Apparatus and method for delivering power to a contactless portable data device
US5905372A · kind A · utility
53Cited by
5References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1997 |
| Grant date | May 18, 1999 |
| Priority date | — |
| Expiry date | Dec 17, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B5/79
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A terminal device powers a portable data device by transmitting in two modes of operation. In a first mode of operation, the terminal transmits to the portable data device a power signal at a first level and a data signal using a first modulation format and a first bit rate. In a second mode of operation, the terminal transmits to the portable data terminal a power signal at a second level and a data signal using a second modulation format and a second bit rate. The terminal determines a requirement to change modes of operation, and changes modes in response to changing power requirements of the portable data device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.