WO2021131705A1 - Speaker and vehicle - Google Patents

Speaker and vehicle Download PDF

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Publication number
WO2021131705A1
WO2021131705A1 PCT/JP2020/045865 JP2020045865W WO2021131705A1 WO 2021131705 A1 WO2021131705 A1 WO 2021131705A1 JP 2020045865 W JP2020045865 W JP 2020045865W WO 2021131705 A1 WO2021131705 A1 WO 2021131705A1
Authority
WO
WIPO (PCT)
Prior art keywords
sound
speaker
acoustic member
opening
emitting surface
Prior art date
Application number
PCT/JP2020/045865
Other languages
French (fr)
Japanese (ja)
Inventor
潤弥 松岡
Original Assignee
ヤマハ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ヤマハ株式会社 filed Critical ヤマハ株式会社
Publication of WO2021131705A1 publication Critical patent/WO2021131705A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R11/00—Arrangements for holding or mounting articles, not otherwise provided for
    • B60R11/02—Arrangements for holding or mounting articles, not otherwise provided for for radio sets, television sets, telephones, or the like; Arrangement of controls thereof
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
    • 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

Definitions

  • the present invention relates to a speaker and a vehicle.
  • Patent Document 1 discloses a sounding unit that emits sound by vibrating a diaphragm housed in a housing.
  • the housing has a case body provided in front of the diaphragm.
  • a space is formed between the case main body and the diaphragm, and the case main body is provided with a plurality of openings.
  • the space and the opening constitute a Helmholtz resonator.
  • the sound pressure of the fundamental frequency in the sound emitted from the diaphragm is increased by the Helmholtz resonator.
  • in-vehicle speakers are arranged inside a panel such as an instrument panel or a head console.
  • the speaker may be covered with a panel from a design point of view or the like.
  • the panel becomes an obstacle that hinders the propagation of the sound from the speaker, and the high-frequency sound from the speaker is attenuated.
  • the unit described in Patent Document 1 cannot suitably enhance the high-frequency sound. Therefore, the unit described in Patent Document 1 has a problem that it becomes difficult to hear the sound from the speaker when it is used for in-vehicle use or the like.
  • an object of the present invention is to make it easier to hear the sound from the speaker even in an environment where there is an obstacle at a position facing the front of the speaker.
  • the speaker according to a preferred embodiment of the present invention is based on a vibrating plate having a sound emitting surface for emitting sound and an audio signal indicating sound limited to a predetermined frequency band.
  • An acoustic member having a driving unit for driving a vibrating plate and at least one opening, and arranged so as to form a space forming a Helmholtz resonator together with the at least one opening between the sound emitting surface and the sound emitting surface.
  • the Helmholtz resonator enhances the components within the predetermined frequency band among the frequency components of the sound from the sound emitting surface, and attenuates the components exceeding the predetermined frequency band.
  • the speaker includes a sound emitting unit including a cone-shaped diaphragm having a sound emitting surface for emitting sound, and the sound emitting unit in a state where the sound emitting surface is exposed to an external space.
  • a sound emitting unit including a cone-shaped diaphragm having a sound emitting surface for emitting sound, and the sound emitting unit in a state where the sound emitting surface is exposed to an external space.
  • the vehicle according to a preferred embodiment of the present invention has a speaker according to any of the above-mentioned aspects.
  • FIG. 5 is a cross-sectional view taken along the line A1-A1 in FIG. It is a top view of the acoustic member in 2nd Embodiment.
  • FIG. 7 is a cross-sectional view taken along the line A2-A2 in FIG. It is a conceptual diagram for demonstrating the case where a speaker is installed in a space separated from a listening space by a shield. It is a figure for demonstrating the case where a speaker is installed in a vehicle.
  • FIG. 1 is a perspective view schematically showing the appearance of the speaker 10 according to the first embodiment.
  • FIG. 2 is a cross-sectional view of the speaker 10 according to the first embodiment.
  • X-axis X1 direction
  • Y1 direction the direction opposite to the X1 direction
  • Y2 direction the direction opposite to the Y1 direction
  • Z1 direction the direction opposite to the Z1 direction
  • Z2 direction the direction opposite to the Z1 direction
  • the Z-axis is an axis along the vibration direction of the diaphragm 21, which will be described later. Further, viewing from the Z1 direction or the Z2 direction is referred to as "planar view”.
  • the speaker 10 is, for example, an in-vehicle speaker arranged inside an instrument panel of a vehicle such as an automobile or a panel such as a head console.
  • the speaker 10 is driven by an audio signal input from an external device such as an amplifier (not shown) to emit sound based on the audio signal.
  • the voice signal is a signal indicating voice limited to a predetermined frequency band.
  • the predetermined frequency band is, for example, a band generally used for voice communication, and specifically, is in the range of 0.3 KHz or more and 3.4 KHz or less.
  • the use of the speaker 10 is not limited to in-vehicle use, and may be used for other purposes. Further, the speaker 10 is suitable when it is installed in a space separated from the listening space by a shield.
  • the speaker 10 is a speaker assembly having a sound emitting unit 20, a cabinet 30, and an acoustic member 40.
  • the sound emitting unit 20 has a diaphragm 21, a drive unit 22, and a frame 23, and is a structure in which these are unitized.
  • the diaphragm 21 is a vibrating body made of a sheet material.
  • the sheet material is obtained, for example, by curing or solidifying the fiber base material in a state of being impregnated with the resin material.
  • the resin material include acrylic resin, polyurethane, melamine resin, modified rubber resin, phenol resin and the like.
  • the fiber base material include carbon fiber, aramid fiber, glass fiber, ceramic fiber, silica fiber, metal fiber, potassium titanate fiber, zirconia fiber, polyacrylate fiber, polyphenylene sulfide fiber, vinylon fiber, rayon fiber, and nylon. Examples thereof include fibers, polyester fibers, acrylic fibers, polypropylene fibers, polyethylene fibers, cotton fibers, hemp fibers and cellulose fibers.
  • the diaphragm 21 has a sound emitting surface 21a that emits sound.
  • the diaphragm 21 is arranged so as to vibrate in the direction along the Z axis, and the sound emitting surface 21a is a surface of both sides of the diaphragm 21 facing the Z1 direction.
  • the diaphragm 21 of this embodiment is a cone type. Therefore, it can be said that the sound emitting surface 21a is the inner wall surface of the diaphragm 21.
  • the shape of the diaphragm 21 is not limited to the cone shape, and may be, for example, a dome shape or the like.
  • the drive unit 22 is a mechanism that drives the diaphragm 21 based on the input audio signal.
  • the drive unit 22 has, for example, a coil fixed to the diaphragm 21 and a permanent magnet that generates a magnetic field acting on the coil.
  • the coil vibrates the diaphragm 21 by the interaction of magnetic force with the permanent magnet when an electric audio signal is input. Due to this vibration, a sound based on the sound signal is emitted from the sound emitting surface 21a.
  • the drive unit 22 may drive the diaphragm 21 based on an audio signal, and is not limited to a configuration having a coil and a permanent magnet, and is arbitrary.
  • the frame 23 is a structure that supports the diaphragm 21 and the drive unit 22.
  • the frame 23 is made of, for example, iron or a metal material or a resin material.
  • the diaphragm 21 and the drive unit 22 are appropriately fixed to the frame 23 with screws, adhesives, or the like.
  • the shape of the frame 23 is not limited to the shape shown in FIG. 2, and is arbitrary as long as it can support the diaphragm 21 and the drive unit 22.
  • the cabinet 30 is a box body to which the sound emitting unit 20 and the acoustic member 40 are attached.
  • the cabinet 30 is made of, for example, a resin material or a metal material.
  • the cabinet 30 is roughly a hollow rectangular parallelepiped having a space S0.
  • the cabinet 30 includes side plates 31X1 and 31X2 arranged along the X axis, side plates 31Y1 and 31Y2 arranged along the Y axis, and top plates 31Z1 and bottom plates 31Z2 arranged along the Z axis.
  • Each of the side plates 31X1 and 31X2 is a flat plate-shaped member perpendicular to the X axis.
  • Each of the side plates 31Y1 and 31Y2 is a flat plate-shaped member perpendicular to the Y axis.
  • Each of the top plate 31Z1 and the bottom plate 31Z2 is a flat plate-shaped member perpendicular to the Z axis.
  • the sound emitting unit 20 and the acoustic member 40 are attached to the top plate 31Z1.
  • each of the sound emitting unit 20 and the acoustic member 40 is fixed to the top plate 31Z1 by fitting, screwing, adhesive, or the like.
  • the sound emitting unit 20 is arranged between the top plate 31Z1 and the bottom plate 31Z2. Therefore, the sound emitting unit 20 is arranged in the space S0 of the cabinet 30.
  • the top plate 31Z1 is provided with an opening 32 for exposing the sound emitting surface 21a of the diaphragm 21 to the external space.
  • the acoustic member 40 is a member that is arranged so as to form a space S1 with the sound emitting surface 21a of the diaphragm 21 and has an opening 41.
  • the acoustic member 40 of the present embodiment has a plate shape and is arranged along a plane perpendicular to the Z axis, as will be described in detail later.
  • the space S1 and the opening 41 constitute a Helmholtz resonator.
  • the Helmholtz resonator enhances the frequency components of the sound from the sound emitting surface 21a within a predetermined frequency band of the audio signal, and attenuates the components exceeding the predetermined frequency band.
  • FIG. 3 is a diagram conceptually showing a typical Helmholtz resonator 50.
  • the Helmholtz resonator 50 has a container 51 and a tube 52 connected to the container 51.
  • the air in the container 51 and the pipe 52 constitutes a vibration system in which the air in the pipe 52 is the mass and the air in the container 51 is a spring. Therefore, the Helmholtz resonator 50 increases the sound pressure at the resonance frequency of this vibration system. Further, the Helmholtz resonator 50 lowers the sound pressure in a band higher than a predetermined value from the resonance frequency of this vibration system.
  • the resonance frequency f 0 of the Helmholtz resonator 50 is expressed by the following equation (1). It is represented by.
  • the resonance frequency f 0 of the Helmholtz resonator 50 can be adjusted according to the volume V, the cross-sectional area s, and the length l. Specifically, the smaller the volume V or length l, or the larger the cross-sectional area s, the larger the resonance frequency f 0 .
  • the space S1 corresponds to the space inside the container 51 described above.
  • the opening 41 of the acoustic member 40 corresponds to the above-mentioned pipe 52. Therefore, the length of the opening 41 along the Z axis corresponds to the above-mentioned length l. Therefore, the desired resonance frequency f 0 can be adjusted according to the cross-sectional area or length of the opening 41. Further, the resonance frequency f 0 can be selected by preparing a plurality of acoustic members 40 having different cross-sectional areas or lengths of the openings 41 and exchanging the acoustic members 40 attached to the cabinet 30.
  • FIG. 4 is a graph showing the frequency characteristics of the sound from the speaker 10.
  • the characteristics of the speaker 10 having the acoustic member 40 are shown by a solid line, and the characteristics when the acoustic member 40 is omitted from the speaker 10 are shown by a broken line.
  • FIG. 4 shows a case where the frequency band of the audio signal is in the range of 0.3 KHz or more and 3.4 KHz or less.
  • the resonance frequency f 0 of the Helmholtz resonator described above is near the upper limit of the frequency band of the audio signal.
  • the components in the frequency band of the audio signal are enhanced and the components exceeding the frequency band of the audio signal are attenuated as compared with the case where the acoustic member 40 is not used.
  • the resonance frequency f 0 is a frequency exceeding the frequency band of the audio signal, but the frequency is not limited to this, and the resonance frequency f 0 may be a frequency within the frequency band of the audio signal. However, from the viewpoint that the S / N ratio can be easily and effectively increased , it is preferable that the resonance frequency f 0 is a frequency higher than the center frequency in the frequency band of the audio signal.
  • FIG. 5 of the acoustic member 40 is a plan view of the acoustic member 40 according to the first embodiment.
  • FIG. 6 is a cross-sectional view taken along the line A1-A1 in FIG.
  • the acoustic member 40 has a substantially circular outer shape in a plan view.
  • four protrusions 42 are provided on the outer circumference of the acoustic member 40. Therefore, by fitting the shape of the opening 32 of the cabinet 30 to the outer periphery of the acoustic member 40, it is possible to prevent the acoustic member 40 from being displaced with respect to the cabinet 30 in the circumferential direction.
  • the shape, position, number, and the like of the protrusions 42 are not limited to the example shown in FIG. 5, and are arbitrary. Further, the protrusion 42 may be provided as needed, or may be omitted.
  • the acoustic member 40 has a plate shape as described above, and has an opening 41 penetrating in the thickness direction.
  • the number of openings 41 included in the acoustic member 40 is one.
  • the opening 41 of the acoustic member 40 has a circular shape including the central PC of the sound emitting surface 21a in a plan view.
  • the plan view shape of the opening 41 is not limited to a circle, and may be, for example, a polygon such as a triangle, a quadrangle, a pentagon or a hexagon, or a slit shape, a star shape or an ellipse shape.
  • the thickness of the acoustic member 40 includes a first portion 43 having a constant thickness and a second portion 44 thicker than the first portion 43.
  • the first portion 43 is an annular portion along the outer circumference of the acoustic member 40.
  • the thickness of the first portion 43 is constant at the thickness t1.
  • a convex portion 45 extending along the circumferential direction of the acoustic member 40 is provided on the surface of the first portion 43 facing the Z2 direction.
  • the convex portion 45 comes into contact with the wall surface of the opening 32 of the cabinet 30. Therefore, the misalignment of the acoustic member 40 with respect to the cabinet 30 is prevented.
  • the convex portion 45 may be provided as needed or may be omitted.
  • the second part 44 is a part inside the first part 43 of the acoustic member 40.
  • the thickness of the second portion 44 changes from the thickness t1 to the thickness t2 from the outside to the inside in the radial direction of the acoustic member 40.
  • the thickness of the second portion 44 changes continuously from the outside to the inside in the radial direction of the acoustic member 40.
  • the thickness of the second portion 44 may change stepwise from the outside to the inside in the radial direction of the acoustic member 40.
  • the second portion 44 is provided with an opening 41. Therefore, the length l of the opening 41 is equal to the thickness t2 of the second portion 44.
  • the width of the opening 41 increases from the center of the opening 41 toward the Z1 direction and the Z2 direction. Therefore, the loss of sound in the opening 41 is reduced as compared with the case where the width of the opening 41 is constant.
  • the width of the opening 41 may be constant.
  • the speaker 10 has a diaphragm 21, a drive unit 22, and an acoustic member 40.
  • the diaphragm 21 has a sound emitting surface 21a that emits sound.
  • the drive unit 22 drives the diaphragm 21 based on an audio signal indicating a voice limited to a predetermined frequency band.
  • the acoustic member 40 has one opening 41, and is arranged so as to form a space S1 constituting the Helmholtz resonator together with the one opening 41 with the sound emitting surface 21a.
  • the Helmholtz resonator enhances the frequency components of the sound from the sound emitting surface 21a within the predetermined frequency band, and attenuates the components exceeding the predetermined frequency band.
  • the components within the predetermined frequency band of the audio signal are enhanced. Therefore, even in an environment where there is an obstacle in front of the speaker 10, it is possible to reduce the volume decrease in the predetermined frequency band. Moreover, among the frequency components of the sound from the sound emitting surface 21a, the components exceeding a predetermined frequency band of the audio signal are attenuated. Therefore, the sound generated by the harmonic distortion of the speaker 10 can be reduced. From the above, since the S / N ratio is improved, it is possible to make it easier to hear the sound from the speaker 10 even in an environment where there is an obstacle in front of the speaker 10.
  • the speaker 10 has a sound emitting unit 20, a cabinet 30, and a plate-shaped acoustic member 40.
  • the sound emitting unit 20 includes a cone-shaped diaphragm 21 having a sound emitting surface 21a for emitting sound.
  • the sound emitting unit 20 is attached to the cabinet 30 with the sound emitting surface 21a exposed to the external space.
  • the acoustic member 40 is attached to the cabinet 30 in a state where the space S1 constituting the Helmholtz resonator is arranged between the sound emitting surface 21a and the sound emitting surface 21a together with one opening 41.
  • the diaphragm 21 of the present embodiment is a cone type. Therefore, the acoustic member 40 can be configured by using a plate-shaped member or the like. Therefore, it is not necessary for the acoustic member 40 to have a complicated shape or to separately prepare a member such as a spacer for securing the required size of the space S1. Further, the size of the speaker 10 can be reduced.
  • the acoustic member 40 of this embodiment is a plate-shaped lid member. Therefore, as compared with the case where the shape of the acoustic member 40 is a complicated shape such as a box shape, the manufacturing and mounting of the acoustic member 40 can be facilitated.
  • the thickness of the acoustic member 40 increases toward the opening 41. Therefore, the neck length l of the Helmholtz resonator can be lengthened by utilizing the plate thickness of the acoustic member 40. As a result, the acoustic member 40 can be easily manufactured. Further, since the thickness of the outer peripheral portion of the acoustic member 40 used for attachment is reduced, the configuration relating to the attachment of the acoustic member 40 is simplified.
  • the opening 41 is one opening including the central PC of the diaphragm 21 when viewed from the direction in which the acoustic member 40 and the diaphragm 21 overlap (Z1 direction or Z2 direction). Therefore, it is easy to increase the cross-sectional area of the openings 41 as compared with the case where the acoustic member 40 is provided with a plurality of openings. Therefore, there is an advantage that the resonance frequency f 0 of the Helmholtz resonator can be easily increased.
  • FIG. 7 is a plan view of the acoustic member 40A in the second embodiment.
  • FIG. 8 is a cross-sectional view taken along the line A2-A2 in FIG.
  • the acoustic member 40A is the same as the acoustic member 40A of the first embodiment described above, except that it has a plurality of openings 41A instead of one opening 41 and the thickness is different.
  • the acoustic member 40A has a plurality of openings 41A.
  • the plurality of openings 41A form a Helmholtz resonator together with the space S1 between the acoustic member 40A and the sound emitting surface 21a described above.
  • the total cross-sectional area of the plurality of openings 41A corresponds to the above-mentioned cross-sectional area s.
  • each opening 41A is regularly arranged in a staggered pattern. Further, each opening 41A has a circular shape in a plan view.
  • the arrangement of the plurality of openings 41A may be another regular arrangement such as a matrix, or may be random. However, when the arrangement of the plurality of openings 41A is regular, the design of the acoustic member 40A is easier than when the arrangement of the plurality of openings 41A is random.
  • the plan view shape of each opening 41A is not limited to a circle, and may be, for example, a polygon such as a triangle, a quadrangle, a pentagon or a hexagon, or a slit shape, a star shape or an ellipse shape.
  • the number of openings 41A is not limited to the number shown in FIG. 7, and is arbitrary. Further, the sizes of the plurality of openings 41A may be different from each other.
  • recesses 46 and 47 are provided on the surface of the acoustic member 40A facing the Z2 direction. Therefore, the volume of the space S1 can be increased as compared with the case where the recesses 46 and 47 are omitted. Further, the length of each opening 41A along the Z axis can be reduced.
  • the width W1 of the recess 46 is larger than the width W2 of the recess 47.
  • the wall portion 45A surrounding the concave portion 46 prevents the acoustic member 40 from being displaced with respect to the cabinet 30 as in the case of the convex portion 45 described above.
  • each opening 41A can be sized so that a finger or the like cannot enter. Therefore, it is possible to reduce damage to the diaphragm 21 when the acoustic member 40A is installed.
  • FIG. 9 is a conceptual diagram for explaining a case where the speaker 10 is installed in the listening space S2 and the space S3 separated by the shield 200.
  • the listening space S2 is a space in which the user U exists.
  • Space S3 is a space in which the speaker 10 is installed.
  • the shield 200 is a structure that separates the listening space S2 and the space S3. In the example shown in FIG. 9, the shield 200 has a shape surrounding the space S3. Further, the shield 200 is provided with a plurality of holes 201.
  • the sound from the speaker 10 is transmitted from the space S3 to the listening space S2 through each hole 201.
  • the shield 200 it may not be possible to arrange the hole 201 in front of the speaker 10. Even in this case, since the sound pressure is adjusted by the Helmholtz resonator in the speaker 10 as described above, the user U can easily hear the sound from the speaker 10.
  • FIG. 10 is a diagram for explaining a case where the speaker 10 is installed in the vehicle 100.
  • FIG. 10 shows a case where the speaker 10 is installed inside the instrument panel 101 of the vehicle 100.
  • the vehicle 100 having the speaker 10 in this way, even if the speaker 10 is arranged inside the instrument panel 101, the sound from the speaker 10 can be easily heard. Therefore, since the degree of freedom in designing the instrument panel 101 is increased, it is possible to provide the vehicle 100 having excellent design.
  • the acoustic member 40 or 40A has a plate shape is exemplified, but the present invention is not limited to this example.
  • the acoustic member may be in the shape of a tray.
  • the acoustic member 40 or 40A is separate from the cabinet 30, but the present invention is not limited to this, and the acoustic member 40 or 40A may be integrated with the cabinet 30.
  • the speaker drives the vibrating plate based on a vibrating plate having a sound emitting surface for emitting sound and an audio signal indicating sound limited to a predetermined frequency band.
  • a driving unit and an acoustic member having at least one opening and arranged so as to form a space forming a Helmholtz resonator together with the at least one opening between the sound emitting surface and the sound emitting surface. Then, the Helmholtz resonator enhances the frequency component of the sound from the sound emitting surface within the predetermined frequency band and attenuates the component exceeding the predetermined frequency band.
  • the components within the predetermined frequency band of the audio signal are enhanced. Therefore, even in an environment where there is an obstacle in front of the speaker, it is possible to reduce the volume decrease in the predetermined frequency band. Moreover, among the frequency components of the sound from the sound emitting surface, the components exceeding a predetermined frequency band of the audio signal are attenuated. Therefore, it is possible to reduce the sound generated by the harmonic distortion of the speaker. From the above, since the S / N ratio is improved, it is possible to make it easier to hear the sound from the speaker even in an environment where there is an obstacle in front of the speaker.
  • the diaphragm is a cone type.
  • the acoustic member can be configured by using a member such as a plate. Therefore, it is not necessary for the acoustic member to have a complicated shape or to separately prepare a member such as a spacer for securing the required size of the space. In addition, the size of the speaker can be reduced.
  • the acoustic member is a plate-shaped lid member. According to the above aspects, the manufacturing and mounting of the acoustic member becomes easier than in the case where the shape of the acoustic member is a complicated shape such as a box shape.
  • the thickness of the acoustic member increases toward at least one opening.
  • the neck length of the Helmholtz resonator can be increased by utilizing the plate thickness of the acoustic member.
  • the manufacturing of the acoustic member becomes easy.
  • the thickness of the outer peripheral portion of the acoustic member used for attachment can be reduced, and as a result, the configuration related to the attachment of the acoustic member is simplified.
  • the at least one opening includes the center of the diaphragm when viewed from the direction in which the acoustic member and the diaphragm overlap. It is one opening. According to the above aspect, it is easy to increase the cross-sectional area of the openings as compared with the case where the number of openings is a plurality. Therefore, there is an advantage that the resonance frequency of the Helmholtz resonator can be easily increased.
  • the at least one opening is a plurality of openings.
  • the opening can be sized so that a finger or the like cannot enter. Therefore, damage to the diaphragm at the time of installation of the acoustic member can be reduced.
  • the speaker according to a preferred embodiment (seventh aspect) of the present invention includes a sound emitting unit including a cone-shaped diaphragm having a sound emitting surface for emitting sound, and the sound emitting surface in a state of being exposed to an external space. It has a cabinet to which the sound emitting unit is mounted and a plate-shaped acoustic member having at least one opening and being attached to the cabinet, the acoustic member having a Helmholtz resonator together with the at least one opening. It is arranged so as to form a space to be formed between the sound emitting surface and the sound emitting surface.
  • the Helmholtz resonator enhances the frequency component of the sound from the sound emitting surface within a predetermined frequency band of the audio signal, and attenuates the component exceeding the predetermined frequency band. be able to. Therefore, since the S / N ratio is improved as in the first aspect described above, it is possible to easily hear the sound from the speaker even in an environment where there is an obstacle in front of the speaker.
  • the resonance frequency of the Helmholtz resonator is in the range of 2 KHz or more and 5 KHz or less. According to the above aspect, since the S / N ratio is improved, the sound from the speaker becomes easier to hear.
  • the vehicle according to the preferred aspect (9th aspect) of the present invention has the speaker of any of the above-mentioned aspects. According to the above aspect, even if the speaker is arranged inside the panel such as the instrument panel or the head console, the sound from the speaker can be easily heard. Therefore, it is possible to provide a vehicle having excellent design.
  • the speaker is installed in a space separated from the listening space by a shield. According to the above aspect, since the sound from the speaker is attenuated by the shield and then heard in the listening space, the effect obtained by applying the present invention is remarkable.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Mechanical Engineering (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
  • Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)

Abstract

A speaker including: a vibrating plate having a sound-emitting surface that emits sound; a drive unit that drives the vibrating plate on the basis of an audio signal indicating audio limited to a prescribed frequency band; and an acoustic member that has at least one opening part and is positioned so as to form, together with the sound-emitting surface, a space constituting a Helmholtz resonator together with said at least one opening part. The Helmholtz resonator enhances components that, among the frequency components of the sound from the sound-emitting surface, are within said prescribed frequency band, and attenuates components exceeding said prescribed frequency band.

Description

スピーカーおよび車両Speakers and vehicles
　本発明は、スピーカーおよび車両に関する。 The present invention relates to a speaker and a vehicle.
　ヘルムホルツ共鳴を利用するスピーカーが知られている。例えば、特許文献１には、ハウジングに収納された振動板の振動により音を発する発音ユニットが開示される。当該ハウジングは、当該振動板の前方に設けられるケース本体部を有する。当該ケース本体部と当該振動板との間には、空間が形成されており、当該ケース本体部には、複数の開口部が設けられる。当該空間および当該開口部によってヘルムホルツ共鳴器が構成される。特許文献１に記載のユニットでは、振動板から発せられた音における基本周波数の音圧が当該ヘルムホルツ共鳴器によって高められる。 Speakers that use Helmholtz resonance are known. For example, Patent Document 1 discloses a sounding unit that emits sound by vibrating a diaphragm housed in a housing. The housing has a case body provided in front of the diaphragm. A space is formed between the case main body and the diaphragm, and the case main body is provided with a plurality of openings. The space and the opening constitute a Helmholtz resonator. In the unit described in Patent Document 1, the sound pressure of the fundamental frequency in the sound emitted from the diaphragm is increased by the Helmholtz resonator.
特開２０１２－７０１８７号公報Japanese Unexamined Patent Publication No. 2012-70187
　例えば、車載用等のスピーカーは、インストルメントパネルまたはヘッドコンソール等のパネルの内側に配置される。ここで、意匠的な観点等からスピーカーがパネルにより覆われる場合がある。この場合、当該パネルがスピーカーからの音の伝播を妨げる障害物となり、スピーカーからの高域の音が減衰してしまう。特許文献１に記載のユニットでは、当該高域の音を好適に高めることができない。このため、特許文献１に記載のユニットでは、車載用等として用いた場合、スピーカーからの音声が聞き取りづらくなるという課題がある。 For example, in-vehicle speakers are arranged inside a panel such as an instrument panel or a head console. Here, the speaker may be covered with a panel from a design point of view or the like. In this case, the panel becomes an obstacle that hinders the propagation of the sound from the speaker, and the high-frequency sound from the speaker is attenuated. The unit described in Patent Document 1 cannot suitably enhance the high-frequency sound. Therefore, the unit described in Patent Document 1 has a problem that it becomes difficult to hear the sound from the speaker when it is used for in-vehicle use or the like.
　以上の事情を考慮して、本発明は、スピーカーの正面に対向する位置に障害物がある環境下でも、スピーカーからの音声を聞き取りやすくすることを目的とする。 In consideration of the above circumstances, an object of the present invention is to make it easier to hear the sound from the speaker even in an environment where there is an obstacle at a position facing the front of the speaker.
　以上の課題を解決するために、本発明の好適な態様に係るスピーカーは、放音する放音面を有する振動板と、所定の周波数帯域に制限された音声を示す音声信号に基づいて、前記振動板を駆動する駆動部と、少なくとも１つの開口部を有し、前記少なくとも１つの開口部とともにヘルムホルツ共鳴器を構成する空間を前記放音面との間に形成するように配置される音響部材と、を有し、前記ヘルムホルツ共鳴器は、前記放音面からの音の周波数成分のうち、前記所定の周波数帯域内の成分を増強させるとともに、前記所定の周波数帯域を超える成分を減衰させる。 In order to solve the above problems, the speaker according to a preferred embodiment of the present invention is based on a vibrating plate having a sound emitting surface for emitting sound and an audio signal indicating sound limited to a predetermined frequency band. An acoustic member having a driving unit for driving a vibrating plate and at least one opening, and arranged so as to form a space forming a Helmholtz resonator together with the at least one opening between the sound emitting surface and the sound emitting surface. The Helmholtz resonator enhances the components within the predetermined frequency band among the frequency components of the sound from the sound emitting surface, and attenuates the components exceeding the predetermined frequency band.
　本発明の他の好適な態様に係るスピーカーは、放音する放音面を有するコーン型の振動板を含む放音ユニットと、前記放音面を外部空間に露出させた状態で前記放音ユニットが取り付けられるキャビネットと、少なくとも１つの開口部を有し、前記キャビネットに取り付けられる板状の音響部材と、を有し、前記音響部材は、前記少なくとも１つの開口部とともにヘルムホルツ共鳴器を構成する空間を前記放音面との間に形成するように配置される。 The speaker according to another preferred embodiment of the present invention includes a sound emitting unit including a cone-shaped diaphragm having a sound emitting surface for emitting sound, and the sound emitting unit in a state where the sound emitting surface is exposed to an external space. Has a cabinet to which the is mounted and a plate-shaped acoustic member that has at least one opening and is attached to the cabinet, the acoustic member, together with the at least one opening, a space that constitutes a Helmholtz resonator. Is arranged so as to form between the sound emitting surface and the sound emitting surface.
　本発明の好適な態様に係る車両は、前述のいずれかの態様に係るスピーカーを有する。 The vehicle according to a preferred embodiment of the present invention has a speaker according to any of the above-mentioned aspects.
第１実施形態に係るスピーカーの外観を概略的に示す斜視図である。It is a perspective view which shows schematic appearance of the speaker which concerns on 1st Embodiment. 第１実施形態に係るスピーカーの断面図である。It is sectional drawing of the speaker which concerns on 1st Embodiment. 典型的なヘルムホルツ共鳴器を概念的に示す図である。It is a figure which conceptually shows a typical Helmholtz resonator. スピーカーからの音の周波数特性を示すグラフである。It is a graph which shows the frequency characteristic of the sound from a speaker. 第１実施形態における音響部材の平面図である。It is a top view of the acoustic member in 1st Embodiment. 図５中のＡ１－Ａ１線断面図である。FIG. 5 is a cross-sectional view taken along the line A1-A1 in FIG. 第２実施形態における音響部材の平面図である。It is a top view of the acoustic member in 2nd Embodiment. 図７中のＡ２－Ａ２線断面図である。FIG. 7 is a cross-sectional view taken along the line A2-A2 in FIG. 聴取空間と遮蔽物により隔てられる空間にスピーカーが設置される場合を説明するための概念図である。It is a conceptual diagram for demonstrating the case where a speaker is installed in a space separated from a listening space by a shield. スピーカーが車両に設置される場合を説明するための図である。It is a figure for demonstrating the case where a speaker is installed in a vehicle.
　１．第１実施形態
　以下、本発明の第１実施形態について図面を参照して説明する。なお、図面において各部の寸法および縮尺は実際のものと適宜に異ならせてある。また、以下に記載する実施形態は、本発明の好適な具体例である。このため、本実施形態には、技術的に好ましい種々の限定が付されている。しかし、本発明の範囲は、以下の説明において特に本発明を限定する旨の記載がない限り、これらの形態に限られるものではない。 1. 1. First Embodiment Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. In the drawings, the dimensions and scale of each part are appropriately different from the actual ones. Moreover, the embodiment described below is a preferable specific example of the present invention. For this reason, the present embodiment is provided with various technically preferable limitations. However, the scope of the present invention is not limited to these forms unless it is stated in the following description that the present invention is particularly limited.
　１－１．スピーカーの概略
　図１は、第１実施形態に係るスピーカー１０の外観を概略的に示す斜視図である。図２は、第１実施形態に係るスピーカー１０の断面図である。 1-1. Schematic FIG. 1 is a perspective view schematically showing the appearance of the speaker 10 according to the first embodiment. FIG. 2 is a cross-sectional view of the speaker 10 according to the first embodiment.
　以下では、説明の便宜上、互いに直交する「Ｘ軸」、「Ｙ軸」および「Ｚ軸」を適宜に用いて説明する。また、Ｘ軸に沿う一方向を「Ｘ１方向」といい、Ｘ１方向とは反対の方向を「Ｘ２方向」という。同様に、Ｙ軸に沿う一方向を「Ｙ１方向」といい、Ｙ１方向とは反対の方向を「Ｙ２方向」という。Ｚ軸に沿う一方向を「Ｚ１方向」といい、Ｚ１方向とは反対の方向を「Ｚ２方向」という。ここで、Ｚ軸は、後述する振動板２１の振動方向に沿う軸である。また、Ｚ１方向またはＺ２方向からみることを「平面視」という。 In the following, for convenience of explanation, the "X-axis", "Y-axis", and "Z-axis" that are orthogonal to each other will be described as appropriate. Further, one direction along the X axis is referred to as "X1 direction", and the direction opposite to the X1 direction is referred to as "X2 direction". Similarly, one direction along the Y axis is referred to as "Y1 direction", and the direction opposite to the Y1 direction is referred to as "Y2 direction". One direction along the Z axis is referred to as "Z1 direction", and the direction opposite to the Z1 direction is referred to as "Z2 direction". Here, the Z-axis is an axis along the vibration direction of the diaphragm 21, which will be described later. Further, viewing from the Z1 direction or the Z2 direction is referred to as "planar view".
　スピーカー１０は、例えば、自動車等の車両のインストルメントパネルまたはヘッドコンソール等のパネルの内側に配置される車載用のスピーカーである。スピーカー１０は、図示しないアンプ等の外部装置から入力される音声信号により駆動されることで、当該音声信号に基づく音声を放音する。当該音声信号は、所定の周波数帯域に制限された音声を示す信号である。当該所定の周波数帯域は、例えば、一般に音声通信に用いられる帯域であり、具体的には、０．３ＫＨｚ以上３．４ＫＨｚ以下の範囲である。 The speaker 10 is, for example, an in-vehicle speaker arranged inside an instrument panel of a vehicle such as an automobile or a panel such as a head console. The speaker 10 is driven by an audio signal input from an external device such as an amplifier (not shown) to emit sound based on the audio signal. The voice signal is a signal indicating voice limited to a predetermined frequency band. The predetermined frequency band is, for example, a band generally used for voice communication, and specifically, is in the range of 0.3 KHz or more and 3.4 KHz or less.
　なお、スピーカー１０の用途は、車載用に限定されず、他の用途でもよい。また、スピーカー１０は、聴取空間と遮蔽物により隔てられる空間に設置される場合に好適である。 The use of the speaker 10 is not limited to in-vehicle use, and may be used for other purposes. Further, the speaker 10 is suitable when it is installed in a space separated from the listening space by a shield.
　図１および図２に示すように、スピーカー１０は、放音ユニット２０とキャビネット３０と音響部材４０とを有するスピーカーアセンブリである。 As shown in FIGS. 1 and 2, the speaker 10 is a speaker assembly having a sound emitting unit 20, a cabinet 30, and an acoustic member 40.
　図２に示すように、放音ユニット２０は、振動板２１と駆動部２２とフレーム２３とを有し、これらをユニット化した構造体である。 As shown in FIG. 2, the sound emitting unit 20 has a diaphragm 21, a drive unit 22, and a frame 23, and is a structure in which these are unitized.
　振動板２１は、シート材で構成される振動体である。当該シート材は、例えば、樹脂材料を繊維基材に含浸させた状態で硬化または固化することで得られる。当該樹脂材料としては、例えば、アクリル樹脂、ポリウレタン、メラミン樹脂、変性ゴム樹脂およびフェノール樹脂等が挙げられる。当該繊維基材としては、例えば、炭素繊維、アラミド繊維、ガラス繊維、セラミック繊維、シリカ繊維、金属繊維、チタン酸カリウム繊維、ジルコニア繊維、ポリアクリレート繊維、ポリフェニレンサルファイド繊維、ビニロン繊維、レーヨン繊維、ナイロン繊維、ポリエステル繊維、アクリル繊維、ポリプロピレン繊維、ポリエチレン繊維、綿繊維、麻繊維およびセルロース繊維等が挙げられる。 The diaphragm 21 is a vibrating body made of a sheet material. The sheet material is obtained, for example, by curing or solidifying the fiber base material in a state of being impregnated with the resin material. Examples of the resin material include acrylic resin, polyurethane, melamine resin, modified rubber resin, phenol resin and the like. Examples of the fiber base material include carbon fiber, aramid fiber, glass fiber, ceramic fiber, silica fiber, metal fiber, potassium titanate fiber, zirconia fiber, polyacrylate fiber, polyphenylene sulfide fiber, vinylon fiber, rayon fiber, and nylon. Examples thereof include fibers, polyester fibers, acrylic fibers, polypropylene fibers, polyethylene fibers, cotton fibers, hemp fibers and cellulose fibers.
　振動板２１は、放音する放音面２１ａを有する。振動板２１は、Ｚ軸に沿う方向に振動するように配置されており、放音面２１ａは、振動板２１の両面のうちのＺ１方向を向く面である。本実施形態の振動板２１は、コーン型である。このため、放音面２１ａは、振動板２１の内壁面であるともいえる。なお、振動板２１の形状は、コーン型に限定されず、例えば、ドーム型等でもよい。 The diaphragm 21 has a sound emitting surface 21a that emits sound. The diaphragm 21 is arranged so as to vibrate in the direction along the Z axis, and the sound emitting surface 21a is a surface of both sides of the diaphragm 21 facing the Z1 direction. The diaphragm 21 of this embodiment is a cone type. Therefore, it can be said that the sound emitting surface 21a is the inner wall surface of the diaphragm 21. The shape of the diaphragm 21 is not limited to the cone shape, and may be, for example, a dome shape or the like.
　駆動部２２は、入力される音声信号に基づいて振動板２１を駆動する機構である。駆動部２２は、例えば、振動板２１に固定されるコイルと、当該コイルに作用する磁界を発生させる永久磁石と、を有する。当該コイルは、電気的な音声信号が入力されることで、当該永久磁石との間における磁力の相互作用により振動板２１を振動させる。この振動により、放音面２１ａから当該音声信号に基づく音声が放音される。なお、駆動部２２は、音声信号に基づいて振動板２１を駆動することができればよく、コイルおよび永久磁石を有する構成に限定されず、任意である。 The drive unit 22 is a mechanism that drives the diaphragm 21 based on the input audio signal. The drive unit 22 has, for example, a coil fixed to the diaphragm 21 and a permanent magnet that generates a magnetic field acting on the coil. The coil vibrates the diaphragm 21 by the interaction of magnetic force with the permanent magnet when an electric audio signal is input. Due to this vibration, a sound based on the sound signal is emitted from the sound emitting surface 21a. The drive unit 22 may drive the diaphragm 21 based on an audio signal, and is not limited to a configuration having a coil and a permanent magnet, and is arbitrary.
　フレーム２３は、振動板２１および駆動部２２を支持する構造体である。フレーム２３は、例えば、鉄または金属材料または樹脂材料で構成される。フレーム２３には、振動板２１および駆動部２２がネジ止めまたは接着剤等により適宜に固定される。なお、フレーム２３の形状は、振動板２１および駆動部２２を支持することができればよく、図２に示す形状に限定されず、任意である。 The frame 23 is a structure that supports the diaphragm 21 and the drive unit 22. The frame 23 is made of, for example, iron or a metal material or a resin material. The diaphragm 21 and the drive unit 22 are appropriately fixed to the frame 23 with screws, adhesives, or the like. The shape of the frame 23 is not limited to the shape shown in FIG. 2, and is arbitrary as long as it can support the diaphragm 21 and the drive unit 22.
　キャビネット３０は、放音ユニット２０および音響部材４０が取り付けられる箱体である。キャビネット３０は、例えば、樹脂材料または金属材料で構成される。 The cabinet 30 is a box body to which the sound emitting unit 20 and the acoustic member 40 are attached. The cabinet 30 is made of, for example, a resin material or a metal material.
　キャビネット３０は、概略的に、空間Ｓ０を有する中空の直方体である。具体的には、キャビネット３０は、Ｘ軸に沿う方向に並ぶ側板３１Ｘ１および３１Ｘ２と、Ｙ軸に沿う方向に並ぶ側板３１Ｙ１および３１Ｙ２と、Ｚ軸に沿う方向に並ぶ天板３１Ｚ１および底板３１Ｚ２と、を有する。側板３１Ｘ１および３１Ｘ２のそれぞれは、Ｘ軸に垂直な平板状の部材である。側板３１Ｙ１および３１Ｙ２のそれぞれは、Ｙ軸に垂直な平板状の部材である。天板３１Ｚ１および底板３１Ｚ２のそれぞれは、Ｚ軸に垂直な平板状の部材である。 The cabinet 30 is roughly a hollow rectangular parallelepiped having a space S0. Specifically, the cabinet 30 includes side plates 31X1 and 31X2 arranged along the X axis, side plates 31Y1 and 31Y2 arranged along the Y axis, and top plates 31Z1 and bottom plates 31Z2 arranged along the Z axis. Has. Each of the side plates 31X1 and 31X2 is a flat plate-shaped member perpendicular to the X axis. Each of the side plates 31Y1 and 31Y2 is a flat plate-shaped member perpendicular to the Y axis. Each of the top plate 31Z1 and the bottom plate 31Z2 is a flat plate-shaped member perpendicular to the Z axis.
　これらの板のうち、天板３１Ｚ１には、放音ユニット２０および音響部材４０が取り付けられる。ここで、放音ユニット２０および音響部材４０のそれぞれは、天板３１Ｚ１に対して嵌合、ネジ止めまたは接着剤等により固定される。放音ユニット２０は、天板３１Ｚ１と底板３１Ｚ２との間に配置される。したがって、放音ユニット２０は、キャビネット３０の空間Ｓ０内に配置される。また、天板３１Ｚ１には、振動板２１の放音面２１ａを外部空間に露出させるための開口部３２が設けられる。 Of these plates, the sound emitting unit 20 and the acoustic member 40 are attached to the top plate 31Z1. Here, each of the sound emitting unit 20 and the acoustic member 40 is fixed to the top plate 31Z1 by fitting, screwing, adhesive, or the like. The sound emitting unit 20 is arranged between the top plate 31Z1 and the bottom plate 31Z2. Therefore, the sound emitting unit 20 is arranged in the space S0 of the cabinet 30. Further, the top plate 31Z1 is provided with an opening 32 for exposing the sound emitting surface 21a of the diaphragm 21 to the external space.
　音響部材４０は、前述の振動板２１の放音面２１ａとの間に空間Ｓ１を形成するように配置され、開口部４１を有する部材である。本実施形態の音響部材４０は、後に詳述するように板状をなし、Ｚ軸に垂直な平面に沿って配置される。 The acoustic member 40 is a member that is arranged so as to form a space S1 with the sound emitting surface 21a of the diaphragm 21 and has an opening 41. The acoustic member 40 of the present embodiment has a plate shape and is arranged along a plane perpendicular to the Z axis, as will be described in detail later.
　空間Ｓ１および開口部４１は、ヘルムホルツ共鳴器を構成する。当該ヘルムホルツ共鳴器は、放音面２１ａからの音の周波数成分のうち、音声信号の所定の周波数帯域内の成分を増強させるとともに、当該所定の周波数帯域を超える成分を減衰させる。 The space S1 and the opening 41 constitute a Helmholtz resonator. The Helmholtz resonator enhances the frequency components of the sound from the sound emitting surface 21a within a predetermined frequency band of the audio signal, and attenuates the components exceeding the predetermined frequency band.
　このような音成分の増強により、スピーカー１０の正面に対向する位置に障害物がある環境下でも、当該所定の周波数帯域内における音量低下を低減する効果が得られる。また、このような音成分の減衰により、スピーカー１０の高調波歪みにより発生する音を低減する効果が得られる。これらの効果により、Ｓ／Ｎ比が改善されるので、スピーカー１０の正面に障害物がある環境下でも、スピーカー１０からの音声を聞き取りやすくすることができる。 By such enhancement of the sound component, it is possible to obtain the effect of reducing the volume decrease in the predetermined frequency band even in an environment where there is an obstacle at a position facing the front of the speaker 10. Further, such attenuation of the sound component has the effect of reducing the sound generated by the harmonic distortion of the speaker 10. Since the S / N ratio is improved by these effects, it is possible to make it easier to hear the sound from the speaker 10 even in an environment where there is an obstacle in front of the speaker 10.
　１－２．ヘルムホルツ共鳴器の作用
　図３は、典型的なヘルムホルツ共鳴器５０を概念的に示す図である。ヘルムホルツ共鳴器５０は、容器５１と、容器５１に接続される管５２と、を有する。ヘルムホルツ共鳴器５０では、容器５１内および管５２内の空気は、管５２内の空気を質量とし、容器５１内の空気をバネとする振動系を構成する。したがって、ヘルムホルツ共鳴器５０は、この振動系の共鳴周波数の音圧を高める。また、ヘルムホルツ共鳴器５０は、この振動系の共鳴周波数から所定以上高い帯域の音圧を低める。 1-2. Action of Helmholtz Resonator FIG. 3 is a diagram conceptually showing a typical Helmholtz resonator 50. The Helmholtz resonator 50 has a container 51 and a tube 52 connected to the container 51. In the Helmholtz resonator 50, the air in the container 51 and the pipe 52 constitutes a vibration system in which the air in the pipe 52 is the mass and the air in the container 51 is a spring. Therefore, the Helmholtz resonator 50 increases the sound pressure at the resonance frequency of this vibration system. Further, the Helmholtz resonator 50 lowers the sound pressure in a band higher than a predetermined value from the resonance frequency of this vibration system.
　ここで、容器５１内の体積をＶとし、管５２の長さをｌとし、管５２内の横断面積をｓとするとき、ヘルムホルツ共鳴器５０の共鳴周波数ｆ０は、以下の式（１）で表される。
Figure JPOXMLDOC01-appb-M000001
 Here, when the volume inside the container 51 is V, the length of the tube 52 is l, and the cross-sectional area inside the tube 52 is s, the resonance frequency f 0 of the Helmholtz resonator 50 is expressed by the following equation (1). It is represented by.
Figure JPOXMLDOC01-appb-M000001
　この式（１）において、ｃは、空気中の音速である。また、δは、開口端補正値であり、管５２内の横断面形状が円形である場合、管５２内の直径をｄとするとき、δ≒０．８×ｄで表される。前述の式（１）から理解される通り、体積Ｖ、断面積ｓおよび長さｌに応じて、ヘルムホルツ共鳴器５０の共鳴周波数ｆ０を調整することができる。具体的には、体積Ｖまたは長さｌが小さくなるほど、または、断面積ｓが大きくなるほど、共鳴周波数ｆ０が大きくなる。 In this equation (1), c is the speed of sound in the air. Further, δ is an end correction value, and when the cross-sectional shape in the pipe 52 is circular, it is represented by δ≈0.8 × d, where d is the diameter in the pipe 52. As understood from the above equation (1), the resonance frequency f 0 of the Helmholtz resonator 50 can be adjusted according to the volume V, the cross-sectional area s, and the length l. Specifically, the smaller the volume V or length l, or the larger the cross-sectional area s, the larger the resonance frequency f 0 .
　前述の構成のスピーカー１０において、空間Ｓ１は、前述の容器５１内の空間に相当する。また、音響部材４０の開口部４１が前述の管５２に相当する。したがって、Ｚ軸に沿う開口部４１の長さが前述の長さｌに相当する。このため、開口部４１の断面積または長さに応じて、所望の共鳴周波数ｆ０を調整することができる。また、開口部４１の断面積または長さの異なる複数の音響部材４０を用意しておき、キャビネット３０に取り付ける音響部材４０を交換することで、共鳴周波数ｆ０の選択が可能である。 In the speaker 10 having the above-described configuration, the space S1 corresponds to the space inside the container 51 described above. Further, the opening 41 of the acoustic member 40 corresponds to the above-mentioned pipe 52. Therefore, the length of the opening 41 along the Z axis corresponds to the above-mentioned length l. Therefore, the desired resonance frequency f 0 can be adjusted according to the cross-sectional area or length of the opening 41. Further, the resonance frequency f 0 can be selected by preparing a plurality of acoustic members 40 having different cross-sectional areas or lengths of the openings 41 and exchanging the acoustic members 40 attached to the cabinet 30.
　図４は、スピーカー１０からの音の周波数特性を示すグラフである。図４では、音響部材４０を有するスピーカー１０の特性が実線で示され、スピーカー１０から音響部材４０を省略した場合の特性が破線で示される。また、図４では、音声信号の周波数帯域が０．３ＫＨｚ以上３．４ＫＨｚ以下の範囲である場合が図示される。 FIG. 4 is a graph showing the frequency characteristics of the sound from the speaker 10. In FIG. 4, the characteristics of the speaker 10 having the acoustic member 40 are shown by a solid line, and the characteristics when the acoustic member 40 is omitted from the speaker 10 are shown by a broken line. Further, FIG. 4 shows a case where the frequency band of the audio signal is in the range of 0.3 KHz or more and 3.4 KHz or less.
　図４に示す例では、前述のヘルムホルツ共鳴器の共鳴周波数ｆ０が音声信号の周波数帯域の上限値付近である。この結果、音響部材４０を用いる場合、音響部材４０を用いない場合に比べて、音声信号の周波数帯域内の成分が増強されるとともに、音声信号の周波数帯域を超える成分が減衰される。 In the example shown in FIG. 4, the resonance frequency f 0 of the Helmholtz resonator described above is near the upper limit of the frequency band of the audio signal. As a result, when the acoustic member 40 is used, the components in the frequency band of the audio signal are enhanced and the components exceeding the frequency band of the audio signal are attenuated as compared with the case where the acoustic member 40 is not used.
　図４に示す例では、共鳴周波数ｆ０が音声信号の周波数帯域を超える周波数であるが、これに限定されず、共鳴周波数ｆ０が音声信号の周波数帯域内の周波数であってもよい。ただし、Ｓ／Ｎ比を容易かつ効果的に高められるという観点から、共鳴周波数ｆ０が音声信号の周波数帯域における中心周波数よりも高域の周波数であることが好ましい。 In the example shown in FIG. 4, the resonance frequency f 0 is a frequency exceeding the frequency band of the audio signal, but the frequency is not limited to this, and the resonance frequency f 0 may be a frequency within the frequency band of the audio signal. However, from the viewpoint that the S / N ratio can be easily and effectively increased , it is preferable that the resonance frequency f 0 is a frequency higher than the center frequency in the frequency band of the audio signal.
　具体的には、開口部４１および空間Ｓ１で構成されるヘルムホルツ共鳴器の共鳴周波数ｆ０は、前述のように、当該所定の周波数帯域内の成分を増強させるとともに、当該所定の周波数帯域を超える成分を減衰させることができればよいが、Ｓ／Ｎ比をより改善する観点から、例えば、好ましくは、１ＫＨｚ以上５ＫＨｚ以下の範囲内にあり、より好ましくは、２ＫＨｚ以上５ＫＨｚ以下の範囲内にある。 Specifically, the resonance frequency f 0 of the Helmholtz resonator constituted by the opening 41 and the space S1, as described above, along with enhancing the components within the predetermined frequency band, exceeds the predetermined frequency band It suffices if the components can be attenuated, but from the viewpoint of further improving the S / N ratio, for example, it is preferably in the range of 1 KHz or more and 5 KHz or less, and more preferably in the range of 2 KHz or more and 5 KHz or less.
　１－３．音響部材４０の詳細
　図５は、第１実施形態における音響部材４０の平面図である。図６は、図５中のＡ１－Ａ１線断面図である。図５に示すように、音響部材４０は、平面視で略円形の外形をなす。図５に示す例では、音響部材４０の外周には、４つの突起４２が設けられる。このため、前述のキャビネット３０の開口部３２の形状を音響部材４０の外周に嵌め合う形状とすることで、キャビネット３０に対する音響部材４０の周方向での位置ずれを防止することができる。なお、突起４２の形状、位置または数等は、図５に示す例に限定されず、任意である。また、突起４２は、必要に応じて設ければよく、省略してもよい。 1-3. Detailed FIG. 5 of the acoustic member 40 is a plan view of the acoustic member 40 according to the first embodiment. FIG. 6 is a cross-sectional view taken along the line A1-A1 in FIG. As shown in FIG. 5, the acoustic member 40 has a substantially circular outer shape in a plan view. In the example shown in FIG. 5, four protrusions 42 are provided on the outer circumference of the acoustic member 40. Therefore, by fitting the shape of the opening 32 of the cabinet 30 to the outer periphery of the acoustic member 40, it is possible to prevent the acoustic member 40 from being displaced with respect to the cabinet 30 in the circumferential direction. The shape, position, number, and the like of the protrusions 42 are not limited to the example shown in FIG. 5, and are arbitrary. Further, the protrusion 42 may be provided as needed, or may be omitted.
　音響部材４０は、前述のように板状をなしており、厚さ方向に貫通する開口部４１を有する。本実施形態では、音響部材４０が有する開口部４１の数は、１つである。図５に示す例では、音響部材４０の開口部４１は、平面視で、前述の放音面２１ａの中心ＰＣを包含する円形をなす。なお、開口部４１の平面視形状は、円形に限定されず、例えば、三角形、四角形、五角形または六角形等の多角形でもよいし、スリット状、星形または楕円形等でもよい。 The acoustic member 40 has a plate shape as described above, and has an opening 41 penetrating in the thickness direction. In the present embodiment, the number of openings 41 included in the acoustic member 40 is one. In the example shown in FIG. 5, the opening 41 of the acoustic member 40 has a circular shape including the central PC of the sound emitting surface 21a in a plan view. The plan view shape of the opening 41 is not limited to a circle, and may be, for example, a polygon such as a triangle, a quadrangle, a pentagon or a hexagon, or a slit shape, a star shape or an ellipse shape.
　図６に示すように、音響部材４０の厚さは、一定厚さの第１部分４３と、第１部分４３よりも厚い第２部分４４と、を有する。 As shown in FIG. 6, the thickness of the acoustic member 40 includes a first portion 43 having a constant thickness and a second portion 44 thicker than the first portion 43.
　第１部分４３は、音響部材４０における外周に沿う環状の部分である。第１部分４３の厚さは、厚さｔ１で一定である。図６に示す例では、第１部分４３におけるＺ２方向を向く面には、音響部材４０の周方向に沿って延びる凸部４５が設けられる。凸部４５は、キャビネット３０の開口部３２の壁面に接触する。このため、キャビネット３０に対する音響部材４０の位置ずれが防止される。なお、凸部４５は、必要に応じて設ければよく、省略してもよい。 The first portion 43 is an annular portion along the outer circumference of the acoustic member 40. The thickness of the first portion 43 is constant at the thickness t1. In the example shown in FIG. 6, a convex portion 45 extending along the circumferential direction of the acoustic member 40 is provided on the surface of the first portion 43 facing the Z2 direction. The convex portion 45 comes into contact with the wall surface of the opening 32 of the cabinet 30. Therefore, the misalignment of the acoustic member 40 with respect to the cabinet 30 is prevented. The convex portion 45 may be provided as needed or may be omitted.
　第２部分４４は、音響部材４０における第１部分４３よりも内側の部分である。第２部分４４の厚さは、音響部材４０の径方向での外側から内側に向かうに従い、厚さｔ１から厚さｔ２に変化する。図６に示す例では、第２部分４４の厚さは、音響部材４０の径方向での外側から内側に向かうに従い連続的に変化する。なお、第２部分４４の厚さは、音響部材４０の径方向での外側から内側に向かうに従い段階的に変化してもよい。 The second part 44 is a part inside the first part 43 of the acoustic member 40. The thickness of the second portion 44 changes from the thickness t1 to the thickness t2 from the outside to the inside in the radial direction of the acoustic member 40. In the example shown in FIG. 6, the thickness of the second portion 44 changes continuously from the outside to the inside in the radial direction of the acoustic member 40. The thickness of the second portion 44 may change stepwise from the outside to the inside in the radial direction of the acoustic member 40.
　第２部分４４には、開口部４１が設けられる。このため、開口部４１の長さｌは、第２部分４４の厚さｔ２に等しい。図６に示す例では、開口部４１の幅は、開口部４１の中心からＺ１方向およびＺ２方向に向かうに従い拡がる。このため、開口部４１の幅が一定である場合に比べて、開口部４１での音の損失が低減される。なお。開口部４１の幅が一定でもよい。 The second portion 44 is provided with an opening 41. Therefore, the length l of the opening 41 is equal to the thickness t2 of the second portion 44. In the example shown in FIG. 6, the width of the opening 41 increases from the center of the opening 41 toward the Z1 direction and the Z2 direction. Therefore, the loss of sound in the opening 41 is reduced as compared with the case where the width of the opening 41 is constant. In addition. The width of the opening 41 may be constant.
　以上のように、スピーカー１０は、振動板２１と駆動部２２と音響部材４０とを有する。振動板２１は、放音する放音面２１ａを有する。駆動部２２は、所定の周波数帯域に制限された音声を示す音声信号に基づいて、振動板２１を駆動する。音響部材４０は、１つの開口部４１を有し、当該１つの開口部４１とともにヘルムホルツ共鳴器を構成する空間Ｓ１を放音面２１ａとの間に形成するように配置される。当該ヘルムホルツ共鳴器は、放音面２１ａからの音の周波数成分のうち、当該所定の周波数帯域内の成分を増強させるとともに、当該所定の周波数帯域を超える成分を減衰させる。 As described above, the speaker 10 has a diaphragm 21, a drive unit 22, and an acoustic member 40. The diaphragm 21 has a sound emitting surface 21a that emits sound. The drive unit 22 drives the diaphragm 21 based on an audio signal indicating a voice limited to a predetermined frequency band. The acoustic member 40 has one opening 41, and is arranged so as to form a space S1 constituting the Helmholtz resonator together with the one opening 41 with the sound emitting surface 21a. The Helmholtz resonator enhances the frequency components of the sound from the sound emitting surface 21a within the predetermined frequency band, and attenuates the components exceeding the predetermined frequency band.
　以上のスピーカー１０では、放音面２１ａからの音の周波数成分のうち、音声信号の所定の周波数帯域内の成分が増強される。このため、スピーカー１０の正面に障害物がある環境下でも、当該所定の周波数帯域内における音量低下を低減することができる。そのうえ、放音面２１ａからの音の周波数成分のうち、音声信号の所定の周波数帯域を超える成分が減衰される。このため、スピーカー１０の高調波歪みにより発生する音を低減することもできる。以上より、Ｓ／Ｎ比が改善されるので、スピーカー１０の正面に障害物がある環境下でも、スピーカー１０からの音声を聞き取りやすくすることができる。 In the above speaker 10, among the frequency components of the sound from the sound emitting surface 21a, the components within the predetermined frequency band of the audio signal are enhanced. Therefore, even in an environment where there is an obstacle in front of the speaker 10, it is possible to reduce the volume decrease in the predetermined frequency band. Moreover, among the frequency components of the sound from the sound emitting surface 21a, the components exceeding a predetermined frequency band of the audio signal are attenuated. Therefore, the sound generated by the harmonic distortion of the speaker 10 can be reduced. From the above, since the S / N ratio is improved, it is possible to make it easier to hear the sound from the speaker 10 even in an environment where there is an obstacle in front of the speaker 10.
　ここで、スピーカー１０は、放音ユニット２０とキャビネット３０と板状の音響部材４０とを有する。放音ユニット２０は、放音する放音面２１ａを有するコーン型の振動板２１を含む。キャビネット３０は、放音面２１ａを外部空間に露出させた状態で放音ユニット２０が取り付けられる。音響部材４０は、１つの開口部４１とともにヘルムホルツ共鳴器を構成する空間Ｓ１を放音面２１ａとの間に形成するように配置された状態でキャビネット３０に取り付けられる。 Here, the speaker 10 has a sound emitting unit 20, a cabinet 30, and a plate-shaped acoustic member 40. The sound emitting unit 20 includes a cone-shaped diaphragm 21 having a sound emitting surface 21a for emitting sound. The sound emitting unit 20 is attached to the cabinet 30 with the sound emitting surface 21a exposed to the external space. The acoustic member 40 is attached to the cabinet 30 in a state where the space S1 constituting the Helmholtz resonator is arranged between the sound emitting surface 21a and the sound emitting surface 21a together with one opening 41.
　このように、本実施形態の振動板２１は、コーン型である。このため、板状等の部材を用いて音響部材４０を構成することができる。このため、音響部材４０が複雑な形状となったり、当該空間Ｓ１の必要な大きさを確保するためのスペーサー等の部材を別途用意したりしなくて済む。また、スピーカー１０の小型化等を図ることができる。 As described above, the diaphragm 21 of the present embodiment is a cone type. Therefore, the acoustic member 40 can be configured by using a plate-shaped member or the like. Therefore, it is not necessary for the acoustic member 40 to have a complicated shape or to separately prepare a member such as a spacer for securing the required size of the space S1. Further, the size of the speaker 10 can be reduced.
　本実施形態の音響部材４０は、板状の蓋部材である。このため、音響部材４０の形状が箱状等の複雑な形状である場合に比べて、音響部材４０の製造および取付等が容易となる。 The acoustic member 40 of this embodiment is a plate-shaped lid member. Therefore, as compared with the case where the shape of the acoustic member 40 is a complicated shape such as a box shape, the manufacturing and mounting of the acoustic member 40 can be facilitated.
　また、音響部材４０の厚さは、開口部４１に向かって厚くなる。このため、音響部材４０の板厚を利用してヘルムホルツ共鳴器の首の長さｌを長くすることができる。この結果、音響部材４０の製造が容易となる。また、取り付けに用いられる音響部材４０の外周部の厚さが薄くなるので、音響部材４０の取り付けに関する構成が簡素化される。 Further, the thickness of the acoustic member 40 increases toward the opening 41. Therefore, the neck length l of the Helmholtz resonator can be lengthened by utilizing the plate thickness of the acoustic member 40. As a result, the acoustic member 40 can be easily manufactured. Further, since the thickness of the outer peripheral portion of the acoustic member 40 used for attachment is reduced, the configuration relating to the attachment of the acoustic member 40 is simplified.
　ここで、開口部４１は、音響部材４０と振動板２１とが重なる方向（Ｚ１方向またはＺ２方向）からみて、振動板２１の中心ＰＣを包含する１つの開口部である。このため、音響部材４０に設ける開口部の数が複数である場合に比べて、開口部４１の断面積を大きくしやすい。このため、ヘルムホルツ共鳴器の共鳴周波数ｆ０を高くしやすいという利点がある。 Here, the opening 41 is one opening including the central PC of the diaphragm 21 when viewed from the direction in which the acoustic member 40 and the diaphragm 21 overlap (Z1 direction or Z2 direction). Therefore, it is easy to increase the cross-sectional area of the openings 41 as compared with the case where the acoustic member 40 is provided with a plurality of openings. Therefore, there is an advantage that the resonance frequency f 0 of the Helmholtz resonator can be easily increased.
　２．第２実施形態
　以下、本発明の第２実施形態について説明する。以下に例示する形態において作用や機能が第１実施形態と同様である要素については、第１実施形態の説明で使用した符号を流用して各々の詳細な説明を適宜に省略する。 2. Second Embodiment Hereinafter, the second embodiment of the present invention will be described. For the elements whose actions and functions are the same as those of the first embodiment in the embodiments illustrated below, the reference numerals used in the description of the first embodiment will be diverted and detailed description of each will be omitted as appropriate.
　図７は、第２実施形態における音響部材４０Ａの平面図である。図８は、図７中のＡ２－Ａ２線断面図である。音響部材４０Ａは、１つの開口部４１に代えて複数の開口部４１Ａを有するとともに厚さが異なる以外は、前述の第１実施形態の音響部材４０Ａと同様である。 FIG. 7 is a plan view of the acoustic member 40A in the second embodiment. FIG. 8 is a cross-sectional view taken along the line A2-A2 in FIG. The acoustic member 40A is the same as the acoustic member 40A of the first embodiment described above, except that it has a plurality of openings 41A instead of one opening 41 and the thickness is different.
　具体的に説明すると、図７に示すように、音響部材４０Ａは、複数の開口部４１Ａを有する。当該複数の開口部４１Ａは、音響部材４０Ａと前述の放音面２１ａとの間の空間Ｓ１とともにヘルムホルツ共鳴器を構成する。ここで、当該複数の開口部４１Ａの合計の断面積が前述の断面積ｓに相当する。 Specifically, as shown in FIG. 7, the acoustic member 40A has a plurality of openings 41A. The plurality of openings 41A form a Helmholtz resonator together with the space S1 between the acoustic member 40A and the sound emitting surface 21a described above. Here, the total cross-sectional area of the plurality of openings 41A corresponds to the above-mentioned cross-sectional area s.
　図７に示す例では、当該複数の開口部４１Ａは、千鳥状に規則的に配置される。また、各開口部４１Ａは、平面視で円形をなす。なお、複数の開口部４１Ａの配置は、行列状等の他の規則的な配置でもよいし、ランダムであってもよい。ただし、複数の開口部４１Ａの配置が規則的である場合、複数の開口部４１Ａの配置がランダムである場合に比べて、音響部材４０Ａの設計が容易である。また、各開口部４１Ａの平面視形状は、円形に限定されず、例えば、三角形、四角形、五角形または六角形等の多角形でもよいし、スリット状、星形または楕円形等でもよい。さらに、開口部４１Ａの数は、図７に示す数に限定されず、任意である。また、複数の開口部４１Ａの大きさは、互いに異なってもよい。 In the example shown in FIG. 7, the plurality of openings 41A are regularly arranged in a staggered pattern. Further, each opening 41A has a circular shape in a plan view. The arrangement of the plurality of openings 41A may be another regular arrangement such as a matrix, or may be random. However, when the arrangement of the plurality of openings 41A is regular, the design of the acoustic member 40A is easier than when the arrangement of the plurality of openings 41A is random. Further, the plan view shape of each opening 41A is not limited to a circle, and may be, for example, a polygon such as a triangle, a quadrangle, a pentagon or a hexagon, or a slit shape, a star shape or an ellipse shape. Further, the number of openings 41A is not limited to the number shown in FIG. 7, and is arbitrary. Further, the sizes of the plurality of openings 41A may be different from each other.
　図８に示すように、音響部材４０ＡにおけるＺ２方向を向く面には、凹部４６および４７が設けられる。このため、凹部４６および４７を省略した場合に比べて、空間Ｓ１の体積を大きくすることができる。また、Ｚ軸に沿う各開口部４１Ａの長さを小さくすることができる。ここで、凹部４６の幅Ｗ１は、凹部４７の幅Ｗ２よりも大きい。また、凹部４６を囲む壁部４５Ａは、前述の凸部４５と同様、キャビネット３０に対する音響部材４０の位置ずれを防止する。 As shown in FIG. 8, recesses 46 and 47 are provided on the surface of the acoustic member 40A facing the Z2 direction. Therefore, the volume of the space S1 can be increased as compared with the case where the recesses 46 and 47 are omitted. Further, the length of each opening 41A along the Z axis can be reduced. Here, the width W1 of the recess 46 is larger than the width W2 of the recess 47. Further, the wall portion 45A surrounding the concave portion 46 prevents the acoustic member 40 from being displaced with respect to the cabinet 30 as in the case of the convex portion 45 described above.
　以上の第２実施形態によっても、前述の第１実施形態と同様の効果を得ることができる。また、本実施形態の音響部材４０Ａは、複数の開口部４１Ａを有するので、各開口部４１Ａを指等が入らない大きさとすることができる。このため、音響部材４０Ａの設置時等における振動板２１の損傷を低減することができる。 The same effect as that of the above-mentioned first embodiment can be obtained also by the above-mentioned second embodiment. Further, since the acoustic member 40A of the present embodiment has a plurality of openings 41A, each opening 41A can be sized so that a finger or the like cannot enter. Therefore, it is possible to reduce damage to the diaphragm 21 when the acoustic member 40A is installed.
　３．応用例
　図９は、聴取空間Ｓ２と遮蔽物２００により隔てられる空間Ｓ３にスピーカー１０が設置される場合を説明するための概念図である。聴取空間Ｓ２は、ユーザーＵが存在する空間である。空間Ｓ３は、スピーカー１０が設置される空間である。遮蔽物２００は、聴取空間Ｓ２と空間Ｓ３との間を隔てる構造体である。図９に示す例では、遮蔽物２００が空間Ｓ３を囲む形状をなす。また、遮蔽物２００には、複数の孔２０１が設けられる。 3. 3. Application Example FIG. 9 is a conceptual diagram for explaining a case where the speaker 10 is installed in the listening space S2 and the space S3 separated by the shield 200. The listening space S2 is a space in which the user U exists. Space S3 is a space in which the speaker 10 is installed. The shield 200 is a structure that separates the listening space S2 and the space S3. In the example shown in FIG. 9, the shield 200 has a shape surrounding the space S3. Further, the shield 200 is provided with a plurality of holes 201.
　ここで、スピーカー１０からの音は、各孔２０１を介して空間Ｓ３から聴取空間Ｓ２へ伝わる。しかし、遮蔽物２００の意匠的な都合上からスピーカー１０の正面に孔２０１を配置することができない場合がある。この場合でも、スピーカー１０において前述のようにヘルムホルツ共鳴器による音圧の調整が行われるので、ユーザーＵがスピーカー１０からの音声を聞き取りやすい。 Here, the sound from the speaker 10 is transmitted from the space S3 to the listening space S2 through each hole 201. However, due to the design of the shield 200, it may not be possible to arrange the hole 201 in front of the speaker 10. Even in this case, since the sound pressure is adjusted by the Helmholtz resonator in the speaker 10 as described above, the user U can easily hear the sound from the speaker 10.
　図１０は、スピーカー１０が車両１００に設置される場合を説明するための図である。図１０では、車両１００のインストルメントパネル１０１の内側にスピーカー１０が設置される場合が示される。このようにスピーカー１０を有する車両１００では、インストルメントパネル１０１の内側にスピーカー１０を配置しても、スピーカー１０からの音声を聞き取りやすくすることができる。このため、インストルメントパネル１０１のデザインの自由度が増すので、意匠性に優れる車両１００を提供することができる。 FIG. 10 is a diagram for explaining a case where the speaker 10 is installed in the vehicle 100. FIG. 10 shows a case where the speaker 10 is installed inside the instrument panel 101 of the vehicle 100. In the vehicle 100 having the speaker 10 in this way, even if the speaker 10 is arranged inside the instrument panel 101, the sound from the speaker 10 can be easily heard. Therefore, since the degree of freedom in designing the instrument panel 101 is increased, it is possible to provide the vehicle 100 having excellent design.
　４．変形例
　本発明は前述の各実施形態に限定されるものではなく、以下に述べる各種の変形が可能である。また、各実施形態及び各変形例を適宜組み合わせてもよい。 4. Modifications The present invention is not limited to the above-described embodiments, and various modifications described below are possible. Moreover, each embodiment and each modification may be combined appropriately.
　４－１．変形例１
　前述の形態では、音響部材４０または４０Ａがキャビネット３０に直接取り付けられる構成が例示されるが、この例示に限定されない。例えば、キャビネット３０と音響部材４０との間に枠状のスペーサーを配置してもよい。この場合、当該スペーサーの厚さまたは径により、空間Ｓ１の体積を調整し、所望の共鳴周波数ｆ０を得ることができる。 4-1. Modification 1
In the above-described embodiment, the configuration in which the acoustic member 40 or 40A is directly attached to the cabinet 30 is exemplified, but the present invention is not limited to this example. For example, a frame-shaped spacer may be arranged between the cabinet 30 and the acoustic member 40. In this case, the volume of the space S1 can be adjusted according to the thickness or diameter of the spacer, and a desired resonance frequency f 0 can be obtained.
　４－２．変形例２
　前述の形態では、音響部材４０または４０Ａが板状をなす場合が例示されるが、この例示に限定されない。例えば、音響部材がトレイ状をなしてもよい。 4-2. Modification 2
In the above-described embodiment, the case where the acoustic member 40 or 40A has a plate shape is exemplified, but the present invention is not limited to this example. For example, the acoustic member may be in the shape of a tray.
　４－３．変形例３
　前述の形態では、音響部材４０または４０Ａがキャビネット３０とは別体であるが、これに限定されず、音響部材４０または４０Ａがキャビネット３０と一体でもよい。 4-3. Modification 3
In the above-described embodiment, the acoustic member 40 or 40A is separate from the cabinet 30, but the present invention is not limited to this, and the acoustic member 40 or 40A may be integrated with the cabinet 30.
　５．付記
　以上に例示する形態または変形例から、例えば以下の態様が把握される。 5. Addendum For example, the following aspects can be grasped from the above-exemplified forms or modifications.
　本発明の好適な態様（第１態様）に係るスピーカーは、放音する放音面を有する振動板と、所定の周波数帯域に制限された音声を示す音声信号に基づいて、前記振動板を駆動する駆動部と、少なくとも１つの開口部を有し、前記放音面との間に前記少なくとも１つの開口部とともにヘルムホルツ共鳴器を構成する空間を形成するように配置される音響部材と、を有し、前記ヘルムホルツ共鳴器は、前記放音面からの音の周波数成分のうち、前記所定の周波数帯域内の成分を増強させるとともに、前記所定の周波数帯域を超える成分を減衰させる。 The speaker according to a preferred embodiment (first aspect) of the present invention drives the vibrating plate based on a vibrating plate having a sound emitting surface for emitting sound and an audio signal indicating sound limited to a predetermined frequency band. A driving unit and an acoustic member having at least one opening and arranged so as to form a space forming a Helmholtz resonator together with the at least one opening between the sound emitting surface and the sound emitting surface. Then, the Helmholtz resonator enhances the frequency component of the sound from the sound emitting surface within the predetermined frequency band and attenuates the component exceeding the predetermined frequency band.
　以上の態様によれば、放音面からの音の周波数成分のうち、音声信号の所定の周波数帯域内の成分が増強される。このため、スピーカーの正面に障害物がある環境下でも、当該所定の周波数帯域内における音量低下を低減することができる。そのうえ、放音面からの音の周波数成分のうち、音声信号の所定の周波数帯域を超える成分が減衰される。このため、スピーカーの高調波歪みにより発生する音を低減することもできる。以上より、Ｓ／Ｎ比が改善されるので、スピーカーの正面に障害物がある環境下でも、スピーカーからの音声を聞き取りやすくすることができる。 According to the above aspect, among the frequency components of the sound from the sound emitting surface, the components within the predetermined frequency band of the audio signal are enhanced. Therefore, even in an environment where there is an obstacle in front of the speaker, it is possible to reduce the volume decrease in the predetermined frequency band. Moreover, among the frequency components of the sound from the sound emitting surface, the components exceeding a predetermined frequency band of the audio signal are attenuated. Therefore, it is possible to reduce the sound generated by the harmonic distortion of the speaker. From the above, since the S / N ratio is improved, it is possible to make it easier to hear the sound from the speaker even in an environment where there is an obstacle in front of the speaker.
　第１態様の好適例（第２態様）において、前記振動板は、コーン型である。以上の態様によれば、板状等の部材を用いて音響部材を構成することができる。このため、音響部材が複雑な形状となったり、当該空間の必要な大きさを確保するためのスペーサー等の部材を別途用意したりしなくて済む。また、スピーカーの小型化等を図ることができる。 In the preferred example of the first aspect (second aspect), the diaphragm is a cone type. According to the above aspect, the acoustic member can be configured by using a member such as a plate. Therefore, it is not necessary for the acoustic member to have a complicated shape or to separately prepare a member such as a spacer for securing the required size of the space. In addition, the size of the speaker can be reduced.
　第２態様の好適例（第３態様）において、前記音響部材は、板状の蓋部材である。以上の態様によれば、音響部材の形状が箱状等の複雑な形状である場合に比べて、音響部材の製造および取付等が容易となる。 In the preferred example of the second aspect (third aspect), the acoustic member is a plate-shaped lid member. According to the above aspects, the manufacturing and mounting of the acoustic member becomes easier than in the case where the shape of the acoustic member is a complicated shape such as a box shape.
　第３態様の好適例（第４態様）において、前記音響部材の厚さは、前記少なくとも１つの開口部に向かって厚くなる。以上の態様によれば、音響部材の板厚を利用してヘルムホルツ共鳴器の首の長さを長くすることができる。この結果、音響部材の製造が容易となる。また、取り付けに用いられる音響部材の外周部の厚さを薄くすることができ、この結果、音響部材の取り付けに関する構成が簡素化される。 In a preferred example of the third aspect (fourth aspect), the thickness of the acoustic member increases toward at least one opening. According to the above aspect, the neck length of the Helmholtz resonator can be increased by utilizing the plate thickness of the acoustic member. As a result, the manufacturing of the acoustic member becomes easy. Further, the thickness of the outer peripheral portion of the acoustic member used for attachment can be reduced, and as a result, the configuration related to the attachment of the acoustic member is simplified.
　第１態様から第４態様のいずれかの好適例（第５態様）において、前記少なくとも１つの開口部は、前記音響部材と前記振動板とが重なる方向からみて、前記振動板の中心を包含する１つの開口部である。以上の態様によれば、開口部の数が複数である場合に比べて、開口部の断面積を大きくしやすい。このため、ヘルムホルツ共鳴器の共鳴周波数を高くしやすいという利点がある。 In any of the preferred examples (fifth aspect) of the first to fourth aspects, the at least one opening includes the center of the diaphragm when viewed from the direction in which the acoustic member and the diaphragm overlap. It is one opening. According to the above aspect, it is easy to increase the cross-sectional area of the openings as compared with the case where the number of openings is a plurality. Therefore, there is an advantage that the resonance frequency of the Helmholtz resonator can be easily increased.
　第１態様から第４態様のいずれかの好適例（第６態様）において、前記少なくとも１つの開口部は、複数の開口部である。以上の態様によれば、開口部を指等が入らない大きさとすることができる。このため、音響部材の設置時等における振動板の損傷を低減することができる。 In any of the preferred examples (sixth aspect) of the first to fourth aspects, the at least one opening is a plurality of openings. According to the above aspect, the opening can be sized so that a finger or the like cannot enter. Therefore, damage to the diaphragm at the time of installation of the acoustic member can be reduced.
　本発明の好適な態様（第７態様）に係るスピーカーは、放音する放音面を有するコーン型の振動板を含む放音ユニットと、前記放音面を外部空間に露出させた状態で前記放音ユニットが取り付けられるキャビネットと、少なくとも１つの開口部を有し、前記キャビネットに取り付けられる板状の音響部材と、を有し、前記音響部材は、前記少なくとも１つの開口部とともにヘルムホルツ共鳴器を構成する空間を前記放音面との間に形成するように配置される。 The speaker according to a preferred embodiment (seventh aspect) of the present invention includes a sound emitting unit including a cone-shaped diaphragm having a sound emitting surface for emitting sound, and the sound emitting surface in a state of being exposed to an external space. It has a cabinet to which the sound emitting unit is mounted and a plate-shaped acoustic member having at least one opening and being attached to the cabinet, the acoustic member having a Helmholtz resonator together with the at least one opening. It is arranged so as to form a space to be formed between the sound emitting surface and the sound emitting surface.
　以上の態様によれば、ヘルムホルツ共鳴器により、放音面からの音の周波数成分のうち、音声信号の所定の周波数帯域内の成分を増強させるとともに、当該所定の周波数帯域を超える成分を減衰させることができる。このため、前述の第１態様と同様、Ｓ／Ｎ比が改善されるので、スピーカーの正面に障害物がある環境下でも、スピーカーからの音声を聞き取りやすくすることができる。 According to the above aspect, the Helmholtz resonator enhances the frequency component of the sound from the sound emitting surface within a predetermined frequency band of the audio signal, and attenuates the component exceeding the predetermined frequency band. be able to. Therefore, since the S / N ratio is improved as in the first aspect described above, it is possible to easily hear the sound from the speaker even in an environment where there is an obstacle in front of the speaker.
　第１態様から第７態様のいずれかの好適例（第８態様）において、前記ヘルムホルツ共鳴器の共鳴周波数は、２ＫＨｚ以上５ＫＨｚ以下の範囲内にある。以上の態様によれば、Ｓ／Ｎ比が改善されるので、スピーカーからの音声がより聞き取りやすくなる。 In any of the preferred examples (eighth aspect) of the first to seventh aspects, the resonance frequency of the Helmholtz resonator is in the range of 2 KHz or more and 5 KHz or less. According to the above aspect, since the S / N ratio is improved, the sound from the speaker becomes easier to hear.
　本発明の好適な態様（第９態様）に係る車両は、前述のいずれかの態様のスピーカーを有する。以上の態様によれば、インストルメントパネルまたはヘッドコンソール等のパネルの内側にスピーカーを配置しても、スピーカーからの音声を聞き取りやすくすることができる。このため、意匠性に優れる車両を提供することができる。 The vehicle according to the preferred aspect (9th aspect) of the present invention has the speaker of any of the above-mentioned aspects. According to the above aspect, even if the speaker is arranged inside the panel such as the instrument panel or the head console, the sound from the speaker can be easily heard. Therefore, it is possible to provide a vehicle having excellent design.
　第９態様の好適例（第１０態様）において、聴取空間と遮蔽物により隔てられる空間に当該スピーカーが設置される。以上の態様によれば、スピーカーからの音が遮蔽物により減衰した後に聴取空間で聴取されるので、本発明を適用することにより得られる効果が顕著である。 In the preferred example of the ninth aspect (tenth aspect), the speaker is installed in a space separated from the listening space by a shield. According to the above aspect, since the sound from the speaker is attenuated by the shield and then heard in the listening space, the effect obtained by applying the present invention is remarkable.
１０…スピーカー、２０…放音ユニット、２１…振動板、２１ａ…放音面、２２…駆動部、３０…キャビネット、４０…音響部材、４０Ａ…音響部材、４１…開口部、４１Ａ…開口部、５０…ヘルムホルツ共鳴器、１００…車両、１０１…インストルメントパネル、２００…遮蔽物、ＣＰ…中心、ＰＣ…中心、Ｓ０…空間、Ｓ１…空間、Ｓ２…聴取空間、Ｓ３…空間、ｆ０…共鳴周波数、ｔ１…厚さ、ｔ２…厚さ。 10 ... speaker, 20 ... sound emitting unit, 21 ... diaphragm, 21a ... sound emitting surface, 22 ... driving unit, 30 ... cabinet, 40 ... acoustic member, 40A ... acoustic member, 41 ... opening, 41A ... opening, 50 ... Helmholtz resonator, 100 ... vehicle, 101 ... instrument panel, 200 ... shield, CP ... center, PC ... center, S0 ... space, S1 ... space, S2 ... listening space, S3 ... space, f 0 ... resonance Frequency, t1 ... thickness, t2 ... thickness.

Claims (10)

  1. 　放音する放音面を有する振動板と、
    　所定の周波数帯域に制限された音声を示す音声信号に基づいて、前記振動板を駆動する駆動部と、
    　少なくとも１つの開口部を有し、前記少なくとも１つの開口部とともにヘルムホルツ共鳴器を構成する空間を前記放音面との間に形成するように配置される音響部材と、を有し、
    　前記ヘルムホルツ共鳴器は、前記放音面からの音の周波数成分のうち、前記所定の周波数帯域内の成分を増強させるとともに、前記所定の周波数帯域を超える成分を減衰させる、
    　スピーカー。     A diaphragm with a sound emitting surface that emits sound,
    A drive unit that drives the diaphragm based on a voice signal indicating voice limited to a predetermined frequency band, and
    It has at least one opening, and an acoustic member arranged so as to form a space forming a Helmholtz resonator with the sound emitting surface together with the at least one opening.
    The Helmholtz resonator enhances the frequency components of the sound from the sound emitting surface within the predetermined frequency band, and attenuates the components exceeding the predetermined frequency band.
    speaker.
  2. 　前記振動板は、コーン型である、
    　請求項１に記載のスピーカー。     The diaphragm is cone-shaped.
    The speaker according to claim 1.
  3. 　前記音響部材は、板状の蓋部材である、
    　請求項２に記載のスピーカー。     The acoustic member is a plate-shaped lid member.
    The speaker according to claim 2.
  4. 　前記音響部材の厚さは、前記少なくとも１つの開口部に向かって厚くなる、
    　請求項３に記載のスピーカー。     The thickness of the acoustic member increases toward the at least one opening.
    The speaker according to claim 3.
  5. 　前記少なくとも１つの開口部は、前記音響部材と前記振動板とが重なる方向からみて、前記振動板の中心を包含する１つの開口部である、
    　請求項１から４のいずれか１項に記載のスピーカー。     The at least one opening is one opening that includes the center of the diaphragm when viewed from the direction in which the acoustic member and the diaphragm overlap.
    The speaker according to any one of claims 1 to 4.
  6. 　前記少なくとも１つの開口部は、複数の開口部である、
    　請求項１から４のいずれか１項に記載のスピーカー。     The at least one opening is a plurality of openings.
    The speaker according to any one of claims 1 to 4.
  7. 　放音する放音面を有するコーン型の振動板を含む放音ユニットと、
    　前記放音面を外部空間に露出させた状態で前記放音ユニットが取り付けられるキャビネットと、
    　少なくとも１つの開口部を有し、前記キャビネットに取り付けられる板状の音響部材と、を有し、
    　前記音響部材は、前記少なくとも１つの開口部とともにヘルムホルツ共鳴器を構成する空間を前記放音面との間に形成するように配置される、
    　スピーカー。     A sound emitting unit including a cone-shaped diaphragm having a sound emitting surface that emits sound, and
    A cabinet to which the sound emitting unit is mounted with the sound emitting surface exposed to the external space, and
    It has at least one opening and has a plate-shaped acoustic member attached to the cabinet.
    The acoustic member is arranged so as to form a space constituting the Helmholtz resonator together with the sound emitting surface together with the at least one opening.
    speaker.
  8. 　前記ヘルムホルツ共鳴器の共鳴周波数は、２ＫＨｚ以上５ＫＨｚ以下の範囲内にある、
    　請求項１から７のいずれか１項に記載のスピーカー。     The resonance frequency of the Helmholtz resonator is in the range of 2 KHz or more and 5 KHz or less.
    The speaker according to any one of claims 1 to 7.
  9. 　請求項１から８のいずれか１項に記載のスピーカーを有する、
    　車両。     The speaker according to any one of claims 1 to 8.
    vehicle.
  10. 　聴取空間と遮蔽物により隔てられる空間に当該スピーカーが設置される、
    　請求項９に記載の車両。     The speaker is installed in a space separated from the listening space by a shield.
    The vehicle according to claim 9.
PCT/JP2020/045865 2019-12-25 2020-12-09 Speaker and vehicle WO2021131705A1 (en)

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WO2024072534A1 (en) * 2022-09-28 2024-04-04 SimpliSafe, Inc. Speaker device
WO2024072790A1 (en) * 2022-09-28 2024-04-04 SimpliSafe, Inc. Speaker device

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WO2018061319A1 (en) * 2016-09-28 2018-04-05 株式会社村田製作所 Piezoelectric sound generating component
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JPH09215092A (en) * 1996-02-07 1997-08-15 Star Micronics Co Ltd Electroacoustic transducer
US20070280497A1 (en) * 2004-04-01 2007-12-06 Peter Isberg Communications Unit With Arrangement For Loud Reproduction Of Sound
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WO2024072534A1 (en) * 2022-09-28 2024-04-04 SimpliSafe, Inc. Speaker device
WO2024072790A1 (en) * 2022-09-28 2024-04-04 SimpliSafe, Inc. Speaker device

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