WO2018051480A1

WO2018051480A1 - Electroacoustic conversion device

Info

Publication number: WO2018051480A1
Application number: PCT/JP2016/077381
Authority: WO
Inventors: 賢太田中
Original assignee: 賢太田中
Priority date: 2016-09-16
Filing date: 2016-09-16
Publication date: 2018-03-22
Also published as: JPWO2018051480A1

Abstract

[Problem] With regard to an electroacoustic conversion device, to facilitate miniaturization and, in particular, thinning, and the stabilizing of characteristics. [Solution] A drive magnet 37 and a pole piece 39 are fixed in a yoke 35. Fixed to the yoke 35 is a ring-shaped flange part 45 which is thinner than the yoke 35, and which protrudes in the outer circumferential direction at the end of the yoke 35. At the outer circumferential edge of the flange part 45, an annular attachment section 45b is disposed in an extending manner, and an annular contact section 45c is disposed in an extending manner on the outside of the attachment section 45b. A vibration film 47 is attached to the attachment section 45b so as to cover the pole piece 39 and the flange part 45. A voice coil 49 is fixed to the vibration film 47, and the voice coil is inserted between the pole piece 39 and the yoke 35. The inner wall of a case body 53 comes into contact with the contact section 45c.

Description

Electroacoustic transducer

The present invention relates to an electroacoustic transducer, and in particular, an improvement of an earphone and a headphone worn on a user's ear or head, a speaker device such as a large speaker, and an electroacoustic transducer usable as a microphone. About.

Conventionally, as a speaker device to be worn on a user's ear, for example, as shown in FIG. 6, one end face of a drive magnet 5 is fixed in a cup-shaped yoke 3 disposed in a case body 1. A thin vibration film 7 facing the other end face is fixed to the tip of the yoke 3 with an adhesive or the like, and a cylindrical voice coil 9 fixed to the vibration film 7 is slightly attached to the outer periphery of the drive magnet 5. A configuration in which they are inserted with a large interval is well known.

The case body 1 includes a funnel-shaped base 1a and a front cover 1b that covers the tip (right side in FIG. 6). A flexible eartip (ear pad, earpiece) is formed on the outer periphery of the sound passage cylinder 11 protruding from the front cover 1b. ) 13 is fitted.

In addition, the code | symbol 15 in FIG. 6 is a cable led out outside, and this knot 15a exists in the base 1a.

In this speaker device, the drive unit 17 that vibrates the vibration film 7 is formed by the drive magnet 5 and the voice coil 9, and a sound signal is generated by vibrating the vibration film 7 by applying an audio signal to the voice coil 9 from the outside with the cable 15. The generated sound is propagated to the outside from the sound passage cylinder 11 on the front surface of the diaphragm 7.

The speaker device as an actual product is configured, for example, as an external ear canal insertion (canal) type earphone device, and a vibration is generated in the concha cavity 25 surrounded by the user's tragus 19, anti-tragus 21, and concha 23. The case body 1 is inserted so that the membrane 7 is close to the concha 23, and the ear tip 13 is elastically brought into contact with the inner wall of the external auditory canal 27 extending from the concha cavity 25 to the eardrum (not shown). used.

As shown in FIG. 6 described above, the actual product includes a coaxial type in which the center axis of the sound passage cylinder 11 is aligned with the center axis of the vibration membrane 7, and although not shown, the sound passage is performed on the center axis of the vibration membrane 7. There is a non-coaxial type in which the central axis of the cylindrical body 11 is set obliquely. FIG. 6 shows a state where the earphone device is attached to the left ear.

Incidentally, as a known example of the earphone, there is JP 2010-283643 A (Patent Document 1), and as a known example of the speaker device, there is JP 2008-118331 A (Patent Document 2).

JP 2010-283634 A JP 2008-118331 A

However, if the configuration of the speaker device shown in FIG. 6 is slightly modified so as to be easily understood and shown in detail, for example, FIG. 7 is obtained.

That is, in the speaker device described above with reference to FIG. 7, the cup-shaped yoke 3 has a through-hole 3b at the center of the bottom 3a, and the open end of the cylindrical portion 3c of the yoke 3 is bent outward. A piece 3d is provided, and the outer peripheral portion of the tip of the support piece 3d is slightly raised along the axial direction to form an annular fixing portion 3e.

Further, in the yoke 3, the driving magnet 5 and the ring plate-shaped pole piece 29 are overlapped and fixed to the yoke 3 bottom 3 a by, for example, a fit 31, and an annular fixing portion coated with an adhesive (not shown) is applied. The outer periphery of the diaphragm 7 is directly fixed to 3d, the support piece 3d and the pole piece 29 are covered with the diaphragm 7, and the voice coil 9 fixed to the diaphragm 7 is inserted between the pole piece 29 and the yoke 3 It has become.

Reference numeral 33 in FIG. 7 denotes a circuit board to which an audio signal is supplied from the outside via the cable 15 (see FIG. 6). The audio signal is applied from the circuit board 33 to the voice coil 9 via a lead wire (not shown). The

In addition, a flexible adhesive (not shown) is applied to the inside of the front end of the front case 1b of the case main body 1 and the rear side space E of the annular fixing portion 3e of the yoke 3, so that the yoke 3, that is, the speaker main body is the front case 1b (main body case). It is fixed to 1).

In such a configuration shown in FIG. 7, the vibration membrane 7 is generally bonded and fixed to the annular fixing portion 3 e with an adhesive, and when the speaker body is inserted into the main body case 1, the annular fixing portion 3 e is the front surface. The step 1c of the cover 1b is brought into contact with the vibrating membrane 7 therebetween.

The vibrating membrane 7 is fixed to the annular fixing portion 3e with the above-described flexible adhesive in order to facilitate vibration due to the vibration of the voice coil 9, but this portion contacts the step portion 1c of the front cover 1b. In the case of contact, uneven pressing due to non-uniform pressing or a gap due to fitting or the like is likely to occur, and the vibration film 7 is likely to be deformed, which becomes distortion during vibration of the vibration film 7 and hardly stabilizes the performance.

Further, the yoke 3 is obtained by forming a magnetic metal plate, for example, an iron plate by progressive pressing, from the viewpoint of the necessity of forming a magnetic circuit between the drive magnet 5 and the pole piece 29 or cost reduction. ing.

Therefore, due to the features of the press work, the support piece 3d portion needs to have a plate thickness of 0.5 mm because it is necessary to form a magnetic circuit as the yoke 3 of the small speaker, and it is a performance to make it thinner than this. Leading to deterioration.

Also, due to the nature of the assembly work, for example, it is necessary to prevent the flexible adhesive that attaches the vibrating membrane 7 from flowing out to the support piece 3d shown in FIG. For this reason, in the case of a small speaker, it is generally difficult to make the annular fixing portion 3e start up smaller than 0.6 mm, and at least less than 0.4 mm, and the dimension S1 (0 from the lower surface of the support piece 3d to the tip of the annular fixing portion 3e. .9 to 1.1 mm) is limited.

That is, in the above-described configuration, there is a limit to downsizing the dimension along the axial direction, and there is room for improvement.

Moreover, the vibrating membrane 7 attached to the annular fixing portion 3e of the support piece 3d is cut from a large resin sheet to a diameter slightly larger than the outer diameter of the annular fixing portion 3e from the viewpoint of facilitating the attachment. Since it affixes on the cyclic | annular fixing | fixed part 3e, the outer periphery of the vibration film 7 protrudes from the outer periphery of the cyclic | annular fixing | fixed part 3e.

Therefore, the dimension S2 between the annular fixing portion 3e of the support piece 3d and the inside of the front case 1b of the case body 1 needs to be about 0.12 mm. Also from this point, the outer diameter of the front case 1b, that is, the case body 1 is required. It tends to be an obstacle to downsizing.

Further, since the support piece 3d of the yoke 3 extends in the horizontal direction from the cylindrical portion 3c, a predetermined amount of adhesive is applied to the inside of the front end of the front case 1b of the case body 1 and the back side space E of the annular fixing portion 3e of the yoke 3. Therefore, the length of the open end (lower end in FIG. 7) side of the front case 1b (main body case 1) needs to be increased as indicated by reference numeral S3. It is blocking.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an electroacoustic transducer that can be easily further reduced in size, in particular, reduced in thickness, and can easily stabilize its characteristics.

In order to solve such a problem, the configuration of the electroacoustic transducer of the present invention includes a cylindrical magnetic yoke, and one end face is fixed in the yoke, and a magnetic circuit is formed between the yoke. A driving magnet, a pole piece superimposed on the driving magnet at the tip end side of the yoke and forming a magnetic circuit with the yoke, and a ring-shaped flange portion formed thinner than the yoke, the yoke A flange portion fixed to the yoke so as to protrude in the outer peripheral direction at the front end portion, a sticking portion formed in an annular shape at the outer peripheral edge portion of the flange portion, and an outer side of the sticking portion at the outer peripheral edge portion of the flange portion The outer periphery was directly attached to the affixing part so as to face the abutting part formed concentrically with the pole piece and the flange part at a distance from each other. A voice coil that is formed into a cylindrical shape by winding a thin insulating film and a thin insulated conductor, and is fixed to one side of the vibration film on the yoke side, and is inserted into an annular gap between the outer periphery of the pole piece and the yoke, A voice coil that vibrates the diaphragm by an applied audio signal; and a case main body that abuts the inner wall against the abutting portion and supports the yoke inside via the flange portion.

The configuration according to the electroacoustic transducer of the present invention may be a configuration in which the affixing portion protrudes in a convex shape over the entire circumference of the outer peripheral edge of the flange portion.

The configuration according to the electroacoustic transducer of the present invention may be configured such that the contact portion extends at a level lower than the affixing portion at the outer peripheral edge portion of the flange portion.

The configuration according to the electroacoustic transducer of the present invention may be a configuration in which the contact portion extends from the affixing portion at the same level at the outer peripheral edge of the flange portion.

In the configuration of the electroacoustic transducer according to the present invention, the contact portion is formed to extend on the outer peripheral edge portion of the flange portion through an annular concave groove formed along the outside of the sticking portion. Other configurations are possible.

The configuration according to the electroacoustic transducer of the present invention may be a configuration in which the flange portion is formed of a magnetic material and is inserted and supported so as to overlap the inner wall of the yoke.

In such a configuration according to the electroacoustic transducer of the present invention, a ring-shaped flange portion formed thinner than the yoke, and a flange portion fixed so as to protrude in the outer peripheral direction at the tip portion of the yoke; An affixing portion formed in an annular shape at the outer peripheral edge of the flange portion, an abutting portion formed in an annular shape outside the adhering portion at the outer peripheral edge of the flange portion, and the inner wall against the abutting portion. And a case body that supports the yoke inside through the flange portion. The flange portion is not a component of the magnetic circuit. It is easy to stabilize the variation.

In the configuration according to the electroacoustic transducer of the present invention, if the affixing portion is formed so as to protrude in a convex shape over the entire circumference of the outer peripheral edge of the flange portion, the vibrating membrane can be easily placed and fixed on the affixing portion.

In the configuration according to the electroacoustic transducer of the present invention, if the contact portion is extended at a level lower than the affixing portion at the outer peripheral edge portion of the flange portion, the thickness can be further reduced.

In the configuration according to the electroacoustic transducer of the present invention, the flange portion shape can be simplified and thinned by extending the contact portion at the same level from the sticking portion at the outer peripheral edge portion of the flange portion. is there.

In the configuration according to the electroacoustic transducer of the present invention, if the abutting portion is extended through an annular groove formed along the outer peripheral edge of the flange portion on the outer side of the sticking portion. It is easy to place and fix the vibrating membrane on the sticking part.

In the configuration according to the electroacoustic transducer of the present invention, if the flange portion is formed of a magnetic material and is inserted and supported by being overlapped with the inner wall of the yoke, the leakage portion and the reactive magnetic flux are reduced. A strong magnetic circuit is formed between the yoke and damping, and a quick response vibration is easily secured.

It is a principal part longitudinal cross-sectional view which shows embodiment which concerns on the electroacoustic transducer of this invention. It is a partial expanded sectional view which expands and shows the principal part of the electroacoustic transducer of this invention. FIG. 2 is a bottom view of a vibrating membrane according to the electroacoustic transducer in FIG. 1. It is a schematic longitudinal cross-sectional view which shows the electroacoustic transducer of FIG. 1 as an earphone apparatus. It is a schematic longitudinal cross-sectional view which shows another electroacoustic transducer as an earphone apparatus. It is sectional drawing which shows the conventional electroacoustic transducer with a usage example. It is a reference longitudinal cross-sectional view for demonstrating the electroacoustic transducer of FIG.

Hereinafter, an embodiment of an electroacoustic transducer according to the present invention will be described with reference to the drawings, taking a speaker device, for example, an earphone device as an example.

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of a speaker device according to the present invention.
In FIG. 1, the yoke 35 is formed into a cup shape from a magnetic plate material, and a through hole 35b is formed at the center of the bottom 35a.

A cylindrical (ring) drive magnet 37 is accommodated in the yoke 35 so that the hollow portion 37a is aligned with the through hole 35b. That is, the drive magnet 37 is accommodated in the yoke 35 with one end face (lower side in FIG. 1) overlapped with the bottom 35a so as to surround the through hole 35b.

On the other end face (upper side in FIG. 1) of the drive magnet 37, a pole piece 39 formed in a ring shape having the same diameter as or slightly larger than the outer shape of the drive magnet 37 has this through hole 39a in the hollow portion 37a. They are stacked so that they are aligned.

On the outer side of the bottom 35a of the yoke 35, a circuit board 41 having through holes 41a is overlaid so that the through holes 35b and the through holes 41a are aligned.

The yoke 35, the drive magnet 37, the pole piece 39, and the circuit board 41 are formed of, for example, a tubular fitting 43 that is inserted from the pole piece 39 or the circuit board 41 side through the hollow portions 37a and 39a and the through holes 35b and 41a. The two ends are coaxially integrated and fixed to the bottom 35 a of the yoke 35.

The yoke 35, the drive magnet 37, the pole piece 39, and the circuit board 41 may be coaxially integrated with an adhesive (not shown) or the like and fixed to the yoke 35.

The pole piece 39 is formed of a magnetic material for concentrating magnetic flux to obtain high sound quality, and the outer periphery of the pole piece 39 faces the circumference of the cylindrical portion 35c of the yoke 35 at substantially the same level and at a slight interval. A magnetic circuit is formed between them (hereinafter the same), but can be identified with the drive magnet 37.

A ring-shaped flange portion 45 made of a magnetic metal material such as iron and having a thickness smaller than that of the yoke 35 is fixed to the tip of the cylindrical portion 35c of the yoke 35 so as to protrude from the yoke 35 toward the outer periphery. Yes. The flange portion 45 is formed thinner than the yoke 35 by, for example, about ½.

The flange portion 45 is bent and extended so that the outer peripheral side of the flat ring plate portion 45a rises to an oblique outer periphery in the drawing, and as shown in FIG. 2A, the sticking portion 45b extends over the entire periphery of the outer peripheral edge portion. It is formed in an annular and integral manner in a convex shape.

The affixing part 45b of the flange part 45 is formed to extend at the outer peripheral edge of the flange part 45 at a level where the surface of the abutting part 45c is lower than the surface of the affixing part 45b. The abutting portion 45c is abutted in a case main body 53 described later.

Referring back to FIG. 1, in the flange portion 45, the insertion tube portion 45d is bent so as to hang downward from the inner peripheral edge of the ring plate portion 45a. The flange 45 is supported and fixed to the yoke 45 by being press-fitted or welded to the inner wall of the cylindrical portion 35 c of the yoke 35.

As shown in FIG. 3 shown from the pole piece 29 side, the vibration film 47 is formed in a disk shape from a conventionally known thin insulating film material, and a relatively wide central portion is slightly inflated into a dome shape. A central region 47a and an outer peripheral region 47b concentrically surrounding the central region 47a in an annular shape are provided. Reference numeral 49a in FIG. 3 is a lead wire at both ends of a voice coil 49 to be described later, and is omitted in other drawings.

Although not shown, a bent portion is formed in the central region 47a of the vibration film 47 by bending a film material by providing a folded shape, a radial shape or a concentric circular rib, and the central region 47a has rigidity so that it is difficult to bend. ing.

Although not shown, the outer peripheral region 47b is formed with radial fine irregularities called a so-called corrugation edge. Compared with the central region 47a, the outer peripheral region 47b is easily bent and is resistant to vibration. Flexibility is high.

That is, the central region 47a is harder to bend than the outer peripheral region 47b and has a strong rigidity. However, it is important that the vibration range including the central region 47a is within a rigidity range in which good vibration is ensured.

As shown in FIG. 1, the vibration film 47 covers the flange portion 45 and the pole piece 39 with a space and overlaps the entire outer edge of the outer peripheral region 47b on the sticking portion 45b. It is adhesively fixed to the pasting part 45b with an agent (not shown).

On one surface side (the lower surface side in FIG. 1) of the vibrating membrane 47, one end surface side of the cylindrical voice coil 49 surrounds the central region 47a at the annular boundary between the central region 47a and the outer peripheral region 47b. It is fixed.

The voice coil 49 is formed by winding a thin insulated conductor wire with insulation coating into a cylindrical shape, and is integrated with the inner wall of the cylindrical portion 35c (insertion cylindrical portion 45d) of the yoke 35, the outer periphery of the drive magnet 37 and the pole piece 39. The yoke 35 and the drive magnet 37 and the pole piece 39 are inserted with a slight space therebetween, and face the ring between the inner wall of the yoke 35 and the outer periphery of the drive magnet 37 and the pole piece 39.

The lead wires 49a at both ends from the voice coil 49 are led out from diagonal positions, and the hollow portion of the tubular fitting 43, that is, the through hole 39a of the pole piece 39 and the hollow portion 37a of the drive magnet 37, and the bottom portion 35a of the yoke 35, The circuit board 41 is led out through the through holes 35b and 41a and connected to the circuit board 41 (see FIG. 3).

An audio signal is supplied to the circuit board 41 superimposed on the bottom 35a of the yoke 35 from an electronic device (both not shown) by a cable.

When the voice signal is applied to the voice coil 49, the voice coil 49 is displaced, and the vibration film 47 is driven to vibrate.

That is, the yoke 35, the insertion cylindrical part 45d, the drive magnet 37, the pole piece 39, and the voice coil 49 form a drive part 51 that vibrates and drives the vibration film 47, and the main part (speaker) of the so-called internal magnet type speaker device. Main body).

As shown in FIG. 4, the yoke 35 has a sticking portion 45 b and a contact portion 45 c of the flange portion 45 fitted in a cap-shaped case main body 53 and supported in the case main body 53.

The case main body 53 described above includes a large-diameter cylindrical portion 53a into which the outer periphery of the yoke 35 is fitted, and a small-diameter cylindrical portion 53b that is continuous from the large-diameter cylindrical portion 53a and has a smaller diameter than the yoke 35. It is integrally molded from resin or the like.

The yoke 35, the drive magnet 37, and the pole piece 39 are integrated and fitted inside the large-diameter cylindrical portion 53a, and the inner step portion 53c formed so as to reduce the inner diameter of the large-diameter cylindrical portion 53a has a flange. 45 contact portions 45c are in contact.

That is, the outer peripheral edge portion of the flange 45 allows the fixed portion of the vibration film 47 and the contact portion to the case main body 53 to function as separate portions.

In terms of the manufacturing process, after inserting the yoke 35, the flange 45, etc. into the case main body 53, a back side space E (see FIG. 5) formed between the rear side of the flange 45 and the inner wall of the case main body 53 (large diameter cylindrical portion 53a). 1), an adhesive (not shown) is applied to fix the yoke 35 and the like to the case body 53.

The small-diameter cylindrical portion 53b of the case body 53 covers the vibrating membrane 47 with a space therebetween, and extends so as to protrude upward in FIG.

In the speaker device having the above-described configuration, the open front end portion of the cap-shaped cover 55 is press-fitted inside the open front end of the large-diameter cylindrical portion 53a in the case main body 53, and the cover 55 is formed into a large-diameter cylindrical shape with an adhesive (not shown). It is fixed to the open (end) side of the portion 53 a, and the yoke 35 and the circuit board 41 are covered with a cover 55.

A flexible ear tip 57 is fitted on the outer periphery of the small-diameter cylindrical portion 53b to be commercialized as an earphone device.

In such a speaker device, by supplying an audio signal from the cable via the circuit board 41 and applying the audio signal to the voice coil 49, the drive unit 51 vibrates the vibrating membrane 47, and The vibration sound is propagated to the outside through the small-diameter cylindrical portion 53b.

And as shown in FIG. 6 mentioned above, the speaker device according to the present invention houses the case main body 49 in the concha cavity 25 surrounded by the tragus 19, the tragus 21, and the concha 23, The ear tip 57 at the tip is inserted into the ear canal 27 and used.

In the above-described speaker device according to the present invention, since the flange portion 45 is not a component of the magnetic circuit, it does not require a thickness (0.5 mm) for configuring the magnetic circuit like the yoke 3 of the conventional example, For example, sufficient strength can be obtained even with a thickness of about 0.2 mm.

Moreover, in the structure which concerns on the speaker apparatus of this invention, the sticking part 45b mentioned above is protrudingly formed and formed over the perimeter of the outer peripheral edge part of the flange part 45, and this becomes a positioning means and becomes the vibrating membrane 47. Can be easily mounted and fixed on the sticking portion 45b.

Furthermore, in the configuration according to the speaker device of the present invention, the contact surface of the contact portion 45c extends at a level lower than the application surface of the application portion 45b at the outer peripheral edge of the flange portion 45. Further reduction in thickness is possible.

For example, as shown in FIGS. 2A and 2B, when the thickness of the flange portion 45 is 0.2 mm, the thickness including the contact portion 45c and the pasting portion 45b can be formed with a dimension of about 0.4 mm. is there.

Further, since it can be extended at a level lower by, for example, about 0.1 mm than the pasting portion 45b at the outer peripheral edge portion of the flange portion 45, it is 0.9 to 1.1 mm of the conventional symbol S1 in FIG. It can be formed as thin as 0.5 to 0.7 mm.

In the case of the insertion type earphone shown in FIG. 6, the wearability to the ear is greatly improved by forming the outer peripheral portion thinly as in the present invention. Helps reduce pain or pressure.

Further, since the ring plate portion 45a does not form a magnetic circuit except that the insertion cylindrical portion 45d contributes to a strong magnetic circuit, the flange portion 45 satisfies the strength requirements including prevention of abnormal vibration of the speaker. In this case, it is possible to make it thin.

For this reason, it can be formed with a thickness about half that of the yoke 35, and the rising dimension of the affixing portion 45b for fixing the vibration film 47 can be reduced to ½ or less of the conventional one. It is easy to make the dimension along the axial direction of the flange portion 45 (corresponding to reference sign S1 in FIG. 7) smaller than 1/2 of the conventional size.

In addition, since the contact portion 45c is provided on the outer periphery of the sticking portion 45b for fixing the vibration membrane 47, the outer diameter of the vibration membrane 7 is larger than the outer diameter of the sticking portion 45b and the vibration membrane 7 protrudes from the sticking portion 45b. The gap (corresponding to symbol S2 in FIG. 7) between the sticking portion 45b and the large-diameter cylindrical portion 53a is as small as possible, for example, as small as about 0.05 mm.

Therefore, the present invention can contribute to the significant reduction of the defect rate, the prevention of variation in performance, and the improvement of performance without changing the outer diameter dimension so much as the conventional product.

Further, since the flange portion 45 is formed of a magnetic material and the insertion cylindrical portion 45d is inserted and supported by being overlapped on the inner wall of the yoke 35, a strong magnetic circuit is formed between the flange portion 45 and the yoke 35, There is an advantage that vibration with quick response and damping is easily secured.

In the earphone type, if the flange 45, which is the speaker edge, is thin, it can be easily attached to the concha and the sound quality can be easily improved by increasing the caliber.

Furthermore, in the back side space E formed between the inside of the large-diameter cylindrical portion 53a of the case body 53 and the back side of the yoke 35 (flange portion 45), 0.1 to 0.1 indicated by symbol S2 in FIG. The gap of about 0.15 mm is narrowed to about 0.02 mm in the present invention, and this makes it easy to reduce the size.

In the conventional configuration, the performance due to the gap S2, due to many factors such as eccentricity during speaker insertion, variation in pressing pressure during insertion, variation in adhesive layer thickness, variation in adhesive protrusion, variation in vibration film protrusion, etc. It was a cause of defects.

The present invention solves the above problems all at once, and the gap between the inside of the large-diameter cylindrical portion 53a and the outer edge portion (contact portion 45c) of the flange portion 45 in FIG. It is also possible, and this also causes a significant drop in performance defects.

Moreover, since the flange portion 45 has a sticking portion 45b that is bent and extended so that the outer peripheral side of the flat ring plate portion 45a rises obliquely to the outer periphery in the drawing, the front case 1b (main body case 1) is opened. Even if the length on the end side (reference numeral S3 in FIG. 7) is shortened, a predetermined amount of adhesive can be applied, and also in this respect, downsizing is possible.

Further, the speaker device according to the present invention may have a configuration other than the above-described configuration, for example, a configuration as shown in FIG. 2B.

2B, the outer peripheral edge of the ring plate portion 45a of the flange portion 45 is formed with an abutting portion 45e extending from the sticking portion 45b at the same level.

Moreover, the contact portion 45e is formed to extend outside the sticking portion 45b via an annular concave groove 45f formed along the same. That is, the sticking part 45b, the concave groove 45f, and the contact part 45e are continuously formed concentrically.

2B, the yoke 35 and the flange portion 45 are fitted in the case main body 53, and the contact portion 45e of the flange portion 45 is connected to the step on the inner wall of the case main body 53 as shown in FIG. The yoke 35 is supported and fixed in the case main body 53 by being brought into contact with the portion 53 c and bonded and fixed with an adhesive (not shown).

In FIG. 5, the configuration other than the contact portion 45e and the concave groove 45f is substantially the same as that in FIG. 4, and therefore detailed description of FIG. 5 is omitted.

In the configuration related to the speaker device shown in FIGS. 2B and 5, the contact portion 45 e extends from the sticking portion 45 b at the same level at the outer peripheral edge portion of the flange portion 45, thereby simplifying the shape of the flange portion 45 and Thinning is possible.

Furthermore, since the contact part 45e is extended in the outer peripheral edge part of the flange part 45 through the annular groove 45f formed along the outer side of the sticking part 45b, the vibration film 47 is provided. Is easily placed and fixed on the affixing portion 45c.

Moreover, in terms of practical use, there is an advantage that the concave groove 45f becomes a buffer band that clearly separates the affixing portion 45b and the abutting portion 45e.

By the way, in the speaker device of the present invention, in addition to the configuration in which the sound passing cylinder formed by the small diameter cylindrical portion 53b of the case main body 53 projects along the central axis of the case main body (small diameter cylindrical portion) 55, the central axis Alternatively, a configuration that projects in an oblique direction is also possible.

The electroacoustic transducer of the present invention can be widely used as a speaker device such as a headphone or a large speaker, and further as a microphone.

DESCRIPTION OF SYMBOLS 1, 53 Case main body 1a Base part 1b Front cover 1c, 53b Step part 3, 35 Yoke 3a, 35a Bottom part 3b, 35b, 39a, 41a Through-hole 3c, 35b Cylindrical part 3d Support piece 3e Annular fixed part 5, 37 Drive magnet 7, 47 Vibration membrane
9, 49 Voice coil 11 Sound passing cylinder 13, 57 Ear tip (ear pad, ear piece)
15 Cable 15a Knots 17 and 51 Drive unit 19 Tragus 21 Pair of beads 23 Ear concha 25 Ear concha 27 27 Ear canal 29, 39 Pole pieces 31, 43 Fitting 33, 41 Circuit board 37a Hollow part 45 Flange part 45a Ring plate Portion 45b affixing portion 45c, 45e abutting portion 45d insertion cylindrical portion 45f concave groove 47a central region 47b outer peripheral region 49a both ends lead wire 53a large diameter cylindrical portion 53b small diameter cylindrical portion 55 cover E rear side space

Claims

A cylindrical magnetic yoke;
A drive magnet having one end face fixed in the yoke;
A pole piece that overlaps the drive magnet on the tip side of the yoke and forms a magnetic circuit with the yoke;
A ring-shaped flange portion formed thinner than the yoke, wherein the flange portion is fixed to the yoke so as to protrude in an outer peripheral direction at the tip end portion of the yoke;
An affixed portion formed in an annular shape at the outer peripheral edge of the flange portion,
A contact portion formed concentrically with the outer peripheral edge of the flange portion on the outer side of the sticking portion;
A thin vibration membrane in which the outer periphery is directly attached to the attaching portion so as to face the pole piece and the flange portion with a gap therebetween,
A voice coil that is formed in a cylindrical shape by winding a thin insulated conductor, and is fixed to one side of the vibration film on the yoke side, and is inserted into an annular gap between the outer periphery of the pole piece and the yoke. A voice coil that vibrates the diaphragm with a voice signal
A case body that abuts the inner wall against the abutting portion and supports the yoke inside via the flange portion;
An electroacoustic transducer characterized by comprising.
2. The electroacoustic transducer according to claim 1, wherein the affixing portion is formed to protrude in a convex shape over the entire circumference of the outer peripheral edge of the flange portion.
3. The electroacoustic transducer according to claim 1, wherein the contact portion is formed to extend at a level lower than the pasting portion at the outer peripheral edge portion of the flange portion.
The electroacoustic transducer according to claim 1 or 2, wherein the contact portion is formed to extend from the sticking portion at the same level at the outer peripheral edge portion of the flange portion.
5. The electroacoustic transducer according to claim 4, wherein the abutting portion is formed to extend on the outer peripheral edge portion of the flange portion on the outer side of the sticking portion through an annular concave groove formed along the outer circumferential edge portion.
The electroacoustic transducer according to any one of claims 1 to 5, wherein the flange portion is formed of a magnetic material and is inserted and supported so as to overlap the inner wall of the yoke.