JP2002186089A - Micro speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro speaker that can enhance the assembly and the performance of the product by eliminating restrictions in a conventional micro speaker such that a winding end of a voice coil of the micro speaker is led out from an adhered section of the voice coil to a diaphragm or adhered to a lower face of the diaphragm. SOLUTION: A recessed part 1d is formed around a part at which the winding end 9 is led out from the voice coil 5 by providing a notch on a cylindrical part of a yoke 2 and a sink on a bottom of an inner face of a case 1 in contact with the notch. Passing the winding end through the recessed part to lead the winding end to the outside of the case eliminates the need for placing the end along a lower side of the diaphragm because of provision of a space margin, and the winding end may be extracted from a free end of the voice coil. Thus, it is possible to make the voice coil close to the diaphragm while being fitted to a winding axis and to join the voice coil so as to facilitate automated assembling thereby preventing the winding end from contacting the surrounding components because of a narrow space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small loudspeaker used in a mobile communication device such as a portable telephone and other devices.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional loudspeaker of the electrodynamic type. FIG. 3A is a sectional view, FIG.
(A) is AA sectional drawing of (B). A pot-like yoke 2 made of a magnetic material is insert-molded in a plastic case 1, a magnet 3 is fixed to the yoke 2, and a top plate 4 made of a magnetic material is joined to an upper surface of the magnet.
As a result, a magnetic circuit is formed, and a magnetic gap is generated between the outer periphery of the top plate 4 and the upper inner periphery of the short cylindrical portion of the yoke 2.

The diaphragm 6 has a cross section formed into a corrugated shape.
The outer circumference is adhered to the step inside the upper end of the case 1,
The voice coil 5 is fixed to the lower surface of the diaphragm 6. The voice coil 5 is located in a magnetic gap formed by the top plate 4 and the yoke 2. A protector 7 made of light metal or the like is provided so as to cover the diaphragm 6, and its outer periphery is overlapped with the diaphragm 6 and fixed to a step at the upper end of the case 1. The lower surface of the case 1 and the protector 7 are each provided with a plurality of sound emission holes.

[0004] The two winding terminals 9 of the voice coil 5 are:
As shown in FIG. 3 (A), the adhesive is adhered along the lower surface of the diaphragm 6, pulled out from a notch 1 c provided at the upper end of the cylindrical portion of the case 1, and passed through a recess in the side surface of the case 1. 1 underneath. A substrate 8 such as a glass-containing epoxy resin is adhered to the lower surface of the case 1, and two terminal patterns 10 are provided on the substrate 8 as shown in FIG. They are connected by solder 11.
The terminal pattern 10 has a branched shape, and the winding terminal 9 is soldered to one branch, and the other branch is used for connection when this speaker is incorporated in a device.

The operation of this speaker is well known.
When a signal current is applied to the voice coil 5, the voice coil 5 and the diaphragm 6 integrated therewith vibrate to generate sound due to the electromagnetic action of the current and the magnetic flux generated in the magnetic gap.

[0006]

In the prior art shown in FIG. 3, the two winding terminals 9 of the voice coil 5 are pulled out as described above, but they are adhered along the lower surface of the diaphragm 6. I have. As shown in FIG. 3A, on the periphery of the voice coil 5 and on the lower surface of the diaphragm 6, the inner periphery and the upper end of the cylindrical portion of the yoke 2,
Since the inner bottom surface of the case 1 and the like are close to each other, in order to guide the winding terminal 9 to the outside without touching them, the winding terminal 9 may be brought close to the lower surface of the diaphragm 6 or may follow the shape of the gap. Must be habitual, and for that purpose Figure 3
As shown in (A), the location where the winding terminal 9 exits from the voice coil 5 needs to be near the joint between the voice coil 5 and the diaphragm 6.

The voice coil 5 is manufactured by winding a conductive wire around a winding shaft which is a jig of a round bar, and the voice coil 5 is fitted on the end of the winding shaft 21 as shown in FIG. State. It is convenient if the voice coil 5 can be adhered to the diaphragm 6 by bringing the voice coil 5 close to the lower surface of the diaphragm 6 as shown in FIG. The position where the winding terminal 9 comes out of the coil main body is not on the tip end side of the winding shaft 21 but on the opposite lower side as shown in FIG.

As described above, since the winding terminal 9 needs to come out from the vicinity of the bonding portion of the voice coil 5 to the diaphragm 6, the voice coil 5 is connected to the winding shaft 21 as shown in FIG. The voice coil 5 must be pulled out from the winding shaft 21 once as shown in FIG. 3C, and then turned upside down as shown by the arrow to join together. No. This requires more labor and increases the number of man-hours in comparison with the case where the voice coil 5 stuck on the winding shaft 21 is brought close to the diaphragm 6 and joined as it is. The present invention solves this problem, and enables the wound voice coil 5 to be immediately transferred from the winding shaft 21 to the diaphragm 6 and adhered thereto.

[0009]

According to the present invention, a notch is provided in a part of the cylindrical portion of the yoke, and a sink is provided at the bottom of the case in contact with the notch. A concave portion through which the line terminal can freely pass is formed. By passing through this recess, the winding terminal can be guided to the outside of the case in a spacious space unlike the conventional case, and the lead wire comes out from the free end of the coil instead of the joint of the voice coil to the diaphragm This also eliminates the problem, and eliminates the need to join the winding ends along the lower surface of the diaphragm.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. For convenience, the same reference numerals are used for the same kind of parts and portions including the above description. 1A and 1B show an embodiment of a microspeaker according to the present invention, wherein FIG. 1A is a top view, FIG. 1B is a sectional view taken along line BB of FIG. 1A, and FIG. 1C is a sectional view taken along line CC of FIG. In FIGS. 7A and 7C, the protector 7 and the diaphragm 6 shown in FIG.
Since the basic structure of the speaker is the same as that of the conventional example shown in FIG. 3, the characteristic features of the present invention will be described.

In this embodiment, a part of the cylindrical portion of the yoke 2 is notched. In FIG. 3A, the width of the notch is denoted by b, and the bottom surface of the case 1 that is in contact with the notch is also sunk with the same width and depth, thereby forming a concave portion 1d as a whole. The concave portion 1 d forms a space extending from the outer periphery of the magnet 3 and the top plate 4 to the outer periphery of the case 1.

As shown in FIGS. 1A and 1B, the recess 1
d from the voice coil 5 to the case 1
3, there is sufficient space unlike the conventional example of FIG. 3, so that the winding terminal 9 does not have to be brought close to the lower surface of the diaphragm 6 as in the conventional example, and is free in the recess 1d. Can be routed to Conventionally, even if the winding terminal 9 is arranged along the lower surface of the diaphragm 6, the space near the winding terminal 9 is small.
May touch the upper end of the yoke 2 or the bottom of the case 1 to generate abnormal noise or disconnection, but in the present invention, such a concern is eliminated.

The position where the winding terminal 9 comes out of the voice coil 5 can be at the lower end of the coil as shown in FIG. 1B, so that the voice coil 5 is wound up as shown in FIG. The voice coil 5 that has been fitted into the end of the winding shaft 21 may be joined as it is to the lower surface of the diaphragm 6 as it is, and the voice coil 5 is removed from the winding shaft 21, turned over, and then joined to the diaphragm 6 as in the related art. The workability is significantly improved as compared with the case of.

FIG. 2 is a sectional view of another embodiment of the present invention. While the case 1 of the embodiment of FIG. 1 has a unitary structure, the case of FIG.
(23) It is divided into two bodies. Case A (22) has a magnetic circuit unit such as magnet 3 and yoke 2 mounted thereon.
(23) is a ring shape having a shelf 23b on the inner periphery of a short cylindrical portion 23a, in which the diaphragm 6 and the diaphragm components of the voice coil 5 and the protector 7 are joined. Then, the two cases are joined with an adhesive or ultrasonic welding. Here, as in the previous embodiment, the yoke 2 is notched, and a recess is formed in the bottom surface of the case A (22) to form a concave portion 22d.
Is led out of the notch 23c of the case B (23) through the concave portion 22d without being along the lower surface of the diaphragm 6.

In the embodiment shown in FIG. 1, the diaphragm 6 is
It is necessary to fix the voice coil 5 before joining to the diaphragm, and fixing the voice coil 5 to the diaphragm 6 having low rigidity by itself is not always an easy operation, but the voice coil 5 is divided into two as shown in FIG. If the magnetic circuit section and the diaphragm section are mounted on the case, the voice coil 5 may be joined with the diaphragm 6 being joined to the case B (23) with the outer periphery being reinforced, and the assembly is automated. Becomes easier.

In the embodiment shown in FIGS. 1 and 2, the recesses 1d and 22d formed by the notch of the yoke 2 and the sinking of the inside of the case are provided only on the left side of the figure. Can also be provided. In this case, the shapes of the components are balanced, and the electromagnetic action of the magnetic flux and the current of the coil is balanced, so that the operation is more stable.

[0017]

According to the present invention, since the space inside the case of the micro-speaker can be made extra, the freedom of the winding terminal can be increased, and the winding terminal can be connected to the diaphragm of the voice coil as in the prior art. There is no restriction that it must come out of the joint or adhere along the lower surface of the diaphragm, which facilitates automation of assembly. Since the space around the winding terminal is increased, there is no possibility that the winding terminal hits the yoke or the inner surface of the case, thereby generating abnormal noise or breaking. In this way, a compact, high-performance, and inexpensive speaker is realized.

[Brief description of the drawings]

FIG. 1A is a top view of an embodiment of the present invention, and FIG.
3A is a cross-sectional view taken along line BB of FIG. 3A, and FIG. 3C is a cross-sectional view taken along line CC of FIG.

FIG. 2 is a cross-sectional view of another embodiment of the present invention.

3A is a cross-sectional view, FIG. 3B is a bottom view, and FIG. 3A is a cross-sectional view taken along line AA of FIG.

FIG. 4 is a diagram showing a relationship between a voice coil and a diaphragm after winding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 1d, 22d recessed part 2 Yoke 3 Magnet 4 Top plate 5 Voice coil 6 Diaphragm 7 Protector 8 Substrate 9 Winding terminal 21 Winding axis 22 Case A 23 Case B

Claims (3)

[Claims] 1. A speaker comprising a permanent magnet, a bottomed short cylindrical yoke, a voice coil, a diaphragm, a protector and the like attached to a case, wherein a notch is provided in a cylindrical portion of the yoke, and a case in contact with the notch. A microspeaker characterized by forming a recess from the periphery of the magnet to the outer periphery of the case by providing a depression at the bottom of the case, and guiding the winding terminal of the voice coil to the outer periphery of the case through the recess. 2. The micro-speaker according to claim 1, wherein the case has one or two members. 3. The loudspeaker according to claim 1, wherein the recess provided in the case is provided at one place or symmetrically on both sides of the center of the micro loudspeaker.