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:
May. 10, 2005
Filed:
Sep. 24, 2003
Kazutoshi Mita, Kanagawa-ken, JP;
Kazutoshi Mita, Kanagawa-ken, JP;
Toshiba Lighting & Technology Corporation, Tokyo, JP;
Abstract
A high-pressure discharge lamp lighting apparatus including a DC power source, an inverter, and a resonator is presented. The apparatus also includes an inverter controller for controlling the inverter according to its variable frequency oscillation function by selectively impressing a first frequency in a stable operation window free from causing acoustic resonance in the high-pressure discharge lamp, and a second frequency higher than the first frequency to the inverter, a lamp wattage detector, and a time ratio controller for controlling a time ratio of an operation time at the first frequency and an operation time at the second frequency so that the inverter outputs are alternately impressed to the high-pressure discharge lamp at an adequate time at the first frequency and the second frequency. The time ratio is based on a lamp voltage of the discharge lamp detected in the steady lighting state using the lamp wattage detector.