Optical touch system and hovering identification method thereof

A hovering identification method of an optical touch system, the optical touch system comprising a plurality of image sensors respectively configured to capture an image frame looking across a touch surface, the hovering identification method comprising:

• calculating, using a calculation unit, a coordinate of at least one object and an operating depth of the at least one object corresponding to each of the image sensors according to the image frame;
• defining one of the image sensors as an operable image sensor when the coordinate is within an operable range of the one of the image sensors;
• comparing, using an identification unit, the operating depth of the operable image sensor associated with each of the object with at least one depth threshold;
• and
• identifying a hovering state of each of the object according to a count value of the operable image sensor with the associated operating depth exceeding the depth threshold corresponding to each of the object.

An optical touch system, comprising:

• a touch surface for an object operating thereupon;
• a plurality of image sensors, each of the image sensors being configured to capture an image frame looking across the touch surface;
• a calculation unit configured to calculate a coordinate of the object and an operating depth of the object corresponding to each of the image sensors according to the image frame;
• and
• an identification unit configured to
• increase a count value when the coordinate is within an operable range of one of the image sensors and the operating depth corresponding to the one of the image sensors exceeds a depth threshold, and
• identify an operating state of the object according to the count value.