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. 17, 2003
Filed:
Aug. 29, 2001
Tatsuya Wakamatsu Nagoya, Nukata-gun, JP;
Toshihiro Wakamatsu, Nagoya, JP;
Denso Corporation, Kariya, JP;
Abstract
An in-vehicle key check system has a security ECU, a transmitter and a receiver for communication with a portable electronic key. The ECU communicates with the electronic key each time a key check condition is satisfied, and checks whether the electronic key is an authorized one based on response signals from the electronic key. The check result indicating that the electronic key is the authorized one is stored in a memory. This check result is erased when a predetermined time elapses or when the electronic key is likely to be taken out from the vehicle. When another check condition is satisfied, the ECU refers to the memory and skips the key check operation if the previous check result is stored in the memory.