| 摘要 |
PURPOSE:To increase transfer speed, and to transmit large quantity of data, etc., by transmitting simultaneously plural subcarriers. CONSTITUTION:A transmitter can be divided roughly into an oscillation circuit 2, a demultiplying stage 3, a controller 4, a key scan input circuit 5, LED drive circuits 6, 7, infrared LEDs 8, 9 and a key matrix 10. On the way of this demultiplying stage 3 frequencies f1, f2, corresponding to the subcarriers are taken out, and a data line corresponding to a key pushed by the key matrix 10 is generated by the controller 4, and modulated by the subcarriers f1, f2, and transmitted as the infrared ray by flowing a large current in the infrared LEDs 8 and 9 by the LED drive circuits 6, 7. Thus, the transfer can be speeded up.
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