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:
Feb. 28, 1989
Filed:
Mar. 22, 1988
TDK Corporation, Tokyo, JP;
Abstract
A discharge lamp device includes a tube, and a cathode disposed in said tube and made of a valence-compensated semiconductor ceramic material, or a forcibly reduced semiconductor ceramic material, or a valence-compensated and forcibly reduced semiconductor ceramic material. Since the cathode does not include an electron-emitting material, but uses a semiconductor ceramic material, no vapor is produced by the cathode and also the cathode does not react with mercury vapor filled in the tube. Therefore, the discharge lamp device has improved characteristics such as greater heat resistance, better chemical resistance, and improved discharge characteristics. The discharge lamp device is less costly because the semiconductor ceramic material used as the cathode is inexpensive.