04198623 is referenced by 59 patents and cites 7 patents.

A display employing a horizontal and vertical grid of parallel infrared light beams in front of a cathode ray tube (CRT) face wherein a finger or other object may be placed against the face of the CRT to mark a spot thereon and the spot so marked will be detected by the interrupted beams. Infrared sources and detectors are located around the periphery of the CRT face and operate in different planes to more closely follow the curvature of the CRT face and thereby minimize parallax errors.

Title
Touch entry interactive cathode ray tube arrangement
Application Number
5/960142
Publication Number
4198623
Application Date
November 13, 1978
Publication Date
April 15, 1980
Inventor
Alphonse J Trasatti
Amherst
NH, US
Robert J Beairsto
Pembroke
NH, US
Albin A Hastbacka
Chelmsford
MA, US
Victor A Misek
Hudson
NH, US
Agent
Joseph E Funk
Louis Etlinger
Assignee
Sanders Associates
NH, US
IPC
G08C 21/00
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