JP4811284B2 - Speaker - Google Patents

Description

  The present invention relates to a speaker used in various audio equipment and information communication equipment.

  At present, cellular phones and flat-screen TVs are becoming more and more popular, and there is a demand for thinner speakers that are built into such appliances.

  The conventional speaker shown in FIG. 3 includes a frame 1, a lower plate 3 disposed at the center of the frame 1 and having a center pole 3 a, a magnet 5 disposed on an outer peripheral portion of the lower plate 3, The magnetic coil 7 formed by the lower plate 3 was provided with a voice coil 9 movably arranged in the vertical direction, and a diaphragm 11 supporting the voice coil 9 and having an outer peripheral end connected to the frame 1. .

For example, Patent Document 1 is known as a prior art document relating to the invention of this application.
JP 2005-51283 A

  If the above-described speaker is to be thinned, the most effective means is to reduce the size of the magnet 5 and reduce the overall height of the magnet 5.

  Certainly, as described above, if the magnet 5 is miniaturized, the overall height of the speaker can be lowered, and the thickness can be reduced.

  However, if the magnet 5 is downsized, there are problems as shown below.

  That is, since the magnetic force is proportional to the size of the magnet, if the magnet 5 is downsized to reduce the thickness, the magnetic force of the magnet 5 is reduced, and as a result, a sufficiently satisfactory audio output can be obtained from the speaker. There was a problem that it was not possible.

  Accordingly, an object of the present invention is to reduce the thickness of a speaker without reducing the sound output.

In order to achieve this object, the present invention provides a first metal yoke having a dish-like shape, a first magnet disposed on the inner bottom of the first yoke, and the first A second magnet disposed in an oblique direction or a substantially horizontal direction with respect to the magnet, and the second magnet is supported by the lower inner periphery and connected to the upper outer periphery of the first yoke, and has a hole in the center. A metal second yoke, a voice coil disposed so as to be vertically movable with respect to a magnetic gap formed between the first magnet and the second magnet, and the voice coil on the lower surface A diaphragm having an outer peripheral end connected to the second yoke, and a cross-section of the second yoke having a substantially crank-shaped central portion , and the diaphragm and the second yoke Position of the connecting part with the yoke It is obtained by the configuration the second magnet is arranged the same height or lower position than the position.

  With the above configuration, the speaker can be thinned without downsizing the magnet. This is because the two magnets of the first magnet and the second magnet are used, and the connecting portion of the diaphragm and the second yoke is positioned at substantially the same height as the second magnet, This is because the top portion is prevented from protruding upward.

  Hereinafter, Embodiment 1 of the present invention will be described with reference to FIG.

  First, the configuration in Embodiment 1 of the present invention will be described below.

  The first yoke 13 has a dish shape with a U-shaped cross section. As will be described later, the first yoke 13 is made of metal so as to be a component of the magnetic circuit body 25.

  The first magnet 15 has a disk shape and is arranged at the center of the inner bottom of the first yoke 13, and has an N pole at the top and an S pole at the bottom as shown in FIG. . Further, a metal upper plate 17 is disposed on the first magnet 15, and the upper plate 17 also constitutes a part of the magnetic circuit body 25.

  The second magnet 19 has a donut shape and is disposed obliquely upward and to the left and right of the first magnet 15. Like the first magnet 15, the second magnet 19 has an N pole at the top and an S pole at the bottom. is doing. Similar to the first magnet 15, a metal lower plate 21 is provided below the second magnet 19, and the lower plate 21 also constitutes a part of the magnetic circuit body 25. The upper portion of the second magnet 19 is connected to and supported by the metal second yoke 23. The cross section of the second yoke 23 has a substantially crank-like shape with a bent central portion as shown in FIG. 1, and as a result, the connection between the second yoke 23 and the first yoke 13 is achieved. The portion is located at substantially the same height as the bottom surface of the second magnet 19. The second yoke 23 is also made of metal and is a component of the magnetic circuit body 25.

  The magnetic circuit body 25 includes a first yoke 13, a second yoke 23, a first magnet 15, a second magnet 19, an upper plate 17 and a lower plate 21. In this magnetic circuit body 25, the magnetic flux emitted from the N pole of the first magnet 15 is directed to the lower plate 21 via the upper plate 17, travels in a substantially horizontal direction while passing through the voice coil 29, and further the lower plate The magnetic flux that has reached 21 takes a path to enter the south pole of the second magnet 19. Thereafter, the magnetic flux emitted from the N pole of the second magnet 19 passes through the second yoke 23 and the first yoke 13 in this order, and then reaches the S pole of the first magnet 15. Therefore, as a result, a magnetic gap 27 is formed from the upper plate 17 to the lower plate 21.

  The voice coil 29 is movably inserted into the magnetic gap 27. The voice coil 29 is configured by winding a copper wire around a cylindrical bobbin 30, and its upper end is connected to the lower surface of the diaphragm 31.

  The diaphragm 31 is made of resin, and both the central portion 31a and both end portions 31b have curved shapes. The diaphragm 31 vibrates to generate sound from the speaker. Further, the outer peripheral end portion of the diaphragm 31 is connected to the vicinity of the outer peripheral end portion of the second yoke 23, and the connecting portion 33 is arranged outside the outer periphery of the first yoke 13 and the second magnet 19. It is located at almost the same height.

  Next, the operation and effect of the speaker in Embodiment 1 of the present invention will be described below.

  When an electrical signal with an audio signal added is applied to the voice coil 29, it reacts with the magnetic field in the magnetic gap 27 formed by the magnetic circuit body 25, and a driving force is generated in the voice coil 29 in the vertical direction in accordance with Fleming's left hand rule To do. The driving force is transmitted to the diaphragm 31 connected to the voice coil 29, and as a result, the diaphragm 31 vibrates to generate sound. Further, the driving force of the voice coil 29 at this time is proportional to the magnitude of the magnetic force.

  Therefore, if the conventional speaker having the configuration shown in FIG. 3 is thinned and the magnet 5 is reduced in size, the magnetic force emitted from the magnet 5 is weakened, and the driving is performed to sufficiently vibrate the diaphragm 11. Power could not be gained. That is, in this case, a sufficient sound output cannot be obtained, and it is actually difficult to reduce the thickness of the speaker.

  Therefore, in the first embodiment of the present invention, the speaker can be thinned by adopting the configuration shown in FIG.

  In other words, the two magnets, the first magnet 15 and the second magnet 19, are provided in an oblique direction, and the magnetic force of the first and second magnets 15 and 19 is effectively utilized to sufficiently output sound. In the case where the connecting portion 33 is provided above the magnet 19 by securing the driving force and arranging the connecting portion 33 between the diaphragm 31 and the second yoke 23 at substantially the same height as the second magnet 19. This is because the top portions of both end portions 31b are prevented from protruding upward. As a result, the overall height of the speaker can be reduced without reducing the size of the magnet. In the first embodiment, the connection portion 33 has substantially the same height as the second magnet 19. However, the present invention is not limited to this configuration. Of course, the connection portion 33 is disposed below the second magnet 19. May be. In this case, the speaker can be further thinned. The present invention can also be applied to a loudspeaker having a configuration using the second magnet 19 having polarity in the left-right direction as shown in FIG. In this configuration, the magnetic flux emitted from the first magnet 15 passes through the voice coil 29 via the upper plate 17 and reaches the side plate 35 connected to the S pole side of the second magnet. Even in this configuration, the effects of the present invention can be obtained.

  Further, it is desirable that the diaphragm 31 bends from the connection portion between the vibration plate 31 and the voice coil 29 to the connection portion 33 between the vibration plate 31 and the second yoke 23. With this configuration, it is possible to disperse the stress applied to the diaphragm 31, and it is possible to reduce the possibility that the diaphragm 31 is damaged by the stress generated along with the vibration. In particular, in the present embodiment, it is possible to obtain the effect of preventing the diaphragm 31 and the second yoke 23 from coming into contact with each other and being damaged by bending the diaphragm 31 in addition to the above-described effects.

  Further, in the first embodiment, the connection portion 33 is arranged outside the outer peripheral end of the first yoke 13. This is because if the connecting portion 33 is disposed on the inner side of the outer peripheral end of the first yoke 13, the tops of the both end portions 31b will protrude extremely upward. With such a configuration, the speaker cannot be thinned as a result. Therefore, the connection portion 33 is disposed outside the outer peripheral end of the first yoke 13.

  In the first embodiment, the first yoke 13 and the second yoke 23 are separate members, but they may be integrally formed. In this case, since there is no connection portion between the first yoke 13 and the second yoke 23, the possibility of damage at the connection portion between the first yoke 13 and the second yoke 23 is reduced. can do.

  In Embodiment 1, a speaker having a circular shape is used. However, the present invention is not limited to this, and the present invention is also effective for elliptical and elongated speakers. However, the speaker can be made thinner.

  INDUSTRIAL APPLICABILITY The present invention can reduce the thickness of a speaker having a thin structure without reducing output sound, and is useful for speakers used in various acoustic devices and information communication devices.

Sectional drawing of the speaker in one embodiment of this invention Sectional drawing of the speaker in other embodiment of this invention Cross-sectional view of a conventional speaker

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 1st yoke 15 1st magnet 17 Upper plate 19 2nd magnet 21 Lower plate 23 2nd yoke 25 Magnetic circuit body 27 Magnetic gap 29 Voice coil 30 Bobbin 31 Diaphragm 31a Center part 31b Both ends 33 Connection part 35 Side plate

Claims (4)

A first yoke made of metal having a dish-like shape;
A first magnet disposed on the inner bottom of the first yoke;
A second magnet disposed obliquely or substantially horizontally with respect to the first magnet;
A second yoke made of metal that supports the second magnet on the lower surface side and is connected to the upper outer periphery of the first yoke and has a hole in the center;
A voice coil disposed so as to be movable in a vertical direction with respect to a magnetic gap formed between the first magnet and the second magnet;
The voice coil is supported on the lower surface, and an outer peripheral end portion is provided with a diaphragm connected to the second yoke,
The cross-section of the second yoke has a substantially crank-shaped central portion, and the position of the connecting portion between the diaphragm and the second yoke is the same height as the position where the second magnet is disposed. Or a speaker at a lower position. The speaker according to claim 1, wherein the diaphragm is curved from a connection portion between the diaphragm and the voice coil to a connection portion between the diaphragm and the second yoke. The speaker according to claim 1, wherein a connection portion between the diaphragm and the second yoke is disposed outside an outer peripheral end of the first yoke. The speaker according to claim 1, wherein the first yoke and the second yoke are integrally formed.

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