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:
Feb. 12, 2008
Filed:
Nov. 30, 2004
Masahiro Umewaka, Gunma-ken, JP;
Hiroya Yamamoto, Gunma-ken, JP;
Keitarou Sekine, Tokyo, JP;
Akira Hyougo, Chiba, JP;
Keiji Morijiri, Gunma-ken, JP;
Masahiro Umewaka, Gunma-ken, JP;
Hiroya Yamamoto, Gunma-ken, JP;
Keitarou Sekine, Tokyo, JP;
Akira Hyougo, Chiba, JP;
Keiji Morijiri, Gunma-ken, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Tokyo University of Science, Tokyo, JP;
Abstract
There is disclosed a tuning circuit having a coil and a capacitor comprises a resistance-adjustment circuit connected in parallel with the coil and the capacitor. The resistance-adjustment circuit changes a resistance of the tuning circuit when resonant. The resistance-adjustment circuit comprises a series circuit of a resistor and a switching element having an ON-resistance smaller than the resistance of the resistor, and turning on/off the switching element causes the resistance of the tuning circuit when resonant to change.