Panel loudspeaker controller and a panel loudspeaker

• US 10,362,395 B2
• Filed: 02/23/2018
• Issued: 07/23/2019
• Est. Priority Date: 02/24/2017
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: NVF Tech Ltd. (Alphabet Inc.)
• Inventors: Harris, Neil John
• Primary Examiner(s): Gauthier, Gerald
• Application Number:
  US15/904,077
• Publication Number:
  US 20180249248A1
• Time in Patent Office: 515 Days
• Field of Search: 381 59, 381152, 381190, 381332, 381333, 381354, 381399, 381412, 381431, 381 17, 381 18, 381 66, 381 712, 381 717, 381 77, 381 86, 381 98, 381 99, 381162, 381182, 381396, 381401, 381432, 493 52, 715766, 73597, 84721, 181163, 181167, 318561, 34053914, 4555501, 711106
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: H04R 2440/01 Acoustic transducers using travelling bending waves to generate or detect sound
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 2499/15 Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops
• CPC Class Codes: H04R 29/001 for loudspeakers H04R29/007 takes precedence
• CPC Class Codes: H04R 29/002 Loudspeaker arrays
• CPC Class Codes: H04R 3/04 for correcting frequency response
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 7/045 using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion

Abstract

A panel loudspeaker controller for controlling a panel loudspeaker including a plurality of actuators, the panel loudspeaker controller including a plurality of electrical signal inputs, each input being associated with each actuator of the panel loudspeaker to be controlled; a plurality of signal processors, each signal processor being associated with each input and having an output for an electrical signal to control an actuator of the panel loudspeaker, and each signal processor implementing a transfer function from its input to its output based on each actuator of the panel loudspeaker to a desired acoustic receiver; and a signal processor controller associated with all of the plurality of signal processors, wherein the signal processor controller is preconfigured to improve phase alignment between the signals as an ensemble output at the outputs of the signal processors.

Claims

1. A panel loudspeaker controller for controlling a panel loudspeaker comprising a plurality of actuators attached to a panel, the panel loudspeaker controller comprising:

a plurality of electrical signal inputs, each input being associated with each actuator of the panel loudspeaker to be controlled;

a plurality of signal processors, each signal processor being associated with each input and having an output for an electrical signal to control an actuator of the panel loudspeaker, and each signal processor implementing a transfer function from its input to its output based on each actuator of the panel loudspeaker to a desired acoustic receiver; and

a signal processor controller associated with all of the plurality of signal processors, wherein the signal processor controller is preconfigured to improve phase alignment between the signals as an ensemble output at the outputs of the signal processors to reduce cancellation of a contribution to an acoustic output of the panel of one actuator by another.

2. The panel loudspeaker controller of claim 1, wherein the signal processor controller comprises a filter in order to be preconfigured to improve phase alignment between the signals as an ensemble output at the outputs of the signal processors.

3. The panel loudspeaker controller of claim 2, wherein the filter comprises a low pass filter and/or an all-pass filter.

4. The panel loudspeaker controller of claim 3, wherein the low pass filter passes signals with a frequency lower than a cut-off frequency of 500 Hz.

5. The panel loudspeaker controller of claim 1, wherein each signal processor comprises a digital signal processor.

6. The panel loudspeaker controller of claim 1, wherein the signal processor controller comprises a digital signal processor in order to be preconfigured to improve phase alignment between the signals as an ensemble output at the outputs of the signal processors.

7. The panel loudspeaker controller of claim 1, wherein signal processing is applied by the signal processor controller to the electrical signal inputs to achieve a maximum or near maximum total ensemble output at the outputs at all frequencies.

8. The panel loudspeaker controller of claim 1, wherein signal processing is applied by the signal processor controller to the electrical signal inputs to achieve a minimum or near minimum acoustic pressure at one or more predetermined spatial locations.

9. The panel loudspeaker controller of claim 1, wherein the signal processor controller comprises an equaliser in order to be preconfigured to improve phase alignment between the signals as an ensemble output at the outputs of the signal processors wherein the equaliser equalises the input signals.

10. The panel loudspeaker controller of claim 1, wherein the plurality of actuators comprise at least one piezoelectric actuator, such as a piezoelectric patch and/or at least one coil and magnet-type actuator and/or a distributed mode actuator.

11. The panel loudspeaker controller of claim 1, wherein the plurality of actuators comprise an array of actuators.

12. The panel loudspeaker controller of claim 1, wherein the acoustic receiver comprises an ear of a user or a microphone.

13. An electronic device configured to configure a signal processor controller of a panel loudspeaker comprising a plurality of actuators, the electronic device being configured to:

input electrical signals into a plurality of electrical signal inputs, each input being associated with each actuator of the panel loudspeaker to be controlled;

measure a response of the panel loudspeaker to the electrical inputs as an ensemble; and

use the response to configure a signal processor controller, associated with all of a plurality of signal processors, to improve phase alignment, in use, between signals output at the outputs of the plurality of signal processors as an ensemble, wherein each signal processor is associated with each input and has an output for an electrical signal to control an actuator of the panel loudspeaker, and each signal processor implements a transfer function from its input to its output based on each actuator of the panel loudspeaker to a desired acoustic receiver.

14. The electronic device of claim 13, wherein the input electrical signals, actuators, panel loudspeaker and response are implemented virtually.

15. The electronic device of claim 13, wherein the input electrical signals take the form of an impulse and the response takes the form of an impulse response.

16. The electronic device of claim 13, wherein the electronic device is configured to use the response to configure the signal processor controller by assessing differences between transfer functions of the signal processors.

17. A method of configuring a signal processor controller of a panel loudspeaker comprising a plurality of actuators, the method comprising:

inputting electrical signals into a plurality of electrical signal inputs, each input being associated with each actuator of the panel loudspeaker to be controlled;

measuring a response of the panel loudspeaker to the electrical inputs as an ensemble; and

using the response to configure a signal processor controller, associated with all of a plurality of signal processors, to improve phase alignment, in use, between signals output at the outputs of the plurality of signal processors as an ensemble, wherein each signal processor is associated with each input and has an output for an electrical signal to control an actuator of the panel loudspeaker, and each signal processor implements a transfer function from its input to its output based on each actuator of the panel loudspeaker to a desired acoustic receiver.

18. The method of claim 17, wherein the input electrical signals take the form of an impulse and the response takes the form of an impulse response.

19. The method of claim 17, wherein using the response to configure the signal processor controller comprises assessing differences between transfer functions of the signal processors.