JPH11136794A - Electroacoustic converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a flat sound pressure distribution over an entire frequency band by providing a diaphragm where plural longitudinal projection parts are arranged in parallel and voice coils wound only around the peripheries of specified plural production parts. SOLUTION: A diaphragm 7 where plural longitudinal projection parts (top parts) 7a1-7a7 are arranged in parallel and voice coils wound only around the peripheries of the specified projection parts (odd-numbered top parts 7a1, 7a3, 7a5 and 7a7, for example) in plural projection parts (top parts) 7a1-7a7. Even if the top parts 7a1-7a7 largely vibrate by the supply of current to the voice coils, the voice coils are prevented from being removed or dropped from the bases of the respective top parts 7a1, 7a3, 7a5 and 7a7. Thus, the respective top parts 7a1-7a7 can uniformly vibrate on paper forward/backward by supplying driving current between speaker terminals. Thus, the diaphragm 7 vibrates in a plane form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroacoustic transducer which is a flat speaker.

[0002]

2. Description of the Related Art FIG. 1 is a view for explaining an electro-acoustic transducer. FIG. 1A is a front view of the electro-acoustic transducer, and FIG. FIG. 2 is a diagram for explaining a diaphragm constituting an electroacoustic transducer,
FIG. 2A is a front view of the diaphragm, and FIG.
FIG. 4 is a view for explaining a wiring state of a driving coil in a conventional electro-acoustic transducer.

As shown in FIGS. 1 (A) and 1 (B), an overall-drive thin speaker unit A, which is an electroacoustic transducer, includes a frame 1, a rear plate 2, a magnet 3, a pole piece 4, a guide pin 5, a boiler. A coil 6, a diaphragm (diaphragm) 7, a damper 8, and an edge 9 are roughly constituted. The area of the diaphragm can be increased by increasing the number of combinations (segments) of the magnet 3, the boil coil 6, and the diaphragm (diaphragm) 7. The dimensions of the speaker unit A are, for example, a thickness of 25 mm,
The width is 115 mm, the height is 136 mm, the maximum amplitude is 10 mmp-p (at 600 gf), and the withstand power is 60 W. In addition, the boil coil 6 is for convenience of illustration,
Although only a part is shown in FIG. 1 (B), as will be described later, the diaphragm 7 is densely wound around the bottoms of the tops 7a1 to 7a7.

The frame 1 is a frame formed of a heat-resistant resin such as a super heat-resistant ABS resin. The frame 1 is screwed and fixed to a speaker cabinet (not shown) via screw holes 1A to 1D provided at four corners thereof (the dimensions of the speaker cabinet are, for example, a thickness of 60 mm and a width of 1 mm).
20 mm, height 500 mm). A rear plate 2 is firmly screwed and fixed to the entire rear side of the frame 1, while four dampers 8 are adhesively fixed to four corners on the front side (diaphragm 7 side). The diaphragm 7 is formed by these four dampers 8.
The four corners are supported so as to freely vibrate.

The rear plate 2 is formed of a metal plate such as iron, and is a base plate for fixing the longitudinal magnets 3 having the longitudinal pole pieces 4 adhered to the upper surface thereof. A large number of air vent slits / holes are provided on the entire rear side of the rear plate 2 and a pair of speaker terminals connected to the start and end of the boil coil 6 are provided (neither is shown). On the other hand, both ends of the long pole piece 4 to which the long magnet 3 is adhered are screwed and fixed with the guide pins 5 on the front side (the diaphragm 7 side) of the rear plate 2 as described above. In the illustrated example, seven longitudinal magnets 3 are provided in parallel with each other.

The magnet 3 is a magnet obtained by sintering ferrite such as strontium ferrite. As described above, when this magnet 3 is fixed to the front side (diaphragm 7 side) of the rear plate 2, one surface of the magnet 3 in contact with the rear plate 2 becomes the N pole, while the magnet 3 in contact with the pole piece 4. The magnet 3 is magnetized so that the other surface (the diaphragm 7 side) of the magnet 3 becomes an S pole. The dimensions of the magnet 3 are, for example, 80 mm in length, 5 mm in width, and 8 mm in thickness.

The pole piece 4 is made of a metal plate such as iron, and has a pair of screw holes at both ends for fixing the magnet 3 to the rear plate 2. The boil coil 6 is provided with top portions 7a1 to 7a7 constituting the diaphragm 7.
Is a coated copper wire sequentially wound around each. As described above, the start and end (not shown) of the boil coil 6 are connected to a pair of speaker terminals provided on the rear plate 2 respectively. The details of winding the boil coil 6 around the tops 7a1 to 7a7 constituting the diaphragm 7 will be described later.

The diaphragm (diaphragm) 7 is made of a polyimide (PI) film that withstands heat generated by the boiler coil 6 and has excellent mechanical properties as a diaphragm, and is integrally molded. Also, in order to reduce the weight of the diaphragm 7,
Although it is necessary to make the diaphragm itself as thin as possible, the thickness of the diaphragm 7 used here was 75 μm. As described above, the diaphragm 7 is mounted on the magnet 3 and the pole piece 4 fixed on the rear plate 2, and the periphery thereof is positioned and fixed to the frame 1 by an edge 9 made of urethane or the like.

The damper 8 supports the diaphragm 7 so that it can vibrate freely, and is made of a thermoplastic resin such as polycarbonate, which is a material having high spring properties, impact resistance and heat resistance. In order to obtain a maximum amplitude of 10 mmpp in a limited space, a multi-stage leaf spring structure is used. Since the dampers 8 are fixed to the four corners of the frame 1, the displacement of each damper 8 is 150 gf and the displacement is 10 mm pp. This load is supported by a four-end support beam structure. Further, the structure is such that the tensile load in the plane direction of the diaphragm 7 is received by the connecting portion at the center of the damper 8. The beam structure is arranged in a fan shape to save space. In addition to the above, the damper 8 may be formed of a soft member such as foamed plastic, cloth sealed with plastic, or a metal member.

The edge 9 firmly adheres and fixes the diaphragm 7 around the entire periphery thereof so that the diaphragm 7 can be uniformly vibrated by an audio signal (drive current). The edge 9 is formed of a soft member such as a foamed plastic or a cloth sealed with plastic, and is usually firmly attached and fixed to the frame 1. As an adhesive used for bonding the diaphragm 7 to the edge 9, an epoxy resin-based or rubber-based adhesive is often used. In some cases, the adhesive may be applied by applying heat and pressure using a similar thermosetting adhesive.

By the way, the above-mentioned diaphragm 7 is shown in FIG.
(B) As shown in FIG.
a7, a flat portion 7b, and an outer peripheral portion 7c. These top portions 7a1 to 7a7, the flat portion 7b, and the outer peripheral portion 7c are integrally formed. The top portions 7a1 to 7a7 are formed in a convex shape (bulge) from the back side (the rear plate 2 side) of the vibrating plate 7 toward the front side.
7 is integrally molded as a main vibrating part 7A. here,
The front side of the vibrating plate 7 is the front side of the thin speaker unit A driven entirely. The tops 7a1 to 7a7 are arranged in parallel in the longitudinal direction of the diaphragm 7 (vertical direction in FIGS. 1A and 2A), and the cross-sectional shape of each of the tops 7a1 to 7a7 is Except for both end portions, in FIG. 2 (B), it has a convex shape (semi-cylindrical shape, semi-cylindrical shape) cut along the line AA ′. An outer peripheral portion 7c is formed around the main vibrating portion 7A. Although only seven apex portions 7a1 to 7a7 are shown in the drawing, it is needless to say that the number can be increased or decreased as necessary.

By supplying an audio signal (driving current) between the pair of speaker terminals of the thin speaker unit A having the above-described structure, the tops 7a1 to 7a7 of the diaphragm 7 are moved with respect to the paper surface. The whole surface vibrates uniformly before and after.

The above-mentioned boil coil 6 is shown in FIG.
As shown in FIG.
7, one boil coil is sequentially wound in close proximity from left to right in FIG. The number of turns of the boil coil 6 wound around each of the tops 7a1 to 7a7 is about 10 turns. One end of the boil coil 6 is connected to a + terminal 10 of a pair of speaker terminals provided on the rear plate 2, while the other end of the boil coil 6 is connected to a − terminal 11 thereof. The boil coil 6 wound around the tops 7a1 to 7a7,
Each of the top portions 7a1 to 7a7 is firmly bonded and fixed to the bottom portion with an adhesive or the like. As a result, even when the tops 7a1 to 7a7 vibrate greatly due to the current being supplied to the boil coils 6, the boil coils 6 are kept at the respective tops 7a1 to 7a7.
It does not peel off or fall off the bottom of the.

By supplying a driving current for vibrating the diaphragm 7 between the speaker terminals 10 and 11 in the direction of the arrow in FIG. 4, the tops 7a1 to 7a7 vibrate uniformly back and forth with respect to the plane of the drawing. I do. As a result, the diaphragm 7 vibrates in a planar manner over the entire surface.

[0015]

As described above, each of the top portions 7a1 to 7a7 arranged in parallel on the diaphragm 7 as described above.
When a driving current is supplied to the boil coil 6 wound around the top, the tops 7a1 to 7a7 vibrate simultaneously back and forth with respect to the paper surface. In this case, as shown in FIG.
A difference occurs in the driving force between the vicinity of both ends 2aa and 2ab of a1 to 7a7 and the vicinity of the center 2ac thereof (the driving force in the vicinity of both ends 2aa and 2ab> the driving force in the vicinity of center 2ac). That is, the top portions 7a1 to 7a7 respond differently to each other.

As a result, the flat speaker A using the wiring state of the conventional driving coil shown in FIG. 4 described above could not obtain a smooth and favorable sound pressure frequency characteristic.

In order to solve the problem that a flat sound pressure cannot be obtained in all frequency bands, the present invention employs, in particular, a plurality of crest-shaped tops 7a1 to 7a7 arranged in parallel on the diaphragm 7 described above. This is to change the wiring state of the wound coil coil 6. Specifically, every other one of the tops 7a1 to 7a7 arranged in parallel,
In addition, the boil coils 6a are attached to the tops 7a1, 7a3, 7a5, 7a7 (or the tops 7a2, 7a4, 7a6).
６6 g are individually wound. As a result, a driving current is supplied to the boil coils 6a to 6g, and each of the tops 7a1 to 7a
Even if a7 vibrates simultaneously with respect to the paper surface, in this case, the tops 7a2, 7a4, 7a6 (or the tops 7a1, 7a7
No drive current is supplied to a3, 7a5, 7a7).
For this reason, unlike the related art, the top portions 7a1 to 7a7 do not generate different displacement responses. Thus, an object is to provide an electroacoustic transducer that can obtain a flat sound pressure in all frequency bands by integrally vibrating the tops 7a1 to 7a7 as the main vibrating portion 7A.

[0018]

In order to solve the above-mentioned problems, the present invention provides an electroacoustic transducer having the following constitutions (1) to (7).

(1) As shown in FIG. 1 to FIG. 3, an electroacoustic transducer (entirely driven thin speaker unit) AA for driving the flat diaphragm 7 over the entire surface, and a plurality of elongated protrusions ( A diaphragm 7 on which tops 7a1 to 7a7 are arranged in parallel, and the plurality of protrusions (tops) 7a1 to 7a7
Specific projections (eg, odd-numbered peaks 7a)
1, 7a3, 7a5, 7a7), and a voice coil 6 wound around only the electroacoustic transducer.

(2) The electro-acoustic transducer (all-over-drive thin speaker unit) AA according to (1), wherein the plurality of projections (tops) 7a1 to 7a1 arranged in parallel on the diaphragm 7 are provided. An electroacoustic transducer according to 7a7, wherein the voice coil 6 is wound only on odd-numbered projections (tops 7a1, 7a3, 7a5, 7a7).

(3) As shown in FIGS. 1 to 3, an electroacoustic transducer (entirely driven thin speaker unit) AA for driving the flat diaphragm 7 over the entire surface, and a plurality of elongated protrusions ( A diaphragm 7 on which tops 7a1 to 7a7 are arranged in parallel, and the plurality of protrusions (tops) 7a1 to 7a7
Specific projections (tops 7a1, 7a3, 7a
5, 7a7) wound around only the voice coil unit 6
a, 6c, 6e, and 6g, and one end of each of the voice coil portions 6a, 6c, 6e, and 6g wound only around the specific protrusions (tops 7a1, 7a3, 7a5, and 7a7). Connection terminals (terminals) aa, ab,
ac, ad, ae, af and the connection terminals (terminal aa-) so that all the voice coil units 6a, 6c, 6e, 6g are connected in series (to form one voice coil 6). A connecting member (voice coil 6) 6b for connecting the terminal ab, the terminal ac-terminal ad, the terminal ae-terminal af);
An electroacoustic transducer comprising: 6d and 6f.

(4) The electro-acoustic transducer (all-surface driven thin speaker unit) AA according to (3), wherein the plurality of projections (tops) 7a1 to 7a7 arranged in parallel on the diaphragm 7 are provided. 2. The electroacoustic transducer according to claim 1, wherein the voice coil unit 6 is wound only on odd-numbered projections (tops 7a1, 7a3, 7a5, 7a7).

(5) The electroacoustic transducer (full-surface driven thin speaker unit) AA according to the above (3 or 4), wherein the voice coil units 6a, 6c, 6e, and 6g are each provided with the specific projection (top). Parts 7a1, 7a3, 7a5, 7a
An electroacoustic transducer characterized by being an annular winding unit having a shape that can be densely inserted in 7) and having a predetermined number of turns (for example, 10 turns).

(6) The electroacoustic transducer (full-surface driven thin speaker unit) A according to any one of the above (3 to 5)
A, wherein the connection member is a conductive wire or a resistance element.

(7) The electro-acoustic transducer (full-surface driving thin loudspeaker unit) AA according to the above item 6, wherein the resistance element as the connection member is provided between the connection terminals (terminal aa-terminal ab, terminal ac-terminal). ad, terminals ae-terminals af) connected in series or in parallel.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electroacoustic transducer according to the present invention will be described with reference to the drawings. FIG. 3 is a diagram for explaining a wiring state of a drive coil in the electroacoustic transducer of the present invention. The same components as those described above are denoted by the same reference numerals, and description thereof will be omitted.

The thin speaker unit AA, which is an electro-acoustic transducer of the present invention, has almost the same configuration as the flat speaker A shown in FIGS. 1 and 2 and is wound around the diaphragm 7 in particular. Only the wiring state of the boil coil 6 is different from that of the conventional fully driven thin speaker unit A.
Therefore, in the following description, only the wiring state of the boil coil 6 wound around the diaphragm 7 will be described.

Now, as shown in FIG. 3, around the tops 7a1 to 7a7 constituting the diaphragm 7, FIG.
From the middle, left to right, the voice coil 6 (6a to 6a)
g) is wound. Specifically, the voice coil 6a,
6c, 6e, and 6g are wound around the odd-numbered top portions 7a1, 7a3, 7a5, and 7a7 of the top portions 7a1 to 7a7. The voice coils 6a, 6c, 6e, 6g are shown in FIG.
As shown in FIG.
3, 7a5, 7a7 (around 10 turns for each top 7a1, 7a3, 7a5, 7a7). Then, the wound voice coil 6a,
The voice coils 6a, 6c, 6e and 6g are firmly fixed between the tops 7a1 to 7a7 from above the tops 6c, 6e and 6g with an adhesive filled between the tops 7a1 to 7a7 (grooves). You.

On the other hand, the voice coils 6a, 6c, 6e, and 6g, which are annular winding units wound a predetermined number of turns, are previously formed independently. And this voice coil 6
a, 6c, 6e, 6g are the tops 7a1, 7a3, 7a
5, 7a7 can be densely inserted. The voice coil 6a, 6c, 6e, 6g having such a shape is attached to the top 7a.
1, 7a3, 7a5, 7a7, fitted around them (set at a time), and then fixing the annular voice coils 6a, 6c, 6e, 6g with an adhesive. Parts 7a1, 7a3, 7a5, 7
A fixed state similar to that obtained by winding the voice coils 6a, 6c, 6e, and 6g around a7 can be obtained. On the other hand, the voice coil 6 is not wound around the even-numbered tops 7a2, 7a4, and 7a6.

FIG. 3 shows a state in which the voice coil 6 is not tightly wound around the tops 7a1, 7a3, 7a5, 7a7 for convenience of explanation. , The voice coil 6 is at the top 7a1, 7a
Needless to say, it is in a state of being tightly wound around 3, 7a5, 7a7.

More specifically, the voice coil 6a having one end connected to the speaker terminal 10 is wound around the top 7a1, and the other end is connected to the terminal aa. A voice coil 6b is connected between terminals aa and ab which are intermediate taps. The voice coil 6c having one end connected to the terminal ab is wound around the top 7a3, and the other end is connected to the terminal ac. A terminal ac which is an intermediate tap,
A voice coil 6d is connected to ad. Further, the voice coil 6e having one end connected to the terminal ad is wound around the top 7a5, and the other end is connected to the terminal ae. A voice coil 6f is connected between terminals ae and af, which are intermediate taps. The voice coil 6g, one end of which is connected to the terminal af, winds the top 7a7,
The other end is connected to the negative terminal 7.

The voice coil 6 serving as a driving coil
a, 5c, 5e, and 5g are top portions 7 constituting the diaphragm 7;
a1, 7a3, 7a5, and 7a7 are firmly adhered and fixed around the bottoms with an adhesive or the like. As a result, the voice coil 6
(5a-5g) is supplied with a current, so that even if the tops 7a1-7a7 vibrate greatly, the voice coil 6
(5a-5g) are the tops 7a1, 7a3, 7a5, 7
There is no peeling or falling off from the bottom of a7. Also,
The voice coils 6b, 6d, 6f are
This is a connection member that is connected to the terminals aa-ab, ac-ad, and terminals ae-af so that 6c, 6e, and 6g are all connected in series (to form one voice coil 6). As shown in FIG. 3, the voice coils 6b, 6d, and 6f are connected with conducting wires in series.

By supplying a driving current for vibrating the diaphragm 7 between the speaker terminals 10 and 11 in the direction of the arrow in FIG. 3, the tops 7a1 to 7a7 vibrate uniformly back and forth with respect to the plane of the drawing. I do. As a result, the diaphragm 7 vibrates in a planar manner over the entire surface.

The top 7 where the voice coil 6 is not wound
a2, 7a4, 7a6 are adjacent tops 7a, respectively.
Since it resonates upon receiving the vibrations of 1, 7a3, 7a5, and 7a7, sound can be output at a sound pressure level equal to or higher than that of the conventional flat speaker A. In this case, the tops 7a1, 7a3, 7a5, 7a7 and the tops 7a2,
Needless to say, no displacement response different from that of 7a4 and 7a6 occurs.

As described above, only the odd-numbered top portions 7a1, 7a3, 7a5, and 7a7 have the voice coil 6 wound around the top portions 7a1 to 7a7. Similarly, by winding the voice coil 6 around the even-numbered tops 7a2, 7a4, 7a6, the speaker terminals 1
The drive current for vibrating diaphragm 7 between 0 and 11 is shown in FIG.
By supplying in the direction of the middle arrow, each top 7a1
7a7 vibrates uniformly back and forth with respect to the paper surface, and as a result,
Needless to say, the diaphragm 7 vibrates in a plane shape over the entire surface.

Specifically, the voice coil 6a having one end connected to the speaker terminal 10 is wound around the top 7a2, and the other end is connected to the terminal aa. Terminals aa, a
The voice coil 6b is connected between b. This terminal ab
The voice coil 6c whose one end is connected to the top 7a
After winding 4, the other end is connected to the terminal ac. The voice coil 6d is connected between the terminals ac and ad. The voice coil 6e having one end connected to the terminal ad is wound around the top 7a6, and the other end is connected to the negative terminal 7.

The wiring state of the voice coil 6 (6a to 6g) described above is such that terminals aa to af, which are intermediate taps, are arranged between the speaker terminals 10 and 11, and these terminals aa to af are arranged.
The sound impedance of the diaphragm 7 can be adjusted by appropriately changing the connection state of the voice coils 6a to 6g connected to f. Specifically, between the terminals aa and ab between the speaker terminals 10 and 11, between the terminals ac and ad,
Instead of all or some of the voice coils 6a, 6d, and 6f connected between the terminals ae and af, an appropriate number of resistance elements and an appropriate resistance value are selected.
Thereby, a plurality of selected resistance elements are connected in series or in parallel. Thereby, the acoustic impedance of the diaphragm 7 can be appropriately adjusted as needed. Further, by selecting and using an appropriate number and an appropriate value of a coil and a capacitor together with a resistance element as needed or individually, the necessary diaphragm 7 can be used.
It is easily conceivable to obtain an acoustic impedance of

Also, through the terminals aa to af, it is possible to apply drive inputs of different phases to the voice coils 6a, 6c, 6e, 6g wound around the tops 7a1, 7a3, 7a5, 7a7. Thereby, for example, the diaphragm 7
The voice coils 6a, 6g wound around the top portions 7a1, 7a7 at both ends of the top portion 7a3,
With respect to the voice coils 6c and 6e wound around 7a5, an input signal supplied to the other terminals between the speaker terminal 10 and the terminal aa, between the terminal af and the -terminal 7, and having an input signal with a predetermined delay. Add. Thereby, the shape of the wavefront of the sound wave radiated from the diaphragm 7 can be adjusted, and a wavefront close to a spherical wave can be realized. Specifically, a method of implementing the method by providing a delay time is conceivable.

Further, the voice coils 6c and 6e wound around the tops 7a3 and 7a5 near the center of the diaphragm 7 have the voice coils 6a and 6g wound around the tops 7a1 and 7a7 at both ends. By using a light wire and a thick wire (or a heavy wire and a thin wire), the shape of the wavefront of the sound wave radiated from the diaphragm 7 can be adjusted without changing the input. It can be performed. Furthermore, the shape of the wavefront of the sound wave radiated from the diaphragm 7 is adjusted without changing the input even by changing the combination of a copper wire, a CCA wire, an aluminum wire, or changing the thickness or the number of windings. Can be.

As a result, the flat speaker AA of the present invention
In particular, in the middle range (about 800 Hz to about 4 kHz), the sound pressure can be suppressed to a maximum of 20 dB. As a result, the dip could be improved to about half of the characteristics of the above-mentioned conventional flat speaker A. As a result, a flatter sound pressure frequency characteristic can be obtained in the middle band, and a flat sound pressure can be obtained in the entire frequency band.

As described above, the above-described flat speaker AA of the present invention comprises a plurality of top portions 7 arranged in parallel on the diaphragm 7.
The voice coils 6 wound around the a1 to 7a7 are alternately placed (odd-numbered tops 7a1, 7a3, 7a5, 7
By individually winding the top portions a7), the top portions 7a1 to 7a7 can be integrally vibrated as the main vibrating portion 7A, and smooth and favorable characteristics can be obtained in all frequency bands.

[0042]

According to the electroacoustic transducer of the present invention having the above-described structure, since the driving force of the diaphragm becomes uniform, undesired vibrations such as divided vibrations can be prevented from occurring. A flat sound pressure can be obtained in the frequency band, and, for example, by appropriately changing the wiring state of the voice coil wound around each top, the acoustic impedance of the diaphragm can be appropriately adjusted, Further, by using a light weight for the voice coil wound around the top, there is an effect that the shape of the wavefront of the sound wave radiated from the diaphragm can be adjusted without changing the input.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an electroacoustic transducer.

FIG. 2 is a diagram for explaining a diaphragm constituting an electroacoustic transducer.

FIG. 3 is a diagram for explaining a wiring state of a drive coil in the electroacoustic transducer of the present invention.

FIG. 4 is a diagram illustrating a wiring state of a drive coil in a conventional electroacoustic transducer.

[Explanation of symbols]

6 Voice coil 6a, 6c, 6e, 6g Voice coil section 7a1-7a7 Top (projection) A, AA Fully driven thin speaker unit (electro-acoustic transducer) aa-af Terminal (connection terminal)

Claims (7)

[Claims] 1. An electro-acoustic transducer for driving a flat plate-like diaphragm over its entire surface, comprising: a diaphragm in which a plurality of longitudinal protrusions are arranged in parallel; and a specific protrusion in the plurality of protrusions An electroacoustic transducer comprising: a voice coil wound only around the periphery of the voice coil. 2. The electroacoustic transducer according to claim 1, wherein the voice coil is wound only on odd-numbered projections of the plurality of projections arranged in parallel on the diaphragm. An electroacoustic transducer characterized by the above. 3. An electro-acoustic transducer for driving a whole of a flat diaphragm, comprising: a diaphragm in which a plurality of longitudinal projections are arranged in parallel; and a specific projection in the plurality of projections. And a connection terminal to which one end of each of the voice coil portions, which is wound only around the specific projection, is connected, and all the voice coil portions are connected in series. A connection member for connecting the connection terminals so as to be connected to each other. 4. The electro-acoustic transducer according to claim 3, wherein, in the plurality of protrusions arranged in parallel on the diaphragm, the voice coil unit is wound around only odd-numbered protrusions. An electro-acoustic transducer, characterized in that: 5. The electro-acoustic transducer according to claim 3, wherein the voice coil portion has a shape that can be densely inserted into the specific protrusion and has a predetermined number of turns. An electroacoustic transducer, which is a winding unit. 6. The electroacoustic transducer according to claim 3, wherein the connection member is a conductive wire or a resistance element. 7. The electro-acoustic transducer according to claim 6, wherein the resistance elements as the connection members are connected in series or in parallel between the connection terminals.