ULTRASONIC TRANSDUCER FOR A PROXIMITY SENSOR

• US 20090189488A1
• Filed: 01/29/2008
• Published: 07/30/2009
• Est. Priority Date: 01/29/2008
• Status: Active Grant

• Current Assignee: Tmss France
• Original Assignee: Hyde Park Electronics, LLC
• Inventors: Ray, Rand Kalani, Shah, Piyush J.
• Granted Patent: US 7,804,742 B2
• Time in Patent Office: Days
• US Class Current: 310/334
• CPC Class Codes: G01S 7/521 Constructional features
• CPC Class Codes: G10K 9/122 using piezoelectric driving means G10K9/121 takes precedence
• CPC Class Codes: H03H 9/176 consisting of ceramic material H03H9/177, H03H9/178 take precedence

Abstract

An ultrasonic transducer assembly for use in sensing the location of objects in proximity to the transducer. The ultrasonic transducer assembly includes a substrate member, a piezoceramic resonator plate supported on a planar surface of the substrate member adjacent to a peripheral edge of the substrate member, and a coupler connected to a surface of the resonator plate for acoustically coupling the resonator plate to a medium in contact with the coupler.

Claims

1. An ultrasonic transducer assembly for use in sensing the location of objects in proximity to the transducer, said ultrasonic transducer assembly comprising:

a substrate member comprising a planar surface and a peripheral edge;

a piezoceramic resonator plate supported adjacent to said planar surface; and

a coupler connected to a surface of said resonator plate for acoustically coupling said resonator plate to a medium in contact with said coupler.

2. The ultrasonic transducer assembly of claim 1, wherein said resonator plate comprises a rectangular plate defining an elongated major dimension and a minor dimension and said coupler is attached adjacent an end of said major dimension.

3. The ultrasonic transducer assembly of claim 1, wherein said coupler comprises a substantially rigid plate-like diaphragm member extending transverse to said resonator plate.

4. The ultrasonic transducer assembly of claim 3, wherein said coupler further comprises an impedance matching member extending over said plate-like member.

5. The ultrasonic transducer assembly of claim 4, wherein said diaphragm member includes an aperture and said resonator plate extends to said aperture, and including a bonding structure mechanically connecting said surface of said resonator plate to said diaphragm member and to said impedance matching member.

6. The ultrasonic transducer assembly of claim 5, wherein said diaphragm member comprises a disk-shaped member.

7. The ultrasonic transducer assembly of claim 5, including a damping material located on a side of said coupler opposite said medium, and including a resilient isolation layer separating said diaphragm member from said damping material.

8. The ultrasonic transducer assembly of claim 1, wherein said substrate member comprises a printed circuit board, and said resonator plate is electrically connected to said printed circuit board through a surface mount technology contact formed between said planar surface of said substrate member and a planar inner side surface of said resonator plate.

9. The ultrasonic transducer assembly of claim 8, including an electrical conductor extending between an outer side of said resonator plate, opposite said inner side, and said printed circuit board.

10. The ultrasonic transducer assembly of claim 9, wherein said coupler comprises a generally planar member extending transverse to said resonator plate.

11. The ultrasonic transducer assembly of claim 1, wherein said resonator plate is supported in cantilever relation on a contact pad extending in spaced relation generally parallel to said substrate member.

12. The ultrasonic transducer assembly of claim 11, wherein said substrate member includes a peninsula portion extending in cantilever relation from said peripheral edge of said substrate member and defines a portion of said planar surface.

13. The ultrasonic transducer assembly of claim 11, wherein said resonator plate comprises a disk-shaped member and is soldered to said contact pad at a geometric center portion of said resonator plate.

14. The ultrasonic transducer assembly of claim 1, wherein said coupler is bonded to a planar surface of said resonator plate such that a path for acoustic signals transmitted from and received by said resonator plate extends in a direction that is orthogonal to said planar surface of said substrate member.

15. An ultrasonic transducer assembly for use in sensing the location of objects in proximity to the transducer, said ultrasonic transducer assembly comprising:

a substrate member comprising a printed circuit board defining a planar surface and a peripheral edge;

a piezoceramic resonator plate including a planar inner surface supported at said planar surface adjacent to said peripheral edge;

electrical contacts between said printed circuit board and said resonator plate for connecting said resonator plate to a power supply; and

a coupler comprising a planar member including opposing first and second sides, said first side extending transverse to and connected to a surface of said resonator plate for acoustically coupling said resonator plate to a medium in contact with said second side of said coupler.

16. The ultrasonic transducer assembly of claim 15, wherein said resonator plate comprises a rectangular plate defining an elongated major dimension and a minor dimension, and said resonator plate is supported in cantilever relation on a contact pad with its elongated major dimension extending from said peripheral edge of said substrate member.

17. The ultrasonic transducer assembly of claim 15, wherein said coupler comprises a substantially rigid disk-shaped diaphragm and an impedance matching member of a different material than said diaphragm extending over said diaphragm and defining said second side, and said coupler further includes a bonding structure mechanically connecting said surface of said resonator plate to said diaphragm and said impedance matching member at said first side.

18. The ultrasonic transducer assembly of claim 17, including a damping material surrounding said substrate member, said resonator plate and said coupler, and said coupler further comprises a resilient isolation layer separating said diaphragm from said damping material.

19. A sensor including an ultrasonic transducer assembly for use in sensing the location of objects in proximity to the transducer, said sensor comprising:

a substrate member comprising a printed circuit board defining a planar surface and a peripheral edge;

a rectangular piezoceramic resonator plate defining an elongated major dimension and a minor dimension, said resonator plate being supported in cantilever relation on said substrate member with its elongated major dimension extending from said peripheral edge of said substrate member;

electrical contacts between said printed circuit board and said resonator plate for connecting said resonator plate to a power supply, one of said electrical contacts forming a cantilever support for said resonator plate on said substrate member; and

a disk-shaped coupler comprising a planar member including opposing first and second sides, said first side extending transverse to and connected to a surface of said resonator plate, said coupler being acoustically excited by said resonator plate to transmit a signal to an object in proximity to said coupler, and said coupler receiving and transmitting reflected signals from said object to said resonator plate.

20. The sensor of claim 19, wherein said coupler comprises a substantially rigid diaphragm and an impedance matching member of a different material than said diaphragm extending over said diaphragm and defining said second side, and said coupler further includes a bonding structure mechanically connecting said surface of said resonator plate to said diaphragm and said impedance matching member at said first side.

21. The sensor of claim 20, including a housing containing a damping material surrounding said substrate member, said resonator plate and said coupler, and said coupler further comprises a resilient isolation layer separating said diaphragm from said damping material.