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:
Oct. 16, 2007
Filed:
Aug. 12, 2004
Applicants:
Shinji Ohta, Shizuoka, JP;
Masayasu Ito, Shizuoka, JP;
Inventors:
Shinji Ohta, Shizuoka, JP;
Masayasu Ito, Shizuoka, JP;
Assignee:
Koito Manufacturing Co., Ltd., Minato-ku, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B 37/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a discharge lamp lighting circuit, circuits, which respectively detect a voltage applied to a discharge lampand a current flowing through the discharge lamp are provided. Light on/off state, furthermore, light on/off state detecting meansis provided, which detects light on state or light off state of the discharge lamp, in that the absolute value of the difference between voltage and current detection values of the discharge lamp in light off state is larger than that in light on state.