US3894199A - Electret electrostatic electroacoustic transducer - Google Patents

Electret electrostatic electroacoustic transducer Download PDF

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Publication number
US3894199A
US3894199A US090771A US9077170A US3894199A US 3894199 A US3894199 A US 3894199A US 090771 A US090771 A US 090771A US 9077170 A US9077170 A US 9077170A US 3894199 A US3894199 A US 3894199A
Authority
US
United States
Prior art keywords
electrets
electroacoustic transducer
electrostatic electroacoustic
vibrating film
terminal
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
Application number
US090771A
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English (en)
Inventor
Masahiko Tamura
Kiyonori Iwama
Mitsuo Asahina
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pioneer Corp
Original Assignee
Pioneer Electronic Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Pioneer Electronic Corp filed Critical Pioneer Electronic Corp
Application granted granted Critical
Publication of US3894199A publication Critical patent/US3894199A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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 push-pull type transducer wherein a vibrating film is not connected to any signal terminal.
  • One terminal of a step-up transformer is connected to one fixed electrode, and the other terminal of the transformer is connected to another fixed electrode.
  • This invention relates generally to an electrostatic electroacoustic transducer, and more particularly to a novel and improved push-pull type transducer using an electret.
  • Prior art push-pull electrostatic electroacoustic transducers such as a speaker, generally comprise a vibrating film, two electrodes and a holding member which holds the vibrating film between the two electrodes. A polarization voltage is applied to the film and a potential is applied across the electrodes through a step-up transformer.
  • the prior art devices have many disadvantages.
  • the polarization voltage E is large and therefore a larger conductor for the polarizing voltage is required.
  • the step-up transformer must be provided with a center tap to boost and divide an input signal and to place opposing potentials on the fixed electrodes.
  • a vibrating film must be connected to the center tap of the step-up transformer.
  • FIG. 1 is a sectional plan view of a prior art push-pull electrostatic electroacoustic transducer showing its principle.
  • FIG. 2 is a sectional plan view of a push-pull electrostatic electroacoustic transducer of the preferred embodiment of the present invention.
  • FIG. 1 Prior art push-pull type electrostatic electroacoustic transducers are constructed as shown in FIG. 1.
  • a vibrating film 13 is positioned between the electrodes.
  • Fixed electrodes 12 have many holes which pass the acoustic radiation.
  • a polarization voltage E0 is applied across the vibrating film l3 and each fixed electrode through a step-up transformer 14 and a resistor R0.
  • the primary winding of the step-up transformer 14 is connected to a signal source 15.
  • the potential of both fixed electrodes is supplied by an alternating signal of the signal source 15.
  • the potential of the two fixed electrodes is opposing. That is, when one is positive, the other is negative.
  • fixed electrodes 21 and 22 face each other. They comprise back electrodes 211 and 221, and electrets 212 and 222 which are affixed to the back electrodes.
  • the fixed electrodes 21 and 22 have many holes which pass acoustic radiation. The potential of the facing surfaces of the two electrets is same.
  • a vibrating film 23 is positioned between the fixedelectrodes 21 and 22. The vibrating film 23 is electroconductive at least at its surface.
  • Holding member 24 is made of an insulated material, and holds the fixed electrodes 21 and 22 and the vibrating film 23.
  • One terminal of the secondary winding of step-up transformer 25 is connected to the fixed electrode 21, and the other terminal is connected to the fixed electrode 22.
  • a signal source 26 is connected to the primary winding of step-up transformer 25.
  • both surfaces of the vibrating film 23 are negative.
  • the vibrating film 23 assumes a negative charge because it has an electroconductive surface and is positioned between the two positively charged electrets.
  • an alternating signal from signal source 26 is stepped-up by transformer 25 and applied to the fixed electrodes 21 and 22, the positive potential of one electret, for example electret 212, is increased and that of the other electret is decreased during a half cycle of the signal.
  • the vibrating film 23 is biased toward the electret 212.
  • the vibrating film 23 is biased toward the other electret 222. This process is cyclicly repeated, vibrating film 23.
  • the vibrating film 23 is not connected electrically to the electrets.
  • the present invention gives many improvements over prior art devices.
  • An electrostatic electroacoustic transducer comprising first and second electrets positioned to face each other, said electrets having identical potentials on their-facing surfaces, first and second back electrodes affixed to said first and second electrets, a vibrating film positioned between said electrets, said film being electroconductive on its surface, and a signal source wherein one terminal of said source is connected to said first back electrode and the other terminal is connected to said second back electrode.
  • An electrostatic electroacoustic transducer is set forth in claim 1, further comprising a holding means for holding said electrets, said back electrodes and said vibrating film.
  • An electrostatic electroacoustic transducer comprising first and second electrets positioned to face each other, said electrets being identically charged on facing surfaces, first and second back electrodes affixed to said first and second electrets, a vibrating film positioned between said electrets, said film being electroconductive on its surface, a step-up transformer having a primary and secondary winding wherein one terminal of the secondary winding is connected to said first back electrode and the other terminal of said secondary Winding is connected to said second back electrode, and a signal source connected to said primary winding of said step-up transformer.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
US090771A 1969-11-19 1970-11-18 Electret electrostatic electroacoustic transducer Expired - Lifetime US3894199A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP44092079A JPS4840084B1 (fr) 1969-11-19 1969-11-19

Publications (1)

Publication Number Publication Date
US3894199A true US3894199A (en) 1975-07-08

Family

ID=14044426

Family Applications (1)

Application Number Title Priority Date Filing Date
US090771A Expired - Lifetime US3894199A (en) 1969-11-19 1970-11-18 Electret electrostatic electroacoustic transducer

Country Status (7)

Country Link
US (1) US3894199A (fr)
JP (1) JPS4840084B1 (fr)
CA (1) CA949674A (fr)
DE (1) DE2055683B2 (fr)
FR (1) FR2067388A1 (fr)
GB (1) GB1302430A (fr)
ZA (1) ZA707721B (fr)

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3942029A (en) * 1973-07-23 1976-03-02 Sony Corporation Electrostatic transducer
EP0008237A1 (fr) * 1978-08-10 1980-02-20 Shigeo Okubo Détecteur pour générer des signaux électriques représentatifs pour des déplacements relatifs
US5097515A (en) * 1988-11-30 1992-03-17 Matsushita Electric Industrial Co., Ltd. Electret condenser microphone
US20040113526A1 (en) * 2001-04-11 2004-06-17 Kari Kirjavainen Electromechanical transducer and method for transforming energies
US20060072770A1 (en) * 2004-09-22 2006-04-06 Shinichi Miyazaki Electrostatic ultrasonic transducer and ultrasonic speaker
US20060182293A1 (en) * 2004-09-16 2006-08-17 Hirokazu Sekino Ultrasonic transducer, ultrasonic speaker, acoustic system, and control method of ultrasonic transducer
EP1718107A2 (fr) * 2005-04-28 2006-11-02 Panphonics Oy Transducteur électrostatique,son procédé de connexion et procédé de fabrication
US20090016551A1 (en) * 2007-07-12 2009-01-15 Industrial Technology Research Institute Electrostatic electroacoustic transducers
US20090060234A1 (en) * 2007-09-04 2009-03-05 Industrial Technology Research Institute Speaker structure
US20090067648A1 (en) * 2007-09-06 2009-03-12 Industrial Technology Research Institute Structure and manufactruring method of electrostatic speaker
US20090154730A1 (en) * 2007-12-14 2009-06-18 Sony Ericsson Mobile Communications Ab Electrostatic Speaker Arrangement for a Mobile Device
US20100024198A1 (en) * 2008-08-01 2010-02-04 Industrial Technology Research Institute Methods of making speakers
US20100104116A1 (en) * 2008-10-24 2010-04-29 Industrial Technology Research Institute Flat speaker unit and speaker device therewith
US20100158284A1 (en) * 2008-12-18 2010-06-24 Industrial Technology Research Institute Assembly structure of a flat speaker
US20100208932A1 (en) * 2009-02-13 2010-08-19 Industrial Technology Research Institute Multi-directional flat speaker device
US20100260370A1 (en) * 2009-04-09 2010-10-14 Industrial Technology Research Institute Flat speaker structure
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
US20120106761A1 (en) * 2010-11-03 2012-05-03 Industrial Technology Research Institute Driving interface device adaptive to a flat speaker
US8625824B2 (en) 2007-09-04 2014-01-07 Industrial Technology Research Institute Flat speaker unit and speaker device therewith
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
WO2014100012A1 (fr) * 2012-12-20 2014-06-26 The Regents Of The University Of California Haut-parleur en graphène électrostatique
US20160164433A1 (en) * 2014-12-04 2016-06-09 Samsung Display Co., Ltd. Piezoelectric element including mesoporous piezoelectric thin film

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA989514A (en) * 1972-09-08 1976-05-18 Loh-Yi Chang Electromechanical transducer and method of making same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3118022A (en) * 1961-08-07 1964-01-14 Bell Telephone Labor Inc Electroacoustic transducer
US3474197A (en) * 1964-10-24 1969-10-21 Tesla Np Electret microphone
US3646280A (en) * 1969-08-28 1972-02-29 Pioneer Electronic Corp Backplate for electret loudspeaker

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3118022A (en) * 1961-08-07 1964-01-14 Bell Telephone Labor Inc Electroacoustic transducer
US3474197A (en) * 1964-10-24 1969-10-21 Tesla Np Electret microphone
US3646280A (en) * 1969-08-28 1972-02-29 Pioneer Electronic Corp Backplate for electret loudspeaker

Cited By (52)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3942029A (en) * 1973-07-23 1976-03-02 Sony Corporation Electrostatic transducer
EP0008237A1 (fr) * 1978-08-10 1980-02-20 Shigeo Okubo Détecteur pour générer des signaux électriques représentatifs pour des déplacements relatifs
US5097515A (en) * 1988-11-30 1992-03-17 Matsushita Electric Industrial Co., Ltd. Electret condenser microphone
US7376239B2 (en) * 2001-04-11 2008-05-20 Panphonics Oy Electromechanical transducer and method for transforming energies
US20040113526A1 (en) * 2001-04-11 2004-06-17 Kari Kirjavainen Electromechanical transducer and method for transforming energies
CN1750716B (zh) * 2004-09-16 2011-12-21 精工爱普生株式会社 超声波扬声器、声学系统以及超声波换能器的控制方法
US20060182293A1 (en) * 2004-09-16 2006-08-17 Hirokazu Sekino Ultrasonic transducer, ultrasonic speaker, acoustic system, and control method of ultrasonic transducer
US7949143B2 (en) * 2004-09-16 2011-05-24 Seiko Epson Corporation Ultrasonic transducer, ultrasonic speaker, acoustic system, and control method of ultrasonic transducer
US7542579B2 (en) * 2004-09-16 2009-06-02 Seiko Epson Corporation Ultrasonic transducer, ultrasonic speaker, acoustic system, and control method of ultrasonic transducer
US20090202088A1 (en) * 2004-09-16 2009-08-13 Seiko Epson Corporation Ultrasonic transducer, ultrasonic speaker, acoustic system, and control method of ultrasonic transducer
US7668323B2 (en) * 2004-09-22 2010-02-23 Seiko Epson Corporation Electrostatic ultrasonic transducer and ultrasonic speaker
US20060072770A1 (en) * 2004-09-22 2006-04-06 Shinichi Miyazaki Electrostatic ultrasonic transducer and ultrasonic speaker
EP1718107A2 (fr) * 2005-04-28 2006-11-02 Panphonics Oy Transducteur électrostatique,son procédé de connexion et procédé de fabrication
EP1718107A3 (fr) * 2005-04-28 2010-10-27 Panphonics Oy Transducteur électrostatique,son procédé de connexion et procédé de fabrication
US8559660B2 (en) 2007-07-12 2013-10-15 Industrial Technology Research Institute Electrostatic electroacoustic transducers
US20090016551A1 (en) * 2007-07-12 2009-01-15 Industrial Technology Research Institute Electrostatic electroacoustic transducers
US8625824B2 (en) 2007-09-04 2014-01-07 Industrial Technology Research Institute Flat speaker unit and speaker device therewith
US8107651B2 (en) 2007-09-04 2012-01-31 Industrial Technology Research Institute Speaker structure
US20090060234A1 (en) * 2007-09-04 2009-03-05 Industrial Technology Research Institute Speaker structure
US20090067648A1 (en) * 2007-09-06 2009-03-12 Industrial Technology Research Institute Structure and manufactruring method of electrostatic speaker
US8155356B2 (en) 2007-09-06 2012-04-10 Industrial Technology Research Institute Structure and manufacturing method of electrostatic speaker
US20090154730A1 (en) * 2007-12-14 2009-06-18 Sony Ericsson Mobile Communications Ab Electrostatic Speaker Arrangement for a Mobile Device
US8184833B2 (en) * 2007-12-14 2012-05-22 Sony Ericsson Mobile Communications Ab Electrostatic speaker arrangement for a mobile device
US20100027814A1 (en) * 2008-08-01 2010-02-04 Industrial Technology Research Institute Speaker devices
US20100024198A1 (en) * 2008-08-01 2010-02-04 Industrial Technology Research Institute Methods of making speakers
US8196282B2 (en) * 2008-08-01 2012-06-12 Industrial Technology Research Institute Methods of making speakers
US8139794B2 (en) 2008-08-01 2012-03-20 Industrial Technology Research Institute Speaker devices
US8391520B2 (en) 2008-10-24 2013-03-05 Industrial Technology Research Institute Flat speaker unit and speaker device therewith
US20100104116A1 (en) * 2008-10-24 2010-04-29 Industrial Technology Research Institute Flat speaker unit and speaker device therewith
US8243966B2 (en) 2008-12-18 2012-08-14 Industrial Technology Research Institute Assembly structure of a flat speaker
US20100158284A1 (en) * 2008-12-18 2010-06-24 Industrial Technology Research Institute Assembly structure of a flat speaker
US20100208932A1 (en) * 2009-02-13 2010-08-19 Industrial Technology Research Institute Multi-directional flat speaker device
US8126189B2 (en) 2009-02-13 2012-02-28 Industrial Technology Research Institute Multi-directional flat speaker device
US8594349B2 (en) 2009-04-09 2013-11-26 Industrial Technology Research Institute Flat speaker structure
US20100260370A1 (en) * 2009-04-09 2010-10-14 Industrial Technology Research Institute Flat speaker structure
US8385586B2 (en) 2009-08-10 2013-02-26 Industrial Technology Research Institute Flat loudspeaker structure
US20110033079A1 (en) * 2009-08-10 2011-02-10 Industrial Technology Research Institute Flat loudspeaker structure
US8322018B2 (en) 2009-12-23 2012-12-04 Industrial Technology Research Institute Method of manufacturing speaker
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
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
US20120106761A1 (en) * 2010-11-03 2012-05-03 Industrial Technology Research Institute Driving interface device adaptive to a flat speaker
US8588438B2 (en) * 2010-11-03 2013-11-19 Industrial Technology Research Institute Driving interface device adaptive to a flat speaker
US20160157022A1 (en) * 2012-12-20 2016-06-02 The Regents Of The University Of California Electrostatic graphene speaker
WO2014100012A1 (fr) * 2012-12-20 2014-06-26 The Regents Of The University Of California Haut-parleur en graphène électrostatique
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
US20220159387A1 (en) * 2012-12-20 2022-05-19 The Regents Of The University Of California Electrostatic graphene speaker
US20160164433A1 (en) * 2014-12-04 2016-06-09 Samsung Display Co., Ltd. Piezoelectric element including mesoporous piezoelectric thin film
US10937944B2 (en) 2014-12-04 2021-03-02 Samsung Display Co., Ltd. Piezoelectric element including mesoporous piezoelectric thin film

Also Published As

Publication number Publication date
ZA707721B (en) 1971-08-25
DE2055683A1 (de) 1971-06-03
JPS4840084B1 (fr) 1973-11-28
DE2055683B2 (de) 1972-10-05
GB1302430A (fr) 1973-01-10
CA949674A (en) 1974-06-18
FR2067388A1 (fr) 1971-08-20

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