Status identification system for position indicator

Abstract

Abstract PURPOSE:To improve the operability of a position indicator and to identify status by allowing an antenna coil to radiate a radio wave, allowing it to receive a reflected radio wave from a tuning circuit of the position indicator when the radio wave radiation is stopped and detecting the loss from the attenuation. CONSTITUTION:An antenna coil 13 fitted to a main body 12 of a tablet 1 receives an AC signal of a prescribed frequency and radiates a radio wave. The radio wave is received by a tuning circuit 22 of an input pen 2 and the circuit 22 generates the induced voltage of nearly the same frequency as that of the signal fed to the oil 13. The voltage is attenuated gradually from the loss in the circuit 22 when the radio wave radiation is stopped from the coil 13, but the reflected ratio wave is radiated from the coil in the circuit 22 based on the current flowing to the circuit 22 in this case. The reflected radio wave is received by the coil 13 stopping the radiation of the radio wave and the induced voltage generated in the coil 13 shown the same attenuation as that of that of the induced voltage in the circuit 22. Thus, the loss in the tuning circuit is detected and the status of the position indicator is identified.

Inventors

• 👤 Tsugunari Yamanami
• 👤 山並　嗣也
• 👤 Toshiaki Senda
• 👤 仙田　聡明
• 👤 Toshihide Chikami
• 👤 敏秀 千頭

Bibliographic Details