Abstract:
An electrodeless lamp includes a bulbous lamp envelope enclosing an inert gas and a vaporizable metal fill, the lamp envelope having a reentrant cavity and an envelope bottom, an electromagnetic coupler positioned within the reentrant cavity, and a thermal shield positioned in proximity to the envelope bottom and configured to increase the temperature of the envelope bottom. By increasing the temperature of the envelope bottom, a cold spot is prevented. As a result, light output at low temperatures is comparable to light output at room temperature.
Abstract:
A metal halide lamp having excess amount of red radiation, well beyond a tungsten halogen lamp of the same color temperature. The deep saturated red being accomplished with reasonable efficacy utilizing a mixture of sodium and rare earth halides, additional broadening of the Na “D” lines and filtering out the yellow radiation at about 590 nm. The red radiation is comparable to the commercially available white high pressure sodium lamp red radiation.
Abstract:
A method and system of modifying one feature of a high-pressure lamp without significantly affecting the other features, the features including the luminosity, the color rendering index, the color temperature, or the deviation from the black body locus (DUV). An arc discharge is initiated within the arc tube with a ballast imposing an alternating current waveform on the electrodes. In this way, the electrodes change from positive to negative in each cycle of operation. The waveform of each cycle is modified through the ballast to energize one electrode as positive or negative for a longer time than the other electrode, thereby altering the temperature distribution within the arc tube by changing the cold spot and hot spot temperatures in a lamp which has modifiable emission features.
Abstract:
An electrodeless inductively-coupled fluorescent lamp which operates at radio frequencies and contains an induction coil (1) which is inserted in a reentrant cavity (2) of the envelope (7) and is spread along the length of the reentrant cavity (2). The coil (1) is disposed within a cylinder (14) of thermally conductive metal. The use of the spread coil provides for reduction of starting and operation voltages of the lamp and results in lowering of the energy of ions bombarding the inner surface of the envelope (7) and the cavity (2) and therefore improves lamp maintenance and increases lamp life.
Abstract:
This invention relates to dimmable metal halide lamps using ceramic arc tubes for the application of energy saving, mood control, and constant light output over the life of the lamp. Under dimmed conditions, as low as 50% of rated wattage, the color temperature (CCT) can remain substantially the same and be perceived by the viewer as a constant color light source. Furthermore, the invention improves the color rendering index (CRI) and the efficacy of the lamp under dimmed operation. Such improvements are provided by placing a metal shield on an end of the arc tube, whereby the emissivity of the shield is lower than the emissivity of the ceramic in the arc tube, whereby cold spot temperature in the lamp is increased, even under dimmed conditions.
Abstract:
A substantially flat, gas filled, arc discharge fluorescent lamp having an internal path in which the arc travels, where the path is formed by vertical sections between a substantially flat top and bottom surface. The path length can be controlled along with the height of the lamp to provide a wide range of lumens per unit volume while improving lamp life at low cost. A reflective coating, formed adjacent to the phosphor coating within the path, directs light to where wanted, while obviating the need for a separate reflector in the lamp fixture. One application of the present inventive lamp is to replace incandescent lamps by virtue of being mechanically interchangeable by virtue of having the flexibility for accommodating a small ballast within the lamp assembly.
Abstract:
An electrodeless inductively-coupled fluorescent lamp which operates at ro frequency comprising a bulbous envelope (1) filled with rare gas and metal vapor. A reentrant cavity (4) and an induction coil (6) are disposed in the cavity (4). The inner walls of the envelope (1) and the cavity (4) have a protective coating (3) and a phosphor coating (2). A metal Faraday cylinder (12) welded to the lamp base (13) is disposed between the cavity (4) and the coil (6) to reduce capacitive RF voltage between the coil and the plasma to improve lamp maintenance and remove heat. A tubulation (16) is disposed on the lamp axis to evacuate the envelope (1). The proximal end of the tubulation (16) has an expansion (20) with the volume (23) where the initial capacitive discharge is ignited. The RF coil voltage needed for the ignition of the capacitive discharge in the expansion area (23) is substantially lower than that needed for the ignition of the capacitive discharge in the area (14) along the inner cavity walls (4) to decrease the lamp starting voltage. In one of the embodiments of the present invention the expansion is conically shaped and in another it is cylindrically shaped and is used to generate the inductive plasma to increase the light generation in the top part of the bulb (28) and improve light output through the bulb top surface (27).
Abstract:
A flat compact fluorescent lamp is disclosed. The lamp contains a fill of mercury and inert gas. The lamp includes a glass front panel (1) having an inner surface and a glass bottom panel (2) also having an inner surface. A convoluted glass partition (3) having an eccentric spiral shape and smooth bends is disposed between the inner surfaces of the front and bottom panels and with the bottom panel (2) defines a channel (4) in the lamp. The channel (4) has a fairly uniform width. A phosphor coating (6) of a predetermined density between about 3 and 5 mg./cm.sup.2 is disposed on the inner surface of the channel (4) and a phosphor coating (8) of a predetermined density of between about 0.5 and 1.5 mg./cm.sup.2 is disposed on the inner surface of the front panel (1). Two electrodes (14a & 14b) are disposed at opposite ends of the spiral in the lamp to form an arc which emits UV light to excite the phosphor (6 & 8) to emit light. Substantially all the light emerging from the phosphor 6 on the channel (4) passes through the thinner phosphor (8) coating on the front panel (1).
Abstract:
A fluorescent lamp (2) having at least two phosphor coatings (12) on the surface of the sealed lamp bulb, typically an inner surface. There is variable driving means which preferentially activates one phosphor and not the other phosphors, at one arrangement or setting or configuration of the driving means, while at another setting the driving means activates in addition a different or several different phosphors. Each phosphors may be a blend of phosphors and the phosphors and/or blends may be overcoated upon one another forming multiple layers or all mixed together and applied as a one layer coating on the lamp surface. The inventive lamp uses standard fabricating techniques and materials, but allows the user to change the color temperature of the lamp by controlling parameters of the electrical driving signal, that is the, spectrum and quantity of light emitted are changed in response to the changed driving signal such that the user can arrange the light output to be more or less blue or red or to balance the longer wavelengths perceived against the shorter wavelengths perceived.
Abstract:
Electrodeless, low pressure, fluorescent discharge lamp of high aspect ratio, with a substantially flat spiral rf coil adjacent a back face (and insulated therefrom), that emits light through a front surface or selected portions under control of internal reflective and phosphor coatings placement to afford minimum resonance trapping, high efficiency and uniform illumination of high specific intensity over a selected area of the front wall.