WO2012093058A1 - Electroacoustic transducer - Google Patents

Electroacoustic transducer Download PDF

Info

Publication number
WO2012093058A1
WO2012093058A1 PCT/EP2011/074123 EP2011074123W WO2012093058A1 WO 2012093058 A1 WO2012093058 A1 WO 2012093058A1 EP 2011074123 W EP2011074123 W EP 2011074123W WO 2012093058 A1 WO2012093058 A1 WO 2012093058A1
Authority
WO
WIPO (PCT)
Prior art keywords
coil
electroacoustic transducer
circuit board
flexible circuit
transducer
Prior art date
Application number
PCT/EP2011/074123
Other languages
French (fr)
Inventor
Heribert Bauer
Stefan Leitner
Original Assignee
Knowles Electronics Asia Pte. 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 Knowles Electronics Asia Pte. Ltd. filed Critical Knowles Electronics Asia Pte. Ltd.
Publication of WO2012093058A1 publication Critical patent/WO2012093058A1/en

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00Diaphragms for electromechanical transducers; Cones
    • H04R7/02Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/04Plane diaphragms
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/02Details
    • H04R9/04Construction, mounting, or centering of coil

Definitions

  • the invention relates to an electro-acoustic transducer comprising a membrane and a magnet system.
  • the invention relates to the construction of micro speakers.
  • Micro speakers are loudspeakers mainly used in mobile applications such as mobile phones, mp3 players, navigation systems, laptops etc.
  • micro speakers The key to the success of micro speakers is high performance and high reliability at a very low total cost level.
  • the voice coil One difficulty in the miniaturisation and cost reduction results from the electrical connection that needs to be made to a moving component (the voice coil).
  • the connection is made with loop wires.
  • the voice coil is glued to the membrane.
  • the loop wires at the ends of the voice coils are formed and guided to the fixed part of the speaker, where they are soldered/thermo bonded to contact springs.
  • the loop wires are formed from the same material as the voice coil and move during the operation of the speaker. These moving loop wires are a critical aspect of the reliability of the speaker. This loop wire arrangement also requires a number of components dedicated specifically to the electrical connection.
  • an electro-acoustic transducer comprising a diaphragm, a coil attached to the diaphragm and a permanent magnet arrangement, wherein the magnetic field of the permanent magnet arrangement interacts with the coil electromagnetic field,
  • the diaphragm comprises a flexible circuit board, wherein electrical and mechanical connection is made between the flexible circuit board and the coil.
  • a flexible circuit board enables the diaphragm movement, and also enables fixed electrical connections to be made to the coil.
  • the flexible circuit board preferably comprises a flexible foil printed circuit board.
  • the flexible circuit board can comprise an outer frame, an inner diaphragm part and suspension members extending between the outer frame and the inner diaphragm part.
  • the suspension members thus provide the physical flexibility as well as providing conductor tracks to the outer frame.
  • the electrical connection off the flexible board can then be at the static outer frame part of the board.
  • the inner diaphragm part can be a solid shape. This means the flexible board itself is providing the mechanical diaphragm. In another arrangement, the inner diaphragm part has a central opening over which is provided a plate. The plate then functions as the mechanical diaphragm.
  • suspension members extending between the corners of a generally rectangular inner diaphragm part and corners of a larger generally rectangular outer frame.
  • the coil is preferably annular and positioned at the edge of the inner diaphragm part.
  • Figure 1 shows, in cross-section, a known electroacoustic transducer
  • Figure 2 shows a first example of voice coil suspension arrangement for use in a transducer of the invention
  • Figure 3 shows a second example of voice coil suspension arrangement for use in a transducer of the invention
  • Figure 4 shows the arrangement of components in cross section
  • Figure 5 shows a dual voice coil arrangement
  • Figure 6 shows a third example of voice coil suspension arrangement for use in a transducer of the invention
  • Figure 7 shows a fourth example of voice coil suspension arrangement for use in a transducer of the invention
  • Figure 8 shows a fifth example of voice coil suspension arrangement for use in a transducer of the invention.
  • the invention provides an electroacoustic transducer (speaker or microphone) having a coil attached to a diaphragm and a permanent magnet arrangement.
  • the diaphragm comprises a flexible circuit board, wherein electrical and mechanical connection is made between the flexible circuit board and the coil. This provides a simple mechanical and electrical connection for the coil with low component count and cost and with good reliability.
  • Figure 1 shows a known electroacoustic transducer 1 as described in
  • the transducer 1 is essentially centrally symmetrical in design, and has a transducer axis 2.
  • the transducer 1 has a pot-shaped housing 3, which is made of metal and which has a base wall 4 and a side wall 5.
  • the base wall 4 is provided with a circular elevation 6, in which sound transmission openings are provided (not shown).
  • the pot- shaped housing 3 can have a height of 1 -5mm and the diameter of housing 3 in the direction running perpendicular to the direction of transducer axis 2 is for example in the range 5- 20mm.
  • the transducer 1 is for example provided for use in a mobile telephone or in similar small scale telecommunications apparatus.
  • the transducer 1 contains a membrane 8, which is essentially U-shaped in its peripheral area 9.
  • the U-shaped peripheral area 9 is connected to a ring 10, which is connected to the membrane 8 when the membrane 8 is produced.
  • the ring 10 is for transport purposes and also for assembly purposes.
  • the ring 10 including the membrane 8 which is connected to it, is inserted into the housing 3 in parallel with the direction of transducer axis 2, before the lugs 7 have been bent over.
  • the outer part of the membrane is fixed in position.
  • the membrane 8 has an intermediate area 1 1 adjacent to the U-shaped peripheral area 9, and an annular securing area 12 adjacent to intermediate area 1 1 .
  • a central area 13 is located within the securing area 12, and the central area 13 is for sound generation.
  • the membrane 8 as a whole is arranged parallel to transducer axis 2 so as to be oscillatory.
  • the transducer 1 is further equipped with a magnet system 14.
  • the magnet system 14 comprises a permanent magnet 15 and an annular first yoke 16, which yoke 16 is located tight against the permanent magnet 15.
  • a second yoke 17 has an L-shaped cross-sectional shape, and a disk-shaped first section 18 of the second yoke 17 is also located tight against the permanent magnet 15.
  • An annular second section 19 protrudes from first section 18 parallel with transducer axis 2.
  • the first yoke 16, then the permanent magnet 15 and then the second yoke 17 are inserted into the housing 3 parallel with the direction of transducer axis 2.
  • the lugs 7 of housing 3 are bent over into their positions as shown in Figure 1 , as a result of which the membrane 8 and the magnet system 14 are fixed.
  • An air gap 20 is formed between the free end of second section 19 of the second yoke 17 and the inner edge of the first yoke 16, which air gap 20 is bounded by the two components of the magnet system, namely the first yoke 16 and the second yoke 17.
  • the magnet system 14 encloses an inner space 22.
  • Fixed in the inner space 22 is a contact carrier 24 made of plastic and provided to hold two moving-coil contacts 25, only one of which moving-coil contacts 25 is visible in Figure 1 owing to the sectional view.
  • the moving-coil contacts 25 are connected to the contact carrier 24 by means of extrusion.
  • the transducer 1 contains a moving coil 29 (the voice coil), which is partly arranged in air gap 20 and is connected to the membrane 8 in its securing area 12 using an adhesive connection.
  • the moving coil 29 interacts with the magnet system 14, wherein an electrical signal representing a signal to be reproduced acoustically is sent to the moving coil 29, as a result of which the moving coil 29 is caused to oscillate, which results in the membrane 8 bringing about the signal to be reproduced acoustically.
  • the electrical signal sent to moving coil 29 must be amplified and, if applicable, its signal waveform must be influenced, before being sent to the moving coil 29.
  • An integrated circuit 31 for this purpose is indicated schematically in Figure 1 .
  • the invention relates particularly to the way the voice coil 29 is mounted and electrically connected.
  • the invention can be applied to a microphone similar in design to that shown in Figure 1 , but it can be applied to other designs.
  • Figure 1 is provided simply to show an example of the typical arrangement of components.
  • Figure 1 The relevant aspects of the design of Figure 1 are that there is a voice coil attached to a diaphragm, and a permanent magnet arrangement.
  • the magnetic field of the permanent magnet arrangement interacts with the voice coil electromagnetic field.
  • the invention provides a transducer in which the diaphragm comprises a flexible circuit board, wherein electrical and mechanical connection is made between the flexible circuit board and the voice coil.
  • FIG. 2 shows a first design from the underside.
  • the flexible circuit board 40 preferably comprises a flexible foil printed circuit board.
  • the flexible circuit board comprises an outer frame 42, an inner diaphragm part 44 and suspension members 46 extending between the outer frame and the inner diaphragm part.
  • the suspension members 46 thus provide the physical flexibility as well as providing conductor tracks to the outer frame.
  • the corners of the outer frame can be provided with electrical contacts to the control circuitry, and the flexible circuit board 40 provides the electrical connections to the voice coil 29.
  • the outer frame is fixed as in the example of Figure 1 .
  • the electrical connection off the flexible board is thus at the static outer frame part of the board.
  • the inner diaphragm part can be a solid shape, as shown in Figure 2. This means the flexible board itself is providing the mechanical diaphragm.
  • the inner diaphragm part 44 has a central opening 50 over which is provided a plate. The plate then functions as the mechanical diaphragm.
  • electrical connections from the voice coil 29 to the circuit board are at connection points 52 which are positioned within the shape of the voice coil.
  • suspension members there are four suspension members extending between the corners of a generally rectangular inner diaphragm part 44 and corners of a larger generally rectangular outer frame 42.
  • a different shape can be used.
  • the voice coil 29 is annular and positioned around the edge of the inner diaphragm part 44. There may be two concentric annular voice coils, adjacent each other, and both positioned around the edge of the inner diaphragm part. Dual voice coil speakers are known. The use of dual voice coils enables different amplification systems to be used, for example boost bridge amplifiers. The additional connections required to two voice coils has been a problem in the past.
  • Figure 4 shows the arrangement of components in cross section.
  • the voice coil 29 is provided with short circuit rings 33.
  • the voice coil is surrounded by the permanent magnet 15, the first yoke 16 which functions as a pole plate, and the second yoke 17.
  • the short circuit rings 33 play no role.
  • the short circuit rings enter the air gap between the pole plate 16 and yoke 17, they increase the electrical damping.
  • the upper short circuit ring can be part of the structure of the PCB.
  • the short circuit rings are not electrically connected to the voice coil.
  • the short circuit rings are low weight electrically conducting material, such as aluminium.
  • Figure 5 shows two voice coils - an inner coil 29a and an outer coil 29b suspended by the flexible circuit board 40.
  • the short circuit rings 33 are also shown.
  • the suspension members have a lateral widening 60 which includes an opening. This shape increases the flexibility of the suspension members 46. There may be multiple widenings on each suspension member in series.
  • FIGS 7 and 8 show further variations more schematically.
  • the suspension members 46 are curved instead of straight.
  • the length of the suspension members 46 is increased by coupling each corner of the inner diaphragm portion 44 not to the closest corner of the outer frame, but to the next corner (clockwise in this example) around the outer frame.
  • the invention has been described with reference to a speaker, but it may be applied more generally to electro acoustic transducers, including microphones.
  • the PCB can be single sided or double sided. Solder bonds can be used for the mechanical and electrical connection, but additional mechanical coupling can also be used (such as fixings or adhesives).
  • the PCB can be of known design, with flexible conductive tracks such as copper on a flexible carrier.

Abstract

An electroacoustic transducer (speaker or microphone) has a coil attached to a diaphragm and a permanent magnet arrangement. The diaphragm comprises a flexible circuit board, wherein electrical and mechanical connection is made between the flexible circuit board and the coil. This provides a simple mechanical and electrical connection for the coil with low component count and cost and with good reliability.

Description

ELECTROACOUSTIC TRANSDUCER
The invention relates to an electro-acoustic transducer comprising a membrane and a magnet system.
In particular, the invention relates to the construction of micro speakers.
Micro speakers are loudspeakers mainly used in mobile applications such as mobile phones, mp3 players, navigation systems, laptops etc.
The key to the success of micro speakers is high performance and high reliability at a very low total cost level.
One difficulty in the miniaturisation and cost reduction results from the electrical connection that needs to be made to a moving component (the voice coil). Typically the connection is made with loop wires. The voice coil is glued to the membrane. The loop wires at the ends of the voice coils are formed and guided to the fixed part of the speaker, where they are soldered/thermo bonded to contact springs.
The loop wires are formed from the same material as the voice coil and move during the operation of the speaker. These moving loop wires are a critical aspect of the reliability of the speaker. This loop wire arrangement also requires a number of components dedicated specifically to the electrical connection.
According to the invention, there is provided an electro-acoustic transducer comprising a diaphragm, a coil attached to the diaphragm and a permanent magnet arrangement, wherein the magnetic field of the permanent magnet arrangement interacts with the coil electromagnetic field,
wherein the diaphragm comprises a flexible circuit board, wherein electrical and mechanical connection is made between the flexible circuit board and the coil.
In this arrangement, a flexible circuit board enables the diaphragm movement, and also enables fixed electrical connections to be made to the coil.
The flexible circuit board preferably comprises a flexible foil printed circuit board. The flexible circuit board can comprise an outer frame, an inner diaphragm part and suspension members extending between the outer frame and the inner diaphragm part. The suspension members thus provide the physical flexibility as well as providing conductor tracks to the outer frame. The electrical connection off the flexible board can then be at the static outer frame part of the board.
The inner diaphragm part can be a solid shape. This means the flexible board itself is providing the mechanical diaphragm. In another arrangement, the inner diaphragm part has a central opening over which is provided a plate. The plate then functions as the mechanical diaphragm.
There can be four suspension members extending between the corners of a generally rectangular inner diaphragm part and corners of a larger generally rectangular outer frame.
The coil is preferably annular and positioned at the edge of the inner diaphragm part.
In a preferred arrangement, there are two concentric annular coils, adjacent each other, and both positioned at the edge of the inner diaphragm part. The invention will now be described with reference to the accompanying drawings, in which:
Figure 1 shows, in cross-section, a known electroacoustic transducer; Figure 2 shows a first example of voice coil suspension arrangement for use in a transducer of the invention;
Figure 3 shows a second example of voice coil suspension arrangement for use in a transducer of the invention;
Figure 4 shows the arrangement of components in cross section;
Figure 5 shows a dual voice coil arrangement;
Figure 6 shows a third example of voice coil suspension arrangement for use in a transducer of the invention;
Figure 7 shows a fourth example of voice coil suspension arrangement for use in a transducer of the invention; and Figure 8 shows a fifth example of voice coil suspension arrangement for use in a transducer of the invention.
The invention provides an electroacoustic transducer (speaker or microphone) having a coil attached to a diaphragm and a permanent magnet arrangement. The diaphragm comprises a flexible circuit board, wherein electrical and mechanical connection is made between the flexible circuit board and the coil. This provides a simple mechanical and electrical connection for the coil with low component count and cost and with good reliability.
Figure 1 shows a known electroacoustic transducer 1 as described in
WO2004/014104, which in this case is a loudspeaker 1 . The transducer 1 is essentially centrally symmetrical in design, and has a transducer axis 2.
The transducer 1 has a pot-shaped housing 3, which is made of metal and which has a base wall 4 and a side wall 5. The base wall 4 is provided with a circular elevation 6, in which sound transmission openings are provided (not shown). Four strip-shaped lugs 7, running in radial directions in relation to transducer axis 2, protrude from the side wall 5. The lugs 7 are used to secure the components of the transducer 1 in the housing 3.
In the area of transducer axis 2, the pot- shaped housing 3 can have a height of 1 -5mm and the diameter of housing 3 in the direction running perpendicular to the direction of transducer axis 2 is for example in the range 5- 20mm. The transducer 1 is for example provided for use in a mobile telephone or in similar small scale telecommunications apparatus.
The transducer 1 contains a membrane 8, which is essentially U-shaped in its peripheral area 9. The U-shaped peripheral area 9 is connected to a ring 10, which is connected to the membrane 8 when the membrane 8 is produced. The ring 10 is for transport purposes and also for assembly purposes. When the transducer 1 is produced, the ring 10, including the membrane 8 which is connected to it, is inserted into the housing 3 in parallel with the direction of transducer axis 2, before the lugs 7 have been bent over. The outer part of the membrane is fixed in position. The membrane 8 has an intermediate area 1 1 adjacent to the U-shaped peripheral area 9, and an annular securing area 12 adjacent to intermediate area 1 1 . A central area 13 is located within the securing area 12, and the central area 13 is for sound generation. The membrane 8 as a whole is arranged parallel to transducer axis 2 so as to be oscillatory.
The transducer 1 is further equipped with a magnet system 14. The magnet system 14 comprises a permanent magnet 15 and an annular first yoke 16, which yoke 16 is located tight against the permanent magnet 15. A second yoke 17 has an L-shaped cross-sectional shape, and a disk-shaped first section 18 of the second yoke 17 is also located tight against the permanent magnet 15. An annular second section 19 protrudes from first section 18 parallel with transducer axis 2.
When the transducer 1 is produced, the first yoke 16, then the permanent magnet 15 and then the second yoke 17 are inserted into the housing 3 parallel with the direction of transducer axis 2. Once the three components 16, 15 and 17 of the magnet system have been inserted, the lugs 7 of housing 3 are bent over into their positions as shown in Figure 1 , as a result of which the membrane 8 and the magnet system 14 are fixed.
An air gap 20 is formed between the free end of second section 19 of the second yoke 17 and the inner edge of the first yoke 16, which air gap 20 is bounded by the two components of the magnet system, namely the first yoke 16 and the second yoke 17. The magnet system 14 encloses an inner space 22. Fixed in the inner space 22 is a contact carrier 24 made of plastic and provided to hold two moving-coil contacts 25, only one of which moving-coil contacts 25 is visible in Figure 1 owing to the sectional view.
The moving-coil contacts 25 are connected to the contact carrier 24 by means of extrusion.
The transducer 1 contains a moving coil 29 (the voice coil), which is partly arranged in air gap 20 and is connected to the membrane 8 in its securing area 12 using an adhesive connection. The moving coil 29 interacts with the magnet system 14, wherein an electrical signal representing a signal to be reproduced acoustically is sent to the moving coil 29, as a result of which the moving coil 29 is caused to oscillate, which results in the membrane 8 bringing about the signal to be reproduced acoustically.
The electrical signal sent to moving coil 29 must be amplified and, if applicable, its signal waveform must be influenced, before being sent to the moving coil 29. An integrated circuit 31 for this purpose is indicated schematically in Figure 1 .
The invention relates particularly to the way the voice coil 29 is mounted and electrically connected.
The invention can be applied to a microphone similar in design to that shown in Figure 1 , but it can be applied to other designs. Figure 1 is provided simply to show an example of the typical arrangement of components.
The relevant aspects of the design of Figure 1 are that there is a voice coil attached to a diaphragm, and a permanent magnet arrangement. The magnetic field of the permanent magnet arrangement interacts with the voice coil electromagnetic field.
The invention provides a transducer in which the diaphragm comprises a flexible circuit board, wherein electrical and mechanical connection is made between the flexible circuit board and the voice coil.
Figure 2 shows a first design from the underside. The flexible circuit board 40 preferably comprises a flexible foil printed circuit board.
The flexible circuit board comprises an outer frame 42, an inner diaphragm part 44 and suspension members 46 extending between the outer frame and the inner diaphragm part. The suspension members 46 thus provide the physical flexibility as well as providing conductor tracks to the outer frame. The corners of the outer frame can be provided with electrical contacts to the control circuitry, and the flexible circuit board 40 provides the electrical connections to the voice coil 29. The outer frame is fixed as in the example of Figure 1 .
The electrical connection off the flexible board is thus at the static outer frame part of the board.
The inner diaphragm part can be a solid shape, as shown in Figure 2. This means the flexible board itself is providing the mechanical diaphragm. In another arrangement shown in Figure 3, the inner diaphragm part 44 has a central opening 50 over which is provided a plate. The plate then functions as the mechanical diaphragm. In Figure 3, electrical connections from the voice coil 29 to the circuit board are at connection points 52 which are positioned within the shape of the voice coil.
In the examples shown, there are four suspension members extending between the corners of a generally rectangular inner diaphragm part 44 and corners of a larger generally rectangular outer frame 42. However, a different shape can be used.
The voice coil 29 is annular and positioned around the edge of the inner diaphragm part 44. There may be two concentric annular voice coils, adjacent each other, and both positioned around the edge of the inner diaphragm part. Dual voice coil speakers are known. The use of dual voice coils enables different amplification systems to be used, for example boost bridge amplifiers. The additional connections required to two voice coils has been a problem in the past.
The simple connection to the flexible PCB, with the PCB functioning as physical carrier as well as system for routing electrical signals, makes the implementation of a dual voice coil system very simple. The two voice coils are driven with signals that are phase inverted with respect to each other.
Figure 4 shows the arrangement of components in cross section.
In this example, the voice coil 29 is provided with short circuit rings 33. The voice coil is surrounded by the permanent magnet 15, the first yoke 16 which functions as a pole plate, and the second yoke 17. In the rest position (shown) or with low excursion of the voice coil, the short circuit rings 33 play no role. When the short circuit rings enter the air gap between the pole plate 16 and yoke 17, they increase the electrical damping. There may be only a lower short circuit ring, only an upper short circuit ring, or both as shown. The upper short circuit ring can be part of the structure of the PCB. The short circuit rings are not electrically connected to the voice coil. The short circuit rings are low weight electrically conducting material, such as aluminium. Figure 5 shows two voice coils - an inner coil 29a and an outer coil 29b suspended by the flexible circuit board 40. The short circuit rings 33 are also shown.
The specific design of the suspension arms may vary to obtain the desired flexibility and elasticity. Some variations are shown in Figures 5 to 7.
In Figure 6, the suspension members have a lateral widening 60 which includes an opening. This shape increases the flexibility of the suspension members 46. There may be multiple widenings on each suspension member in series.
Figures 7 and 8 show further variations more schematically.
In Figure 7, the suspension members 46 are curved instead of straight. In Figure 8, the length of the suspension members 46 is increased by coupling each corner of the inner diaphragm portion 44 not to the closest corner of the outer frame, but to the next corner (clockwise in this example) around the outer frame.
The invention has been described with reference to a speaker, but it may be applied more generally to electro acoustic transducers, including microphones.
The PCB can be single sided or double sided. Solder bonds can be used for the mechanical and electrical connection, but additional mechanical coupling can also be used (such as fixings or adhesives). The PCB can be of known design, with flexible conductive tracks such as copper on a flexible carrier.
Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1 . An electroacoustic transducer comprising a diaphragm (40), a coil (29) attached to the diaphragm and a permanent magnet arrangement (15,16,17), wherein the magnetic field of the permanent magnet arrangement (15,16,17) interacts with the coil (29) electromagnetic field,
wherein the diaphragm (40) comprises a flexible circuit board, wherein electrical and mechanical connection is made between the flexible circuit board (40) and the coil (29).
2. An electroacoustic transducer as claimed in claim 1 , wherein the flexible circuit board comprises a flexible foil printed circuit board.
3. An electroacoustic transducer as claimed in any preceding claim, wherein the flexible circuit board comprises an outer frame (42), an inner diaphragm part (44) and suspension members (46) extending between the outer frame (42) and the inner diaphragm part (44).
4. An electroacoustic transducer as claimed in claim 3, wherein the inner diaphragm part (44) is a solid shape.
5. An electroacoustic transducer as claimed in claim 3, wherein the inner diaphragm part (44) has a central opening (50) over which is provided a plate.
6. An electroacoustic transducer as claimed in claim 3, 4 or 5 comprising four suspension members (46) extending between the corners of a generally rectangular inner diaphragm part (44) and corners of a larger generally rectangular outer frame (42).
7. An electroacoustic transducer as claimed in any preceding claim, wherein the coil (29) is annular and positioned around the edge of the inner diaphragm part (44).
8. An electroacoustic transducer as claimed in claim 7, comprising two concentric annular coils (29a,29b), adjacent each other, and both positioned around the edge of the inner diaphragm part (44).
9. An electroacoustic transducer as claimed in any preceding claim comprising a speaker, and the or each coil (29,29a,29b) comprises a voice coil.
PCT/EP2011/074123 2011-01-04 2011-12-28 Electroacoustic transducer WO2012093058A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP11150121.9 2011-01-04
EP11150121A EP2472905A1 (en) 2011-01-04 2011-01-04 Electroacoustic transducer

Publications (1)

Publication Number Publication Date
WO2012093058A1 true WO2012093058A1 (en) 2012-07-12

Family

ID=44064927

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2011/074123 WO2012093058A1 (en) 2011-01-04 2011-12-28 Electroacoustic transducer

Country Status (2)

Country Link
EP (1) EP2472905A1 (en)
WO (1) WO2012093058A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9271084B2 (en) 2013-07-30 2016-02-23 Apple Inc. Suspension system for micro-speakers
US9288582B2 (en) 2013-07-30 2016-03-15 Apple Inc. Suspension system for micro-speakers
KR20180095877A (en) * 2017-01-04 2018-08-28 애플 인크. Capacitive sensing of movable coil structure with inset plate
US10194248B2 (en) 2016-02-19 2019-01-29 Apple Inc. Speaker with flex circuit acoustic radiator
US10321235B2 (en) 2016-09-23 2019-06-11 Apple Inc. Transducer having a conductive suspension member
US20200045432A1 (en) * 2018-08-01 2020-02-06 AAC Technologies Pte. Ltd. Speaker
WO2020103577A1 (en) * 2018-11-23 2020-05-28 歌尔股份有限公司 Loudspeaker
WO2020140173A1 (en) * 2018-12-30 2020-07-09 瑞声声学科技(深圳)有限公司 Loudspeaker

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103024638B (en) 2012-11-25 2015-09-30 歌尔声学股份有限公司 Electroacoustic transducer
US9838794B2 (en) 2013-04-26 2017-12-05 Sound Solutions International Co., Ltd. Double coil speaker
KR101564896B1 (en) * 2015-01-17 2015-10-30 주식회사 슬리비스 Diaphragm Assembly
CN104822111B (en) 2015-03-31 2018-10-12 歌尔股份有限公司 A kind of loud speaker module
CN208638712U (en) * 2018-08-13 2019-03-22 瑞声科技(新加坡)有限公司 Loudspeaker
WO2020140176A1 (en) * 2018-12-30 2020-07-09 瑞声声学科技(深圳)有限公司 Speaker
WO2020140177A1 (en) * 2018-12-30 2020-07-09 瑞声声学科技(深圳)有限公司 Speaker
FR3140726A1 (en) * 2022-10-10 2024-04-12 Devialet Membrane loudspeaker and associated production method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6066600A (en) * 1983-09-22 1985-04-16 Matsushita Electric Ind Co Ltd Composite type plane speaker
WO2004014104A2 (en) 2002-07-31 2004-02-12 Koninklijke Philips Electronics N.V. Electroacoustic transducer with built in transducer circuit
US20040086149A1 (en) * 2002-07-25 2004-05-06 Leif Johannsen One-magnet rectangular transducer
JP2010258495A (en) * 2009-04-21 2010-11-11 Tooru Tamai Planar speaker

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6066600A (en) * 1983-09-22 1985-04-16 Matsushita Electric Ind Co Ltd Composite type plane speaker
US20040086149A1 (en) * 2002-07-25 2004-05-06 Leif Johannsen One-magnet rectangular transducer
WO2004014104A2 (en) 2002-07-31 2004-02-12 Koninklijke Philips Electronics N.V. Electroacoustic transducer with built in transducer circuit
JP2010258495A (en) * 2009-04-21 2010-11-11 Tooru Tamai Planar speaker

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9288582B2 (en) 2013-07-30 2016-03-15 Apple Inc. Suspension system for micro-speakers
US9271084B2 (en) 2013-07-30 2016-02-23 Apple Inc. Suspension system for micro-speakers
US10194248B2 (en) 2016-02-19 2019-01-29 Apple Inc. Speaker with flex circuit acoustic radiator
US10687146B2 (en) 2016-02-19 2020-06-16 Apple Inc. Speaker with flex circuit acoustic radiator
US10321235B2 (en) 2016-09-23 2019-06-11 Apple Inc. Transducer having a conductive suspension member
US10911874B2 (en) 2016-09-23 2021-02-02 Apple Inc. Transducer having a conductive suspension member
US10149078B2 (en) 2017-01-04 2018-12-04 Apple Inc. Capacitive sensing of a moving-coil structure with an inset plate
KR102043899B1 (en) * 2017-01-04 2019-12-02 애플 인크. Capacitive Sensing of Moving Coil Structures with Inset Plates
AU2017390082B2 (en) * 2017-01-04 2019-05-23 Apple Inc. Capacitive sensing of a moving-coil structure with an inset plate
KR20180095877A (en) * 2017-01-04 2018-08-28 애플 인크. Capacitive sensing of movable coil structure with inset plate
US20200045432A1 (en) * 2018-08-01 2020-02-06 AAC Technologies Pte. Ltd. Speaker
US10932044B2 (en) * 2018-08-01 2021-02-23 AAC Technologies Pte. Ltd. Speaker
WO2020103577A1 (en) * 2018-11-23 2020-05-28 歌尔股份有限公司 Loudspeaker
WO2020140173A1 (en) * 2018-12-30 2020-07-09 瑞声声学科技(深圳)有限公司 Loudspeaker

Also Published As

Publication number Publication date
EP2472905A1 (en) 2012-07-04

Similar Documents

Publication Publication Date Title
EP2472905A1 (en) Electroacoustic transducer
KR101042032B1 (en) Micro-speaker
US10820107B2 (en) Speaker
CN110418260B (en) Sound production monomer, sound production module and electronic terminal
US8774448B2 (en) Speaker with elastic plate coupled to diaphragm
KR200455084Y1 (en) Multifunction micro speaker
JP5102876B2 (en) PCB with embedded speaker assembly
JP5049883B2 (en) Speaker
CN108401215B (en) High-voltage waterproof micro loudspeaker with improved coil structure
CN110401907B (en) Hybrid actuator
KR20040081470A (en) Flexible diaphragm with integrated coil
JP2018512014A (en) Mobile frameless acoustic transducer with optional coil wire and lead support
KR20110002370A (en) Micro speaker with dual suspension
CN109362003B (en) Loudspeaker
CN110418251B (en) Sound production monomer, sound production module and electronic terminal
US8649549B2 (en) Speaker
KR101208243B1 (en) Slim type speaker and magnetic circuit for it
KR101096788B1 (en) Multi-function micro-speaker
JP4557495B2 (en) Electroacoustic transducer
JP2012119845A (en) Electromagnetic electric-acoustic transducer
KR20110027996A (en) Multi-function micro-speaker
CN112312285A (en) Voice coil, loudspeaker and portable electronic equipment
JP2008092560A (en) Electroacoustic transducer
CN115396761A (en) Sound production device and electronic equipment
CN111698619B (en) Double-sided sound production device and electronic equipment

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11813678

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11813678

Country of ref document: EP

Kind code of ref document: A1