EP0085997A2 - Akustischer Wandler - Google Patents

Akustischer Wandler Download PDF

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Publication number
EP0085997A2
EP0085997A2 EP83200058A EP83200058A EP0085997A2 EP 0085997 A2 EP0085997 A2 EP 0085997A2 EP 83200058 A EP83200058 A EP 83200058A EP 83200058 A EP83200058 A EP 83200058A EP 0085997 A2 EP0085997 A2 EP 0085997A2
Authority
EP
European Patent Office
Prior art keywords
films
zones
transducer according
film
transducer
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.)
Withdrawn
Application number
EP83200058A
Other languages
English (en)
French (fr)
Other versions
EP0085997A3 (de
Inventor
Preston Vincent Murphy
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.)
Lectret SA
Original Assignee
Lectret SA
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 Lectret SA filed Critical Lectret SA
Publication of EP0085997A2 publication Critical patent/EP0085997A2/de
Publication of EP0085997A3 publication Critical patent/EP0085997A3/de
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/005—Details of transducers, loudspeakers or microphones using digitally weighted transducing elements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S310/00—Electrical generator or motor structure
    • Y10S310/80—Piezoelectric polymers, e.g. PVDF

Definitions

  • the present invention relates to an acoustic transducer comprising a hollow support and a plurality of metallized piezoelectric polymer films operating as an oscillator, said films being mounted at their peripheries on the hollow support so that their peripheries are separated and they are physically connected in the vicinity of their center at at least one film adjacent said transducer being designed to produce sound, said films being electrically connected and their polarities selected so that the films move in the same direction when they are electrically excited.
  • piezoelectric film transducer typically produces a lower amplitude than that produced, with the same voltage, by other types of transducers such as electrodynamic transducers. This lower voltage sensitivity can lead to an undesirably low amplitude for certain applications, such as telephone receivers, or the signal voltage is low.
  • piezoelectric film transducers used as microphones or transmitters produce a lower output voltage for a given sound pressure than other types of transducers, such as electret capacitors. Such low output voltages require the use of relatively high cost gain amplifiers.
  • the binary words composing the digital signal must be transformed into a series of discrete pulses, the amplitude of which corresponds to the quantization levels represented by the binary word, and then proceed to analog electrical fiberizing. to the frequency band of the desired sound signal and finally to the transduction of the electrical analog signal into an analog sound signal.
  • the present invention allows the production of a transducer which directly converts an electrical digital signal into an analog sound signal.
  • This acoustic transducer according to the invention is characterized in that one face of at least one of said films is composed of metallized zones whose size of their surfaces is staggered and electrically isolated from each other and that an zone or a group of areas where a film is selectively excited by an electrical signal so that a digital electrical signal is directly converted into an audio signal composed of amplitude-modulated pulses.
  • the metallized zones are concentric circular rings of the circle sector, nested spirals or crossed bands.
  • the zone is caused to move, which produces a sound signal whose amplitude depends on the surface of said zone.
  • the superposition of these signals reconstitutes the analog sound signal after an acoustic filtering of the signal obtained at the output of the transducer.
  • the single figure represents a vertical section of an earpiece according to the invention.
  • an earpiece composed of two piezoelectric films.
  • the films in the form of truncated cones 14 and 16 are connected at their center by epoxy adhesive 18 and mounted at their periphery on a cylindrical support between rings not shown.
  • the films 14 and 16 consist of layers 28 of polarized polyvinylidene, 9 microns thick which are metallized on their surfaces by a layer 30 of gold with a thickness of 200 o A.
  • the films are polarized to obtain a high piezoelectric coefficient in the two directions (X and Y) of the film surface (commonly denoted d 31 and d so that the films deform symmetrically which effectively improves the result.
  • polarization of the films 14 and 16 are aligned perpendicular to the surfaces of the films, and the films are mounted such that the two vectors are directed in the same direction.
  • the film 16 is metallized on one of its faces in three bands 6,7,8 in the form of concentric rings.
  • the strip 6 can be a solid disc, that is to say that the metallization can extend over the central part of the film 16 to which it is bonded to the film 14.
  • the film 14 is metallized continuously over almost all its surface.
  • the metallized surface 6 is approximately half the surface of the ring 7, the quarter of the ring 8 and approximately the eighth of the surface 9 of the film 14.
  • the interior faces 11 and 13 of the two films 14 and 16 are metallized continuously and connected to ground.
  • the binary digital signal to be converted into an analog sound signal is composed of binary words of five parallel bits, each bit having a different weight from the others.
  • the bits are transmitted by lines 1 to 5.
  • Line 1 transmitting the most significant bit and 5 the least significant bit. The most significant bit also determines the sign of the binary word.
  • Line 1 defines the sign of the displacement and it is connected either to a positive voltage source or negative by a switch, line 2 is connected to surface 9, line 3 to surface 8, line 4 to surface 7, line 5 to surface 6.
  • the surfaces excited by the lines transmitting the different bits are scaled according to the powers of two, thus allowing the decoding of a linearly coded signal with pulse modulation (PCM).
  • PCM pulse modulation
  • the sound pulse generated by the excitation of a zone or group of metallized zones is associated with the weight of the corresponding bit.
  • the voltage applied to each metallized surface is constant, so it is only the size of the displaced surface that influences the amplitude of the sound pulse.
  • the acoustic superposition of the sound pulses generated by the different excited surfaces produces an acoustic pulse of amplitude corresponding to the value of the original binary word; an analog acoustic filter allows the transformation into analog sound signal.
  • the number of bits can be 4.5.6 or more depending on the quality of the desired audio signal.
  • the sign bit could be linked to the second side of the films.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)
  • Circuit For Audible Band Transducer (AREA)
EP83200058A 1982-02-09 1983-01-14 Akustischer Wandler Withdrawn EP0085997A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8202531A FR2521382A2 (fr) 1982-02-09 1982-02-09 Transducteur acoustique
FR8202531 1982-02-09

Publications (2)

Publication Number Publication Date
EP0085997A2 true EP0085997A2 (de) 1983-08-17
EP0085997A3 EP0085997A3 (de) 1984-07-18

Family

ID=9271033

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83200058A Withdrawn EP0085997A3 (de) 1982-02-09 1983-01-14 Akustischer Wandler

Country Status (4)

Country Link
US (1) US4469920A (de)
EP (1) EP0085997A3 (de)
JP (1) JPS58143698A (de)
FR (1) FR2521382A2 (de)

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3437488A1 (de) * 1984-10-12 1986-04-17 Richard Wolf Gmbh, 7134 Knittlingen Schallsender
US4833360A (en) * 1987-05-15 1989-05-23 Board Of Regents The University Of Texas System Sonar system using acoustically transparent continuous aperture transducers for multiple beam beamformation
US5185549A (en) * 1988-12-21 1993-02-09 Steven L. Sullivan Dipole horn piezoelectric electro-acoustic transducer design
WO1991010334A1 (en) * 1990-01-03 1991-07-11 David Sarnoff Research Center, Inc. Acoustic transducer and method of making the same
JP3377173B2 (ja) * 1998-02-16 2003-02-17 松下電器産業株式会社 ディジタル式電気音響変換器
US7915789B2 (en) * 2005-03-21 2011-03-29 Bayer Materialscience Ag Electroactive polymer actuated lighting
US7952261B2 (en) 2007-06-29 2011-05-31 Bayer Materialscience Ag Electroactive polymer transducers for sensory feedback applications
EP2239793A1 (de) 2009-04-11 2010-10-13 Bayer MaterialScience AG Elektrisch schaltbarer Polymerfilmaufbau und dessen Verwendung
WO2012118916A2 (en) 2011-03-01 2012-09-07 Bayer Materialscience Ag Automated manufacturing processes for producing deformable polymer devices and films
JP2014517331A (ja) 2011-03-22 2014-07-17 バイエル・インテレクチュアル・プロパティ・ゲゼルシャフト・ミット・ベシュレンクテル・ハフツング 電場応答性高分子アクチュエータレンチキュラシステム
US9876160B2 (en) 2012-03-21 2018-01-23 Parker-Hannifin Corporation Roll-to-roll manufacturing processes for producing self-healing electroactive polymer devices
KR20150031285A (ko) 2012-06-18 2015-03-23 바이엘 인텔렉쳐 프로퍼티 게엠베하 연신 공정을 위한 연신 프레임
US9590193B2 (en) 2012-10-24 2017-03-07 Parker-Hannifin Corporation Polymer diode
TWI595789B (zh) * 2016-02-16 2017-08-11 智動全球股份有限公司 電聲轉換器

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1967130C2 (de) * 1968-01-25 1982-04-01 Pioneer Electronic Corp., Tokyo Mechanisch-elektrisch bzw. elektrisch-mechanischer Wandler
JPS4926890B1 (de) * 1970-12-04 1974-07-12
CH539845A (de) * 1972-06-30 1973-07-31 Ibm Elektroakustischer Wandler
US4242541A (en) * 1977-12-22 1980-12-30 Olympus Optical Co., Ltd. Composite type acoustic transducer
US4295010A (en) * 1980-02-22 1981-10-13 Lectret S.A. Plural piezoelectric polymer film acoustic transducer

Also Published As

Publication number Publication date
JPS58143698A (ja) 1983-08-26
FR2521382A2 (fr) 1983-08-12
EP0085997A3 (de) 1984-07-18
US4469920A (en) 1984-09-04

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Effective date: 19850319

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Inventor name: MURPHY, PRESTON VINCENT