DIRECTIONAL SPEAKER SYSTEM AND METHOD

• US 20180091916A1
• Filed: 03/24/2017
• Published: 03/29/2018
• Est. Priority Date: 09/26/2016
• Status: Active Application

• Current Assignee: STMicroelectronics Limited (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Limited (STMicroelectronics NV)
• Inventors: Alexandropoulos, Alexios
• Granted Patent: US 10,284,994 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 17/36 with phase comparison between the received signal and the contemporaneously transmitted signal
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/66 Tracking systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: H04R 2203/12 Beamforming aspects for stereophonic sound reproduction with loudspeaker arrays
• CPC Class Codes: H04R 2499/15 Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops
• CPC Class Codes: H04R 29/002 Loudspeaker arrays
• CPC Class Codes: H04R 29/008 Visual indication of individual signal levels visual indication of stereophonic sound image H04S7/40
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04S 3/002 Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution control circuits for electronic adaptation of the sound field H04S7/30
• CPC Class Codes: H04S 7/303 Tracking of listener position or orientation

Abstract

A directional loudspeaker system has a loudspeaker arrangement configured to generate N audio signals. A time-of-flight sensor arrangement is configured to detect a location of a user. A controller is configured to use information from the time-of-flight sensor arrangement about the location of the user to control the delay such that the N audio signals constructively interfere at the location of the user.

Claims

1. A directional loudspeaker system comprising:

a plurality of loudspeakers configured to generate N directional audio signals, wherein the N directional audio signals are such that at least one directional audio signal of the N directional audio signals has a delay with respect to at least one other directional audio signal, wherein N is an integer equal or greater than 2, wherein the N directional audio signals comprise sound waves having a common frequency in an audible spectrum, wherein the plurality of loudspeakers are configured to focus the N directional audio signals at a first location;

a time-of-flight sensor arrangement configured to determine information about the first location; and

a controller configured to use the information from the time-of-flight sensor arrangement about the first location to control the delay such that the N directional audio signals constructively interfere at the first location, wherein the constructive interference generates an audio signal having an amplitude greater than the N directional audio signals and the frequency.

2. The directional loudspeaker system according to claim 1, wherein the plurality of loudspeakers are spatially separated from each other.

3. The directional loudspeaker system according to claim 1, wherein the time-of-flight sensor arrangement comprises a plurality of time-of-flight sensors.

4. The directional loudspeaker system according to claim 3, wherein each of the time-of-flight sensors comprises a single photon avalanche diode (SPAD).

8. The directional loudspeaker system according to claim 1, wherein the controller is configured to use information from the time-of-flight sensor arrangement to track movement of a moving object and to correspondingly control the delay such that the N audio signals constructively interfere at the first location as the moving object moves.

9. The directional loudspeaker system according to claim 8, wherein a content of the audio signals is dependent on a position of the moving object.

10. The directional loudspeaker system according to claim 1, wherein N is such that each of the N directional audio signals is individually sub-audible.

11. The directional loudspeaker system according to claim 1, further comprising a display arrangement configured to display video content associated with the audio signals.

24. The directional loudspeaker system according to claim 1, wherein the N is equal to two, wherein one of the plurality of loudspeakers is spatially separated from another of the plurality of loudspeakers.

5-6. -6. (canceled)

7. The directional loudspeaker system according to claim wherein each of the time-of-flight sensors comprises a field-of-view, the directional loudspeaker system having an active area in which the N directional audio signals constructively interfere, wherein at least a part of each field-of-view of each time-of-flight sensor overlies the active area.

12. A directional loudspeaker method comprising:

determining information about a first location using a time-of-flight sensor arrangement; and

using the information from the time-of-flight sensor arrangement about the first location to control the delay of each of N directional audio signals, wherein N is an integer equal or greater than 2;

transmitting the N directional audio signals having a common frequency in an audible spectrum towards the first location, wherein the N directional audio signals are such that at least one audio directional signal of the N directional audio signals has the delay with respect to at least one other; and

at the first location, the delay causing the generation of an audio signal having an amplitude greater than the N directional audio signals and the common frequency.

13. The method according to claim 12, wherein transmitting the N directional audio signals comprises generating the N directional audio signals using a plurality of loudspeakers that are spatially separated.

14. The method according to claim 12, further comprising using information from the time-of-flight sensor arrangement to track movement of a moving object and to correspondingly control the delay such that the N directional audio signals constructively interfere at the first location of as the moving object moves.

15. The method according to claim 12, wherein N is such that each of the N directional audio signals is individually sub-audible.

16. The method according to claim 12, further comprising displaying video content associated with the N directional audio signals.

17. The method according to claim 12, wherein a content of the N directional audio signals is dependent on a position of a moving object.

23. The method according to claim 12, wherein the N is equal to two, wherein the transmitting N directional audio signals comprises transmitting from a first speaker location and a second speaker location that are spatially separated from each other.

18-22. -22. (canceled)

25. A directional loudspeaker system comprising:

a first directional loudspeaker configured to directionally transmit a first inaudible sound wave in an audible spectrum from a first location towards a second location;

a second directional loudspeaker configured to directionally transmit a second inaudible sound wave in the audible spectrum from a third location towards the second location;

a first time-of-flight sensor configured to determine a first distance between the first location and the second location;

a second time-of-flight sensor configured to determine a second distance between the third location and the second location, the first distance being different from the second distance; and

a controller configured to generate a phase difference between the first inaudible sound wave and the second inaudible sound wave that are being emitted so that the first inaudible sound wave and the second inaudible sound wave are configured to reach the first location with no phase difference.

26. The directional loudspeaker system according to in claim 25, wherein each of the first and the second time-of-flight sensors comprises a field-of-view, the directional loudspeaker system having an active area in which the first and the second inaudible sound waves constructively interfere, wherein at least a part of each field-of-view of each of the first and the second time-of-flight sensors overlies the active area.

27. The directional loudspeaker system according to claim 25, wherein the controller is configured to use information from the first and the second time-of-flight sensors to track movement of a moving object and to correspondingly control a phase difference between the first and the second inaudible sound waves such that the first and the second inaudible sound waves constructively interfere at the first location as the moving object moves.

28. The directional loudspeaker system according to claim 25, further comprising a display configured to display video content associated with the first and the second inaudible sound waves.

29. The directional loudspeaker system according to claim 25, wherein each of the first and the second time-of-flight sensors comprises a single photon avalanche diode (SPAD).

30. A method of transmitting audio, the method comprising:

determining a first distance between a first speaker position and a first hearing position using a first optical sensor at the first speaker position;

determining a second distance between the first speaker position and a second hearing position using the first optical sensor at the first speaker position;

determining a third distance between the second speaker position and the first hearing position using a second optical sensor at the second speaker position;

determining a fourth distance between the second speaker position and the second hearing position using the second optical sensor at the second speaker position;

directionally transmitting a first inaudible audio signal from a first speaker location to a first hearing position;

directionally transmitting a second inaudible audio signal from the first speaker location to a second hearing position;

directionally transmitting a third inaudible audio signal from a second speaker location to the first hearing position, wherein the first inaudible audio signal and the third inaudible audio signal have a first phase difference so as reach the first hearing position at the same time with no phase difference; and

directionally transmitting a fourth inaudible audio signal from the second speaker location to the second hearing position, wherein the second inaudible audio signal and the fourth inaudible audio signal have a second frequency, wherein the second inaudible audio signal and the fourth inaudible audio signal have a second phase difference so as to reach the second hearing position at the same time with no phase difference.

31. The method according to claim 30, wherein the first, the second, the third, and the fourth inaudible audio signals are simultaneously transmitted.