Method, apparatus, computer program and storage medium for recording a movement of a user unit
US7865043B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2004 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Sep 6, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V10/19
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A position code is recorded by capturing a sequence of images while writing on the base with a user unit. The position code may be decoded to a sequence of absolute positions reflecting the movement of the user unit over the base. If the position code in any image is not sufficiently recorded, e.g. because it is obscured by other graphics on the base, the spatial relationship of the image to another image in the sequence is determined. If the position code in this other image in the image sequence is decodable to an absolute position, the absolute position of the image in which the position code is not decodable could nevertheless be determined by using the spatial relationship. In this way the movement of the user unit can be recorded even though the position code is obscured, which could be the case when the same printing ink is used for both the position code and other graphics on the base.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.