JP2012109859A - Electro-acoustic transducer diaphragm and electro-acoustic transducer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-acoustic transducer diaphragm of which a resonance mode in the diaphragm is dispersed, and in which frequency characteristic is stabilized and flattened, and to provide an electro-acoustic transducer using the diaphragm.SOLUTION: In an electro-acoustic transducer diaphragm, a plurality of ribs are formed from the inside toward the periphery of the diaphragm at intervals, and at least one of the shapes, lengths, arrangements, and intervals of the ribs arranged sequentially along the circumferential direction of the diaphragm are different from each other, thereby obtaining an irregular rib pattern.

Description

  As a diaphragm for an electroacoustic transducer such as a microphone or a speaker, there are a circular shape and a track shape as shown in FIGS. Recently, many track-shaped electroacoustic transducers for space saving have been used for thin TVs.

  However, a diaphragm of an electroacoustic transducer such as a microphone or a speaker generates a resonance mode in the surface of the diaphragm, and this causes disturbance (fluctuation) of frequency characteristics.

  Conventionally, in order to solve this problem, as shown in FIGS. 6 and 7, the convexity or concave rib 101 having regularity and objectivity is put on the surface of the diaphragm 100 to improve the rigidity and resonance. A technique has been adopted in which the frequency characteristics are flattened.

  Here, the concave rib is a rib protruding from the front side to the back side on the diaphragm surface, and looks like a groove when viewed from the front side. The convex rib is a rib protruding forward from the front surface.

  Conventionally, the shape and length of each rib, the arrangement pattern, etc. have regularity and objectivity.

  As prior arts corresponding to the conventional examples shown in FIGS. 6 and 7, for example, Japanese Patent Laid-Open No. 9-224297 and Special Table 2007-535260 exist.

JP-A-9-224297 Special table 2007-535260

The diaphragm of Patent Document 1 is circular as shown in FIG. 6, and a plurality of ribs having the same shape are regularly formed at predetermined intervals from the inner side toward the outer circumference over the entire circumferential direction of the diaphragm 100. It is arranged.
In the diaphragm disclosed in Patent Document 2, the shape of the diaphragm is a track shape. In this document 2, a large number of ribs are formed radially from the inner circular portion to the outer periphery at predetermined intervals at both ends in the longitudinal direction of the diaphragm, and the rib patterns at both ends are equal.

  FIG. 8 shows frequency characteristics of the track-shaped diaphragm shown in FIG. In the diaphragm shown in FIG. 7, the ribs 101 extend from the inside of the diaphragm 100 toward the outer periphery and are arranged at a predetermined interval. Further, the outer end portions of all the ribs 101 extend to the outer peripheral portion of the diaphragm, and are regularly arranged over the entire circumferential direction of the diaphragm. The rib pattern is line symmetric with respect to the long axis at the center in the length direction of the diaphragm 101. Moreover, it is axisymmetric with respect to the short axis and has objectivity.

  In this track-shaped diaphragm, even if a large number of ribs 101 are formed in order to disperse the resonance modes, peaks and dips occur at high frequencies and the sound pressure also decreases, as shown by part A in FIG. Yes.

  As described above, there is a problem that even if the ribs are regularly and symmetrically formed on the surface of the diaphragm in order to reduce the resonance mode, it is impossible to realize a stable flat frequency characteristic in a high range. .

  The present invention has been proposed in view of the above, and an object of the present invention is for an electroacoustic transducer in which a resonance mode in a diaphragm surface is dispersed and a frequency characteristic is stabilized and flat in a high frequency range. An object is to provide a diaphragm and an electroacoustic transducer using the diaphragm.

The invention according to claim 1 is a diaphragm for an electroacoustic transducer in which a plurality of ribs are formed at intervals from an inner side to an outer periphery of the diaphragm, and the ribs are sequentially arranged along the circumferential direction of the diaphragm. It is characterized in that at least one of the shape, length, arrangement, and interval is made an irregular rib pattern.
According to a second aspect of the present invention, in the electroacoustic transducer diaphragm according to the first aspect, the diaphragm has a track shape, a circular dome portion is formed at a central portion, and a voice coil mounting portion is formed at an outer peripheral portion thereof. And a track-shaped edge portion is formed on the outer periphery thereof, a convex rib is formed in the longitudinal direction of the diaphragm having the track shape, and a concave rib is formed in each of the upper half portion and the lower half portion of the track shape. It is characterized by being formed in plural.
The invention according to claim 3 is an electroacoustic transducer including the electroacoustic transducer diaphragm according to claim 1 or 2.

  In the present invention, in the diaphragm for electroacoustic transducers in which a plurality of ribs are formed from the inside of the diaphragm toward the outer peripheral portion with an interval, the shape and length of each rib formed to disperse the resonance mode In addition, at least one of the arrangement and spacing is different to prevent the resonance mode from being easily applied to the weakly rigid part in the diaphragm, and the sound pressure even if reverse resonance occurs between the edge part and the dome part. Since the cancellation or enhancement of each other is suppressed, a large dip peak can be suppressed in a high range, and a good sound quality can be obtained.

1 is a plan view of a track-shaped diaphragm according to an embodiment of the present invention. The perspective view same as the above is shown. The simulation of the frequency characteristic with respect to the sound pressure of the electroacoustic transducer using a diaphragm same as the above is shown. It is explanatory drawing of the simulation of the resonance mode of the diaphragm of the comparative example with respect to this invention. It is explanatory drawing of the simulation of the resonance mode of this invention product. The top view of the conventional circular diaphragm is shown. The top view of the conventional diaphragm of a track shape is shown. The simulation of the frequency characteristic with respect to the sound pressure of the electroacoustic transducer using the conventional diaphragm of a track shape is shown.

  The present invention will be described below with reference to the drawings.

  FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is a perspective view thereof. In this example, a diaphragm having a track shape is shown as an example.

  As apparent from FIG. 2, the vibration surface of the diaphragm 1 has a circular dome portion 1a and a track-shaped edge portion 1b formed on the outer periphery thereof. The edge portion 1b is an outer periphery of the dome portion 1a. From the voice coil mounting portion 2 toward the outer periphery fixing portion, the sound is radiated in a direction of acoustic radiation, and the side cross section has a substantially cone shape. The voice coil mounting portion 2 is closed without a hole, and a dome portion 1a is formed. An outer periphery fixing portion 3 is provided on the outer periphery of the edge portion 1b.

  In this embodiment, on the diaphragm surface, a plurality of convex ribs projecting forward when viewed from the front surface and a plurality of concave ribs projecting toward the rear surface and appearing as recessed grooves when viewed from the front surface are formed. By making at least one of the mutual shape, length, arrangement, and interval different from each other, the rib pattern is made partially non-principle to disperse the resonance modes in the diaphragm surface and to stabilize the frequency characteristics. It is characterized by having been made.

  Here, “no principle” is a concept opposite to the regular rib pattern, and means that at least one of the rib shape, length, position, and interval is made different. And as a form of a rib, the convex rib which protrudes ahead, the protrusion which protrudes in the back side, and the concave rib dented in the back side when it sees from the front surface, or what mixed them may be sufficient. In the case of a mixture of convex ribs and concave ribs, in the present invention, the number of them is made different so that the areas of the concaves and convexes are not equalized and the occurrence of a large peak dip is suppressed.

  In FIG. 1, for convenience of explanation, the center of a circular voice coil mounting portion 2 formed at the center of a track-shaped diaphragm is set to zero. Further, the long axis passing through the center 0 extends along the length direction in the major axis direction of the track shape, XX ′, the minor axis extending along the length direction in the minor axis direction, and the minor axis passing through the center 0 is defined as YY. 'And.

  Further, an XY fan-shaped area centered at the center 0 is a first area, a YX 'area is a second area, an X'-Y' area is a third area, and Y'-X. This area is the fourth area.

  In this track-shaped diaphragm 1, an up-roll-shaped convex on the XX ′ line, on both sides of the voice coil mounting portion 2, and having a substantially inverted U shape projecting forward in the major axis direction. One rib 4, 4 ′ is formed.

  Further, in the minor axis direction on the Y-Y 'line, a long and narrow lens shape is formed, protruding toward the back surface, and recessed concave ribs 5 and 5' are formed as viewed from the front surface. The shape of the concave ribs 5 and 5 'is smaller than that of the convex ribs 4 and 4'.

  In the track-shaped diaphragm 1, the distance from the outer periphery of the circular voice coil mounting portion 2 to the outer periphery of the diaphragm 1 is long in the long axis direction of the X-X ′ line. Therefore, since this portion has low rigidity and a resonance mode is likely to occur, the width of the convex rib 4 is made larger than other ribs described later, and the rigidity of the diaphragm 1 in the long axis direction is increased.

  The inner ends of the convex ribs 4, 4 ′ extend linearly from the outer periphery of the voice coil mounting portion 2 that forms a circle toward the outer periphery of the diaphragm 1. However, the outer ends of the convex ribs 4, 4 ′ are not in contact with the outer peripheral portion of the diaphragm 1, and are located on the inner side away from the outer peripheral portion.

  The width of the convex rib 4 is wide, the inner end is formed in a substantially arc shape, and the outer end is sharper than the inner end.

  Further, the top portions 4a and 4a 'of the convex ribs 4 and 4' are curved with R.

In the state shown in FIG. 1, one convex rib 4 on the long axis on the upper left side on the left side protrudes toward the back side through the convex rib 4 and the interval l ₁ at the upper position in the clockwise direction, A first concave rib 6 having a concave shape when viewed from the front is formed. The inner end of the first concave rib 6 is pointed, and the outer end has a small sharpness compared to the inner end, and the overall shape is formed into an elongated and substantially streamlined shape. The inner end portion of the concave rib 6 is tapered, gradually becomes wider from the inner end portion toward the outer end portion, and the outer end is tapered again, but the width of the outer end portion is the inner end portion. It is slightly wider than the width. The outer end of the concave rib 6 is in contact with the outer peripheral portion of the diaphragm 1. The inner end of the concave rib 6 is located at a substantially central portion of the convex rib 4 located on the lower side, and is not in contact with the voice coil mounting portion 2.

  In the state shown in the drawing, second concave ribs 7 that are longer than the concave ribs 6 and are substantially streamlined are formed at intervals above the first concave ribs 6 in the clockwise direction. The inner end of the second concave rib 7 is in contact with the outer periphery of the voice coil mounting portion 2, and the outer end extends linearly toward the outer periphery of the diaphragm 1, but the outer end is on the outer periphery of the diaphragm 1. It is located slightly inside without touching.

  A first concave rib 8 having a long lens shape when viewed from the front surface is shorter than the first and second concave ribs 6 and 7 with a space above the second concave rib 7 in the clockwise direction. Is formed. The outer and inner ends of the first concave rib 8 are pointed. The outer end is in contact with the outer periphery of the diaphragm 1. The inner end extends toward the voice coil attachment portion 2 side, but does not contact the voice coil attachment portion 2, and there is a slight distance between the inner end and the outer periphery of the voice coil attachment portion 2.

  A second concave rib 9 having a substantially lens shape is formed in the clockwise direction and lateral direction of the first substantially lens-shaped concave rib 8 with a space therebetween. The second concave rib 9 is longer than the first concave rib 8 and has an elongated shape. The outer end is in contact with the outer periphery of the diaphragm 1. Although the inner end extends toward the voice coil mounting portion 2, the inner end is closer to the outer periphery of the voice coil mounting portion 2 than the first concave rib 8, but there is a slight gap.

  A third concave rib 10 having a substantially lens shape is formed in the clockwise direction of the second concave rib 9 with an interval therebetween. The third concave rib 10 is shorter in length than the second concave rib 9 having the above lens shape. The outer end is in contact with the outer periphery of the diaphragm 1. The inner end extends toward the voice coil mounting portion 2, but there is a slight gap between the inner end and the outer periphery of the voice coil mounting portion 2.

  In the clockwise direction of the third concave rib 10, elongated lens-shaped concave ribs 5 that are slightly shorter than the concave ribs 10 are formed at intervals. The concave rib 5 is located on the minor axis of the Y-Y ′ line. The outer end is in contact with the outer periphery of the diaphragm 1. The inner end extends toward the voice coil mounting portion 2, but there is a slight gap between the inner end and the outer periphery of the voice coil mounting portion 2.

  In the first region, the distance between the convex rib 4 and the first concave rib 6 that is substantially streamlined, the distance between the first concave rib 6 and the second concave rib 7, and the second concave rib 7 The distance from the first concave rib 8 that is substantially in the shape of a lens, the distance from the second concave rib 9 that is substantially in the shape of a lens similar to the first concave rib 8, and the same lens shape as the second concave rib 9. The interval between the third concave rib 10 and the interval between the third concave rib 10 and the concave rib 5 located on the YY ′ line are different as apparent from the illustrated embodiment.

  Further, the distance between the inner end of each rib and the outer periphery of the voice coil mounting portion 2, that is, the distance from the center 0 is different. The rib pattern in the first region is in principle.

  In the second region, the concave ribs 10 are formed at intervals in the clockwise direction of the concave ribs 5 on the Y-Y ′ line. The shape of the concave rib 10 is the same as the above-described third concave rib 10 in the first region formed adjacent to the counterclockwise direction (left side in the illustrated state) with respect to the concave rib 5. .

  Concave ribs 9 are formed at intervals in the clockwise direction of the concave ribs 10 in the second region. The shape of the concave rib 9 is the same as that of the second concave rib 9 in the first region.

  A concave lens 11 having a substantially lens shape is formed in the clockwise direction of the concave rib 9 with a gap therebetween. The outer end of the concave rib 11 is in contact with the outer periphery of the diaphragm 1. The inner end is separated from the voice coil mounting outer peripheral portion 2. The concave rib 11 is different in shape from the first concave rib 8 in the first region. The interval between the concave rib 11 and the concave rib 9 in the second region is such that the second concave rib 9 having a substantially lens shape in the first region and the first concave on the counterclockwise side adjacent to the second concave rib 9 are formed. The distance from the rib 8 is wider.

  In the clockwise direction of the concave ribs 11 in the second region, concave ribs 7 that are substantially streamlined are formed at intervals. The shape of the concave rib 7 in the second region is the same as that of the second concave rib 7 which is substantially streamlined in the first region, but the distance from the other ribs located on both sides is different.

  In the clockwise direction of the concave ribs 7 in the second region, concave ribs 6 that are substantially streamlined are formed at intervals. The shape of the concave rib 6 is substantially the same as that of the first concave rib 6 which is substantially streamlined in the first region, but the distance between the other ribs located on both sides is different.

It is formed 'other convex ribs 4 on the line' X-X through the interval l ₂ in the clockwise direction of the concave rib 6 of the second region. This interval l ₂ is shorter than the interval l ₁ between the one convex rib 4 and the concave rib 6 on the first region side. The ribs in the second region are also in principle.

  Next, the rib in the third region will be described.

It is formed concave rib 6 through the spacing l ₁ to the other clockwise convex ribs 4 on the long axis. The shape of the concave rib 6 is substantially the same as that of the first concave rib 6 in the first region. Further, the distance from the other convex rib 4 ′ is substantially the same as the distance l ₁ between the first concave rib 6 and the first convex rib 4 in the first region.

  In the clockwise direction of the concave rib 6 in the third region, a concave rib 7, a concave rib 8, a concave rib 9, a concave rib 10, and a concave rib 5 'on the Y-Y' line are formed, respectively. The shape of each of these ribs 6 to 10 is the same as the first and second concave ribs 6 and 7 that are substantially streamlined in the first region, and the first to third concave ribs 8 to 10 that are substantially lens-shaped. However, the ribs in the third region are not in principle.

  Next, the rib in the fourth region will be described.

  YY ′ between the concave rib 5 ′ on the YY ′ line at the boundary between the third and fourth regions and the convex rib 4 on the XX ′ line at the boundary between the fourth and first regions. Concave ribs 10, concave ribs 9, concave ribs 11, concave ribs 7, and concave ribs 6 are formed in order from the concave rib 5 'on the line.

  In the second region, the shape of these ribs is that the concave rib 10, the concave rib 9, the concave rib 11, the concave rib 7, the concave rib 10, which are sequentially formed from one concave rib 5 on the YY 'line through a space. Although it is almost the same as the rib 6, the ribs in the fourth region are not in principle.

  As described above, a pair of convex ribs 4, 4 ′ are formed in the major axis direction, and a plurality of concave ribs are provided at intervals on the upper half and lower half of the track-shaped diaphragm 1 with respect to the major axis. These ribs are formed radially between the outer periphery of the voice coil mounting portion 2 and the outer periphery of the diaphragm 1.

  The shape and arrangement of the ribs described above are not line symmetric with respect to the X-X ′ line. The left half and the right half of the Y-Y ′ line are not line symmetrical. In the present invention, the ribs are arranged adjacent to each other in the circumferential direction, and the ribs have different shapes, lengths, intervals, and the like. In the present invention, when the diaphragm is equally divided into two or more regions, the shape, length, arrangement, and interval of adjacent ribs are different and irregularly formed in at least one region. And the shape, length, arrangement, interval, and the like of each rib in each of the first to fourth regions in the circumferential direction are all different and completely non-principle.

  A voice coil (not shown) is attached to the back surface of the voice coil mounting portion 2 of the diaphragm 1 and is disposed in a magnetic gap of a magnetic circuit (not shown) having an appropriate configuration, and the diaphragm 1 is tracked. A track-type electroacoustic transducer was fabricated by incorporating it into a shaped frame (not shown).

  FIG. 3 shows a simulation of frequency characteristics with respect to sound pressure of the electroacoustic transducer.

  According to the present invention, as indicated by B surrounded by a circle, the resonance mode is suppressed in the high frequency range, the sound pressure is improved, the occurrence of peak dip is suppressed, a good frequency characteristic is obtained, and the sound quality Improved.

  According to the present invention, the resonance mode is suppressed. As a comparative example for verifying the resonance mode, the resonance of the electroacoustic transducer using the diaphragm made of the rib 101 having regularity and symmetry shown in FIG. A simulation of mode measurement is shown.

  FIG. 4 shows a simulation of a resonance mode at a specific frequency of the electroacoustic transducer of the comparative example.

  In this diaphragm, a strong resonance mode in which the red portion a is concentrated on the voice coil mounting portion 2 at both ends in the length direction occurs, a yellow b portion around the periphery, a green c portion around the periphery, The resonance mode of the sky blue d portion was generated around it. The other minor axis direction and the outer peripheral part generally exhibited blue e. The color corresponds to the absolute value of the deflection amount of the diaphragm, blue e → sky blue d → green c → yellow b → red a indicates the degree of vibration, blue e has less resonance, and red a vibrates well. Indicates that In this diaphragm, the red a portions are concentrated on both ends of the longer diameter side compared to the shorter diameter side and at the central portion on the voice coil mounting portion 2 side, and the resonance mode is large.

  Therefore, even if the ribs 101 are regularly formed in the circumferential direction at a predetermined interval in the circumferential direction in order to reduce the resonance mode, resonance occurs and a stable flat frequency characteristic is realized on the high frequency side. You can't do that.

  FIG. 5 shows a simulation of a resonance mode at the same specific frequency of the electroacoustic transducer using the diaphragm 1 according to the present invention in which the rib pattern is in principle.

  According to the present invention, the resonance modes are dispersed, and the strong resonance mode of red a is reduced. In addition, the areas of yellow b, green c, and sky blue d around the area were reduced. In the figure, a 'is orange, and the resonance mode is lower than red a.

  As in the conventional product, when the ribs formed on the diaphragm are in a regular pattern, concentrated resonance modes appear. The reason for this is that with a diaphragm having a regular pattern, it is easy for the resonance mode to ride on the less rigid part of the diaphragm, and in some cases, reverse resonance occurs between the edge and dome, and so on. Canceling or strengthening each other, as shown by A in FIG. 8, a large dip peak is generated in the frequency characteristic.

  On the other hand, in the product of the present invention, at least one of the shape, length, arrangement, spacing, and the like of at least adjacent ribs is made different to make the rib pattern irregular, and a resonance mode is placed in the diaphragm. When the edge portion 1b and the dome portion 1a are reversely resonated, the sound pressures are prevented from canceling or strengthening, and the occurrence of a large peak dip in the high range is suppressed.

  Therefore, the favorable frequency characteristic shown in FIG. 3 could be obtained.

  1 and 2, the number, shape, length, arrangement, spacing, and the direction in which the ribs extend from the inner side of the diaphragm toward the outer peripheral portion, etc. The embodiment considered to be optimum of the present invention is illustrated and is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

  In the embodiment shown in FIGS. 1 and 2, the convex ribs 4 and 4 'and the concave ribs 5 to 11 are mixed as ribs, but either rib may be used instead.

  Moreover, although the track-shaped diaphragm has been described in the above embodiment, the present invention can also be applied to a circular diaphragm.

DESCRIPTION OF SYMBOLS 1 Diaphragm 1a Dome part 1b Edge part 2 Voice coil attachment part 3 Outer periphery fixing | fixed part 4, 4 'Convex rib 5, 5' Concave rib 6 Substantially streamlined concave rib 7 Substantially streamlined concave rib 8 Substantially lens-shaped concave Rib 9 Nearly lens-shaped concave rib 10 Nearly lens-shaped concave rib 11 Nearly lens-shaped concave rib l ₁ , l ₂ Distance 0 Center XX ′ Long axis YY ′ Short axis

Claims (3)

In the diaphragm for an electroacoustic transducer in which a plurality of ribs are formed at intervals from the inside of the diaphragm toward the outer periphery,
A diaphragm for an electroacoustic transducer, characterized in that an irregular rib pattern is formed by varying at least one of the shape, length, arrangement, and interval of the ribs sequentially arranged along the circumferential direction of the diaphragm.   The diaphragm for an electroacoustic transducer according to claim 1, wherein the diaphragm has a track shape, a circular dome portion is formed at a central portion, a voice coil attachment portion is formed at an outer peripheral portion thereof, and an outer peripheral portion thereof is A track-shaped edge portion is formed, a convex rib is formed in the major axis direction of the track-shaped diaphragm, and a plurality of concave ribs are formed in each of the upper half portion and the lower half portion of the track shape. A diaphragm for an electroacoustic transducer.   An electroacoustic transducer comprising the diaphragm for an electroacoustic transducer according to claim 1.

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