# US 12,120,483 B2 · Audio device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,483 B2 - Document ID: US12120483B2 - Status: Granted - Kind: B2 - Application number: 17/424,257 - Filed: 2020-01-20 - Published: 2022-03-03 - Granted: 2024-10-15 - Earliest claimed: 2019-01-21 - Assignees: TDK Corporation - Applicants: TDK Corporation - Inventors: Yoshiki Ohta; Takuto Horii; Yoshikazu Shimura; Atsushi Ezawa; Miho Bamba; Kaoru Kijima; Akihiro Takeda - Web page: https://patentgrep.com/patent/US12120483B2 ## CPC - H04R 1/24: Structural combinations of separate transducers or of two parts of the same transducer and responsive respectively to two or more frequency ranges - H04R 7/04: Plane diaphragms - H04R 17/00: Piezoelectric transducers; Electrostrictive transducers (piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners {H10N30/00}) - H10N 30/2047: {Membrane type} - H10N 30/50: having a stacked or multilayer structure - H10N 30/874: {embedded within piezoelectric or electrostrictive material, e.g. via connections} - H10N 30/875: {Further connection or lead arrangements, e.g. flexible wiring boards, terminal pins} - H04R 2499/11: Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's - H10N 30/503: {having a non-rectangular cross-section in a plane orthogonal to the stacking direction, e.g. polygonal or circular in top view} - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract An audio device includes a vibration member, and a first piezoelectric vibrator and a second piezoelectric vibrator that are provided on the vibration member. A natural frequency of the first piezoelectric vibrator is larger than a natural frequency of the second piezoelectric vibrator. ## Claims ### Claim 1 An audio device comprising: a vibration member; and a first piezoelectric vibrator and a second piezoelectric vibrator on the vibration member, wherein a natural frequency of the first piezoelectric vibrator is larger than a natural frequency of the second piezoelectric vibrator, the first piezoelectric vibrator is one of a pair of first piezoelectric vibrators, the pair of first piezoelectric vibrators is on both sides of a straight line which passes through a gravity center of a main face of the vibration member when viewed from a direction orthogonal to the main face of the vibration member, a distance between the first piezoelectric vibrator and the gravity center is shorter than a distance between the second piezoelectric vibrator and the gravity center, the pair of first piezoelectric vibrators is spaced apart from the gravity center, and the second piezoelectric vibrator is spaced apart from the gravity center. ### Claim 2 (depends on 1) The audio device according to claim 1, wherein a maximum length of the first piezoelectric vibrator is shorter than a maximum length of the second piezoelectric vibrator when viewed from a direction orthogonal to a main face of the vibration member. ### Claim 3 (depends on 1) The audio device according to claim 1, wherein the first piezoelectric vibrator and the second piezoelectric vibrator are synchronously driven by a same drive signal. ### Claim 4 (depends on 1) The audio device according to claim 1, wherein a distance between the first piezoelectric vibrator and the second piezoelectric vibrator is longer than a maximum length of the second piezoelectric vibrator when viewed from a direction orthogonal to a main face of the vibration member. ### Claim 5 (depends on 1) The audio device according to claim 1, wherein a distance between the first piezoelectric vibrator and the second piezoelectric vibrator is shorter than a maximum length of the second piezoelectric vibrator when viewed from a direction orthogonal to a main face of the vibration member. ### Claim 6 (depends on 1) The audio device according to claim 1, further comprising a restraint member restraining the vibration member, wherein a distance between the first piezoelectric vibrator and the restraint member is longer than a distance between the second piezoelectric vibrator and the restraint member when viewed from a direction orthogonal to a main face of the vibration member. ### Claim 7 (depends on 6) The audio device according to claim 6, wherein a distance between the first piezoelectric vibrator and a gravity center of a main face of the vibration member is shorter than a distance between the second piezoelectric vibrator and the gravity center when viewed from a direction orthogonal to the main face. ### Claim 8 (depends on 1) The audio device according to claim 1, further comprising a third piezoelectric vibrator on the vibration member, wherein a natural frequency of the third piezoelectric vibrator is smaller than the natural frequency of the first piezoelectric vibrator and larger than the natural frequency of the second piezoelectric vibrator. ### Claim 9 (depends on 1) The audio device according to claim 1, wherein the pair of first piezoelectric vibrators is line-symmetric with respect to the straight line when viewed from the direction orthogonal to a main face of the vibration member. ### Claim 10 (depends on 9) The audio device according to claim 9, wherein the second piezoelectric vibrator is one of a pair of second piezoelectric vibrators, the pair of second piezoelectric vibrators is line-symmetric with respect to the straight line when viewed from the direction. ### Claim 11 (depends on 1) The audio device according to claim 1, wherein the first piezoelectric vibrator includes a plurality of piezoelectric layers laminated in a direction orthogonal to a main face of the vibration member. ### Claim 12 (depends on 1) The audio device according to claim 1, wherein the first piezoelectric vibrator includes an element body and an external electrode, the element body includes a first face and a second face opposing each other, the first face is connected to the vibration member, and the external electrode is on the second face. ### Claim 13 (depends on 12) The audio device according to claim 12, wherein the first piezoelectric vibrator further includes an internal electrode and a via conductor, and the external electrode is electrically connected to the internal electrode through the via conductor. ### Claim 14 (depends on 12) The audio device according to claim 12, further comprising a wiring member connected to the external electrode, and the wiring member is a flexible printed circuit board or a flexible flat cable. ### Claim 15 (depends on 1) The audio device according to claim 1, wherein the first piezoelectric vibrator has a rectangular shape having a pair of long sides and a pair of short sides when viewed from a direction orthogonal to a main face of the vibration member. ### Claim 16 (depends on 1) The audio device according to claim 1, wherein the first piezoelectric vibrator has a square shape when viewed from the direction orthogonal to the main face of the vibration member. ### Claim 17 (depends on 1) The audio device according to claim 1, wherein the first piezoelectric vibrator has an elliptical shape when viewed from the direction orthogonal to the main face of the vibration member. ### Claim 18 (depends on 1) The audio device according to claim 1, wherein the first piezoelectric vibrator has a circular shape when viewed from the direction orthogonal to the main face of the vibration member. ### Claim 19 An audio device comprising: a vibration member; and a first piezoelectric vibrator and a second piezoelectric vibrator on the vibration member, wherein a natural frequency of the first piezoelectric vibrator is larger than a natural frequency of the second piezoelectric vibrator, the first piezoelectric vibrator and second piezoelectric vibrator are on a main face of the vibration member, on the same side of a line passing through a gravity center of the main face, and spaced apart from each other.