JP2004180256A - Speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin speaker in which a special housing member is not required, thereby reducing the number of parts to reduce costs. <P>SOLUTION: When an audio signal is given, a coil 14 and a magnet 16 are relatively oscillated and, a part of an oscillating member 13 having a magnetic driving part 10 is locally oscillated. Local oscillation is propagated to the entire oscillation member 13 and a sound is generated from the oscillation member 13. It is not necessary to conventionally oscillate an entire oscillation film with the large amplitude of the coil, such that the stroke quantity of the coil is reduced and a speaker 11 thinned. Further, the speaker 11 may be arranged in a housing 12 of a mobile telephone set or the like and a housing exclusive for the speaker is not required, thereby reducing the number of parts to reduce the costs. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a speaker for reception mounted on a mobile phone or the like, and more particularly to a speaker that can be reduced in thickness, and has a reduced number of parts and a reduced cost.
[0002]
[Prior art]
FIG. 3 is a sectional view showing the structure of a conventional speaker.
[0003]
In the loudspeaker 1 shown in FIG. 3, a vibrating film 3 is stretched on an upper edge portion of a housing 2, and a coil 4 is provided on a lower surface of the vibrating film 3.
[0004]
A cup-shaped external yoke 5 is fixed to the bottom 2a of the housing 2 with the opening 5a facing the Z1 direction in the figure. A magnet 6 is fixed to the center of the outer yoke 5. The magnet 6 is formed in a substantially columnar shape. For example, the upper portion in the Z1 direction is magnetized to the N pole, and the lower portion in the Z2 direction is magnetized to the S pole. A disk-shaped internal yoke 7 is fixed to the upper part of the magnet 6 in the figure, and the coil 4 is arranged in a gap G provided between an edge of the internal yoke 7 and an inner edge of the external yoke 5. Have been. In the speaker 1, a magnetic path is formed by the pole of the magnet 6, the inner yoke, the gap G, the outer yoke, and the S pole of the magnet 6.
[0005]
The coil 4, the outer yoke 5, the magnet 6, and the inner yoke 7 form a magnetic driving unit. When an audio signal is applied to the coil 4, the current of the audio signal and the magnetic flux passing through the gap G cause a fleming. An electromagnetic force corresponding to the left hand acts, and the coil 4 is vibrated in the Z1 and Z2 directions shown. At this time, the vibration film 3 is also vibrated in the vertical direction, and a sound corresponding to the audio signal is emitted from the vibration film 3.
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. H10-178697 [Patent Document 2]
JP 2000-29569 A [Patent Document 3]
Japanese Patent Application Laid-Open No. 2000-341792 [Patent Document 4]
JP 2001-212496 A
[Problems to be solved by the invention]
However, the above-mentioned conventional speaker 1 is a so-called moving magnet type speaker in which the yoke side is fixed to the housing 2 and the coil 4 vibrates together with the vibration film 3. Since the sound is generated with the amplitude of the coil 4, it is necessary to increase the stroke amount of the coil 4. For this reason, it is necessary to form the height dimension of the housing 2 high and secure the stroke amount required by the coil 4, so that there is a problem that it is difficult to make the speaker 1 thin.
[0008]
In addition, as described above, the conventional speaker 1 has a configuration in which one magnetic drive unit is formed in a state where the magnetic drive unit is dispersed in both the housing 2 and the diaphragm 3. Therefore, the dedicated housing 2 is indispensable. Therefore, it was not targeted for reduction of the number of parts.
[0009]
In addition, most of conventional speakers for mobile phones output monaural sound. Further, in order to achieve stereo, it is usually necessary to use two or more diaphragms, but it has been difficult to provide a plurality of diaphragms in a narrow space.
[0010]
An object of the present invention is to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a speaker capable of further promoting a reduction in thickness of an electromagnetic speaker.
[0011]
Another object of the present invention is to provide a speaker in which the magnetic drive unit is disposed on the vibration member side, thereby eliminating the need for a dedicated housing, thereby reducing the number of parts and cost. .
[0012]
Another object of the present invention is to provide a speaker that can exhibit a stereo effect with one vibration member.
[0013]
[Means for Solving the Problems]
The present invention provides a magnetic drive unit including a cylindrical coil to which an audio signal is given, a magnet for generating a magnetic flux, and a yoke member for guiding the magnetic flux generated by the magnet to the coil, and the magnetic drive unit generates the magnetic drive unit. A vibrating member that generates sound by receiving an electromagnetic force,
The coil is fixed to a vibration member, and a magnet to which the yoke member is fixed is provided inside the coil.
[0014]
In the loudspeaker of the present invention, the magnetic drive unit can be provided on the lower surface of the vibration member, so that a dedicated housing can be omitted.
[0015]
In addition, since relative vibration between the magnet and the coil occurs locally, and then spreads over the entire vibrating member, sound is generated. Therefore, it is necessary to vibrate the coil with a large stroke in order to vibrate the vibrating membrane as in the past. Absent. Therefore, it is possible to promote the reduction in thickness of the entire speaker.
[0016]
In the above, it is preferable that the thickness of the vibrating member is 100 μm or more and 1 mm or less. For example, the vibrating member can be formed of acrylic or polycarbonate.
[0017]
When the entire thickness of the vibrating member is as thick as about 1 mm and becomes hard, it is preferable that an elastic member is provided between the vibrating member and the magnet.
[0018]
With the above configuration, a loud sound can be generated even when the plate thickness is increased.
[0019]
Alternatively, the thickness of the vibrating member at the portion where the magnetic drive unit is provided may be locally thinner than the thickness of other portions of the vibrating member.
[0020]
Even with such a configuration, it is possible to generate a loud sound.
Further, it is preferable that the magnetic drive unit is provided at a position other than a center portion of the vibration member, and in this case, the vibration member is provided on another electronic device on which a display device is mounted. And can be used as a protective member of the display device.
[0021]
In addition, it is preferable that the magnetic drive unit is provided at at least two positions around the vibrating member, and in a small electronic device such as a mobile phone, the magnetic drive unit is It is provided at each of the positions of both ends of the display device.
[0022]
In this case, an audio signal corresponding to each channel is provided to each magnetic drive unit from a stereo sound source of a plurality of channels.
[0023]
According to the above configuration, it is possible to generate a stereo sound excellent in a sense of reality from one vibration member, and it is possible to increase the added value of the mobile phone.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a partial sectional view showing a structure of a speaker as an embodiment of the present invention, and FIG. 2 is a partial sectional view showing a structure of a speaker as another embodiment of the present invention.
[0025]
FIG. 1 shows a speaker 11 provided in a mobile phone, for example, and reference numeral 12 denotes a housing of the mobile phone.
[0026]
A thin plate-shaped vibration member 13 is provided at an opening end of the housing 12 on the Z1 side in the drawing. The vibrating member 13 is formed of a transparent plate material made of, for example, acrylic, polycarbonate, or the like, and has a plate thickness of 100 μm or more and 1 mm or less.
[0027]
On the lower surface of the vibration member 13, a magnetic drive unit 10 including the coil 14, the yoke member 15, and the magnet 16 is provided at one end of the housing 12 at a position other than the center of the vibration member 13. ing.
[0028]
The coil 14 has a cylindrical shape and is fixed to the lower surface of the vibration member 13. A substantially cylindrical magnet 16 is provided inside the coil 14, and a disc-shaped yoke member 15 is fixed to the lower surface of the magnet 16. However, the speaker 11 shown in FIG. 1 uses a relatively thick and hard vibration member 13 having a plate thickness t of 1 mm, and a rubber or foam material is formed between the vibration member 13 and the magnet 16. Provided elastic member 18 is provided.
[0029]
The magnet 16 of the magnetic drive unit 10 is, for example, magnetized on its upper side with an S pole and its lower side with an N pole. The magnetic flux φ generated by the magnet 16 is guided by the yoke member 15, interlinks the current flowing from the edge of the yoke member 15 to the coil 14, reaches the outside of the coil 14, and bends upward (Z1 direction) in the figure. Once it reaches the outside of the vibration member 13. Further, the magnetic flux φ moves toward the center of the coil 14 along the surface of the vibration member 13, bends downward (Z2 direction) above the head of the elastic member 18, enters the inside of the vibration member 13 again, and A magnetic path is formed so as to pass through to the S pole of the magnet 16.
[0030]
A liquid crystal display device 20 is provided in another part in the housing 12.
The liquid crystal display device 20 has a diffusion member 22 and an LED 23 functioning as a backlight on a substrate 21. A diffusion sheet 24 is provided on the diffusion member 22, and a liquid crystal display panel 25 is provided thereon. Further, the vibrating member 13 is disposed above the liquid crystal display panel 25. That is, the vibration member 13 also functions as a protection member for protecting the surface of the liquid crystal display panel 25 from scratches and the like.
[0031]
In the magnetic drive unit 10 of the speaker 11, when an audio signal is externally applied to the coil 14, an electromagnetic force according to Fleming's left-hand rule acts due to the current of the audio signal and the magnetic flux φ interlinking the coil 14. Then, the coil 14 and the magnet 16 are relatively vibrated in the vertical direction (Z1 and Z2 directions in the drawing).
[0032]
The vibration due to the electromagnetic force is locally generated in a portion of the vibration member 13 where the magnetic drive unit 10 is provided, and the local vibration is transmitted to the entire vibration member 13, and thereby the vibration member 13 A sound corresponding to the audio signal is generated from the entire area of the thirteen.
[0033]
Here, as shown in FIG. 1, when the thickness t of the vibration member 13 is relatively thick and hard, such as 1 mm, an elastic member 18 is provided between the vibration member 13 and the magnet 16. In addition, since the relative vibration between the coil 14 and the magnet 16 can be increased, it is possible to generate a larger sound from the vibration member 13.
[0034]
If the thickness t of the vibrating member 13 in the portion where the magnetic drive unit 10 is provided is locally thinner than the portion where the other magnetic drive unit 10 is not provided, the magnetic drive Since the vibration of the portion where the portion 10 is provided can be increased, the elastic member 18 can be eliminated.
[0035]
On the other hand, when the plate thickness t of the entire vibration member 13 is 100 μm or less, the vibration member 13 becomes soft and it is difficult to provide the magnetic drive unit 10. Is too hard to transmit vibrations, and it is difficult to secure a audible sound volume. Therefore, the thickness t of the vibration member 13 is preferably in the range of 100 μm or more and 1 mm or less.
[0036]
In the speaker 11, the sound is generated by the relative vibration of the coil 14 and the magnet 16 provided on the vibration member 13, and the locally generated vibration is transmitted to the entire area of the vibration member 13 to listen to the sound. Therefore, there is no need to vibrate the entire vibrating membrane by vibrating the coil largely as in the related art. Therefore, the stroke amount of the coil can be reduced, and the speaker can be reduced in thickness.
[0037]
In the liquid crystal display device 20, the light emitted from the LED 23 enters the inside of the diffusion member 22 and is directed upward in the figure by an inclined surface 22 a provided on the lower surface of the diffusion member 22. Light directed in the illustrated Z1 direction is diffused in the diffusion sheet 24, and uniformly illuminates the entire lower surface of the liquid crystal display panel 25. Characters and the like are displayed on the surface of the liquid crystal display panel 25. Since these characters are brightly illuminated by the diffused light, the characters displayed on the liquid crystal display panel 25 can be easily visually recognized from above the vibration member 13. It becomes possible.
[0038]
As described above, in the speaker 11 of the present invention, the protection member that protects the surface of the liquid crystal display panel 25 can be used as the vibration member 13, and the speaker is provided by providing the magnetic drive unit 10 at the end of the vibration member 13. Since it can be configured, it is not necessary to configure the speaker in a dedicated housing as in the related art. Therefore, since the housing member can be dispensed with, the number of parts can be reduced and the cost can be reduced.
[0039]
Next, a speaker shown in FIG. 2 will be described as another embodiment.
The speaker 31 shown in FIG. 2 has basically the same structure as the speaker 11 shown in FIG. However, the speaker 31 is different from the speaker 11 in that magnetic driving units 10A and 10B are provided at both ends of the housing 12 in the X direction, that is, both ends of the liquid crystal display device 20, respectively.
[0040]
In the speaker 31, an audio signal corresponding to one channel of the two-channel stereo sound source is provided to the magnetic drive unit 10A, and an audio signal corresponding to the other channel is provided to the magnetic drive unit 10B. At this time, the vibration member 13 vibrates according to both the audio signal of the one channel and the audio signal of the other channel. Therefore, although the vibration members 13 that vibrate in accordance with the audio signals of the individual channels are not provided individually, a stereo effect superior in realism can be obtained as compared with the case of the speaker 11 (monaural sound). It is possible. Therefore, stereo sound can be easily enjoyed.
[0041]
In the embodiment shown in FIG. 2, the case where two magnetic drive units 10 are provided in the housing has been described. However, the present invention is not limited to this, and three or four magnetic drive units 10 are provided. By providing a plurality of..., A multi-channel stereo sound may be generated. In this case, each magnetic drive unit 10 is disposed at two or more positions around the vibrating member 13 and requires a stereo sound source having a plurality of channels. From the stereo sound source of the channel, an audio signal corresponding to each channel is provided.
[0042]
Further, the speaker is not limited to being mounted on a mobile phone, but may be mounted on another electronic device.
[0043]
【The invention's effect】
As described above, according to the present invention, the speaker can be reduced in thickness.
[0044]
In addition, since the housing member can be omitted, the number of parts and the cost can be reduced.
[0045]
Further, the vibration member of the speaker can be used as a protection member for the display member.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view showing a structure of a speaker according to an embodiment of the present invention;
FIG. 2 is a partial cross-sectional view showing a structure of a speaker according to another embodiment of the present invention;
FIG. 3 is a cross-sectional view showing the structure of a conventional speaker.
[Explanation of symbols]
10, 10A, 10B Magnetic drive unit 12 Housing 11, 31 Speaker 13 Vibration member 14 Coil 15 Yoke member 16 Magnet 18 Elastic member 20 Liquid crystal display device 21 Substrate 22 Diffusion member 23 LED
24 Diffusion sheet 25 Liquid crystal display panel

Claims (10)

A magnetic drive unit including a cylindrical coil to which an audio signal is applied, a magnet for generating a magnetic flux, and a yoke member for guiding the magnetic flux generated by the magnet to the coil; and an electromagnetic force generated by the magnetic drive unit. A vibration member that sounds
A speaker, wherein the coil is fixed to a vibration member, and a magnet to which the yoke member is fixed is provided inside the coil. The speaker according to claim 1, wherein a thickness of the vibration member is 100 μm or more and 1 mm or less. The speaker according to claim 1, wherein the vibrating member is formed of acrylic or polycarbonate. The speaker according to any one of claims 1 to 3, wherein an elastic member is provided between the vibration member and the magnet. 4. The vibration member according to claim 1, wherein a thickness of the vibration member at a portion where the magnetic driving portion is provided is locally thinner than a thickness of another portion of the vibration member. 5. Speaker. The speaker according to any one of claims 1 to 5, wherein the magnetic drive unit is provided at a position other than a center portion of the vibration member. The speaker according to any one of claims 1 to 6, wherein the vibration member is provided on another electronic device on which a display device is mounted, and is used as a protection member for the display device. The speaker according to any one of claims 1 to 7, wherein the magnetic drive unit is provided at at least two positions around the vibration member. 9. The speaker according to claim 7, wherein the magnetic drive units are provided at both ends of the display device. 10. 10. The speaker according to claim 8, wherein an audio signal corresponding to each channel is provided to each magnetic drive unit from a stereo sound source of a plurality of channels.

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