US 12,138,658 B2
Ultrasonic transducer
Fumiya Kurokawa, Nagaokakyo (JP); Yasuhiro Aida, Nagaokakyo (JP); Shinsuke Ikeuchi, Nagaokakyo (JP); Seiji Umezawa, Nagaokakyo (JP); and Masayuki Suzuki, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Aug. 24, 2022, as Appl. No. 17/894,217.
Application 17/894,217 is a continuation of application No. PCT/JP2020/044434, filed on Nov. 30, 2020.
Claims priority of application No. 2020-056416 (JP), filed on Mar. 26, 2020.
Prior Publication US 2022/0401994 A1, Dec. 22, 2022
Int. Cl. B06B 1/02 (2006.01); G10K 11/02 (2006.01)
CPC B06B 1/0292 (2013.01) [G10K 11/02 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An ultrasonic transducer comprising:
a first acoustic transducer including a first membrane section to perform flexural vibration;
a second acoustic transducer including a second membrane section facing the first membrane section and being spaced apart from the first membrane section, the second acoustic transducer being structured to vibrate in a thickness direction; and
a housing with a bottomed tubular shape, the housing including a bottom portion facing the first membrane section and being spaced apart from the first membrane section in the thickness direction, and a surrounding wall portion surrounding the first membrane section and the second membrane section and being spaced apart from each of the first membrane section and the second membrane section; wherein
the second acoustic transducer further includes an annular section supporting the second membrane section and being in contact with an entire or substantially an entire periphery of the second membrane section, and an acoustic matching plate facing the second membrane section and being spaced apart from the second membrane section, the acoustic matching plate being connected to the surrounding wall portion to define a sealed space with the housing;
an ultrasonic transmission path sandwiched between the first membrane section and the second membrane section is provided in the sealed space; and
a maximum inner width of the ultrasonic transmission path is smaller than a maximum inner width of the surrounding wall portion.