# US 8,148,879 B2 · Sheet-type vibrator and acoustic apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,148,879 B2 - Document ID: US8148879B2 - Status: Granted - Kind: B2 - Application number: 12/954,726 - Filed: 2010-11-26 - Published: 2011-03-17 - Granted: 2012-04-03 - Earliest claimed: 2008-05-29 - Assignees: Murata Manufacturing Co., Ltd. - Inventors: Masamichi Andoh; Osamu Nakagawara; Souko Fukahori - Web page: https://patentgrep.com/patent/US8148879B2 ## CPC - H10N 30/204: {using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders} - H04R 17/005: {using a piezoelectric polymer} - H10N 30/857: Macromolecular compositions - H10N 30/871: {Single-layered electrodes of multilayer piezoelectric or electrostrictive devices, e.g. internal electrodes} - H10N 30/878: {the principal material being non-metallic, e.g. oxide or carbon based} - H04R 2499/11: Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's - Y10S 310/80: Piezoelectric polymers, e.g. PVDF - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - 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) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract In a sheet-type piezoelectric vibrator provided with a piezoelectric sheet made from a transparent organic polymer and electrodes formed on respective main surfaces that are opposite to each other of the piezoelectric sheet, an electrode material that is effectively used for making the vibrator colorless is provided. The first electrodes formed on one of the main surfaces of piezoelectric sheets are made of zinc oxide electrode layers, each mainly containing zinc oxide, and second electrodes formed on the other main surface of the piezoelectric sheets include polythiophene electrode layers made from a conductive polymer containing thiophene in a molecule structure thereof. Although the zinc oxide electrode layer is transparent, it is slightly yellowish, while, on the other hand, although the polythiophene electrode layer is also transparent, it is slightly bluish. Since the spectral characteristic of light transmitted through these two electrode layers is made substantially flat in the visible region, the coloring of the transmitted light is suppressed so that the layers appear colorless and transparent. ## Claims ### Claim 1 A sheet-type vibrator comprising: a functional sheet made from a transparent organic polymer; and first and second electrodes respectively located on first and second main surfaces of the functional sheet, wherein the first electrode includes a zinc oxide electrode layer mainly containing zinc oxide, and the second electrode includes a polythiophene electrode layer made from a conductive polymer containing thiophene in a molecule structure thereof. ### Claim 2 (depends on 1) The sheet-type vibrator according to claim 1, wherein a plurality of the functional sheets are laminated together such that the first and second main surfaces of adjacent functional sheets are opposed to each other. ### Claim 3 (depends on 1) The sheet-type vibrator according to claim 1, further comprising: a backing sheet attached to the functional sheet with the first electrode interposed therebetween, the backing sheet comprising a transparent organic polymer. ### Claim 4 (depends on 1) The sheet-type vibrator according to claim 1, wherein the first electrode is the zinc oxide electrode layer, and the second electrode is the polythiophene electrode layer. ### Claim 5 (depends on 1) The sheet-type vibrator according to claim 1, wherein the second electrode also includes the zinc oxide electrode layer, and the first electrode also includes the polythiophene electrode layer. ### Claim 6 (depends on 5) The sheet-type vibrator according to claim 5, wherein the zinc oxide electrode layers are located proximal to the functional sheet, and the polythiophene electrode layers are located distal from the functional sheet relative to the zinc oxide electrode layers. ### Claim 7 (depends on 1) The sheet-type vibrator according to claim 1, further comprising: a second functional sheet made from the transparent organic polymer; and third and fourth electrodes respectively located on first and second main surfaces of the second functional sheet, wherein the third electrode includes a zinc oxide electrode layer mainly containing zinc oxide, and the fourth electrode includes a polythiophene electrode layer made from a conductive polymer containing thiophene in a molecule structure thereof, wherein the functional sheet and the second functional sheet are arranged in a manner such that the first and third electrodes are adjacent each other, and the second and fourth electrodes are on outer sides of their respective functional sheets. ### Claim 8 (depends on 1) The sheet-type vibrator according to claim 1, wherein the zinc oxide electrode layer has a crystalline form in which c-axes are grown in a plurality of directions that are mutually different from one another. ### Claim 9 (depends on 1) The sheet-type vibrator according to claim 1, wherein the zinc oxide electrode layer includes zinc oxide doped with at least one kind selected from the group consisting of Ga, Al and In at a doping concentration in a range from 7 to 40% by weight in terms of each oxide conversion. ### Claim 10 (depends on 1) The sheet-type vibrator according to claim 1, wherein the conductive polymer containing thiophene in a molecule structure thereof is polyethylene dioxythiophene. ### Claim 11 (depends on 1) An acoustic apparatus comprising the sheet-type vibrator according to claim 1. ### Claim 12 A sheet-type vibrator comprising: a plurality of laminated functional sheets, the functional sheets comprising a transparent organic polymer; and electrodes located on respective main surfaces opposite to each other of each of the functional sheets, wherein a first set of the electrodes include a zinc oxide electrode layer mainly containing zinc oxide, and a second set of the electrodes include a polythiophene electrode layer made from a conductive polymer containing thiophene in a molecule structure thereof. ### Claim 13 (depends on 12) The sheet-type vibrator according to claim 12, wherein the plurality of the functional sheets are three, and the three functional sheets are arranged so that the electrodes on the respective main surfaces of a center functional sheet of the three functional sheets comprise the first set of electrodes, and the electrodes on the respective main surfaces of outer functional sheets of the three functional sheets comprise the second set of electrodes. ### Claim 14 (depends on 12) The sheet-type vibrator according to claim 12, wherein each of the functional sheets is a piezoelectric sheet. ### Claim 15 (depends on 10) The sheet-type vibrator according to claim 10, wherein the organic polymer is polylactate. ### Claim 16 (depends on 8) The sheet-type vibrator according to claim 8, wherein the zinc oxide electrode layer has a crystalline form in which c-axes are grown in a plurality of directions that are mutually different from one another. ### Claim 17 (depends on 8) The sheet-type vibrator according to claim 8, wherein the zinc oxide electrode layer includes zinc oxide doped with at least one kind selected from the group consisting of Ga, Al and In at a doping concentration in a range from 7 to 40% by weight in terms of each oxide conversion. ### Claim 18 (depends on 8) The sheet-type vibrator according to claim 8, wherein the conductive polymer containing thiophene in a molecule structure thereof is polyethylene dioxythiophene. ### Claim 19 (depends on 8) An acoustic apparatus comprising: the sheet-type vibrator according to claim 8.