JP2000270396A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a speaker with thin profile and excellent performance that is easily manufactured. SOLUTION: A curved board 1 is made of a foam synthetic resin, and has a size whose one side is about 150 mm and whose thickness is about 2 mm and whose radius of curvature is part of a large spherical face for example. A coat material made of a resin or the like and comparatively hard is coated or adhered to both sides of the curved board 1. A voice coil 3 is placed between ribs 2 on a concaved side that is a rear side of the curved board 1 and the voice coil 3 is fixed to the rear side of the curved board 1 by an adhesive. Then a yoke is fixed to the voice coil 3 and a permanent magnet (not shown) is fitted to the yoke.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker which can be suitably used for thin speakers for various uses.

[0002]

2. Description of the Related Art Hitherto, a commonly used speaker is a cone-shaped dynamic speaker, which reproduces sound by vibrating air using cone paper.

[0003]

However, this dynamic speaker has a large thickness because a horn-shaped cone paper also fixed to the frame must be attached via a cap in front of the voice coil fixed to the frame. I have to be.

Further, in order to output a loud sound, the cone paper must be vibrated greatly, which causes a problem that the transmitted sound is modulated.

The present applicant has already filed a patent application for a speaker using a curved plate obtained by bending a balsa material, for example, but it may be difficult to prepare a curved plate depending on the material.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a speaker that is easy to manufacture, that is thin, hardly modulates, and that faithfully reproduces sound. It is difficult to produce a product with uniform sound quality.

[0007]

According to the present invention, there is provided a speaker according to the present invention, wherein a coating material is coated on a surface of a curved plate molded from a foamed synthetic resin, and a voice coil is provided on a part of the curved plate. It is characterized by being fixed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. 1 is a perspective view as viewed from the front, FIG. 2 is a perspective view as viewed from the rear, and FIG. 3 is a cross-sectional view. The curved plate 1 is made of a foamed synthetic resin.
It has a size of about mm and is a part of a spherical surface having a large radius of curvature. A relatively hard coating material made of, for example, resin is applied or attached to both surfaces of the curved plate 1. A plurality of ribs 2 made of the same material as the curved plate 1 are integrally provided on the concave surface of the back surface of the curved plate 1, for example. The curved plate 1 can be manufactured by injection molding or a plate-like plate can be formed by hot pressing. However, according to the injection molding, the rib 2 can also be formed integrally. Rib 2
The voice coil 3 is arranged on the curved plate 1 therebetween, and the voice coil 3 is fixed to the back surface of the curved plate 1 with an adhesive.
A yoke (not shown) is fixed to the voice coil 3, and a permanent magnet is attached to the yoke. The yoke and the permanent magnet may be supported by a frame or the like on which the curved plate 1 is mounted.

In this case, when the voice coil 3 is disposed between the ribs 2 as in the embodiment and is accommodated in the concave portion of the curved plate 1, the thickness of the curved plate 1 is added to the thickness of the voice coil 3. Only a very thin speaker can be obtained. Rib 2
Plays a role in maintaining the shape of the curved plate 1 and inducing a wave motion in the curved plate 1 and can be stretched in any direction.

Here, when a voice current flows through the voice coil 3 through a lead wire, a vibration corresponding to the voice is generated in the voice coil 3 by an electromagnetic action with the yoke 4 through which the magnetic flux from the permanent magnet flows. The vibration is transmitted to the curved plate 1. Since the curved plate 1 is reinforced by the ribs 2, the vibration of the curved plate 1 is suppressed, and most of the sound energy is transmitted to the curved plate 1 as waves. The waves cause collisions between molecules in the curved plate 1, that is, in the soft foamed synthetic resin, and are converted into voices. In particular, the curving causes distortion in the molecular arrangement, which increases the sound pressure level. Sound is emitted from the curved plate 1. According to various experiments, it has been confirmed that the sound level changes according to the degree of curvature of the curved plate 1. In this case, since the sound is not pushing out the air by the vibration of the curved plate 1, the sound has no particular directivity and is transmitted to all directions.

Since the surface of the curved plate 1 is coated with a coating material made of, for example, a synthetic resin which is harder than the curved plate 1, sound is transmitted to the air well. This is similar in principle to the fact that, for example, the resonance of the violin slightly changes the sound quality depending on the type of paint applied to the surface of the violin.

It has been confirmed that when the curvature of the curved plate 1 is changed, the collision rate between molecules changes and the sound pressure level changes. However, the curvature is appropriately adjusted in consideration of the size of the curved plate 1 and the like. Is preferably selected. In the embodiment, an example in which the curved plate 1 is bent in a three-dimensional direction has been described.

The voice coil 3 can be mounted at any position on the convex side of the curved plate 1, or a plurality of voice coils 3 may be mounted on one curved plate 1. Further, either the convex side or the concave side of the speaker may be the front side.

[0014]

As described above, the loudspeaker according to the present invention is mainly made of foamed synthetic resin, so that it can be easily manufactured, is extremely thin, can be manufactured at low cost, and has good performance.

[Brief description of the drawings]

FIG. 1 is a perspective view as viewed from the front.

FIG. 2 is a perspective view seen from the rear.

FIG. 3 is a sectional view.

[Explanation of symbols]

 1 curved board 2 rib 3 voice coil

Claims (6)

[Claims] 1. A speaker characterized in that a coating material is coated on a surface of a curved plate molded from a synthetic resin foam, and a voice coil is fixed to a part of the curved plate. 2. The loudspeaker according to claim 1, wherein a plurality of ribs are provided on the concave side of the curved plate in order to maintain the shape of the curved plate. 3. The speaker according to claim 2, wherein the rib is made of the same material as the curved plate. 4. The loudspeaker according to claim 2, wherein the rib is disposed at a position where a wave input from the voice coil to the curved plate is easily transmitted along the curved plate. 5. The speaker according to claim 1, wherein the voice coil is fixed to the curved plate via a short cylindrical connecting member. 6. The speaker according to claim 1, wherein a yoke and a permanent magnet are attached to the voice coil.