WO/2008/005725 is referenced by 2 patents.

A system, comprising: an electro optical identification tag comprising a retroref lective layer, a light modulator positioned over the retroref lective layer, and a control unit capable of modulating the light modulator according to a communication code; and an electro-optical transceiver comprising a light source capable of illuminating the optical identification tag and further comprising an optical sensor capable of receiving a signal reflected from the optical identification tag.

Title
Active electro-optical identification
Application Number
PCT/US2007/071957
Publication Number
2008/005725
Application Date
June 23, 2007
Publication Date
January 10, 2008
Inventor
Thomas Fred Charles Iii
Agent
ALTMAN Daniel E
Assignee
Thomas Fred Charles Iii
Britta Technologies
IPC
G06K 19/073
G06K 19/07
G01S 07/481
G01S 17/74
G06K 07/10
View Original Source