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. 10, 1995
Filed:
Nov. 19, 1993
Shuuichi Ichinose, Nagano, JP;
Tadayuki Inaoka, Nagano, JP;
Seiko Epson Corporation, Tokyo, JP;
Futaba Corporation, Chiba, JP;
Abstract
A lighting device emits light by releasing electrons to an anode from a Joule-heated cathode and causes the electrons to collide against a phosphor on the anode side. A method of driving the lighting device repeats, at a predetermined lighting cycle, a heating period (t.sub.h) in which the cathode is heated by conduction, a lighting period (t.sub.on) in which the cathode is caused only to release electrons without conduction so that light is emitted, and a dummy period (t.sub.d) in which no conduction or emission of light occurs at the cathode. To variably adjust the lighting period (t.sub.on), adjustments are absorbed by the dummy period (td) to maintain the heating period (t.sub.h) constant at all times. With respect to the timing control of each period, the lighting period (t.sub.on) is controlled at a timing independent of the heating period (t.sub.h), whereas the heating period (t.sub.h) is controlled at a timing dependent on the lighting period (t.sub.on). This is preferred to facilitate the timing control of the lighting period (t.sub.on).