Wacom Co., Ltd.

Hideki Johno

Azuma Murakami

Yoichi Tuchida

Teruyoshi Hagiwara

A coordinates input apparatus has a tablet including X- and Y-direction position detecting portions having a multiplicity of loop coils arranged in parallel with one another in X- and Y-directions, respectively, the X- and Y-direction position detecting portions being superposed one on the other. The apparatus also has a position appointing device incorporating a tuning circuit capable of making resonance with electric wave produced from one of the loop coils. The loop coils are successively selected in a one-by-one fashion and an A.C. signal of a predetermined frequency is supplied to the thus selected loop coil. The electric wave causes a tuning of the tuning circuit in the position appointing device so that a voltage of a frequency substantially the same as the above-mentioned predetermined frequency is generated in the loop coil which is near the position appointing device. The position appointed by the position appointing device is therefore detected by sensing the induced voltage of a frequency substantially equal to the predetermined frequency of the A.C. voltage, through a processing by a suitable processing device. Since the position appointing device need not be connected to any stationary portion of the apparatus, the coordinates data can be input with a high degree of maneuverability and with a distinguished precision. It is also possible to display the data input through the position appointing device or the data transmitted thereto through a transmission line.

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Saitama, Japan

Hideki Johno