公开(公告)号：US20170293397A1

公开(公告)日：2017-10-12

申请号：US15480679

申请日：2017-04-06

Applicant: ROHM CO., LTD.

Inventor： Hirotoshi USUI ,  Naoki TADA ,  Hiroshi YAMASHITA

IPC: G06F3/041

CPC classification number: G06F3/0418 ,  G02F1/13338 ,  G06F3/045 ,  G06F2203/04104

Abstract: A control circuit of a touch panel is disclosed. The touch panel includes first and second terminals drawn from a first resistive film; and third and fourth terminals drawn from a second resistive film. The control circuit includes a coordinate detection circuit configured to generate an impedance detection signal for an impedance of the touch panel and a voltage detection signal for at least one of voltages of the first to fourth terminals, which are used for generating a coordinate touched by a user. The control circuit further includes a memory configured to store initial data corresponding to an initial state impedance of at least one predetermined path of the touch panel. A calibration circuit of the control circuit acquires an operation state impedance of the path and calibrate the coordinate detection circuit based on detection data corresponding to the operation state impedance and the initial state impedance.