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:
Mar. 28, 1989
Filed:
Nov. 30, 1987
Ikuya Nomoto, Akigawa, JP;
Kenji Kawabata, Ome, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A discharge lamp operating circuit includes at least a discharge lamp, a condenser and four switches. The condenser is charged and discharged through the discharge lamp by the turn-on and turn-off of the switches so that an AC current is caused to flow through the discharge lamp to operate the discharge lamp. A time required for the complete charging and discharging of the condenser is selected to be longer than a time scheduled for the charging and discharging of the condenser in one period. A switching frequency f.sub.0 at the time of heating of the discharge lamp and a switching frequency f at the time of operating of the discharge lamp has a relation of 2.ltoreq.f/f.sub.0 .ltoreq.10.