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. 12, 1998
Filed:
Nov. 26, 1996
Koichi Toyama, Kariya, JP;
Noboru Yamamoto, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
In a discharge bulb control, a time constant circuit comprised of a capacitor and a resistor is used to determine an electric power to be supplied to a discharge bulb. During a warm-up period of the discharge bulb, the capacitor is charged to produce a voltage which varies, toward a predetermined voltage, with an electric current flowing thereto so that the electric power is increased gradually. After the warm-up control, the time constant for charging the capacitor is reduced to maintain the capacitor voltage at the predetermined voltage. Even with the current leakage occurring in the capacitor after the warm-up control, the electric power is controlled by the predetermined voltage which is not influenced by the current leakage. Thus, the electric power applied to the discharge bulb after the warm-up control can advantageously be maintained at the required level.