectric material forms at least one capacitive excitation structure, which electrode is connected to the gas discharge vessel and encloses at least one hollow space with a surface area A and a volume V, for which it is true that p&middot;V/A<10 cmTorr. Such a dielectric or capacitive electrode, according to the invention, is shaped such that it has a hollow space which is closed off in a vacuumtight manner except for a communication to the gas discharge vessel. It has a surface area A on the inside of the electrode and surrounds a volume V. The dimensions of the hollow space are such that p&middot;V/A<10 cmTorr, the filling gas pressure p being given in Torr.

Gas discharge lamp with a capactive excitation structure

A gas discharge lamp has at least one capacitive electrode of a dielectric material having a dielectric saturation polarization P and an effective surface A wherein the product of P&middot;A>10 C. This lamp can be operated without drive electronics or a ballast, using power available at private households.

Gas discharge lamp

The discharge lamp comprises a piezotransformer and at least one of the lamp electrodes comprises a secondary side of the piezotransformer. Since the piezotransformer functions as a lamp electrode, as a ballast choke and as a transformer, the discharge lamp can be operated by means of a relatively simple and cheap ballast circuit.

Discharge lamp

A high-pressure glow discharge lamp (1) having a planar discharge vessel (2) which is sealed in a vacuumtight manner, which surrounds a discharge space (3) filled with a gas mixture which forms excimers, and whose parallel walls (4, 5) are formed from a dielectric material. The surfaces (6, 7) of the walls (4, 5) remote from the discharge space (3) are provided with planar electrodes (8, 9). At least one (5) of these walls with its associated electrode (8) is at least partly transparent to the generated radiation. The gas mixture includes at least one of the rare gases Xe, Kr and Ar for forming an excimer and at least one of the halogens I.sub.2, Br.sub.2, Cl.sub.2 and F.sub.2. The partial pressure of the substance forming the excimer is at least 10 and at most 600 mbar in the case of Xe and/or Kr and at least 10 and at most 1000 mbar in the case of Ar. The partial pressure of the halogen is between 0.05 and 5% of the partial pressure of the substance forming the excimer. The atomic mass of the substance forming the excimer is greater than the atomic mass of the halogen. The lamp has a high radiant efficacy and can be constructed as a large-area, homogeneously emitting radiant source.

High-pressure glow discharge lamp

In a high-pressure gas discharge lamp having a discharge vessel containing an ionizable gas filling, consisting of translucent material and surrounded by a translucent outer envelope, which is adjoined at an end thereof by a lamp cap, the space between the discharge vessel and the said end of the outer envelope accomodates a thermally insulating porous translucent element consisting of a microporous aerogel.

High-pressure discharge lamp having a thermal insulating member

A circuit arrangement for igniting and operating gas discharge lamps comprises a choke coil (1) connected between a lamp (2) and an a.c. supply source. The choke coil has an inductance L and an ignition device (3) is connected to the lamp. A capacitor (9) having a capacitance C is connected in parallel with at least a part of the choke coil in order to pass an ignition current to the lamp that is higher than the normal lamp operating current. The relationship betweeen the capacitive reactance of the capacitor and the inductive reactance of the choke coil is 1/.omega.C&gt;3.omega.L.

Circuit arrangement for igniting and operating gas discharge lamps

Electrostatic charge images of identical shape but opposite sign are generated on both sides of a transparent, highly insulating foil. Subsequently, pigment is deposited on both sides of the foil by means of oppositely charged developers. The optical density of an electrophotographic image on a transparent insulating foil is increased, as compared to densities achieved in the past, for a given surface charge density by establishing a charge exchange between one side of the foil and an electrode. On the other side of the foil a charge image is generated and the foil. The electrode are separated from each other prior to development.

Electrophotographic method of generating electrostatic images on two

An electroradiographic display with a high picture quality at low radiation intensities is obtained with a device consisting of a source of X-rays, an electrode passing X-rays, an intermediate recording space for an object to be displayed, an electrode on the side remote from the recording space on which a layer of dielectric material is disposed, and a second electrode with a photoconductive layer. The layers are separated by a gas gap which is bounded by one or more side walls. A direct voltage source is in electrical contact with the electrodes. The photoconductive layer comprises a granular photoconductive material in a binder. The gas gap between the dielectric layer and the photoconductive layer is from 50 to 500 .mu.m wide and the electrode passing X-rays has a surface resistance between 10.sup.3 to 10.sup.8 Ohms.

Electroradiographic recording device

The sensitivity of photoconductive layers of tetragonal lead monoxide in a binder is increased when the tetragonal lead monoxide produced by prior art process after being subjected to a further treatment has a grain size of 1 to 50 .mu.m and is dispersed in the binder without mechanical force and is sedimented on a layer carrier without mechanical force.

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Aachen, Germany

Horst Dannert