Position code

US6667695B2 · kind B2 · utility

Assignee

• Anoto AB · SE

Inventors

• Mats Petter Pettersson · Lund, SE
• Andreas Björklund · Lund, SE

Key dates

• Filing date: Jun 25, 2002
• Grant date: Dec 23, 2003
• Expiry date: Jun 25, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F3/0321
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

In a method for position coding, positions are coded in a first dimension on a surface in accordance with a primary number sequence that has the property that the place in the primary number sequence of each partial sequence of a first predetermined length is unambiguously determined. Each position in the first dimension is coded by one of the partial sequences. The primary number sequence is built up of at least two secondary number sequences that have a smaller base than the base of the primary number sequence and that are used for determination of the partial sequences of the primary number sequence which correspond to the positions in the first dimension. This makes possible, among other things, realization of the method in devices with limited memory capacity, as the secondary number sequences require less memory in total than the primary number sequence. The secondary number sequences can also be used for decoding the position code.