Digital MEMS loudspeaker

Patent metadata

Field	Value
Publication number	US-9686610-B2
Application number	US-201514843469-A
Country	US
Kind code	B2
Filing date	Sep 2, 2015
Priority date	Sep 2, 2015
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

Devices related to digital MEMS loudspeakers are discussed. Such devices may include an air pressure source, MEMS valves coupled to the air pressure source, and an audio modulator coupled to the MEMS valve to receive an audio signal and to control the MEMS valves via a modulation signal to provide an acoustic output.

First claim

What is claimed is:

1. A digital loudspeaker comprising:
an air pump coupled between a high-pressure chamber and a low-pressure chamber;
a plurality of first valves, individual ones of the first valves having an inlet in fluid communication with the high-pressure chamber and an outlet in fluid communication with a front cavity;
a plurality of second valves, individual ones of the second valves having an inlet in fluid communication with the front cavity an outlet in fluid communication with the low-pressure chamber; and
an audio modulator coupled to the first and second valves, the audio modulator to receive an audio signal and to control the valves via a modulation signal to provide an acoustic output from the front cavity.

2. The digital loudspeaker of claim 1 , wherein individual ones of the first and second valves comprise a MEMS valve.

3. The digital loudspeaker of claim 1 , wherein the air pressure pump comprises at least one of a piezoelectric MEMS pump, an electrostatic MEMS pump, or a magnetic MEMS pump.

4. The digital loudspeaker of claim 1 wherein the front cavity is exposed to ambient atmosphere, the low pressure chamber is below ambient atmospheric pressure, and the high pressure chamber is above ambient atmospheric pressure.

5. The digital loudspeaker of claim 1 , wherein the modulation signal comprises at least one of a pulse width modulation signal, a pulse density modulation signal, pulse amplitude modulation signal, or a pulse frequency modulation signal.

6. The digital loudspeaker of claim 1 , wherein the audio modulator is to generate a separate modulation signal for individual ones of the first or second valves.

7. The digital loudspeaker of claim 1 , wherein the modulation signal is to control all of the first valves.

8. The digital loudspeaker of claim 1 , wherein the modulation signal is to control all of the plurality of first valves and the audio modulator is to generate a second modulation signal to control all of the plurality of second valves.

9. The digital loudspeaker of claim 1 , wherein the plurality of first or second valves comprises a plurality of MEMS valves including a first MEMS valve having first characteristics and a second MEMS valve having at least one characteristic different than the first characteristics.

10. The system of claim 9 , wherein the front cavity comprises a Hemholtz resonator.

11. The digital loudspeaker of claim 1 , wherein the audio modulator is to directly digitally generate the modulation signal based on the audio signal.

12. The digital loudspeaker of claim 1 , wherein the front cavity comprises a Hemholtz resonator.

13. The digital loudspeaker of claim 1 , wherein:
the first and second plurality of valves are arrayed over a surface of the front cavity;
the first plurality of valves are arrayed over a surface of the high-pressure chamber; and
the second plurality of valves are arrayed over a surface of the low-pressure chamber.

14. A system comprising:
a memory configured to store audio data;
an air pump coupled between a high-pressure chamber and a low-pressure chamber;
a plurality of first valves, individual ones of the first valves having an inlet in fluid communication with the high pressure chamber and an outlet in fluid communication with a front cavity;
a plurality of second valves, individual ones of the second valves having an inlet in fluid communication with the front cavity an outlet in fluid communication with the low-pressure chamber; and
a processor coupled to the first and second valves and the memory, the processor to generate a modulation signal based on the audio data and to control the first and second valves based on the modulation signal to provide an acoustic output from the front cavity.

15. The system of claim 14 , wherein the plurality of first and second valves comprise a plurality of MEMS valves.

16. The system of claim 14 , wherein the processor is to generate a separate modulation signal for individual ones of the first or second valves.

17. The system of claim 14 , wherein the processor and the first and second valves are disposed on a single die to form a monolithic device.

18. The system of claim 17 , further comprising a wireless radio coupled to the processor; and wherein the monolithic device is housed within a wireless ear bud.

19. At least one non-transitory machine readable medium having a plurality of instructions stored thereon that, in response to being executed by a device, cause the device to provide an acoustic output by:
receiving an audio signal;
generating a modulation signal based on the received audio signal; and
controlling a plurality of first valves and a plurality of second valves coupled to an air pump based on the modulation signal to provide an acoustic output, wherein individual ones of the first valves have an inlet in fluid communication with a high-pressure side of the pump and an outlet in fluid communication with a front cavity, and individual ones of the second valves have an inlet in fluid communication with the front cavity an outlet in fluid communication with a low-pressure side of the pump.

20. The machine readable medium of claim 19 , wherein the modulation signal comprises at least one of a pulse width modulation signal, a pulse density modulation signal, pulse amplitude modulation signal, or a pulse frequency modulation signal.

21. The machine readable medium of claim 19 , wherein the modulation signal comprises a separate modulation signal for individual ones of the first or second valves.

22. The machine readable medium of claim 19 , wherein the first and second valves comprise a plurality of MEMS valves, the modulation signal is to control all of the first valves and the machine readable medium comprises further instructions that, in response to being executed by the device, cause the device to provide the acoustic output by generating a second modulation signal to control all of the second valves.

23. The medium of claim 19 , wherein the front cavity comprises a Hemholtz resonator.

Assignees

• Intel Corp

Inventors

• Kursula Mikko
• Makinen Kalle I
• Lahti Saku

Classifications

• H04R1/20

  Arrangements for obtaining desired frequency or directional characteristics (for stereophonic purpose H04R5/00) · CPC title

• H04R3/12 Primary

  for distributing signals to two or more loudspeakers {(specially adapted for hearing aids H04R25/407)} · CPC title

• H04R1/2811

  for loudspeaker transducers · CPC title

• H04R17/00

  Piezoelectric transducers; Electrostrictive transducers (piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners {H10N30/00}) · CPC title

• H04R1/403

  loud-speakers · CPC title