Patent ID: 6639585
Filing Date: 2003-10-28
Classification: G06F

Abstract:
A coordinate reading device for reading a coordinate of a position of a target member, which generates an alternating magnetic field, the coordinate reading device comprising:a coordinate input sheet that has a coordinate input surface defining a coordinate of a target member that generates an alternating magnetic field; a loop-wire attaching member that is provided below the coordinate input sheet and that has a plurality of loop wires, each loop wire being capable of producing a signal in response to the alternating magnetic field; a detection unit that detects the signals from the plurality of loop wires; a coordinate determination unit that determines a coordinate of the position of the target member based on the signal from at least one of the loop wires that is selected for coordinate determination; and a correction unit that controls the coordinate determination unit to determine a corrected coordinate of the position of the target member based on a relationship between a predetermined reference value and the value of the signal from at least one of the plurality of loop wires that is selected for coordinate correction; wherein the plurality of loop wires include one correction loop wire that is located on a predetermined position on the loop-wire attaching member and that is used exclusively for the correction operation, wherein the correction unit compares the value of the signal from the correction loop wire with the predetermined reference value, and controls the coordinate determination unit to determine the corrected coordinate of the position of the target member based on the compared result.