Digital infrared communications system with edge detection
First Claim
1. Apparatus for detecting a digital signal representing digital data comprising:
- first means for providing an input signal including the digital signal and noise which has a larger magnitude than the digital signal and a slow rate of change relative to the digital signal'"'"'s rise time;
second means coupled to the first means for deriving a signal indicating the digital data from the input signal; and
third means coupled to the second means for deriving the digital data from the signal indicating the digital data,the apparatus being characterized bymeans in the second means for receiving the input signal, detecting edges of the digital signal therein, and outputting an edge signal indicating each detected edge'"'"'s direction as the signal indicating the digital data to the third means.
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Accused Products
Abstract
A low-cost, low-power infrared digital communications system. The system overcomes the problem of infrared noise from interior lighting without using either a high-power infrared source or upmodulation of the source. The system includes an infrared collector which uses a non-directional concentrator to concentrate the infrared radiation and a circuit which detects the digital infrared signal in the noise by detecting the edges of the digital infrared signal. Devices in the system need not be aimed at each other, but need only be in line of sight of each other. The preferred embodiment employs the digital infrared signals to communicate between a set of digital devices and a breaker box connected to the telephone network.
20 Citations
31 Claims
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1. Apparatus for detecting a digital signal representing digital data comprising:
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first means for providing an input signal including the digital signal and noise which has a larger magnitude than the digital signal and a slow rate of change relative to the digital signal'"'"'s rise time; second means coupled to the first means for deriving a signal indicating the digital data from the input signal; and third means coupled to the second means for deriving the digital data from the signal indicating the digital data, the apparatus being characterized by means in the second means for receiving the input signal, detecting edges of the digital signal therein, and outputting an edge signal indicating each detected edge'"'"'s direction as the signal indicating the digital data to the third means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A digital infrared communications system comprising
a transmitter for emitting a digital infrared signal representing digital data and a receiver including infrared collector means responsive to infrared radiation including the digital infrared signal and noise which has a larger magnitude than the digital infrared signal and a slow rate of change relative to the digital infrared signal'"'"'s rise time, the infrared collector means providing an input signal having a digital signal portion and a noise portion, digital signal detection means coupled to the infrared collector means for deriving a signal indicating the digital data from the input signal; - and
digital data deriving means coupled to the digital signal detection means for deriving the digital data from the signal indicating the digital data, the digital infrared communications system being characterized in that; the digital signal detection means includes means for detecting edges of the digital signal portion in the input signal and outputting an edge signal indicating the direction of each detected edge as the signal indicating the digital data. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 23)
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18. Apparatus for communicating using a digital infrared signal, the apparatus comprising at least a receiver including
infrared collector means for responding to infrared radiation including the digital infrared signal and noise which has a larger magnitude than the digital signal and a slow rate of change relative to the digital signal'"'"'s rise time, the infrared collector means providing an input signal having a digital portion and a noise portion, digital signal detection means coupled to the infrared collector means for deriving a signal indicating the digital data from the input signal; - and
digital data deriving means coupled to the digital signal detection means for deriving the digital data from the signal indicating the digital data, the apparatus being characterized by; means in the digital signal detection means for detecting edges of the digital signal portion in the input signal and outputting an edge signal indicating each detected edge'"'"'s direction as the signal indicating the digital data to the third means. - View Dependent Claims (19, 20, 21, 22)
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24. Apparatus for coupling a digital device to a network by means of digital infrared signals, the apparatus comprising:
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a breaker box for interfacing between the network and the digital device, transmitters on the breaker box and the digital device for transmitting the digital infrared signals, and receivers on the breaker box and the digital device for receiving the digital infrared signals, each receiver including infrared collector means for responding to infrared radiation including the digital infrared signal and noise which has a larger magnitude than the digital infrared signal and a slow rate of change relative to the digital infrared signal'"'"'s rise time, the infrared collector means providing an input signal which has a digital signal portion and a noise portion, digital signal detection means coupled to the infrared collector means for deriving a signal indicating the digital data from the input signal; and digital data deriving means coupled to the digital signal detection means for deriving the digital data from the signal indicating the digital data, the digital infrared communications system being characterized in that; the digital signal detection means includes means for detecting edges of the digital signal portion in the input signal and outputting an edge signal indicating the direction of each detected edge as the signal indicating the digital data. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31)
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Specification