Optical touch screens

US9678601B2 · kind B2 · utility

Assignee

• Neonode Inc. · SE

Inventors

• Robert Pettersson · Åtvidaberg, SE
• Per Rosengren · Solna, SE
• Erik Anders Claes Rosengren · Stockholm, SE
• Stefan Holmgren · Sollentuna, SE
• Lars Sparf · Ljungby, SE
• Richard Berglind · Ayacucho, PE
• Thomas Eriksson · Stockholm, SE
• Karl Erik Patrik Nordström · Huddinge, SE
• Gunnar Martin Fröjdh · Tyresö, SE
• Xiatao Wang · Lidingö, SE
• Remo Behdasht · Chatswood, AU

Key dates

• Filing date: May 31, 2015
• Grant date: Jun 13, 2017
• Expiry date: Aug 7, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F2203/04109
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Activating a plurality of light emitters and light detectors around a screen, each emitter-detector pair corresponding to a light path crossing the screen, wherein some of the light paths are blocked when one or more objects touch the screen, providing a look-up table, listing, for each cell from a plurality of cells, those light paths that traverse that cell when no object is touching the screen, wherein the cells partition the screen, for each cell: accessing the look-up table to identify those light paths that traverse that cell, determining whether the thus-identified light paths are blocked during the activating and, if affirmative, recognizing that cell as being a touched cell, and combining adjacent touched cells into a common touch location, thereby calculating one or more touch locations wherein each touch location is a combination of one or more constituent touched cells.