Infrared communications scheme
First Claim
1. A communications method for an infrared transmitting device having a light emitting diode (LED) comprising:
- ramping up at a constant rate the power of a carrier frequency signal applied to the LED in a given time interval to a given value, wherein the carrier frequency signal is a sine wave;
frequency modulating the carrier frequency signal with a data message for transmission by the LED after the power of the carrier frequency signal applied to the LED has been ramped up to the given value, wherein the data message is a digital signal; and
ramping down at a constant rate the power of the carrier frequency signal applied to the LED in a given time interval to a given value after the LED has transmitted the data message.
3 Assignments
0 Petitions
Accused Products
Abstract
Infrared communications scheme for an infrared transmitting device having a light emitting diode (LED) ramps up the power of a carrier frequency signal applied to the LED in a given time interval to a given value. The carrier frequency signal is then frequency modulated with a data message for transmission by the LED. The power of a DC signal applied to the LED may then be ramped up in a given time interval to a given value before the carrier frequency signal is modulated with a data message. After transmission of the data message, the power of the carrier frequency signal applied to the LED is ramped down in a given time interval to a given value. The power of the DC signal applied to the LED is then ramped down in a given time interval to a given value.
37 Citations
18 Claims
-
1. A communications method for an infrared transmitting device having a light emitting diode (LED) comprising:
-
ramping up at a constant rate the power of a carrier frequency signal applied to the LED in a given time interval to a given value, wherein the carrier frequency signal is a sine wave; frequency modulating the carrier frequency signal with a data message for transmission by the LED after the power of the carrier frequency signal applied to the LED has been ramped up to the given value, wherein the data message is a digital signal; and ramping down at a constant rate the power of the carrier frequency signal applied to the LED in a given time interval to a given value after the LED has transmitted the data message. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. An infrared transmitting device comprising:
-
a light emitting diode (LED); an oscillator for applying a carrier frequency signal to the LED, wherein the carrier frequency signal is a sine wave; a modulation ramp generator for ramping up at a constant rate the power of a carrier frequency signal applied to the LED in a given time interval to a given value; and a data terminal operable with the oscillator for frequency modulating the carrier frequency signal of the oscillator with a data message for transmission by the LED after the power of the carrier frequency signal applied to the LED has been ramped up to the given value, wherein the data message is a digital signal; wherein the modulation ramp generator ramps down at a constant rate the power of the carrier frequency signal applied to the LED in a given time interval to a given value after transmission of the data message by the LED. - View Dependent Claims (10, 11, 12, 13, 14)
-
-
15. An infrared communications system comprising:
-
a transmitter including a light emitting diode (LED), an oscillator for applying a sinusoidal carrier frequency signal to the LED, a modulation ramp generator for ramping up at a constant rate the power of a carrier frequency signal applied to the LED in a given time interval to a given value, and a data terminal operable with the oscillator for frequency modulating the carrier frequency signal of the oscillator with a data message for transmission of an optical signal within a given channel having a given carrier frequency by the LED after the power of the carrier frequency signal applied to the LED has been ramped up to the given value, wherein the data message is a digital signal; and a receiver tuned to the carrier frequency of the optical signal for receiving the optical signal from the transmitter. - View Dependent Claims (16, 17, 18)
-
Specification