Abstract:
A meander-shaped low-pressure mercury discharge lamp with cold electrodes (7, 8), in particular for use in an illumination panel for a liquid crystal display. The geometry of the tubular lamp vessel (1) bent into a meander shape is so chosen, for obtaining a good homogeneity of the luminance and a high luminous efficacy, that the length of the discharge path is between 250 and 1000 times the internal diameter of the lamp vessel (1). The internal diameter of the lamp vessel (1) preferably has a value of between 2.0 and 3.5 mm.
Abstract:
Composite sintered electrodes with improved properties that make them suitable for use in a variety of lamp types, are provided which comprise a refractory metal and a substantial amount of a refractory emitter oxide, either single layer or multiple layer, the composites having been subjected to sintering at an elevated temperature effective to form a composite electrode having a density of at least 85%, preferably in the presence of a sintering activator, such as for example, Ni, or mixture thereof with a sintering aid such as, for example, Li.sub.2 O.
Abstract:
A power supply for a cold cathode tube has a high voltage module coupled directly to the cold cathode tube, and a power control module that provides a power control signal to the high voltage module via low voltage wiring. The power control module has a circuit that compensates for negative resistance of the ionized gas within the cold cathode tube by adjusting a frequency of the power control signal. The power control module also receives a return of from the cold cathode tube, and varies an illumination intensity of the cold cathode tube using a burst modulation technique, and provides shutdown in the event of a ground fault.
Abstract:
An method of operating a neon stop lamp for a vehicle is described. By adjusting the lamp pressure, the then controlling the frequency and pulse width of the power, the lamp efficiency can be increased, while also shifting the chromaticity for the lamp to comply with automotive standards. The result is a small, efficient light source whose light may be reflected and focused, and whose color is correct for vehicle warning lights.
Abstract:
A planar fluorescent and electroluminescent lamp having two pairs of electrodes. Planar electrodes on an outer surface of the lamp create a plasma arc by capacitive coupling. The planar electrodes also cause embedded phosphor to emit light on the electroluminescent phenomena. In one embodiment, a second chamber is on top of the first chamber and light passes from a primary chamber through the second chamber, and is emitted by the lamp.
Abstract:
Electrodes 11 and 12 in a cold-cathode discharge lamp have a row of holes 13 arranged side-by-side along their length. The holes are formed by laser machining and extend at an angle of between about 25.degree. and 35.degree. to the normal, the holes in the two electrodes being oppositely inclined.
Abstract:
This invention provides for a light emitting device which comprises an envelope of electrically insulative material which defines within its boundaries an ionization chamber. A noble gas is disposed within the chamber and two spaced electrodes are located on the light emitting device such that the electrodes are in electrical communication with the interior of the chamber. At least one conductive member is disposed on the device and arranged to define a tortuous path between the two electrodes but without providing a direct electrical connection between the two electrodes. When a high frequency alternating voltage is applied to the electrodes the electrical interaction between the electrodes and the conductive member causes an ionization path between the electrodes to substantially follow the tortuous path.
Abstract:
A fluorescent low pressure discharge lamp is provided with a sintered electrode consisting of about 50% to 90% by weight of W and the remainder BaO or a mixture of BaO, CaO and SrO and an oxide of Y, Zr, Hf or an oxide of the rare earths.
Abstract:
The disclosure includes a glow-discharge lamp including: an elongate casing transparent to illuminating radiation and containing a plasma gas; a device for applying an electric field for maintaining a plasma in the so-called positive column region of the casing, the device including two electrodes forming an anode and a cathode located in the casing at each end thereof; and a radio-frequency or microwave cathode plasma source arranged in the casing in relation to the cathode-forming electrode, such as to generate a high-frequency discharge located on the surface of the electrode in order to generate the plasma. The disclosure also includes a lighting method of such a glow-discharge lamp.
Abstract:
An electrode for a discharge lamp is provided with a mayenite compound in at least a part of the electrode that emits secondary electrons, and a surface of a surface layer of the mayenite compound is plasma treated.