Optical keyboard with common light transmission members
US4417824A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1982 |
| Grant date | Nov 29, 1983 |
| Priority date | — |
| Expiry date | Mar 29, 2002 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J5/08
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A keyboard assembly (FIG. 1, 11) is constructed of first light transmission members (13) second light transmission members (15), a key actuation assembly (17) having a matrix of keybuttons (25), plural light source assembly (19) and plural sensor assembly (21). Each light source on assembly (19) is exclusively and sequentially energized causing its light to be transmitted through the first light transmission member (13) to be split up and deflected downwardly by the surfaces (43) and then rightwardly by the surfaces (45) to emanate through the surfaces (47) to enter the surfaces (49) of the second light transmission member. Actuation of a keybutton (25) causes its associated interrupter (29) to assume a light blocking position between the first light transmission member (13) and a second light transmission member (15). Light passing through the second light transmission member (15) to the sensor array indicates that none of the interrupters (29) have blocked the light path. This geometrical arrangement provides N key rollover detection with phantom key lockout and the light transmission members (13, 15) may be made of a single part or a single part for each row or column. Such part…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.