JP2022090000A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker capable of restraining a front chamber effect and excellently adjusting directional characteristics.

SOLUTION: A speaker includes: a vibrator (67); and a diffuser (9) positioned so that end parts (9c) on the side of the vibrator (67) face the vibrator (67). Each end part (9c) on the side of the vibrator (67) has a hollow part (E) where a distance from the vibrator (67) is smoothly changed in a circumferential direction. Alternatively, the speaker includes: the vibrator (67); and the diffuser (9) having annular base parts (9b) and positioned so that the end parts (9c) on the side of the vibrator (67) in the base parts face the vibrator (67). Each end part on the side of the vibrator (67) has a hollow part having a sine wave shape, a circular arcuate shape, or a triangular wave shape with a distance from the vibrator (67) larger than other parts.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a speaker and particularly relates to a speaker equipped with a diffuser.

In a cone-shaped diaphragm to which a center cap projecting forward at the center is attached, the peripheral portion of the center cap and its vicinity are recessed in an annular shape.
When a speaker equipped with this vibrating plate is operated, the output sound from the center cap and the output sound from the vibrating plate interfere with each other in the space immediately in front of the recess, and a peak or dip is generated at a specific frequency, resulting in a sound pressure frequency. It is known that the so-called anterior chamber effect (cavity effect), in which the characteristics are disturbed, occurs. This anterior chamber effect should be suppressed, and an example of the suppression technique is described in Patent Document 1.
On the other hand, in a speaker provided with a diaphragm to which the center cap is attached, a technique of arranging a diffuser for adjusting the directivity of the output sound on the front side of the center cap is known, and is described in Patent Document 2. Has been done.

Japanese Unexamined Patent Publication No. 2004-343804 Japanese Unexamined Patent Publication No. 2011-010056

The speaker diffuser described in Patent Document 2 has a limit in adjusting the directivity, and therefore improvement has been desired.

Therefore, an object to be solved by the present invention is to provide a speaker capable of satisfactorily adjusting the directivity.

In order to solve the above problems, the present invention has the following configuration.
It comprises a vibrating body and a diffuser located so that the vibrating body side end faces the vibrating body, and the vibrating body side end portion has a scooping portion in which the distance to the vibrating body smoothly changes in the circumferential direction. ..

According to the present invention, the effect that the directivity can be adjusted satisfactorily can be obtained.

FIG. 1 is a perspective view of a coaxial speaker 53 provided with a tweeter 51, which is an embodiment of the speaker according to the embodiment of the present invention. FIG. 2 is a cross-sectional view taken at the S2-S2 position in FIG. FIG. 3 is a perspective view of the front side of the diffuser base 8 included in the tweeter 51. FIG. 4 is a perspective view of the rear surface side of the diffuser base 8. FIG. 5 is a graph for explaining the circumferential height of the bottom end portion 9c of the diffuser 9 of the diffuser base 8. FIG. 6 is a graph for explaining the difference in directivity depending on the presence or absence of the diffuser 9. FIG. 7 is a graph for explaining the difference in sound pressure frequency characteristics depending on the presence or absence of the cut portion E. FIG. 8 is a front view showing a speaker system 61 which is an embodiment of the speaker system according to the embodiment of the present invention. FIG. 9 is a front view showing a stereo speaker system 62 which is an example of the stereo speaker system according to the embodiment of the present invention. FIG. 10 is a schematic top view showing the vicinity of the driver's seat of an automobile. FIG. 11 is a schematic front view showing an in-vehicle stereo speaker system 51BS which is an example of an in-vehicle stereo speaker system according to an embodiment of the present invention. FIG. 12 is a graph for explaining a modified example of the hollowed portion E.

The speaker according to the embodiment of the present invention will be described with reference to the tweeter 51 which is the speaker of the embodiment.

(Example 1: tweeter 51)
FIG. 1 is a perspective view showing a coaxial speaker 53 equipped with a tweeter 51. The coaxial speaker 53 is a so-called coaxial 2-way speaker having a woofer 52 and a tweeter 51 coaxially attached to the woofer 52.
The woofer 52 has a frame 52a and a cone-shaped diaphragm 52c supported by the frame 52a via an edge 52b. Here, the cone shape means a shape that continuously expands in diameter from the root side to the tip side, such as a petal shape of a morning glory in addition to a cone shape.
For convenience of the following description, the anteroposterior direction is defined along the axis CL53 of the coaxial speaker 53 as shown in FIG.
In the coaxial speaker 53, the axis CL52 of the woofer 52 and the axis CL51 of the tweeter coincide with the axis CL53.

FIG. 2 is a vertical cross-sectional view of the tweeter 51, which is a cross-sectional view taken at the S2-S2 position in FIG. The tweeter 51 is a so-called dynamic speaker.
The tweeter 51 has a main body frame 1, and a magnetic circuit M including a yoke 2, a magnet 3, and a top plate 4.

The main body frame 1 has a central hole 1a and is substantially annular in shape, and is fixed to a support column 52d protruding forward from the central portion of the woofer 52.
The yoke 2 has a round pot shape, and is attached to the main body frame 1 by engaging the outer peripheral portion of the peripheral wall with the central hole 1a of the main body frame 1.
The magnet 3 has a disk shape and is fixed to the front surface of the bottom wall so as to form a predetermined radial gap between the magnet 3 and the peripheral wall of the yoke 2.
The top plate 4 has a disk shape and is attached to the front surface of the magnet 3.

The main body frame 1 supports a cone-shaped or morning glory petal-shaped diaphragm 6 so as to be movable back and forth via an edge 6a.
The diaphragm 6 has a fitting portion 6b in the center. Further, a spherical shell-shaped center cap 7 that is convex forward is attached to the diaphragm 6 so as to close the fitting portion 6b, and has a so-called balance dome shape. The diaphragm 6 and the center cap 7 emit sound by vibrating. When the center cap 7 has a convex shape in the forward direction, the center cap 7 and the diaphragm 6 form an annular valley portion Qa. In other words, the diaphragm 6 and the center cap 7 sandwich the valley Qa to form a vibrating body 67 for sound emission. The center cap 7 may have an integral structure with the diaphragm 6. Further, the center cap 7 may be adhered to the voice coil bobbin 5 and may have a distance from the diaphragm 6. The center cap 7 is not limited to the front convex shape, but may be the rearward convex shape.
Further, the front end portion of the cylindrical voice coil bobbin 5 is inserted into the fitting portion 6b of the diaphragm 6 and is attached so as to extend rearward. A voice coil 5a is wound around the rear end side of the voice coil bobbin 5.
The voice coil bobbin 5 around which the voice coil 5a is wound is arranged so as to be movable back and forth within the radial gap between the magnet 3 and the top plate 4 and the yoke 2.
When a voice signal is supplied to the voice coil, the voice coil bobbin 5 and the diaphragm 6 to which the voice coil bobbin 5 is attached vibrate back and forth by electromagnetic induction with the magnetic circuit M, and sound is output.

The inner peripheral edge of the fitting portion 6b of the diaphragm 6, that is, the outer peripheral edge of the center cap 7 and the front end position of the voice coil bobbin 5 are located in the vibrating body 67 of the balance dome in which the diaphragm 6 and the center cap 7 are combined. It is an annular valley part Qa corresponding to the valley bottom of the portion recessed on the rear side, which is also called a neck.

The tweeter 51 has a diffuser base 8 on the front side. The diffuser base 8 is attached to the front surface of the main body frame 1 in this example. The diffuser base 8 is made of, for example, a resin.
FIG. 3 is a perspective view of the diffuser base 8 viewed from diagonally forward, and FIG. 4 is a perspective view of the diffuser base 8 viewed from diagonally rearward.
As shown in FIGS. 2 to 4, the diffuser base 8 has a substantially annular plate shape, and is arranged in a sound emitting hole 8a having an inner diameter D8b larger than the outer diameter D5b of the diaphragm 6 and in the sound emitting hole 8a. It has a diffuser 9 connected and supported by a support arm 10 with respect to the inner peripheral portion of the sound emitting hole 8a. Further, the diffuser base 8 has an outer peripheral end 8b that is folded back to form a flange, and the sound emitting hole 8a to the outer peripheral end 8b are connected by a slope. Here, the slope may be a straight line or may have a curvature in the vertical cross-sectional shape.
In this example, three support arms 10 are provided around the axis CL51 at a pitch of 120 °.

The diffuser 9 has a disc-shaped front end portion 9d having a central hole 9a centered on the axis CL91, and a base portion 9b formed in an umbrella shape extending rearward from the peripheral edge of the front end portion 9d. .. Here, the diffuser 9 may be composed of only the base portion 9b and may not have the front end portion 9d, and the front end portion 9d may not have a flat disk shape. The base portion 9b may have a cylindrical shape having no spread.
The axis CL9 (see FIG. 3) of the central hole 9a coincides with the axis CL51 of the tweeter 51 with the diffuser 9 attached to the main body frame 1.
The axis CL9 of the central hole 9a and the axis CL51 of the tweeter 51 do not have to match. If they do not match, the distance from an arbitrary point on the axis of the axis CL51 to the ridge of the central hole 9a changes around the axis CL51, so that sounds with different paths arrive on the axis, resulting in sound pressure frequency characteristics. The effect of smoothing peaks and dips can be obtained.
The inner surface 9b1 of the base portion 9b has a corner portion between the disc-shaped front end portion 9d and the umbrella-shaped base portion 9b, and has a space between the arc-shaped center cap 7. It is composed of. It may be formed as a curved surface substantially along the center cap 7. Further, when the base portion 9b does not have an umbrella-like spread and has a cylindrical shape, the inner surface 9b1 is a surface substantially parallel to the axis CL91. The outer surface 9b2 is formed as a curved surface set so that the plate thickness is substantially the same as that of the inner surface 9b1.
The diffuser 9 may be a discontinuous substantially annular shape having a slit in a part instead of a circular ring that is continuously closed around the axis CL91. Further, it may be formed in an arc shape including a C shape having a large opening in the circumferential direction. In the following description, it will be described as a closed ring.

The base portion 9b is formed so that the radial position of the bottom end portion 9c, which is the rear end portion (rear end portion) thereof, is in front of the position corresponding to the annular valley portion Qa. Further, in the front-rear direction, at least the rear end side of the base portion 9b is located in the front space Va of the annular valley portion Qa.
The front space Va includes the outer peripheral edge of the diaphragm 6 and the apex of the center cap 7, whichever is on the rear side (lower side), and the plane orthogonal to the axis CL51 is defined as the reference plane LNb. It is defined as a space on the front side of the diaphragm 6 and the center cap 7 and on the rear side of the reference plane LNb. In FIG. 2, the reference plane LNb is shown by a chain line, and the cross section of the front space Va is shown in the region between the reference plane LNb and the vibrating body 67.
Then, a part of the base portion 9b of the diffuser 9 has entered the rear side of the reference plane LNb. That is, it is in the front space Va.

Further, the bottom end portion 9c, which is the rear side end portion of the base portion 9b, is not included in the same plane on the entire circumference, but is a hollow portion E which is partially cut forward.
In this example, the hollowed portion E is formed at three positions as recesses 9c1 to 9c3 as shown in FIGS. 3 and 4.

For ease of understanding, FIG. 5 will also be referred to.
FIG. 5 is a view in which the position in the front-rear direction of the bottom end portion 9c is developed in a plane with a circumference of 360 ° with the circumferential position Pa in FIG. 3 as 0 °. The position Pa in the circumferential direction is a position other than the hollowed portion E. That is, the horizontal axis is the circumferential position with the circumferential position Pa around the axis CL9 as the base point, and the vertical axis is the forward direction with the bottom end 9c of the circumferential position Pa as the reference height LNa (see FIG. 2). It is the cutting height H, which is the amount of denting. As shown in FIG. 5, the cutting height H of the recesses 9c1 to 9c3 is set to Ha at the maximum.
The larger the cutting height H on the vertical axis, the stronger the cutting degree. When the cutting height H exceeds the width of the base portion 9b in the axial direction, the base portion 9b is divided and a slit is formed. When there are a plurality of slits formed by the cut portion E, the support arm 10 is arranged so as to support the plurality of base portions 9b divided by the slits.
Further, in the cutting portion E, the circumferential distance at which the cutting height H is a positive value is defined as the cutting width W.

In the tweeter 51 described above, the diffuser 9 is arranged close to the annular valley portion Qa while the bottom end portion 9c enters the front space Va.
As a result, the base portion 9b of the diffuser 9 functions as a separation wall that divides the front space Va into the center cap 7 side and the cone-shaped side of the diaphragm 6.
Therefore, by suppressing the interference between the output sound from the center cap 7 and the output sound from the cone-shaped portion of the vibrating plate 6, the occurrence of peak dips at a specific frequency is reduced, and the sound pressure of the output sound is reduced. Disturbance of frequency characteristics is less likely to occur. That is, the anterior chamber effect is suppressed.

However, when it does not have the scooped portion E, the diffuser 9 also operates as an acoustic tube and has a single resonance frequency because the height of the base portion 9b in the front-rear direction is uniform. Therefore, the output sound is emphasized in a specific frequency region, and a peak is generated to cause disturbance in the frequency characteristics.
Therefore, by providing one or more hollowed portions E in the diffuser 9, the resonance frequency caused by the height and diameter of the cylindrical base portion 9b in the front-rear direction is dispersed, and the peak of the output sound can be suppressed. When a plurality of hollowed portions E are provided, the resonance frequency of the cylindrical base portion 9b is dispersed, so that the directivity is improved.

When the cut portion E has a rectangular shape, the height of the base portion 9b is two types other than the cut portion E and the cut portion E. Therefore, the resonance frequency is also only two points, and the frequency characteristic has two peaks. Therefore, the shape of the hollowed portion E is preferably a shape that further disperses the resonance frequency, such as a sine wave shape, a triangular wave shape, or an arc shape. Further, it is more preferable that the points other than the hollowed portion E are not uniform in the height direction. In the sound pressure frequency characteristic of the tweeter 51, this is not limited to the case where the frequency of the peak or dip in question is related to these two resonance frequencies, and it may be preferable to use the rectangular hollow portion E.
The arrangement of the cutting portion E is not limited to the rear end portion of the diffuser 9, and may be the front end portion. The resonance frequency due to the acoustic tube effect can be dispersed as in the case of being arranged at the rear end, and the effect as a protective wall to prevent the interference between the output sound of the center cap 7 and the diaphragm 6 is the valley Qa. Since the distance is short, more effects can be obtained.

Further, the degree of proximity between the diffuser 9 and the annular valley Qa is such that the distance between the bottom end portion 9c without the hollowed portion E and the annular valley Qa in the front-rear direction has the maximum amplitude rated by the tweeter 51. Is set to the minimum within the range that does not interfere with the amplitude of the diaphragm when is input. As a result, the function of the base 9b as a separation wall is maximized, and the anterior chamber effect is further suppressed.

As described above, since the tweeter 51 has the diffuser 9, the interference between the output sound from the center cap 7 and the output sound from the cone-shaped portion of the diaphragm 6 is satisfactorily suppressed. This interference suppression reduces energy loss due to cancellation of output sounds at angles different from the sound emission axis direction, so that the sound pressure of the output sound increases in all directions and the directional characteristics of the output sound become wider. More specifically, the directivity is widened not only in the plane perpendicular to the axis CL51 but also in the range of the solid angle in the direction of the cut portion E from the axis CL51.

FIG. 6 is a graph illustrating the difference in directivity depending on the presence or absence of the diffuser 9, for example, the characteristics at 14.5 kHz when the outer circumference of the diaphragm 6 is about 25 mm.
In FIG. 6, the solid line shows the directivity of the tweeter 51, that is, the directivity when the diffuser 9 is provided, and the broken line shows the directivity of the speaker when the diffuser 9 is not present. The front of the axis CL51, which is the front surface, is set to 0 °.

As shown in FIG. 6, the directivity is widened by attaching the diffuser 9, and the improvement of the directivity is particularly remarkable in a region wider than 40 °.
This result is obtained with the same tendency at 14 kHz to 20 kHz.

Here, the state of interference between the sound from the center cap 7 and the sound from the cone-shaped diaphragm 6 differs between the angle range in which the scooped portion E in the vicinity of the diffuser 9 is arranged and the angle range in which the cut portion E is not arranged, and the axis line. The state of interference changes around CL9. Thereby, the diffuser 9 has the hollow portion E at the bottom end portion 9c, so that the degree of interference of the sound reaching the axis CL9 of the sound emitted from the tweeter 51 can be adjusted. Thereby, the directivity characteristic of the output sound of the tweeter 51 can be adjusted according to the position where the cutting portion E is provided, the number of the cutting portions E provided, and the shape of the cutting portion E. Further, it is possible to suppress the peak and dip of the sound pressure frequency characteristic in the axis CL51 of the tweeter 51. Since the distance from an arbitrary point on the axis of the axis CL51 to the ridge of the central hole 9a changes around the axis CL51, sounds with different paths arrive on the axis to smooth the peaks and dips of the sound pressure frequency characteristics. The effect of becoming is obtained.

FIG. 7 is a sound pressure frequency characteristic of 10 kHz to 20 kHz in front of the front axis CL53 depending on the presence or absence of the cut portion E.
The solid line is the characteristic of the tweeter 51 with the cutting portion E, and the broken line is the characteristic when the diffuser 9 of the tweeter 51 is replaced with the diffuser having the shape of the base 9b without the cutting portion E.

As shown in FIG. 7, by providing the hollow portion E, it is possible to improve the sound pressure particularly in the high frequency range of 16 kHz or higher.
This is because the base portion 9b of the diffuser 9 reduces the interference between the sound emitted from the center cap 7 and the sound emitted from the diaphragm 6 in the vicinity of the diffuser 9, thereby suppressing the anterior chamber effect, and the cutting portion E on the axis CL53. Due to the change in the reaching sound in, the sound pressure in the high frequency range from the center cap 7 increases.

(Embodiment 2: Speaker system 61)
Generally, when listening to the output sound on the front (front) side of the speaker system in which the speaker is mounted in the enclosure, if the directivity of the high frequency range is wide on the upper side (top of the head), the listening sound field is on the upper side. It is known to be widespread, especially good for listening to music.
Therefore, it is preferable to adopt a speaker provided with a diffuser 9 for the speaker system, and attach the speaker to the enclosure so that the hollowed portion E is on the upper side (top side) in the used state.

FIG. 8 is a front view (front view) showing the speaker system 61 as an example thereof. The speaker system 61 is a so-called two-way speaker having an enclosure 61a which is an acoustic box, a woofer 61b attached to the enclosure 61a, and a tweeter 51A.
The tweeter 51A has the same structure as the tweeter 51, and is attached to the enclosure 61a in a posture in which one of the hollowed portions E of the diffuser 9 faces upward (indicated by an arrow) in the usage posture.

In the speaker system 61, at least in the high frequency range of the output sound, the upward sound pressure is increased and the upper side is enriched as a directivity characteristic.
As a result, the listener who listens to the output sound from the front (front) can feel a good sound field with a spatial expanse because the sound image is clear and localized upward.

(Example 3: Stereo speaker system)
For the reproduction of stereo sound, the speaker system 61 of the second embodiment can be paired to form a stereo speaker system.
Further, a pair of speakers may be provided in one enclosure to form a stereo speaker system.
FIG. 9 is a front view showing an example of the stereo speaker system 62.
The stereo speaker system 62 includes a pair of left and right speakers 51A in the enclosure 62a. Then, in each speaker 51A, one of the scooping portions E of the diffuser 9 is
The mounting posture with respect to the enclosure 62a is determined so as to be located above (indicated by an arrow) in the usage posture of the stereo speaker system 62.
In these stereo speaker systems, the listener can feel a stereo sound field having a three-dimensional expanse due to the high sound pressure in the high frequency range upward.

(Embodiment 4: In-vehicle stereo speaker system)
A stereo speaker system, which is a set of speakers whose directivity is adjusted according to the formation position of the hollow portion E, is also useful for in-vehicle use. This will be described with reference to FIGS. 10 and 11.
FIG. 10 is a schematic top view showing the vicinity of the driver's seat of an automobile.
FIG. 11 is a diagram illustrating an in-vehicle stereo speaker system 51BS.

The in-vehicle stereo speaker system 51BS is configured as a set of a left speaker 51BL and a right speaker 51BR. The speakers 51BL and 51BR may be tweeters and may be separate speaker systems combined with a woofer.
The speaker 51BL and the speaker 51BR differ only in the circumferential position of the cutting portion E, and have the same structure in other parts.
An example of the installation mode of the speakers 51BL and 51BR in which the driver D in the vehicle interior can obtain the effect of the directivity expansion by the cutting portion E is as follows. Of course, the installation mode is not limited to the following examples.
When the driver's body axis (parallel to the top and bottom axis of the vehicle) is the A axis, the axis perpendicular to the A axis, the axis passing through the height of the driver D's ear is the B axis, and the axis perpendicular to the B axis is the C axis. To. The sound emission axis of the speakers 51BL and 51BR is set as the C axis in order to direct the cut portion E of the speakers 51BL or 51BR toward the ears of the driver D in the vehicle interior. For example, when the speaker 51BL or the speaker 51BR is arranged vertically upward on the dashboard of the vehicle, the sound emitting direction is parallel to the A axis. Here, if the B axis perpendicular to the A axis is the front-rear direction of the vehicle, the C axis perpendicular to the B axis coincides with the sound emission axis as the top and bottom axis of the vehicle. In this relationship, the effect of expanding the directivity can be obtained by directing the gouged portion E of the speaker 51BL or 51BR toward the ear of the driver D.
As described above, the effect of the cutting portion E spreads the directivity to the solid angle in the direction of the cutting portion E, so that the sound image is obtained even when the height of the speaker 51BL or 51BR is different from the height of the ear of the driver D. You can get a sense of spaciousness.
As shown in FIGS. 10 and 11, in the vehicle, the left speaker 51BL mounted upward on the mounted member on the left side with respect to the driver D (the left side of the dashboard DB in this example) has an output sound of driving. A hollow portion E is provided at an angle θLa corresponding to the angle θL toward the left ear De1 of the person D, and is adjusted so that the sound pressure in the high frequency range is enhanced in the angle θLa direction.
On the other hand, the right speaker 51BR mounted upward on the mounted member on the right side with respect to the driver D (in this example, the right side of the dashboard DB) corresponds to the angle θR toward the right ear De2 of the driver D who is the listener. A hollow portion E is provided at the angle θRa, and is adjusted so that the sound pressure of high-pitched sound is enhanced in the direction of the angle θRa.
In the case of a right-hand drive vehicle, the angles θL and θLa are smaller than the angles θR and θRa. The opposite is true for left-hand drive vehicles.

The left speaker 51BL is provided with a hollow portion E at a position deviated by an angle θLa in the counterclockwise direction with respect to the rear of the installation posture when viewed from the upper surface. Further, the right speaker 51BR is provided with a hollow portion E at a position deviated by an angle θRa in the clockwise direction with respect to the rear of the installation posture when viewed from the upper surface.
As a result, the left and right speakers 51BL and 51BR output the sound whose output sound pressure in the high frequency range is mainly adjusted by the cutting portion E so as to aim at the left ear De1 and the right ear De2 of the driver D, respectively.
Therefore, the driver D can hear the sound of a good stereophonic image in which the treble range is well-balanced on the left and right even though he / she sits at a position biased to the left and right. When the diffuser 9 has three cutting portions E separately from the cutting portion E facing the user, for example, as in the first embodiment, the sound emitted from the other cutting portions E gives a sense of depth to the output sound. effective.

The mounted members of the speakers 51BL and 51BR in the vehicle include, for example, doors, window pillars, ceilings, and the like, in addition to the dashboard DB.

The embodiment described in detail above is not limited to the above-mentioned configuration, and may be a modified example that is modified within a range that does not deviate from the gist of the present invention.

The plurality of cutting portions E may independently set the cutting height H, the cutting width W, and the cutting shape, respectively. Representative examples of this are shown in FIGS. 12 (a) to 12 (C).

FIG. 12A is an example in which the shapes of the plurality of hollowed portions E are formed in a triangular shape. The cutting height H is described as an example in which the height Ha is equal to each other, but of course, they may be different.
Further, the deformed shape of the hollowed portion E is not limited to a triangular shape, and may be, for example, a sine wave shape. In the case of a sine wave shape, the sound pressure characteristic in the circumferential direction changes smoothly, and the change in the sound pressure characteristic in the circumferential direction at the same radial distance from the axis CL91 which is the sound emission axis becomes smooth in terms of hearing.
Further, the shape of the hollowed portion E may be rectangular, and in that case, the sound pressure characteristic in the circumferential direction can be changed sharply.

FIG. 12B shows an example in which a plurality of scooped portions E are continuously formed. In this example, the portion where the cutting height H is 0 (zero) is not linear but dotted in the figure. Of course, it may be partially linear.
FIG. 13C shows an example in which the cutting height H, the cutting width W, and the cutting shape of each of the plurality of cutting portions E are different. Of course, only some, but not all, may be different.
The shapes and the like illustrated in FIGS. 12 (a) to 12 (c) can be freely combined.

Further, the front end portion 9d, which is the upper end of the diffuser 9, may have a scooped portion that is scooped out rearward instead of having a flat shape.
Even if the front end portion 9d is provided with a hollow portion, the degree of interference between the output sound from the diaphragm 6 and the output sound from the center cap 7 can be adjusted to some extent, and the sound pressure frequency characteristic of the output sound of the tweeter 91 is released. The peak dip on the axis CL51, which is the sound axis, can be suppressed.

The output of the center cap 7 is obtained by providing a corner portion between the base portion 9b of the diffuser 9 and the disk-shaped front end portion 9d as the above-mentioned umbrella shape and providing a space between the base portion 9b and the arc-shaped center cap 7. It is possible to reduce the pressure applied to the vibration of the center cap 7 while giving the sound a diffusion effect. Since no pressure is applied to the vibration and the vibration is not suppressed, the sound pressure of the output sound from the center cap 7 is not suppressed and is emitted forward from the central hole 9a, so that the output sound pressure can be increased.
Depending on the output sound quality of the tweeter 91, the shape of the base 9b is not limited to an umbrella shape that covers the outer peripheral edge side of the center cap 7, and may be, for example, a cylinder shape having the same diameter or a cone shape that expands forward. ..

The number of support arms 10 connecting the diffuser base 8 and the diffuser 9 and the position in the circumferential direction are not limited to the above-mentioned three 120 ° pitches, and are set according to the specifications such as the usage environment and the sound field to be set. good.
The cone shape of the diaphragm 6 of the tweeter 91 has been described as a circular cone shape, but the shape is not limited to a circular shape. It may be oval.
Further, the diffuser 9 is not limited to being mounted on a tweeter for a high frequency range, and even if it is mounted on a speaker such as a squawker or a woofer or a full-range speaker, the anterior chamber effect is suppressed and the directional characteristic of the output sound is suppressed. The effect that the adjustment of is possible is obtained.

As the diaphragm 6, a cone-shaped diaphragm (including a morning glory petal-shaped diaphragm) has been described, but the diaphragm 6 is not limited to this.
If the vibrating body 67 has an annular valley Qa and an anterior chamber effect is generated, the effect of the diffuser 9 is exhibited, so that it is applicable.

1 Main body frame, 1a Central hole 2 York 3 Magnet 4 Top plate 5 Voice coil bobbin, 5a Voice coil, 5b Outer diameter 6 Diaphragm, 6a Edge, 6b Fitting part 7 Center cap 8 Diffuser base, 8a Sound release hole, 8b Outer circumference End 9 Diffuser 9a Central hole, 9b Base, 9b1 Inner surface 9b2 Outer surface, 9c Bottom end, 9c1-9c3 Recess 9d Front end 10 Support arm 51,51A Tweeter (speaker)
51BL, 51BR (Vehicle) Speaker 51BS (Vehicle) Stereo Speaker System 52 Wooha (Speaker)
52a frame, 52b edge, 52c diaphragm 52d prop 53 coaxial speaker 61 speaker system, 61a enclosure, 61b woofer 62 stereo speaker system, 62a enclosure 67 vibrating body CL51, CL52, CL53, CL9 axis D driver, De1 left ear, De2 Right ear D5b outer diameter, D8b inner diameter E scooping height, Ha height M magnetic circuit LNa reference height, LNb reference plane Pa circumferential position Qa annular valley TL, TR door Va front space W scooping width θL, θR, θLa, θRa angle

Claims (2)

Vibrating body and
The diffuser is provided so that the end portion on the vibrating body side faces the vibrating body.
The end portion on the vibrating body side is a speaker having a hollow portion in which the distance from the vibrating body smoothly changes in the circumferential direction. Vibrating body and
A diffuser having an annular base, wherein the end of the base on the vibrating body side is located so as to face the vibrating body.
The end portion on the vibrating body side is a speaker having a scooped portion having a sine wave shape and an arc shape or a triangular wavy shape in which the distance from the vibrating body is larger than the other portion.

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