JP2000350278A - Speaker and speaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend a low frequency sound pressure, to radiate a low sound frequency and to prevent a lightweight speaker box from moving by providing a flexible means that moves a magnetic circuit of a speaker main body reverse to a vibration system of the speaker so as to increase sound radiation in spite of provision of only one speaker. SOLUTION: Since a vibration system including a diaphragm 7 of the speaker A is separated with compliance via a flexible section 27 formed to a frame 5, an equivalent mass of a magnetic circuit positioned lower than the flexible section 27 causes other vibrations from that of the diaphragm 7. That is, a force F2 reverse to the sound radiation force F1 in a direction F1 is exerted to the vibration system of the speaker A by an inertia of going to stop the operation of the vibration system, and a reaction force F2 shown in an arrow F2 is exerted to the magnetic circuit. Since the reaction force -F1 with respect to the sound radiation force F1 of the diaphragm 7 and a reaction force -F2 with respect to the action force F2 exerted to the magnetic circuit positioned lower than the flexible part 27 are cancelled or attenuated with each other by making the force F1 nearly equal to the force F2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker and a speaker device suitable for use in a small speaker and a speaker built in a lightweight speaker box. The present invention relates to a speaker device configured to cancel or attenuate a reaction force of a radiation force.

[0002]

2. Description of the Related Art Conventionally, in order to suppress vibration of a baffle board of a speaker box in which a speaker is mounted, a vibrator or a vibrator that vibrates in a direction opposite to a vibration direction of a speaker vibrated by a diaphragm. A speaker device having a transducer is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-2120.
No. 00, JP-A-1-307398 and the like are known in detail.

The above-mentioned Japanese Patent Application Laid-Open No. Sho 62-212000 discloses a speaker device as shown in FIG. In FIG. 8, reference numeral 1 denotes a ring-shaped magnet, and reference numerals 2 and 3 denote a plate and a yoke which are attached so as to sandwich the magnet 1 and partially have a magnetic gap 4 formed therein. A frame 5 of the speaker A is mounted on the plate 2, and an edge 6 is provided on an outer peripheral portion of the diaphragm 7, and the outer periphery of the cone-shaped diaphragm 7 is formed by the edge 6.
Is held in.

On the other hand, a voice coil bobbin 8 is attached to the inner peripheral portion of the diaphragm 7, and the voice coil bobbin 8
Is wound with a voice coil 9, which is inserted into a magnetic gap 4 formed by the plate 2 and the yoke 3. The configurations indicated by the reference numerals 1 to 9 are the basic structure of the well-known electrodynamic speaker A.

One end of a screw 10 is screwed into the center of the rear surface of the yoke 3 of the speaker A, and the other end of the screw 10 has exactly the same structure as the magnet 1, plate 2 and yoke 3 of the speaker A described above. Magnet 1
1, a magnetic circuit comprising a plate 12 and a yoke 13 is mounted.

[0006] A frame 14 is mounted on the plate 12, and two dampers 15, 16 are mounted on the frame 14.
The drive coil bobbin 17 is held by 5 and 16.

[0007] A drive coil 18 is wound around one end of the drive coil bobbin 17, and the drive coil 18 is inserted into a magnetic gap 19 formed by the plate 12 and the yoke 13. A weight 20 is attached to the other end of the drive coil bobbin 17.
The vibration system including 0 is substantially equal to the equivalent mass of the vibration system including the cone-shaped diaphragm 7 in the speaker A. The configuration indicated by the reference numerals 11 to 20 indicates the electric / vibration transducer B.

In the above configuration, the speaker A and the electric
The vibration transducer B is mounted on a baffle board 22 of the speaker box 21. Now, the voice coil 9 by a known action if energizing electrical signal to the voice coil 9 of the speaker A is produced driving force F ₁ vibrates in the horizontal direction in the figure, the sound reproduction by driving the diaphragm 7 of the cone type Do.

At this time, when the same electric signal is applied to the drive coil 18 of the electric / vibration transducer B, the drive coil 18 also vibrates in the left-right direction in FIG.
₂ to drive the weight 20 in the same direction. Here, if the equivalent mass of the vibration system including the diaphragm 7 and the like in the speaker A and the vibration system including the weight 20 and the like in the electric / vibration transducer B are substantially equal, the reaction force −F _{1 received} by the speaker A by the vibration system is equal to the electric force. · a reaction force -F ₂ of the vibration system of the vibration transducer B are substantially equal.

Therefore, the reaction of the speaker A due to the driving of the diaphragm 7 is canceled by the electric / vibration transducer B, so that the vibration of the baffle board 22 of the speaker box 21 and the swing of the speaker box 21 are suppressed.

Further, in the above-mentioned Japanese Patent Application Laid-Open No. 1-307398, the reaction force -F ₁ generated by the acting force F ₁ of the diaphragm of the first speaker with the cone openings of the diaphragms of the two speakers facing in opposite directions. also discloses a speaker device for canceling the counteraction force -F ₂ acting force F ₂ of the diaphragm of the second speaker.

[0012]

In the above-described conventional speaker and speaker device, there is a demand to reduce the volume of the speaker box 21 to reduce the size and obtain an inexpensive speaker device. When the volume of the loudspeaker is reduced, the low-frequency reproduction limit is increased, so that the amplitude of the speaker is increased.

However, by increasing the amplitude of a small loudspeaker, the sound pressure in the loudspeaker box 21 increases, and peaks and valleys occur in the frequency characteristics. As a method for solving such a problem, a speaker and a speaker device which use a phase-inversion type speaker box to effectively utilize sound waves emitted from the back of the diaphragm to radiate a low frequency range without distortion are also widely used. Have been.

In order to incorporate the speaker shown in FIG. 8 into the above-mentioned small-sized phase-inversion type speaker box 21, a pair of speakers A and an electric vibration transducer B having substantially the same structure are used.
Alternatively, a pair of speakers must be arranged back to back as in Japanese Patent Application Laid-Open No. Hei 1-307398, so that the depth direction of the speaker box becomes large, making it difficult to reduce the size and increasing the cost.

An object of the present invention is to provide a speaker and a speaker device which have solved the above-mentioned problems. The problem to be solved by the present invention is to increase the sound radiation action of a small speaker by using one speaker. It is an object of the present invention to obtain a speaker and a speaker device which can increase the low-frequency sound pressure and radiate the low-frequency sound while preventing the swinging of a lightweight speaker box.

[0016]

A speaker device according to the present invention comprises a magnetic circuit or a flexible means for moving a speaker body in a direction opposite to a vibration system constituting the speaker.

The speaker device according to the present invention comprises a speaker having a magnetic circuit or movable means for moving a speaker body in a direction opposite to a vibration system constituting the speaker, which is disposed in a speaker box.

According to the loudspeaker and the loudspeaker device of the present invention, the size of the loudspeaker device is reduced and the electro-acoustic conversion efficiency is improved, and one speaker cancels out the reaction force of the sound radiation force of the diaphragm of the loudspeaker. It can be attenuated, and the depth between the baffle board and the back plate of the speaker box can be reduced to reduce the size.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a speaker device according to the present invention.
An embodiment will be described with reference to FIGS. Note that the same reference numerals are given to portions corresponding to the speaker device shown in FIG.

FIG. 1 is a side sectional view of a speaker showing one embodiment of this embodiment, and a speaker A is a small speaker as a whole. The yoke 3 is formed of a disc-shaped portion made of a plate material such as pure iron, a column-shaped center pole 3a erected at the center of the disc-shaped portion, and a disc-shaped portion concentric with the center pole 3a. A magnet guide 3b composed of a step is formed integrally.

A ring-shaped driving magnet 1 magnetized in the thickness direction of ferrite or the like is bonded on the disc-shaped portion of the yoke 3 via an adhesive. The inner diameter of the ring-shaped driving magnet 1 is fitted and positioned in a step portion of a magnet guide 3 b formed in a disk-shaped portion of the yoke 3.

The plate 2 is joined to the driving magnet 1. In this case, the gap guide should be center pole 3
a while keeping it inserted in a.
Is applied to the upper surface of the gap guide, and the inner diameter of the plate 2 is inserted into the outer diameter of the gap guide to be fixed by bonding. The plate 2 is made of a disc made of pure iron or the like, and is made of a punched plate material having a through hole formed in the center thereof. And a voice coil 8 are provided.

The frame 5 is pressed in a funnel shape with steel or the like. The frame 5 of this example is a funnel-shaped frame 5
The flexible portion 27 is formed between the bottom portion 5a and the inclined portion 5b. In FIG. 1, a flexible portion 27 is formed on the inclined portion 5b. The flexible portion 27 is configured to have a spring property by, for example, corrugating the waveform in the same manner as the damper 18 or the like so as to provide a predetermined compliance.

The metal part of the magnetic circuit is formed on the plate 2 by fixing the frame 5 formed as described above.

A voice coil 8 wound around a cylindrical voice coil bobbin 9 is inserted into the magnetic air gap 4 of the above-described magnetic circuit, and the voice coil bobbin is passed through a damper 18 having a corrugation of a waveform so as to be able to swing up and down. Hold 9

The inner diameter of the damper 18 is joined to the outer diameter of the voice coil bobbin 9 via an adhesive, and the outer diameter is joined to the outer periphery of the bottom surface of the frame 5. Further, the inner diameter of a funnel-shaped diaphragm 7 having a free or fixed edge 6 made of paper or the like is joined to the upper outer diameter portion of the voice coil bobbin 9, and the largest diameter portion of the diaphragm 7 is joined to the upper opening peripheral portion of the frame 5. Is fixed to the voice coil bobbin 9 via a gasket 25 and a cap 26 for preventing dust intrusion is joined to the voice coil bobbin 9 to constitute the speaker A. 29 indicates an input terminal, and 30 indicates a tinsel wire.

Since the voice coil 8 of the speaker A shown in FIG. 1 is connected to the input terminal 29 via the tinsel wire 30, by supplying an acoustic signal to the input terminal 29, the diaphragm 7 is moved, for example, by an arrow F _1. Is driven in the direction shown by F ₁ = M _1.
The sound radiation force of α ₁ acts (here, M ₁ is the equivalent mass of the vibration system of speaker A, and α ₁ is the acceleration acting on diaphragm 7 of speaker A). reaction force -F ₁ acts.

Since the vibration system including the diaphragm 7 of the speaker A of the present invention is separated by compliance via the flexible portion 27 formed on the frame 5, the equivalent mass of the magnetic circuit below the flexible portion 27 is A vibration different from that of the diaphragm 7 is generated.

That is, the vibration system of the speaker A is
Of the diaphragm 7 due to the inertia which tries to stop the function of₁One
Direction sound radiation force F₁= M₁・ Α₁Force F in the opposite direction to_Two
= M _Two・ Α_Two(Where M_TwoIs the flexible part 27 of the frame 5
Equivalent mass including the magnetic circuit below, α_TwoWorks on the magnetic circuit
Acceleration) will work, and the magnetic circuit will have an arrow F_Twoso
The reaction force shown will act.

The acting force F ₂ of opposite direction may be considered as acting force excited by reaction force -F ₁ acting force F ₁ of the diaphragm 7.

Accordingly, the sound radiation force F of the diaphragm 7₁Against
Reaction force -F₁And work below the flexible body 27 of the magnetic circuit
Utility F_TwoReaction force -F_TwoIs F₁= M₁・ Α₁
≒ F _Two= M_Two・ Α_TwoOffset or attenuate each other
Can be done.

Now, assuming that the equivalent mass of the vibration system including the diaphragm 7 of the speaker A is 2 g in FIG.
The overall equivalent mass of the lower magnetic circuit is much heavier than the vibration system, for example, 300 g or more. Accordingly, since the acceleration alpha ₂ applied to the magnetic circuit is a _{α 2 = M 1 / M 1/150} · α 1 from ₂ · alpha ₁ as 2/300 · α _1, a diaphragm 7 of the speaker A is F ₁ = M _If the amplitude of the diaphragm 7 when sound is radiated at ₁ · α ₁ is X ₁ , the amplitude X ₂ including the magnetic circuit below the flexible portion 27 of the frame 5 is X ₂ =
1/150 · X _1, and the influence of the amplitude amplitude X ₂ has on the amplitude X ₁ becomes 1/150.

[0033] That is, in the present invention to create a simple flexible portion 27 to the frame 7, it is possible to cancel or attenuate the reaction force -F ₁ caused by only a vibration plate 7 gives compliance to the magnetic circuit .

FIG. 2 is a side sectional view showing another embodiment of the speaker A of the present invention. In FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted. In FIG.
Is provided between the inclined portion 5b and the bottom 5a of the frame 5 and the flexible portion 27 is provided on the bottom 5a side.

FIG. 3 shows still another embodiment of the loudspeaker according to the present invention. In FIG. 3, the flexible portion 27 is provided on the inclined portion 5b between the bottom portion 5a and the inclined portion 5b. The difference is that the flexible portion 27 is not provided across the opening window 5c of the frame 5 and that the magnetic flux density of the magnetic circuit is increased.

That is, the magnetic circuit is S.S. in the direction opposite to the magnet 1 in the thickness direction to be a ring-shaped cancel magnet. The inner diameter of the second magnet 31 magnetized with N is fitted and joined to the magnet guide 3b of the yoke 3, and a ring-shaped second plate 32 is joined to the upper side of the second magnet 31 via an adhesive. The magnetic gap 4 is formed between the inner diameter of the second plate 32 and the outer diameter of the center pole 3a.

On the second plate 32, a ring-shaped magnet 1 magnetized in the direction opposite to the thickness direction of the second magnet 2 is joined, and the second plate 3
A ring-shaped plate 2 having an outer diameter larger than 2 is joined via an adhesive.

The bottomed cylindrical shield cover 33 surrounds the magnetic circuit so that the bottom surface of the yoke 3 and the outer periphery of the plate 2 are in contact with each other to form a magnetic shield type magnetic circuit. Inner diameter and center pole 3a
The first magnet 32 and the second magnet 32 are pivotably connected to each other in a magnetic gap 4 formed between the outer diameters of the magnet 1 and the second magnet 32.
One magnetic flux is made to pass through the magnetic air gap 4 to increase the magnetic flux density.

FIG. 4 shows still another embodiment of the loudspeaker according to the present invention. A flexible portion 27 is provided at the bottom of the frame 5 and this movable portion is disposed within the diameter of a bottomed cylindrical shield cover 31. It was done.

The magnetic circuit is of a magnetic shield type provided with a second magnet 31 acting as a cancel magnet below the yoke 1.

The loudspeaker A having the structure shown in FIGS. 5 and 6 does not use the equivalent mass of the magnetic circuit below the flexible portion 27 formed on the frame 5 but uses the equivalent mass of the whole loudspeaker A as the diaphragm 7. This is used for canceling the reaction force generated by the action force.

In the embodiment of the speaker A of the present invention shown in FIG. 5, a flange portion 34 is further formed on the outer periphery of the maximum opening diameter portion of the funnel-shaped frame 5, and the same concentric circle as a waveform damper for giving compliance to the flange portion 34. Flexible part 27
Is provided.

In the embodiment shown in FIG. 6, the same compliance as the flexible portion 27 is provided between the yoke 3 having the magnetic circuit having the same structure as that of FIG. Cushioning material 27 such as rubber or foam material
a.

The acting force F ₂ due to the equivalent mass of the entire speaker A in FIG. 5 the diaphragm 7 comprises a frame 5 and the magnetic circuit when moved in the F ₁ direction offset the reaction force -F ₁ of the vibration plate 7 or Operates to attenuate.

The acting force F ₂ due to the equivalent mass of the entire speaker including a magnetic circuit that is placed on the bottom 5a of the frame 5 is as to cancel or attenuate the reaction force -F ₁ of the diaphragm 7 in the configuration of FIG. 6 .

FIG. 7 shows a case where the speaker A of the present invention is disposed in a speaker box 21 having a phase inversion type duct 23. Since the speaker A has been described with reference to FIG. I do.

In the speaker device shown in FIG. 7, the speaker box 21 is molded in a substantially rectangular parallelepiped with ABS resin or the like.
A speaker A similar to that described in detail in FIG. 2 is fixed to a speaker sound emission hole 22a formed in the baffle plate 22.

A baffle board 22 is provided below the speaker A.
And has a first duct 23 having an opening 23a. Furthermore, the phase inversion type first duct 23 overlaps a part of the first duct 23 so as to form a double duct, and a second duct 23b having a diameter larger than that of the first duct 23. The two ducts 23 and 23b extend vertically from the back plate 28 of the speaker box 21 into the speaker box 21 at a predetermined interval between the opening 23c of the second duct 23b and the inside of the baffle board 22. It is configured to be concentric in cross section.

[0049] Thus, F ₁ of the speaker A in the configuration of FIG. 7
The driving force in the direction is offset or attenuated by the equivalent mass M _{2 of the} magnetic circuit disposed on the right side of the flexible portion 27 of the frame 5 and the reaction force generated by the acceleration α ₂ , and the first duct in the speaker box Sound radiation force F _D1 from opening 23a of duct 23 = M _D1 · α _D1 (where M _D1 is the equivalent mass of first duct 23, α _D1 is the acceleration of air moving through first duct 23) the of the reaction force -F _D1 opening 23 of the second duct 23b
c, the acting force at the time of air incidence F _D2 = M _D2 · α _D2 (where M _D2
Is the equivalent mass of the second duct 23b, α _D2 is the acceleration of the air moving in the second duct 23b, and M _D1 ≒ M _D2 , α
_D1 ≒ α _D2 ) are offset or attenuated from each other.

[0050] In the case of FIG. 7, the driving force in the direction indicated magnetic circuits reaction forces -F ₁ sound radiation force F ₁ of the speaker A in the equivalent mass below the flexible portion 27 as an excitation force at F ₂ receiving, reaction force -F ₂ in the F ₂ direction of the driving force of the magnetic circuit
In be like reaction force -F ₁ of the speaker 3 to cancel or attenuate, balancing equation of the speaker A since each other radiant sound is between the first and second ducts 23 and 23b are offset and attenuated F _It suffices to satisfy the condition of ₁ ≒ F ₂ .

Therefore, according to the speaker device of the present invention, the swing of the small and lightweight speaker box can be effectively suppressed.

[0052]

According to the loudspeaker and the loudspeaker apparatus of the present invention, the reaction force of the sound radiation of the speaker can be canceled or attenuated by the reaction force generated by the equivalent mass of the lower magnetic circuit from the flexible portion provided on the frame. The sound radiation power of the speaker can be made larger than usual, and the reaction force of the sound radiation of the speaker can be supported by the structure that does not require a voice coil for driving like an electric / vibration transducer. It is possible to obtain a material that can suppress swinging and the like.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a speaker of the present invention.

FIG. 2 is a side sectional view of another speaker of the present invention.

FIG. 3 is a side sectional view (I) of still another speaker of the present invention.

FIG. 4 is a side sectional view (II) of still another speaker of the present invention.

FIG. 5 is a side sectional view of still another speaker of the present invention (III).
It is.

FIG. 6 is a cross-sectional view (IV) of still another speaker according to the present invention.

FIG. 7 is a side sectional view of the speaker device of the present invention.

FIG. 8 is a partial sectional view of a conventional speaker device.

[Explanation of symbols]

A ‥‥ Speaker, B ‥‥ Electric / vibration transducer,
7 ‥‥ diaphragm, 27 ‥‥ flexible part

Continued on the front page (72) Inventor Kenji Tokushige 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 5D012 BB01 CA09 5D018 AD24

Claims (4)

[Claims] 1. A speaker comprising a magnetic circuit or a flexible means for moving a speaker body in a direction opposite to a vibration system constituting the speaker. 2. The speaker according to claim 1, wherein said flexible means is provided on a frame for holding a vibration system of said speaker. 3. The speaker according to claim 1, wherein a buffer is interposed between the frame of the speaker and the magnetic circuit as the flexible means. 4. A speaker device comprising: a speaker having a magnetic circuit or movable means for moving a speaker body in a direction opposite to a vibration system constituting the speaker, which is disposed in a speaker box.