An input assistance device has a rotation support body having a central axis, an attachment mechanism that removably attaches the rotation support body to the panel surface of a sensor panel so that the central axis is along a direction perpendicular to the panel surface, and a rotational part supported by the rotation support body so as to be rotatable around the central axis. At least the side surface of the rotational part is formed from a conductive material. Conductive areas electrically connected to the side surface are allocated in part of a surface of the rotational part, the surface facing the panel surface.

An input assistance device has a rotation support body having a central axis, an attachment mechanism that removably attaches the rotation support body to the panel surface of a sensor panel so that the central axis is along a direction perpendicular to the panel surface, and a rotational part supported by the rotation support body so as to be rotatable around the central axis. At least the side surface of the rotational part is formed from a conductive material. Conductive areas electrically connected to the side surface are allocated in part of a surface of the rotational part, the surface facing the panel surface.

An input assistance device has a rotation support body having a central axis, an attachment mechanism that removably attaches the rotation support body to the panel surface of a sensor panel so that the central axis is along a direction perpendicular to the panel surface, and a rotational part supported by the rotation support body so as to be rotatable around the central axis. At least the side surface of the rotational part is formed from a conductive material. Conductive areas electrically connected to the side surface are allocated in part of a surface of the rotational part, the surface facing the panel surface.

A control section allows a screen of a display section to display a plurality of numeric keys, detects a touch gesture on the individual numeric key through a touch panel to allow an input of a numeric number corresponding to the numeric key subjected to the touch gesture, and detects an action on each of hard keys to accept an instruction to perform a function corresponding to the hard key subjected to the action. When a predetermined action is performed on one or more individuals of the hard keys, the control section assigns numeric numbers to the respective hard keys and detects an action on the individual hard key to allow an input of the numeric number corresponding to the hard key subjected to the action.