JP4514270B2 - Multi-functional pronunciation body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-function sounding body that is incorporated in a mobile communication device such as a mobile phone or a pager and notifies a user of an incoming call by sound or vibration.
[0002]
[Prior art]
In general, portable devices such as those described above are configured to be used by switching between generating a buzzer sound or melody sound to notify the user of an incoming call, and vibrating without producing a sound. A structure has been adopted in which a sound generating body for generating sound and a vibrating body that generates vibration by rotating an eccentric weight with a small motor are incorporated. Incorporating both the sounding body and the vibrating body in this way is disadvantageous in terms of downsizing and cost reduction of the device, but in recent years, one sounding body that generates both sound and vibration has been used. It came to be able to. Some of this type of sounding body can also be used for voice output when talking in a hands-free state.
[0003]
FIG. 3 shows a multifunctional sounding body disclosed in Japanese Patent Application Laid-Open No. 10-257594. The magnetic circuit unit 1 includes a short cylindrical center pole 2a and a yoke 2 composed of a flange 2b, an annular magnet 3, and a top plate 4. A magnetic gap is formed between the outer periphery of the center pole 2 a and the inner periphery of the top plate 4. The magnetic circuit unit 1 is supported by a first suspension 5 having a curved cross section and joined to the upper end of a support member 6 'to constitute a mechanical vibration system. A disc-shaped first diaphragm 7 is joined to the upper end of the support member 6 ', and a third disc whose cross section is curved in a waveform is supported by the lower end of the support member 6'. The diaphragm 13 is joined, and the voice coil 8 is located in the magnetic gap of the magnetic circuit unit 1. A sealed first cavity 10 is formed between the magnetic circuit unit 1, the first suspension 5, and the first diaphragm 7, and the first cavity 5 is formed between the first suspension 5 and the third diaphragm 13. Two vacant chambers 14 are formed, and the second vacant chamber 14 communicates with the outside through the vent hole 6'a.
[0004]
When an alternating electrical signal is input to the voice coil 8 of this multifunctional sound generator, an alternating electromagnetic force acts between the voice coil 8 and the magnetic circuit unit 1. If the frequency of the electrical signal is somewhat high and is in the audible frequency range, the third diaphragm 13 to which the voice coil 8 is fixed vibrates to generate sounds such as a buzzer sound and voice, while the first suspension. The magnetic circuit portion 1 supported by 5 hardly vibrates because of its low natural frequency. If the electrical signal is a relatively low frequency below the audible frequency band, the third diaphragm 13 hardly vibrates and no sound is produced, and conversely, the magnetic circuit unit 1 vibrates, and this vibration is generated. The sound is transmitted to the device incorporating the sounding body through the support member 6 ', and the user is notified of the incoming call by vibration instead of sound.
[0005]
[Problems to be solved by the invention]
In order for such a multifunctional sound generator to notify the user of an incoming call by vibration, the vibration portion of the sound generator must have a large vibration energy so that the vibration is sufficiently transmitted to the device incorporating the sound generator. The most effective way to increase the vibration energy is to increase the mass of the vibration part, but on the other hand, downsizing of the device is required and the direction is contrary to the increase of the mass. An object of the present invention is to maximize the mass of a magnetic circuit section in a small multifunction sounding body. Another object of the present invention is that the gap between the lower surface of the voice coil and the upper surface of the flange of the pole piece is reduced in order to reduce the size of the product, and these may collide during vibration of the magnetic circuit unit or the diaphragm. It is to increase the gap so that there is no.
[0006]
[Means for Solving the Problems]
Conventionally, in the multi-function type sounding body that has appeared on the market, the magnetic circuit section has a short cylindrical magnet joined to the inner side of a yoke of a deep dish-shaped magnetic material with a short cylindrical edge, and the magnetic surface is magnetized on the upper surface of the magnet. Since the top plate of the body is joined and the magnet is located inside the voice coil, it has been limited to what is called the inner magnet type. On the other hand, in the present invention, an outer magnet type magnetic circuit is used.
[0007]
In the magnetic circuit of the outer magnet type, the magnetic path has a pole piece consisting of a center pole, which is a short cylindrical portion, and a flange. And an annular top plate is joined to the upper surface of the magnet. The magnetic circuit portion is elastically supported by a support spring and accommodated in the cover. The support spring may support the magnetic circuit unit 1 only on one of the upper surface side and the lower surface side when viewed in a cross section like the first suspension 5 of the conventional example of FIG. In some cases, the magnetic circuit unit 1 is supported on both upper and lower surfaces.
[0008]
The diaphragm to which the voice coil is fixed has a curved shape with an uneven surface in order to obtain the required vibration characteristics. In the present invention, the magnetic circuit components facing the diaphragm, that is, the center pole and the top plate are used. The end face is an uneven surface shaped like a diaphragm. That is, in the conventional example of FIG. 3, the end face of the magnetic circuit component remains flat, but in the present invention, it is built up on this, and this build up increases the mass compared to the conventional magnetic circuit unit. . In the present invention, the clearance between the voice coil and the flange is increased by providing an annular recess on the upper surface of the flange of the pole piece below the voice coil.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1A and 1B show a first embodiment of a multifunctional sounding body according to the present invention, in which FIG. 1A is a plan view, and FIG. For ease of understanding, FIG. (A) is drawn with the diaphragm 34 seen in FIG. (B) removed. A magnetic circuit portion 33 is accommodated in a case where a cover A (31) made of resin and a cover B (32) are abutted, and the magnetic circuit portion 33 is a magnetic material pole comprising a short cylindrical center pole 38a and a flange 38b. An annular magnet 37 is joined to the flange 38b of the piece 38, and a top plate 39 of the same annular magnetic material is joined to the upper surface of the magnet 37.
[0010]
The inner peripheral part of the support spring A (36) is fixed to the top plate 39 by spot welding or other means, and the outer peripheral part of the support spring A (36) is fixed to the cover B (32) by bonding or insert molding. The part 33 is elastically supported to constitute a vibration part. As shown in FIG. 1A, the support spring A (36) has a shape in which two arc-shaped arm portions 36b extend from the inner peripheral portion 36a and are connected to an annular outer peripheral portion 36c. Since the support spring is thus annular, the outer shape of the case can be circular. Reference numeral 36d denotes a ground terminal, which works to prevent electrostatic breakdown of the circuit by escaping static electricity carried by the magnetic circuit unit 33 to the ground when it is incorporated into an external circuit.
[0011]
As shown in FIG. 1B, the magnetic circuit portion 33 is supported on the lower surface side by another supporting spring B (42). The support spring B (42) has substantially the same shape as the support spring A (36), and the inner peripheral portion is fixed to the pole piece 38 by spot welding or the like, and the outer peripheral portion is fixed to the cover A (31). Thus, by using two support springs, it is easy to adjust the spring constant, and the stress generated in each spring can be reduced, and the magnetic circuit portion 33 is supported on both upper and lower sides. Therefore, the rolls of the upper and lower surfaces are prevented from being tilted, so that they do not tilt and come into contact with the coil during vibration. However, in order to make the spring characteristics as uniform as possible in the lateral direction, the two support springs are attached with their plane shapes shifted by 90 °. The support spring B (42) does not require a ground terminal.
[0012]
As shown in FIGS. 1A and 1B, the outer periphery of the flange 38b of the pole piece 38 is provided with two protrusions 38c outward on both sides of the center. Since the tip is close to the inner periphery of the cover A (31), it is possible to prevent the magnetic circuit portion 33 from being excessively displaced in the lateral direction and damaged when receiving an impact. Protruding portions 38c are provided only in two places and are not allowed to approach the cover on the entire circumference of the flange 38b. One of the reasons is that the air resistance received by the flange increases and the magnetic circuit portion 33 is free. This is because vibration is inhibited.
[0013]
As another reason, as shown in FIG. 1 (B), the support spring B (42) is in close contact with the flange 38b and the projecting portion 38c of the pole piece 38 or has only a very narrow gap. When the circumference is made close to the inner wall of the cover, when the magnetic circuit portion 33 is to be displaced downward, the arm portion of the support spring B (42) cannot be bent with overlapping the flange 38b. This is because cannot be displaced downward. Therefore, the protruding portion 38c is provided only in the vicinity of the portion where the arm portion of the support spring B (42) is connected to the inner peripheral portion.
[0014]
The outer periphery of the diaphragm 34 is fixed to the upper surface of the cover B (32), and the voice coil 35 is fixed to the diaphragm 34. The voice coil 35 includes the outer periphery of the center pole 38a and the inner periphery of the top plate 39. Is located in the magnetic gap formed by The magnetic ring 40 is provided to shield the magnetic circuit portion 33 and prevent the generated magnetic field from leaking outside the case. The cover B is provided with two connection terminals 41 for connection with an external circuit, and the end of the winding of the voice coil 35 is connected to this by soldering or the like.
[0015]
The operation of the multi-functional sounding body of the present invention is the same as that of the conventional example. When a signal current is passed through the voice coil 35 through the connection terminal 41, an alternating electromagnetic force is generated between the magnetic circuit unit 33 and the voice coil 35. If the frequency of the signal is in the audible frequency band, the vibration plate 34 vibrates to generate sound, and if the frequency is lower than that, the vibration of the vibration plate 34 becomes smaller and no sound is generated. The magnetic circuit portion 33 supported by the spring A (36) and the support spring B (42) mechanically vibrates, and the vibration is transmitted to the device incorporating the case through the case to notify the user of an incoming call.
[0016]
As described above, in order for the multi-function sound generator to reliably attract the user's attention, the energy of vibration must be large, and it is effective to increase the mass of the vibration part as much as possible. Therefore, in the present invention, in the multifunctional sound generator of FIG. 1, first, a samarium / cobalt magnet having a large specific gravity is used instead of a ferrite magnet or the like that is generally used as a material of the magnet 37.
[0017]
Next, as shown in FIG. 1B, the upper surface of the center pole 38a of the pole piece 38 is formed into a convex surface with a raised central portion. The diaphragm 34 has various curved shapes on the cross section to obtain a required compliance. In the embodiment of FIG. 1, the diaphragm 34 has an arch shape with the center portion protruding upward, and the upper surface of the center pole 38a is The convex surface is substantially the same as this, so that when the magnetic circuit portion 33 approaches the diaphragm 34 during vibration, the gap between the lower surface of the diaphragm 34 and the upper surface of the center pole 38a is substantially uniform. .
[0018]
In the conventional example of FIG. 3, the end face (lower side in FIG. 3) of the center pole 2a is a plane although the cross section of the third diaphragm 13 is curved in a waveform, but the present invention of FIG. In the embodiment, as compared with the case where the upper surface of the center pole 38a is flattened as in the conventional example of FIG. Mass is increasing.
[0019]
FIG. 2 shows a second embodiment of the present invention. In the previous embodiment of FIG. 1, the central section of the diaphragm 34 is convex upward, and the upper end of the center pole 38a is also convex accordingly. In the embodiment of FIG. 2, the diaphragm 34 is upward. The upper end of the center pole 38a is also concaved accordingly. In this case as well, the mass of the blacked portion is increased compared to the case where the upper end of the center pole is flattened. Further, in FIG. 2, the top surface of the top plate 39 is also slightly built up as much as possible due to the relationship with the diaphragm 34.
[0020]
Making the upper end of the center pole 38a concave as shown in FIG. 2 has the following advantages over making it convex as shown in FIG. That is, in FIG. 1 (B), the center portion of the center pole 38a is most thickened, but in FIG. 2 is the outer periphery of the center pole 38a. The overlap with the part is a1 in FIG. 1B, a2 in FIG. 2, and a2 is larger than a1. When the magnetic circuit unit 33 and the diaphragm 34 vibrate and the center pole 38a and the diaphragm 34 are displaced in directions away from each other, this overlap may be lost and the voice coil 35 may ride on the upper surface of the center pole 38a. , A2> a1, so that the upper end of the center pole 38a having a concave surface as shown in FIG. 2 has less risk of the voice coil 35 riding on the upper surface of the center pole 38a than the convex surface of FIG.
[0021]
Another matter in the present invention is that, as seen in FIGS. 1B and 2, the recess 43 is formed around the center pole 38 a around the upper surface of the flange 38 b of the pole piece 38, and the annular shape has the same diameter as the voice coil 35. It is to provide. During vibration, the lower end of the voice coil 35 approaches the upper surface of the flange 38b. However, in a small sounding body, the thickness of the magnet 37 and the like are minimized, so that the gap between the lower end of the voice coil 35 and the upper surface of the flange 38b is reduced. In some cases, the gap cannot be sufficiently removed. Therefore, by providing the recess 43 on the upper surface of the flange 38b directly below the voice coil 35, the distance between them is increased. As a result, the generation of noise due to the collision between the two during vibration and the damage to the parts are prevented. The recess 43 can be easily provided 8 by press working or the like. In FIG. 1 and FIG. 2, the cross section of the recess 43 is arcuate, but of course it may be rectangular or other shapes.
[0022]
【The invention's effect】
As described above, the present invention uses a samarium-cobalt magnet having a large specific gravity for the magnetic circuit and realizes the relationship between the top surface of the pole piece and the top plate with the diaphragm when realizing the multi-function sounding body of the outer magnet type. In order to increase the mass of the magnetic circuit portion, which is the vibrating portion, as much as possible. According to this structure, an additional part for weight is unnecessary. Further, a recess is provided on the upper surface of the flange of the pole piece below the voice coil to ensure a gap between the lower end of the voice coil during vibration and the upper surface of the flange. As a result, it is possible to obtain a multifunctional sounding body that is small, thin, excellent in performance and reliability, and inexpensive.
[Brief description of the drawings]
FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line BB of FIG.
FIG. 2 is a cross-sectional view of another embodiment of the multifunctional sounding body of the present invention.
FIG. 3 is a cross-sectional view of a conventional multi-function sound generator.
[Explanation of symbols]
1, 33 Magnetic circuit section 2 Yoke 3, 37 Magnet 4, 39 Top plate 5 First suspension 7 First diaphragm 8, 35 Voice coil 13 Third diaphragm 34 Diaphragm 36 Support spring A
36a Inner peripheral part 36b Arm part 36c Outer peripheral part 38 Pole piece 38a Center pole 38b Flange 38c Projection part 42 Support spring B
43 recess

Claims (3)

An outer magnet type magnetic circuit unit is formed by fixing an annular magnet around the center pole to the flange of a pole piece having a center pole and a flange, and further fixing an annular top plate on the upper surface of the magnet. Form the
Elastically supporting the magnetic circuit part in the cover by at least one support spring;
Attach the diaphragm to which the voice coil is fixed to the cover, and configure the voice coil to be located in the magnetic gap created by the outer circumference of the center pole and the inner circumference of the top plate.
The cross section of the diaphragm has an uneven shape, a concave surface is formed at the upper part of the center pole, and the end face of the center pole facing the diaphragm is formed into a concave surface similar to the cross sectional shape of the upper diaphragm. The multifunctional sounding body is characterized in that the end surface of the center pole is fluffed more than when it is flat . The multifunctional sound generator according to claim 1,
The end face of the top plate facing the diaphragm is formed in an uneven surface similar to the cross-sectional shape of the upper diaphragm, and the end face of the top plate is fluffed more than when flat. Multi-functional pronunciation body. In the multifunctional sounding body according to any one of claims 1 and 2,
A multifunctional sounding body characterized in that a concave portion is provided on an upper surface of a flange of a pole piece that contacts the lower side of the voice coil to increase a distance from the voice coil.

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