ELECTRONIC TERMINAL EQUIPMENT, PEN DEVICE, ELECTRONIC TERMINAL SYSTEM, AND INFORMATION TRANSMISSION METHOD

摘要

PROBLEM TO BE SOLVED: To notify a user of an event such as a decrease in the residual amount of a battery which has occurred in a pen device to be used for inputting position information to electronic terminal equipment by using a simple transmission system without providing any display part or additional transmission means in the pen device.SOLUTION: The electronic terminal equipment includes: a reception part for receiving an electromagnetic wave to be transmitted from a pen device to generate a reception signal; a detection part for detecting the amplitude or frequency of the reception signal; a position measurement part for measuring the relative position of the pen device to the electronic terminal equipment on the basis of the amplitude of the reception signal; a determination part for determining whether or not the rate of change of the amplitude or frequency of the reception signal per fixed time is larger than a predetermined value; and a notification part for, when it is determined that the rate of change of the amplitude or frequency of the reception signal per fixed time is larger than the predetermined value, notifying a user of an event which has occurred in the pen device, or changes the display system of the position of the pen device in accordance with the event which has occurred in the pen device.