Light guide
US5083240A · kind A · utility
38Cited by
2References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 1, 1991 |
| Grant date | Jan 21, 1992 |
| Priority date | — |
| Expiry date | May 1, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2219/0622
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A light guide for illuminating a keyboard or keypad from behind comprises a transparent grid-like plate having an array of apertures in each of which is accommodated a respective key of the keyboard/keypad. Means are provided for reflecting light from an external source into the plan of the light guide. The individual apertures are surrounded by an upstanding rib formed integrally with the light guide. The top (outer) face of the rib is rendered optically imperfect to promote the escape of light thereform, thus providing an illuminated ring around each key.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.