JP2008259049A - Electromagnetic converter and speaker system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an electromagnetic converter which vibrates with a great amplitude to generate playback sound, and a speaker system which attains improvement of bass playback capability and improvement of output sound pressure level by increasing a playback sound radiation area while suppressing a front projection area and performs excellent acoustic output without generating strong directivity. <P>SOLUTION: A resin or corn paper that is hardly deformed when generating vibration of a greater amplitude than a polyimide film, is used for a diaphragm and a plurality of electromagnetic converters 2, in each of which the relevant diaphragm is supported by a supporting member via a damper that does not transport vibration of the diaphragm to the supporting member, are sequentially provided on the front of a case 3 that is formed in a folding screen shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic transducer for reproducing an audio signal, for example, and a speaker device using the electromagnetic transducer.

The electromagnetic transducer includes a permanent magnet plate on which a multi-pole magnetized pattern of parallel stripes is formed, a vibration film of a resin film disposed so as to face the permanent magnet plate, and a space between the permanent magnet plate and the vibration film. It is comprised by the buffer member arrange | positioned. The multipolar magnetization pattern of the permanent magnet plate is obtained by alternately arranging magnetic poles having different polarities at regular intervals. The vibration film is formed by placing a coil of a meandering conductor pattern on the entire film surface so as to face a so-called magnetized neutral zone that occurs in the gap between different magnetic poles arranged on the permanent magnet plate. It is made to form.
In such a configuration, when an audio signal current flows through the coil of the diaphragm, the multipolar magnetization pattern of the coil and the permanent magnet plate is electromagnetically coupled, and audio vibration is generated in the diaphragm according to Fleming's law (for example, , See Patent Document 1). The permanent magnet plate, the vibration film, and the buffer member are supported by being covered with a frame of the electromagnetic transducer, and are attached to the front surface of the housing or the like of the speaker device.

JP-A-9-331596 (pages 3 to 5, FIGS. 1 and 2)

Since the conventional electromagnetic transducer is configured as described above, the area of the diaphragm is increased when reproducing the bass well with the film-like diaphragm, and in order to improve the sound pressure level. In other words, it is necessary to increase the outer dimensions of the electromagnetic transducer or the like, or to increase the amplitude of the vibrating membrane, and it is inevitable to increase the size of the outer shape. There was a problem that it would end up.
In addition, since the vibrating membrane vibrates in the vertical direction of the membrane surface, the output sound of the electromagnetic transducer has a strong directivity and is used as a high-fidelity speaker device that emits reproduced sound so that good sound can be obtained. There was a problem that it was unsuitable.

  The present invention has been made to solve the above problems, and an electromagnetic transducer capable of generating reproduced sound by vibrating with a large amplitude, and a radiation area of reproduced sound while suppressing a front projection area An object of the present invention is to obtain a loudspeaker device that improves the bass reproduction capability and the output sound pressure level, and produces a good sound output without causing strong directivity.

  The electromagnetic transducer according to the present invention includes a damper that does not transmit vibration of the diaphragm to the support member at the edge of the diaphragm on which the meandering coil pattern is formed, and the diaphragm is supported by the support member via the damper. It is something to be made.

  The speaker device according to the present invention includes a plurality of electromagnetic transducers arranged in a folding screen in front of a casing formed in a folding screen.

According to this invention, since the diaphragm of the electromagnetic transducer is supported by the support member via the damper, it is possible to generate audio reproduction sound without disturbing the vibration of the diaphragm.
In addition, since multiple electromagnetic transducers are arranged in a folding screen, the area to radiate audio playback sound is gained while suppressing the front projection area, improving bass playback capability, improving sound pressure level, and omnidirectional sound output. There is an effect that can be obtained.

An embodiment of the present invention will be described below.
Embodiment 1 FIG.
FIG. 1 is an explanatory diagram showing a configuration of a speaker device according to Embodiment 1 of the present invention. This figure shows a perspective view of the speaker device 1 according to the first embodiment, and shows an aspect in which the casing 3 of the speaker device 1 includes an electromagnetic transducer 2 configured as described later. .
The housing 3 is formed by connecting a plurality of mounting surfaces made of a single flat surface and folding the screen in a folding screen. When one electromagnetic transducer 2 is mounted on each mounting surface, each electromagnetic conversion is performed. The device 2 is configured to emit audio reproduction sound in different directions. The housing 3 illustrated in FIG. 1 is equipped with 12 electromagnetic transducers 2, six so as to emit reproduced sound in the left direction in the figure, and six so as to emit reproduced sound in the right direction. Is arranged. The mounting surface of the housing 3 is formed as a folding screen opened at an angle α as shown in the figure. When the electromagnetic transducers 2 are respectively mounted on the mounting surfaces, two opposing electromagnetic transducers 2 are mounted. Is configured to form an angle α of, for example, 60 ° or more.

FIG. 2 is an exploded perspective view showing the configuration of the electromagnetic transducer according to the first embodiment. This figure shows a schematic configuration of the electromagnetic transducer 2 shown in FIG. 1, in which one vibrating membrane is sandwiched from above and below by two permanent magnet plates. Buffer members 22a and 22b are disposed on both sides of the vibration film 23, and are laminated so as to prevent buffering with the back side permanent magnet plate 21 and the front side permanent magnet plate 24.
The electromagnetic transducer 2 illustrated in FIG. 2 is configured to cover the structure 10 with a support member 11 and a support member 12 that constitute a frame, and to support the structure inside the frame. The structure 10 is formed by laminating a back side permanent magnet plate 21, a buffer member 22a, a vibration film 23, a buffer member 22b, and a front side permanent magnet plate 24. In addition, each member which comprises the structure 10 illustrated here forms the shape of each board | plate surface etc. in the rectangle of the substantially similar magnitude | size.

  The support members 11 and 12 are made of a ferromagnetic material such as an iron plate formed into a box shape by sheet metal processing, and the support member 11 has a rectangular bottom surface and four side wall surfaces, and opens a portion facing the bottom surface. I am letting. Further, the support member 12 has a rectangular upper surface and four side wall surfaces, and opens an opposing portion of the upper surface. The bottom surface of the support member 11 is provided with a plurality of sound radiation holes 11a for emitting the sound generated by the structure 10 to the outside, and the top surface of the support member 12 is also provided with a plurality of similar sound radiation holes 11a. Further, a flange-shaped joint 11b is provided at the periphery of the opening of the support member 11, that is, at the end portions of the four side walls, and a similar joint 12b is also provided at the periphery of the opening of the support member 12. .

The back side permanent magnet plate 21 has a belt-like sintered ferrite magnet on the entire plate surface facing the vibration film 23 when laminated as described above. This magnetized part is formed by arranging S poles and N poles extending in the longitudinal direction of the plate side by side, and magnetizing in parallel stripes in which different polarities are arranged alternately and at regular intervals. A pattern is formed. Hereinafter, this magnetization pattern is referred to as a multipolar magnetization pattern.
Further, on the plate surface of the back side permanent magnet plate 21, when the back side permanent magnet plate 21 is attached to the support member 11, sound emission holes 21 a communicating with the sound emission holes 11 a of the support member 11 are respectively provided. Is provided. The sound radiating hole 21a is constant in a so-called neutral zone that avoids the magnetized portion of the multipolar magnetized pattern, that is, in the gap between the N and S poles of the multipolar magnetized pattern. It is provided with the pitch.
The front-side permanent magnet plate 24 is configured in the same manner as the back-side permanent magnet plate 21 described above, and has a similar multipolar magnetization pattern. Further, sound radiation holes 24 a communicating with the sound radiation holes 12 a of the support member 12 when the back permanent magnet plate 24 is attached to the support member 12 are respectively provided on the front permanent magnet plate 24. Is provided. The sound radiating hole 24a avoids the magnetized portion of the multi-pole magnetized pattern of the front permanent magnet plate 24, that is, is a so-called magnetized that occurs in the gap between the N-pole and the S-pole of the multi-pole magnetized pattern. In the neutral zone at a constant pitch.

The buffer member 22a is disposed between the back side permanent magnet plate 21 having the multipolar magnetization pattern as described above and the vibration film 23.
The diaphragm 23 includes a diaphragm 23a having a low material density, strong against bending, and having an insulating property, and a damper 25 surrounding an edge portion of the diaphragm 23a. The diaphragm 23a is, for example, (ABS) resin or polystyrene (PS) resin obtained by copolymerizing acrylonitrile having a thickness of 1.0 [mm], butadiene and styrene, cone paper having a thickness of 0.5 [mm], or the like. It is constituted by. In addition, you may comprise using the polyimide laminated board which has the thickness of the grade which can reproduce | regenerate low sound satisfactorily. The vibration plate 23a is formed in the same manner as the bottom surface of the support member 11 and the top surface shape of the support member 12, and the plate surface shapes of the back side permanent magnet plate 21 and the front side permanent magnet plate 24. In the example illustrated in FIG. A conductive pattern meandering throughout is formed on the plate surface. In this conductor pattern, the linear portions extending in the longitudinal direction of the diaphragm 23 a are magnetized on the back side permanent magnet plate 21 and the front side permanent magnet plate 24 when the diaphragm 23 is laminated as a part of the structure 10. A meandering coil pattern 23b that acts as an electromagnetic coil when a current flows is formed.

The damper 25 is made of rubber that is easily deformable and has a restoring force, for example, rubber having an appropriate elasticity / hardness, and is formed in a semicircular shape in the longitudinal section of the vibration film 23, and is also a structural body. When 10 is covered with the support member 11 and the support member 12, a portion sandwiched between the joint portion 11a of the support member 11 and the joint portion 12a of the support member 12 is provided. As described above, the damper 25 surrounds the periphery of the diaphragm 23a, or is provided on at least two opposite sides. The diaphragm 23a is in a floating state with respect to the joint portions 11a and 12a. Is supported by the support members 11 and 12. In addition, when the damper 25 is provided on the two edges of the diaphragm 23a as described above, it is arranged / configured so that a portion not provided with the damper 25 is in a free state in which none is in contact. Further, the damper 25 is affixed / fixed to the edge portion of the vibration plate 23a with, for example, an adhesive tape or an adhesive.
In the diaphragm 23, the diaphragm 23a is arranged inside the box shape of the support members 11 and 12, and the outer end portion of the damper 25, that is, the above-described sandwiched portion is joined to the joint portion 11b of the support member 11 and the support member 12. It is configured in a size that can be placed on the portion 12b.

FIG. 3 is a cross-sectional view showing the configuration of the electromagnetic transducer according to the first embodiment. The same reference numerals are used for the same parts as shown in FIG. This figure shows a longitudinal section of the portion of the dashed line AA 'shown in FIG. 1, and shows a state in which the support member 11 and the support member 12 are joined and the structure 10 is supported therein. ing.
The back-side permanent magnet plate 21 is housed in the box-shaped interior of the support member 11 and is attached to the bottom surface of the support-member 11 inside the box-like shape by the magnetic force of the back-side permanent magnet plate 21 itself. At this time, the sound radiating hole 11a and the sound radiating hole 21a are aligned and attached so as to communicate with each other. A buffer member 22 a is placed on the upper surface of the back side permanent magnet plate 21. The vibration film 23 is stacked above the buffer member 21. At this time, the above-described sandwiching portion of the damper 25 is mounted on the joint portion 11 b of the support member 11. The aforementioned semicircular portion of the damper 25 is disposed in the box-like internal space of the support member 11 so that it can freely expand and contract, and the vibration film 23 is mounted on the support member 11 as described above. . Note that the shape of the damper 25 is not limited to the cross-sectional shape curved upward in the drawing shown in FIG.

A buffer member 22 b is placed on the upper side of the vibration film 23. Further, the range of movement of the damper 25 is not limited by the buffer member 22a and the buffer member 22b. Specifically, the buffer member 22a, 22b does not overlap the damper 25, or the damper 25 and the buffer members 22a, 22b are in contact with each other. The buffer member 22a, the vibration film 23, and the buffer member 22b are stacked so as not to cause the damage.
The front-side permanent magnet plate 12 is housed in the box-shaped interior of the support member 12, and is mounted on the upper surface of the support-member 12 inside the box-like shape by the magnetic force of the front-side permanent magnet plate 12 itself. At this time, the sound radiating hole 12a and the sound radiating hole 24a are aligned and attached so as to communicate with each other. The support member 12 on which the front side permanent magnet plate 12 is mounted is joined to the support member 11, and the front side permanent magnet plate 24 is laminated above the buffer member 22b. In addition, a sandwiching portion of the damper 25 is sandwiched between the joint portion 11b and the joint portion 12b by the above-described joint, and the vibration film 23 is supported inside the frame. When joined in this way, the meandering coil pattern 23b of the vibration film 23 is disposed in a neutral zone nz generated between the magnetic poles of the back-side permanent magnet plate 11 and the front-side permanent magnet plate 12, as shown.

Next, the operation will be described.
FIG. 4 is an explanatory diagram showing the operation of the electromagnetic transducer according to the first embodiment. The same parts as those shown in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof is omitted. This figure shows the movement of the damper 25 when the vibrating membrane 23 vibrates inside the frame in which the supporting member 11 and the supporting member 12 shown in FIG. 3 are joined.
When a current such as an audio signal flows through the meandering coil pattern 23b of the vibration film 23, a magnetic force is generated by electromagnetic induction and electromagnetically coupled to the back side permanent magnet plate 21 and the front side permanent magnet plate 24 to generate audio vibrations in the vibration film 23. To do. When an audio signal that generates vibration with a large amplitude is supplied to the meandering coil pattern of the vibration film, a general polyimide film vibration film has a mutual relationship between a magnetic force and air resistance that tend to generate vibration with a large amplitude. It is deformed by the action and cannot vibrate air.

Since the diaphragm 23a is made of a material harder than a general polyimide film as described above, when an audio signal that causes vibration with a large amplitude is supplied to the meandering coil pattern 23b, the diaphragm 23a described above. An audible sound having a low sound range and a large sound pressure is reproduced without such deformation. Since the diaphragm 23a is supported by the support members 11 and 12 via the damper 25 as shown in FIG. 4, the vibration generated by the current flowing through the meandering coil pattern 23b propagates directly to the support members 11 and 12. do not do. In other words, the diaphragm 23a is configured not to be directly fixed to the support members 11 and 12, so that the vibration of the diaphragm 23a is prevented from being attenuated at the contact portions with the support members 11 and 12.
When a large amplitude vibration is generated in the diaphragm 23a, as shown in FIG. 4, the damper 25 is arranged so that the diaphragm 23a is displaced in its own vibration direction. Deform / stretch to translate. Even when the damper 25 is deformed / expanded, the diaphragm 23a vibrates in accordance with the audio signal flowing through the meandering coil pattern 23b, and generates an audio reproduction sound without the vibration being limited.

  For example, when a plurality of electromagnetic transducers 2 as described above are mounted on the housing 3 of FIG. 1, audio reproduction sound is radiated from each electromagnetic transducer 2 in different directions and operates as a non-directional speaker device. . The front surface of the housing 3 is formed in a folding screen as described above. Since the electromagnetic transducer 2 radiates audio reproduction sound mainly in the vertical direction of the membrane surface of the vibration membrane 23 of the electromagnetic transducer 2, the plurality of electromagnetic transducers 2 are placed on the front surface of the housing 3 as described above. When the plurality of electromagnetic transducers 2 are mounted and arranged in a folding screen, the audio reproduction sound of each electromagnetic transducer 2 is radiated in a plurality of directions, for example, in each direction with an angle α, and around or forward of the housing 3 Produces omnidirectional sound.

As described above, according to the first embodiment, the diaphragm 23a of the diaphragm 23 is made of a material harder than the polyimide film, the damper 25 is provided around the edge of the diaphragm 23a, and the diaphragm 25 is interposed via the damper 25. 23 is supported by the support members 11 and 12, the vibration of the vibration plate 23a is not hindered by the support members 11 and 12, and the vibration plate 23a can be vibrated with a large amplitude, so that bass reproduction is possible. There is an effect that the ability can be improved and the sound pressure level can be improved.
Moreover, since the housing 3 of the speaker device is configured so that a plurality of electromagnetic transducers 2 are mounted in a folding screen, the radiation area of the audio reproduction sound is gained while suppressing the front projection area, and the bass reproduction capability is improved. There is an effect that an improvement in sound pressure level and an omnidirectional sound output can be obtained.

It is explanatory drawing which shows the structure of the speaker apparatus by Embodiment 1 of this invention. 1 is an exploded perspective view showing a configuration of an electromagnetic transducer according to Embodiment 1. FIG. 1 is a cross-sectional view illustrating a configuration of an electromagnetic transducer according to Embodiment 1. FIG. FIG. 6 is an explanatory diagram illustrating an operation of the electromagnetic transducer according to the first embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Speaker apparatus, 2 Electromagnetic transducer, 3 Housing | casing, 10 structure, 11, 12 Support member, 11a. 12a, 21a, 24a Sound radiation hole, 11b, 12b Joint, 21 Back side permanent magnet plate, 22a, 22b Buffer member, 23 Vibration film, 23a Vibration plate, 23b Serpentine coil pattern, 24 Front side permanent magnet plate, 25 Damper .

Claims (4)

A permanent magnet plate having a strip-shaped multipolar magnetization pattern; a vibrating membrane that vibrates by electromagnetic coupling with the permanent magnet plate when a current flows through a serpentine coil pattern formed on the surface; and the permanent magnet plate and the vibrating membrane. In an electromagnetic transducer including a buffer member disposed between and a support member that covers and supports the structure in which the permanent magnet plate, the vibration film, and the buffer member are laminated,
The diaphragm includes a damper that does not transmit vibration of the diaphragm to a support member at an edge portion of the diaphragm on which the meandering coil pattern is formed, and is supported by the support member via the damper. Electromagnetic transducer.   2. The electromagnetic transducer according to claim 1, wherein the vibration film is made of a resin or cone paper which is not easily deformed when a vibration having a larger amplitude than that of the polyimide film is generated on the vibration plate.   A speaker device comprising a plurality of electromagnetic transducers arranged in a folding screen in front of a casing formed in a folding screen.   The speaker device according to claim 3, comprising the electromagnetic transducer according to claim 1.

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