APPARATUS AND METHOD FOR EFFICIENT TWO-WAY OPTICAL COMMUNICATION WHERE TRANSMITTER MAY INTERFERE WITH RECEIVER

• US 20150063821A1
• Filed: 09/02/2014
• Published: 03/05/2015
• Est. Priority Date: 08/30/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Revolv Inc. (Alphabet Inc.)
• Inventors: MATHEWS, JEFFREY P., BRUNEAU, JONATHAN S., TAYLOR, LEE R.
• Granted Patent: US 9,413,463 B2
• Time in Patent Office: Days
• US Class Current: 398/139
• CPC Class Codes: H04B 10/1143 Bidirectional transmission
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04B 10/2507 for the reduction or elimination of distortion or dispersion
• CPC Class Codes: H04B 10/25891 Transmission components H04B10/40 takes precedence
• CPC Class Codes: H04B 10/40 Transceivers
• CPC Class Codes: H04B 10/502 LED transmitters

Abstract

An two-way optical communication apparatus, including a transmit element, a receive element, and a transceive processor. The transmit element is coupled to a light pipe, and transmits a first signal. The receive element is coupled to the light pipe, and receives a second signal. The transceive processor directs the transmit element to pause and then resume transmitting the first signal during first intervals, and directs the receive element to sample for the second signal during one or more second intervals within each of the first intervals, where the each of the first intervals is less than a first value and the first intervals occur at a duty cycle no greater than a second value, and where the first and second values are controlled by the transceive processor such that a user perceives the first optical signal as having a constant state for a third interval.

Claims

1. An apparatus for providing two-way optical communication, the apparatus comprising:

a transmit element, coupled to a light pipe, configured to transmit a first optical signal through said light pipe;

a receive element, also coupled to said light pipe, configured to receive a second optical signal through said light pipe; and

a transceive processor, coupled to said transmit and receive elements, configured to direct said transmit element to pause and then resume transmitting said first optical signal during first intervals, and configured to direct said receive element to sample for said second optical signal during one or more second intervals within each of said first intervals, wherein said each of said first intervals is less than a first value and said first intervals occur at a duty cycle no greater than a second value, and wherein said first and second values are controlled by said transceive processor such that a user perceives said first optical signal as having a constant state for a third interval.

2. The apparatus as recited in claim 1, wherein said first and second optical signals are at wavelengths in a range comprising the visible, ultraviolet, and infrared spectrums.

3. The apparatus as recited in claim 1, wherein said transmit element comprises a light emitting diode.

4. The apparatus as recited in claim 1, wherein said receive element comprises a phototransistor.

5. The apparatus as recited in claim 1, wherein said transmit and receive elements are disposed within a single transceive element that is coupled to one end of said light pipe.

6. The apparatus as recited in claim 1, wherein said transceive processor directs said transmit element to transmit a third optical signal during periods outside of said first intervals, and wherein said third optical signal is at a bit rate faster than can be perceived by said user, and wherein said bit rate is faster than that of said second optical signal.

7. The apparatus as recited in claim 1, wherein said transceive processor directs said transmit element to transmit a third optical signal during periods that include one or more of said first intervals, and wherein said third optical signal is at a bit rate faster than can be perceived by said user, but slower than that of said second optical signal, and wherein an encoding scheme for said third optical signal allows for fluctuations of said third optical signal for periods not greater than said first value without construing said third optical signal as having changed state.

8. An apparatus for providing two-way optical communication, the apparatus comprising:

a light pipe, configured to transport illumination from optical signals between ends of said light pipe

a transmit element, coupled to a first one or said ends, configured to transmit a first optical signal through said light pipe to a second one of said ends;

a receive element, coupled to said light pipe, configured to receive a second optical signal transported through said light pipe from said second one of said ends; and

a transceive processor, coupled to said transmit and receive elements, configured to direct said transmit element to pause and then resume transmitting said first optical signal during first intervals, and configured to direct said receive element to sample for said second optical signal during one or more second intervals within each of said first intervals, wherein said each of said first intervals is less than a first value and said first intervals occur at a duty cycle no greater than a second value, and wherein said first and second values are controlled by said transceive processor such that a user perceives said first optical signal as having a constant state for a third interval.

9. The apparatus as recited in claim 8, wherein said first and second optical signals are at wavelengths in a range comprising the visible, ultraviolet, and infrared spectrums.

10. The apparatus as recited in claim 8, wherein said transmit element comprises a light emitting diode.

11. The apparatus as recited in claim 8, wherein said receive element comprises a phototransistor.

12. The apparatus as recited in claim 8, wherein said transmit and receive elements are disposed within a single transceive element that is coupled to said first one of said ends of said light pipe.

13. The apparatus as recited in claim 8, wherein said transceive processor directs said transmit element to transmit a third optical signal during periods outside of said first intervals, and wherein said third optical signal is at a bit rate faster than can be perceived by said user, and wherein said bit rate is faster than that of said second optical signal.

14. The apparatus as recited in claim 8, wherein said transceive processor directs said transmit element to transmit a third optical signal during periods that include one or more of said first intervals, and wherein said third optical signal is at a bit rate faster than can be perceived by said user, but slower than that of said second optical signal, and wherein an encoding scheme for said third optical signal allows for fluctuations of said third optical signal for periods not greater than said first value without construing said third optical signal as having changed state.

15. A method for providing two-way optical communication in a shared light pipe, the method comprising:

via a transmit element, transmitting a first optical signal through the shared light pipe;

pausing and then resuming said transmitting during first intervals, wherein each of the first intervals is less than a first value and the first intervals occur at a duty cycle no greater than a second value, and wherein the first and second values are controlled by a transceive processor such that a user perceives the first optical signal as having a constant state for a third interval; and

via a receive element, receiving a second optical signal through the shared light pipe during one or more second intervals within each of the first intervals.

16. The method as recited in claim 15, wherein the first and second optical signals are at wavelengths in a range comprising the visible, ultraviolet, and infrared spectrums.

17. The method as recited in claim 15, wherein the transmit element comprises a light emitting diode.

18. The method as recited in claim 15, wherein the receive element comprises a phototransistor.

19. The method as recited in claim 15, wherein the transmit and receive elements are disposed within a single transceive element that is coupled to one end of the shared light pipe.

20. The method as recited in claim 15, further comprising:

transmitting a third optical signal during periods outside of the first intervals, and wherein the third optical signal is at a bit rate faster than can be perceived by the user, and wherein the bit rate is faster than that of the second optical signal.

21. The method as recited in claim 15, further comprising:

transmitting a third optical signal during periods that include one or more of the first intervals, and wherein the third optical signal is at a bit rate faster than can be perceived by the user, but slower than that of the second optical signal, and wherein an encoding scheme for the third optical signal allows for fluctuations of the third optical signal for periods not greater than the first value without construing the third optical signal as having changed state.