Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R7/00—Diaphragms for electromechanical transducers; Cones
  • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
  • H04R7/12—Non-planar diaphragms or cones
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R7/00—Diaphragms for electromechanical transducers; Cones
  • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
  • H04R7/12—Non-planar diaphragms or cones
  • H04R7/122—Non-planar diaphragms or cones comprising a plurality of sections or layers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R7/00—Diaphragms for electromechanical transducers; Cones
  • H04R7/16—Mounting or tensioning of diaphragms or cones
  • H04R7/18—Mounting or tensioning of diaphragms or cones at the periphery
  • H04R7/20—Securing diaphragm or cone resiliently to support by flexible material, springs, cords, or strands
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
  • H04R9/02—Details
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
  • H04R31/003—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor for diaphragms or their outer suspension
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R7/00—Diaphragms for electromechanical transducers; Cones
  • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
  • H04R7/12—Non-planar diaphragms or cones
  • H04R7/127—Non-planar diaphragms or cones dome-shaped
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
  • H04R9/06—Loudspeakers

Definitions

• Loudspeaker having a composite diaphragm structure
• the invention relates to a loudspeaker provided with a chassis, a movable body, a resilient suspension for guiding the movable body with respect to the chassis along a translation axis, and an electric actuator for driving the movable body along the translation axis.
• Speakers of such a type are generally known; e.g. PCT Patent Application WO 96/14722 discloses such a loudspeaker.
• This known loudspeaker has a frame, a membrane and an electromagnetic driving unit.
• the membrane is formed by a conical body and has an outer circumferential edge and an inner circumferential edge.
• the driving unit is provided with a stationary part and a movable part.
• the stationary part includes a permanent magnet and a magnetic yoke and is secured to the frame.
• the movable part includes a voice coil and a cylindrical coil support.
• the membrane At its outer circumferential edge, the membrane is connected to the frame by means of a flexible suspension and, at its inner circumferential edge, it is adhered to the coil support, which in its turn is connected to the frame by means of a spider.
• the conical membrane of the known loudspeaker has a certain height in order to obtain sufficient stiffness.
• the membrane must have a certain minimal stiffness in order to be able to move like a piston, not only for low frequency reproduction but for the whole or at least the larger part of the audio spectrum. For this reason, there arise problems relating to the speaker's performance when a shallow speaker, i.e. a speaker having a small height, is required in certain applications.
• the loudspeaker according to the invention which is provided with a chassis, a movable body, a resilient suspension for guiding the movable body with respect to the chassis along a translation axis, and an electric actuator for driving the movable body along the translation axis, which movable body has a diaphragm structure comprising a centrally situated dome-shaped diaphragm and a decentralized cone-shaped diaphragm concentrically arranged with respect to the dome-shaped diaphragm, which cone- shaped diaphragm has a back portion and a front portion which is wider than the back portion, wherein both diaphragms are attached to each other near the back portion of the cone-shaped diaphragm, the cone-shaped diaphragm enveloping the dome-shaped diaphragm, and wherein the resilient
• the loudspeaker according to the invention has a diaphragm structure which is composed of an outwardly convex, particularly dome-shaped, diaphragm and a cone-shaped diaphragm situated around the other diaphragm.
• a diaphragm structure which is composed of an outwardly convex, particularly dome-shaped, diaphragm and a cone-shaped diaphragm situated around the other diaphragm.
• a cone-shaped diaphragm known per se may be used.
• a rigid dome-shaped diaphragm known per se may be used.
• Such diaphragms are known, for instance, from US-A 3,925,626.
• the loudspeaker according to the invention can be driven by a usual audio transformer of an amplifier system known per se.
• a favorable embodiment of the loudspeaker according to the invention has the characteristic feature that the electric actuator comprises a stationary part which is secured to the chassis or to a stationary element fixed to the chassis and further comprises a translatable part which is secured to the dome-shaped diaphragm. Due to this feature, the translatable part of the electric actuator extends into the space enveloped by the dome-shaped diaphragm.
• said US-A 3,925,626 discloses an all-frequency loudspeaker which has a domed diaphragm instead of the usual cone diaphragm of the prior art in order to get, inter alia, a high-fidelity sound.
• a form Secured to the underside of the diaphragm is a form which extends downwards into an air gap formed by a pole piece and a topring of a magnet system and on which a voice coil has been wound.
• the device formed by the diaphragm and the form is suspended from a framework by means of a resilient suspension secured to both the diaphragm and the framework and a resilient support secured to both the form and the framework.
• the loudspeaker according to the invention has no suspension means secured to the coil support, and thus does not have the above-described disadvantage.
• the back portion of the cone-shaped diaphragm includes an inner circumferential edge to which an outer circumferential rim of the dome-shaped diaphragm is connected, said edge and rim being preferably attached to each other by means of an adhesive, such as a glue.
• the stationary part includes a magnetic yoke with a permanent magnet and the translatable part includes a coil support with a voice coil, which coil extends in an air gap of the magnetic yoke and has a coil axis coinciding with the translation axis of the movable body.
• the loudspeaker according to the invention is suitable for sound reproduction in hifi, home, automotive, TV and multimedia systems and, as already indicated, is particularly suitable for applications having very small built-in depths.
• the invention also relates to a diaphragm structure intended for use in the loudspeaker according to the invention.
• the diaphragm structure according to the invention has the characterizing feature that it is composed of a central dome-shaped diaphragm and a cone-shaped diaphragm concentrically arranged with respect to the dome- shaped diaphragm.
• the invention further relates to a loudspeaker unit comprising the loudspeaker according to the invention and also comprising a housing accommodating the loudspeaker. It is noted in relation to the claims that various combinations of characteristic features defined in the claims are possible. The above-mentioned and other aspects of the invention are apparent from and will be elucidated, by way of non-limitative examples, with reference to the embodiment described hereinafter.
• Figure 1 shows an embodiment of the loudspeaker according to the invention in a diagrammic cross-section
• Figure 2 is a perspective elerational view of the loudspeaker of Fig.1 in an exploded view.
• the electrodynamic loudspeaker shown in the Figures, comprises a chassis 2, a movable body 4 and an electromagnetic actuator 6.
• the loudspeaker may be accommodated in a housing.
• the chassis 2 may be fixed in an appropriate opening in a wall of this housing.
• the housing is shown diagrammatically by means of a wall section 1 in broken lines.
• the movable body 4 has a three-dimensional diaphragm structure comprising a central dome-shaped diaphragm 8 and a cone-shaped diaphragm 10 concentrically arranged with respect to the dome-shaped diaphragm 8.
• the dome-shaped diaphragm 8 may be made of a metal, such as aluminium; reinforced plastics; pressed paper; or any other suitable material.
• the diaphragm 8 has a sufficient stiffness and may be provided with a central opening 8a covered by a dust cap 9 of any suitable material, such as paper, plastics, or textile.
• the cone-shaped diaphragm 10 may be made of pressed paper, carbon fiber, poly glass, aluminium, or any other suitable material.
• the cone-shaped diaphragm 10 has a back portion 10 b and a front portion 10 f which is wider than the back portion 10 b .
• the dome-shaped diaphragm 8 and the cone-shaped diaphragm 10 are mutually secured at the back portion 10 b .
• the cone-shaped diaphragm 10 has an inner circumferential edge 10 thread while the dome-shaped diaphragm 8 has a corresponding outer circumferential rim 8 0 .
• the edge 1 Oi and the rim 8 0 preferably have round cross-sections so that the edge 10, and the rim 8 0 fit each other.
• the edge 10, and the rim 8 0 are preferably glued to each other.
• the loudspeaker further comprises a resilient suspension for suspending the movable body 4 from the chassis 2 and for guiding the movable body along a translation axis T.
• the suspension includes a first resilient element 12a and a second resilient element 12b.
• the first resilient element 12a is a ring-like spider, an inner circumferential brim 12a, of which is attached to the edge 10, and/or the rim 8 0 and an outer circumferential brim 12ao is attached to the chassis 2.
• a glue may be used for both attachments.
• the spider 12a may be a known flexible corrugated body and ensures that the movable body 4 can perform well- defined translation movements with respect to the chassis 2.
• the second resilient element 12b has a roll structure known per se and is formed, for example, from a bent rubber or foam annular strip. On its outer circumference, the second element 12b is secured, for example glued, to the chassis 2 and on its inner circumference to an outer circumferential edge 10 o of the cone-shaped membrane 10.
• the actuator 6 essentially comprises two elements, namely a stationary actuator part 6a which is fixed to the chassis 2 and a translatable actuator part 6b which is connected to the movable body 4.
• One of the actuator parts - in this example the part 6a - is provided with a permanent magnet 13, in this example annular in shape and axially polarized, and the other actuator part - in this example the part 6b - is provided with a magnet coil 14.
• the permanent magnet 13 is formed from a neodymium-iron-boron alloy and forms a magnetic yoke 13a with soft iron portions of the stationary actuator part 6a, which yoke defines an air gap 16.
• a lead wire 17 connects the coil 14 by means of a connector 18 which is adhered to the chassis 2.
• both actuator parts 6a, 6b magnetically co-operate with each other over the air gap 16 for generating a driving force on the movable body 4 parallel to the translation axis T and thus on the dome-shaped diaphragm 8 and the cone-shaped diaphragm 10. It is to be noted that the invention is not limited to the embodiment shown.
• the dome-shaped diaphragm and the cone-shaped diaphragm may be formed as an integral combination, thus comprising or consisting of a single diaphragm structure.
• the loudspeaker unit may not only comprise one or more speakers but also one or more passive radiators or bass reflex ports.
• the loudspeaker according to the invention is not limited to a certain power.
• the dome- shaped diaphragm may be provided with perforations and/or a coating.
• the outer circumferential rim of the dome-shaped diaphragm does not need to be a back portion of the dome-shaped diaphragm, but may be a rim parallel to the back portion.

Landscapes

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

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34203252

Family Applications (1)

Country Status (6)

Cited By (5)

Families Citing this family (18)

Citations (4)

Family Cites Families (13)

• 2004
  • 2004-08-06 KR KR1020067003651A patent/KR101139126B1/ko not_active Expired - Fee Related
  • 2004-08-06 JP JP2006523728A patent/JP4675895B2/ja not_active Expired - Fee Related
  • 2004-08-06 EP EP04744755A patent/EP1658753B1/en not_active Expired - Lifetime
  • 2004-08-06 WO PCT/IB2004/051413 patent/WO2005020630A1/en not_active Ceased
  • 2004-08-06 US US10/568,647 patent/US7570780B2/en not_active Expired - Fee Related
  • 2004-08-06 CN CN2004800239356A patent/CN1839658B/zh not_active Expired - Fee Related

Patent Citations (4)

Non-Patent Citations (2)

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