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:
Dec. 24, 2002
Filed:
Aug. 30, 2001
Denso Corporation, Kariya, JP;
Abstract
In a control apparatus for a self-heating type cold-cathode discharge tube, a microcomputer determines boosting time based on a detected surrounding temperature of the cold-cathode discharge tube. The boosting time is increases as the detected temperature decreases. A switching circuit, powered from a direct current power supply, performs a switching operation based on a determination output from the microcomputer. An inverter circuit actuates the cold-cathode discharge tube based on the switching operation which is duty-controlled. The duty ratio is determined to be higher when the detected surrounding temperature is within a predetermined low temperature range than outside the predetermined low temperature range.