# US 8,569,930 B2 · Piezoelectric actuator and audio components > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,930 B2 - Document ID: US8569930B2 - Status: Granted - Kind: B2 - Application number: 13/319,872 - Filed: 2010-04-12 - Published: 2012-05-17 - Granted: 2013-10-29 - Earliest claimed: 2009-05-11 - Assignees: NEC Corporation - Applicants: Masatake Takahashi; Yasuhiro Sasaki; Yasuharu Onishi; Yukio Murata; Ukyo Mori; Jun Kuroda - Inventors: Masatake Takahashi; Yasuhiro Sasaki; Yasuharu Onishi; Yukio Murata; Ukyo Mori; Jun Kuroda - Web page: https://patentgrep.com/patent/US8569930B2 ## CPC - 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}) - H04R 7/06: comprising a plurality of sections or layers - H10N 30/2047: {Membrane type} - 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 One object of the present invention is to an achieve increase of amplitude of vibrations and/or flattening of frequency dependence of the amplitude of a piezoelectric actuator. Piezoelectric actuator (100) has first piezoelectric vibrator (102), second piezoelectric vibrator (104), and vibrating membrane (106). First piezoelectric vibrator (102) includes first pedestal (116) and first piezoelectric element (112) connected to the first pedestal. Second piezoelectric vibrator (104) includes second pedestal (118) and second piezoelectric element (114) connected to the second pedestal. Vibrating membrane (106) has opening (108). First piezoelectric vibrator (102) is connected to one surface of vibrating membrane (106) straddling opening (108) of the vibrating membrane. Second piezoelectric vibrator (102) is connected to another surface of vibrating membrane (106) straddling opening (108) of the vibrating membrane. ## Claims ### Claim 1 A piezoelectric actuator comprising: a first piezoelectric vibrator including a first pedestal and a first piezoelectric element connected to the first pedestal; a second piezoelectric vibrator including a second pedestal and a second piezoelectric element connected to the second pedestal; and a vibrating membrane having an opening, wherein said first piezoelectric vibrator is connected to one surface of said vibrating membrane straddling the opening of said vibrating membrane, and said second piezoelectric vibrator is connected to another surface of said vibrating membrane straddling the opening of said vibrating membrane. ### Claim 2 (depends on 1) The piezoelectric actuator according to claim 1, wherein rigidity of said vibrating membrane is smaller than rigidity of said pedestal. ### Claim 3 (depends on 1) The piezoelectric actuator according to claim 1, further comprising a support body that supports an outer edge portion of said vibrating membrane. ### Claim 4 (depends on 1) The piezoelectric actuator according to claim 1, wherein the one surface of said vibrating membrane is connected to a surface of said first pedestal to which said first piezoelectric element is not connected, and the other surface of said vibrating membrane is connected to a surface of said second pedestal to which said second piezoelectric element is not connected. ### Claim 5 (depends on 4) The piezoelectric actuator according to claim 4, wherein at least one of said first pedestal and said second pedestal is plate-shaped, and a periphery of the plate-shaped pedestal and a vicinity of the opening of said vibrating membrane are connected to each other. ### Claim 6 (depends on 1) The piezoelectric actuator according to claim 1, further comprising a driving device that independently drives said first piezoelectric element and said second piezoelectric element. ### Claim 7 (depends on 1) The piezoelectric actuator according to claim 1, wherein said first piezoelectric vibrator and said second piezoelectric vibrator have the same resonance frequency as each other. ### Claim 8 (depends on 1) The piezoelectric actuator according to claim 1, wherein said first piezoelectric vibrator and said second piezoelectric vibrator have resonance frequencies different from each other. ### Claim 9 (depends on 3) The piezoelectric actuator according to claim 3, wherein rigidity of a portion of said vibrating membrane supported by said support body is smaller than rigidity of the vicinity of the opening of said vibrating membrane. ### Claim 10 (depends on 3) The piezoelectric actuator according to claim 3, wherein said support body sandwiches the outer edge portion of said vibrating membrane through a low rigidity member having smaller rigidity than said vibrating membrane. ### Claim 11 (depends on 1) The piezoelectric actuator according to claim 1, wherein at least one of said first piezoelectric element and said second piezoelectric element has an opening. ### Claim 12 (depends on 1) The piezoelectric actuator according to claim 1, wherein at least one of said first pedestal and said second pedestal has an opening. ### Claim 13 (depends on 1) The piezoelectric actuator according to claim 1, wherein at least one of said first pedestal and said second pedestal is plate-shaped, a projecting portion protruding in a direction from a center of said pedestal toward an outside is formed in the periphery of the plate-shaped pedestal, the plate-shaped pedestal straddles the opening of said vibrating membrane, and the projecting portion is connected to said vibrating membrane. ### Claim 14 (depends on 1) The piezoelectric actuator according to claim 1, wherein at least one of said first pedestal and said second pedestal is plate-shaped, and the plate-shaped pedestal has a petal shape. ### Claim 15 (depends on 1) The piezoelectric actuator according to claim 1, wherein said first piezoelectric vibrator and said second piezoelectric vibrator vibrate in a direction perpendicular to a membrane surface of said vibrating membrane. ### Claim 16 (depends on 1) An audio component comprising the piezoelectric actuator according to claim 1, and emitting sound by bending vibration of the piezoelectric actuator. ### Claim 17 (depends on 16) The audio component according to claim 16, emitting sound by vibrations of said vibrating membrane that comprises said piezoelectric actuator.