Lighted telephone dial
US4349705A · kind A · utility
33Cited by
7References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 6, 1981 |
| Grant date | Sep 14, 1982 |
| Priority date | — |
| Expiry date | May 6, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2219/062
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A pushbutton dial having pushbuttons arranged in three columns and four rows has the buttons illuminated by four LED's positioned in a light-guide plate having apertures which surround the pushbuttons. The LED's are in recesses at intersections of the outer columns and top and bottom rows, each recess between four adjacent apertures. Guide grooves at the edges of the plate redirect light issuing from the LED's and passing between apertures. The plate is transparent and the buttons translucent, the buttons being illuminated from all round their peripheries.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.