Position detection method of pointer and sensor controller

A sensor controller that uses a sensor including a plurality of sensor electrodes to detect a position of a passive pointer that does not transmit a signal and a position of an active pen that transmits a pen signal from a pen electrode provided on a front end part, the sensor controller comprising:

• a processor;
• and
• a memory storing instructions that, when executed by the processor, cause the sensor controller to:
• decode the pen signal to acquire a pen pressure value indicating pressure applied to a pen tip of the active pen;
• enter a first operation mode of detecting, in time division, the position of the active pen and the position of the passive pointer on a panel surface when the pen pressure value indicates that the pen tip is not in contact with the panel surface;
• and
• enter a second operation mode of detecting the position of the active pen on the panel surface and not detecting the position of the passive pointer on the panel surface when the pen pressure value indicates that the pen tip is in contact with the panel surface;
• determine whether the pen signal is detected;
• enter any one of the first and second operation modes when the sensor controller determines that the pen signal is detected;
• and
• enter a third operation mode of detecting, in time division, the position of the active pen and the position of the passive pointer on the panel surface, with a detection frequency of the position of the passive pointer higher than that in the first operation mode, when the sensor controller determines that the pen signal is not detected.