Illuminable push button switching unit
US5655826A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1996 |
| Grant date | Aug 12, 1997 |
| Priority date | — |
| Expiry date | Mar 22, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2219/052
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved push button switching unit is proposed of which the indicia on the key top is recognizable even in a dark place. Namely, a phosphorescent layer emitting phosphorescence even in a dark place is formed on the upper surface of the key top to provide recognizability of the indicia and further the switching unit is provided with a light sensor means and a light source which is lighted when the ambient lightness is low as detected by the sensor means. When the switching unit is used continuously in a dark place, the light source repeats cycles of a lighting period, in which the phosphorescent layer accumulates the energy of light, and a dark period, in which the phosphorescent layer emits phosphorescence by means of the accumulated energy, so that the power consumption for lighting the light source can be saved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.