Pen state detection circuit and method, and input system

Abstract

Provided is a pen state detection circuit for detecting a state of an electronic pen based on a signal distribution detected by a touch sensor including a plurality of sensor electrodes arranged in a plane shape, the electronic pen including at least one electrode, the pen state detection circuit, in operation, acquires, from the touch sensor, a first signal distribution and a second signal distribution, generates a two-dimensional signal distribution by synthesizing the first signal distribution and second signal distribution, or generates a two-dimensional feature distribution by synthesizing a first feature distribution relating to a shape of the first signal distribution and a second feature distribution relating to a shape of the second signal distribution, and estimate a position indicated by the electronic pen or a posture of the electronic pen from the two-dimensional signal distribution or two-dimensional feature distribution.