Parametric ring emitter

• US 6,359,990 B1
• Filed: 08/18/1998
• Issued: 03/19/2002
• Est. Priority Date: 04/30/1997
• Status: Expired due to Fees

• Current Assignee: American Technology Incorporated (Emerson Electric Company)
• Original Assignee: American Technology Incorporated (Emerson Electric Company)
• Inventors: Norris, Elwood G.
• Primary Examiner(s): Harvey, Minsun Oh
• Application Number:
  US09/135,732
• Time in Patent Office: 1,309 Days
• Field of Search: 381/75, 381/77, 381/82, 381/373, 181/171, 181/179, 181/180
• US Class Current: 381/77
• CPC Class Codes: F41H 13/0081 the high-energy beam being acoustic, e.g. sonic, infrasonic or ultrasonic
• CPC Class Codes: G10K 15/02 Synthesis of acoustic waves synthesis of speech G10L13/00
• CPC Class Codes: H04R 2217/03 Parametric transducers where sound is generated or captured by the acoustic demodulation of amplitude modulated ultrasonic waves
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• CPC Class Codes: H04R 27/04 Electric megaphones

Abstract

A sound emiting device for providing at least one new sonic or subsonic frequency as a by-product of emitting a waveform of at least two ultrasonic frequencies whose difference in value corresponds to the desired new sonic or subsonic frequency. The device includes a parametric emitting perimeter positioned around a central open section. This open section is structured with a diagonal width greater than a cross-sectional diagonal of the parametric emitting perimeter. An ultrasonic frequency signal source and sonic/subsonic frequency generator are coupled together to a modulating circuit for mixing an ultrasonic frequency signal with an electrical signal corresponding to the at least one new sonic or subsonic frequency. The modulator output is coupled to the emitting perimeter which comprises ultrasonic frequency emitting material for propagating the mixed waveform into air for demodulating the waveform to generate the at least one new sonic or subsonic frequency.

Claims

1. A sound emitting device for providing at least one new sonic frequency as a by-product of emitting at least two ultrasonic frequencies from an ultrasonic frequency emitter, said device comprised of:

an audio emitting perimeter positioned around a central open section, said open section having a diagonal width greater than a cross-sectional diagonal of the emitting perimeter of the support base, said audio emitting perimeter, said audio emitting perimeter having a directional orientation along a transmission axis;

an ultrasonic frequency signal source for generating a first ultrasonic signal;

a sonic or subsonic frequency generator for supplying an electrical signal corresponding to the at least one new sonic or subsonic frequency;

modulating means coupled to the ultrasonic frequency signal source and sonic or subsonic frequency generator for mixing the first ultrasonic frequency signal with the electrical signal corresponding to the at least one new sonic frequency to thereby generate a waveform including the first ultrasonic frequency signal and a second ultrasonic frequency signal;

said emitting perimeter comprising ultrasonic frequency emitting material coupled to an output of the modulating means for (i) propagating a waveform embodying both the first and second ultrasonic frequency signals, and (ii) generating the at least one new sonic frequency as a by-product of interaction between the first and second ultrasonic frequency signals.

2. A device as defined in claim 1, wherein the audio emitting perimeter comprises a circular array of ultrasonic emitters.

3. A device as defined in claim 1, wherein the ultrasonic emitters comprise a circular array of bimorf transducers.

4. A device as defined in claim 1, wherein the audio emitting perimeter comprises a circular configuration of ultrasonic emitter film.

5. A device as defined in claim 4, wherein the circular array is configured in multiple segments which collectively define at least portions of said audio emitting perimeter.

6. A device as defined in claim 4, wherein the circular configuration includes multiple segments which form arcuate sectors of the audio emitting perimeter.

7. A device as defined in claim 1, wherein the emitting perimeter is configured with a circular geometry.

8. A device as defined in claim 5, wherein the emitting perimeter comprises a substantially continuous circular array of arcuate sectors in end-to-end relationship.

9. A device as defined in claim 1, wherein the audio emitting perimeter comprises a rectangular configuration of ultrasonic emitters.

10. A device as defined in claim 1, wherein the audio emitting perimeter comprises a rectangular array of bimorf transducers.

11. A device as defined in claim 1, wherein the audio emitting perimeter comprises a rectangular configuration of ultrasonic film emitter members.

12. A device as defined in claim 11, wherein the rectangular configuration is in multiple segments which collectively define said audio emitting perimeter.

13. A device as defined in claim 11, wherein the rectangular configuration comprises multiple segments which are configured as linear sectors which collectively define larger straight line sections of the audio emitting perimeter.

14. A device as defined in claim 11, wherein the emitting perimeter is configured with a rectangular geometry.

15. A device as defined in claim 11, wherein emitting perimeter comprises a substantially continuous rectangular array of straight line sectors in end-to-end relationship.

16. A device as defined in claim 1, wherein the audio emitting perimeter comprises a polygon configuration of ultrasonic emitters.

17. A device as defined in claim 16, wherein the audio emitting perimeter comprises a polygon array of bimorf transducers.

18. A device as defined in claim 16, wherein the audio emitting perimeter comprises a polygon array of ultrasonic film emitter members.

19. A device as defined in claim 18, wherein the polygon array is configured in multiple segments which collectively define said audio emitting perimeter.

20. A device as defined in claim 18, wherein the polygon array is configured in multiple segments which are configured as linear sectors which collectively define larger straight line sections of the audio emitting perimeter.

21. A device as defined in claim 18, wherein the emitting perimeter is configured with a polygon geometry.

22. A device as defined in claim 18, wherein emitting perimeter comprises a substantially continuous polygon array of straight line sectors in end to end relationship.

23. A device as defined in claim 1, wherein a ratio of (i) a difference between an inner radius and an outer radius of the emitting perimeter, to (ii) the outer radius of the emitting perimeter is within a numerical range of 0.1 to 1.0.

24. A device as defined in claim 23, wherein the ratio is within the numerical range of 0.2 to 0.4.

25. A device as defined in claim 1, wherein the ultrasonic frequency emitting materials comprise a single ring surrounding a region without ultrasonic emitting material.

26. A device as defined in claim 1, comprising a plurality of rings of ultrasonic frequency emitting material concentrically oriented.

27. A device as defined in claim 11, wherein the emitting material comprises piezoelectric film material positioned in tension to provide an emitting diaphragm.

28. A device as defined in claim 11, wherein the emitting material comprises a dielectric film having a conductive layer for providing an electrostatic emitter membrane.