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. 05, 1982
Filed:
Nov. 28, 1980
Isao Kaneda, Otsu, JP;
New Nippon Electric Company, Ltd., Osaka, JP;
Abstract
A parallel circuit of a capacitor and a switching element is connected to a hot cathode discharge lamp lighting device using a high frequency and high voltage generating means for permitting the flow of current into the filaments of the hot cathode type discharge lamp only at the lamp starting time. The switching element of the parallel circuit is a current controlled resistance element, such as a switching semiconductor, having a break-over voltage V.sub.BO lower than the capacitor terminal voltage during the initial ignition period and higher than the capacitor terminal voltage during the reignition or operation period, whereby the filament current to the discharge lamp may be used for preheating of the filament in the initial ignition period. The filament current may be stopped or reduced by turning off of the switching element by raising the terminal voltage of the capacitor in the reignition period during normal operation. Thus, the lumen-per-watt efficacy of the lighting device is improved since the filament current is substantially eliminated during the lamp operation. After the initial ignition period it is preferred to use the capacitor of the parallel circuit as an intermittent commutation capacitor in the high frequency and high voltage generating oscillation circuit having an oscillation capacitor, a nonlinear inductor and a thyristor.