Portable wireless communication device having an extendible section
US6243595A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1998 |
| Grant date | Jun 5, 2001 |
| Priority date | — |
| Expiry date | Jun 16, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M2250/22
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A portable cellular telephone comprising a main body for housing at least a microcontroller, a display screen, an audio receiver and a microphone. An extendible section that houses a number of function keys such as the standard telephone keys, slides out of the main body to expose the display screen in its entirety. The extendible section also includes LED's to back light the keys when desirable. The electrical connections between the extendible section and the main body are achieved through wiper contacts in the main body that slide over conductive strips on the under surface of the extendible section. The keys in the extendible section are each connected to resistors of different values, these resistor/key combinations are all connected in parallel to two conductive strips. A resistor bridge is formed by connecting a resistor in the main body to the resistor key combinations. The voltage change at the junction between the resistor and the combinations is detected to sense the closure of a key, and the voltage value is used to identify the key that is closed. The device also detects when the extendible section is in the open or closed positions. The extendible section is mounted s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.