WO2012120806A1 - スピーカとそのスピーカを用いた電子機器 - Google Patents
スピーカとそのスピーカを用いた電子機器 Download PDFInfo
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- WO2012120806A1 WO2012120806A1 PCT/JP2012/001219 JP2012001219W WO2012120806A1 WO 2012120806 A1 WO2012120806 A1 WO 2012120806A1 JP 2012001219 W JP2012001219 W JP 2012001219W WO 2012120806 A1 WO2012120806 A1 WO 2012120806A1
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- WIPO (PCT)
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- diaphragm
- voice coil
- speaker
- coil bobbin
- resonance mode
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
- H04R7/12—Non-planar diaphragms or cones
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
- H04R9/02—Details
- H04R9/04—Construction, mounting, or centering of coil
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
- H04R9/06—Loudspeakers
Definitions
- the present invention relates to a speaker and an electronic device using the speaker, and more particularly to a speaker that is reduced in thickness.
- Speaker units used in flat-screen televisions are reduced in width and thickness by so-called narrower frames, such as thinner televisions and thinner housings around the display. Is required. At the same time, there is a demand for higher sound quality with higher screen quality.
- FIGS. 15A to 15C A conventional track-type elongated speaker 10 used in a flat-screen television will be described with reference to FIGS. 15A to 15C.
- FIG. 15A shows a top view of a conventional speaker 10 having a track-shaped elongated structure
- FIG. 15B shows a cross-sectional view along A-A ′ shown in FIG. 15A
- FIG. 15C shows a cross-sectional view along B-B ′ shown in FIG. 15A.
- a conventional track-type elongated speaker 10 includes a diaphragm 1, an edge 2, a voice coil bobbin 3, a voice coil 4, a plate 5, a magnet 6, a yoke 7, And a frame 8.
- a planar shape viewed from the vibration direction has a long side and a short side, a cross-sectional shape in the short side direction is a hollow circular shape, and both ends in the long side direction are a hollow 1/4 spherical shape.
- the outer periphery of the edge 2 is fixed to the frame 8.
- the voice coil bobbin 3 is bonded to the outer periphery of the diaphragm 1 and applies a force to the diaphragm 1.
- the voice coil 4 is supported by the voice coil bobbin 3 so as to be disposed in the magnetic gap G of the magnetic circuit.
- the plate 5, the magnet 6, and the yoke 7 constitute an inner magnet type magnetic circuit.
- the inner magnet type magnetic circuit generates a magnetic flux in a magnetic gap G formed between the inner walls of the plate 5 and the yoke 7.
- the plate 5 is fixed to the upper surface of the magnet 6, and the magnet 6 is fixed to the bottom surface of the yoke 7.
- the plate 5, the magnet 6, and the yoke 7 are arranged so that the longitudinal axis of the diaphragm 1 coincides with the central axis thereof.
- the frame 8 is fixed to the lower side of the outer end portion of the edge 2. It is also fixed to the bottom surface of the magnetic circuit.
- a driving force is generated in the voice coil 4 due to the applied current and a magnetic field generated in the magnetic gap G.
- the generated driving force is transmitted to the diaphragm 1 via the voice coil bobbin 3. Due to the generated driving force, the diaphragm 1, the voice coil bobbin 3, and the voice coil 4 perform the same vibration motion. And when the diaphragm 1 vibrates, a sound is radiated
- the natural vibration is determined by the length in the longitudinal direction.
- a mode occurs.
- a peak dip occurs in an important voice band in terms of sound pressure frequency characteristics, which may lead to deterioration of sound quality.
- the conventional speaker 10 uses a long voice coil bobbin 3 and a voice coil 4 whose planar shape as viewed from the vibration direction is a track shape, and drives the entire longitudinal direction of the diaphragm.
- an object of the present invention is to increase the frequency of the vibration mode and suppress the resonance to further widen the band.
- a speaker includes a cylindrical diaphragm that is closed at both ends, an edge that supports the diaphragm so as to vibrate, and a voice that is wound around a voice coil and connected to the diaphragm.
- the diaphragm may have a circular cross-sectional shape in the short direction.
- each of the diaphragms includes a first diaphragm configured by an arc part having a semicircular cross-sectional shape in a lateral direction, and a flange part protruding radially outward from both ends of the arc part;
- the second diaphragm may be formed by joining the flange portions.
- both ends of the diaphragm may have a hemispherical shape that bulges outward in the longitudinal direction.
- the speaker may include two voice coil bobbins.
- the two voice coil bobbins may be mounted symmetrically with respect to the longitudinal center of the diaphragm and at a position of a node of the first resonance mode of the diaphragm.
- the mounting position of the first voice coil bobbin includes a position of 0.224, and the second voice coil bobbin
- the attachment position may include a position of 0.776.
- the speaker may include four voice coil bobbins.
- the four voice coil bobbins may be mounted symmetrically with respect to the longitudinal center of the diaphragm and at the nodes of the primary resonance mode and the secondary resonance mode of the diaphragm.
- the mounting position of the first voice coil bobbin includes a position of 0.113, and the second voice coil bobbin
- the mounting position includes a position of 0.37775
- the mounting position of the third voice coil bobbin includes a position of 0.62225
- the mounting position of the fourth voice coil bobbin includes a position of 0.877. Good.
- the speaker may include two voice coil bobbins.
- the two voice coil bobbins are symmetrical with respect to the longitudinal center of the diaphragm, and the position of the node of the first resonance mode and the position of the node of the second resonance mode of the diaphragm You may attach to the position of between.
- the mounting position of the first voice coil bobbin includes a position of 0.332, and the second voice coil bobbin
- the attachment position may include a position of 0.668.
- the diaphragm may have a through hole at a position where the voice coil bobbin is attached.
- the voice coil bobbin may be attached to the diaphragm by being inserted through the through hole.
- An electronic device includes a speaker.
- the speaker has a cylindrical diaphragm whose both ends are closed, an edge that supports the diaphragm so as to vibrate, a voice coil bobbin around which a voice coil is wound and connected to the diaphragm, And a magnetic circuit for driving the voice coil.
- the rigidity in the longitudinal direction of the diaphragm can be improved by adopting the cylindrical diaphragm having both ends closed. As a result, there is an effect that the frequency of the vibration mode in the longitudinal direction can be increased.
- FIG. 1A is a top view of the diaphragm according to the first embodiment.
- 1B is a cross-sectional view in the A-A ′ direction of the diaphragm in the first embodiment.
- FIG. 1C is a sectional view of the diaphragm in the B-B ′ direction in the first embodiment.
- FIG. 2A is a hollow semicircular cross-sectional model diagram for calculating the radius of rotation.
- FIG. 2B is a cross-sectional model diagram of a hollow circle for calculating a turning radius.
- FIG. 3 is a calculated value table of the secondary moment, the radius of rotation, and the cross-sectional area of each of the cross-sectional shapes of the hollow circle and the hollow semi-circle.
- FIG. 1A is a top view of the diaphragm according to the first embodiment.
- 1B is a cross-sectional view in the A-A ′ direction of the diaphragm in the first embodiment.
- FIG. 1C is
- FIG. 4 is a diagram illustrating the analysis result of the resonance frequency of the natural vibration mode by the FEM incorporating the diaphragm in the first embodiment and the actual shape model of the conventional diaphragm.
- FIG. 5A is a top view of the speaker according to the second embodiment.
- FIG. 5B is a cross-sectional view of the speaker in the A-A ′ direction according to the second embodiment.
- FIG. 5C is a cross-sectional view of the speaker in the B-B ′ direction according to the second embodiment.
- FIG. 5D is a cross-sectional view in the C-C ′ direction of the speaker according to the second embodiment.
- FIG. 6A is a diagram showing characteristics in the case of two-point drive for controlling the primary resonance mode.
- FIG. 6A is a diagram showing characteristics in the case of two-point drive for controlling the primary resonance mode.
- FIG. 6B is a diagram illustrating characteristics in the case of two-point driving for controlling the secondary resonance mode.
- FIG. 6C is a diagram illustrating characteristics in the case of four-point driving for controlling both the first and second resonance modes.
- FIG. 7A is a top view of the speaker according to the third embodiment.
- FIG. 7B is a cross-sectional view in the A-A ′ direction of the speaker according to the third embodiment.
- FIG. 7C is a cross-sectional view of the speaker in the B-B ′ direction according to the third embodiment.
- FIG. 7D is a cross-sectional view in the C-C ′ direction of the speaker according to the third embodiment.
- FIG. 8A is a top view of the speaker according to the fourth embodiment.
- FIG. 8B is a cross-sectional view of the speaker in the A-A ′ direction in the fourth embodiment.
- FIG. 8C is a cross-sectional view of the speaker in the B-B ′ direction according to the fourth embodiment.
- FIG. 8D is a cross-sectional view of the speaker in the C-C ′ direction according to the fourth embodiment.
- FIG. 9A is a top view of the speaker used in the simulation for changing the drive position.
- 9B is a cross-sectional view of the loudspeaker in FIG. 9A in the A-A ′ direction.
- FIG. 9C is a cross-sectional view of the speaker in the B-B ′ direction in FIG. 9A.
- FIG. 10 is a diagram for explaining the peak dip due to the resonance mode of the sound pressure frequency characteristic obtained by simulation.
- FIG. 11 is a diagram illustrating a deviation width of the peak dip depending on the resonance mode with respect to the driving position.
- FIG. 12 is a diagram showing a simulation analysis result of sound pressure frequency characteristics when driven at a position where the first resonance mode is suppressed and a position where the second resonance mode is suppressed.
- FIG. 13 is a diagram illustrating a difference in sound pressure frequency characteristics due to a difference in the fixing condition of the voice coil bobbin 203 to the diaphragm 201.
- FIG. 14 is an external view of a television receiver equipped with a speaker according to Embodiment 2 of the present invention.
- FIG. 15A is a top view of a conventional speaker.
- FIG. 15B is a cross-sectional view of the conventional speaker in the A-A ′ direction.
- FIG. 15C is a cross-sectional view of the conventional speaker in the B-B ′ direction.
- Patent Document 1 As a prior art document related to the invention of this application, for example, Patent Document 1 is known.
- the linear part of the voice coil bobbin resonates at several specific frequencies (resonance frequencies), and the direction perpendicular to the vibration direction of the diaphragm (the magnetic circuit that drives the voice coil bobbin is within the magnetic gap). Vibrates in the direction of magnetic flux). As the straight line portion becomes longer, the resonance frequency becomes lower and the resonance amplitude also increases.
- an inner surface of the voice coil bobbin has a space between surfaces facing each other with respect to the minor axis direction of the diaphragm, parallel to the vibration direction of the diaphragm, and the facing surface. The effect is suppressed by attaching a thin plate-like connecting member that stretches at a right angle.
- a large magnet is required to drive the elongated voice coil.
- a length corresponding to the length of the voice coil in the longitudinal direction is required.
- Embodiments 1 to 4 of the present invention a speaker that effectively prevents a peak dip from occurring in an important voice band in terms of sound pressure frequency characteristics by an approach different from that of Patent Document 1 described above.
- the structure will be described in detail.
- FIG. 1A is a top view of a diaphragm used in the speaker in this embodiment
- FIG. 1B is a cross-sectional view taken along the line A-A ′ shown in FIG. 1A
- FIG. 1C is a cross-sectional view taken along the line B-B ′ shown in FIG.
- the diaphragm 100 has a structure in which a planar shape seen from the vibration direction has a long side and a short side, a cross-sectional shape in the short side direction is a hollow circular shape, and both ends in the longitudinal direction are hollow hemispherical shapes. Have. In other words, the diaphragm 100 has a bottomed cylindrical shape in which both ends are closed. Further, the cross-sectional shape of the diaphragm 100 in the short direction is a perfect circle. Furthermore, both ends of the diaphragm 100 have a semicircular shape that bulges outward in the longitudinal direction.
- the material of the diaphragm 100 is preferably suitable for thinning and lightweight. For example, paper or a polymer film is optimal, but a lightweight and highly rigid metal foil such as aluminum or titanium may be used.
- the diaphragm 100 is provided with a diaphragm pasting portion (flange portion) 102 at a terminal portion having a semicircular cross section in the short direction, and the first and second long and narrow vibrations having a track shape as viewed from above.
- Two plates 101a and 101b are bonded together.
- each of the first and second diaphragms 101a and 101b includes an arc portion having a semicircular cross-sectional shape in the short direction (a portion having a semicircular cross-sectional shape in the short direction), and an arc portion. And flange portions projecting radially outward from both ends.
- the diaphragm 100 is formed by joining the first and second diaphragms 101a and 101b with flange portions.
- the effect of changing the cross-sectional shape in the short direction from the conventional hollow semicircular shape to the hollow circular shape will be described below from the viewpoints of theory and simulation. First, it explains from the viewpoint of theory.
- Equation 1 shows a resonance frequency equation of a vibration mode of a rod having free ends.
- l is the length of the rod
- ⁇ is the density
- Q is the Young's modulus of the material
- K is the radius of rotation.
- Equation 1 the rotation radius K varies depending on the cross-sectional shape.
- FIG. 2A shows a hollow semicircular cross-sectional shape
- FIG. 2B shows a hollow circular cross-sectional shape.
- the radius of rotation for each cross-sectional shape will be described with reference to FIGS. 2A and 2B.
- the sectional moment of the figure of the hollow section such as a pipe or tunnel is obtained by subtracting the sectional moment of the hollow figure from the sectional moment of the outer figure.
- the position of the centroid of the outer graphic is different from the position of the centroid of the inner graphic with respect to the reference axis for obtaining the sectional moment.
- the thickness of the diaphragm is very thin, so that the radius of the outer semicircle and the radius of the inner semicircle can be considered to be substantially equal.
- the cross-sectional secondary moment of the hollow semicircular shape can be considered as a difference between the cross-sectional secondary moments of the outer and inner semicircles.
- Formula 2 shows the cross-sectional secondary moment of a semicircular shape that is not hollow
- Formula 3 shows the cross-sectional secondary moment of the hollow semicircular shape
- Formula 4 shows the cross-sectional area.
- rsemi represents the radius of a non-hollow semicircle
- R represents the radius of the outer semicircle
- r represents the radius of the inner semicircle.
- the turning radius of the hollow semicircular section is given by Equation 5.
- Equation 6 shows the moment of inertia of the cross section having a hollow circular shape
- Equation 7 shows the radius of rotation
- Equation 8 shows the sectional area
- FIG. 3 shows the secondary moment, the radius of rotation, and the cross-sectional area of each of the cross-sectional shapes calculated using Equations 3 to 8 in a hollow semicircular shape and a hollow circular shape.
- Equation 1 From Equation 1, it can be seen that when the rod length and material constant are the same, the change in resonance frequency due to the change in cross-sectional shape is proportional to the radius of rotation. Moreover, the rigidity (bending rigidity) of the bar is represented by the product of the Young's modulus of the bar material and the moment of inertia of the cross section. That is, it can be seen that the rigidity of the rod is proportional to the cross-sectional second moment.
- the radius of rotation becomes about 1.9 times and the secondary moment of section becomes about 7.2 times.
- the resonance frequency is increased by about 1.9 times, and the rigidity is improved by about 7.2 times.
- FIG. 4 shows the result of analyzing the resonance frequency of the natural vibration mode according to)).
- the resonance frequency (theoretical value) is the result calculated using Equation 1.
- Fig. 4 shows that the theoretical calculation values and the simulation analysis values are in good agreement. It can also be seen that the resonance frequency of the diaphragm 100 having a hollow circular cross section is about twice as high as that of the diaphragm 1 having a hollow semicircular cross section. From the resonance frequency change of the simulation result, the change in rigidity due to the change in the cross-sectional shape of the diaphragm from the hollow semicircular shape to the hollow circular shape is calculated backward.
- the resonance frequency is proportional to the radius of rotation.
- the turning radius is the square root of the quotient of the sectional moment of inertia and the sectional area
- the sectional moment of inertia is proportional to the product of the square of the turning radius and the sectional area. Therefore, from FIG. 4, when the cross-sectional shape of the diaphragm is changed from a semicircular shape to a circular shape, the change in the radius of rotation is about twice, and the cross-sectional area is also doubled. As a result, it can be seen that the rigidity is about 8 times.
- the rigidity in the longitudinal direction of the diaphragm 100 can be improved and the resonance frequency of the mode can be increased. For this reason, the number of resonance frequencies that have an influence on an important voice band can be reduced.
- the diaphragm 100 having a semicircular cross-sectional shape in the short direction has been described.
- the rigidity can be further increased by making the cross-sectional shape an oval shape.
- it may be a hollow trapezoid or a hollow polyhedron.
- the cross-sectional shape in the short direction is not particularly limited as long as the diaphragm in the present embodiment has a cylindrical shape in which both end surfaces in the longitudinal direction are closed.
- the example in which both ends of the diaphragm 100 bulge outward in the longitudinal direction is shown, but the present invention is not limited to this.
- the shape of both end faces in the longitudinal direction of the diaphragm may be flat or other shapes, for example.
- FIG. 5A is a top view of the speaker 200 in this embodiment
- FIG. 5B is a cross-sectional view taken along line AA ′ shown in FIG. 5A
- FIG. 5C is a cross-sectional view taken along line BB ′ shown in FIG. 5A
- FIG. CC 'sectional drawing shown to a) is shown.
- the speaker 200 includes a diaphragm 201, an edge 202, a voice coil bobbin 203, a voice coil 204, a plate 205, a magnet 206, a yoke 207, Frame 208.
- the diaphragm 201 has substantially the same configuration as that of the diaphragm 100 except that the through-hole 209 that penetrates in the vibration direction of the diaphragm 201 and through which the voice coil bobbin 203 is inserted is formed in two places. .
- the outer periphery of the edge 202 is fixed to the frame 208.
- the cross section of the edge 202 is a hollow semicircle.
- the edge 202 is desirably made of a rubber material such as an elastomer or SBR, for example, in order to lower the lower limit of the low-frequency speaker 200 as the material.
- a rubber material such as an elastomer or SBR, for example, in order to lower the lower limit of the low-frequency speaker 200 as the material.
- SBR elastomer
- the assembly of the edge 202 and the diaphragm 201 for example, they may be bonded after being molded separately, or may be integrally formed by insert molding or the like.
- the voice coil bobbin 203 is inserted into the through hole 209 of the diaphragm 201 and bonded to the inner wall surface of the through hole 209 to apply force to the diaphragm 201.
- the planar shape of the voice coil bobbin 203 when viewed from the vibration direction has a semicircular or elliptical shape at the end in the longitudinal direction, and has a track shape as a whole.
- the material of the voice coil bobbin 203 is, for example, paper, aluminum foil, or a polymer resin film such as polyimide, which is molded into a desired shape.
- the voice coil 204 is wound (wound) on the voice coil bobbin 203 and supported by the diaphragm 201 so as to be disposed in the magnetic gap G of the magnetic circuit.
- the planar shape of the voice coil 204 when viewed from the vibration direction has a semicircular or elliptical shape at the end in the longitudinal direction, and has a track shape as a whole.
- Two voice coil bobbins 203 to which the voice coil 204 is fixed are disposed at positions symmetrical with respect to the center in the longitudinal direction of the speaker 200.
- the material of the voice coil 204 is a winding of a conductor such as copper or aluminum.
- the plate 205, the magnet 206, and the yoke 207 constitute an outer magnet type magnetic circuit.
- the outer magnet type magnetic circuit generates a magnetic flux in the magnetic gap G formed between the inner walls of the plate 205 and the yoke 207.
- the plate 205 is fixed to the upper surface of the magnet 206, and the magnet 206 is fixed to the bottom surface of the yoke 207.
- the outer magnetic type magnetic circuit is fixed to the frame 208.
- the outer magnet type magnetic circuit and the voice coil bobbin 203 to which the voice coil 204 is fixed are located at two positions symmetrical to the center in the longitudinal direction of the speaker 200 so that the center positions viewed from the vibration direction coincide with each other. Be placed.
- the magnet 206 is composed of a rare earth magnet such as a ferrite magnet or a neodymium magnet, a samarium iron-based bond magnet, or the like according to the target sound pressure, shape, or the like.
- the speaker 200 configured as described above is attached to, for example, a thin television receiver 600. As shown in FIG. 15, the television receiver 600 is very thin, and the outer frame portion of the display screen on which the speaker 200 is installed is very narrow. And the speaker 200 which concerns on a present Example is suitable for installing in such a place. The same applies to the following embodiments.
- the frame 208 of the speaker 200 in this embodiment is fastened with a bolt to the frame 610 of the television receiver 600 as shown in FIG. 5B.
- the fixing method of the frames 208 and 610 is not limited to this, and a method such as adhesion may be adopted.
- the speaker of Example 1 is driven by one voice coil (not shown) with the center of the diaphragm 100 as a driving point.
- This structure is sufficient when there is no resonance of the diaphragm 100 within the operating frequency band.
- the band is secured by the structure that increases the rigidity of the diaphragm 100.
- it is necessary to suppress the generated resonance mode.
- the first resonance mode that occurs first is suppressed, and a flat characteristic is realized up to the next second resonance mode.
- two voice coils 204 are symmetrically arranged at a distance d1 from the center to the left and right. That is, the drive point for controlling the primary resonance mode is provided so as to include the position of the node of the primary resonance mode.
- the resonance state of the vibration plate 201 is substantially the same as the resonance state of the free rod at both ends when the rigidity of the vibration plate 201 is higher than that of the edge 202 and the mass of the edge 202 is light like the vibration plate 201. Therefore, the position of the node of the primary resonance mode in the longitudinal direction of the vibration plate 201 is 0 from one end in the longitudinal direction of the vibration plate 201 when one end in the longitudinal direction of the vibration plate 201 is 0 and the other end is 1. The position corresponds to .224 and the position corresponding to 0.776.
- the voice coil bobbin 203 is positioned at the position corresponding to the node of the primary resonance mode in the longitudinal direction of the vibration plate 201, that is, the position corresponding to 0.224 from one end of the vibration plate 201 in the longitudinal direction. It is fixed at a position corresponding to 776.
- the voice coil bobbin 203 is attached so that the position of the node of the primary resonance mode (that is, the position corresponding to 0.224, 0.776) and the center (center of gravity) position of the voice coil bobbin 203 coincide. Is most desirable. However, it is not always necessary that they exactly match each other, and if the position of the primary resonance mode node is included in the outline of the upper surface of the voice coil bobbin 203 (track shape in FIG. 5A). The effect of this embodiment can be expected. The same applies to the following embodiments.
- a driving force is generated in the voice coil 204 by the applied current and a magnetic field generated in the magnetic gap G.
- the generated driving force is transmitted to the diaphragm 201 via the voice coil bobbin 203. Due to the generated driving force, the diaphragm 201, the voice coil bobbin 203, and the voice coil 204 perform the same vibration motion. And sound is radiated
- FIG. 4 shows that the number of resonance modes affecting the important sound band of the diaphragm 100 of the first embodiment is two.
- the diaphragm 201 is driven at the node position of the first primary resonance mode in the first, so the first resonance mode is suppressed, and the next secondary resonance mode is reproduced flatly. be able to.
- FIG. 6A shows the speaker characteristics of this example calculated by FEM analysis.
- the vertical axis represents SPL and the horizontal axis represents frequency.
- the speaker 200 of the present embodiment can reproduce from Fo (800 Hz) to 4.5 kHz.
- the reason why the frequency is lower than the resonance frequency of FIG. 4 is that the resonance frequency is lowered by the edge 202 and the resonance frequency is lowered by the additional mass of the voice coil 204.
- FIG. 7A is a top view of the speaker 300 in this embodiment
- FIG. 7B is a cross-sectional view along AA ′ shown in FIG. 7A
- FIG. 7C is a cross-sectional view along BB ′ shown in FIG. 7A
- FIG. CC 'sectional drawing shown is shown. Since the speaker 300 is symmetrical, only the left half of the center line is shown in FIGS. 7A and 7B.
- the speaker 300 in this embodiment includes a diaphragm 301, an edge 302, a voice coil bobbin 303, a voice coil 304, a plate 305, a magnet 306, a yoke 307, And a frame 308.
- the diaphragm 301 has substantially the same configuration as the diaphragm 100, but has through holes 309 that penetrate the diaphragm 301 in the vibration direction and through which the voice coil bobbin 303 is inserted. Is different.
- the outer periphery of the edge 302 is fixed to the frame 308.
- the cross section of the edge 302 is a hollow semicircle.
- the edge 302 is desirably made of a rubber material such as an elastomer or SBR, for example, in order to lower the low-frequency limit while the thin speaker 300 is used as the material.
- SBR elastomer
- the assembly of the edge 302 and the diaphragm 301 they may be formed separately and then bonded together, or may be integrally formed by insert molding or the like.
- the voice coil bobbin 303 is inserted into the through hole 309 of the diaphragm 301 and is adhered to the inner wall surface of the through hole 309 to apply force to the diaphragm 301.
- the planar shape of the voice coil bobbin 303 when viewed from the vibration direction is a track shape as a whole, with the end in the longitudinal direction being a semicircle or an ellipse.
- the material of the voice coil bobbin 303 is, for example, paper, aluminum foil, or a polymer resin film such as polyimide, which is molded into a desired shape.
- the four voice coil bobbins 303 are fixed in a symmetrical manner with respect to the longitudinal center of the diaphragm 301, two in total.
- the drive positions d2 and d3 of the diaphragm 301 and the voice coil bobbin 303 are positions for controlling both the primary resonance mode and the secondary resonance mode, as will be described later. Prior to the driving point for controlling both, the driving point (node position) for controlling the secondary resonance mode will be described.
- the positions of the nodes of the second resonance mode are 0.0944, 0.3558, 0.6442 from one end in the longitudinal direction of the diaphragm 301 when one end in the longitudinal direction of the diaphragm 301 is 0 and the other end is 1. , 0.9056.
- the voice coil bobbin 303 is fixed to a position corresponding to 0.0944 from one end in the longitudinal direction of the diaphragm 301 and a position corresponding to 0.9056, or 0 from one end in the longitudinal direction of the diaphragm 301. .3558 and a position corresponding to 0.6442.
- the sound pressure frequency characteristic is calculated as shown in FIG. 6B.
- the secondary resonance mode is controlled, the primary resonance mode exists at a lower 1.2 kHz. For this reason, the reproduction band is narrowed. Therefore, in this embodiment, a drive point is provided at a position where both the primary resonance mode and the secondary resonance mode are controlled.
- the driving point is determined as follows.
- ⁇ is the density
- s is the cross-sectional area of the rod
- l is the length of the rod
- ⁇ m (x) and ⁇ m (y) are reference functions representing the vibration state
- ⁇ is the angular velocity
- a condition in which both the primary resonance mode and the secondary resonance mode do not occur is that x1, x2, x3, and x4 satisfy Expression 11. That is, x1, x2, x3, and x4 that satisfy Expression 11 may be obtained as driving points for controlling both the primary resonance mode and the secondary resonance mode.
- x1, x2, x3, and x4 that satisfy Expression 11 may be obtained as driving points for controlling both the primary resonance mode and the secondary resonance mode.
- an asymmetric mode does not occur. Therefore, here, except for the asymmetric mode, they are referred to as a primary resonance mode and a secondary resonance mode in order from the low-order mode.
- FIG. 6C shows the results of speaker characteristics of this example by FEM simulation analysis.
- FIG. 6C it can be seen that both the primary resonance mode and the secondary resonance mode are reduced.
- Example 4 From the above results, it is best to apply a four-point drive that controls both the primary resonance mode and the secondary resonance mode. However, if four voice coils are used, four magnetic circuits are also required, which increases the material cost of the magnet. Therefore, it is necessary to limit the number of voice coils to be used to two, and to determine the driving position where the deviation width of the peak dip due to both resonance modes can be minimized to the same extent.
- the speaker 400 according to the fourth embodiment is designed to moderately suppress both the primary resonance and the secondary resonance while achieving two driving points, thereby achieving wideband reproduction.
- FIG. 8A is a top view of the speaker 400 in this embodiment
- FIG. 8B is a cross-sectional view taken along line AA ′ shown in FIG. 8A
- FIG. 8C is a cross-sectional view taken along line BB ′ shown in FIG. 8A
- FIG. CC 'sectional drawing shown is shown. Since the speaker 400 is symmetrical, only the left half of the center line is shown in FIGS. 8A and 8B.
- the basic configuration of the speaker 400 of this embodiment is the same as that of the second embodiment, but the driving position d4 of the voice coil 404 is different from that of the second embodiment.
- the speaker 400 in this embodiment includes a diaphragm 401, an edge 402, a voice coil bobbin 403, a voice coil 404, a plate 405, a magnet 406, a yoke 407, Frame 408.
- the diaphragm 401 has substantially the same configuration as that of the diaphragm 100, except that through holes 409 that penetrate in the vibration direction of the diaphragm 401 and through which the voice coil bobbin 403 is inserted are formed in two places.
- the drive position d4 is installed at a position where both the primary resonance mode and the secondary resonance mode in the longitudinal direction of the diaphragm 401 are appropriately controlled.
- the positions are the positions of the nodes of the primary resonance mode of the diaphragm 401 (positions of 0.224 and 0.776 when the longitudinal length of the diaphragm is 1, and the center of the secondary resonance mode).
- the middle point of the position of the side node (the position of 0.355 and 0.645 when the longitudinal length of the diaphragm is 1) or its vicinity (0.29 when the longitudinal direction of the diaphragm is 1) (Position 0.71).
- a speaker 500 shown in FIGS. 9A to 9C includes a diaphragm 501, an edge 502, a voice coil bobbin 503, a voice coil 504, a plate 505, a magnet 506, a yoke 507, and a frame 508.
- the voice coil bobbin 503 is attached to the center of the diaphragm 501 in the longitudinal direction.
- Deviations of the peak dip appearing on the sound pressure frequency characteristics by the primary resonance mode and the secondary resonance mode in the longitudinal direction are P1 and P2, respectively.
- the sound pressure frequency characteristic is simulated and analyzed while moving the voice coil bobbin 503 from the center of the diaphragm 501 toward the end in the longitudinal direction, and the sound pressure deviations P1 and P2 at the respective positions are obtained. That is, a simulation analysis of sound pressure frequency characteristics with respect to changes in the position of the driving point was performed.
- Fig. 11 shows the deviation width of the peak dip depending on the resonance mode with respect to the drive position.
- the horizontal axis indicates the ratio of the distance from one end in the longitudinal direction when the entire length of the vibration plate 401 in the longitudinal direction is 1.
- the center 0.5 of the graph indicates the center position of the vibration plate 401 in the longitudinal direction.
- the solid line in the graph indicates the peak dip deviation P1 due to the influence of the primary resonance mode, and the broken line indicates the peak dip deviation P2 due to the influence of the secondary resonance mode.
- the vertical lines in FIG. 11 indicate the positions of the nodes of the first and second resonance modes calculated from the resonance state of the rods having free ends.
- the drive position where the deviation width is minimized is slightly deviated from the position of the node in the first resonance mode and the position of the node in the second resonance mode calculated from the resonance state of the free rod at both ends. It can be seen that it exists at a position in the vicinity. From the graph, it can be seen that the position where the first resonance mode is suppressed is 0.760, and the position where the second resonance mode is suppressed is 0.620.
- FIG. 7 also shows that the peak dip deviation width due to both resonance modes can be reduced to the same extent at the 0.668 position.
- the position where the deviation width of the peak dip due to both resonance modes can be reduced to the minimum deviation width to the same extent is the position of the node of the primary resonance mode and the node inside the secondary resonance mode.
- the position is 0.668 when the diaphragm length is 1.
- the diaphragm 401 is driven between the position of the node in the first resonance mode and the position of the node inside the second resonance mode, so that the first resonance mode
- the deviation width of the peak dip due to the second resonance mode can be reduced to the minimum deviation width to the same extent.
- FIG. 12 shows a simulation analysis result of sound pressure frequency characteristics when driven at the aforementioned position. From FIG. 12, the deviation width of the peak dip in the primary resonance mode and the secondary resonance mode is both reduced to the same extent, and a flat sound pressure frequency characteristic is approached.
- the resonance at can be controlled. For this reason, the effect that a further flat sound pressure frequency characteristic is realizable is acquired.
- FIG. 13 shows the difference in the sound pressure frequency characteristics due to the difference in the fixing conditions of the voice coil bobbin 403 to the diaphragm 401.
- the speaker according to each embodiment of the present invention can be easily slimmed and thinned, the speaker is not limited to the thin television receiver 600 shown in FIG. 15, but is applied to an electronic device such as a mobile phone or a PDA. Is also effective. That is, the electronic device is configured to include the speaker according to each embodiment of the present invention and a housing that holds the speaker inside.
- the speaker diaphragm of the present invention is useful as a speaker capable of suppressing split resonance while having an elongated structure.
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- Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
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Abstract
Description
以下、本発明の実施例1におけるスピーカに用いられる振動板について図面を参照しながら説明する。
以下、本発明の実施例2では、実施例1の振動板100の最適な駆動方法について図面を参照しながら説明する。なお、実施例1、2との共通点の詳しい説明は省略し、相違点を中心に説明する。
以下、本発明の実施例3について図面を参照しながら説明する。なお、実施例1、2との共通点の詳しい説明は省略し、相違点を中心に説明する。
x2=0.37775 ・・(式15)
x3=(1-x2)=0.62225 ・・(式16)
x4=(1-x1)=0.8770 ・・(式17)
以上より、式14~式17を満たすx1~x4により示される4点が駆動点となる。
上記結果から、第1次共振モードと第2次共振モードとの両方を制御する4点駆動を適用すれば最もよい。しかしながら、ボイスコイルを4個使用すれば、磁気回路も同様に4個必要となり、マグネットの材料コストが増加してしまう。そこで、使用するボイスコイルを2個に限定し、両共振モードによるピークディップの偏差幅を共に同程度まで最小限に抑えることができる駆動位置を見極める必要がある。本実施例4のスピーカ400は、駆動点を2つとしながら第1次共振と第2次共振との両方を適度に抑制し、広帯域再生を図るものである。
2,202,302,402,502 エッジ
3,203,303,403,503 ボイスコイルボビン
4,204,304,404,504 ボイスコイル
5,205,305,405,505 プレート
6,206,306,406,506 マグネット
7,207,307,407,507 ヨーク
8,208,308,408,508,610 フレーム
10,200,300,400,500 スピーカ
101a 第1の振動板
101b 第2の振動板
102 振動板張り合わせ部
209,309,409,509 貫通孔
600 テレビジョン受像機
Claims (12)
- 両端が閉止されている筒形状の振動板と、
前記振動板を振動可能に支持するエッジと、
ボイスコイルが巻回され、前記振動板に接続されるボイスコイルボビンと、
前記ボイスコイルを駆動させるための磁気回路とを備える
スピーカ。 - 前記振動板は、短手方向の断面形状が円形状である
請求項1に記載のスピーカ。 - 前記振動板は、各々が、短手方向の断面形状が半円形状の円弧部と、前記円弧部の両端から径方向外側に突出するフランジ部とで構成される第1の振動板及び第2の振動板を、前記フランジ部同士を結合することによって形成される
請求項2に記載のスピーカ。 - 前記振動板の両端は、長手方向の外向きに膨出する半球形状である
請求項1~3のいずれか1項に記載のスピーカ。 - 前記スピーカは、2つの前記ボイスコイルボビンを備え、
2つの前記ボイスコイルボビンは、前記振動板の長手方向の中心に対して対称で、且つ前記振動板の第1次共振モードの節の位置に取り付けられる
請求項1~4のいずれか1項に記載のスピーカ。 - 前記振動板の長手方向の一端を0、他端を1としたとき、
第1の前記ボイスコイルボビンの取り付け位置は、0.224の位置を含み、
第2の前記ボイスコイルボビンの取り付け位置は、0.776の位置を含む
請求項5に記載のスピーカ。 - 前記スピーカは、4つの前記ボイスコイルボビンを備え、
4つの前記ボイスコイルボビンは、前記振動板の長手方向の中心に対して対称で、且つ前記振動板の第1次共振モード及び第2次共振モードの節の位置に取り付けられる
請求項1~4のいずれか1項に記載のスピーカ。 - 前記振動板の長手方向の一端を0、他端を1としたとき、
第1の前記ボイスコイルボビンの取り付け位置は、0.113の位置を含み、
第2の前記ボイスコイルボビンの取り付け位置は、0.37775の位置を含み、
第3の前記ボイスコイルボビンの取り付け位置は、0.62225の位置を含み、
第4の前記ボイスコイルボビンの取り付け位置は、0.877の位置を含む
請求項7に記載のスピーカ。 - 前記スピーカは、2つの前記ボイスコイルボビンを備え、
2つの前記ボイスコイルボビンは、前記振動板の長手方向の中心に対して対称で、且つ前記振動板の第1次共振モードの節の位置と前記第2次共振モードの節の位置との間の位置に取り付けられる
請求項1~4のいずれか1項に記載のスピーカ。 - 前記振動板の長手方向の一端を0、他端を1としたとき、
第1の前記ボイスコイルボビンの取り付け位置は、0.332の位置を含み、
第2の前記ボイスコイルボビンの取り付け位置は、0.668の位置を含む
請求項9に記載のスピーカ。 - 前記振動板は、前記ボイスコイルボビンの取り付け位置に貫通孔を有し、
前記ボイスコイルボビンは、前記貫通孔に挿通されることによって、前記振動板に取り付けられる
請求項1~10のいずれか1項に記載のスピーカ。 - スピーカを備える電子機器であって、
前記スピーカは、
両端が閉止されている筒形状の振動板と、
前記振動板を振動可能に支持するエッジと、
ボイスコイルが巻回され、前記振動板に接続されるボイスコイルボビンと、
前記ボイスコイルを駆動させるための磁気回路とを備える
電子機器。
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JP2012529050A JP6052669B2 (ja) | 2011-03-04 | 2012-02-23 | スピーカとそのスピーカを用いた電子機器 |
US13/643,456 US8879776B2 (en) | 2011-03-04 | 2012-02-23 | Speaker and electronic device using the speaker |
CN201280001275.6A CN102884810B (zh) | 2011-03-04 | 2012-02-23 | 扬声器和使用该扬声器的电子设备 |
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USD729213S1 (en) * | 2013-11-15 | 2015-05-12 | Apple Inc. | Speaker stand |
CN104883649A (zh) * | 2015-06-05 | 2015-09-02 | 歌尔声学股份有限公司 | 振动发声装置 |
CN104883650A (zh) * | 2015-06-05 | 2015-09-02 | 歌尔声学股份有限公司 | 振动发声装置 |
USD793992S1 (en) * | 2015-12-09 | 2017-08-08 | Harman International Industries, Incorporated | Loudspeaker |
USD853356S1 (en) * | 2017-03-26 | 2019-07-09 | Polk Audio, Llc | Audio soundbar speaker |
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JPH0335697A (ja) * | 1989-06-30 | 1991-02-15 | Matsushita Electric Ind Co Ltd | スピーカ |
JPH08265895A (ja) * | 1995-03-22 | 1996-10-11 | Matsushita Electric Ind Co Ltd | スピーカ |
JP2003023695A (ja) * | 2001-07-10 | 2003-01-24 | Sony Corp | スピーカ装置 |
JP2003304591A (ja) * | 2002-04-10 | 2003-10-24 | Matsushita Electric Ind Co Ltd | スピーカ装置 |
JP2006222989A (ja) * | 2006-04-12 | 2006-08-24 | Pioneer Electronic Corp | スピーカ装置 |
JP2008109541A (ja) * | 2006-10-27 | 2008-05-08 | Foster Electric Co Ltd | 平面振動板スピーカ |
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US4782471A (en) * | 1984-08-28 | 1988-11-01 | Commissariat A L'energie Atomique | Omnidirectional transducer of elastic waves with a wide pass band and production process |
DE69535049T2 (de) * | 1994-04-25 | 2007-05-10 | Matsushita Electric Industrial Co., Ltd., Kadoma | Ausgedehnter Lautsprecher |
US5701358A (en) * | 1994-07-05 | 1997-12-23 | Larsen; John T. | Isobaric loudspeaker |
JP3582201B2 (ja) | 1996-01-23 | 2004-10-27 | 松下電器産業株式会社 | スピーカ |
WO2005117489A1 (ja) * | 2004-05-27 | 2005-12-08 | Matsushita Electric Industrial Co., Ltd. | スピーカ |
US7961902B2 (en) * | 2005-05-25 | 2011-06-14 | Pioneer Corporation | Speaker apparatus and manufacturing method thereof |
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2012
- 2012-02-23 JP JP2012529050A patent/JP6052669B2/ja active Active
- 2012-02-23 US US13/643,456 patent/US8879776B2/en active Active
- 2012-02-23 WO PCT/JP2012/001219 patent/WO2012120806A1/ja active Application Filing
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Publication number | Priority date | Publication date | Assignee | Title |
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JPH0335697A (ja) * | 1989-06-30 | 1991-02-15 | Matsushita Electric Ind Co Ltd | スピーカ |
JPH08265895A (ja) * | 1995-03-22 | 1996-10-11 | Matsushita Electric Ind Co Ltd | スピーカ |
JP2003023695A (ja) * | 2001-07-10 | 2003-01-24 | Sony Corp | スピーカ装置 |
JP2003304591A (ja) * | 2002-04-10 | 2003-10-24 | Matsushita Electric Ind Co Ltd | スピーカ装置 |
JP2006222989A (ja) * | 2006-04-12 | 2006-08-24 | Pioneer Electronic Corp | スピーカ装置 |
JP2008109541A (ja) * | 2006-10-27 | 2008-05-08 | Foster Electric Co Ltd | 平面振動板スピーカ |
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US8879776B2 (en) | 2014-11-04 |
CN102884810A (zh) | 2013-01-16 |
JP6052669B2 (ja) | 2016-12-27 |
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