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.

Date of Patent:
Dec. 04, 2012

Filed:

Mar. 27, 2009
Applicants:

Masahiro Yamamoto, Osaka, JP;

Syunsuke Ono, Osaka, JP;

Minoru Ozasa, Kyoto, JP;

Hiroji Morimoto, Nara, JP;

Inventors:

Masahiro Yamamoto, Osaka, JP;

Syunsuke Ono, Osaka, JP;

Minoru Ozasa, Kyoto, JP;

Hiroji Morimoto, Nara, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F 1/00 (2006.01); H05B 37/02 (2006.01); H05B 39/04 (2006.01); H05B 41/36 (2006.01); H05B 39/02 (2006.01); H05B 41/16 (2006.01); H05B 41/24 (2006.01); H05B 37/00 (2006.01); H05B 39/00 (2006.01); H05B 41/00 (2006.01); H01J 11/04 (2011.01); H01J 13/48 (2006.01); H01J 15/04 (2006.01); H01J 17/36 (2006.01);
U.S. Cl.
CPC ...
Abstract

The frequency of the alternating current to be supplied to the high-pressure discharge lamp is switched among a first frequency, a second frequency greater than the first frequency, and a third frequency smaller than or equal to the first frequency. In the switching, a period A, in which the alternating current of the third frequency is supplied, occurs at the beginning of each of the predetermined time intervals. A remainder of each of the predetermined time intervals includes a period B, in which the alternating current of the first frequency is supplied, and a period C, in which the alternating current of the second frequency is supplied, the periods B and C being alternately repeated, so as to control the period A to be longer than the period B and to have a length corresponding to a predetermined number of cycles, ranging from 5.5 to 50 cycles inclusive.


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