JP2986250B2 - Speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic speaker.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for a speaker capable of reproducing a bass range without distortion in response to digitization of an electric signal. Here, a conventional speaker will be described with reference to the drawings.

FIG. 2 is a cross-sectional view of the structure of a conventional loudspeaker. 1 is a plate having a yoke on the side surface, 2 is a magnet fixed to the plate 1, 3 is a center pole fixed to the upper surface of the magnet 2, 4 is A voice coil held in a magnetic gap formed by the inner circumference of the yoke portion of the plate 1 and the outer circumference of the center pole 3; 5, a bobbin of the voice coil 4; 6, a diaphragm fixed to the tip of the voice coil bobbin 5; Is a damper fixed to the outer peripheral portion of the voice coil bobbin 5, 8 is an edge provided on the outer peripheral portion of the diaphragm, 9 is a magnetic circuit fixed to the outer periphery of the diaphragm 6, and includes a plate 1, a magnet 2, and a center pole 3. Is a frame that holds.

In the above-described configuration, when an electric signal is applied to the voice coil 4, the diaphragm 6 supported by the damper 7 and the edge 8 vibrates up and down to reproduce the electric signal as sound in space.

[0005]

However, in such a conventional loudspeaker, the stiffness of the damper 7 and the edge 8 which are the supporting members of the diaphragm is reduced to reproduce the low-frequency range, and the stiffness is reduced as much as possible to minimize the resonance. It is necessary to lower the frequency, but when the supporting force is softened, when a large electric input is applied to the voice coil 4, the amplitude of the diaphragm 6 increases, and the bottom surface of the voice coil 4 collides with the top surface of the plate 1 and the voice coil 4 is damaged or the damper 7
Also, there is a fear that the member of the edge 8 may be damaged by an excessive amplitude exceeding the tensile strength. Therefore, in order to dampen the amplitude of the diaphragm 6 at the time of a large input, it is necessary to increase the stiffness of the damper 7 and the edge 8 to have a spring force that overcomes the driving force generated by the voice coil 4.

However, if the damper 7 and the edge 8 are hardened as described above in order to obtain such a strong spring force, the linearity of the support is deteriorated, and this is a major factor in generating distortion in a low frequency range. I was

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional loudspeaker, which prevents a voice coil, a damper, and an edge from being damaged at a large input, and reduces a non-linear distortion of a diaphragm support in a low frequency range. It is intended to realize a speaker with a high level of power.

[0008]

In order to achieve the above object, the present invention provides a center pole, a magnet fixed to upper and lower surfaces of the center pole and magnetized in opposite directions to each other, and upper and lower surfaces of the magnet. An upper and lower plate fixed to the center pole, a magnet and a cylindrical yoke which opposes the outer and inner peripheral surfaces of the plate to form a magnetic gap, and which is held in a magnetic gap between the center pole and the yoke. A speaker including a voice coil.

[0009]

According to the present invention, since the two magnets are magnetized in opposite directions to each other, the magnetic flux direction of the magnetic gap between the center pole and the yoke and the magnetic flux direction of the magnetic gap between the upper and lower plates and the yoke are opposite. Orientation. As a result, the voice coil held in the magnetic gap between the center pole and the yoke moves into the magnetic gap between the center pole and the yoke at the time of large amplitude, and the braking force in the opposite direction to the force received until then. Receive.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the structure of a speaker according to an embodiment of the present invention. In the figure, 10 is a center pole, 11 and 12 are fixed to the upper and lower surfaces of the center pole 10 and are magnetized so that they are opposite to each other, and 13 and 14 are fixed to upper and lower surfaces of the magnets 11 and 12, respectively. Plate, 15 is the center pole 10,
A cylindrical yoke provided on the outer periphery of the plates 13 and 14,
16 is a voice coil held in a magnetic gap between the center pole 10 and the yoke 15, 17 is a voice coil bobbin, 18 is a diaphragm fixed to the tip of the voice coil bobbin 17, and 19 is a damper fixed to the outer periphery of the voice coil bobbin 17. Reference numeral 20 denotes an edge provided on the outer periphery of the diaphragm 18, reference numeral 21 denotes a frame to which the outer peripheries of the damper 19 and the edge 20 are fixed and the yoke 15 and the plate 14 are fixed and held.
The magnetic gap between 3, 3 and yoke 15 is maintained with high precision.

The operation of the embodiment will be described below.

The voice coil 16 is held in a magnetic gap between the center pole 10 and the yoke 15 by a damper 19 and an edge 20 which are supports for the diaphragm 18.
When an electric input is applied thereto, it vibrates up and down, and vibrates the diaphragm 18 connected by the voice coil bobbin 20 to reproduce sound, which is almost the same operation as the conventional example.

The major difference from the conventional example is that, in addition to the magnetic gap between the center pole 10 and the yoke 15, the plates 13, 14 and the yoke 15 are located above and below the magnetic gap.
Is provided with two magnetic gaps composed of In FIG. 1, the flows of magnetic flux in the respective magnetic gaps are indicated by a and b. 1
The direction of the magnetic flux in the magnetic gap between the third and fourth yokes 15 is reversed. Therefore, the direction of the driving force received by the voice coil 16 is opposite in the magnetic gap between the center pole 10 and the yoke 15 and in the magnetic gap between the plates 13 and 14 and the yoke 15. Therefore, the voice coil 16
When a large electric input is applied, the voice coil 16 protrudes from the magnetic gap between the center pole 10 and the yoke 15, and the plate 13 or the plate 14 and the yoke 15
And the voice coil 16 receives a force in a direction to dampen its movement.

[0015]

As described above, according to the present invention, even when a large input is applied to the voice coil and the diaphragm attempts to have a large amplitude, this movement is electrically damped, so that the damper and the edge supporting the diaphragm are supported. It is no longer necessary to brake the movement by the mechanical spring force of. This makes it possible to reduce the stiffness of the damper and the edge to weaken the spring force of the support, thereby reducing distortion in the low-frequency range due to the non-linearity of the support. Further, reducing the stiffness of the support lowers the bass reproduction limit frequency of the loudspeaker, thereby expanding the bass reproduction band as compared with the conventional example.

Further, the problem that the bottom surface of the voice coil, which occurred in the prior art, is broken by colliding with the upper surface of the plate is solved by providing a magnetic gap between the plate and the yoke and improving the structure of the voice coil. It has the advantage that it can be eliminated by action.

[Brief description of the drawings]

FIG. 1 is a structural sectional view of a speaker according to an embodiment of the present invention.

FIG. 2 is a structural sectional view of a conventional speaker.

[Explanation of symbols]

 Reference Signs List 10 Center pole 11, 12 Magnet 13, 14 Plate 15 Yoke 16 Voice coil 19 Damper 20 Edge

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04R 9/00-9/10

Claims (2)

(57) [Claims] 1. A center pole, a magnet fixed to upper and lower surfaces of the center pole and magnetized in opposite directions to each other, upper and lower plates fixed to upper and lower surfaces of the magnet, respectively, A speaker comprising: a cylindrical yoke that opposes an outer periphery and an inner periphery to form a magnetic gap; and a voice coil held in a magnetic gap between the center pole and the yoke. 2. The loudspeaker according to claim 1, wherein the magnetic gap of the magnetic circuit including the plate and the yoke is constituted by a frame that contacts the bottom surface of the plate and the outer peripheral surface of the yoke.