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. 25, 1999
Filed:
Feb. 10, 1997
Koito Manufacturing Co., Ltd., Tokyo, JP;
Abstract
A lighting circuit for a discharge lamp comprises abnormality detection means for detecting an input voltage and/or an input current to be input to a lighting circuit from a power supply and stopping power supply to a discharge lamp when detecting an abnormality in the value of the input voltage and/or the value of the input current. First and second reference values or reference ranges for comparison (the first reference value or reference range is smaller than the second reference value or reference range) are set for the input voltage and/or the input current. When the state where the value of the input voltage and/or the value of the input current is equal to or smaller than the first reference value or the first reference range continues for a predetermined time or longer, the abnormality detection means stops power supply to the discharge lamp. When the state where the value of the input voltage and/or the value of the input current is equal to or greater than the second reference value or the second reference range continues for a predetermined time or longer, the abnormality detection means permits power supply to the discharge lamp.