Position sensing method for use in coordinate input apparatus

In a coordinate sensing apparatus having a sensor section which forms a sensor plane and consists of a plurality of sensor coils arranged side by side along coordinate axes, and a position indicator housing at least a coil, a position sensing method which obtains at least a coordinate value of a position indicated by the position indicator and an inclination of the position indicator in relation to the sensor plane by the use of a value of a sensing signal including a main peak value and at least one sub-peak value, both being obtained from interactive action between the position indicator and a specified sensor coil of the group of sensor coils, wherein the position sensing method comprises:

• a SECTOR SCAN step of carrying out scanning along one specific coordinate axis of the coordinate axes to obtain at least
• (1) sensing signal from a group of main-peak selection coils including a main sensor coil which provides the main peak value and at least the number of sensor coils required for calculating the coordinate value by means of interpolation calculation,
• (2) a first sensing peak value from a first sub-sensor coil which provides a first sub-peak value on the left side of the main peak value with respect to the specific coordinate axis, and
• (3) a second sensing peak value from a second sub-sensor coil which provides a second sub-peak value on the right side of the main peak value with respect to the specific coordinate axis;
• and
• a calculation step of, calculating the coordinate value by means of interpolation calculation using the sensing signals obtained from the group of main-peak selection sensor coils, and also calculating the inclination using the first sensing peak value obtained from the first sub-sensor coil and the second peak value obtained from the second sub-sensor coil, at the time of sector scanning.