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:
Jun. 11, 2013
Filed:
Mar. 18, 2009
Tooru Nagase, Gyoda, JP;
Yoshiaki Komatsu, Gyoda, JP;
Shinichi Suzuki, Gyoda, JP;
Makoto Ohkahara, Gyoda, JP;
Hirokazu Harasawa, Gyoda, JP;
Yoshiaki Kuroda, Gyoda, JP;
Tooru Nagase, Gyoda, JP;
Yoshiaki Komatsu, Gyoda, JP;
Shinichi Suzuki, Gyoda, JP;
Makoto Ohkahara, Gyoda, JP;
Hirokazu Harasawa, Gyoda, JP;
Yoshiaki Kuroda, Gyoda, JP;
Iwasaki Electric Co., Ltd, Chuo-ku, Tokyo, JP;
Abstract
A high pressure discharge lamp ballast performs driving with a synthesized current waveform comprising a combination of first and second sets of current waveforms. The ballast controls content rates of each of the sets per unit time; detects a rotation synchronization signal for a color wheel; applies a synthesized current waveform in accordance with the synchronization signal and the content rates to a high pressure discharge lamp; and detects a lamp voltage. A period of each of the first and second sets equals to one rotation of the color wheel. The number of inversions of the second set is larger than that of the first set. The content rate of the second set is set to R% when the lamp voltage exceeds a value V, and the content rate of the second set is set to R% when lamp voltage falls below a value V'.