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. 14, 1998
Filed:
Sep. 04, 1996
Takao Takehara, Shizuoka, JP;
Shingo Okada, Saijou, JP;
Minebea Co., Ltd., Kitasaku, JP;
Abstract
This invention solves various problems of an inverter device caused by a winding transformer by using a piezoelectric transformer, and also provides a drive device for a cold cathode tube using a piezoelectric transformer so as to enable lighting and light control of the cold cathode tube. In a cold cathode tube lighting device having a cold cathode tube and piezoelectric circuit to light the cold cathode tube, a series resonance circuit is formed at primary side of the piezoelectric transformer. An operation control device is installed for ON-OFF control of the series resonance circuit, by a switching element, at timing with the phase advanced from the resonance frequency of the resonance circuit, and a chopper circuit for stepping-up the input voltage and supplying a power source to the resonance circuit is installed, and ON-OFF control of the power switching element of the chopper circuit is performed by the operation control device. That is, the power switch of the step-up chopper circuit is driven at the ON-time larger than that of the power switch of the inverter, and the cold cathode tube is connected to the secondary side of the step-up transformer.