Digital pen using speckle tracking
US6686579B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 2000 |
| Grant date | Feb 3, 2004 |
| Priority date | — |
| Expiry date | Apr 26, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A digital pen that has an ink writing tip includes a laser on a pen body that directs light toward paper across which the writing tip is stroked. A CMOS camera or CCD is also mounted on the pen body for detecting reflections of the laser light, referred to as “speckles”. A processor in the pen body determines relative pen motion based on the speckles. A contact sensor such as an FSR on the pen body senses when the tip is pressed against the paper, with positions being recorded on a flash memory in the pen body when the contact sensor indicates that the pen is against the paper. The memory can be later engaged with a handwriting recognition device to correlate the positions to alpha-numeric characters. Ordinary paper can be used, but, if desired, special bar-coded paper can also be used, so that the recorded positions can be tagged with a page number, form field, and absolute position on the page.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.