Vehicle key-verifying apparatus and method with decreased verification time period feature
US6549116B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1999 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Jul 1, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2009/00793
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A key-verifying apparatus for quickly determining whether a key is legitimate, even when a legitimate key is determined not to be legitimate in at least a first iteration of key-verifying processing due to a communication fault or the like. An immobilizer ECU sends query data to a key transponder, receives response data from the transponder, generates auto-response data from the query data and key-discriminating data, and repeats key-verifying processing through determination as to whether the key is a legitimate until the key is determined to be legitimate or until a predetermined number of iterations are completed. The immobilizer ECU, after receiving the response data from the transponder in the present key-verifying processing, immediately initiates sending of query data in the subsequent key-verifying processing, and so the cycle for determining whether a key is legitimate is shortened compared to the cycle of a verifying apparatus that initiates sending of subsequent query data after determining that a key is not legitimate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.