Transmitter pen location system
US6335723B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1998 |
| Grant date | Jan 1, 2002 |
| Priority date | — |
| Expiry date | Oct 2, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0433
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A transmitter pen positioning system is provided, in which a pen, having multiple output elements, is used to accurately determine the location of the pointing tip of the pen, in relation to the writing area of a surface, such as a white board. The first output element, preferably an infrared transducer, transmits a first output signal from the transmitter pen. The second output element, preferably an ultrasonic transducer, transmits a second output signal, having a lower propagation velocity than the first output signal, from the transmitter pen to two or more receivers. In a basic embodiment, the first output signal arrives at one or more receivers generally concurrently. The second output signal, having a speed of propagation different from the speed of propagation of the first signal, is transmitted from the transmitter pen at a known time in relation to the first output signal, and arrives at each of the receivers at a time which is dependent on the velocity of the second signal and the distance between the transmitter pen and the receivers. The location of the pointing tip of the transmitter pen is then determined, by using the first signal as a boundary condition, by compari…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.