Device and method for detecting position of object and image display system having such device

An object position detecting device for detecting a position of an object, the object position detecting device comprising:

• a touch film;
• a first electrode set disposed under the touch film and including multiple first electrodes that are parallel with each other and run in a first direction, wherein at least one of the first electrodes is subject to a capacitance change when the object approaches the touch film, the first electrodes of the first electrode set are divided into multiple first electrode groups, and each first electrode group includes more than one of the first electrodes that are parallel with and connected with each other;
• a second electrode set disposed under the touch film and including multiple second electrodes that are parallel with each other and run in a second direction, wherein at least one of the second electrodes is subject to a capacitance change when the object approaches the touch film, the second electrodes of the second electrode set are divided into multiple second electrode groups, and each second electrode group includes more than one of the second electrodes that are parallel with and connected with each other;
• and
• a sensing and computing circuit electrically connected to the first electrode set and the second electrode set for sensing first equivalent capacitance values of the first electrode groups and second equivalent capacitance values of the second electrode groups, and calculating first position information of the object according to the first equivalent capacitance values and the second equivalent capacitance values.