WO2002023946A3 - Flat loudspeaker - Google Patents

Flat loudspeaker Download PDF

Info

Publication number
WO2002023946A3
WO2002023946A3 PCT/EP2001/010492 EP0110492W WO0223946A3 WO 2002023946 A3 WO2002023946 A3 WO 2002023946A3 EP 0110492 W EP0110492 W EP 0110492W WO 0223946 A3 WO0223946 A3 WO 0223946A3
Authority
WO
WIPO (PCT)
Prior art keywords
panel
sound
modes
flexural
loudspeaker
Prior art date
Application number
PCT/EP2001/010492
Other languages
German (de)
French (fr)
Other versions
WO2002023946A2 (en
Inventor
Oskar Bschorr
Hans-Joachim Raida
Original Assignee
Oskar Bschorr
Hans-Joachim Raida
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 Oskar Bschorr, Hans-Joachim Raida filed Critical Oskar Bschorr
Priority to AU2002213902A priority Critical patent/AU2002213902A1/en
Publication of WO2002023946A2 publication Critical patent/WO2002023946A2/en
Publication of WO2002023946A3 publication Critical patent/WO2002023946A3/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/26—Damping by means acting directly on free portion of diaphragm or cone
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/04—Plane diaphragms
    • H04R7/045—Plane diaphragms using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2440/00—Bending wave transducers covered by H04R, not provided for in its groups
    • H04R2440/01—Acoustic transducers using travelling bending waves to generate or detect sound

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)

Abstract

The invention relates to a flat loudspeaker (10) comprised of a flexible panel (11) serving as a sound transmitter. The rear side of the panel is acoustically separated by a box (14). By virtue of the system and thanks to the comparatively large panel surface, the box depth is extremely small compared to that of a conventional piston-type loudspeaker, hence the name flat loudspeaker. Flexural waves are induced inside the panel by an electrodynamic oscillator (12) analogous to that in a piston-type loudspeaker and, together with the reflections on the panel edge, form a standing wave field. The interaction with the surrounding air causes sound to be radiated. This simplicity is obtained at the cost of a series of drawbacks. The density of the flexural wave modes is relatively wide-meshed thus resulting in a poor oscillatory and acoustic frequency response. The reverberation is disruptive. Directivity and radiation efficiency also pose a problem. The maxima and minima of the flexural wave modes destructively interfere and only the oscillation differential thereof provides useful sound. These drawbacks are avoided by effecting a termination by using impedance transmitters (14). In particular, the wave components traveling outward with the flexural wave velocity are eliminated. The positioning and the spectral frequency response of the impedance transmitters (14) enable the simultaneous fixing of evanescent, i.e. non-traveling modes, and likewise enable the spectral adjustment of a priori fixed near-fields in the area of the oscillators. Evanescent modes and the near-fields are resonance-free, oscillate in a conphasal manner, and are optimized here as a sound transmitter. By eliminating the sound radiation of the traveling waves, the coincidence condition does not apply, the panel (10) decreases in size, disruptive sound extinctions no longer occur thus obtaining an improved directivity.
PCT/EP2001/010492 2000-09-18 2001-09-11 Flat loudspeaker WO2002023946A2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2002213902A AU2002213902A1 (en) 2000-09-18 2001-09-11 Flat loudspeaker

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2000146059 DE10046059A1 (en) 2000-09-18 2000-09-18 Flat speaker
DE10046059.3 2000-09-18

Publications (2)

Publication Number Publication Date
WO2002023946A2 WO2002023946A2 (en) 2002-03-21
WO2002023946A3 true WO2002023946A3 (en) 2003-10-16

Family

ID=7656591

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2001/010492 WO2002023946A2 (en) 2000-09-18 2001-09-11 Flat loudspeaker

Country Status (3)

Country Link
AU (1) AU2002213902A1 (en)
DE (1) DE10046059A1 (en)
WO (1) WO2002023946A2 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004028664A1 (en) * 2004-06-12 2006-01-19 Puren Gmbh Vibration body of a speaker system
DE102006039452A1 (en) * 2006-08-23 2008-03-13 Puren Gmbh Panel loudspeaker device
DE102006039454A1 (en) * 2006-08-23 2008-03-13 Puren Gmbh Planar loudspeaker device for use in compact disc player, has passive filter unit provided for integration into building wall and exhibiting adjusting unit with adjusting values designed for predetermined surface layers on surface diaphragm
DE102006051401B3 (en) * 2006-10-27 2007-11-22 Daimlerchrysler Ag Loudspeaker e.g. cone loudspeaker, unit for e.g. hands free set, has housing, whose dimensions, dimensions and position of opening are selected so that negative interference of acoustic signals is formed transverse to normal of loudspeaker
EP3416340B1 (en) 2006-12-26 2020-10-21 Dali Systems Co., Ltd. Method and system for baseband predistortion linearization in multi-channel wideband communication systems
DE102007030811A1 (en) 2007-04-26 2008-11-06 Airbus Deutschland Gmbh Flat speaker
EP1988740A1 (en) * 2007-05-03 2008-11-05 Nederlandse Organisatie voor toegepast- natuurwetenschappelijk onderzoek TNO Sound generator
DE102011078355B3 (en) * 2011-06-29 2012-10-11 Siemens Aktiengesellschaft Capacitive sensor element for detecting a displacement with a plurality of electrode pairs and method for its operation
US11057710B2 (en) 2017-06-09 2021-07-06 Ask Industries Societa' Per Azioni Loudspeaker structure
DE102019106685B4 (en) * 2019-03-15 2021-01-21 Hochschule für Angewandte Wissenschaften Hamburg Sound absorber with a Helmholtz resonator
JP7269135B2 (en) * 2019-08-29 2023-05-08 フォルシアクラリオン・エレクトロニクス株式会社 vibration output device

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2112516B1 (en) * 1971-03-16 1972-10-19 Kurtze Guenther Dipl Phys Prof Directional loudspeaker
DE4335087A1 (en) * 1992-10-20 1994-04-21 Gyoergy Csikos Conversion of mechanical vibration in acoustic signals and converter - uses flexible plastic plate suspended at centre in contact with driver and having specified material, dimensions and suspension

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2112516B1 (en) * 1971-03-16 1972-10-19 Kurtze Guenther Dipl Phys Prof Directional loudspeaker
DE4335087A1 (en) * 1992-10-20 1994-04-21 Gyoergy Csikos Conversion of mechanical vibration in acoustic signals and converter - uses flexible plastic plate suspended at centre in contact with driver and having specified material, dimensions and suspension

Also Published As

Publication number Publication date
WO2002023946A2 (en) 2002-03-21
AU2002213902A1 (en) 2002-03-26
DE10046059A1 (en) 2002-03-28

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