Optical transceiver with improved range and data communication rate
First Claim
1. An optical communication device for receiving serial communication at various selectable baud rates, comprising:
- a photo diode for receiving light pulses and converting the light pulses into electrical pulses;
a first bipolar transistor having its base coupled to the photo diode for amplifying the electrical pulses;
a high pass filter for filtering out lower frequency amplified electrical pulses, the filter comprising;
a second bipolar transistor having its collector coupled to the base of the first transistor and the photo diode, and having its base coupled to the emitter of the first transistor; and
a capacitor coupled at one end to the emitter of the first transistor and the base of the second transistor and coupled at the other end to ground; and
a converter for converting the filtered pulses into digital pulses having predetermined digital signal levels.
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Accused Products
Abstract
An IR transceiver for use in low-power, low cost environments such as portable computers and hand-held calculators. The transceiver can transmit data at higher, selectable baud rates and at greater distances than previously possible. On the transmitting side the transceiver elements include a serial interface device, encoder circuitry and an IR transmitter with LEDS having fast turn-on and turn-off times. On the receiving side are decoder circuitry coupled to the serial interface device and an IR receiver designed specifically for a photo diode. A baud rate generator provided by the serial interface device sets the baud rate in the encoding and decoding circuitry. The receiver portion of the IR transceiver automatically sets itself to the baud rate of received data. Because of the baud rate selectability, the IR transceiver is compatible with prior IR transceivers that are limited to fixed baud rates.
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Citations
21 Claims
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1. An optical communication device for receiving serial communication at various selectable baud rates, comprising:
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a photo diode for receiving light pulses and converting the light pulses into electrical pulses; a first bipolar transistor having its base coupled to the photo diode for amplifying the electrical pulses; a high pass filter for filtering out lower frequency amplified electrical pulses, the filter comprising; a second bipolar transistor having its collector coupled to the base of the first transistor and the photo diode, and having its base coupled to the emitter of the first transistor; and a capacitor coupled at one end to the emitter of the first transistor and the base of the second transistor and coupled at the other end to ground; and a converter for converting the filtered pulses into digital pulses having predetermined digital signal levels. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of receiving optically serial communication at various baud rates, comprising the following steps:
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providing a photo detector for receiving light pulses and converting the light pulses to electrical pulses; amplifying the electrical pulses; filtering lower frequency electrical pulses out of the electrical pulses by feeding back the lower frequency pulses to the amplifier; generating a clock signal at one of a number of baud rates selectable by a control signal; with the clock signal generated at the selected baud rate, converting the electrical pulses into a stream of bits having the selected baud rate. - View Dependent Claims (9)
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10. An optical communication transceiver for receiving and sending serial communication at various selectable baud rates, comprising:
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(a) a serial interface device for transmitting and receiving a serial bit stream at a baud rate selectable by a control signal; (b) an encoder for encoding the serial bit stream from the serial interface device into electrical pulses, the serial bit stream having a baud rate set by the serial interface device; (c) an optical transmitter coupled to the encoder for transforming the electrical pulses of the encoder into light pulses for transmission; (d) an optical receiver for receiving light pulses and transforming them into electrical pulses; and (e) a decoder for decoding the electrical pulses from the optical receiver into a serial bit stream for the serial interface device, the serial bit stream having a baud rate set by the serial interface device. - View Dependent Claims (11, 12)
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13. A method of communicating information optically, comprising:
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electronically selecting a baud rate; generating a serial bit stream at the selected baud rate, each bit occupying its full bit time; encoding the serial bit stream into electrical pulses, each pulse occupying a fraction of the serial bit time; and driving an LED with the electrical pulses to generate light pulses. - View Dependent Claims (14)
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15. An optical communication device for receiving serial communication at various baud rates, comprising:
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a photo detector for receiving light pulses and converting the light pulses to electrical pulses; a converter for converting the electrical pulses into digital pulses; a baud rate generator for generating a clock signal at one of a number of baud rates selectable by a control signal; and means responsive to the clock signal generated at the selected baud rate for converting the digital pulses into a stream of bits having the selected baud rate. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification