Abstract: A flat fluorescent lamp (1) has a discharge vessel (2) having a base plate (7), a top plate (8) and a frame (9) which are connected to one another in a gas-tight fashion by means of solder (10). Structures resembling conductor tracks function in the interior of the discharge vessel as electrodes (3-6), in the feedthrough region as feedthroughs, and in the external region as external supply leads (13; 14). Flat lamps of the most different sizes can thereby be produced simply in engineering terms and in a fashion capable of effective automation. Moreover, virtually any electrode shapes can be realized, in particular optimized with regard to a uniform luminous density with a reduced drop in luminous density towards the edges of the flat lamp. At least the anodes (5, 6) are covered in each case with a dielectric layer (15). The lamp (1) is preferably operated by means of a pulsed voltage source and serves as background lighting for LCDs, for example in monitors or driver information displays.

Abstract: A dielectric barrier discharge lamp having a cap (2), an elongate discharge vessel (1) and strip-like outer electrodes (5a-5f) has a corresponding contact spring (7a-7f) for each outer electrode. These contact springs are arranged in the interior of the cap. The cap also includes a cap sleeve (6), which surrounds one end of the discharge vessel (1) in such a manner that the or each strip-like outer electrode (5a-5f) is in electrically conductive contact with the or a corresponding contact spring (7a-7f). Preferably, the transverse extent of the individual contact springs, at least in the region of the contact, is less than or equal to the width of the corresponding strip-like outer electrode. This design combines ease of installation of the cap with a reliable contact and a high lamp efficiency.

Abstract: The invention relates to a low-pressure discharge lamp, having a tubular discharge vessel made from glass, the free ends of which are closed off in a gas tight manner, two electrode systems (3) each having a filament (7), two supply conductors (5, 6) and a bead (8) of glass, the ends of the supply conductors (5, 6) being fused into the ends of the discharge vessel which have been closed off in a gas tight manner and, in order to be held in a region between the filament (7) and the discharge vessel fused seal (2), into the bead (8), and a device for switching off the lamp at the end of its service life, comprising a paste (9) which contains a metal hydride and is fitted to the bead (8). According to the invention, the bead (8) consists of a glass material which has a resistivity of greater 108 ?cm at 350° C.

Abstract: A novel method for producing discharge lamps, in which discharge vessels 5 are filled in a chamber 4 with the required gas filling at normal pressure.

Abstract: An electrical device such as a ballast for fluorescent lamps and including a housing, a terminal, and a catch element for connecting the terminal to the housing, the catch element including a catch leg for connecting the terminal to the catch element and for connecting the catch element to the housing. Accordingly, the electrical device is designed such that the individual terminal sites of the terminal have minimal positional tolerance so that the terminal can be wired with an automatic installation machine without the danger of misinsertions.

Abstract: The discharge volume has an internal length L and a maximum diameter D at its center, with the discharge vessel being equipped with a light-emitting filling and with two electrodes at the ends of the discharge vessel, with the lamp being operated by means of high frequency such that an acoustic longitudinal mode is formed, with the wall thickness varying along the length L of the discharge volume, with the wall thickness S being thinnest at the center of the discharge vessel, while it is at least 1.2 S at an optimum point Popt, with the optimum point in each case being at a distance of {fraction (7/24)} L from the end of the discharge vessel.

Abstract: The planar light source (1) uses the principle of RGB mixing, the radiation of UV diodes (5) arranged in a planar fashion being converted by means of phosphors (7) which emit in the red and green spectral regions. The blue component is added by blue-emitting LEDs (8) whose radiation is preferably launched as a lateral diode row (9).

Abstract: The phosphor composition for low-pressure gas discharge lamps with a high light efficiency for generating radiation with a color temperature of greater than 5000 K and a very good general color rendering index Ra of greater than 90 includes at least one halophosphate phosphor, a phosphor which emits in the red wavelength region and a phosphor which emits in the blue-green wavelength region. In addition, according to the invention the phosphor composition contains an Eu-doped barium magnesium aluminate phosphor BaMgAl10O17:Eu and a Tb-doped green-emitting phosphor.

Abstract: In a lighting system which includes an electronic operating device and a gas discharge lamp with filaments, one filament terminal is respectively connected to an impedance network. The impedance network has an impedance function with a zero point at the frequency f1. For preheating purposes, the electronic operating device outputs a voltage whose frequency is close to the frequency f1. As a result, the voltage across the lamp is below the non-starting voltage during preheating.

Abstract: A rectifier circuit matched for power factor correction. A first diode (D1), a second diode (D2), a third diode (D3) and a fourth diode (D4) are in a bridge arrangement. A first pole (10) and a second pole (12) of the bridge arrangement are connected to a source (U) which has at least one AC voltage component. An inductance (L1) is arranged in series with the third pole (14) or the fourth pole (16) of the bridge arrangement. A capacitance (C1) is connected between the first pole (10) and the second pole (12), and two of the four diodes (D1, D2, D3, D4) are in the form of fast diodes.

Abstract: Disconnection device for an electronic operating device for gas discharge lamps. The filament breakage of a lamp is evaluated by detecting the current through a component which flows through the filaments. This is performed either by detecting this current with the aid of an optocoupler or by measuring the phase of the load circuit current.

Abstract: A dielectric barrier discharge lamp has elongated electrodes (3) that are arranged on the inside of the wall of the discharge vessel (2) and are covered by a dielectric layer (4). Arranged on the outside of the wall of the discharge vessel (2) is an electrically conductive means (8) that is limited with reference to the longitudinal axis to a subregion (B) of the discharge vessel wall, for example a metal ring. The startability of the dielectric barrier discharge lamp when first being started or after long operational pauses is improved thereby.

Abstract: The invention relates to a ballast for a lamp having an inverter which includes at least one switch (S1; S2), and having a drive circuit (10) for alternately opening and closing the at least one switch (S1; S2) wherein the drive circuit (10) is designed to drive the at least one switch (S1; S2) alternately at at least two different frequencies (&ohgr;a, &ohgr;b). It also relates to a method for operating a ballast for a lamp having an inverter which comprises at least one switch (S1; S2), and having a drive circuit (10) for alternately opening and closing the at least one switch (S1; S2) wherein the drive circuit drives the at least one switch (S1; S2) alternately at at least two different frequencies (&ohgr;a, &ohgr;b).

Abstract: In the case of a quiet discharge lamp, support elements for supporting a top plate are provided, by comparison with a base plate, in larger numbers and in an alternating arrangement with individual discharge structures.

Abstract: Illumination device with at least one LED as light source, the LED emitting primary radiation in the range from 380 to 420 nm, this radiation being partially or completely converted into longer-wave radiation by phosphors which are exposed to the primary radiation from the LED, the conversion taking place at least with the aid of a phosphor which emits over a broad band and originates from the class of the (Eu,Mn)-coactivated halophosphates, the cation M representing one of the metals Sr, Ca, Ba.

Abstract: A novel operating circuit for a low-pressure gas discharge lamp 1 in the case of which a digital controller 12 is designed such that by gradually lowering the operating frequency in the ignition procedure it initiates shutdown operations of a safety shutdown device for excessive currents through a lamp inductor 10 in order thereafter to increase the operating frequency somewhat. It is possible overall in this way to achieve an ignition, for example by repeated pulsed ignition operations as far as shutdown operations, or else by a continuous ignition operation at a minimum frequency at which no shutdown operation occurs. The invention has the advantage of being insensitive to temperature fluctuations and component tolerances and, moreover, of permitting the lamp inductor 10 to have comparatively small dimensions.

Abstract: An operating circuit for a discharge lamp (LP) having preheatable electrodes includes a device (C14, T11, T12, T13, G) for preheating the electrodes. The device includes a resonant circuit (C14, T11) which oscillates during preheating. During operation, the operating circuit produces an AC voltage having a frequency that is moved through a frequency range, records the response of the resonant circuit (C14, T11) by measuring an electrical variable (UC14), and identifies the resonant frequency of the resonant circuit (C14, T11) from the electrical variable (UC14), and preheats the electrodes by setting the frequency of the AC voltage to the resonant frequency.

Abstract: The present invention relates to a device for preheating the two coil electrodes (W1, W2) of a fluorescent lamp (La) comprising an AC voltage source (10), a resonance capacitor CR, which is arranged serially between the two coil electrodes (W1, W2), a first inductance (L1), which is coupled between the AC voltage source (10) and one of the two coil electrodes (W1, W2), and a second inductance (L2), which is connected to a point between the AC voltage source (10) and the coil electrode (W1) coupled thereto, the second inductance (L2) being coupled to the first inductance (L1) in such a way that a current flow (IL2) through the second inductance (L2) leads to a reduction of the magnetization of the first inductance (L1). It furthermore relates to a corresponding method.

Abstract: The invention relates to a novel operating circuit for a discharge lamp, in the case of which the lamp electrodes are preheated by driving switching transistors of an oscillator circuit such that their frequencies are detuned with reference to the resonant frequency of the lamp circuit. The drive frequency is defined by an independent resonant circuit.

Abstract: A free-running circuit arrangement for operating a load, has at least one switching element, a freewheeling diode connected in an anti-parallel fashion relative to the main current direction of the at least one switching element, a load circuit and a control resonant circuit which comprises at least one control inductor and at least one self-capacitance of the at least one switching element. The at least one switching element has a control electrode, a working electrode and a reference electrode, a capacitance acting between the control and working electrodes that is coupled to the control resonant circuit such that energy is fed into the control resonant circuit by the charging and discharging current of this capacitance, the circuit arrangement having no components for feeding energy into the control resonant circuit by electromagnetic coupling.