JPH03213098A - Loudspeaker - Google Patents

Abstract

PURPOSE:To enlarge directivity to a hearing point and to improve sound quality by constituting a loudspeaker so that the radius of right and left cone surface can be equal and the curvature of right and left cone curves can be asymmetric with respect to the center line of a cone-shaped diaphragm. CONSTITUTION:The plane of a diaphragm 5A is circular. However, on a cross section through the center line, a curvature R2 of the right cone curve is made larger than a curvature R1 of the left cone curve. A hearing point Q mainly receives sounds directly from the faced cone surfaces. An arrow shown by a broken line and a real line in a figure shows the border of the direct sounds to reach the hearing point Q. Like this border line, for the loudspeaker, the effective area of the vibration surface on the diaphragm 5A facing to the hearing point Q and the direct sounds are increased in comparison with the conventional loudspeaker. Therefore, the directivity to the hearing point Q is enlarged, the flatness of the frequency characteristic in the high area of the direct sounds to be radiated to the hearing point Q is improved and the sound quality can be widely improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a speaker used in the field of audio equipment such as in-vehicle audio.

2. Description of the Related Art Conventionally, a cone-shaped diaphragm has generally been used as a diaphragm constituting this type of speaker.

FIG. 3 shows the configuration of such a conventional speaker, where 1 is a bottom plate, 2 is a magnet, and 3 is an upper plate. The bottom plate 1, the magnet 2, and the upper plate 3 constitute a magnetic circuit. are doing. 4 is a frame, which is fixed to the magnetic circuit described above. 5 is a cone-shaped diaphragm whose outer periphery is fixed to the frame 4; 6 is a voice coil inserted into the magnetic gap of the magnetic circuit; 7 is a suspension whose outer periphery is fixed to the frame 4;
The inner circumferences of the suspension 7 and the diaphragm 6 are connected to the voice coil/I/6. P is the listening point.

Making the diaphragm 5 cone-shaped in this way is effective in improving rigidity, and a lightweight material such as a paper pulp cone can be used.

Furthermore, by using a curved cone as shown in FIG. 3, it is possible to improve the frequency characteristics, particularly the flatness of the frequency characteristics in a high frequency range.

Figure 4 shows the structure of another conventional cone-shaped diaphragm, in which the shape of the center of the cone is partially changed to disperse the resonance of the diaphragm, thereby improving frequency characteristics. It is.

Problems to be Solved by the Invention However, in in-vehicle audio and the like, since the listening point is off the speaker axis, characteristic changes due to directivity pose a problem. Directivity is greatly influenced by the diameter and shape of the diaphragm, and the curvature of the curved cone is also an important factor.

In other words, when the curvature of the curved cone is made smaller in FIG. Even if the frequency characteristics of the range could be improved, the problem was that the sound quality deteriorated.

The present invention solves these conventional problems,
The object of the present invention is to provide a speaker that improves directivity while improving the flatness of high frequency characteristics, and that provides high sound quality even at off-axis listening points.

Means for Solving the Problems In order to solve the above problems, the present invention configures a speaker in which the radii of the left and right cone surfaces are equal with respect to the center line of the cone-shaped diaphragm, and the curvatures of the left and right cone curves are asymmetrical. It is something.

Therefore, according to the present invention, by configuring the cone curves of the diaphragm to be different on the left and right sides, when a speaker is installed with the part of the cone curve having a large curvature facing the listening point, the vibration surface facing the listening point is Because the effective area increases, the direct sound increases and the directivity towards the listening point becomes wider.
This improves the sound quality.

Embodiment FIG. 1 shows the configuration of a speaker according to a first embodiment of the present invention. The same parts as those shown in FIG. To explain this, in the figure, six people are cone-shaped diaphragms, R1 and R2 are the respective curvatures of the left and right cones with respect to the center line of the five diaphragms, and Q is the listening point. As shown in the figure, the plane of the diaphragm 5m is circular, but in a cross section passing through the center line, the curvature R2 of the right cone curve is larger than the curvature R1 of the left cone curve. However, the broken lines at and \ indicate the curvature R1 of the cone having the same curvature on the left and right sides according to the conventional configuration.

Here, the listening point Q mainly receives direct sound from the opposing cone surface, but in a speaker with a conventional configuration, a portion of the sound is blocked by the right cone surface. In FIG. 1, the arrows shown by broken lines and solid lines indicate the boundaries of direct sound reaching the listening point Q.

As shown by this boundary line, it can be seen that the effective area of the vibration surface of the diaphragm 5m facing the listening point Q is increased in the speaker according to this embodiment compared to the conventional one, and the direct sound is increased.

Therefore, the directivity with respect to the listening point Q is expanded ν, and by setting the curvature R1 of the left side of the transversal plate 5A to an appropriate value, the flatness of the high frequency characteristic of the direct sound radiated to the listening point Q is improved. This can greatly improve the sound quality.

Incidentally, the curvatures R1 and R2 are: i, 2 each, which increases the effective area of the diaphragm facing the listening point Q;
It may also be composed of curvatures of more than one type.

FIG. 2 shows the configuration of a speaker according to a second embodiment of the present invention, and in the figure, the same parts as those shown in FIG. 3 are given the same numbers and the explanation will be omitted.

This example uses frame 4. The difference from the first embodiment is that the planes of the diaphragm 6B are both ellipsoids, and the ellipse has different curvatures R1 and R in the major axis direction and the minor axis direction, respectively.
Two configurations are possible.

Oval speakers are increasingly being used as in-vehicle speakers because they can save space when installed, but they have a problem in that they have narrow directivity in the major axis direction. Therefore, by configuring different curvatures R1 and R2 in the major axis direction as shown in FIG. 2, a large improvement effect can be obtained.

Effects of the Invention As is clear from the above-mentioned embodiments, the present invention provides a speaker with a groove in which the radius of the left and right cone surfaces are equal with respect to the center line of the cone-shaped diaphragm, and the curvature of the cone curve is asymmetric.
By installing the part of the cone curve with a large curvature as the listening point side, the following effects can be obtained.

(1) The direct sound radiated to the listening point off the speaker axis increases and the directivity is improved.

(2) By setting the cone curve curvature on the side facing the listening point to an optimal value, the flatness of the high frequency characteristic of the direct sound received by the listening point can be improved without deteriorating the directivity.

(3) Due to the effects of (1) and (2) above, it is possible to provide a speaker with very high quality acoustic characteristics even in a sound field where the listening point in the interior of a car or the like is far off the speaker axis.

(4) Furthermore, the speaker according to the present invention can be manufactured by simply improving the mold for the cone-shaped diaphragm, making it possible to provide a speaker that is inexpensive and excellent in mass production.

[Brief explanation of drawings]

FIGS. 1(&) and (b) are a plan view and a cross-sectional view of the speaker according to the first embodiment of the present invention taken along the X-0-Y line, and FIGS. 2(a) and (b) are A plan view of the speaker in the second embodiment and a sectional view thereof along the x-oy line, FIG. 3 is a sectional view of a conventional speaker, and FIG. 4 <11>, (b) is a speaker in another conventional example. FIG. 2 is a plan view of the diaphragm of the person and a cross-sectional view taken along the line -0-B of the person. 1...Bottom plate, 2...Magnet,
3... Upper plate, 4... Frame,
5mm 15B... Cone-shaped diaphragm, 6...
Boinukoil, 7...Sanupennyon, R1, R
2 rivers... curvature.

Claims (1)

[Claims] A voice coil is inserted into the magnetic gap of a magnetic circuit fixed to a frame, and the voice coil is coupled to the center of a suspension and a cone-shaped diaphragm whose outer peripheries are fixed to the frame, respectively, and the cone-shaped diaphragm is aligned with the center line. A speaker with a shape in which the radius of the left and right cone surfaces is equal, and the curvature of the left and right cone curves is asymmetric.