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:
Jun. 30, 1998
Filed:
Nov. 20, 1995
Koji Miyazaki, Yawata, JP;
Makoto Horiuchi, Nara, JP;
Shigeru Horii, Takatsuki, JP;
Satoshi Kominami, Osaka, JP;
Tatsushi Higuchi, Nishinomiya, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An apparatus that obtains a straight discharge arc during the whole lighting period, as well as provides a discharge lamp-lighting apparatus which can form a plurality of luminous intensity distribution patterns by changing the shape of the discharge arc. By supplying a lighting waveform equal to an acoustic resonance frequency which lighting waveform excites the mode to make the discharge arc straight. The acoustic resonance frequency is determined by the sound velocity in the discharge space medium and the height of a section orthogonal area to the electrode axis to the discharge lamp. The shape of the discharge arc at the time of rated lighting can be made substantially straight. By supplying the lighting waveform which amplifies the amplitude of the compressional wave emitted from the discharge arc during the period when the vapor pressure of the filler of the discharge lamp is low, the shape of the discharge arc can be made straight during the whole lighting period. By changing the ratio of the acoustic resonance frequency component, the shape of the discharge arc can be changed.