Abstract:
An electrodeless low pressure discharge lamp comprises an envelope made from a straight tube and a reentry cavity sealed to one of tube's ends. The cavity has several hollow ferrite cores separated from each other with a few mm distance. Each ferrite core has an induction coil of few turns wound around the core. Each cavity has a cooling copper tube or rod located inside the ferrite core that removes heat from the cores and dumps the heat into a heat sink welded to the cooling tube/rod thereby keep the temperature of the ferrite cores below their Curie point. Each induction coil is electrically connected to the matching network while all matching networks are connected in parallel to the high frequency power source (driver). Inductively coupled plasmas generated in the envelope by several core/coil assemblies produce axially uniform UV and visible radiation.
Abstract:
In a microwave-excited discharge lamp of the present invention, a rare gas 2, a mercury halide 3 as a buffer material, and a metal halide 4 as a luminous material are sealed within an discharge tube 1. This achieves a microwave-excited discharge lamp having excellent stability and a variety of light colors.
Abstract:
A mercury-free metal halide lamp includes an arc tube including a pair of electrodes inside the tube. In the arc tube, a rare gas and a metal halide are contained, and no mercury is contained. The mercury-free metal halide lamp is horizontally operated such that the pair of electrodes is substantially horizontal. The mercury-free metal halide lamp further includes magnetic field applying means for applying a magnetic field including a component substantially perpendicular to a straight line connecting heads of the pair of electrodes in a substantially vertical direction. The density of halogen atoms evaporated during steady-state operation with respect to unit inner volume of the arc tube is 20 &mgr;mol/cc or more.
Abstract:
A flat panel display device comprises a cathode on a first substrate for emitting electrons, a magnetic plate including first region focusing electrons emitted from the cathode to display an image and second region for applying the uniform magnetic field into the holes in the first region, and a fluorescent layer on the second substrate, on which the electrons outputted from the holes are impacted. In the second region, there are holes having the same shape and pitch as the first region.
Abstract:
A plasma processing system includes a processing vessel for housing therein an object to be processed. In the upper portion of the processing vessel, a substantially disk-shaped electrode plate having a facing surface facing the object is provided. A radio-frequency wave supply unit supplies radio-frequency waves having a flattened waveform which forms substantially a sinusoidal wave whose crest and trough portions are substantially horizontally flattened. The radio-frequency waves supplied from the supply unit are propagated in diametrically opposite directions on the facing surface of the electrode to form standing waves. Similar to the supplied radio-frequency waves, the standing waves also have a waveform which forms substantially a sinusoidal wave whose crest and trough portions are substantially horizontally flattened.
Abstract:
In accordance with one specific embodiment of the present invention, the closed drift hollow cathode comprises an axisymmetric discharge region into which an ionizable gas is introduced, an annular electron emitting cathode insert disposed laterally about that discharge region, a surrounding enclosure, an aperture in that enclosure disposed near the axis of symmetry and at one end of that region, and a magnetic field within that region which is both axisymmetric and generally disposed transverse to a path from the cathode insert to the aperture. An electrical discharge is established between the cathode insert and the enclosure. The electrons emitted from the cathode insert drift in closed paths around the axis, collide with molecules of ionizable gas, and sustain the discharge plasma by generating additional electron-ion pairs. Ions from the plasma bombard the cathode insert, thereby maintaining an emissive temperature. Electrons from the plasma diffuse to and escape through the aperture to provide the electron emission. The closed drift nature of the discharge circumferentially distributes the heating of the cathode insert and the utilization of the electron emitting capabilities thereof. The discharge current controls the maximum value of the electron emission.
Abstract:
An inductively driven gas discharge lamp assembly (40) includes an electrodeless lamp (42), an inductive drive coil (44) disposed about the lamp, and a shield (10) disposed over an end portion (50) of the lamp. The shield (10) has a number of turns (12) of electrically conductive material, such as wire, with each of the turns being disposed generally coaxially about the central, longitudinal axis (20) of the drive coil (44). The turns (12) together form a continuous spiral helix and are shorted together via a number of electrical conductors (14) that are angularly disposed about the axis (20). These electrical conductors (14) extend generally perpendicularly to the turns (12) and are connected to the ground node (26) of a d.c. to a.c. inverter circuit 46 that is used to drive coil 44. This arrangement provides good r.f. electric field and magnetic field shielding and permits the use of relatively few turns (12) at a relatively large spacing of the turns so as to minimize the interference of the shield (10) on the amount of light emitted from the lamp (42). Also disclosed is another embodiment (30) in which the turns (32) each comprise a single loop rather than a continuous spiral helix.