US 11,858,000 B2
Ultrasonic device and ultrasonic sensor
Chikara Kojima, Matsumoto (JP); Koji Ohashi, Matsumoto (JP); Tomohiro Sayama, Matsumoto (JP); Seiji Izuo, Shiojiri (JP); and Kanechika Kiyose, Matsumoto (JP)
Assigned to SEIKO EPSON CORPORATION, Tokyo (JP)
Filed by SEIKO EPSON CORPORATION, Tokyo (JP)
Filed on Jan. 19, 2021, as Appl. No. 17/248,290.
Claims priority of application No. 2020-007660 (JP), filed on Jan. 21, 2020.
Prior Publication US 2021/0220874 A1, Jul. 22, 2021
Int. Cl. B06B 1/06 (2006.01)
CPC B06B 1/0622 (2013.01) 16 Claims
OG exemplary drawing
 
1. An ultrasonic device, comprising:
a substrate; and
a vibration plate provided on the substrate and having one or more vibrators configured to generate an ultrasonic wave by vibration, wherein
the vibration plate has a movable portion provided with the one or more vibrators and configured to vibrate accompanying with the vibration of the one or more vibrators, and a fixed portion fixed to the substrate,
the substrate is on a first side of the vibration plate,
the fixed portion has a space portion on a second side of the vibration plate opposite to the substrate, and
a volume of the space portion corresponding to the fixed portion of the vibration plate is set to or smaller than a predetermined volume such that a vibration frequency of a reflected wave based on a wave transmitted from the movable portion and received by the movable portion is outside a vibration frequency band region of the one or more vibrators.