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WO2008029083A1 - Enceintes acoustiques à onde de flexion à panneaux - Google Patents

Enceintes acoustiques à onde de flexion à panneaux Download PDF

Info

Publication number
WO2008029083A1
WO2008029083A1 PCT/GB2007/003243 GB2007003243W WO2008029083A1 WO 2008029083 A1 WO2008029083 A1 WO 2008029083A1 GB 2007003243 W GB2007003243 W GB 2007003243W WO 2008029083 A1 WO2008029083 A1 WO 2008029083A1
Authority
WO
WIPO (PCT)
Prior art keywords
substrate
radiator
loudspeaker according
magnet
actuator
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.)
Ceased
Application number
PCT/GB2007/003243
Other languages
English (en)
Inventor
Geoffrey Arthur Coleridge Boyd
Martin Colloms
Neil Harris
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.)
NVF Tech Ltd
Original Assignee
New Transducers Ltd
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 New Transducers Ltd filed Critical New Transducers Ltd
Publication of WO2008029083A1 publication Critical patent/WO2008029083A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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
    • H04R7/02—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
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/04—Plane diaphragms
    • H04R7/06—Plane diaphragms comprising a plurality of sections or layers
    • H04R7/10—Plane diaphragms comprising a plurality of sections or layers comprising superposed layers in contact
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2499/00—Aspects covered by H04R or H04S not otherwise provided for in their subgroups
    • H04R2499/10—General applications
    • H04R2499/13—Acoustic transducers and sound field adaptation in vehicles

Definitions

  • the invention relates to bending wave panel-form loudspeakers and more particularly to such speakers comprising an electromagnetic actuator, in particular a moving coil actuator or transducer.
  • a known typical moving coil loudspeaker transducer or actuator comprises a coil assembly and a magnet assembly.
  • the coil assembly typically comprises a tubular former on which a coil is wound helically and the magnet assembly typically comprises a magnet coupled to inner and outer yokes of magnetic flux conductive material which yokes together define an air gap in which the coil assembly is suspended for axial movement.
  • the moving coil assembly in an actuator or transducer of this kind is sometimes known as a voice coil.
  • a bending wave loudspeaker having a panel-form acoustic radiator and an electromagnetic actuator coupled to drive the radiator in bending to produce an acoustic output
  • the actuator comprising a magnet assembly comprising a magnet mounted to a substantially planar pole piece, a coil assembly comprising a substantially planar voice coil mounted on a substantially planar rigid substrate, means suspending the substrate adjacent to the magnet assembly whereby the magnet lies adjacent to the voice coil with an air gap between the voice coil and the magnet, and wherein the substrate is mounted to or is integral with the radiator whereby the actuator can drive the radiator.
  • the magnet assembly may comprise an annular magnet and a disc-like pole piece.
  • the substrate may be disc-like and the suspending means may be positioned centrally of the pole piece and the substrate.
  • the loudspeaker may comprise coupling means connected between the substrate and the radiator.
  • the coupling means may be annular and may be concentric with and positioned on the substrate to be adjacent to the voice coil.
  • the coupling means is arranged on the substrate to be substantially in line with the resultant of electromagnetic forces to attenuate the effects of resonant modes generated in the substrate in operation of the actuator.
  • the suspending means may be disposed at the peripheral edges of the pole piece and the substrate.
  • the loudspeaker may comprise coupling means connected between the substrate and the radiator, the coupling means being positioned centrally of the actuator.
  • the loudspeaker may comprise first and second concentric voice coils mounted on the substrate.
  • the loudspeaker may comprise first and second concentric magnets on the pole piece.
  • the first and second voice coils may be associated with a single magnet on the pole piece.
  • the first and second magnets may be associated with a single voice coil on the substrate.
  • the suspending means may provide a clamped support .
  • the suspending means may provide a compliant suspension.
  • the magnet assembly may comprise a first pair of magnets and a second pair of magnets adjacent to the first pair of magnets, with a first magnet in each pair mounted to a first pole piece and a second magnet in each pair mounted to a second pole piece such that a planar air gap is defined between the first and second magnets in each pair and in which the coil assembly is suspended for movement.
  • Both the first and second pair of magnets may be axially oriented and the first pair of magnets may have an opposite polarisation to the second pair of magnets .
  • the magnet assembly may comprise at least three pairs of magnets with adjacent pairs having opposite polarisations and the voice coil assembly having a number of voice coils corresponding to the number of magnet pairs .
  • the magnetic material of the magnets may be epoxy compression bonded NdFeB (BHmax 10MGOe) .
  • the magnet or magnets may employ shaped field techniques to improve flux density.
  • the or each pole piece may be formed directly by the magnet itself.
  • the magnets may be annular "ring” magnets which are coaxially mounted about a central axis of the actuator.
  • the substrate may be annular and coaxially mounted about the central axis.
  • the substrate may be compliantly suspended on the magnet assembly at or adjacent to its inner periphery and coupled to the radiator at or adjacent to its outer periphery.
  • the magnets may have a trapezium shaped cross-section.
  • the coil assembly may extend into the radiator whereby the actuator is coupled to the radiator.
  • the substrate may be a printed circuit board on which the voice coils are printed. Multi-layer printed circuit boards are also possible with the voice coil being printed on more than one of the layers .
  • the substrate may be made from a material of high thermal conductivity.
  • the substrate may be of non-uniform thickness such that its bending behaviour is controlled.
  • the radiator may be a composite panel comprising a core sandwiched between two skins and the actuator may be mounted in a cavity in the core .
  • the invention is a bending wave loudspeaker actuator as described above.
  • the invention is panel-form vehicle trim e.g. a roof or headlining comprising a loudspeaker as described above.
  • the invention is a greetings card comprising a loudspeaker as described above and wherein the greetings card has a self-supporting leaf forming the radiator.
  • the number of voice coils and/or magnets affects the performance and cost of the actuator. If cost is a more significant factor than performance, the number may advantageously be reduced.
  • the substrate is rigid in the sense that it is at least self-supporting and its rigidity may be enhanced by making it from a cored composite material .
  • the substrate may be wholly planar but it might be slightly shaped, e.g. by dishing or corrugating, e.g. with radial corrugations, to improve its rigidity so as to control its bending behaviour.
  • the magnetic material of the magnets may be epoxy compression bonded NdFeB (BHmax 10MGOe) . Alternatively, the lower cost high throughput injection moulded NdFeB magnet material may be used.
  • the use of substantially flat voice coils allows the actuator to have a low profile and may have a depth as low as 1.5mm. Such a design is suitable for incorporating into greetings cards, packaging and novelty applications and other applications where depth is limited, such as in the provision of speakers in or utilising the interior trim panels of vehicles such as the head-linings of automobiles.
  • the coil assembly may be compliantly suspended or clamped on the first and/or second pole pieces via foamed plastics blocks.
  • This clamped or compliant suspension can be at the inner periphery of the substrate where it is annular but conceivably the suspension might alternatively be at its outer periphery.
  • the coupling to the radiator may be via the outer periphery of the substrate or may be at another position on the substrate, e.g. at its inner periphery or at an intermediate position.
  • the coupling may be positioned adjacent to the position of the voice coil or coils on the substrate, with the object of positioning the coupling substantially in line with the resultant of the electromagnetic forces to attenuate the effects of the resonant modes generated in the substrate in operation of the actuator.
  • the voice coil assembly may extend into the structure of the radiator panel at the periphery of the substrate whereby the actuator is coupled to the radiator.
  • the substrate might be fixed to a face of the radiator panel at its outer periphery.
  • the voice coil or coils is or are printed on the substrate which is in the form of a printed circuit board, which printed circuit board may also carry additional electronics.
  • the voice coil or coils may be formed from rectangular section wire to increase packing density and hence sensitivity.
  • the voice coils may be formed from copper.
  • a metal of higher conductivity and/or reduced mass may be used.
  • the substrate may be made from non-magnetic materials, for example materials with higher thermal conductivity to facilitate removal of waste heat.
  • the substrate may be of uniform thickness. Alternatively, the substrate may have a varying and nonuniform thickness, such that the modal behaviour of the substrate is modified in a beneficial manner.
  • the radiator may be a composite panel comprising a high shear core sandwiched between two skins .
  • the actuator may be mounted within a cavity in the core.
  • the actuator has been described above in terms of a generally disc-like device, it might alternatively be formed as a strip-like device, e.g. to suit non-circular radiators, e.g. rectangular radiators.
  • the construction of the strip-like actuator can be regarded as a central diametric section taken from the generally disc-like actuator described above and in the drawings below.
  • the single sided actuator described above can be attractive.
  • Such an actuator has freedoms not available to the two sided actuator, resulting from the fact that the substrate is not obscured by a magnet cup or pole piece.
  • the output can be extracted at the edge of the substrate or via access holes in the cups or pole pieces .
  • Resonant modes generated in the substrate in use may affect the operation of the actuator.
  • Figure 1 is a partial cross-sectional side view of an embodiment bending wave panel-form loudspeaker of the present invention
  • Figure 2 is a plan view of an automobile roof or headlining, portions of which head-lining form loudspeakers of the kind shown in Figure 1 ;
  • Figure 3 is a diagrammatic partial cross-sectional side view of a second embodiment of bending wave panel-form loudspeaker of the invention.
  • Figure 4 is a partial plan view of the loudspeaker shown in Figure 3;
  • Figure 5 is a diagrammatic partial cross-sectional side view of a third embodiment of bending wave panel-form loudspeaker of the present invention.
  • Figure 6 is a partial plan view of the loudspeaker of Figure 5 ;
  • Figure 7 is a diagrammatic partial cross-sectional side view of a fourth embodiment of bending wave panel-form loudspeaker of the invention.
  • Figure 8 is a diagrammatic partial cross-sectional side view of a fifth embodiment of bending wave panel-form loudspeaker of the invention.
  • Figure 9 is a diagrammatic partial cross-sectional side view of a sixth embodiment of bending wave panel-form loudspeaker of the invention.
  • Figure 1 shows a partial cross-section of a bending wave panel-form loudspeaker 1 which may be of the distributed mode kind as exemplified in WO 97/09842 in the name of New Transducers Limited or of the balanced mode kind as exemplified in WO 2005/101899 in the name of New Transducers Limited.
  • the loudspeaker comprises a stiff lightweight panel radiator 2 to which is coupled a generally disc-shaped electromagnetic moving coil actuator 5 by means of an annular coupler 16. As is conventional for such moving coil devices, it is designed to convert electrical signals applied to the device into force applied to the radiator to drive bending waves into the radiator so that it radiates an acoustic output.
  • Figure 1 shows only one half of the actuator which is symmetrical about a central axis 17.
  • the actuator 5 comprises a disc-like magnet assembly 14 and a disc-like coil assembly 13 both of generally the same diameter and which are clamped together at their respective centres by clamping means, e.g. a threaded fastener or a rivet.
  • the magnet assembly comprises a pole piece 6 and is of a ferro-magnetic material, e.g. soft iron.
  • the pole piece is formed at its centre with a raised boss 18 whereby the pole piece is spaced from the coil assembly at positions away from their respective centres.
  • a radially outer portion of the pole piece is dished to form a cup 8 having a cavity facing the coil assembly and containing an annular magnet 7 fixed to the pole piece and extending close to the coil assembly with an air gap 19 there-between.
  • a resilient dust seal 10 is fixed between the peripheries of the magnet and coil assemblies to seal the actuator against the ingress of foreign matter.
  • the magnet is generally trapezoidal in cross-section.
  • the coil assembly comprises a rigid disc-like substrate 15, which may be a printed circuit board, on which are fixed a concentric pair of flat annular coils 11 and 12 respectively.
  • the coils are arranged on the substrate to face the magnet 7.
  • the coils may be printed on the substrate.
  • the coupler 16 is arranged on the opposite face of the substrate to that of the coils 11,12 and is positioned generally adjacent to the coils so that it is in line with the resultant of the force generated by the actuator. In this way, the actuator can apply the force to the radiator panel 2 more or less directly, so as to minimise the effects of resonant modes in the substrate in operation. It will be seen that the actuator of Figure 1 is slim in depth as compared to conventional moving coil actuators so as to minimise the total depth of the loudspeaker assembly.
  • Figure 2 shows a plan of a panel-form roof or headlining 3 for an automobile, the positions of four passengers in the automobile being represented by dashed lines 4.
  • Actuators 5, e.g. of the kind shown in Figure 1 are fixed to the outer or upper side of the headlining 3 so that they are not visible to the passengers and in groups of two in front of each passenger position to excite bending waves in the headlining to form bending wave panel-form loudspeakers at each passenger position.
  • the use of pairs of actuators at each passenger position permits spatial effects and/or stereo sound.
  • Figures 3 and 4 show a panel-form bending wave loudspeaker 1 of the same general kind as is shown in Figure 1 above.
  • a single annular coil 20 of the electromagnetic actuator 5 is fixed on the rigid substrate 15 opposite to the magnet 7 on the pole piece 6.
  • Figure 3 additionally shows lead wires 21,22 for coupling the coil 20 to a signal source.
  • Figures 5 and 6 show a panel-form bending wave loudspeaker 1 of the same general kinds as are described above with reference to Figures 1 to 4.
  • the electromagnetic actuator 5 comprises a pole piece 6 clamped to the substrate 15 at their respective peripheries by an annular member 24, which may be of a rigid foamed plastics material and the substrate is coupled to the panel-form radiator 2 by a centrally positioned coupler 23.
  • Figure 7 shows a panel-form bending wave loudspeaker 1 of the same general kind as is shown in Figures 5 and 6 but in the present case the actuator is coupled to the panel-form radiator at position in line with the magnet 7 and voice coil 20 by means of an annular coupler 16, of the kind used in the embodiments of Figures 1 and 3.
  • Figure 8 shows a variation of the loudspeaker shown in Figures 5 and 6 where the pole piece 6 carries a concentric pair of annular magnets 25,26 which cooperate with a single voice coil 20 on the substrate 15.
  • the bending wave panel-form loudspeaker arrangement of Figure 9 however comprises an actuator which can be described as “double sided” in that a pair of pole pieces are used to reduce magnetic flux leakage and improve loudness. This arrangement means that it is difficult to extract force from the actuator except via the outer peripheral edge of the moving coil assembly.
  • Figure 9 shows a panel-form bending wave loudspeaker 1 comprising a planar actuator 5 of the general kind described above with reference to Figures 1 to 8 , except that in this case it is double sided.
  • the actuator 5 is symmetrical about its central axis 17 and is embedded within a panel-form radiator 2.
  • the loudspeaker bending wave radiator 2 comprises a shear-resistant core 32 sandwiched between two high tensile skins 34,36 and the actuator 5 is mounted in a cavity 38 in the core 32.
  • the actuator comprises a magnet assembly 14 generally of the kind described above and comprising a pair of pole pieces 6 which are fixed together at their centres 46,47, e.g. by welding and which pole pieces surround a coil assembly 13 of the general kind described above.
  • the magnet assembly comprises a pair of low carbon steel pole pieces 6 each rigidly supporting three concentric annular magnets 52,54,56 to form three coaxial pairs of magnets.
  • the magnet assembly is not acoustically porous.
  • the magnets in each pair are separated by an annular planar air gap into which the coil assembly 13 is mounted.
  • Each magnet has a trapezium-shaped cross-section with the long parallel side mounted to the pole pieces and with the short parallel sides of each pair of magnets separated by the air gap.
  • Each magnet is axially oriented with the middle pair 54 of magnets having the opposite polarisation to the adjacent pairs 52,56.
  • the middle pair of magnets has a first face of a first magnetic polarity, e.g. north, adjacent the pole piece and a second face of a second opposite magnetic polarity, e.g. south, adjacent to the air gap.
  • the other two pairs 52,56 have a first face of a first magnetic polarity, e.g. north, adjacent the air gap and a second face of a second opposite magnetic polarity, e.g. south, adjacent the pole piece.
  • the coil assembly 13 comprises three concentric voice coils 40, 42, 44 printed on a self-supporting, that is to say rigid, annular planar substrate 45.
  • the substrate 45 is compliantly mounted to the upper and lower pole pieces by suspension blocks 66 of resilient foamed plastics material.
  • the substrate 45 extends into the core 32 of the radiator to couple the actuator to the radiator whereby the power from the actuator is delivered to the radiator.
  • the substrate may be a printed circuit board and may carry additional electronics.
  • the magnetic material of the magnets may be epoxy compression bonded NdFeB (BHmax 10MGOe) .
  • the material of the coil assembly substrate may be composite, e.g. comprising a cellular core and face skins. It is possible that the coil assembly substrate might be slightly dished or otherwise formed to improve or to modify its rigidity so as to control its resonant behaviour.
  • the loudspeaker of the present invention can be made very slim so that it is suitable for incorporating into greetings cards, packaging and novelty applications, and for use in association with panel-form vehicle trim, e.g. the roof trim or headlining of an automobile, to form a bending wave loudspeaker.
  • panel-form vehicle trim e.g. the roof trim or headlining of an automobile

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)

Abstract

L'invention concerne une enceinte acoustique à onde de flexion, qui comporte un élément rayonnant acoustique en forme de panneau et un actionneur électromagnétique couplé pour commander la flexion de l'élément rayonnant et produire une sortie acoustique. L'actionneur comprend: un ensemble aimant comprenant un aimant fixé à une pièce polaire sensiblement planaire; un ensemble bobine comprenant une bobine mobile sensiblement planaire installée sur un substrat rigide sensiblement planaire; un moyen de suspension du substrat adjacent à l'ensemble aimant dont l'aimant jouxte la bobine mobile, une lame d'air étant disposée entre la bobine mobile et l'aimant. Le substrat est fixé ou intégré à l'élément rayonnant, permettant ainsi à l'actionneur de commander l'élément rayonnant. L'ensemble aimant peut comprendre un aimant annulaire et une pièce polaire en forme de disque et le substrat peut pésenter la forme d'un disque. L'enceinte acoustique peut comprendre un moyen de couplage raccordé entre le substrat et l'élément rayonnant, et le moyen de couplage peut être annulaire et avoir le même centre que la bobine mobile à laquelle il est contigu. De préférence, le moyen de couplage peut être placé sur le substrat sensiblement en ligne avec la résultante de la force électromagnétique. Dans un aspect, on décrit un actionneur d'enceinte acoustique à onde de flexion. Dans un autre aspect, on décrit une assiette de véhicule en forme de panneau comprenant une enceinte acoustique de l'invention. Dans un autre aspect encore, on décrit une carte de voeux qui comprend une enceinte acoustique de l'invention et présente une lame autonome formant l'élément rayonnant.
PCT/GB2007/003243 2006-09-07 2007-08-29 Enceintes acoustiques à onde de flexion à panneaux Ceased WO2008029083A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0617551.7 2006-09-07
GB0617551A GB0617551D0 (en) 2006-09-07 2006-09-07 Electromagnetic actuator

Publications (1)

Publication Number Publication Date
WO2008029083A1 true WO2008029083A1 (fr) 2008-03-13

Family

ID=37232463

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2007/003243 Ceased WO2008029083A1 (fr) 2006-09-07 2007-08-29 Enceintes acoustiques à onde de flexion à panneaux

Country Status (2)

Country Link
GB (1) GB0617551D0 (fr)
WO (1) WO2008029083A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2471474A (en) * 2009-06-30 2011-01-05 New Transducers Ltd Method of making an actuator
US8958597B2 (en) 2012-03-23 2015-02-17 Coleridge Design Associates Llc Speaker with voice coil and field coil
RU2580217C1 (ru) * 2015-04-07 2016-04-10 Валентин Валерьевич Казанжи Электродинамический излучатель наушника (варианты)
KR20190094333A (ko) * 2016-12-27 2019-08-13 소니 주식회사 표시 장치
WO2020030239A1 (fr) * 2018-08-06 2020-02-13 Huawei Technologies Co., Ltd. Carte de circuit imprimé pour un dispositif électronique et dispositif électronique comprenant ladite carte de circuit imprimé
US11956589B1 (en) 2021-07-13 2024-04-09 Wisdom Audio Corp. PMD speaker mounting assembly and thermal control system for multiple drivers

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT381204B (de) * 1984-11-22 1986-09-10 Akg Akustische Kino Geraete Magnetsystem fuer elektrodynamische wandler, insbesondere mikrophone und kopfhoerer
WO1997009842A2 (fr) * 1995-09-02 1997-03-13 New Transducers Limited Dispositif acoustique
WO2000047013A1 (fr) * 1999-02-06 2000-08-10 New Transducers Limited Excitateur de vibrations conçu pour creer des vibrations d'ondes de flexion
US20020065113A1 (en) * 2000-11-28 2002-05-30 Ukyo Mori Electron device
GB2373399A (en) * 2000-12-20 2002-09-18 New Transducers Ltd Exciter for a bending wave loudspeaker includes elastomer between magnet and coil
WO2005117489A1 (fr) * 2004-05-27 2005-12-08 Matsushita Electric Industrial Co., Ltd. Haut-parleur
US20060182303A1 (en) * 2002-02-05 2006-08-17 Trandafir Roland P Microphone assembly

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT381204B (de) * 1984-11-22 1986-09-10 Akg Akustische Kino Geraete Magnetsystem fuer elektrodynamische wandler, insbesondere mikrophone und kopfhoerer
WO1997009842A2 (fr) * 1995-09-02 1997-03-13 New Transducers Limited Dispositif acoustique
WO2000047013A1 (fr) * 1999-02-06 2000-08-10 New Transducers Limited Excitateur de vibrations conçu pour creer des vibrations d'ondes de flexion
US20020065113A1 (en) * 2000-11-28 2002-05-30 Ukyo Mori Electron device
GB2373399A (en) * 2000-12-20 2002-09-18 New Transducers Ltd Exciter for a bending wave loudspeaker includes elastomer between magnet and coil
US20060182303A1 (en) * 2002-02-05 2006-08-17 Trandafir Roland P Microphone assembly
WO2005117489A1 (fr) * 2004-05-27 2005-12-08 Matsushita Electric Industrial Co., Ltd. Haut-parleur
EP1750477A1 (fr) * 2004-05-27 2007-02-07 Matsushita Electric Industrial Co., Ltd. Haut-parleur

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2471474A (en) * 2009-06-30 2011-01-05 New Transducers Ltd Method of making an actuator
GB2471474B (en) * 2009-06-30 2014-11-19 New Transducers Ltd Actuator
US8958597B2 (en) 2012-03-23 2015-02-17 Coleridge Design Associates Llc Speaker with voice coil and field coil
RU2580217C1 (ru) * 2015-04-07 2016-04-10 Валентин Валерьевич Казанжи Электродинамический излучатель наушника (варианты)
WO2016163918A1 (fr) * 2015-04-07 2016-10-13 Валентин Валерьевич КАЗАНЖИ Émetteur électrodynamique d'une oreillette
US20190268681A1 (en) * 2016-02-27 2019-08-29 Sony Corporation Display Apparatus
US11659309B2 (en) 2016-02-27 2023-05-23 Sony Group Corporation Display apparatus
KR20190094333A (ko) * 2016-12-27 2019-08-13 소니 주식회사 표시 장치
EP3565275A4 (fr) * 2016-12-27 2020-01-08 Sony Corporation Dispositif d'affichage
KR102376136B1 (ko) 2016-12-27 2022-03-18 소니그룹주식회사 표시 장치
US11356759B2 (en) 2016-12-27 2022-06-07 Sony Group Corporation Display apparatus
WO2020030239A1 (fr) * 2018-08-06 2020-02-13 Huawei Technologies Co., Ltd. Carte de circuit imprimé pour un dispositif électronique et dispositif électronique comprenant ladite carte de circuit imprimé
CN112292871A (zh) * 2018-08-06 2021-01-29 华为技术有限公司 用于电子设备的印刷线路板和包括所述印刷线路板的电子设备
CN112292871B (zh) * 2018-08-06 2021-12-28 华为技术有限公司 包括改进的印刷线路板的电子设备
US11956589B1 (en) 2021-07-13 2024-04-09 Wisdom Audio Corp. PMD speaker mounting assembly and thermal control system for multiple drivers

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