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:
Apr. 27, 2021
Filed:
Nov. 19, 2018
Applicant:
Rohm Co., Ltd., Kyoto, JP;
Inventor:
Masatoshi Watanabe, Kyoto, JP;
Assignee:
ROHM CO., LTD., Kyoto, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02J 50/60 (2016.01); H02J 7/02 (2016.01); H01F 38/14 (2006.01); H02J 50/12 (2016.01);
U.S. Cl.
CPC ...
H02J 50/60 (2016.02); H01F 38/14 (2013.01); H02J 7/025 (2013.01); H02J 50/12 (2016.02);
Abstract
A transmission antenna includes a resonant capacitor and a transmitter coil coupled in series. The driver includes a bridge circuit structured to apply a driving voltage to the transmission antenna. A current sensor detects current Iflowing through the bridge circuit. A foreign object detector detects the current Iflowing through the bridge circuit while changing switching frequency of the bridge circuit and determines whether a foreign matter is present or absent based on a difference between two frequencies fand fgiving current lower than a peak by a predetermined ratio.