JP2000308193A - Loudspeaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily reproduce high frequency range sounds with respect to a low-price cone-shaped speaker or the like. SOLUTION: The front end part of a voice coil bobbin 112 is bonded to the inner peripheral part of a diaphragm 110, and between a bobbin 112 and a frame 116, a damper 114 is arranged. At the central part of the diaphragm 110, a cap 120 is provided for covering the front end part of the voice coil bobbin 112. The cap 120 has the double structure of an inside cap body 120A and an outside cap body 120B. The inside cap body 120A closes the voice coil bobbin 112 in air-tight state. The outside cap body 120B has an opening part 120C at the central part and the diameter of the opening part 120C is sized more than 3/4 diameter of the outside cap body 120B. By providing such an opening part 120C, the loop-shaped cap body 120B is effectively functioned as a vibrator for reproducing ultrahigh frequency range sounds and ultrahigh frequency range sounds can be easily reproduced in inexpensive configuration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker device capable of reproducing an extremely high frequency band.

[0002]

2. Description of the Related Art FIG. 4 is a cross-sectional view showing a structure of a cone type speaker device using a general dynamic drive system. In this speaker device, an outer peripheral portion of a front end side (upper side in FIG. 4) of a voice coil bobbin 12 is joined to an inner peripheral portion of a truncated cone-shaped diaphragm (cone paper) 10 and a damper The outer periphery of the damper 14 is joined to the inner periphery of the frame 16. The voice coil bobbin 12 has a voice coil 18 mounted on the outer peripheral portion on the rear end side (the lower side in FIG. 4).

A dome-shaped cap 20 is provided at the center of the diaphragm 10 so as to cover the front end of the voice coil bobbin 12.
The center pole portion 22 </ b> C of the yoke 22 is inserted into the rear end of the voice coil bobbin 12. The frame 16 has a truncated conical shape arranged on the outer periphery of the diaphragm 10, and has a flange 16A bent outward at the front end thereof.
Is provided with a gasket 24. An inwardly bent flange portion 16B is formed on the rear end side of the frame 16.

[0004] An arc-shaped edge portion 10 A is formed on the outer peripheral portion of the diaphragm 10 and is joined to the front end of the frame 16. An input terminal 26 is provided on the outer peripheral portion of the frame 16, and a lead wire (kinshi wire) 28 is stretched between the input terminal 26 and the diaphragm 10. A flange 30B on the rear end side of the frame 16 faces the voice coil 18 of the voice coil bobbin 12 and has a plate 30.
Is disposed on the rear end face of the plate 30.
2 are arranged. That is, the gap portion 30A is provided between the plate 30 and the center pole portion 22C of the yoke 22.
Are formed, and the voice coil 18 is arranged. The rear end of the yoke 22 has an outwardly facing flange 22.
A is provided, and the magnet 32 is positioned and mounted by a magnet guide 22B formed on the front surface of the flange portion 22A.

FIG. 5 is a sectional view showing the structure of a cone type speaker device provided with a cancel magnet 36 in the cone type speaker device shown in FIG. In the speaker device shown in FIG. 5, by providing a cancel magnet 36 having a polarity opposite to that of the magnet 32 on the rear surface side of the flange portion 22A of the yoke 22, the resonance sharpness at the lowest resonance frequency of the speaker is reduced in a small device configuration. This makes bass reproduction advantageous.

FIG. 6 is a sectional view showing the structure of a cone type speaker device provided with a shield cover 38 in addition to the cone type speaker device shown in FIG. The shield cover 38 is provided so as to be in close contact with the rear surface of the cancel magnet 36 and to cover the outer periphery of the magnet 32 and the plate 30 from the cancel magnet 36. By providing such a shield cover 38, a magnetic shield effect can be obtained against an external magnetic field, the magnetic flux in the gap of the magnetic circuit is increased, and the resonance sharpness at the lowest resonance frequency of the speaker is slightly reduced. Can be lowered.

FIG. 7 is a sectional view showing a structure in which the cone type speaker device shown in FIG. 6 is provided in a speaker box.
As shown in the figure, the cone type speaker device has a gasket 2
4, and is attached to the front opening 40A of the speaker box 40. The input terminal 26 of the cone type speaker device is connected to an input terminal 44 provided on the back of the speaker box 40 by a lead wire 42. A duct 46 and a duct opening 48 are formed below the speaker box 40.

FIG. 8 is a front view showing the structure of a ribbon-type speaker device using a conventional ribbon-type converter.
FIG. 9 is a sectional view of the ribbon-type speaker device shown in FIG.
This ribbon-type speaker device performs high-band reproduction that is difficult to reproduce with the cone-type speaker device described above, and can reproduce, for example, sound up to 100 KHz with high sound quality. In this ribbon type speaker device, a magnet circuit, a yoke 52, and plates 54, 56 constitute a magnetic circuit, and a ribbon vibration, which serves as a diaphragm and a voice coil, is provided in a gap 58 formed between the end faces of the pair of plates 54, 56. A plate 60 is provided.

The ribbon diaphragm 60 is stretched in the gap 58 with both ends held by holding portions 62 provided on the yoke 50. Both ends of the ribbon diaphragm 60 are connected to secondary transformers 66B of a matching transformer (impedance conversion transformer) 66 via lead wires 64, respectively. Matching transformer 6
A driving current is supplied to the primary-side transformer 66 </ b> A of No. 6, and the matching transformer 66 performs impedance conversion of the driving current and supplies the impedance to the ribbon diaphragm 60. In this loudspeaker device, when the drive current from the matching transformer 66 is supplied to the ribbon diaphragm 60, the drive current drives the ribbon diaphragm 60 according to Fleming's left-hand rule, thereby reproducing the high-temperature region.

[0010]

However, in the above-described ribbon-type speaker device, the gap of the magnetic circuit in which the ribbon diaphragm 60 is disposed is very wide and the length is large, so that the magnetic force is large in the gap. In order to generate the magnet, a magnet having a very large magnetic force is required. Further, in such a ribbon-type speaker device, since the resistance of the voice coil due to the ribbon diaphragm is extremely small, the impedance matching transformer is required as described above, and the cost for this transformer is also high. Therefore, such a ribbon-type speaker device becomes extremely expensive, and it is difficult to use the speaker device for normal use.

SUMMARY OF THE INVENTION An object of the present invention is to provide a speaker device which can easily reproduce high frequencies in various low-cost cone-type speakers.

[0012]

According to the present invention, in order to achieve the above object, a coil bobbin holding a voice coil is joined to an inner peripheral portion of a truncated conical diaphragm, and the coil bobbin is provided at the center of the diaphragm. In a cone type speaker in which a cap for covering a front end is attached and an edge provided on an outer peripheral portion of the diaphragm is joined to a frame to form a vibration system, the cap is concentric with the coil bobbin at a center portion. Wherein the diameter of the opening is 3/4 or more of the diameter of the cap.

[0013] In the speaker device of the present invention, of the cap provided at the front end of the coil bobbin, the central portion that is not required for reproducing the ultra-high frequency band is provided with an opening having a size of at least 3/4 of the diameter of the cap. It was removed by providing. With this shape, the sound radiation area of the cap at the center of the diaphragm can be reduced, and the reverse vibration that cancels the sound pressure in a high frequency range can be reduced. further,
The cap will be lighter. Therefore, the annular cap having an opening in the center effectively functions as a vibrator for reproducing the ultra-high frequency range, and the ultra-high frequency reproduction can be easily performed with an inexpensive configuration. In addition, in order to achieve low-frequency reproduction and sealing of the coil bobbin, the cap has a double structure of an inner cap body and an outer cap body, and the opening is provided in the outer cap body,
The inner cap may have an airtight structure. With such a configuration, it is possible to effectively reproduce the entire band.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a speaker device according to the present invention will be described below. FIG. 1 is a sectional view showing a structural example of a cone type speaker device according to the present invention. This example describes an example of a speaker using a dynamic driving method. In this speaker device, a front end side (upper side in FIG. 1) outer periphery of a voice coil bobbin 112 is joined to an inner periphery of a truncated conical diaphragm (cone paper) 110, and a damper is mounted on a halfway outer periphery of the bobbin 112. The outer periphery of the damper 114 is joined to the inner periphery of the frame 116. The voice coil bobbin 112 has
A voice coil 11 is provided on the outer peripheral portion of the rear end side (the lower side in FIG. 1).
8 is attached.

A dome-shaped cap 120 is provided at the center of the diaphragm 110 so as to cover the front end of the voice coil bobbin 112. The cap 120 has a double structure of an inner cap body 120A and an outer cap body 120B. And the inner cap body 120A is
The voice coil bobbin 112 is formed in a substantially spherical shape.
Is airtightly closed. In addition, the outer cap body 12
0B has an opening 120C concentric with the voice coil bobbin 112 in the center. This opening 12
The diameter of OC is 3/4 or more of the diameter of the outer cap body 120B. For example, when the diameter of the outer cap body 120B is 16.25 mm, the diameter of the opening 120C is 13 mm. Such an opening 1
20C, the outer cap body 120B
Are annularly arranged at regular intervals with respect to the outer peripheral portion of the inner cap body 120A. In this example, each of the cap bodies 120A and 120B is formed of an ultra-light and high-rigidity material, for example, using foamed mica.

In the above-described cap 120, the inner cap body 120A ensures airtightness of the voice coil bobbin 112 and is used for reproduction up to about 40 KHz. In addition, the outer cap body 120B has an opening 120C at the center, so that the sound radiation area at the center of the diaphragm can be reduced, and the reverse vibration that cancels sound pressure at high frequencies is reduced. it can. Further, the weight of the entire cap 120 is reduced. Usually, when formed of an ultralight material, the inner cap body 120A is about 20 mg, but the outer cap body 12A
OB is much lighter. Therefore, the annular cap body 120B having the opening 120C in the center effectively functions as a vibrator for ultrahigh frequency reproduction, and ultrahigh frequency reproduction can be easily performed with an inexpensive configuration.

In the structure of this example, when a normal lightweight rigid material is used, reproduction up to about 700 Hz can be realized very easily. However, reproduction up to 1000 KHz requires a lighter material having higher physical properties, especially It can be easily realized by using a ceramic material. In the high-frequency reproduction, the cap 12 constituting a part of the cone paper is used.
The condition is that the radiation area of the sound at 0 is extremely small. In the configuration of this example, such a condition is realized by providing the opening 120C, and high-frequency reproduction is realized by an inexpensive configuration. It is easily realized. In high-frequency reproduction, even if the cap 120 itself having the above-described structure vibrates in a complicated manner and vibrates sufficiently in the vicinity of the voice coil, the reverse vibration that cancels the sound pressure is reduced, and the cap 120 is easily supersonic. High frequencies can be reproduced.

A center pole portion 122C of the yoke 122 is inserted into the rear end of the voice coil bobbin 112. The frame 116 has a truncated conical shape arranged on the outer periphery of the diaphragm 110, and has a flange 116A bent outward at the front end thereof. A gasket 124 is provided on the flange 116A. ing. An inwardly bent flange portion 116B is formed on the rear end side of the frame 116. An arc-shaped edge portion 110 </ b> A is formed on an outer peripheral portion of the diaphragm 110, and is joined to a front end portion of the frame 116. Frame 11
6, an input terminal 126 is provided on the outer periphery, and a lead wire (kinshi wire) is provided between the input terminal 126 and the diaphragm 110.
128 are passed over.

A plate 130 is arranged on the flange 116B on the rear end side of the frame 116 so as to face the voice coil 118 of the voice coil bobbin 112, and a magnet 132 is arranged on the rear end face of the plate 130. . An outward flange 122A is provided at the rear end of the yoke 122, and a magnet guide 122 formed on the front surface of the flange 122A.
By B, the magnet 132 is positioned and mounted. Further, in the speaker device of this example, the magnet 132
The cancel magnet 136 having the opposite polarity to the yoke 122
By providing the rear side of the flange portion 122A, the resonance sharpness at the lowest resonance frequency of the speaker is reduced in a small device configuration, and bass reproduction is made advantageous.

Further, in the speaker device of this embodiment, a shield cover 138 for covering the magnetic circuit is provided. The shield cover 138 is provided with a cancel magnet 136.
In a state in which the outer periphery of the magnet 132 and the plate 130 is covered by the cancel magnet 136 from the back surface. Such a shield cover 13
By providing 8, a magnetic shielding effect against an external magnetic field can be obtained, the magnetic flux in the gap of the magnetic circuit can be increased, and the resonance sharpness at the lowest resonance frequency of the speaker can be slightly reduced.

FIG. 2 is a sectional view showing a structure in which the speaker device shown in FIG. 1 is provided in a speaker box. As shown, the structure shown in FIG. 7 is common except for the structure of the cap 120 described above. That is, the cone type speaker device of the present example is mounted on the front opening 140A of the speaker box 140 via the gasket 124. The input terminal 126 of the cone type speaker device is connected to an input terminal 144 provided on the back of the speaker box 140 by a lead wire 142. A duct 146 and a duct opening 148 are formed below the speaker box 140.

FIG. 3 is a sectional view showing another example of the structure of the cone type speaker device according to the present invention. In the example shown in FIG. 1 described above, the cap 120 having the double structure is provided, but the cap 150 in this example is a single cap. And also in this cap 150, the coil bobbin 112
Has a concentric opening 150A, and the diameter of the opening 150A is 3/4 of the diameter of the cap 150.
In the present example having the above-described size, high-range reproduction is easily performed by the cap 150 having such an opening 150A. The operation of the cap 150 is the same as the operation of the outer cap body 120B described above. Although a single-layer cap having an opening as in this example is conventionally known, an opening having a size equal to or more than 3/4 of the diameter of the cap 150 as in this example is known. Providing 150A is novel, and can provide a sufficient effect with a simple configuration.

In the above example, the voice coil of the coil bobbin is arranged in the gap of the magnetic circuit.
The dynamic speaker in which the voice coil is vibrated in the gap by supplying the drive signal to the voice coil has been described, but the present invention is not limited to this. For example, by providing a voice coil having both ends short-circuited on a coil bobbin, arranging the voice coil in the gap of the magnetic circuit, and supplying a drive signal to a drive coil arranged near the gap of the magnetic circuit, the voice coil Can be similarly applied to an electromagnetic induction type speaker that vibrates in the gap.

[0024]

As described above, in the speaker device of the present invention, a concentric opening is provided at the center of the cap covering the front end of the coil bobbin with respect to the coil bobbin, and the diameter of this opening is determined by the diameter of the cap. 3/4 of diameter
It was formed in the above size. For this reason, the annular cap having an opening in the center effectively functions as a vibrator for ultrahigh frequency reproduction, and has an effect that ultrahigh frequency reproduction can be easily performed with an inexpensive configuration.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structural example of a cone type speaker device according to the present invention.

FIG. 2 is a cross-sectional view showing a structure in which the speaker device shown in FIG. 1 is provided in a speaker box.

FIG. 3 is a sectional view showing another example of the structure of the cone type speaker device according to the present invention.

FIG. 4 is a cross-sectional view showing a structure of a cone type speaker device using a general dynamic driving method.

5 is a cross-sectional view showing a structure of a cone type speaker device provided with a cancel magnet in the cone type speaker device shown in FIG.

6 is a cross-sectional view showing the structure of a cone-type speaker device provided with a shield cover in addition to the cone-type speaker device shown in FIG.

7 is a cross-sectional view showing a structure in which the cone-type speaker device shown in FIG. 6 is provided in a speaker box.

FIG. 8 is a front view showing the structure of a ribbon-type speaker device using a conventional ribbon-type converter.

9 is a sectional view of the ribbon-type speaker device shown in FIG.

[Explanation of symbols]

110: diaphragm, 112: voice coil bobbin, 1
14 ... Damper, 116 ... Frame, 118 ... Voice coil, 120, 150 ... Cap, 120A ...
Inner cap body, 120B ... Outer cap body, 120
C, 150A ... opening.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D012 BA03 BA06 BA09 BB01 BB03 BB05 BB09 BC05 BD04 CA04 CA08 EA01 FA02 FA08 5D016 AA09 FA02 5D018 AA08 AA10

Claims (6)

[Claims] 1. A coil bobbin holding a voice coil is joined to an inner peripheral portion of a truncated conical diaphragm, and a cap for covering a front end of the coil bobbin is mounted at the center of the diaphragm, and an outer periphery of the diaphragm is provided. In a cone type speaker in which an edge part provided in a part is joined to a frame to form a vibration system, the cap has a concentric opening with respect to the coil bobbin in a center part, and the diameter of the opening part is A speaker device having a size that is at least 3/4 of the diameter of the cap. 2. The speaker device according to claim 1, wherein the cap has a double structure of an inner cap body and an outer cap body, and the opening is provided in the outer cap body. 3. The inner cap body is formed in a substantially spherical shape to close a front end of the coil bobbin, and the outer cap body is disposed apart from an outer peripheral surface of the inner cap body. The speaker device according to claim 2. 4. A dynamic speaker in which a voice coil of the coil bobbin is arranged in a gap of a magnetic circuit and a driving signal is supplied to the voice coil to vibrate the voice coil in the gap. The speaker device according to claim 1, wherein 5. The voice coil of the coil bobbin is a coil having both ends short-circuited. The voice coil is disposed in a gap of the magnetic circuit, and a driving signal is supplied to a driving coil disposed near the gap of the magnetic circuit. The speaker device according to claim 1, wherein the speaker device is an electromagnetic induction type speaker that vibrates the voice coil in a gap portion. 6. The speaker device according to claim 1, wherein the cap is formed of an ultra-light and highly rigid material.