JP3984345B2 - Electroacoustic transducer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electroacoustic transducer such as a speaker or a microphone.
[0002]
[Prior art]
The speaker has a diaphragm, and the outer periphery of the diaphragm is supported through an edge. The edge is also required to have various characteristics such as shape and material in order to obtain desired acoustic characteristics.
There are various types of speakers. Of these, FIG. 9 is a longitudinal sectional view of a conventional speaker provided with an up-roll type edge, and FIG. It is explanatory drawing which shows the difference in the air quantity which an up-roll type edge part excludes when it moves to the front-back direction.
[0003]
The speaker shown in FIG. 9 includes a yoke 2 constituting the bottom 1 of the speaker, a magnet 3 attached to the upper surface of the yoke 2, a pole piece 4 attached to the upper surface of the magnet 3, and the yoke 2 The voice coil 5 and the boil coil bobbin 6 held in the magnetic gap between the pole pieces 4, the dome-shaped diaphragm 7 fixed to the tip of the boil coil bobbin 6, and the up provided on the outer periphery of the diaphragm 7 A roll-type edge portion 8 and a frame 9 for holding the respective members are provided.
[0004]
[Problems to be solved by the invention]
In the speaker, the outer peripheral portion of the diaphragm 7 is supported by the edge portion 8 so as to vibrate. The linearity with respect to the input of the support portion of the diaphragm 7 becomes asymmetrical in the vertical direction as the amplitude increases, which causes generation of harmonic distortion. For example, in the case of an up-roll type edge portion, as shown in FIG. 10, even when the diaphragm 7 moves forward and backward by the same displacement amount, the air amounts A1 and A2 excluded by the edge portion 8 are different. It becomes. In addition, the difference increases as the displacement amount of the diaphragm 7 increases.
[0005]
The sound pressure of the speaker is proportional to the sum of the air amounts excluded by the diaphragm 7 and the edge portion 8. For this reason, as the amplitude of the diaphragm 7 increases, the sound pressure difference between before and after increases, and as a result, there is a problem that harmonic distortion increases.
[0006]
The present invention has been made in view of the above circumstances, and its object is to reduce the generation of harmonic distortion, to make it difficult to change the stiffness of the edge portion, and to increase the stroke of the diaphragm. The object is to provide an electroacoustic transducer with an edge that can be taken.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in an electroacoustic transducer having an up roll 16 and a down roll 17, the up / down roll connecting planes 18 are adjacent to each other with a certain range of angles α. It is the structure formed so that it might consist of reverse direction alternately .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0009]
1 to 5 show a first embodiment of the present invention. FIG. 1 is a plan view of a diaphragm and an edge portion supporting the diaphragm, FIG. 2 is a cross-sectional view taken along line AA 'of FIG. 1 is a sectional view taken along the line BB 'in FIG. 1, and FIG. 4 is an enlarged explanatory view showing the planar shape and sectional shape of the roll adjacent to the circumferential direction of the edge portion. It is drawn as ~ H-H '. FIG. 5 is a cross-sectional view of a speaker in which a diaphragm is supported by the edge portion.
[0010]
In the first embodiment of the present invention shown in these drawings, as shown in FIGS. 1 and 2, the edge portion 10 that supports the diaphragm 7 is substantially along the tangential direction 12 with respect to the inner periphery 11 of the edge portion 10. A plurality of rolls 15 are formed at equal intervals in the circumferential direction 13 of the edge portion.
[0011]
As shown in FIGS. 3, 4, etc., the roll 15 is formed by combining the roll portions of the up roll 16 and the down roll 17 in a vertically symmetrical manner. And the roll 15 adjacent to the circumferential direction 13 of the edge part 10 is formed by arrange | positioning the up roll 16 and the down roll 17 alternately. Therefore, in this embodiment, the up roll 16 and the down roll 17 of each roll 15 are connected by a plane 18 having an angle α≈70 ° formed by the vibration surface 14 of the edge portion 10. In the present invention, the plane 18 that contacts the upper and lower roll portions is formed in a substantially tangential direction 12 of the curve 11 that forms the inner periphery of the roll 15.
[0012]
The angle α corresponds to the angle between the vibration surface 14 and the tangent line a drawn to the inner peripheral portion of the roll 15 as shown in FIG. As is clear from FIGS. 2 and 3, the planes 18 that connect the up roll 16 and the down roll 17 are adjacent to each other, and are alternately formed in opposite directions at a certain angle α.
[0013]
The diaphragm 7 is supported by the frame 9 as shown in FIG. 5 through the edge portion 10 configured as described above. In FIG. 5, the same members as those in FIG. 9 showing the prior art are denoted by the same reference numerals.
[0014]
According to the first embodiment, since the up roll 16 and the down roll 17 of the roll 15 adjacent to the circumferential direction 13 of the edge portion 10 are formed alternately, the adjacent to the circumferential direction 13 of the edge portion 10. The sum of the amount of air excluded from the matching rolls 15 is the same when the edge portion 10 moves forward and backward, and as a result, the amount of air excluded from the edge portion 10 also increases forward and backward. It is equivalent to the case where it moves. As a result, the amount of air excluded by the diaphragm 7 and the edge portion 10 is the same when moving forward and backward, and therefore, the generation of harmonic distortion can be reduced.
[0015]
Compared to an example in which conventional vertically symmetrical rolls are simply arranged alternately in the circumferential direction of the edge portion, in this first embodiment, the portion (plane 18) that contacts the up roll 16 and the down roll 17 is the roll 15. Is formed substantially in the tangential direction of the tangent line a of the curve 11 forming the inner circumference of the edge portion 10, so that the curvature of the roll shape is not changed and the compliance of the edge portion 10 is hardly affected. It is possible to make it difficult for partial stiffness changes to occur.
[0016]
Further, unlike the conventional so-called tangential edge, since the basis of the edge portion 10 is a roll shape, there is an advantage that a large stroke of the edge portion 10 can be taken.
[0017]
6 to 8 show a second embodiment of the present invention. FIG. 6 is a plan view of a diaphragm and an edge portion supporting the diaphragm. FIG. 7 is a cross-sectional view taken along the line II 'in FIG. 8 is a cross-sectional view taken along the line JJ ′ of FIG.
[0018]
In the second embodiment shown in these drawings, as can be seen from FIGS. 7 and 8, the up roll 16 and the down roll 17 of each roll 15 formed on the edge portion 10 are connected to the vibration surface 14 of the edge portion 10. Are connected by a plane 18 having an angle α≈90 °.
[0019]
That is, the angle α formed between the tangent to the inner peripheral portion of the roll and the vibration surface 14 varies depending on the radius R and the height h of the roll 15, and when R = h, the angle α is 90 °.
[0020]
If h is smaller than R, it becomes 70 ° or less as in the above-described embodiment. The range of the angle α is about 90 ° to 45 °.
[0021]
Even in the second embodiment, since the curvature of the roll shape is not changed and the compliance of the edge portion 10 is hardly affected, it is possible to make it difficult to cause a partial stiffness change of the edge portion 10. Become.
[0022]
The other configuration of the second embodiment is the same as that of the first embodiment, and the operation is also the same.
[0023]
【The invention's effect】
As described above, according to the present invention, in the electroacoustic transducer having the up-roll 16 and the down-roll 17 at the edge, the planes 18 for connecting the up-down rolls are adjacent to each other with a certain range of angles α. in is formed so as to form in opposite directions, when the sum of the amount of air to be excluded from the roll 15 portion adjacent to the circumferential direction 13 of the edge portion 10, the edge portion 10 is moved forward and backward with the As a result, the amount of air excluded from the edge portion 10 is the same for the front and the rear, so that the amount of air excluded by the diaphragm 7 and the edge portion 10 is the same when moving forward and backward. Therefore, there is an effect that the generation of harmonic distortion can be reduced.
[0024]
Furthermore, according to the present invention, the up-roll 16 and the down-roll 17 forming the roll 15 are formed by a plane 18 formed by an angle α formed between a tangent drawn to the inner peripheral portion of the roll shape and the vibration surface 14. Since they are connected, the roll shape curvature is not changed, and the compliance of the edge portion 10 is hardly affected. Therefore, there is an effect that a partial stiffness change of the edge portion 10 can hardly be caused.
[0025]
In addition, in the present invention, since the basis of the edge portion 10 is a roll shape, there is an advantage that the stroke of the edge portion 10 can be made larger than that of the conventional tangential edge.
[Brief description of the drawings]
FIG. 1 is a plan view of a diaphragm and an edge portion that supports the diaphragm according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG.
FIG. 3 is a cross-sectional view taken along the line BB ′ of FIG.
FIG. 4 is an enlarged explanatory view showing a planar shape and a cross-sectional shape of rolls adjacent to each other in the circumferential direction of the edge portion in the first embodiment.
FIG. 5 is a cross-sectional view of the speaker in the first embodiment.
FIG. 6 is a plan view of a diaphragm and an edge portion that supports the diaphragm according to a second embodiment of the present invention.
7 is a cross-sectional view taken along the line II ′ of FIG.
FIG. 8 is a cross-sectional view taken along the line JJ ′ of FIG.
FIG. 9 is a longitudinal sectional view of a conventional speaker provided with an up-roll type edge portion.
FIG. 10 is an explanatory diagram showing a difference in air amount excluded by an up-roll type edge when the diaphragm moves in the front-rear direction in the conventional speaker.
[Explanation of symbols]
7 Diaphragm 10 Edge part 11 Inner circumference 12 of edge part Tangent direction 13 with respect to inner circumference of edge part Circumferential direction 14 of edge part Vibration surface 15 of edge part 16 Roll 16 Up roll 17 Down roll 18 Up roll and down roll are connected The angle between the plane α vibrating surface and the plane for connecting the up / down rolls

Claims (1)

In an electroacoustic transducer having an up roll 16 and a down roll 17 at the edge,
2. The electroacoustic transducer according to claim 1, wherein the up / down roll connecting planes 18 are formed adjacent to each other and alternately in opposite directions with a certain range of angles α .

Images