JP2007318345A - Speaker system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reproduce a sound of high sound quality by improving an available opening angle range of a subcone and reducing disturbance to radiation of a sound wave from a main diaphragm even when a speaker system is made more compact, thinner, and more lightweight than conventional one and provided with the subcone. <P>SOLUTION: The speaker system 100 is provided with a diaphragm (first diaphragm) 8, and the subcone (second diaphragm) 110. The diaphragm 8 has an inner peripheral edge 8a coupled to a voice coil bobbin 6 and an outer peripheral edge 8b coupled to a frame 5 through an edge 9, and a peak part 8c is formed between the inner peripheral edge 8a and outer peripheral edge 8b, which are disposed on a sound radiation side as compared with the peak part 8c. The subcone 110 has an inner peripheral edge coupled to the voice coil bobbin 6, and is disposed on the sound radiation side of the diaphragm and in a cone shape which is opened to the sound radiation side. Even when the subcone is provided, therefore, the availability of the opening angle of the subcone is improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a speaker device.

  A speaker device equipped in an audio device such as an audio system is a so-called electric-acoustic converter that converts an audio signal (electric energy) from an amplifier into sound (acoustic energy). Loudspeaker devices can be roughly divided into electrodynamic, electrostatic, piezoelectric, discharge, electromagnetic, etc., but at present, electrodynamic types that have conditions such as reproduction frequency band and conversion efficiency. (Dynamic type) dominates.

  As an example of a conventional electrodynamic speaker device, a so-called cone speaker is known. The speaker device is used as a part of an audio system, for example, and mounted and installed in a narrow space in a door of an automobile, a case of a flat-type electronic display device, or a case having various other forms. There are many. In that case, the speaker device needs to be formed as thin as possible so that the speaker device can be easily mounted in a housing of a limited size. However, it is difficult to reduce the thickness of the cone type speaker.

  For example, in the speaker device disclosed in Patent Document 1, a speaker device including a diaphragm having a top portion between an inner peripheral edge and an outer peripheral edge is disclosed. That is, in this speaker device, since the diaphragm has a cross-sectional shape that is folded back at the top, the speaker device can be made thinner than a speaker device that includes a general cone-shaped diaphragm.

  In the speaker device disclosed in Patent Document 2, as shown in FIG. 1A, the inner peripheral edge of the diaphragm 8J is connected to the voice coil bobbin 6J around which the voice coil 7J is wound. A continuous portion (top portion 8c) is formed between the inner periphery and the outer periphery. The diaphragm 8J includes an inner diaphragm portion 81J whose opening diameter increases as the distance from the inner peripheral edge increases, and an outer diaphragm portion 82J continuous to the outer periphery of the inner diaphragm portion 81J via a continuous portion (top portion 8c). In addition, the speaker device includes a sub cone 110J and a center cap portion 11J that open from the connecting portion between the voice coil bobbin 6J and the diaphragm 8J toward the acoustic radiation side and whose opening diameter is smaller than that of the inner diaphragm portion 82J.

Japanese Patent No. 3634855 JP-A-8-205283

  However, in the speaker device described in Patent Document 2 described above, for example, as shown in FIG. 1B, the sub cone 110J opens in the same direction as the inner diaphragm portion 81J of the diaphragm 8J. There is a problem that the angle between 110J and the inner diaphragm 81J is limited.

  Further, as shown in FIG. 1C, the inner diaphragm portion 81J and the sub cone 110J are disposed close to each other, and the sub cone 110J has an adverse effect on the sound wave emission from the inner diaphragm portion 81J. is there.

  By the way, further downsizing and thinning of the speaker device are desired by downsizing and space-saving of the housing to which the speaker device is mounted. Since the ring magnet and ring plate of the outer magnet type magnetic circuit are formed on the outer side in the radial direction of the voice coil because it is driven by the magnetic circuit, the speaker device can be reduced in size and thickness. It was difficult.

  Also, the ring magnet of the outer magnet type magnetic circuit is relatively heavy. Further, if the ring-shaped magnet is simply reduced in size, the magnetic flux density between the magnetic gaps is reduced, the driving force of the diaphragm is lowered, and the sound quality of the reproduced sound may be lowered.

  This invention makes it an example of a subject to cope with such a problem. That is, the speaker device can be made smaller, thinner, lighter, the degree of freedom of the opening angle of the sub cone can be improved even when the sub cone is provided, and the sound wave from the main diaphragm can be improved. It is an object of the present invention to reduce the obstruction of radiation and to reproduce sound with high sound quality.

  In order to achieve such an object, the present invention comprises at least the configurations according to the following independent claims.

  In the speaker device according to the first aspect, the inner peripheral edge is connected to the voice coil bobbin, the outer peripheral edge is connected to the frame via the edge, and a top portion is formed between the inner peripheral edge and the outer peripheral edge. The inner peripheral edge and the outer peripheral edge are connected to the voice diaphragm bobbin with a first diaphragm formed in a shape positioned on the acoustic radiation side as compared to the top, and the acoustic of the first diaphragm It has a cone-shaped 2nd diaphragm opened to the said acoustic radiation side while being located in the radiation | emission side, It is characterized by the above-mentioned.

  In a speaker device according to an embodiment of the present invention, an inner peripheral edge is connected to a voice coil bobbin, an outer peripheral edge is connected to a frame via an edge, and a top is formed between the inner peripheral edge and the outer peripheral edge. And the outer periphery of the first diaphragm formed in a shape positioned on the acoustic radiation side relative to the top, and the inner periphery of the voice coil bobbin is connected to the first diaphragm and positioned on the acoustic radiation side of the first diaphragm. And a cone-shaped second diaphragm opened to the acoustic radiation side.

  In the speaker device having the above configuration, the inner peripheral edge of the second diaphragm is connected to the voice coil bobbin, and is located on the acoustic radiation side of the first diaphragm, and is formed in a cone shape opened to the acoustic radiation side. The speaker device can be made smaller than before. Further, even when the second diaphragm (subcone) is provided, the degree of freedom of the opening angle of the subcone is improved as compared with the conventional general diaphragm. Since the second diaphragm opens in the opposite direction with respect to the diaphragm on the inner side than the top of the first diaphragm, it is possible to reduce the blockage of the sound wave from the first diaphragm.

  Hereinafter, a speaker device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 2 is a diagram for explaining a speaker device 100 according to an embodiment of the present invention. Specifically, FIG. 2 is a front view of the speaker device 100 as viewed from the front side (acoustic radiation side). FIG. 3 is a cross-sectional view taken along the line AA of the speaker device 100 shown in FIG.

  The speaker device 100 includes an inner magnet type magnetic circuit 4 including a yoke 1, a plate 2, and a magnet 3, a frame (speaker frame) 5, a voice coil 7 wound around a voice coil bobbin 6, and a diaphragm 8. And an edge 9, a damper 10, a center cap portion 11, a lead wire 12, and a sub cone 110.

  The inner magnet type magnetic circuit 4 corresponds to an embodiment of the inner magnet type magnetic circuit according to the present invention. The diaphragm 8 corresponds to an embodiment of the first diaphragm according to the present invention. The frame 5 corresponds to an embodiment of the frame according to the present invention. The sub cone 110 corresponds to an embodiment of the second diaphragm according to the present invention.

  The magnetic circuit 4 according to this embodiment includes a yoke 1, two magnets 3 (31), a magnet 3 (32), two plates 2 (21), and a plate 2 (22). The plate 2 (21) is also called a center plate.

  The yoke 1 is joined to the bottom surface of the magnet 3 (31), and radially extends radially outward from the bottom portion 1a and bends toward the acoustic radiation direction (front). 2 (21) and a side portion 1b having a shape extending to the side. Further, the bottom 1a and the side 1b of the yoke 1 are integrally formed. In the yoke 1 according to the present embodiment, an inclined surface portion 1d is formed at an outer peripheral side corner portion of the end portion on the acoustic radiation side of the side portion 1b. A hole 1 h is formed in the center of the yoke 1. As a material for forming the yoke 1, for example, an inorganic material, a metal, a magnetic material such as iron, or the like can be employed.

  As shown in FIG. 3, the magnetic circuit 4 includes a plate 2 (21) disposed between the magnet 3 (31) and the magnet 3 (32), and the plate 2 (22) on the magnet 3 (32). Is arranged. The magnet 3 (31) and the magnet 3 (32) are arranged so that the same poles face each other, and the magnetic circuit 4 having such a configuration is referred to as a so-called repulsive magnetic circuit. By adopting a repulsive magnetic circuit, it is possible to obtain effects such as a relatively high magnetic flux density at the magnetic gap 4g and high sensitivity.

  As the material for forming the magnets 3 (31) and 3 (32), for example, permanent magnets such as neodymium-based, samarium-cobalt-based, alnico-based, and ferrite-based magnets can be employed. As a material for forming the plates 2 (21) and 2 (22), for example, a metal such as iron or a magnetic material can be employed.

  In the magnetic circuit 4 according to the present embodiment, the yoke 1, the magnet 3 (31), the plate 2 (21), the magnet 3 (32), and the plate 2 (22) are formed concentrically with respect to the central axis o. Specifically, they are arranged close to each other on the same axis and overlapping along the direction of the central axis o.

  Moreover, the magnet 3 (31), the plate 2 (21), the magnet 3 (32), and the plate 2 (22) may be formed in a ring shape. The magnets 3 (31) and 3 (32) having this configuration are magnetized so that the same poles face each other along the thickness direction (vibration direction), and the inner and outer surfaces of the magnets 3 (31) and 3 (32) A radial magnetic circuit provided with a so-called radial ring magnet in which a magnetic gap is formed and the magnetic flux flows in the same direction as the magnetic flux flowing in the magnetic circuit 4 may be adopted as the magnetic circuit 4. By adopting a radial type magnetic circuit as the magnetic circuit 4, effects such as improvement in magnetic efficiency, reduction in thickness, and reduction in size can be obtained.

  Further, in the magnetic circuit 4 according to the present embodiment, the magnet 3 (31) is surrounded by the yoke 1 such as iron, so that magnetic leakage can be reduced.

  Further, as shown in FIG. 3, the magnetic circuit 4 has a magnetic gap 4g for driving the voice coil 7, and magnetic fluxes from the magnets 3 (31) and 3 (32) are concentrated in the magnetic gap 4g. Yes. Specifically, the magnetic gap 4g is formed between the inner surface of the side portion 1b of the yoke 1 and the outer surface of the plate 2 (21), and is formed with a substantially uniform gap over the entire circumference. ing.

  As described above, the magnetic circuit 4 according to the present embodiment employs a so-called repulsive magnetic circuit including two magnets 3 (31) and 3 (32) arranged so that the same poles face each other. It is not limited. For example, the speaker device 100 may include a magnetic circuit 4a having a configuration in which the magnet 3 (31) is disposed on the pole portion 1a of the yoke 1 and the plate 2 (21) is disposed on the magnet 3 (31). . Since the speaker device having this configuration includes the magnetic circuit 4a including the yoke 1, the plate 2 (21), and the magnet 3 (31), the speaker device can be made thinner and more compact. There are effects such as.

  As shown in FIGS. 2 and 3, in the frame 5, the magnetic circuit 4 is disposed at the center of the back flat part (bottom part) 51, and the opening 5 a is formed at the center of the back flat part 51. Further, the frame 5 has a cone-shaped portion 52 that is bent from the outer peripheral edge of the back flat portion 51 toward the acoustic radiation side. A flat part 53 to which the outer peripheral edge 10a of the damper 10 is fixed is formed at the middle stage of the cone-shaped part 52 of the frame 5, and the outer peripheral edge 9a of the edge 9 is directly or near the upper front side of the cone-shaped part 52. A flat portion 54 that is fixed via the joining member 90 is formed, and a flange 55 is formed on the outer peripheral portion of the frame 5. The cone-shaped portion 52 has one or a plurality of window portions 52 a and arm portions 52 b formed between the flat portion 53 and the flat portion 54.

  In the frame 5 according to the present embodiment, the back flat portion 51, the cone-shaped portion 52, the flat portion 53, the flat portion 54, and the flange 55 are integrally formed.

  The voice coil 7 is formed, for example, by winding an electric wire around a cylindrical voice coil bobbin 6, and is fixed to the voice coil bobbin 6 so that at least a part of the voice coil 7 can freely vibrate within the magnetic gap 4 g of the magnetic circuit 4. Be placed.

  The center cap portion 11 is formed to have an outer diameter substantially equal to the inner diameter of the voice coil bobbin 6, for example, and is connected to the voice coil bobbin 6 by being fixed to the voice coil bobbin 6 with an adhesive or the like. That is, the center cap portion 11 is formed so as to cover the sound emitting side end portion of the voice coil bobbin 6. The center cap part 11 according to the present embodiment is formed in a convex shape toward the acoustic radiation side. The center cap portion 11 may be formed in a concave shape to reduce the thickness of the speaker device, and is not particularly limited.

  The sub cone 110 has an inner peripheral edge connected to the voice coil bobbin 6 and is formed in a cone shape which is located on the acoustic radiation side of the diaphragm 8 and opened to the acoustic radiation side. Since the vicinity of the inner peripheral portion of the diaphragm 8 is opened on the side opposite to the acoustic radiation direction, the opening angle (half apex angle) of the sub cone 110 can be set relatively freely.

  For example, the opening angle (half apex angle) of the sub-cone 110 is defined according to the frequency band that reinforces the frequency characteristics of the sound wave emitted by the diaphragm 8. By providing the sub cone 110 having the above configuration, sound waves having a desired frequency characteristic are radiated from the diaphragm 8 and the sub cone 110. Since the sub cone 110 according to the present embodiment has a smaller outer diameter than the diaphragm 8, the high frequency characteristics of the sound pressure can be improved.

  Further, for example, the opening angle (half apex angle) of the sub cone 110 is defined according to the directivity of the sound wave emitted from the sub cone 110. By providing the sub cone 110 having the above-described configuration, it is possible to emit a sound wave having strong directivity from the sub cone 110 in a desired direction.

  Further, by forming the outer diameter of the sub cone 110 on the inner side of the top portion 8c of the diaphragm 8, the degree of covering the diaphragm 8 can be reduced as compared with the conventional case, and the reproduction frequency band can be widened.

  In the present embodiment, the center cap portion 11 and the sub cone 110 are integrally formed.

  As a material for forming the diaphragm 8, for example, various materials such as a polymer such as resin, paper, and metal can be employed. The diaphragm 8 has a ring-shaped acoustic radiation surface extending from the inner peripheral edge 8 a to the outer peripheral edge 8 b, and the inner peripheral edge 8 a is formed with a central hole for connecting the voice coil bobbin 6. The voice coil bobbin 6 is fitted into the central hole of the diaphragm 8 and fixed by an adhesive or the like, whereby the inner peripheral edge 8 a of the diaphragm 8 is connected to the vicinity of the sound radiation side end of the voice coil bobbin 6. An outer peripheral edge 8 b of the diaphragm 8 is attached to the frame 5 through an edge 9.

  The edge 9 is formed in a ring shape, for example. As the edge 9, for example, various edges such as a roll edge, a V-shaped edge, a corrugation edge, and a flat edge can be employed. A roll edge is employed as the edge 9 according to the present embodiment. The edge 9 has appropriate compliance and rigidity, and the inner peripheral edge 9b of the edge 9 is connected to the diaphragm 8 by being fixed to the outer peripheral edge 8b of the diaphragm 8 with an adhesive or the like. Further, as described above, the outer peripheral edge 9 a of the edge 9 is connected to the frame 5 by being fixed to the flat portion 54 of the frame 5 directly or via the joining member 90. As described above, the outer peripheral edge 8 b of the diaphragm 8 is connected to the frame 5 through the edge 9. Therefore, the edge 9 elastically supports the outer peripheral edge of the diaphragm 8.

  As shown in FIGS. 2 and 3, the diaphragm 8 has a top 8c formed between the inner peripheral edge 8a and the outer peripheral edge 8b, and the inner peripheral edge 8a and the outer peripheral edge 8b are compared to the top part 8c. And formed in a shape located on the acoustic radiation side. The top 8c of the diaphragm 8 is fixed to the inner peripheral edge 10b of the damper 10 with an adhesive or the like.

  The damper 10 is formed, for example, by impregnating a resin into a cloth and thermoforming it. As the damper 10, for example, a damper having various shapes such as a circular damper having a concentric corrugation can be adopted. The damper 10 has appropriate compliance and rigidity, and an outer peripheral edge 10 a of the damper 10 is connected to the frame 5. The top 8c of the diaphragm 8 is supported by the inner peripheral edge 10b. Further, as shown in FIG. 3, the inner peripheral edge 10 b of the damper 10 according to the present embodiment is bent toward the acoustic radiation side and is formed in a shape bent along the inclined surface of the diaphragm 8, such as an adhesive. Therefore, the inner peripheral edge 10b of the damper 10 and the top 8c of the diaphragm 8 are securely fixed.

  In the speaker device 100, as shown in FIGS. 2 and 3, the damper 10, the flat portion 53 of the frame 5, the voice coil 7, the plate 2 (21), and the top portion 8c of the diaphragm 8 are substantially in the same plane. It is formed as follows.

  In the speaker device 100 configured as described above, since the top 8c of the diaphragm 8 is set to be the height of the damper 10, the variation in the height of the top 8c of the diaphragm 8 can be reduced, and high quality sound can be obtained. Can be played. Further, since the top 8c of the diaphragm 8 is set to be the height of the damper 10, the assembly workability is improved.

  The damper 10 configured as described above elastically supports each of the diaphragm 8, the center cap portion 11, the voice coil bobbin 6, and the voice coil 7 together with the edge 9 at a predetermined position of the speaker when the speaker is not driven, and within the magnetic gap 4g. The voice coil 7 and the voice coil bobbin 6 that are arranged on the side of the yoke 1 are elastically held at a position where they are not brought into contact with a portion constituting the magnetic circuit 4 such as the side portion 1 b of the yoke 1.

  The damper 10 has a function of elastically supporting the center cap portion 11, the diaphragm 8, the voice coil bobbin 6, and the voice coil 7 along the vibration direction (center axis (o) direction) in driving the speaker.

  Further, as described above, the yoke 1 is formed with the inclined surface portion 1d at the outer peripheral side corner portion of the end portion on the acoustic radiation side of the side portion 1b. Even if it vibrates along the direction o), the diaphragm 8 can be prevented from coming into contact with the yoke 1.

  Further, both ends of the voice coil 7 are drawn out along the voice coil bobbin 6 and the diaphragm 8, respectively. For example, as shown in FIG. Connected to.

  The lead wire 12 is, for example, a tinker wire that is strong against bending and formed by combining a plurality of thin electric wires, and is connected to an input terminal portion 14 fixed to the frame 5 through a hole 13 formed in the diaphragm 8. .

  In the speaker device 100 configured as described above, when an audio signal is input to the input terminal unit 14, a current corresponding to the audio signal is supplied to the voice coil bobbin 6 via the lead wire 12. As a result, the voice coil bobbin 6 in the magnetic gap 4g is electromagnetically driven, and the center cap portion 11 and the diaphragm 8 connected to the voice coil bobbin 6 are driven along the piston vibration direction while being supported by the edge 9 and the damper 10. Thus, acoustic energy corresponding to the audio signal is acoustically radiated from the diaphragm 8.

  4A to 4C are diagrams for explaining the diaphragm of the speaker device 100 shown in FIG. Specifically, FIG. 4A is a cross-sectional view illustrating a specific example of the cross-sectional shape of the diaphragm of the speaker device 100. FIG. 4B is a cross-sectional view for explaining another specific example of the cross-sectional shape of the diaphragm of the speaker device 100. FIG. 4C is a diagram for explaining in detail the cross-sectional shape of the diaphragm shown in FIG.

  In the present embodiment, the diaphragm 8 has the following structure in order to suppress the overall height of the speaker device 100, suppress the divided vibration of the diaphragm 8 in the driving state, and improve the sound pressure frequency characteristics in the high frequency range.

  Specifically, as shown in FIGS. 2, 3, 4 (A) to 4 (C), the diaphragm 8 is formed with a folded portion between the inner peripheral edge 8 a and the outer peripheral edge 8 b, The folded portion forms the top 8c.

  The top portion 8c is a tip portion of the folded portion of the diaphragm 8, and is formed by being folded at an acute angle so that the inner peripheral edge 8a and the outer peripheral edge 8b are located on the acoustic radiation side as compared with the top portion 8c.

  For example, as shown in FIGS. 4A to 4C, the diaphragm 8 includes an inner diaphragm 81 formed on the inner peripheral edge 8 a side from the top 8 c of the diaphragm 8, and the top of the diaphragm 8. The outer diaphragm 82 is formed on the outer peripheral edge 8b side from 8c. The inner diaphragm portion 81 and the outer diaphragm portion 82 are integrally formed.

  Specifically, as shown in FIG. 4A, the diaphragm 8 has a cross-sectional shape of the inner diaphragm 81 formed on the inner peripheral edge 8a side from the top 8c of the diaphragm 8 so that it protrudes toward the acoustic radiation side. The cross-sectional shape of the outer diaphragm portion 82 formed on the outer peripheral edge 8b side from the top portion 8c of the diaphragm 8 is formed in a convex shape on the acoustic radiation side.

  As shown in FIG. 4B, in the diaphragm 8, the cross-sectional shape of the inner diaphragm 81 is formed in a convex shape on the acoustic radiation side, and the cross-sectional shape of the outer diaphragm 82a is substantially linear. It may be formed.

  4C, the diameter φa of the top 8c of the diaphragm 8 is smaller than the diameter φb of the outer peripheral edge 8b of the diaphragm 8. The diameter φa of the top 8c is larger than the diameter φc of the voice coil bobbin 6.

  Further, as shown in FIG. 4C, the diaphragm 8 according to the present embodiment has a length r81 along the radial direction from the inner peripheral edge 8a to the top part 8c, and extends from the top part 8c to the outer peripheral edge 8b in the radial direction. Preferably, it is formed to be shorter than the length r82.

  Further, in the diaphragm 8 according to the present embodiment, as shown in FIG. 4C, the diameter φb of the outer peripheral edge 8b of the diaphragm 8 is not more than four times the height d8 of the outer peripheral edge 8b of the diaphragm 8. Preferably there is. The height d8 of the outer peripheral edge 8b of the diaphragm 8 is a distance along the acoustic radiation direction from the top 8c of the diaphragm 8 to the outer peripheral edge 8b of the diaphragm 8.

  In the speaker device 100 having the above-described configuration, the vibration surface extending from the inner peripheral edge 8a to the outer peripheral edge 8b is formed by being folded back at the top 8c, so that the height from the top 8c to the inner peripheral edge 8a or the outer peripheral edge 8b is the vibration. This is the total height of the plate 8. Therefore, the overall height of the diaphragm 8 can be made lower than that of a conventional cone-shaped diaphragm having the same aperture (outer diameter of the diaphragm) and voice coil diameter (inner peripheral edge 8a of the diaphragm 8).

  Further, in the diaphragm 8 according to the present embodiment, the diameter φa of the top 8c of the diaphragm 8 is optimized with respect to the diameter φb of the outer peripheral edge 8b of the diaphragm 8, and the inner diaphragm 81 is formed in a convex shape. And the cross-sectional shape of the outer diaphragm 82 is formed in a convex or substantially linear shape, the diameter φb and the height d8 of the outer peripheral edge 8b of the diaphragm 8 are optimized, etc. Characteristics can be improved.

  Even if the diaphragm 8 is formed by any one of the above conditions or a combination of the two conditions and a combination of the three conditions, an effect of improving the high frequency reproduction frequency characteristic can be obtained.

  That is, the speaker device 100 according to the present embodiment can obtain effects such as making the speaker device smaller, thinner, and lighter than the conventional one, and can reproduce sound with high sound quality.

  Next, in order to confirm the performance of the magnetic circuit 4 of the speaker device 100 according to an embodiment of the present invention, the inventor of the present application performed a simulation of the magnetic flux density distribution of the magnetic circuit 4 using a computer.

  FIG. 5A and FIG. 5B are diagrams for explaining the simulation result of the magnetic flux density of the magnetic circuit. Specifically, FIG. 5A is a diagram showing a magnetic flux distribution of a magnetic circuit in which an inclined surface portion is not formed at the yoke end. FIG. 5B is a diagram showing a magnetic flux distribution of a magnetic circuit in which an inclined surface portion is formed at the end of the yoke. FIG. 6 is a diagram for explaining the magnitude of the magnetic flux density in the magnetic gap 4g of the magnetic circuit 4 shown in FIGS. 5 (A) and 5 (B). The vertical axis shows the magnitude of magnetic flux density (T: Tesla), and the horizontal axis shows the position (mm) along the vibration direction in the magnetic gap. In FIG. 6, the magnitude of the magnetic flux density of the magnetic circuit 4 having the structure shown in FIG. 5A is indicated by a dotted line, and the magnitude of the magnetic flux density of the magnetic circuit 4 having the structure shown in FIG. Is shown. In FIG. 6, the vicinity of the boundary between the center plate 2 and the magnet 3 (31) corresponds to 0 mm, the vicinity of the center of the center plate 2 corresponds to 2 mm, and the vicinity of the boundary between the center plate 2 and the magnet 3 (32) corresponds to 4 mm. .

  As shown in FIG. 5A, it can be confirmed that the magnetic flux is concentrated near the end of the plate 2 (21) sandwiched between the magnet 3 (31) and the magnet 3 (32). Moreover, it can be confirmed that the side portion 1b of the yoke 1 prevents magnetic flux leakage. Since the repulsive magnetic circuit is employed in this way, the magnetic flux density of the magnetic gap 4g can be made relatively high.

  Further, as shown in FIG. 5B, in the magnetic circuit 4 in which the inclined surface portion 1d is formed at the end of the side portion 1b of the yoke 1, the inclined surface portion 1d is compared with the magnetic circuit shown in FIG. It can be confirmed that the flow of magnetic flux in the vicinity is improved. It was also confirmed that the magnetic flux was flowing without closing near the end of the magnet 3 (31).

  Further, as shown in FIG. 6, the magnetic circuit 4 has a maximum magnetic flux density (about 1.04 T) near the center portion (around 2 mm) of the center plate 2 (21), and ± 1 mm from the vicinity of the center portion. In the vicinity, it was confirmed that the magnitude of the magnetic flux density was substantially uniform. Further, as shown by the dotted line, the inclined surface portion 1d is formed at the end portion of the side portion 1b of the yoke 1, as shown by the solid line, as compared with the case where the inclined surface portion 1d is not formed at the end portion of the side portion 1b of the yoke 1. In this case, it was confirmed that the magnitude of the magnetic flux density was increased.

  As described above, by forming the inclined surface portion 1d at the end portion of the side portion 1b of the yoke 1 as the magnetic circuit 4, the magnitude of the magnetic flux density of the magnetic gap 4g of the magnetic circuit 4 can be further increased. .

  Further, as described above, the inclined surface portion 1d is formed on the outer peripheral side corner portion of the end portion on the acoustic radiation side of the side portion 1b of the yoke 1, so that the diaphragm 8 is vibrated in the vibration direction (center axis (o)) when the speaker is driven. The vibration plate 8 can be prevented from coming into contact with the yoke 1 even when it vibrates along the direction.

  Next, in order to confirm the performance of the sub cone 110 of the speaker device 100 according to the embodiment of the present invention, the inventor of the present application performed a simulation on the sound pressure frequency characteristics of the speaker device 100.

  FIG. 7 shows a simulation result of the sound pressure frequency characteristics of the speaker device 100 according to the present invention including the diaphragm 8, the center cap portion 11, and the sub cone 110, and the sound pressure of the speaker device including the diaphragm 8 and the center cap portion 11. It is a figure which shows the simulation result of a frequency characteristic. In FIG. 7, the solid line indicates the simulation result of the sound pressure frequency characteristic of the speaker device 100 including the sub cone 110, and the broken line indicates the simulation result of the sound pressure frequency characteristic of the speaker device not including the sub cone 110.

  As shown in FIG. 7, the sound pressure level is about 81 dB at a frequency of 100 Hz and has a substantially flat characteristic from 100 Hz to 1 kHz. The sound pressure level rises from around 1 kHz to 5 kHz, and from 5 kHz to 15 kHz. Peak dip occurs. At this time, as shown by a dotted line, when the sub cone 110 is not provided, the high frequency limit frequency is reached in the vicinity of 20 kHz. Further, when the sub cone 110 is provided as shown by the solid line, a level peak of about 84 dB can be detected in the vicinity of about 18 kHz.

  That is, by providing the sub cone 110, the high frequency characteristics can be improved as shown in FIG. Further, by providing the sub cone 110 as shown in FIG. 7, the high frequency limit frequency can be widened.

  As described above, in the speaker device 100 according to the present invention, the inner peripheral edge 8a is connected to the voice coil bobbin 6, the outer peripheral edge 8b is connected to the frame 5 via the edge 9, and the inner peripheral edge 8a and the outer peripheral edge 8b are connected. A vibration plate (first vibration plate) 8 is formed between the voice coil bobbin 6 and the inner peripheral edge 8a and the outer peripheral edge 8b. Since the inner peripheral edge is connected and the cone-shaped sub-cone (second diaphragm) 110 located on the acoustic radiation side of the diaphragm 8 and opened on the acoustic radiation side is provided, the sub-cone is provided. In addition, the degree of freedom of the opening angle of the sub cone can be improved.

  Further, since the sub cone 110 having the above-described configuration is provided, it is possible to reduce the sound wave emission from the diaphragm 8 and to widen the reproduction band, and to reproduce the sound with high sound quality.

  In addition, since the sub cone 110 having the above-described configuration is provided, the high-frequency reproduction limit frequency can be expanded as compared with the conventional case.

  Further, in the speaker device 100 according to the present invention, the inner peripheral edge 8a is connected to the voice coil bobbin 6, the outer peripheral edge 8b is connected to the frame 5 through the edge 9, and the apex 8c is formed between the inner peripheral edge 8a and the outer peripheral edge 8b. And the voice coil bobbin 6 connected to the inner peripheral edge 8a of the diaphragm 8 and the inner peripheral edge 8a and the outer peripheral edge 8b formed on the acoustic radiation side of the top 8c. Since the internal magnetic type magnetic circuit 4 that drives the arranged voice coil 7 is included, for example, the speaker device 100 according to the present invention has the magnet 3 formed at the center thereof compared to the external magnetic type magnetic circuit. The speaker device can be made smaller, thinner, and lighter than before.

  Further, since the magnetic efficiency is improved by adopting the repulsive magnetic circuit, it is possible to reproduce sound with high sound quality.

  Further, the inner magnet type magnetic circuit 4 is radially formed from the magnet 3 (31), the plate 2 (21) disposed on the magnet 3 (31), and the bottom 1a joined to the bottom surface of the magnet 3 (31). And the yoke 1 having a shape that extends radially outward and bends in the direction of acoustic radiation and extends to the side of the plate 2 (21), so that the magnet 3 (31) is a yoke 1 made of iron or the like. Since the structure is surrounded by the frame 5, magnetic leakage can be prevented.

  Further, the thickness of the yoke 1 and the frame 5 for preventing magnetic leakage can be reduced. That is, the weight can be reduced.

  Further, the damper 10 has the outer peripheral edge 10a of the damper 10 coupled to the frame 5 and supports the top 8c of the diaphragm 8 by the inner peripheral edge 10b of the damper. Therefore, the damper 10 can freely vibrate the top 8c of the diaphragm 8. Can be supported. In addition, since the top 8c of the diaphragm 8 is set to be the height of the damper 10, variations in the height of the top 8c of the diaphragm 8 can be reduced, and sound can be reproduced with high quality. . Further, since the top 8c of the diaphragm 8 is set to be the height of the damper 10, the assembly workability is improved.

  Further, since a repulsive magnetic circuit is employed as the inner magnet type magnetic circuit 4, even when the speaker device 100 is reduced in size and thickness, the magnetic flux density of the magnetic gap 4g can be improved. It is possible to improve the power and to reproduce the sound with high quality.

  Further, the yoke 1 disposed around the inner magnet type magnetic circuit 4 has the inclined surface portion 1d formed at the outer peripheral side corner portion of the end portion on the acoustic emission side of the side portion 1b of the yoke 1, and therefore the magnetic gap 4g. The magnetic flux density can be improved, and the driving force for the diaphragm 8 can be improved.

  Further, as described above, the speaker device 100 includes the inner magnet type magnetic circuit 4 including the magnet 3, the plate 2, and the yoke 1, and the voice coil 7 includes the outer surface of the plate 2 (21) and the yoke 1. The voice coil 7, the plate 2 (21), the top 8 c of the diaphragm 8, and the damper 10 are substantially flush with the magnetic gap 4 g between the inner surfaces of the two. Since the sound emitting side end of the side portion 1b of the yoke 1 is positioned on the sound radiation side from the top portion 8c of the diaphragm 8, and the inclined portion 1d is provided at the end of the yoke 1, the speaker device 100 can be reduced in size and thickness.

  The present invention is not limited to the embodiment described above. You may combine embodiment and the specific example which were mentioned above.

  In the embodiment described above, a repulsive magnetic circuit is employed as the magnetic circuit 4, but the present invention is not limited to this form. For example, the magnet 3 (32) and the plate 2 (22) may be omitted. By adopting the magnetic circuit having this configuration, the speaker device can be made thinner and smaller.

  In the above-described embodiment, the center cap portion 11 is formed in a convex shape on the acoustic radiation side, but is not limited to this form. For example, as shown in FIG. 8, the center cap portion 11b may be formed in a concave shape on the acoustic radiation side.

(A)-(C) are the figures for demonstrating the conventional speaker apparatus. It is a figure for demonstrating the speaker apparatus 100 which concerns on one Embodiment of this invention, and is the front view seen from the front side (acoustic radiation side) of the speaker apparatus. It is sectional drawing along the AA line of the speaker apparatus 100 shown in FIG. (A)-(C) are the figures for demonstrating the diaphragm of the speaker apparatus 100 shown in FIG. (A) is sectional drawing explaining one specific example of the cross-sectional shape of the diaphragm of the speaker apparatus 100, (B) is sectional drawing for demonstrating the other specific example of the cross-sectional shape of the diaphragm of the speaker apparatus 100. (C) is a figure for demonstrating in detail the cross-sectional shape of the diaphragm shown to (A). (A), (B) is a figure for demonstrating the simulation result of the magnetic flux density of a magnetic circuit. It is a figure for demonstrating distribution of the magnetic flux density in the magnetic gap 4g of the magnetic circuit 4 shown to FIG. 5 (A) and FIG. 5 (B). It is a figure which shows the sound pressure frequency characteristic of the speaker apparatus 100 which concerns on this invention provided with the diaphragm 8, the center cap part 11, and the sub cone 110, and the sound pressure frequency characteristic of the speaker apparatus provided with the diaphragm 8 and the center cap part 11. FIG. It is sectional drawing for demonstrating the speaker apparatus 100a which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Yoke 1a Bottom 1b Side 2 Plate 3 Magnet 4 Magnetic circuit 5 Speaker frame (frame)
6 Voice coil bobbin 7 Voice coil 8 Diaphragm (first diaphragm)
8a Inner periphery of diaphragm 8b Outer periphery of diaphragm 9 Edge 9a Outer periphery of edge 9b Inner periphery of edge 10 Damper 10a Outer periphery of damper 10b Inner periphery of damper 11 Center cap portion 12 Lead wire 13 Hole 14 Input terminal portion 21 , 22 Plate 31 Magnet 32 Magnet (Reverse polarity)
51 Rear flat portion 52 Cone-shaped portion 53 Flat portion 54 Flat portion 55 Flange 81 Inner diaphragm portion 82 Outer diaphragm portion 100 Speaker device 110 Sub cone (second diaphragm)

Claims (8)

An inner peripheral edge is connected to the voice coil bobbin, an outer peripheral edge is connected to the frame via an edge, a top is formed between the inner peripheral edge and the outer peripheral edge, and the inner peripheral edge and the outer peripheral edge are compared to the top part. A first diaphragm formed in a shape located on the acoustic radiation side,
A speaker device comprising: an inner peripheral edge connected to the voice coil bobbin; and a cone-shaped second diaphragm that is located on an acoustic radiation side of the first diaphragm and that is open on the acoustic radiation side.   2. The speaker device according to claim 1, wherein an outer peripheral edge of the second diaphragm is located radially inward from the top of the first diaphragm. A center cap portion covering the sound emitting side end of the voice coil bobbin;
The speaker device according to claim 1, wherein the center cap portion is formed in a convex shape or a concave shape on the acoustic radiation side.   The speaker device according to claim 3, wherein the center cap portion and the second diaphragm are integrally formed.   5. The speaker device according to claim 1, further comprising an internal magnet type magnetic circuit that drives a voice coil disposed on the voice coil bobbin. 6.   The cross-sectional shape from the top of the first diaphragm to the inner peripheral edge is formed in a convex shape toward the acoustic radiation side, and the cross-sectional shape from the top to the outer peripheral edge of the first diaphragm is substantially linear or The speaker device according to claim 1, wherein the speaker device is formed in a convex shape on the acoustic radiation side.   The length of the said 1st diaphragm along the radial direction from the said inner periphery to the said top part is shorter than the length along the radial direction from the said top part to the said outer periphery, The Claim 1 characterized by the above-mentioned. The speaker device according to claim 5.   The diameter of the outer periphery of the first diaphragm is not more than four times the height of the outer periphery of the diaphragm. The speaker device according to any one of the above.

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