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:
Jan. 25, 2000
Filed:
Apr. 16, 1999
Hirokazu Ohtake, Kanagawa-ken, JP;
Toshiba Lighting & Technology Corporation, Tokyo, JP;
Abstract
The present invention provides an improved power factor and lower harmonic distortion in the power supply circuit of a high frequency discharge lamp. An 'extra' circuit path is provided so that the driving power to the lamp will 'see' a load that significantly reduces the harmonic distortion and tends to cause the power factor to approach '1'. In a preferred embodiment of the invention this is accomplished by providing a third capacitor with which the load circuit forms an in-series resonance circuit with the discharge lamp and its associated current-limiting inductance. The new circuit arrangement provides a high frequency current passage not provided in known lighting circuits of this type that raises the power factor and lowers harmonic distortion.