JPH09252497A - Electromagnetic induction speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need of an insulation processing to be executed to the inner surface of a vibration member or the surface of a magnetic pole by holding the center of a dome part in the vibration member by a fixing member attached to the magnetic pole of a magnetic circuit part and supporting the periphery of the dome part by a supporting member provided on the fixed member. SOLUTION: A diaphragm 1 is in a dome shape and a skirt 2 is provided on the periphery and extended downwards. Also, a first fixing member 15 provided with a shape along the curved surface of the diaphragm 1 is attached to a center pole 7. Then, after passing through a boss 15a provided on the center of the first fixing member 15 to the hole of the diaphragm 1, the hole of a second fixing member 16 is fitted to the boss 15a and the diaphragm 1 is held. Further, a ring-like suspension 14 positioned by a guide groove provided on the first fixing member 15 supports the diaphragm 1. By such a structure, the diaphragm 1 is surely held while being provided with the degree of freedom of vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction type speaker.

[0002]

2. Description of the Related Art FIG. 6 schematically shows an example of the basic structure of a conventionally known electromagnetic induction type speaker. In the figure, a ring-shaped permanent magnet 6 is sandwiched by a ring-shaped yoke 5 and a center pole 7 in the same manner to form a magnetic circuit. A magnetic gap G exists between the yoke 5 and the center pole 7, and a DC magnetic field is generated. Also,
The dome-shaped diaphragm 1 is connected to the center pole 7 via the suspension 3. A conductive skirt 2 is provided around the diaphragm 1. The skirt 2
Extends to the magnetic gap G. A coil 4 is arranged near the skirt 2 and fixed to a yoke 5.

When a signal current flows through the coil 4, the skirt 2 acts as a secondary coil whose both ends are short-circuited, an induction current flows through the skirt 2 by electromagnetic induction, and the diaphragm 1 is vibrated by receiving a force from a DC magnetic field. . The diaphragm 1 can be made compact and lightweight, which is advantageous for reproduction in the high frequency range.

FIG. 7 shows another conventional example. The shaft 9 provided in the fixed member 8 penetrates the hole 1a of the diaphragm 1 and is fitted into the hole 7a provided in the center pole 7. The diaphragm 1 is connected to a center pole 7 via a suspension 3 and is also connected to a fixed member 8 via a suspension 10.

[0005]

However, in the conventional electromagnetic induction type loudspeaker having the above-mentioned configuration, since the adhesive is used to fix the suspensions 3 and 10, the workability at the time of assembly is poor, and It is difficult to hold the diaphragm 1 in a proper position with good balance. Since the conductive skirt 2 provided on the diaphragm 1 may come into contact with the center pole 7 to leak current, an insulation treatment is applied to the inner surface of the skirt 2 or the surface of the center pole 7 to prevent this. Need to be applied. Also, since the acoustic characteristics greatly change depending on the amount of the adhesive applied, it is difficult to obtain stable performance.

The present invention solves these problems in the electromagnetic induction type loudspeaker and securely holds the vibrating member without using an adhesive to eliminate the need for an insulating treatment applied to the inner surface of the vibrating member or the surface of the magnetic pole. Further, the present invention provides an electromagnetic induction speaker that improves workability and yield at the time of assembly and has better performance than conventional ones.

[0007]

In order to achieve the above object, according to the present invention, the center of the dome portion of the vibrating member is held by a fixing member attached to the magnetic pole of the magnetic circuit portion and provided on this fixing member. The supporting member is configured to support the periphery of the dome portion. The fixing member may have a structure including a first fixing member and a second fixing member that sandwich the center of the dome portion. A guide for positioning the support member may be provided on the fixed member.

Further, the vibrating member may be structured to be held by the fixing member via an elastic body in order to improve acoustic characteristics. Further, a sound absorbing material may be arranged in a space between the dome portion and the fixing member in order to absorb an abnormal sound wave generated by reflection of a sound wave inside the vibrating member.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall image of a speaker device according to the present invention. Here, the electrodynamic speaker and the electromagnetic induction speaker are coaxially combined. In the figure, a ring-shaped permanent magnet 6 is sandwiched by a ring-shaped yoke 5 and a center pole 7 in the same manner to form a magnetic circuit. Cylindrical bobbin 11
The coil 4 wound around is located in the magnetic gap G between the yoke 5 and the center pole 7. When a signal current flows through the coil 4, the coil 4 receives a force from the DC magnetic field generated in the magnetic gap G and vibrates by the damper 12. Freely supported bobbin 1
1 vibrates, and further the cone 13 vibrates. The above is the function of the electrodynamic speaker.

At this time, an induction current flows through a conductive skirt 2 (not shown) provided on the diaphragm 1 due to electromagnetic induction of the coil 4, and the diaphragm 1 vibrates by receiving a force from a DC magnetic field. The above is the function of the electromagnetic induction speaker.

FIG. 2 is an enlarged view of the vibrating plate 1 and its vicinity. In this case, the diaphragm 1 has a dome shape, and the skirt 2 surrounds the diaphragm 1.
Is provided and extends downward. The first fixing member 15 having a shape along the curved surface of the diaphragm 1 is attached to the center pole 7. And the first fixing member 1
After the boss 15a provided at the center of the diaphragm 5 is passed through the hole of the diaphragm 1, the hole of the second fixing member 16 is fitted into the boss 15a to sandwich the diaphragm 1. Further, the ring-shaped suspension 14 positioned by the guide groove provided in the first fixing member 15 supports the diaphragm 1. Note that the suspensions 14 may be scattered rather than ring-shaped. With the structure as described above, the diaphragm 1 has a degree of freedom of vibration and is securely held.

FIG. 3 shows a second embodiment. in this case,
Flange portion 1 of flange-shaped first fixing member 15 '
Suspension 14 'is arranged on 5b',
The diaphragm 1 is supported. The diaphragm 1 is an elastic body 1 such as rubber.
First fixing member 15 'and second fixing member 1
It is sandwiched between 6 '. This improves the acoustic characteristics of the diaphragm 1.

As the material of the suspensions 14 and 14 ', for example, an elastic body such as rubber or a viscoelastic body, cloth, felt, glass wool or the like can be considered.
The types of cloth may be natural fibers or synthetic fibers, and mixed spinning, mixed weaving, mixed weaving, or non-woven fabrics thereof.

FIG. 4 shows a third embodiment in which a guide groove is added to the first fixing member 15 in FIG. 2 and the sound absorbing material 18 is arranged in the guide groove. The sound absorbing material 18 is effective for absorbing an abnormal sound wave generated by reflection of the sound wave inside the diaphragm 1, and glass wool or the like is generally used. FIG. 5 shows a fourth embodiment in which the sound absorbing material 18 is arranged on the flange portion 15b 'of the first fixing member 15'.

The structure described above is not limited, and any structure may be used as long as the center of the diaphragm 1 is held by a fixed member and the periphery is supported by a suspension.

[0016]

As described above, in the electromagnetic induction speaker of the present invention, the center of the dome portion of the vibrating member is held by the fixing member attached to the magnetic pole of the magnetic circuit portion, and the fixing member is provided. Since the supporting member supports the periphery of the dome portion, the holding state of the vibrating member is maintained in a stable and well-balanced manner, and the conductive skirt portion of the vibrating member and the magnetic pole of the magnetic circuit portion come into contact with each other to leak current. This prevents the inner surface of the skirt portion or the surface of the magnetic pole of the magnetic circuit portion from being subjected to insulation treatment, and also improves the acoustic characteristics.

Since the diaphragm, the fixing member and the supporting member can be assembled in advance as one block, the workability is good, and since the adhesive is not required for attaching the supporting member, variations in performance are unlikely to occur and the yield is good. .

Further, in the electromagnetic induction type speaker according to the fourth aspect, the acoustic characteristics can be further improved by holding the diaphragm by the fixing member via the elastic body such as rubber.

According to the electromagnetic induction type speaker of claim 5,
By disposing the sound absorbing material between the fixing member and the dome portion, the abnormal sound wave generated by the reflection of the sound wave inside the diaphragm is absorbed, and the acoustic characteristic can be further improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an overall image of a speaker device according to the present invention.

FIG. 2 is a vertical cross-sectional view near a diaphragm.

FIG. 3 is a vertical cross-sectional view of another embodiment.

FIG. 4 is a view in which a sound absorbing material is arranged on the first fixing member in FIG.

FIG. 5 is a diagram in which a sound absorbing material is arranged on the first fixing member in FIG.

FIG. 6 is a diagram showing an example of a configuration of a conventional electromagnetic induction speaker.

FIG. 7 is a diagram showing another example of the configuration of a conventional electromagnetic induction speaker.

[Explanation of symbols]

 1 Vibration Plate 2 Skirt 4 Coil 5 Yoke 6 Permanent Magnet 7 Center Pole 14,14 'Suspension 15,15' First Fixing Member 16,16 'Second Fixing Member 17 Elastic Body 18 Sound Absorbing Material

Claims (5)

[Claims] 1. A cap-shaped vibrating member composed of a dome portion and a conductive skirt portion; a magnetic circuit portion formed so as to generate a direct-current magnetic field and the skirt portion of the vibrating member enters a magnetic gap; In an electromagnetic induction type speaker including a coil for generating a signal magnetic field in a magnetic gap, a supporting member which holds the center of the dome portion by a fixing member attached to a magnetic pole of the magnetic circuit portion and which is provided on the fixing member. An electromagnetic induction type speaker characterized in that the periphery of the dome portion is supported by. 2. The electromagnetic induction speaker according to claim 1, wherein the fixing member is composed of a first fixing member and a second fixing member that sandwich the center of the dome portion. 3. The electromagnetic induction speaker according to claim 1, wherein the fixing member is provided with a guide for positioning the support member. 4. The electromagnetic induction speaker according to claim 1, wherein the vibrating member is held by the fixing member via an elastic body. 5. The electromagnetic induction speaker according to claim 1, wherein a sound absorbing material is arranged in a space between the dome portion and the fixing member.