JP2007221417A - Loudspeaker diaphragm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a loudspeaker diaphragm capable of constituting a thin loudspeaker in which a high limit frequency is expanded as to a speaker diaphragm for a thin loudspeaker to be used for various image/acoustic apparatuses. <P>SOLUTION: The loudspeaker diaphragm is constituted of an approximately plane diaphragm 501, a spiral planar voice coil 504 formed at least on one surface of the diaphragm 501 and a reinforcing wire 121, formed on the inner periphery of the planar voice coil 504 separately from the voice coil 504. Since the reinforcing wire 121 also is formed on the plane diaphragm 501, in addition to the voice coil 504, the loudspeaker diaphragm can contribute to the thinning of a speaker as a loudspeaker diaphragm of superior shape rigidity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a speaker diaphragm for a speaker used in various audiovisual equipment and the like.

  In recent years, with the spread of so-called high-vision and wide-vision televisions, television screens have become widespread. On the other hand, narrow and thin TV sets as a whole are desired because of the housing situation in Japan.

  A speaker unit for a television (hereinafter referred to as a speaker) is usually attached to both sides of a cathode ray tube, which is a cause of increasing the width of the television set.

  Therefore, a speaker having an elongated structure such as a rectangular shape or an elliptical shape has been conventionally used for television. In addition, as the cathode ray tube becomes longer, it is required that the width of the speaker be made narrower. At the same time, there is a demand for higher sound quality corresponding to higher image quality on the screen.

  In addition, flat panel televisions using plasma displays and liquid crystal displays are increasing from cathode ray tubes, and there is a further demand for thinner speakers.

  Here, a conventional elongated speaker will be described with reference to FIGS. FIG. 14 shows a plan view of the speaker, and FIG. 15 shows a cross-sectional view in the short side direction.

  According to the figure, reference numeral 501 denotes a rectangular flat diaphragm, 502 a frame, 503 an edge that supports the diaphragm so as to vibrate, and 504 a voice coil that generates a driving force.

  The voice coil 504 is a so-called printed coil formed with a conductor pattern on the front and back surfaces of the diaphragm 501 using a polymer film as a base material, and is formed in a substantially rectangular shape.

  A magnetic circuit 508 including a magnet 506 and a yoke 507 is disposed below the diaphragm 501, and a magnetic flux generated in a magnetic gap 509 between the diaphragm 501 and the magnetic circuit 508 and a drive current applied to the voice coil 504. A driving force is further generated, and the diaphragm 501 is vibrated to generate sound.

As this type of speaker using a substantially rectangular diaphragm, for example, Patent Document 1 is known.
JP 58-47399 A

  However, there is a strong demand for further thinning of the above-mentioned speaker from the mounted device side.

  However, if the diaphragm made of a resin film is designed to be thin in order to reduce the thickness of the speaker, the shape rigidity of the diaphragm will decrease, and the high frequency limit frequency of the speaker will decrease. Since the center of the diaphragm needs to be dome-shaped or reinforced with a voice coil bobbin or the like, the height of the center of the diaphragm is increased, and there is a limit to making the speaker thinner in the conventional diaphragm structure. .

  An object of the present invention is to solve the above-mentioned problems and to provide an excellent speaker capable of increasing the high-frequency limit frequency and reducing the thickness.

  In order to solve the above problems, a speaker diaphragm of the present invention includes a substantially planar diaphragm, a spiral planar voice coil formed on at least one surface of the diaphragm, Reinforcing parts are formed inside and / or outside the outer periphery, and the reinforcing part is provided on the flat diaphragm in addition to the voice coil. As a plate, it can contribute to thinning of the speaker.

  As described above, the diaphragm for a speaker according to the present invention is provided with a planar coil and a reinforcing portion on a diaphragm that is an insulating substrate. With this configuration, the diaphragm does not have a dome shape at the center. Improves the shape rigidity of the plate, improves the vibration transmission from the voice coil to the diaphragm, extends the high frequency limit frequency and maintains the sound quality, making the diaphragm thinner, making the speaker thinner Can be realized.

  Hereinafter, an embodiment of a speaker diaphragm of the present invention will be described with reference to FIGS. In the description, the same parts as those of the speaker described in the prior art are denoted by the same reference numerals.

(Embodiment 1)
FIG. 1 is a plan view of a speaker according to an embodiment using the speaker diaphragm of the present invention, and FIG. 2 is a cross-sectional view in the short side direction. Claims 2, 3 and 4 will be described.

  According to the figure, reference numeral 501 denotes a substantially planar and rectangular diaphragm made of an insulating thin plate such as polyimide or epoxy. Reference numeral 502 denotes a frame, and reference numeral 503 denotes an edge that supports the diaphragm 501 so as to vibrate.

  The diaphragm 501 and the edge 503 are bonded with an adhesive 505. Reference numeral 504 denotes a voice coil that generates a driving force. The voice coil 504 is configured by printed wiring. The voice coil 504 is configured on both surfaces of the diaphragm 501, and includes an upper surface side coil 521 on the upper surface side of the diaphragm 501 and a lower surface side coil 522 on the lower surface side of the diaphragm 501.

  Reference numeral 510 denotes an upper surface lead line, which reaches a through hole 512 that connects the upper surface and the lower surface via an upper surface side coil 521 formed on the upper surface of the diaphragm 501. Further, it is connected to the lower surface side coil 522 through the through hole 512.

  The lower surface side coil 522 is wired on the lower surface of the diaphragm 501, and the end thereof is guided to the lower surface side lead wire 511. Although not shown, the lower surface side lead line 511 and the upper surface lead line 510 are connected to an audio signal output terminal of an external device.

  On the inner diameter side of the voice coil 504 and on at least one surface of the diaphragm 501, a reinforcing wiring 121 is formed by a printed wiring method. The reinforcing wiring 121 is configured such that it does not contact the voice coil 504 in the direction substantially parallel to the short side of the diaphragm 501 on the inner periphery of the coil 521 wired in the diaphragm long side direction.

  Note that the production efficiency can be improved by forming the voice coil 504 and the reinforcing wiring 121 in the same manufacturing process.

  A magnetic circuit 508 including a magnet 506 and a yoke 507 is disposed below the diaphragm 501, and a magnetic flux generated in a magnetic gap 509 between the diaphragm 501 and the magnetic circuit 508 is applied to the voice coil 504. A driving force is generated from the driving current and the diaphragm 501 is vibrated to generate sound.

  The speaker configured as described above has many resonance modes in the audible band because the diaphragm 501 has a substantially planar structure. Resonance modes can be broadly classified into those that occur in the long side direction and those that occur in the short side direction. In the long side direction, resonance is generated at a low frequency because the length of the diaphragm is long.

  Since the voice coil 504 is arranged so as to be driven entirely in the long side direction of the diaphragm 501, resonance occurring in the long side direction of the diaphragm 501 is suppressed. On the other hand, the resonance generated in the short side direction has a higher frequency than the long side direction because the distance of the diaphragm 501 is short.

  In order to improve the performance as a speaker, it is important to increase the resonance frequency in the short side direction. For this purpose, it is necessary to increase the rigidity of the diaphragm.

  In the present embodiment, the reinforcing wiring 121 disposed on the inner peripheral portion of the planar voice coil 504 of the diaphragm 501 is approximately in the long side direction of the plurality of diaphragms in the direction extending in the short side direction of the diaphragm 501. It is arranged in parallel and is made of a lightweight and highly rigid material such as copper or aluminum.

When the diaphragm is made of a polyimide material, the Young's modulus is about 4 × 10 ⁹ , and the Young's modulus of copper is 13.0 × 10 ^{10, which} is one digit higher. For this reason, the reinforcing wiring 121 works in a direction to increase the rigidity of the diaphragm 501 in the short side direction, and the resonance frequency in the short side direction becomes high. Therefore, the reproduction band of the speaker can be expanded and a low distortion speaker can be provided.

  In the present embodiment, the diaphragm 501 and the edge 503 are described as having separate structures. However, the diaphragm 501 and the edge 503 may be integrated with the same material, and the same applies to the following embodiments.

  In the above-described embodiment, the planar voice coil 504 and the reinforcing wiring 121 are described as being formed on the diaphragm 501. However, the planar voice coil 504 and the reinforcing wiring 121 are formed on a plastic film sheet such as a polyimide material. It can also be formed by pasting.

(Embodiment 2)
FIG. 3 is a plan view of a speaker showing another embodiment of the speaker diaphragm of the present invention, and FIG. 4 is a cross-sectional view in the short-side direction.

  According to the figure, reference numeral 501 denotes a substantially rectangular flat plate vibration plate made of a thin plate such as polyimide or epoxy, 502 is a frame, and 503 is an edge that supports the vibration plate 501 so as to vibrate. The diaphragm 501 and the edge 503 are bonded with an adhesive 505.

  Reference numeral 504 denotes a voice coil that generates a driving force. The voice coil 504 is configured on both surfaces of the diaphragm 501 and is formed of an upper surface side coil 521 and a lower surface side coil 522. The wiring between the upper surface side coil 521 and the lower surface side coil 522 extends from the end of the upper surface side coil 521 to the through hole 512 and is connected to the end of the lower surface side coil via the through hole 512.

  The other terminal of the upper surface coil 521 forms an upper surface lead wire 510, and the other terminal of the lower surface side coil 522 forms a lower surface lead wire 511. The upper surface lead wire 510 and the lower surface lead wire 511 are voice coils. Both terminals 504 will be formed.

  A plurality of reinforcing wires 201 are arranged in a line extending in the short side direction of the diaphragm and substantially parallel to the long side direction. The upper surface reinforcing wiring 202 is formed on the upper surface side with the diaphragm 501 as the center, and the lower surface reinforcing wiring 203 is configured symmetrically with the diaphragm 501 sandwiched on the lower surface side.

  The end portion 202a of the upper surface reinforcing wire 202 and the end portion 203a of the lower surface reinforcing wire 203 of the reinforcing wiring 201 are alternately connected to the inner peripheral portions of the upper surface voice coil 521 and the lower surface voice coil 522, respectively. 203a is alternately connected to the left and right of the long side portions of the upper voice coil 521 and the lower voice coil 522.

  In the present embodiment, since the reinforcing wiring 201 forms a sandwich structure using the diaphragm 501 as a core material, there is an effect that the rigidity is further increased. Further, since the voice coil 504 is alternately connected in the long side direction and is also alternately connected to the upper and lower sides sandwiching the diaphragm 501, the short side direction is achieved without shorting the coil. Since the length of the reinforcing wiring 201 can be maximized, the reinforcing effect can be maximized.

  FIG. 5 is a sound pressure frequency characteristic diagram of the speaker according to the present embodiment by the finite element method. The shape of the speaker diaphragm 501 is 11 mm in width and 63 mm in length, and a substantially roll-shaped edge 503 is formed on the outer periphery of the diaphragm 501. A polymer material having a diaphragm thickness of 40 microns is used, and the inner periphery of the voice coil 504 is used. It was assumed that the reinforcing wires were formed at intervals of 3 mm in the short side direction with a width of 0.1 mm.

  In FIG. 5, the dotted line is the sound pressure frequency characteristic of the speaker when there is no reinforcing wiring and the solid line is when there is reinforcing wiring. It was estimated that the reproduction frequency was increased from 10 kHz to 17 kHz by the reinforcing wiring.

  In the first and second embodiments described above, the diaphragm 501 and the voice coil 504 have a rectangular shape, but the diaphragm and the coil have different lengths in the vertical and horizontal directions. The shape is not limited and the lengths in the vertical direction and the horizontal direction may be the same.

  Even in the case of a diaphragm having the same length in the vertical direction and the horizontal direction, the rigidity can be increased by forming a reinforcing layer (wiring) at the center.

  In addition, the shape of the diaphragm and the coil may be an ellipse or the like. Further, the voice coil 504 may be a flat coil in which a covered wire is wound in a flat shape instead of a printed wiring.

(Embodiment 3)
FIG. 6 is a plan view showing a loudspeaker according to another embodiment, and mainly describes claim 6.

  The difference from the first embodiment is that reinforcing wirings 301 are formed in a lattice shape in a direction extending along the long side direction and the short side direction of diaphragm 501. With this configuration, the rigidity of the diaphragm 501 in the long side direction and the short side direction is improved.

(Embodiment 4)
FIG. 7 is also a plan view showing a speaker according to another embodiment, which mainly describes claims 7 and 8.

  The difference from the speaker of the first embodiment is that a plurality of reinforcing wirings 401 are provided in a long side direction with a predetermined inclination, and FIG. 8 is an example of the development, and the speaker of FIG. The difference is that the reinforcing wirings 401 and 402 on the front and back sides of the diaphragm 501 are oppositely inclined on the front and back of the diaphragm 501, and an “X” -shaped reinforcing portion composed of the reinforcing wirings 401 and 402 is viewed from above. Are arranged in the long side direction, and the effect of increasing the rigidity in both the long side direction and the short side direction at the inner peripheral portion of the coil portion 504 is exhibited.

(Embodiment 5)
9 and 10 also illustrate a speaker using a speaker diaphragm according to another embodiment different from the other embodiments described above. FIG. 9 is a plan view, and FIG. A sectional view in the side direction is shown, and mainly Claim 1 will be described.

  Only differences from the first embodiment will be described with reference to FIG. 1. Reference numeral 701 denotes reinforcing wiring formed on the outer periphery of the lower surface side coil 522 provided on the back side of the voice coil 504, and the strength of the outer peripheral portion of the diaphragm 501. This improves the flatness of the sound pressure frequency characteristic by working to suppress abnormal vibration amplitude at the outer periphery of the diaphragm due to edge resonance. The reinforcing wiring 121 provided in the first embodiment is deleted.

(Embodiment 6)
FIG. 11 is also a plan view of a speaker according to another embodiment of the present invention. FIG. 12 is a cross-sectional view in the short side direction, and mainly describes claim 1. The difference from the first embodiment is that the reinforcing wiring 701 of the fifth embodiment is formed in addition to the reinforcing wiring 121 of the first embodiment.

  As described above, since the reinforcing wirings 121 and 701 are provided on the inner and outer circumferences of the voice coil 504, the high-frequency reproduction limit frequency can be improved and the flatness of the frequency characteristics can be improved.

(Embodiment 7)
FIG. 13 is also a plan view of a speaker according to another embodiment of the present invention. Only the differences from the first embodiment will be described with reference to the same drawing. The upper surface lead wire 510 is drawn out from one end portion in the short side direction of the diaphragm 501, and the user terminal 971 of the frame on the other end portion side by the lead wire portion 952. The lower-side lead wire 511 is pulled out from one end portion in the short side direction of the diaphragm 501 on the side opposite to the upper lead wire 510, and is connected to the user terminal 972 of the frame on the other end side through the lead portion 962. It is a connected point.

  In this embodiment, the length of the lead wire portion 952 from the lead wire 510 to the user terminal 971 is configured to be maximum, so that the stiffness of the lead wire portion can be reduced.

  The lead wire 511 and the user terminal 972 have the same relationship via the lead wire portion 962.

  Therefore, an increase in the minimum resonance frequency of the speaker can be suppressed, and connection to the user terminal can be performed without adhering a lead wire to the planar coil, thereby reducing the number of components and the number of assembly steps. .

  The speaker diaphragm according to the present invention improves the shape rigidity of the diaphragm without making the center of the diaphragm a dome shape, improves the vibration transmission from the voice coil to the diaphragm, and increases the high frequency limit frequency. The diaphragm can be made thin while extending and maintaining the sound quality, and the speaker can be made thinner, so the shape stability of the diaphragm, better speaker characteristics, lower distortion, and lower price It can also be applied to applications such as loudspeaker diaphragms and speakers used in various audio equipments that need to be miniaturized, as well as various electronic devices and various devices. The present invention can be applied to electronic devices such as game machines, and further to devices such as automobiles.

The top view of the speaker in one Embodiment using the diaphragm for speakers of this invention Sectional view in the short side direction Top view of speaker using speaker diaphragm of other embodiment Cross section in the same short side direction Sound pressure frequency characteristic diagram of the speaker according to the present embodiment by the finite element method The top view of the speaker in other embodiment of the diaphragm for speakers of the present invention. The top view of the speaker using the diaphragm for speakers of other different embodiments Top view of the speaker in the same example The top view of the speaker using the diaphragm for speakers of other embodiments different from the other embodiments Cross-sectional view in the short side direction The top view of the speaker using the diaphragm for speakers of other embodiments of the present invention. Sectional view in the short side direction The top view of the speaker using the diaphragm for speakers of other embodiments of the present invention. Plan view of a conventional slim speaker Sectional view in the short side direction

Explanation of symbols

121 Reinforcing wiring 501 Diaphragm 502 Frame 503 Edge 504 Voice coil 505 Adhesive 506 Magnet 507 Yoke 508 Magnetic circuit 509 Magnetic gap 510,511 Lead wire 512 Through hole 521 Upper coil 522 Lower coil

Claims (8)

A substantially planar diaphragm, a spiral planar voice coil formed on at least one surface of the diaphragm, and a reinforcing portion spaced apart from these inside and / or outside the outer periphery of the planar voice coil The formed speaker diaphragm. The speaker diaphragm according to claim 1, wherein the planar voice coil and the reinforcing portion are formed on the same insulating thin plate, and the insulating thin plate is attached to the diaphragm. The speaker diaphragm according to claim 1, wherein the planar voice coil and the reinforcing portion are formed of the same material on the same surface of the diaphragm. The speaker diaphragm according to claim 1, wherein the diaphragm has an elongated shape, the planar voice coil has a corresponding elongated shape, and a reinforcing portion is formed at least in the inner circumference, and is separated from the inner circumference of the planar voice coil. A speaker diaphragm in which a plurality of reinforcing portions provided in parallel are provided substantially in parallel in the major axis direction. The speaker diaphragm according to claim 1, wherein the diaphragm has an elongated shape, a planar voice coil has a corresponding elongated shape, and a reinforcing portion is formed at least in an inner periphery, wherein the reinforcing portion is on the front and back of the diaphragm. A plurality of speaker diaphragms provided substantially parallel to each other in the major axis direction and alternately connected to the left and right of the long side portion of the voice coil. The speaker diaphragm according to claim 1, wherein the diaphragm has an elongated shape, the planar voice coil has a corresponding elongated shape, and a reinforcing portion is formed at least in the inner circumference, and is separated from the inner circumference of the planar voice coil. A speaker diaphragm in which reinforcing portions provided in a grid pattern are provided. The speaker diaphragm according to claim 1, wherein the diaphragm has an elongated shape, a planar voice coil has a corresponding elongated shape, and a reinforcing portion is formed at least in the inner periphery, and the reinforcing portion is provided with an inclination and substantially parallel. A plurality of speaker diaphragms provided in the long side direction. The speaker diaphragm according to claim 7, wherein a plurality of X-shaped reinforcing portions are provided in the long side direction as viewed from above by reinforcing wiring on the front and back of the speaker diaphragm.

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