Pulse modulated infrared data communications link
First Claim
1. A method for communicating a biphase modulated signal having bit-cell and mid-cell transitions across an optical data link comprising:
- receiving said biphase modulated signal at a line receiver on a serial data line;
encoding each bit-cell and mid-cell transition of said biphase modulated signal to a narrow unidirectional pulse of a pulse modulated signal;
driving an optical transmitter with said pulse modulated signal to produce a pulsed optical signal;
receiving said pulsed optical signal at an optical receiver;
converting said received optical pulses to a pulsed electrical signal;
decoding said pulsed electrical signal as a biphase modulated signal; and
sending said biphase modulated signal on a serial data line by a line driver.
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Accused Products
Abstract
A pulse modulated infrared data communications link including a transmitter and receiver in which the data to be sent is encoded as a biphase modulated signal having bit-cell and mid-cell transitions. Each transition is encoded as a narrow pulse in a pulse modulated signal. The pulse modulated signal is used to activate an infrared optical transmitter for generating pulsed optical signals. At a receiver, an optical detector converts pulsed optical signals into pulsed electrical signals. The pulsed electrical signals are amplified and filtered and evaluated by a comparator to generate a pulsed digital signal. The pulsed digital signal is processed by a logic circuit to generate a biphase encoded signal for transmitting on a serial data line.
32 Citations
1 Claim
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1. A method for communicating a biphase modulated signal having bit-cell and mid-cell transitions across an optical data link comprising:
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receiving said biphase modulated signal at a line receiver on a serial data line; encoding each bit-cell and mid-cell transition of said biphase modulated signal to a narrow unidirectional pulse of a pulse modulated signal; driving an optical transmitter with said pulse modulated signal to produce a pulsed optical signal; receiving said pulsed optical signal at an optical receiver; converting said received optical pulses to a pulsed electrical signal; decoding said pulsed electrical signal as a biphase modulated signal; and sending said biphase modulated signal on a serial data line by a line driver.
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Specification
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- Resources
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Current AssigneeApple Inc.
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Original AssigneeApple Computer Incorporated (Apple Inc.)
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InventorsTonomura, Kihachiro
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Primary Examiner(s)Coles, Sr., Edward L.
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Assistant Examiner(s)NEGASH, KINFE MICHAEL
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Application NumberUS07/709,749Time in Patent Office721 DaysField of Search359/154, 359/142, 359/181, 359/182, 359/184-186, 359/118, 375/55, 375/87, 375/37, 332/100, 332/108, 332/112, 332/119, 341/70-71, 360/44US Class Current398/189CPC Class CodesH04B 10/508 Pulse generation, e.g. gene...H04B 10/524 Pulse modulationH04L 25/4902 Pulse width modulation; Pul...H04L 25/4904 using self-synchronising co...
