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Optical Keyboard

IP.com Disclosure Number: IPCOM000096317D
Original Publication Date: 1963-Mar-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Sharp, JJ: AUTHOR [+2]

Abstract

The keyboard consists of a mesh of light guides, one of which is shown in A. A collimating lens 1 collects light from lamp 2 and directs it through sections 3 of the guide to photosensitive cell 4. Each light guide has openings 5 at the intersections with other light guides. The openings form the keys of the keyboard and each has a sponge base 6.

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Optical Keyboard

The keyboard consists of a mesh of light guides, one of which is shown in A. A collimating lens 1 collects light from lamp 2 and directs it through sections 3 of the guide to photosensitive cell 4. Each light guide has openings 5 at the intersections with other light guides. The openings form the keys of the keyboard and each has a sponge base 6.

In use, the keyboard is operated by placing a finger on the sponge base in the appropriate key. This interrupts the light path in the two guides which intersect at that key. Thus, the photo-cells of the two guides are affected to set latch circuits which produce coded output. An audio signal can also be produced to indicate when a latch circuit has been set. The latch circuit is reset after a predetermined delay period.

Drawing B shows an alternative arrangement. A key 7, having a hollow cruciform internal structure, is located at each intersection of the light guides. The key is normally spring-biased into the position shown to allow free passage of light. It is manually depressed to interrupt the light in the intersecting light guides.

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