Patent · US Expired

Radio-wave transmission system of keyless entry system for automotive vehicle devices

US4897644A · kind A · utility

82Cited by
12References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 3, 1987
Grant dateJan 30, 1990
Priority date
Expiry dateSep 3, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T70/5978
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A keyless entry system allows operation of door locks, a trunk lid lock, a glove box lid lock, a steering lock device or so forth without mechanical keys. The keyless entry system includes electrically disconnected transmitter and a controller. The controller is connected to operate the devices. The transmitter is adapted to send a present code-indicative radio signal to the controller, which then compares the code contained in the radio signal from the transmitter with a preset code. The controller is provided with a dual-antenna system which ensures clear data transmission between the transmitter and the controller. The dual-antenna system includes at least a pair of antennas oriented essentially perpendicular to each other.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.