3621268 is referenced by 47 patents and cites 12 patents.

Contactless touch switch in which an electric pulse is produced by light impinging on a photosensitive cell due to reflection of a beam of light. According to the invention the touch switch is constructed in such a manner that the beam of light normally emerges through an aperture in the touch switch housing, which is closed on all sides, and that the photosensitive cell, which is protected by screening, can receive substantially only those rays which are produced by reflection of the beam of light at an object, preferably a finger covering said aperture.

Title
Reflection type contactless touch switch having housing with light entrance and exit apertures opposite and facing
Application Number
04/782,547
Publication Number
3621268
Application Date
December 10, 1968
Publication Date
November 16, 1971
Inventor
Georg Straimer
Kurt Friedrich
Agent
Charles L Johnson Jr
Isidore Togut
Philip M Bolton
Percy P Lantzy
Walter J Baum
C Cornell Remsen Jr
Assignee
International Standard Electric Corporation New York NY
IPC
G06m 07/00
G01j 03/50
G01j 03/34
H03K 17/96
H03K 17/94
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