Passive fiber optic keyboard
US4442425A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 13, 1981 |
| Grant date | Apr 10, 1984 |
| Priority date | — |
| Expiry date | Nov 13, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S200/47
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electrically passive keyboard is provided with an array of keys. Each key is provided with an actuating bar which when depressed cooperates with a plurality of coded shutters. Each shutter is arranged to intercept a beam of light passing from light projecting elements to light collecting elements. Light pulses generated at a light source are coupled to the projecting elements with fiber optic cables. Decoding logic is coupled to the light collectors with fiber optic cables. Delay elements are provided in series in the fiber optic cables so that the decoding elements receives a plurality of binary coded light signals in a predetermined timed sequence which are converted into binary coded electrical signals at a point remote from the electrically passive keyboard.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.