Keyboard having visible and invisible states
US5544020A · kind A · utility
27Cited by
4References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1993 |
| Grant date | Aug 6, 1996 |
| Priority date | — |
| Expiry date | Nov 12, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D11/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A chart recorder or other instrument has a window 10 within which is a key panel 1 composed of materials which are transparent in normal conditions. Incorporated in or associated with the individual elements of the key panel are display elements 22 applied to the transparent window material 20. The display elements are normally transparent but become visible, for example by fluorescence, when illuminated by radiation transmitted through the body of the transparent window material 20, rendering the key panel visible when needed for use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.