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:
May. 23, 2006
Filed:
Jan. 21, 2004
Shinji Tani, Nishio, JP;
Yoshichika Abe, Anjo, JP;
Shinji Tani, Nishio, JP;
Yoshichika Abe, Anjo, JP;
Anden Co., Ltd., Anjo, JP;
Denso Corporation, Kariya, JP;
Abstract
A control device of LEDs includes a lighting-up circuit and a lighting-out circuit, both of which generate pulse signals being pulse-width modulated by varying cycles and corresponding duty ratios based on an input signal during a start-up period and a falling period, respectively. The control device then provides LEDs with the electric current relative to the pulse signals. Both of the lighting-up circuit and lighting-out circuit vary the cycles and corresponding duty ratios of the pulse signals, so that a luminance variation characteristic of the LEDs becomes nonlinear, leading to being approximated to a luminance variation characteristic of an electric bulb.