US3646280A - Backplate for electret loudspeaker - Google Patents
Backplate for electret loudspeaker Download PDFInfo
- Publication number
- US3646280A US3646280A US67187A US3646280DA US3646280A US 3646280 A US3646280 A US 3646280A US 67187 A US67187 A US 67187A US 3646280D A US3646280D A US 3646280DA US 3646280 A US3646280 A US 3646280A
- Authority
- US
- United States
- Prior art keywords
- electret
- electroacoustic transducer
- vibrating film
- electrets
- electrostatic electroacoustic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/01—Electrostatic transducers characterised by the use of electrets
- H04R19/013—Electrostatic transducers characterised by the use of electrets for loudspeakers
Definitions
- ABSTRACT An electrostatic electroacoustic transducer comprising a vibrating film, an electret having many small holes and a fixed electrode adhered closely thereto.
- the fixed electrode is made of an electroconductive fiber.
- This invention relates to an electrostatic electroacoustic transducer, and more particularly to an improvement of an electrostatic electroacoustic transducer using an electret and electroconductive fiber.
- FIG. 1 is a sectional plane view of a prior art electrostatic electroacoustic transducer using an electret.
- FIG. 2 is a sectional plane view of the structure of an electrostatic electroacoustic transducer of the preferred embodiment of the present invention.
- electrostatic electroacoustic transducers using an electret for example a push-pull speaker, are constructed as shown in FIG. 1.
- a vibrating film 1 is located between charged electrets 2 and 3.
- Fixed electrodes 4 and 5 which are made of electroconductive materials are adhered closely to electrets 2 and 3 respectively. They are firmly held in place by holding members 6 and 7.
- an alternating signal is applied between the fixed electrode 4 or 5 and an electrode 10
- the vibrating film l is vibrated whereby the sound generated is radiated through holes 8 and 9.
- FIG. 2 wherein the preferred embodiment of the present in- .vention is shown.
- Numeral l1 designates a vibrating film
- the electroconductive fiber may be, for example, a carbon fiber, a graphite fiber, a metal fiber, or a nonelectroconductive fiber such as a glass fiber which is coated with metal or carbon so as to make it electroconductive. Further, these fibers can be used singly or can be mixed with other nonelectroconductive fibers. Usually, these fibers are used as cloth being composed of single or mixed fibers ina sheet, net or felt, which is hereinafter referred to as "a fiber.”
- 16 and 17 are insulated pressing boards having many holes 16a and 17a for the acoustic radiation.
- 18 and 19 are rings having screw portions and 19a, whereby the fibers 14 and 15 are pressed toward the electrets 12 and 13 through the pressing boards 16 and I7.
- Holding members 20 and 21 are made of insulated materials and hold above-mentioned components in place and have screw portions 20a and 21a whereby rings 18 and 19 are secured.
- An electrode 22 applies a signal into the vibrating film ll
- electrode 23 applies a signal into the fiber l4
- electrode 24 applies a signal into the fiber 15.
- the electrets 12 and 13 can be manufactured with many holes, having no relation to the fibers l4 and 15 which are the fixed electrodes.
- the fibers l4 and 15 are between the electrets l2 and 13 and the pressing boards 16 and 17, it is not necessary to make the hole 12a precisely coincide with hole 16a and the hole 13a with hole 17a. Therefore problems in making both holes precisely coincide are solved and the level of efficiency of mass production is raised.
- the fixed electrode the fibers l4 and 15
- the electrode can be pressed with the electret 12 or 13 equally on its whole surface.
- the acoustic characteristics can be selected by changing the elasticity or thickness or length of the fibers l4 and 15, or by adjusting the pressure ofthe pressing board 16 or 17 with the ring 18 or 19. Ifit is unnecessary to adjust the pressure of the pressing board 16 and 17, rings 18 or 19 may be omitted and the pressing board 16 or 17 may be fixed to the holding member 20 or 21. In such case, the level of efficiency of mass production is further increased. Fifth, it is not necessary to provide a dustproof layer since the electrets l2 and 13 are kept free of dust by fibers l4 and 15. Therefore, the charge on the electrets lasts for many years.
- An electrostatic electroacoustic transducer comprising a vibrating film, an electret having one side juxtapositioned to said vibrating film said electret having a plurality of holes therein for passing acoustic radiation, a fixed electrode made of an electroconductive fiber which is adhered to the other side of said electret, and a pressing board pushing said fixed electrode against said electret, said pressing board having a plurality of holes therein for passing acoustic radiation.
- An electrostatic electroacoustic transducer comprising a vibrating film, two electets each having one side juxtapositioned to said vibrating film each electret having a plurality of holes therein for passing acoustic radiation, fixed electrodes made of an electroconductive fiber said electrodes adhered to the other side of each of said electrets, and pressing boards pushing said fixed electrodes against said electrets, said pressing boards having a plurality of holes therein for passing acoustic radiation.
- electrostatic electroacoustic transducer as set forth in claim 1, wherein said electroconductive fiber is a carbon fiber.
- electrostatic electroacoustic transducer as set forth in claim 2, wherein said electroconductive fiber is a carbon fiber.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP44067613A JPS4815867B1 (US07655688-20100202-C00010.png) | 1969-08-28 | 1969-08-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3646280A true US3646280A (en) | 1972-02-29 |
Family
ID=13349963
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US67187A Expired - Lifetime US3646280A (en) | 1969-08-28 | 1970-08-26 | Backplate for electret loudspeaker |
Country Status (6)
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3787642A (en) * | 1971-09-27 | 1974-01-22 | Gte Automatic Electric Lab Inc | Electrostatic transducer having resilient electrode |
US3894199A (en) * | 1969-11-19 | 1975-07-08 | Pioneer Electronic Corp | Electret electrostatic electroacoustic transducer |
US3894198A (en) * | 1971-11-04 | 1975-07-08 | Kureha Chemical Ind Co Ltd | Electrostatic-piezoelectric transducer |
US3894333A (en) * | 1972-09-08 | 1975-07-15 | Uniroyal Ltd | Electromechanical transducer and method of making same |
US3896274A (en) * | 1973-10-04 | 1975-07-22 | Thermo Electron Corp | Electret earphone |
US20060072770A1 (en) * | 2004-09-22 | 2006-04-06 | Shinichi Miyazaki | Electrostatic ultrasonic transducer and ultrasonic speaker |
US20090016551A1 (en) * | 2007-07-12 | 2009-01-15 | Industrial Technology Research Institute | Electrostatic electroacoustic transducers |
US20100177926A1 (en) * | 2007-03-23 | 2010-07-15 | Sennheiser Electronic Gmbh & Co. Kg | Capacitive Electroacoustic Transducer and Microphone |
US20110033079A1 (en) * | 2009-08-10 | 2011-02-10 | Industrial Technology Research Institute | Flat loudspeaker structure |
US20110146056A1 (en) * | 2009-12-23 | 2011-06-23 | Industrial Technology Research Institute | Method and device of manufacturing speaker |
US20120002826A1 (en) * | 2010-06-30 | 2012-01-05 | Tsung-Hung Wu | Electret electroacoustic transducer |
US20120014543A1 (en) * | 2010-07-15 | 2012-01-19 | Taiwan Electrets Electronics Co., Ltd. | Electrostatic speaker and manufacturing method thereof and conductive backplate of the speaker |
US20150023529A1 (en) * | 2013-07-18 | 2015-01-22 | Infineon Technologies Ag | MEMS Devices, Interface Circuits, and Methods of Making Thereof |
US20160157022A1 (en) * | 2012-12-20 | 2016-06-02 | The Regents Of The University Of California | Electrostatic graphene speaker |
US20220278267A1 (en) * | 2019-07-12 | 2022-09-01 | National Institute Of Advanced Industrial Science And Technology | Sound pressure-electrical signal conversion device and conversion method for same |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2330800C3 (de) * | 1973-06-16 | 1981-10-01 | Sennheiser Electronic Kg, 3002 Wedemark | Elektroakustischer Wandler nach dem elektrostatischen Prinzip und Verfahren zu dessen Herstellung |
JP5262288B2 (ja) * | 2007-09-27 | 2013-08-14 | ヤマハ株式会社 | 静電型スピーカ |
US8300858B2 (en) | 2007-09-27 | 2012-10-30 | Yamaha Corporation | Electrostatic speaker |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1469120A (fr) * | 1964-12-28 | 1967-02-10 | Matsushita Electric Ind Co Ltd | Microphone à condensateur |
US3373251A (en) * | 1965-02-23 | 1968-03-12 | Shure Bros | Electrostatic transducer |
-
1969
- 1969-08-28 JP JP44067613A patent/JPS4815867B1/ja active Pending
-
1970
- 1970-08-24 ZA ZA705815A patent/ZA705815B/xx unknown
- 1970-08-26 CA CA091665A patent/CA933277A/en not_active Expired
- 1970-08-26 US US67187A patent/US3646280A/en not_active Expired - Lifetime
- 1970-08-27 GB GB4134270A patent/GB1318734A/en not_active Expired
- 1970-08-28 FR FR7031537A patent/FR2059726B1/fr not_active Expired
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3894199A (en) * | 1969-11-19 | 1975-07-08 | Pioneer Electronic Corp | Electret electrostatic electroacoustic transducer |
US3787642A (en) * | 1971-09-27 | 1974-01-22 | Gte Automatic Electric Lab Inc | Electrostatic transducer having resilient electrode |
US3894198A (en) * | 1971-11-04 | 1975-07-08 | Kureha Chemical Ind Co Ltd | Electrostatic-piezoelectric transducer |
US3894333A (en) * | 1972-09-08 | 1975-07-15 | Uniroyal Ltd | Electromechanical transducer and method of making same |
US3896274A (en) * | 1973-10-04 | 1975-07-22 | Thermo Electron Corp | Electret earphone |
US20060072770A1 (en) * | 2004-09-22 | 2006-04-06 | Shinichi Miyazaki | Electrostatic ultrasonic transducer and ultrasonic speaker |
US7668323B2 (en) * | 2004-09-22 | 2010-02-23 | Seiko Epson Corporation | Electrostatic ultrasonic transducer and ultrasonic speaker |
US20100177926A1 (en) * | 2007-03-23 | 2010-07-15 | Sennheiser Electronic Gmbh & Co. Kg | Capacitive Electroacoustic Transducer and Microphone |
US8406451B2 (en) * | 2007-03-23 | 2013-03-26 | Sennheiser Electronic Gmbh & Co. Kg | Capacitive electroacoustic transducer and microphone |
US20090016551A1 (en) * | 2007-07-12 | 2009-01-15 | Industrial Technology Research Institute | Electrostatic electroacoustic transducers |
US8559660B2 (en) * | 2007-07-12 | 2013-10-15 | Industrial Technology Research Institute | Electrostatic electroacoustic transducers |
US20110033079A1 (en) * | 2009-08-10 | 2011-02-10 | Industrial Technology Research Institute | Flat loudspeaker structure |
US8385586B2 (en) * | 2009-08-10 | 2013-02-26 | Industrial Technology Research Institute | Flat loudspeaker structure |
US20110146056A1 (en) * | 2009-12-23 | 2011-06-23 | Industrial Technology Research Institute | Method and device of manufacturing speaker |
US8322018B2 (en) * | 2009-12-23 | 2012-12-04 | Industrial Technology Research Institute | Method of manufacturing speaker |
US20120002826A1 (en) * | 2010-06-30 | 2012-01-05 | Tsung-Hung Wu | Electret electroacoustic transducer |
US20120014543A1 (en) * | 2010-07-15 | 2012-01-19 | Taiwan Electrets Electronics Co., Ltd. | Electrostatic speaker and manufacturing method thereof and conductive backplate of the speaker |
US8600083B2 (en) * | 2010-07-15 | 2013-12-03 | Taiwan Electrets Electronics Co., Ltd. | Electrostatic speaker and manufacturing method thereof and conductive backplate of the speaker |
US20140013581A1 (en) * | 2010-07-15 | 2014-01-16 | Taiwan Electrets Electronics Co., Ltd. | Electrostatic speaker and manufacturing method thereof and conductive backplate of the speaker |
US20160157022A1 (en) * | 2012-12-20 | 2016-06-02 | The Regents Of The University Of California | Electrostatic graphene speaker |
US10425742B2 (en) * | 2012-12-20 | 2019-09-24 | The Regents Of The University Of California | Electrostatic graphene speaker |
US10582305B2 (en) | 2012-12-20 | 2020-03-03 | The Regents Of The University Of California | Electrostatic graphene speaker |
US10771903B2 (en) | 2012-12-20 | 2020-09-08 | The Regents Of The University Of California | Electrostatic graphene speaker |
US11252512B2 (en) | 2012-12-20 | 2022-02-15 | The Regents Of The University Of California | Electrostatic graphene speaker |
US20150023529A1 (en) * | 2013-07-18 | 2015-01-22 | Infineon Technologies Ag | MEMS Devices, Interface Circuits, and Methods of Making Thereof |
US9179221B2 (en) * | 2013-07-18 | 2015-11-03 | Infineon Technologies Ag | MEMS devices, interface circuits, and methods of making thereof |
US20220278267A1 (en) * | 2019-07-12 | 2022-09-01 | National Institute Of Advanced Industrial Science And Technology | Sound pressure-electrical signal conversion device and conversion method for same |
Also Published As
Publication number | Publication date |
---|---|
DE2042351A1 (de) | 1972-03-02 |
DE2042351B2 (de) | 1972-07-27 |
CA933277A (en) | 1973-09-04 |
ZA705815B (en) | 1971-04-28 |
FR2059726B1 (US07655688-20100202-C00010.png) | 1974-04-26 |
JPS4815867B1 (US07655688-20100202-C00010.png) | 1973-05-17 |
FR2059726A1 (US07655688-20100202-C00010.png) | 1971-06-04 |
GB1318734A (en) | 1973-05-31 |
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