Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Electric Works Co Ltd
Original Assignee
Matsushita Electric Works Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Works LtdfiledCriticalMatsushita Electric Works Ltd
Priority to JP8114675ApriorityCriticalpatent/JPS524667A/en
Publication of JPS524667ApublicationCriticalpatent/JPS524667A/en
PURPOSE:To provide a device flowing appropriate pre-heating current through the filaments, and making the lamp capable of lighting even with one filament burnt out.