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:
Nov. 08, 2005
Filed:
Dec. 20, 2002
Naoki Onishi, Hirakata, JP;
Shigeru Ido, Shijonawate, JP;
Yoshinobu Murakami, Hirakata, JP;
Minoru Yamamoto, Hirakata, JP;
Naoki Onishi, Hirakata, JP;
Shigeru Ido, Shijonawate, JP;
Yoshinobu Murakami, Hirakata, JP;
Minoru Yamamoto, Hirakata, JP;
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
A discharge lamp operation apparatus includes an AC power supply (), a voltage converting circuit (), an inverter circuit (), a load circuit (), a controller (), and a pulse voltage superimposing section (). The pulse voltage superimposing section () controls the switching elements (Q, Q) of the inverter circuit () to superimpose a pulse voltage to the voltage applied across the discharge lamp (LA). The period until the discharge lamp (LA) is lighted is divided into a preheating period to preheat the discharge lamp and a startup period to start the discharge lamp. During the startup period, the controller () raises gradually the output voltage (Vdc) of the voltage converting circuit (), and the voltage superimposing section () superimposes the pulse voltage on the voltage applied across the discharge lamp (LA).