High efficiency lamp

Abstract

A high efficiency lamp is shown which includes an evacuated envelope, at least a portion of which is light-transmitting. A phosphor layer and anode electrode in engagement therewith is provided at the light-transmitting portion of the envelope. A field emission structure is located inside the envelope, which structure includes spaced plate-like cathode and accelerator electrodes and an insulator separating and insulating the cathode and accelerator electrodes. The accelerator electrode is formed with an array of apertures therethrough, and the cathode electrode is formed with an array of needle-like members projecting from one surface thereof and into the apertures in the accelerator electrode. Electrons are drawn from the tips of the needle-like members by application of a first voltage between the cathode and accelerator electrodes, and emerge from the tips over relatively wide solid overlapping beam angles. The overlapping electron beams are attracted to the anode electrode and impinge upon the phosphor layer for production of light emission from the phosphor. A high dc voltage power supply may be located inside the base of the lamp for energization of the lamp. Alternatively, ac voltages may be supplied to the lamp electrodes for energization thereof. A second accelerator electrode in the form of a ring may be provided adjacent the field emission structure through which electrons pass in travelling from the field emission structure to the anode.

Dependencies are inferred from the claim text.