Optical touch system, method of touch detection, and computer program product

A method of touch detection, configured to determine a group transformation when two groups of objects approach to or touch a base plane, the method of touch detection comprising:

• providing at least one light beam, wherein the at least one light beam is propagated in front of the base plane;
• detecting a space in front of the base plane from a first detection position to generate a first signal;
• detecting the space in front of the base plane from a second detection position to generate a second signal;
• determining at least one first portion of the first signal corresponding to the two groups of the objects and at least one second portion of the second signal corresponding to the two groups of the objects when the two groups of the objects approach to or touch the base plane;
• converting the at least one first portion and the at least one second portion into a plurality of possible touch regions in a two-dimensional space;
• determining the group transformation according to positions corresponding to at least a part of the possible touch regions;
• and
• determining whether the number of approaching or touching positions of the two groups of the objects on the base plane is greater than or equal to 5, and if yes, determining that the two groups of the objects approach to or touch the base plane, and determining the at least one first portion of the first signal corresponding to the two groups of the objects and the at least one second portion of the second signal corresponding to the two groups of the objects by using a clustering algorithm.

A computer program product, stored in a non-transitory computer readable storage medium for determining a group transformation when two groups of objects approach to or touch a base plane, the computer program product comprising:

• a first program instruction for providing at least one light beam, wherein the at least one light beam is propagated in front of the base plane;
• a second program instruction for detecting a space in front of the base plane from a first detection position to generate a first signal;
• a third program instruction for detecting the space in front of the base plane from a second detection position to generate a second signal;
• a fourth program instruction for determining at least one first portion of the first signal corresponding to the two groups of the objects and at least one second portion of the second signal corresponding to the two groups of the objects according to a clustering algorithm when the two groups of the objects approach to or touch the base plane;
• a fifth program instruction for converting the at least one first portion and the at least one second portion into a plurality of possible touch regions in a two-dimensional space according to a triangulation;
• and
• a sixth program instruction for determining the group transformation according to positions corresponding to at least a part of the possible touch regions.