04398172 is referenced by 101 patents and cites 9 patents.

A vehicle monitor (10) apparatus for monitoring vehicles (14) in a monitoring location (17). A vehicle unit (12) mountable in a vehicle includes circuitry (21) for transmitting, on a continuous repetitive basis, information characterizing the vehicle and unique thereto. In addition, a monitoring unit (16) mountable at the monitoring location includes circuitry (33) for receiving information transmitted by the vehicle unit. Such monitoring circuitry includes an infrared light receiver (29) and a preamplifier with ambient light compensation circuitry (100) connected thereacross.

Title
Vehicle monitor apparatus
Application Number
6/271476
Publication Number
4398172
Application Date
June 8, 1981
Publication Date
August 9, 1983
Inventor
Freddie G Williams
Huntington Beach
CA, US
E James Lane
Highland
MI, US
Roger A Keller
Livonia
MI, US
Robert J Carroll
Plano
TX, US
Agent
R A Johnston
J G Lewis
C H Grace
Assignee
Eaton Corporation
OH, US
IPC
H04B 9/00
G08C 17/00
G08G 1/04
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