Switch device and electronic instruments equipped with the switch device
US5612931A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 1995 |
| Grant date | Mar 18, 1997 |
| Priority date | — |
| Expiry date | Jul 5, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2300/054
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
When an electronic instrument has taken a predetermined attitude, an attitude-detecting switch incorporated in the instrument detects the attitude, and outputs a switch signal to a CPU. The CPU, in turn, drives a lighting device for lighting a liquid crystal display device. The lighting device is driven, for example, only when a predetermined number of pulses of the switch signal are generated within a predetermined period of time, or only when the switch signal has continued for a predetermined period of time or more. Thus, there are cases where the lighting device is not driven irrespective of the generation of the switch signal. As a result, the lighting device is prevented from operating so often, and hence the life of its battery is lengthened.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.