04484179 is referenced by 212 patents and cites 12 patents.

A touch sensitive device is arranged with substantially parallel surfaces which are at least partially transparent to light. A flexible membrane is supported above the top surface of the screen and when the overlay is flexed into contact with the screen, light which had passed through the screen, is trapped between the screen surfaces by total internal reflection. The edges of the screen are fitted with light detectors for gathering the trapped light. Using this arrangement positional determination of one or more screen touches is possible.

Title
Touch position sensitive surface
Application Number
140715
Publication Number
4484179
Application Date
December 23, 1981
Publication Date
November 20, 1984
Inventor
Leonard R Kasday
Plainsboro
NJ, US
Agent
David H Tannenbaum
Assignee
AT&T Bell Laboratories
NJ, US
IPC
G08C 9/00
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