JPH05236593A - Speaker - Google Patents

Abstract

PURPOSE:To reduce harmonic distortion in a sound pressure frequency characteristic of radiation from an edge. CONSTITUTION:An edge 11 is provided to an outer circumferential part of a cone diaphragm 7. The edge 11 connects projection rolls 12,13, recessed rolls 14, 15, connected with air shields 16,17,18,19 made of a cylindrical foamed body. The sum of the air quantity evacuated by the projected and recessed rolls is made constant with respect to the upper and lower amplitude of the edge to eliminate the asymmetry of air evacuating quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker edge.

[0002]

2. Description of the Related Art In recent years, since the digital signal processing technology has made great progress and the quality of electric signals supplied to a speaker has been greatly improved, a speaker capable of reproducing high-quality sound has been strongly desired. There is. The conventional speaker will be described below with reference to the drawings.

FIG. 5 is a structural cross-sectional view of a conventional speaker. 1 is a plate, 2 is a yoke integrally formed with the plate 1, 3 is a magnet fixed to the plate 1, and 4 is an upper surface of the magnet 3. The fixed center pole, 5 is a voice coil held in a magnetic gap formed by the outer circumference of the center pole 4 and the inner circumferential surface of the yoke 2, 6 is a bobbin of the voice coil 5, and 7 is fixed to the tip of the voice coil bobbin 6. Cone-shaped diaphragm, 8 is a damper fixed to the outer peripheral portion of the voice coil bobbin 6, 9 is an edge provided on the outer peripheral portion of the cone-shaped diaphragm 7, and 10 is a plate 1 and a yoke fixed to the outer periphery of the damper 8 and the edge 9. 2, a frame that holds a magnetic circuit composed of a magnet 3 and a center pole 4.

In the above structure, when an electric signal is applied to the voice coil 5, the driving force generated in the voice coil 5 is transmitted to the voice coil bobbin 6 and vibrates the cone-shaped diaphragm 7 fixed to the tip thereof.

[0005]

In such a conventional speaker, the cone-shaped diaphragm 7 is supported by the damper 8 and the edge 9 fixed to the outer peripheral portion of the voice coil bobbin 6,
The linearity of the supporting force of these supports poses a problem especially during reproduction in the low frequency range where the amplitude becomes large, and causes harmonic distortion. Various shapes have been devised for the damper 8 and the edge 9 in order to improve the linearity of the support. As a result, what is most commonly used as the edge 9 at present is a roll shape as shown in (FIG. 5), and by combining with the corrugated damper 8, the linearity of the supporting force of the support is obtained. Has been greatly improved.

However, the vibration state of the roll-shaped edge 9 is shown in FIG. 6 (FIG. 6). In the figure, A is a neutral state before an electric signal is applied to the voice coil 5, 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, the cone-shaped diaphragm 7 has the same amplitude value ξ moving back and forth with respect to the neutral point. That is, the edge 9 does not include a non-linear component in the operation of the cone-shaped diaphragm as the support. However, the amount of air removed by the edge 9 that oscillates together with the cone-shaped diaphragm 7 is (from FIG. 6),
If the air amount when moving to the state of U is U1 and the air amount when moving from the position of A to the state of C is U2, these values will be different due to the deformation of the roll shape of the edge. .. The sound pressure characteristic as a speaker is proportional to the sum of the cone-shaped diaphragm 7 and the amount of air removed by the edge 9, but the sound pressure radiated from the edge 9 depends on the amount of air removed as described above. The sound pressure characteristic of the speaker always included a distortion component because the sound pressure characteristic of the speaker always included a distortion component because it varied depending on the movement of.

(FIG. 7) is 14 cm using a roll edge.
It shows the sound pressure frequency characteristics of the speaker of the caliber. Here, the driving force generated in the voice coil 5 does not include a non-linear component. A short voice coil system with a small winding width is used. Since the amount of air removed at the edge is asymmetrical due to front-back vibration, second harmonic distortion occurs in the low frequency range below 100 Hz.

The present invention solves the above-mentioned problems by significantly reducing the harmonic distortion due to the asymmetry of air without deteriorating the linearity of the supporting force of the edge which is the support of the diaphragm. The purpose is to realize a high-quality speaker.

[0009]

In order to achieve the above object, the present invention divides the edge length direction into a plurality of pieces, and divides the adjacent pieces into a symmetrical structure to divide the adjacent pieces. It is configured such that an air shielding portion is connected to the one piece, a diaphragm is joined to the inner or outer circumference of the edge, and a frame is joined to the outer or inner circumference of the edge.

[0010]

According to the present invention, since the edge is divided into a plurality of pieces and the adjacent divided pieces have a symmetrical structure according to the above structure, the amplitude of the vibration plate and the amount of air removed from one piece of the edge and The amount of air removed from one of the two is symmetrical with respect to the neutral point where no electric signal is applied, and the combined amount of removed air becomes equal to the vertical amplitude.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (a) is a structural sectional view of the speaker in the first embodiment of the present invention, and FIG. 1 (b) is a plan view. In the figure, the same components as those of the conventional example shown in (FIG. 5) are denoted by the same reference numerals. The structure of the edge 11 is largely different from the conventional example.
Is a convex roll, 14, 15 is a concave roll, 16, 1
Reference numerals 7, 18, and 19 are air shielding parts made of a cylindrical foam.

FIG. 2 shows a detailed view of the appearance of the edge 11. The convex roll 12 and the concave roll 15 have a vertically symmetrical structure, and the spaces between the convex roll 12 and the concave roll 15 are connected by an air shielding portion 16 made of a cylindrical foam.

The operation of the above configuration will be described. When an electric input is applied to the voice coil 5, the convex rolls 12 and 13 and the concave rolls 14 and 15 are connected by the air shielding portions 16, 17, 18, and 19 made of a cylindrical foam, If this foam is made of a flexible material such as urethane rubber, convex rolls 12, 13 are used.
The concave rolls 14 and 15 operate as a support for the cone diaphragm 7 without hindering the vertical amplitude movement of the cone diaphragm 7, and the air shields 16, 17, 18, and 19 serve as the cone diaphragm 7. Acoustically shields the sound emitted from the back. Therefore, when the cone diaphragm 7 oscillates upward, the convex rolls 12 and 13 are in the B state in the vibration state of the roll-shaped edge shown in (FIG. 6), that is, the air exclusion amount is U1. The concave rolls 14 and 15 are obtained by vertically reversing the state of C in the vibration state in the same figure, and the air elimination amount is U2. Next, when the cone vibration plate 7 swings downward, the convex rolls 12 and 13 are in the C state in the vibration state of the roll-shaped edge shown in FIG. The rolls 14 and 15 are obtained by vertically reversing the state of B in the vibration state shown in the figure, and the air removal amount is U1. That is, the total amount of air removed by one convex roll and one concave roll with respect to the vertical amplitude is always U1 + U2, and the asymmetry of air is eliminated.

(FIG. 3) shows the case of using the edge of this embodiment 14
It is a sound pressure frequency characteristic of a speaker having a cm diameter. (Figure 3)
As is apparent from the above, it can be seen that the second harmonic distortion is significantly reduced in the low frequency range of 100 Hz or less with respect to the characteristics of the conventional speaker shown in FIG.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a detailed view of the appearance of the edge portion in the second embodiment of the present invention. In the figure, the convex roll 20 and the concave roll 21 have a vertically symmetrical structure, and the spaces between the convex roll 20 and the concave roll 21 are connected by an air shielding portion 22 formed of a hollow hemispherical membrane. The operation of this embodiment is almost the same as that of the first embodiment. In the first embodiment, the air shield is made of foam such as urethane rubber. However, the foam has a large surface area in contact with air and is apt to undergo hydrolysis or deterioration due to ultraviolet rays, which is somewhat difficult in terms of durability. In this embodiment, the air shielding portion 22 is a hollow hemispherical film and is made of, for example, a material such as butyl rubber, which improves durability. Further, even if the shielding portion 22 is integrally formed of the same material as the rolls 20 and 21, there is no problem.

Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a plan view of a speaker according to the third embodiment of the present invention, in which 23 is a square diaphragm, 24 and 25 are convex roll edges, and 26 and 2.
Reference numeral 7 is a concave roll edge, 28, 29, 30, 31 are air-shielding portions of foam, and 32 is a frame. In this embodiment, the vibrating plate has a square shape, the two opposite sides, 24 and 25 are convex rolls, the other two opposite sides, 26 and 27 are concave rolls, and the convex roll and the concave roll are formed. Since the joints are connected by the air-shielding portions 28, 29, 20, 31 of the foam, the diaphragm operates as a support without disturbing the vertical amplitude movement of the diaphragm 23. The amount of air removed by the edge due to the vertical amplitude movement of the vibrating plate is the total of the convex rolls 24 and 25 and the concave rolls 26 and 27.
Similar to the above embodiment, the asymmetry of the air removal amount is improved.

[0017]

As described above, according to the present invention, the edge is divided into a plurality of pieces, for example, if one piece is a convex roll, the adjacent piece has a symmetrical structure with a concave roll. By connecting the divided piece with an air shield, the combined amount of air excluded from one edge piece and air excluded from the adjacent one piece with respect to the vertical amplitude of the diaphragm can be calculated. By making them equal, the second harmonic distortion of the sound pressure characteristic caused by the asymmetry of the air exclusion amount of the edge that has been conventionally generated can be significantly reduced, and a low distortion speaker can be provided.

[Brief description of drawings]

FIG. 1A is a structural cross-sectional view of a speaker according to a first embodiment of the present invention. (B) It is a top view of the speaker which concerns on the 1st Example of this invention.

FIG. 2 is a detailed external view of an edge portion of the speaker according to the first embodiment of the present invention.

FIG. 3 is a sound pressure frequency characteristic of a 14 cm diameter speaker adopting the edge of the present invention.

FIG. 4 is a detailed external view of an edge portion of the speaker according to the second embodiment of the present invention.

FIG. 5 is a structural cross-sectional view of a conventional speaker.

FIG. 6 is a diagram showing a vibration mode of an edge portion of a conventional speaker.

FIG. 7 is a sound pressure frequency characteristic of a 14 cm diameter speaker using a conventional edge.

FIG. 8 is a plan view of a speaker according to a third embodiment of the present invention.

[Explanation of symbols]

 5 voice coil 7 cone type diaphragm 11 edge 12, 13, 20 convex roll 14, 15, 21 concave roll 16, 17, 18, 19 air shield 22 hemispherical air shield 23 square diaphragm

Claims (7)

[Claims] 1. An edge formed by dividing the length direction into a plurality of pieces, wherein the adjacent pieces have a symmetrical structure, and the adjacent pieces are connected by an air shield. A loudspeaker comprising a diaphragm joined to the inner or outer circumference of the edge and a frame joined to the outer or inner circumference of the edge. 2. The speaker according to claim 1, wherein the diaphragm has a circular shape. 3. The speaker according to claim 1, wherein the diaphragm has a rectangular shape. 4. The diaphragm has a square shape and is opposed to each other.
4. The speaker according to claim 3, wherein one of the two pieces has the same shape and the other two opposite pieces have the same shape, and the two pieces have a symmetrical structure. 5. The speaker according to claim 1, wherein the divided pieces have a roll shape, and if one of the divided pieces is a convex roll, the adjacent piece has a symmetrical structure in which the adjacent pieces are concave rolls. 6. The speaker according to claim 1, wherein the air shielding portion is a foamed material such as urethane rubber. 7. The speaker according to claim 1, wherein the air shielding portion has a hemispherical shape.