JPH0879885A - Speaker - Google Patents

Abstract

PURPOSE: To reduce second harmonic distortion in the sound frequency characteristic due to an amplitude of a free edge of the speaker used for various sound equipments and to improve the linearity of the amplitude. CONSTITUTION: A roll part in which a cross section of a free edge 11 is formed to two or plural projections is provided and projection rolls 12, 14 arranged at an inner circumferential part are selected larger than rolls 13, 15 at an outer circumferential part and decreased toward the outer circumferential part and the shape of the rolls of a larger diameter and a shorter diameter differs from each other, then deformation of the free edge 11 displaced in forward/backward directions is avoided, the linearity of a support force is improved and amplitude bent points P1, P2 are set nearly at the same position, them the amplitude margin is improved. Furthermore, the symmetry of forward/backward vibration is improved, then the asymmetry of the support force resulting from the asymmetry of amplitude is considerably improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker used in various audio equipment.

[0002]

2. Description of the Related Art In recent years, since the digital signal processing technology has advanced dramatically and the quality of electric signals supplied to a speaker has been greatly improved, it is strongly desired to develop a speaker capable of reproducing high sound quality correspondingly. Is coming.

A conventional speaker will be described below with reference to the drawings. FIG. 4 shows a structural cross section of a conventional speaker. In FIG. 4, 1 is a bottom plate provided with a center pole, 2 is a ring-shaped magnet fixed to the bottom plate 1, 3 is a top plate fixed to the upper surface of the magnet 2, and 4 is an inner circumference of the top plate 3 and the bottom plate. A voice coil held in a magnetic gap formed by the outer peripheral surface of the center pole included in 1.
5 is a bobbin of the voice coil 4, 6 is an elliptical diaphragm fixed to the tip of the bobbin 5 of the voice coil 4, 7 is a damper fixed to the outer periphery of the bobbin 5 of the voice coil 4, and 8 is an oval diaphragm. 6 is a free edge provided on the outer peripheral portion, 9 is a frame that fixes the outer periphery of the damper 7 and the free edge 8 and is joined to the upper surface of the top plate 3, and 10 is affixed to the central upper surface of the oval diaphragm 6. It is a dust cap.

The operation of the speaker configured as described above will be described below. First, when an electric signal is applied to the voice coil 4, a driving force is generated in the voice coil 4. This driving force is transmitted to the bobbin 5 of the voice coil 4 to vibrate the elliptical diaphragm 6 fixed to the tip of the bobbin 5 and emit a sound corresponding to the vibration.

[0005]

However, in the above-mentioned conventional structure, the oval diaphragm 6 is supported by the damper 7 and the free edge 8 fixed to the outer peripheral portion of the voice coil 4, and the supporting force of these supports is reduced. The linearity becomes a problem when reproducing in the low frequency range where the amplitude becomes large, and becomes a cause of harmonic distortion.

In particular, in the case of an elliptical small-diameter woofer or the like, in order to obtain the same level of sound pressure at the same frequency in the bass range, it is necessary to make the amplitude larger than that of a circular large-diameter woofer. However, one of the problems at the time of large amplitude is that the edge margin is small or the edge is bent due to the small amplitude margin of the edge, causing the edge to break and reducing the input resistance. Had.

Therefore, conventionally, in order to increase the amplitude margin of the free edge 8, the free edge 8 is enlarged to widen the roll width. However, with this method, the oval diaphragm 6
However, there is a problem that the area becomes smaller, the sound pressure decreases, and edge resonance easily occurs.

Further, the vibration mode of the free edge 8 is as shown in FIG. In the figure, A is a neutral state before an electric signal is applied to the voice coil 4, B is a state oscillating forward from the neutral point, and C is a state oscillating rearward from the neutral point. In each vibration state, assuming that the position P where the elliptical diaphragm 6 moves back and forth with respect to the neutral point is the same, and the reference amplitude bending point at the neutral point is P0, the elliptical vibration is generated. As shown in FIG. 5, the amplitude bending point of the free edge 8 vibrating with the plate 6 is the amplitude bending point when moving from the position A to the state B, and the amplitude when moving from the position A to the state C. When the bending point is P2, the way of deformation when the edge oscillates forward and backward is different, and therefore the point position is different.

That is, from the certain amplitude amount (+ ξ) at the B position, the amplitude bending point becomes the P1 position with the edge being stretched, and at the C position, the certain amplitude amount (-).
From ξ), the amplitude bending point is P when the edge is bent.
Since the position becomes position 2, the distortion component of the sound pressure characteristic of the speaker increases, and the amplitude bending point of the free edge 8 becomes asymmetrical due to the front-back vibration particularly in the low sound range of 200 Hz or less, and the second harmonic distortion increases. It had a problem of generating an abnormal sound.

The present invention solves the above-mentioned problems of the prior art by improving the amplitude margin of the free edge, which is the support of the elliptical diaphragm, without deteriorating the linearity of its support force. It is an object of the present invention to provide a speaker capable of significantly reducing harmonic distortion due to asymmetry in amplitude.

[0011]

In order to achieve this object, a speaker of the present invention has a roll portion having a plurality of concavo-convex portions with two or more free edges, of which the inner peripheral portion is arranged. The shape of the concave or convex roll part is larger than the roll part of the outer peripheral part, becomes smaller toward the outer peripheral part, and the shape of the roll part on the major diameter side and the minor diameter side is different, An elliptical diaphragm is joined to the inner circumference of the edge, and an elliptical frame is joined to the outer circumference of the free edge.

[0012]

With this structure, the deformation when the free edge oscillates forward and backward is eliminated, the linearity of the supporting force is improved, and the amplitude bending point is almost at the same position, so that the amplitude margin is increased. Furthermore, since the symmetry at the time of the front-back amplitude is improved, the asymmetry of the supporting force due to the asymmetry of the amplitude can be significantly improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a plan view of a speaker according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line A-O-B in FIG. In the figure, the same components as those of the conventional example shown in FIG.
The description is omitted.

The free edge 1 is largely different from the conventional example.
The shape is 1. In FIG. 1, reference numeral 12 denotes a convex roll portion having a size larger than that of the inner circumference on the major diameter side and the minor diameter on the same circumference.
Is a concave roll portion having a size larger than that of the outer circumference on the major diameter side having the same short diameter, 14 is a convex roll portion having a size slightly smaller than that of the inner circumference having the major diameter on the minor diameter side, and 15 is the minor diameter It is composed of a concave roll portion having a size slightly smaller than that of the outer circumference on the side having the same major axis. That is, the major axis side concave-convex roll portions 12 and 13 and the minor axis side concave-convex roll portions 14 and 1
Reference numeral 5 is set to have such a dimension that it has an irregular shape.

The operation of the speaker configured as above will be described with reference to FIG. First, when an electric signal is applied to the voice coil 4, the elliptical diaphragm 6 is displaced. At that time, the amplitude of the free edge 11 is displaced forward and backward as described with reference to FIG. Since the way of deformation at the time of doing is different, the position of the amplitude bending point becomes asymmetric, and the free edge 11 is stretched or bent, and even if the elliptical diaphragm 6 is moved linearly, the distortion component increases. Was imitating.

However, as shown in FIGS. 1 and 2, in the present invention, the convex roll portions 12 and 14 arranged on the inner peripheral portion are larger than the concave roll portions 13 and 15 arranged on the outer peripheral portion. Therefore, it plays a role as a support for the elliptical diaphragm 6 without causing deformation at a large amplitude in the low tone range, and further, the convex roll portions 12, 14 at the inner peripheral portion.
The shape of is not a simple size of a single roll but forms a rising straight line part that is the same as the amplitude direction, and the shape of the roll part gradually decreases toward the outer circumference, so that it looks like a vibration damping wave. Confirms the ideal new free edge shape without loss.

Further, since the shape of the concave and convex rolls having the long and short diameters and the convex roll have different shapes, the amplitude margin, which has always been a problem with the elliptical diaphragm, is insufficient. Also, it is possible to disperse the disturbance of the resonance frequency of each roll portion when the bird-wing-shaped divided vibration occurs. Further, it is possible to eliminate unnecessary disturbance of the sound pressure characteristic due to the free edge resonance which is likely to occur in the middle sound range, and to realize a flat sound pressure characteristic. In particular, since there is no amplitude distortion or loss at the time of amplitude, it is possible to significantly reduce the second harmonic distortion.

Incidentally, the convex roll portions 12 and 14 on the major diameter side and the minor diameter side and the concave roll portions 13 and 15 shown in FIG. 1 may be concave roll portions and convex roll portions opposite to those shown in the drawing. It operates in the same manner as described above. Further, the shape of the roll portion of the inner peripheral portion of the present embodiment is formed by the rising straight portion as described above, but the shape of the roll portion of the inner peripheral portion is the same even if it is the same arc even if it is larger than the roll portion of the outer peripheral portion. Shows the action.

FIG. 3 shows sound pressure frequency characteristics 16 and second harmonic distortion characteristics 18 of an elliptical speaker having a diameter of 12 × 8 cm and sound pressure frequency characteristics 17 and second harmonic of a conventional speaker according to this embodiment. The wave distortion characteristics 19 are shown for comparison.

As is apparent from FIG. 3, the speaker according to the present embodiment has a significantly reduced second harmonic distortion characteristic 18 in the low sound range of 200 Hz or less. Further, it can be clearly seen that even in the sound pressure frequency characteristic in the middle frequency range, free edge resonance is eliminated and the sound pressure characteristic is controlled to be flat.

[0021]

As described above, according to the present invention, the free edge has a roll portion having two or more irregularities, and the shape of the concave or convex roll portion disposed on the inner peripheral portion of the roll portion. Is larger than the roll part of the outer peripheral part, becomes smaller toward the outer peripheral part, and because the shape of the roll part on the major diameter side and the minor diameter side is different, deformation when the free edge fluctuates up and down forward and backward , The linearity of the bearing force is improved, the amplitude bending point is almost at the same position, the amplitude margin is increased, and the symmetry at the time of amplitude is improved, and the asymmetry of the amplitude causes the asymmetry of the bearing force. Since it can be greatly improved, the second harmonic distortion is reduced in the low sound range, and it is possible to provide a speaker with low distortion and rich bass reproduction even with a small aperture. Moreover, by making the shapes of the concave and convex roll portions on the long diameter side and the short diameter side different shapes, the insufficient amplitude margin, which has always been a problem with the elliptical diaphragm, and each roll when bird-wing-shaped divided vibration occurs It is possible to disperse the disturbance of the resonance frequency of the part, eliminate the unnecessary disturbance of the sound pressure characteristic due to the free edge resonance that tends to occur in the middle range, and control the characteristic, and reproduce a flat sound pressure characteristic. It makes it possible.

[Brief description of drawings]

FIG. 1 is a plan view of a speaker according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line A-O-B in FIG.

FIG. 3 is a characteristic diagram comparing the sound pressure frequency characteristics / second harmonic distortion characteristics of the speaker of the present invention with the same characteristics of a conventional speaker.

FIG. 4 is a structural sectional view of a conventional speaker.

5 is a cross-sectional view of essential parts showing a vibration state of a free edge of the speaker shown in FIG.

[Explanation of symbols]

 4 Voice coil 6 Elliptical diaphragm 11 Free edge 12 Convex roll part on the major diameter side 13 Concave roll part on the major diameter side 14 Convex roll part on the minor diameter side 15 Concave roll part on the minor diameter side

Claims (1)

[Claims] 1. A roll portion having two or more concave and convex shapes is provided between an elliptical diaphragm and an outer peripheral frame portion that joins the diaphragm, and a concave portion disposed on the inner peripheral portion of the roll portion. Alternatively, a speaker having a free edge in which the convex roll shape is larger than the outer peripheral roll portion, becomes smaller toward the outer peripheral portion, and the roll portion shapes on the major diameter side and the minor diameter side are different shapes.