Systems and methods for acoustic beamforming using discrete or continuous speaker arrays

• US 8,000,170 B2
• Filed: 11/20/2008
• Issued: 08/16/2011
• Est. Priority Date: 11/20/2008
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Kablotsky, Joshua A.
• Primary Examiner(s): Pihulic; Dan
• Application Number:
  US12/274,771
• Publication Number:
  US 20100124150A1
• Time in Patent Office: 999 Days
• Field of Search: 367/138, 381/387, 381/423, 381/77, 381/79, 381/80, 381/82
• US Class Current: 367/138
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 2201/403 Linear arrays of transducers
• CPC Class Codes: H04R 2430/20 Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic H04R2203/12 takes precedence

Abstract

In various embodiments, the invention pertains to systems for acoustic beamforming that include one or more speaker membranes, such as, for example, a continuous ribbon membrane, and several independently addressable drivers. Moreover, certain embodiments relate to methods for beamforming with improved directionality.

Claims

1. A system for acoustic beamforming, comprising:

(a) an elongated, continuous electro-acoustic transducer membrane having a length; and

(b) a plurality of spaced-apart drivers disposed along the length of the transducer, the drivers each independently driving an adjacent region of the transducer according to a time-varying signal applied thereto with an associated time delay.

2. The system of claim 1 wherein the electro-acoustic transducer membrane is substantially ribbon-shaped.

3. The system of claim 1 wherein the drivers are electromagnetic drivers.

4. The system of claim 1 wherein the drivers are piezoelectric drivers.

5. The system of claim 1 wherein the electro-acoustic transducer membrane is suspended in a magnetic field and comprises electrically conductive sections.

6. The system of claim 1 further comprising at least one electrical amplifier for supplying the time-varying signal to the drivers via output channels each associated with a time delay.

7. The system of claim 1 further comprising at least a second elongated, continuous electro-acoustic transducer membrane having a length and a second plurality of spaced-apart drivers disposed along the length of the second transducer, the second membrane and second drivers cooperating with the other membrane and the other drivers so as to enhance the beamforming performance thereof.

8. A method for acoustic beamforming with improved directionality, the method comprising:

(a) receiving a multi-frequency signal representing sound;

(b) separating out low-frequency components from the signal, and generating higher harmonics of the low-frequency components;

(c) combining the multi-frequency signal with the higher harmonics to form an edited multi-frequency signal; and

(d) supplying the edited multi-frequency signal to a plurality of speaker drivers with various time delays.

9. The method of claim 8 wherein the edited multi-frequency signal comprises the low-frequency components.

10. The method of claim 8 wherein the edited multi-frequency signal lacks the low-frequency components.

11. The method of claim 8 wherein the acoustic beamforming results in stereophonic sound.

12. A method of acoustic beamforming, the method comprising the steps of:

(a) providing an elongated, continuous electro-acoustic transducer membrane having a length; and

(b) driving the transducer at a plurality of spaced-apart regions along the length according to a time-varying signal and time delays associated with the regions.

13. The method of claim 12 wherein the electro-acoustic transducer membrane is substantially ribbon-shaped.

14. The method of claim 12 wherein the drivers are electromagnetic drivers.

15. The method of claim 12 wherein the drivers are piezoelectric drivers.

16. The method of claim 12 wherein the electro-acoustic transducer membrane is suspended in a magnetic field and comprises electrically conductive sections.

17. The method of claim 12 further comprising:

(c) providing a second elongated, continuous electro-acoustic transducer membrane having a second length; and

(d) driving the second transducer membrane at a plurality of spaced-apart regions along the second length according to the time-varying signal and time delays associated with the regions.