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. 22, 2010
Filed:
Aug. 29, 2007
Hidekazu Maezawa, Nagano, JP;
Koichiro Yano, Nagano, JP;
Hidekazu Maezawa, Nagano, JP;
Koichiro Yano, Nagano, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
A terminal device receives satellite signals from a plurality of satellite positioning system (SPS) satellites and locates a position. The terminal device periodically calculates a first drift dfof a local oscillator using a reference frequency Hr, calculates a search range of the satellite signal using the first drift df, calculates a second drift dfof the local oscillator using a reception frequency of the satellite signal, calculates a reference frequency error β which is an error of the reference frequency by calculating a difference between the first drift dfand the second drift df, and calculates an error correction value βav of the reference frequency by subjecting a plurality of the reference frequency errors β to a statistical process.