Fluorescent lamp with integral conductive traces for extending low-end luminance and heating the lamp tube

Abstract

A fluorescent lamp (10) includes a tube (12) and a fluorescent gas mixture sealed in the tube. A phosphor layer (20) is deposited on the interior surface of the tube. A pair of internal electrodes (14), connected by a first circuit (16) to a first power supply (18), are located in the tube at opposite ends thereof. The first power supply (18) causes a high-intensity arc discharge between the pair of internal electrodes (14) and, in turn, produces fluorescent light. An opposing pair of conductive traces (22, 24) connected by a second circuit (26) to a second power supply (28), are silk-screened onto the exterior surface of the lamp tube (12) along the length thereof. The second power supply (28) causes the opposing pair of conductive traces (22, 24) to produce a transverse electric field that creates a low-intensity transverse discharge. The low-intensity transverse discharge is used to lower the luminance range of the fluorescent lamp. The conductive traces are formed of a conductive frit, such as a silver ceramic frit. After silk-screening, the lamp tube (12) is fired to melt the frit onto the tube. At least one of the conductive traces (22, 24) is connected by a third circuit (30) to a third power supply (31). The resistivity of this conductive trace is such that the conductive trace functions as a heater when it receives power from the third power supply.

Dependencies are inferred from the claim text.