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Low power optical transceiver for portable computing devices

  • US 5,075,792 A
  • Filed: 03/20/1989
  • Issued: 12/24/1991
  • Est. Priority Date: 03/20/1989
  • Status: Expired due to Term
First Claim
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1. Apparatus for optical communication, comprising,a data processor for processing information as the information is transmitted or received at a given bits per second rateand for formatting the information for transmission from a nonreturn to zero bit format to a return to zero bit format and for reception from a return to zero bit format to a nonreturn to zero bit format;

  • andan optical transceiver coupled to the data processor for transmitting and receiving the information so formatted, the optical transceiver comprising an IR transmitter and IR receiver, the IR receiver further comprising;

    a phototransistor for receiving an IR signal;

    a first transistor having its collector coupled to the base of phototransistor and its base coupled to the emitter of the phototransistor for compensating for the effects of ambient light on the conducting threshold of the phototransistor;

    a capacitor coupled between the base of the first transistor and ground for filtering the effects of the received IR signal from the effects of ambient light on the operation of the first transistor; and

    a second transistor having its base coupled to the emitter of the phototransistor and base of the first transistor for converting the received IR signal to a corresponding signal interpretable by the data processor.

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