JP3030907B2 - Speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker having a circular outer shape of a diaphragm.

[0002]

2. Description of the Related Art Flattening of speaker frequency characteristics has been one of the most important items to be considered in designing a circuit. However, with the progress of digitalization of circuits such as the audio-video market today, higher sound quality with flatter characteristics has been achieved. Speakers are required.

[0003] A conventional speaker will be described below.
FIG. 6 shows the structure of a conventional speaker. FIG.
Shows a plan view of a diaphragm used in a conventional speaker,
FIG. 8 shows a cut sectional shape in an arbitrary direction on a plane passing through the center axis of the diaphragm. 6, a ring-shaped magnet 2 and a top plate 3 are arranged on a bottom plate 1 having a cylindrical center pole 1a at the center, and a magnetic gap is formed between the inner periphery of the top plate 3 and the center pole 1a of the bottom plate 1. 4 is formed. Top plate 3
The frame 5 is joined thereto, and the voice coil 6 is fixed to the frame 5 via a damper 7 so that the winding portion of the voice coil 6 is located at the center of the magnetic gap 4. The cylindrical bobbin of the voice coil 6 and the central through hole of the diaphragm 8 are bonded together, and the edge of the diaphragm 8 is bonded and fixed to the frame 5. 9 is a cancel magnet, 10 is a shield cover, and 11 is a dust cap.

The principle of operation of the loudspeaker constructed as described above will be described below. When an electric input is applied, the voice coil 6 located in the center of the magnetic gap 4 in the parallel magnetic field generates a force in the vertical direction according to Fleming's left-hand rule. The force is transmitted from the voice coil 6 to the diaphragm 8 via the cylindrical bobbin. The diaphragm 8 generates sound by vibrating the air on the front surface.

The structure and shape of the diaphragm 8 are as shown in a plan view of FIG. 7, and a cross section cut in an arbitrary direction on a plane passing through the central axis of the diaphragm 8 is shown in FIG. The conventional diaphragm 8 has a cone portion 8a and an edge portion 8 as shown in FIG.
The size of the bonding portion 8c of b is the same as that of the circumference and bonded together so as to be concentric with each other in a circular shape. Therefore, when cut on all surfaces passing through the central axis of the through hole of the diaphragm 8, the cross-sectional shape is the same.

[0006]

In the conventional loudspeaker having the above-described configuration, the axis symmetric modes become equal in the divided resonance region near the high frequency limit frequency in the frequency characteristic, and the peak and dip in the frequency characteristic are obtained. Occur more remarkably. The flatness is determined by changing the size and shape of the cone portion 8a and the edge portion 8b, or by changing the detailed specifications (materials, forming conditions, etc.) in the forming process of the cone portion 8a. I was However, the former involved mold costs and the latter was less effective.

[0007]

In order to solve this problem, a speaker according to the present invention has a configuration in which the outer peripheral portion of the cone portion and the inner peripheral portion of the edge portion constituting the circular diaphragm have a configuration of a bonding portion.
A structure in which a wide bonded portion and a narrow bonded portion are provided, and these are alternately arranged in the circumferential direction.

[0008]

With this diaphragm structure, compared to the conventional diaphragm that is bonded with a uniform width across the entire circumference of the cone portion and the edge portion, the split resonance in the vicinity of the high limit frequency is superior in frequency characteristics. The peak and dip in the region are reduced, and a flatter frequency characteristic is obtained. This is because the resonance sharpness of the peak and the dip in the frequency characteristic is reduced by giving the outer periphery of the cone portion an uneven mass and an internal loss at the time of resonance of the diaphragm.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a half sectional view showing an embodiment of the speaker according to the present invention, FIG. 2 is a rear view of the diaphragm, and FIGS. 3 and 4 are sectional views of main parts of the diaphragm.

In FIG. 1, reference numeral 21 denotes a bottom plate having a center pole 22 at the center; 23, a magnet on a ring disposed on the bottom plate 21; 24, a top plate disposed on the magnet 23;
5 is a cancel magnet arranged on the bottom surface of the bottom plate 21, 26 is a shield cover over them, 27 is a magnetic circuit composed of these, 28 is a magnetic gap formed by the magnetic circuit 27, and 29 is a magnetic gap formed by the magnetic circuit 27. A frame 30 connected to the upper portion of the magnetic circuit 27, a circular diaphragm 30 whose peripheral edge is connected to the peripheral portion of the frame 29, and a numeral 31 connected to the center of the diaphragm 30 and eccentric to the magnetic gap 28 32 is a damper that supports the middle part of the voice coil 31, and 33 is a dust cap that is coupled to the upper end surface of the voice coil 31.

As shown in FIG. 2, the diaphragm 30 includes a cone portion 30a and an edge portion 30b.
a wide bonding portion 30c as a bonding portion with the cone portion 30a on the inner peripheral portion of the b, and a wide bonding portion 3
0d are alternately arranged in the circumferential direction.

FIGS. 3 and 4 show cross sections of the wide bonded portion 30c and the narrow bonded portion 30d.

As shown in FIGS. 3 and 4, the cone 3
Since the bonding width dimension and area of the edge portion 30b at the outer periphery of 0a are unequally set in the circumferential direction, each resonance mode becomes unbalanced and occurs near the high frequency limit frequency and in the divided resonance region. The respective resonance sharpnesses of the plurality of peaks and dips are reduced, and a flatter sound pressure frequency characteristic is obtained.

The sound pressure frequency characteristics of the speaker using the diaphragm 30 according to the present embodiment and the speaker using the conventional diaphragm shape are compared with FIG. As is apparent from FIG. 5, the speaker according to the present embodiment has a remarkable effect in flattening the sound pressure frequency characteristics in the divided resonance region.

[0016]

As described above, according to the present invention, in a speaker using a circular diaphragm, the configuration of the bonding portion between the outer periphery of the cone portion and the inner periphery of the edge portion constituting the circular diaphragm has a wide width. Part and a narrow bonding part, and a speaker is formed using a diaphragm having a shape in which they are alternately arranged in the circumferential direction, so that the conventional diaphragm production process can be used as it is, It is possible to realize a speaker having a flat sound pressure frequency characteristic without increasing material cost.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing the structure of a speaker according to an embodiment of the present invention.

FIG. 2 is a rear view of the diaphragm in the embodiment.

FIG. 3 is a view showing the diaphragm in FIG.
Cross section in direction

FIG. 4 is a cross-sectional view taken along the line BO in FIG. 2;

FIG. 5 is a sound pressure frequency characteristic diagram of the present invention and a conventional speaker.

FIG. 6 is a half sectional view showing a structure of a speaker in a conventional example.

FIG. 7 is a rear view of a speaker diaphragm in a conventional example.

FIG. 8 is a cross-sectional view of a speaker diaphragm in an AO direction according to a conventional example.

[Explanation of symbols]

 27 Magnetic Circuit 28 Magnetic Air Gap 29 Frame 30 Diaphragm 30a Cone 30b Edge 30c Wide Bonded Part 30d Small Bonded Part 31 Voice Coil

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04R 7/20

Claims (1)

(57) [Claims] In a loudspeaker using a circular diaphragm, the outer peripheral portion of the cone portion and the inner peripheral portion of the edge portion constituting the circular diaphragm have a wide bonding portion and a narrow bonding portion. A loudspeaker using a diaphragm, characterized in that a matching portion is provided, and they are alternately arranged in a circumferential direction.