JPH11243593A - Loudspeaker and loudspeaker device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loudspeaker which lowers the resonance sharpness at its lowest resonance frequency and increases this resonance frequency toward low bands by drilling plural pores through a diaphragm having an airtight cap by means of an air-passable damper. SOLUTION: A voice coil 12 which is wound round a voice coil bobbin 11 is put into a magnetic air-gap part 7 of a magnetic circuit, and the bobbin 11 is held via an air-passable damper 17 having corrugation that can be vertically vibrate. The inner diameter of a funnel-shaped diaphragm 10 having a free or fixed edge 9 of paper, etc., is bonded to the upper outer diameter part of the bobbin 11. Then the largest diameter part of the diaphragm 10 is fixed to the fringe part of upper opening of a frame 8 via a gasket 19. A cap 22 made of a highly airtight material is bonded to the upper end of the bobbin 11 or the sloping part of the diaphragm 10, so as to airtightly cover the upper end of the bobbin 11. Then plural small through-holes 21 air pierched through the sloping part of the diaphragm 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small and lightweight speaker and a speaker device, and more particularly to an improvement of a small speaker and a speaker device in which the minimum resonance frequency and the resonance sharpness are small.

[0002]

2. Description of the Related Art Conventionally, as an effective means for extending the low-frequency reproduction limit of a speaker device, for example, an opening and a duct are provided in a baffle plate provided with a speaker, and a phase of a sound emitted from a back surface of a diaphragm of the speaker is adjusted. A bass reflex type (phase inversion type) speaker device which inverts and radiates to the outside through an opening through a duct to enhance the sound wave emitted from the diaphragm of the speaker to the front so as not to distort the bass range is well known. Have been.

[0003] Such a phase inversion type speaker device is shown in FIG.
As shown in FIG. 1A, a speaker 3 is fixed so as to face a speaker sound emission hole 2a formed in a baffle plate 2 provided on a front surface of a speaker box 1.

As shown in FIG. 3A, for example, the speaker 3 is provided with a ring-shaped magnet 4, a plate 5 and a yoke 6 attached so as to sandwich the ring-shaped magnet 4, and an inner periphery of the plate 5. A magnetic gap 7 is formed between the side and the center pole 6a of the yoke 6. A frame 8 of the speaker 3 is mounted on the plate 5, and an edge 9 is provided on an outer peripheral portion of the frame 8, and the outer peripheral portion of the cone-shaped diaphragm 10 is held by the edge 9.

On the other hand, a voice coil bobbin 11 is mounted on the inner peripheral portion of the diaphragm 10, and a voice coil 12 is wound around the voice coil bobbin 11, and the voice coil 12 is fixed by a center pole 6a of the plate 5 and the yoke 6. It is designed to be inserted into the formed magnetic gap 7. Reference numeral 17 denotes a damper for holding the voice coil 12 in the magnetic gap 7.

An acoustic signal from an input terminal 13a provided at a predetermined position outside the speaker box 1 is connected to a connection line 1
4a to the terminal 15 of the speaker 3 via the terminal 15a.
Of the voice coil 12 via the tinsel wire 16
To supply.

[0007] Further, the speaker sound emission hole 2a of the baffle plate 2
A duct 18 having an opening 18a is provided on the same surface as the above, and the phase of the sound emitted from the back surface of the diaphragm 10 of the speaker 3 is inverted and radiated from the duct 18 to the outside of the speaker box 1. The bass range of the sound coming out from the front is expanded.

As described above, an electrical equivalent circuit of the phase inversion type speaker device can be represented as shown in FIG.

3 (A) and 3 (B), S ₀ is the stiffness of the support system of the speaker 3, M ₀ is the equivalent mass of the support system of the speaker 3, R _ms0 is the mechanical resistance of the speaker support system,
_m0 is the mechanical resistance of the air loading of the speaker, R ₀ is expressed by R _m0 + R _ms0 = R ₀ equivalent mechanical resistance of the speaker. S _C is the stiffness in the speaker box 1, R _D is the mechanical resistance of the air load in the duct 18, and M _D is the air mass in the duct 18.

[0010] With above phase inversion type speaker apparatus as in, to be able to lower the bass reproduction limit compared to sealed, about 80% of the bass resonance frequency f ₀ of the speaker 3
It is said that the low-frequency reproduction range can be extended to a degree.

In such a speaker device, in FIG. 3A, the sound radiation force F ₁ caused by the vibration of the diaphragm 10 of the speaker 3 is equal to the acceleration α ₀ acting on the diaphragm 10 of the speaker at the equivalent mass M ₀ of the speaker 3, ie, F ₁ = M ₀ α ₀ To such sound radiation force F _1, the reaction force -F ₁ toward the speaker box 1 from the rear side of the diaphragm 10 also becomes remarkable the smaller the volume of the speaker box 1 speaker device is small and light, The vibration of the diaphragm 10 causes the speaker box 1
The air inside is repeatedly compressed and expanded, and this air is
There is a problem that the speaker box 1 is rocked because it acts as a force for returning 0 to the original position, and the bass reproduction is hindered.

In order to solve such a problem, the present applicant has previously proposed a speaker device as shown in FIG. 4. In FIG. 4, portions corresponding to those in FIG. 3 are denoted by the same reference numerals.

In FIG. 4, a speaker box 1 is formed of a synthetic resin into a box shape integrally with a baffle plate 2. The speaker 3 having the same configuration as that described in detail with reference to FIG. 3A is fixed to the speaker sound emission hole 2a formed on the upper side of the baffle plate 2. First duct 1 arranged below baffle plate 2
8 and the opening 18a are integrally formed when the baffle plate 2 is formed.

Further, a speaker sound emission hole 2b is formed at a position opposite to the speaker sound emission hole 2a formed on the baffle plate 2 above the rear face plate 1B, and the second speaker 3b, preferably, the speaker 3 and the back surface are connected. Is fixed to the rear plate 1B so that the first
Second duct 18b having a larger duct diameter than the second duct 18
Are overlapped within a predetermined length of the first duct 18 and are planted integrally with the rear plate 1B so as to form a concentric cross section, and the first through the opening 18c of the second duct 18b.
Equivalent mass M of air radiating to the opening 18a of the duct 18
_D and the equivalent resistance _RD are configured to be large.

Further, the first and second speakers 3 and 3b
Are supplied with the same input acoustic signal via input terminals 13a and 13b and connection lines 14a and 14b disposed on the rear panel 1B.

According to the speaker device shown in FIG.
Radiation force F _D1 between the first and second ducts 18 and 18b
And _{F D2 / 2 + F D2 /} 2 of the reaction force -F _D1 and -F _D2 /
2 + (− F _D2 / 2) are canceled out, so that the first and second
Loudspeakers 3 and 3b reactive force -F ₁ and -F ₂ of radiation force F ₁ and F ₂ of F ₁ ≒ F ₂ Tosureba can each other to cancel.

[0017]

However, the above-described structure requires a pair of speakers 3 and 3b having substantially the same structure in the speaker box 1, making it difficult to reduce the size of the speaker box 1 and increasing the cost. There was a problem.

Furthermore, in the conventional small speaker, the magnet of the magnetic circuit for driving the diaphragm is very small, and the voice coil is wound around a small-diameter voice coil bobbin to increase the sound pressure of the speaker. The resonance sharpness (hereinafter referred to as Q ₀ ) of the frequency (hereinafter referred to as f ₀ ) increases.

[0019] Also, can not play the expansion of the low-pass If you have provided to the large size speaker of such a Q ₀ in the speaker box of small volume, in Q ₀ is the low frequency range for further increases in the f ₀ There is a problem that the sound quality of the sound is remarkably deteriorated.

In general, a very small speaker often uses a fixed edge, which simultaneously forms an edge when the diaphragm is made, but the fixed edge of such a small speaker is hard and the voice coil is lightweight, so that the speaker is light. There is a problem that it is also difficult to lower f ₀ of.

Further, the vibration system of the speaker was made equal.
With one speaker, the higher the f _0, the greater the Q in proportion to f ₀ , and thus there is a problem that it is unsuitable for low-frequency reproduction.

An object of the present invention is to provide a speaker device which solves the above-mentioned problems, and an object to be solved by the invention is to provide one speaker using an inexpensive diaphragm such as a fixed edge. To reduce the Q ₀ and shift the speaker f ₀ to the low frequency side to obtain a speaker device capable of widening the low frequency range and emitting high quality low frequency radiation and preventing vibration of the lightweight speaker box. Things.

[0023]

A speaker device according to the present invention uses a breathable damper, and a plurality of fine holes are formed in a diaphragm having an airtight cap.

[0024] capable larger f ₀ lower the Q ₀ of the speaker by an equivalent mass of air passing through the plurality of through holes that bored in the diaphragm, according to the speaker apparatus of the present invention to the low frequency side is obtained.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A small speaker according to the present invention will be described below in detail with reference to FIGS. Note that parts corresponding to the speakers shown in FIGS. 3 and 4 are denoted by the same reference numerals.

FIG. 1A is a plan view of the speaker device of this embodiment, FIG. 1B is a side sectional view, 3 is a small speaker of this embodiment as a whole, and yoke 6 is a plate material such as pure iron. , A cylindrical center pole 6a erected at the center of the disc-shaped portion, and a stepped portion formed on the disc-shaped portion concentrically with the center pole 6a. Are integrally formed.

The ring-shaped driving magnet 4 magnetized in the thickness direction of ferrite or the like is adhered on the disc-shaped portion of the yoke 6 via an adhesive. The inner diameter of the ring-shaped driving magnet 4 is fitted and positioned in the step portion of the magnet guide portion 6b formed in the disk-shaped portion of the yoke 6.

The plate 5 is joined to the driving magnet 4. In this case, place the gap guide on the center pole 6
a while keeping it inserted in a.
Is applied to the upper surface of the gap guide, and the inner diameter of the plate 5 is inserted into the outer diameter of the gap guide to be fixed by bonding. The plate 5 is made of a pure iron or the like in a disk shape, and is made of a perforated plate material having a through hole formed in the center, and a voice coil is formed in a magnetic gap 7 formed between the inner peripheral edge of the through hole and the outer diameter of the center pole 6a. 12 are provided.

The metal part of the magnetic circuit is formed by fixing a frame 8 formed in a funnel shape of steel or the like to the plate 5. Below the magnetic gap 7, the outer periphery of the center pole 6 a and the inner diameter of the magnet 4 are formed. The second space 20b surrounded by
Is formed.

The voice coil 1 wound around the cylindrical voice coil bobbin 11 is provided in the magnetic gap 7 of the above magnetic circuit.
2 is inserted, and the voice coil bobbin 11 is held via a breathable damper 17 having a corrugation of a waveform capable of vibrating in a vertical direction.

The inner diameter of the damper 17 is joined to the upper end of the voice coil bobbin 11 via an adhesive, and the outer diameter is joined to the outer periphery of the bottom of the frame 8. Further, the inner diameter of a funnel-shaped diaphragm 10 having a free or fixed edge 9 made of paper or the like is joined to the upper outer diameter portion of the voice coil bobbin 11, and the maximum diameter portion of the diaphragm 10 is joined to the upper opening peripheral portion of the frame 8. Is fixed through a gasket 19.

At the upper end of the voice coil bobbin 11 or at the inclined portion of the diaphragm 10, a cap 22 is formed in a dome shape together with a bonding portion 23 made of a highly airtight material such as aluminum. It is joined via an adhesive to cover.

As shown in the plan view of FIG. 1A, the diaphragm 10 of the present invention is provided with a plurality of thin through holes 21 at appropriate positions on the inclined portion of the diaphragm 10.

Further, the tinsel wire 16 is connected to the voice coil 12, and an audio signal is supplied to the voice coil 12 via an input terminal 15 attached to the frame 8.

By assembling the small speaker as described above, the first space 20a and the second space 20b between the diaphragm 10 and the upper surface of the plate 5 are formed.

It is well known that the low-frequency characteristic of the vibration system of the speaker 3 is generally determined by Q _{0 at} f ₀ .

Now, let the effective mass of the speaker vibration system be M ₀ ,
The stiffness of the vibration supporting portion is S ₀ , the internal resistance of the output amplifier is R ₀ , the resistance of the voice coil is Rv, the length of the voice coil is Lv (cm), the mechanical resistance of the vibration system is Rm, and the internal volume of the speaker box is Assuming that the stiffness is Sc, the resistance in the speaker box is Ra, and the magnetic flux is Bg, Q ₀ can be expressed by the following equation (1).

As is apparent from the above equation (1), when the diaphragm 10 is driven, a plurality of through holes 2 formed in the diaphragm 10 are formed.
Air resistance Rm passing through the hole 21 through the 1 increases, (1) the denominator increases, it is clear that acts as reducing the value of Q _0.

Accordingly, the transition of f _{0 to} the high frequency side can be prevented with the decrease of Q ₀ , the low frequency band is expanded, and a speaker device capable of emitting high-quality low frequency band can be obtained.

FIG. 2 shows a case where the speaker 3 shown in FIG. 1 is disposed in a speaker box 1 having a phase inversion type duct 18. The speaker box 1 has the same configuration as that described in FIG. Therefore, redundant description is omitted.

The above-mentioned speaker box 1 is made of ABS resin or the like and has a small and light weight of about 1 to 3 liters.
An acoustic signal when the diameter of the speaker 3 is also thought the following diameters 8φcm supplied from the terminal 13a to the voice coil 12, the driving force of the diaphragm F ₁ direction by driving the speaker 3 F ₁ = M ₀ α ₀ and reaction force -F ₁ acts.

On the other hand, assuming that the number of the plurality of through-holes 21 formed in the inclined portion 10 of the diaphragm 10 is n, these through-holes 21 are relatively thick in the diaphragm 10 such as a fixed edge. A duct-like effect is produced in the portion
From the back side of the second space 2 through the first space 20a.
Generating a reaction force -F _D / n to the action force F _D / n by the air entering the 0b.

Accordingly, such F _D / n + F _D / n + こ の
‥ = When it ask balanced so as to be F ₁ using the two speakers 3 and 3b as described in FIG. 4 to cancel the reaction force -F ₁ and -F ₂ and reaction forces likewise -F ₁ - (F _D
/ N + F _D / n + ‥‥) can be offset to some extent.

In this case, F ₁ > (F _D / n + F _D / n + ‥
‥), it is difficult to set F ₁ ≒ (F _D / n + F _D / n + ‥‥), but it is clear that the offset effect can be expected to some extent.

When the radiation force at the opening 18a of the duct 18 when the phase inversion duct 18 shown in FIG. 2 is provided is F _D1 and the reaction force thereof is -F _D1 , the speaker box 1 is swung. The conditional expression to prevent this is: F ₁ + F _D1 = (W +
F ₁ + F _D1 ) R may be selected. In the above equation, W represents the weight of the speaker device, and R represents the frictional resistance between the bottom surface of the speaker box 1 and the mounting portion.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a diaphragm 1 having a diameter of 6.5 φcm according to the present invention will be described.
F when a plurality of through-holes are drilled and when no drilling is performed
₀ and Q ₀ as well as an example of measurement of mechanical sharpness (Q _M) together with comparative examples.

First, as a comparative example, Q _M , when a speaker 3 having a size of 6.5 mm is disposed in a closed box (capacity of 1000 liters) or a JIS box such as an infinite baffle plate,
Q ₀ and f ₀ are shown below. (A) In the case of a speaker without a perforated hole 21 Q _M = 4.88 Q ₀ = 2.79 f ₀ = 170 Hz (b) The perforated hole 21 having a diameter of 0.7 mm is equal in angle from the center of the diaphragm 10. in the case of the 12 opening in the inclined portion speaker _{Q M = 4.74 Q 0 = 2.74} f 0 = 166Hz

Next, Q _M , Q ₀ , and f ₀ when the same speaker 3 having a diameter of 6.5 φcm is installed in a 1-liter speaker box are as follows: (c) A speaker Q _M having no through-hole 21 = 7.3 Q ₀ = 4.2 f ₀ = 245 Hz (d) In the case of a loudspeaker in which twelve 0.7-diameter through-holes 21 are opened in the inclined portion at an equal angle from the center of the diaphragm 10, Q _M = 5. 15 Q ₀ = 3.2 f ₀ = 195 Hz.

As is evident from the above measurement results, in the case of the present invention, the rise of f ₀ can also be shifted to the lower frequency side of 195 Hz from 245 Hz, and Q is the resonance sharpness at the lowest resonance frequency f _{0. Since 0} can also be reduced from 4.2 to 3.2, even a small and inexpensive speaker expands the low range,
A loudspeaker and a loudspeaker device capable of improving low-frequency sound quality can be obtained.

In the above-described embodiments and examples of the present invention, the number of through holes formed in the diaphragm 10 is set to 12, but this number n
Is extremely increased, the response of the mid-range characteristic is reduced. Therefore, it is preferable to suppress the number to less than 15. Also, if the number is reduced, the effect of the present invention cannot be obtained, so at least three or more through holes are required.

Further, the size of the through holes 21 is preferably 3 mmφ or less in diameter, and the positions of the through holes need not be formed at equal angles within a range of 360 degrees from the center of the diaphragm as shown in FIG. It is clear that it may.

[0052]

The lowest resonance frequency f ₀ in at resonance sharpness Q ₀ value the diaphragm by drilling can be reduced only a thin hole low band resonance frequency f _0, according to the speaker of the present invention, according to the present invention
To the lower frequency side. Further, a speaker device capable of attenuating the reaction force of the speaker can be obtained only by disposing one speaker having a through hole in the diaphragm in the speaker box.

[Brief description of the drawings]

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

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

FIG. 3 is a sectional view of a conventional speaker device and an electrical equivalent circuit diagram thereof.

FIG. 4 is another side sectional view showing the configuration of a conventional speaker device.

[Explanation of symbols]

1 speaker box, 3, 3b speaker, 10
{Vibration plate, 18} Duct, 21} Through hole

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mie Matsushita 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (2)

[Claims] 1. A speaker having a diaphragm using a breathable damper and an airtight cap, wherein the diaphragm has a plurality of pores. 2. A speaker device comprising: a speaker having a plurality of fine holes formed in a diaphragm; and a speaker arranged opposite to a speaker sound emission hole in a speaker box having a phase inversion duct.