Cordless digitizer stylus status encoding and transmission scheme
US5247138A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 8, 1991 |
| Grant date | Sep 21, 1993 |
| Priority date | — |
| Expiry date | Nov 8, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/03545
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a cordless digitizing system wherein a cordless stylus having a manually operable button thereon transmits positional pulses to a tablet at a carrier frequency this invention is apparatus for transmitting status information about the button to the tablet. There is first status logic associated with the stylus for sensing the present status of the button and for encoding and transmitting the present status of the button as a binary 1 or 0 employing a first unique and recognizable sequence of carrier frequency cycles as a binary "1" and a second unique and recognizable sequence of carrier frequency cycles as a binary "0". Then, there is second status logic included in association with the tablet for recognizing the first unique and recognizable sequence of carrier frequency cycles to be a binary "1", for recognizing the second unique and recognizable sequence of carrier frequency cycles to be a binary "0", and for determining the present status of the button therefrom. The status of multiple buttons on the stylus is transmitted in the same manner by assigning the buttons positions in a binary data stream.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.