Improved multi-touch detection in a touch system

• Main Authors: OHLSSON, NICKLAS, JUHLIN, PETER, WALL, HENRIK, WALLANDER, MATS PETTER, JOHANSSON, ANDREAS, CHRISTIANSSON, TOMAS
• Format: Patent
• Language: Chinese; English
• Published: 16.08.2013
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; PHYSICS

Multi-touch sensitivity is enabled using a touch system that comprises a panel configured to conduct signals, e.g. by FTIR, from a plurality of incoupling points to a plurality of outcoupling points, thereby defining detection lines across the panel between pairs of incoupling ad outcoupling points. A signal processor operates in a repeating sequence of iterations to obtain (50) a current signal value for each detection line, and generate (53, 53') a first interaction pattern and a second interaction pattern as a function of the current signal values, such that the first and second interaction patterns are reconstructed two-dimensional distributions of local interaction with the conducted signals across the surface portion, and represent changes in interaction on different time scales. Thereby, the movement of an object will affect how it is represented in each of the first and second interaction patterns. Touch detection may be improved by proper selection of the time scales and combined analysis (56) of the