Patent ID: 8720279

Claim:
An object detection device that detects whether an object is located between a frame and a movable object, which moves relative to the frame, the object detection device comprising: three or more first electrodes arranged on at least one of the frame and the movable object; an electric field measurement unit connected to the first electrodes to measure the capacitance detected by any of the first electrodes and by any combination of the first electrodes; a control circuit connected to the electric field measurement circuit to specify which of the first electrodes and which combinations of the first electrodes are to be used by the electric field measurement unit for measuring capacitance based on movement of the movable object, wherein changing the specified first electrodes used for measuring capacitance varies the sensitivity of the electric field measurement circuit; and a position detecting circuit connected to the control circuit to detect the position of the movable object, wherein the control circuit specifies which of the first electrodes to use for measuring capacitance based on the position of the movable object.