Browse Prior Art Database

Light Encoder

IP.com Disclosure Number: IPCOM000095376D
Original Publication Date: 1965-Dec-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Drake, GV: AUTHOR

Abstract

This optical encoder is used in keyboard entry devices in which a unique binary coded signal is produced in response to the depression of each key. Optical encoder 1 includes a plurality of light-conducting plastic planes 21...27. Each plane has an opaque exterior surface.

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Light Encoder

This optical encoder is used in keyboard entry devices in which a unique binary coded signal is produced in response to the depression of each key. Optical encoder 1 includes a plurality of light-conducting plastic planes 21...27. Each plane has an opaque exterior surface.

Transparent code-defining openings 3 are arranged along three sides of each plane for receiving light from lamps 41...4-n. Transparent openings 51...57 are provided on one side of the encoder to permit light to escape from each plane. The light escaping from each plane is detected by photodetectors 61...67. Each lamp such as 41 is selectively energized by a circuit including contacts such as 71 of its respective key.

Light from the lamp 41 is received by the planes 24, 25 and 26 in accordance with the arrangement of openings 3 adjacent the lamp. A part of the light received in planes 24, 25 and 26 is emitted through openings 54 55 and 56 and sensed by detectors 64 65 and 66. Thus, the binary coded signal 00011 10 is produced at the outputs of the detectors when key contacts 71 are closed.

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