JPH0617434Y2 - Speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a speaker, and more particularly to a speaker having good linearity at a large amplitude.

(B) Conventional Technology In recent years, audio devices have been digitized as represented by compact disc players and PCM tape recorders. These digital audio devices
A reproduced signal with good frequency characteristics, dynamic range, and S / N ratio can be obtained. Especially, the frequency characteristics are several in the low frequency direction.
It extends flat to Hz, and the dynamic range is much wider than analog record players and tape decks. Therefore, a speaker with high quality having good linearity from small amplitude to large amplitude is required with the digitization of audio devices, but a woofer, which is a speaker for bass reproduction, needs to have large amplitude. However, it is difficult for the current speaker to obtain sufficient linearity up to a large amplitude. In particular, recently, a small stereo set called a minicomputer has become popular. Since the speaker system of the minicomputer is small, a woofer of a diaphragm having a small aperture is naturally used. Therefore, in the woofer of the speaker system of the minicomputer, it was even more difficult to obtain sufficient linearity even when the amplitude was large.

Therefore, in order to solve the above-mentioned drawbacks, a speaker called a motional feedback (MFB) type speaker has been proposed. The MFB type speaker reduces nonlinear distortion by feeding back a voltage proportional to the movement (speed, acceleration or displacement) of the diaphragm to the input side, as described in, for example, Japanese Patent Application Laid-Open No. 60-3298. Good linearity at large amplitude.

(C) Problems to be solved by the invention However, since the MFB type speaker electrically solves the linearity at the time of large amplitude as described above, the center holding of the diaphragm determined by the structure of the edge and the damper is maintained. There is no change in the ability (the ability to support to oscillate correctly in the axial direction), a complicated electric circuit is required, and measures for protecting the speaker are also required, and the electric circuit is faithful to the input signal. It was difficult to design because it was necessary to drive the speaker in the.

The present invention aims to provide a novel speaker made in view of the above points, and particularly devises a method of connecting lead wires for supplying a driving current to a voice coil.

(D) Means for Solving the Problems The present invention is directed to a diaphragm provided with a through hole, and the diaphragms are arranged so as to face each other with the diaphragm sandwiched therebetween, and the diaphragms are driven in opposite phases. First and second magnetic circuits, first and second voice coils wound around bobbins arranged in the magnetic gaps of the first and second magnetic circuits, and a terminal to which an input signal is applied A first lead wire for supplying an input signal applied to the terminal to the first voice coil, and a second lead wire connected to the first lead wire and penetrating a through hole of the diaphragm to the second voice coil. And a second lead wire to be connected.

(E) Operation The present invention responds to an input signal applied to the terminal by providing a through hole in the diaphragm and a lead wire penetrating the through hole and connecting the first and second voice coils. A drive current is supplied to the first and second voice coils.

(F) Embodiment FIG. 1 is a sectional view showing an embodiment of the present invention. ( 1 ) is a first magnetic circuit including a permanent magnet (2), a center pole / bottom (3) and an upper plate (4). , (5) is the first magnetic circuit
A first bobbin elastically supported by the first damper (7) in the magnetic air gap (6) of ( 1 ), (8) a first voice coil wound around the first bobbin (5), ( 9) ) Is a second magnetic circuit composed of a permanent magnet (10), a center pole / bottom (11) and an upper plate (12), and (13) is a magnetic air gap (14) of the second magnetic circuit ( 9 ).
A second bobbin elastically supported by a second damper (15), (16) a second voice coil wound around the second bobbin (13), and (17) a first bobbin (5). A second sub-cone connected to the second bobbin (13), (19) a first sub-cone connected to the first sub-cone, and a second sub-cone connected to the second bobbin (13).
A flat diaphragm supported from both sides by (18), (20) a first frame to which the first magnetic circuit ( 1 ) is attached, and ( 21 ) a first frame to which the second magnetic circuit ( 9 ) is attached. 2 frames, (2
2) is an edge for elastically supporting the flat diaphragm (19) on the first frame (20), and (23) is a terminal fixed to the first frame (20) and to which an input signal is applied. ,
(24) is a first lead wire for supplying the input signal applied to the terminal (23) to the first voice coil (8), and (25) is connected to the first lead wire (24) A second lead wire connected to the second voice coil (16).

By the way, the same first magnetic circuit ( 1 ) and second magnetic circuit ( 9 ) are arranged to face each other across the plane diaphragm (19). Further, the flat diaphragm (19) is provided with a through hole (26) inside the point supported by the first and second sub-cones (17) and (18), and the second lead wire (25) is The first lead wire (24) and the second voice coil (16) are connected through the through hole (26). In this case, the driving currents flowing through the first voice coil (8) and the second voice coil (16) are set in opposite directions to the magnetic fields generated by the first or second magnetic circuit ( 1 ) or ( 9 ), respectively. And the first and second voice coils are configured to drive the planar diaphragm (19) in reverse phase.
The forces applied to the first and second bobbins (5) and (13) are the same when the same drive current is applied to (8) and (16).

The second frame ( 21 ) grips the second magnetic circuit ( 9 ) by the gripping part (21b) extending from a part of the peripheral part (21a) fixed to the baffle plate (27) of the speaker box. Are placed in place.

Now, when an input signal is applied to the terminal (23) of the speaker configured as described above, the input signal is applied to the first lead wire (2).
It is supplied as a drive current to the first voice coil (8) via the cable 4) and is also supplied to the second lead wire (25). The second
The input signal supplied to the lead wire (25) is supplied to the second voice coil (16) as a drive current. Therefore, by the action of the first magnetic circuit ( 1 ), the first voice coil (8) is wound around the first bobbin (5) and the first sub-cone (17) connected to the first bobbin (5). A force according to the input signal is applied and the second voice coil (1) is operated by the action of the second magnetic circuit ( 9 ).
A force corresponding to the input signal is applied to the second bobbin (13) around which 6) is wound and the second sub-cone (18) connected to the second bobbin (13). Here, the first and second voice coils
When the same driving current flows in (8) and (16), the forces generated by the actions of the first and second magnetic circuits ( 1 ) and ( 9 ) are equal in opposite directions, so the first sub-cone (17) When the flat diaphragm (19) is pushed by a predetermined force in the forward arrow A direction, the flat diaphragm (19) is pushed by the second sub-cone (18) by the same force as the pushed force. Pulled in the direction. Therefore, the plane diaphragm (19) is driven (push-pull drive) by the first and second sub-cones (17) and (18) like push-pull amplification in an amplifier circuit, and a sound corresponding to an input signal is generated. It radiates from the opening (21c) of the second frame ( 21 ).

Therefore, the above-mentioned speaker has the first diaphragm on the flat diaphragm (19).
Since the combined force of the forces generated by the second and second magnetic circuits ( 1 ) and ( 9 ) is applied, the magnetic damping is well applied, the sound quality with damping is obtained, and the flat diaphragm (19) is obtained. The transmission loss at the joint surface between the first and second sub-cones (17) and (18), that is, the drive point on the flat diaphragm (19) is improved, and the efficiency is increased. Further, since the flat diaphragm (19) is supported from both sides by the first and second sub-cones (17) and (18), the center holding ability is also excellent.

The speaker shown in FIG. 1 has a support point of the vibration system around the plane diaphragm (19), that is, a connection point between the first bobbin (5) and the first sub-cone (17) and a second bobbin (13). Between the connection point with the second sub-cone (18) and the connection point between one side of the plane diaphragm (19) and the edge (22), the other side of the plane diaphragm (19) and the edge (22) Since the connection points can be made substantially symmetrical, the amplitude of the flat diaphragm (19) can be increased without causing surface wobbling, and the first damper (7) is centered around the flat diaphragm (19). And the second damper (15) are symmetrical,
By the push-pull operation of the flat diaphragm (19), the first
Since diametrically opposite nonlinear distortion components are generated from the second dampers (7) and (15), the nonlinear distortion components are canceled out, and the linearity with respect to displacement is excellent.

Further, the speaker shown in FIG. 1 has a first voice coil (8).
Since the second voice coil (16) and the second voice coil (16) are connected by the second lead wire (25) penetrating the through hole (26) provided in the flat diaphragm (19), this speaker is connected to the baffle plate (27). Attached to the flat lead plate (19) of the second lead wire (25).
A portion located in front of is covered with the second sub-cone (18), and the second lead wire (25) is hidden.

In the case where the diaphragm is directly supported by the bobbin without passing through the sub-cone, the two lead wires are disposed so as to face each other with the second lead wire penetrating the diaphragm and passing through the inside of the bobbin. The second lead wire can be hidden by connecting voice coils arranged in respective magnetic air gaps of the magnetic circuit.

Also, the first speaker uses the same first and second magnetic circuits ( 1 ) and ( 9 ), and the first voice coil (8)
The same input signal flows in the opposite directions to the second voice coil (16) and the second voice coil (16) so as to have opposite phases, and the flat diaphragm (19) is push-pull driven.
And the permanent magnets (2) of the first magnetic circuit ( 1 ) and the permanent magnets (2) of the second magnetic circuit ( 9 ) such that the same input signal flows in the same direction to the second voice coils (8) and (16). The plane diaphragm (19) may be push-pull driven by reversing the polarity of the magnet (10).

FIG. 2 shows a speaker system using the speaker of the present invention. In Figure 2, tweeter for high-pitched sound reproduction (28)
In addition, a general flat speaker is used for the squawker 29 for reproducing the middle sound, and the speaker of the present invention is used for the woofer for reproducing the low sound. The speaker of the present invention is particularly effective because the woofer needs to have a large amplitude. In addition, the speaker of the present invention has a holding part (21) of the second frame (21) holding the second magnetic circuit ( 9 ) in front of the flat diaphragm (19).
Although b) is arranged, the bass has little directivity, and therefore is hardly affected by the grip portion (21b). In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals.

(G) Effect of the Invention As described above, according to the present invention, a speaker having good linearity and excellent center holding ability can be obtained by push-pull driving the diaphragm using the first and second magnetic circuits. And a driving current is supplied to a voice coil arranged in a magnetic gap of a magnetic circuit located in front of the diaphragm by a second lead wire passing through a through hole provided in the diaphragm. Therefore, there is an advantage that the lead wire can be hidden and the appearance can be improved.

[Brief description of drawings]

1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a front view showing a speaker system using the speaker of FIG. Description of main drawing numbers ( 1 ) ... first magnetic circuit, (8) ... first voice coil, ( 9 ) ... second magnetic circuit, (16) ... second voice coil, (17) ... first sub-cone, (18) ... Second sub-cone, (19) ... planar diaphragm, (23) ... terminal, (24) ... first lead wire, (25) ... second lead wire, (26) ... through hole.

Claims (1)

[Scope of utility model registration request] 1. A vibrating plate having a through hole, first and second magnetic circuits which are arranged to face each other across the vibrating plate and drive the vibrating plates in opposite phases to each other. First
The first and second voice coils wound around bobbins arranged in the magnetic gaps of the first and second magnetic circuits, the terminal to which the input signal is applied, and the input signal applied to the terminal, respectively. A first lead wire supplied to the first voice coil, and a second lead wire connected to the first lead wire and penetrating a through hole of the diaphragm and connected to the second voice coil, A speaker, wherein a driving current is supplied to the first and second voice coils by applying an input signal to the terminal.