The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 04, 1989
Filed:
Jul. 17, 1987
Ivor Brodie, Palo Alto, CA (US);
SRI International, Menlo Park, CA (US);
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.