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US 4,727,294 AGranted
Electrodeless low-pressure discharge lamp
AssigneeU.S. Philips Corporation
InventorsHenk Houkes, Pieter Postma, Andreas G. Van Veghel
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AssigneeU.S. Philips Corporation
InventorsHenk Houkes, Pieter Postma, Andreas G. Van Veghel
Estimating the term…
An electrodeless low-pressure discharge lamp comprising a lamp vessel (1) which is sealed in a vacuum-tight manner and is filled with a metal vapor (for example mercury) and a rare gas, this lamp being provided with a core (4) of magnetic material (for example ferrite), while during operation of the lamp, and electric field is produced in the lamp vessel by means of a winding arranged to surround this core and a high-frequency supply unit connected thereto, the lamp vessel further being provided with an internal transparent conductive layer (11) and an external conductive layer (12), which during operation of the lamp is connected to one of the mains conductors and which together with the internal conductive layer (11) forms a capacitor.
A electrodeless low-pressure discharge lamp comprising a lamp vessel which is sealed in a vacuum-tight manner and is filled with a metal vapor and with rare gas, and a core of magnetic material surrounded by a winding connected to a high-frequency supply unit which, during operation of the lamp, produce an electric field in the lamp vessel, the inner side of the lamp vessel being provided with a transparent conductive layer, characterized in that an external conductive layer is disposed on a portion of the outer surface of the lamp vessel, said external conductive layer forming with the internal conductive layer a capacitor, and means for connecting said external conductive layer during operation of the lamp to the supply mains.
In an electrodeless fluorescent lamp having a lamp envelope, a discharge sustaining filling within said lamp envelope, a transparent conductive layer disposed on the inner surface of said lamp envelope, and a coil energizable by a high frequency signal for generating fields to sustain a discharge within the fill material, the improvement comprising:
Dependencies are inferred from the claim text.