05027314 is referenced by 106 patents and cites 11 patents.

A system and method for tracking a number of subjects in a plurality of areas is shown to include a plurality of transmitters, wherein at least one transmitter is associated with each subject, each transmitter transmits a light based signal representative of an identifying code unique to that transmitter, a plurality of receivers, wherein at least one receiver is associated with each area, each receiver converts transmitted light based signals to electrical signals and validates the electrical signal to determine whether such electrical signals are representative of the unique identifying codes associated with the transmitters, and a central processing member, connected to each of the receivers, for recording those electrical signals which are representative of the unique identifying codes for recording the receiver which determined that such electrical signals are representative of the unique identifying codes associated with the transmitters and for determining in which area the transmitter is actually located.

Title
Apparatus and method for position reporting
Application Number
169285
Publication Number
5027314
Application Date
March 7, 1990
Publication Date
June 25, 1991
Inventor
Wayne Duncan
Newark
DE, US
Gary Linwood
Newark
DE, US
Agent
Woodcock Washburn Kurtz Mackiewicz & Norris
Assignee
United Manufacturing Co
DE, US
IPC
G08B 5/22
G08B 23/00
G06F 1/00
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