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:
Aug. 30, 2011
Filed:
Sep. 26, 2008
Yoshinori Watanabe, Chita-gun, JP;
Tomoya Imagawa, Anjo, JP;
Yuki Nakai, Nagoya, JP;
Makoto Ono, Kariya, JP;
Takemi Ueno, Okazaki, JP;
Hiroki Tanaka, Takahama, JP;
Yoshinori Watanabe, Chita-gun, JP;
Tomoya Imagawa, Anjo, JP;
Yuki Nakai, Nagoya, JP;
Makoto Ono, Kariya, JP;
Takemi Ueno, Okazaki, JP;
Hiroki Tanaka, Takahama, JP;
DENSO CORPORATION, Kariya, JP;
Abstract
A navigation device realizes such processing as map display and route guidance based on map data stored in a memory card. The data in the memory card tends to be volatilized with an increase in the frequency of reading of data. Therefore, the data that are highly frequently read out are held in a RAM so as to be read from the memory card at a decreased frequency. Further, the passage of time is calculated from the date and hour the data are recorded in the memory card, and the whole data in the memory card are refreshed every time when the passage of time exceeds a threshold value T