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. 24, 2016
Filed:
Mar. 15, 2013
Aisin Aw Co., Ltd., Anjo-shi, Aichi-ken, JP;
AISIN AW CO., LTD., Aichi-ken, JP;
Abstract
A navigation device includes a GPS receiver, map data including tunnel data and periodically acquires a vehicle's speed to provide guidance on the current position N acquired at the GPS receiver, and when GPS radio waves become unreceivable after the vehicle passes a tunnel entrance, calculates a travel distance according to a vehicle speed and a time T up to a branch, and continues providing guidance on the current position up to the branch. After passing the branch, the navigation device suspends guidance, calculates a distance La between the branch and a tunnel exit, which is shorter, and when GPS radio waves are not received even after a movement distance from the branch exceeds distance La, after passing the branch, determines a road whose distance is longer as the road being traveled, and provides guidance on the current position.