| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably detect the switch pushing states regardless of the variance, etc., of frequency by changing periodically the oscillation frequency according to the pushing states of plural switches of a coordinate designation tool and detecting the switch pushing states of the coordinate designation tool based on the detected frequency change state. SOLUTION: A coordinate designation pen 1 includes an oscillator which generates the electric signals, and a stylus set at the tip part of the pen 1 serves as a signal transmission electrode 3 to transmit the electric signals to its periphery. The oscillator of the pen 1 periodically changes the oscillation frequency according to the pushing states of plural switches of the pen 1, and these switch pushing states are detected based on the changing state of frequency that is detected by a frequency detection means. A coordinate input device of such a constitution can satisfactorily discriminate the different frequency levels and also their periodical changing states. Thus, the pushing states of many switches can be discriminated in a stable state.</p> |
