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. 21, 1995
Filed:
Oct. 06, 1994
Matsushita Electric Works, Ltd., Kadoma, JP;
Abstract
A device for operating a high pressure gas discharge lamp with an electronic ballast having a lamp power factor of substantially 1.0. The device utilizes a lamp equi-luminescence performance curve X which is obtained for the lamp to give a lamp voltage and a lamp wattage that can vary along the curve X while keeping an arc luminescence of an arc developing between electrodes of the lamp at substantially constant level. The arc luminescence is defined as a maximum luminescence of the arc having varying luminescence along the length of the arc. The constant level determined to be the luminescence that the lamp gives at the rated lamp voltage. The curve X is analyzed to determine a specific lamp voltage Va at which curve X gives a maximum lamp wattage Wa. The lamp is operated in accordance with a first load characteristic for controlling to increase the lamp wattage substantially along the lamp performance curve X until the lamp voltage increases to the specific lamp voltage Va. After the lamp voltage increases beyond the specific lamp voltage Va, the lamp is operated in accordance with a second load characteristic for controlling to keep the lamp wattage above the lamp performance curve X but not exceeding the maximum lamp wattage Wa as well as to keep the arc luminescence below a predetermined limit level.