JPH0654998B2 - Vibration plate for flat speaker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a diaphragm for a flat speaker.

Conventional configuration and its problems Conventionally, a speaker diaphragm having a cone shape is often used. This is because the cone shape is structurally extremely strong in the vibration direction, and a wide reproduction band can be obtained even if a relatively elastic material such as paper or plastics is used.

However, a speaker with a large dent, such as a cone,
Depending on the degree, a peak dip was generated on the sound pressure frequency characteristic, which hindered the flatness of the sound pressure frequency characteristic. In order to solve these problems, in recent years, a plane vibration plate using a honeycomb sandwich structure or the like has been studied and put into practical use. However, flat diaphragms require complicated manufacturing processes such as a honeycomb structure in order to secure the necessary reproduction frequency band, and there are many types of components, adhesives, etc. Is.

Therefore, there has been a demand for a diaphragm for a flat speaker that is low in cost and has characteristics equivalent to those of a conventional flat speaker.

SUMMARY OF THE INVENTION In view of the above drawbacks, the present invention provides a diaphragm for a flat speaker having a simple structure and a flat sound pressure frequency characteristic without using a complicated flat diaphragm such as a sandwich structure.

Configuration of the Invention The present invention is a cone-shaped outer peripheral portion having a flat portion perpendicular to the axial direction, the first diaphragm having a V groove in the outer peripheral portion, and a flat portion perpendicular to the axial direction on the outer peripheral portion. And the inverted triangular pyramids are continuously arranged in a radial pattern, and each inverted triangular pyramid is fitted and bonded to each V groove of the first diaphragm, and a reinforcing wall in the circumferential direction is provided in the middle of the V groove. A second vibrating plate configured to be formed, and a surface plate is adhered to a flat portion of the second vibrating plate and an inverted triangular pyramid of the second vibrating plate to form a flat acoustic radiation surface. ing.

The diaphragm for a flat speaker configured as described above has an extremely simple structure and has a unique effect of obtaining sound pressure frequency characteristics equivalent to those of a conventional flat speaker.

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

FIG. 1 shows a shape of a first diaphragm of a flat speaker diaphragm according to an embodiment of the present invention. FIG. 1 (a) is a perspective view of the first diaphragm, and FIG. b) is A- in Fig. 1 (a)
It is an A'line sectional view.

In FIG. 1, 1 is a first diaphragm, and 1b, 1c, 1
The surface including d has a straight cone shape, the flat portion 1e provided on the outermost peripheral portion of the first diaphragm 1 is perpendicular to the vibration direction (axial direction), and the entire outer peripheral portion is V-groove 1 formed by 1a, 1c, 1b, 1c 'over the circumference
have f.

FIG. 2 shows a second diaphragm in this embodiment,
2 (a) is the same perspective view, and FIG. 2 (b) is B- in FIG. 2 (a).
It is a B'line sectional drawing.

In FIG. 2, 2 is a second diaphragm, 2a, 2a ',
Each of the triangles formed by 2b and 2b fits into the V groove 1f of the first diaphragm 1 shown in FIG. 1, has a substantially inverted triangular pyramid shape connected to the center, and has a middle of the V groove 1f. A circumferential reinforcing wall 2c (vertical line portion) is formed on the. In the present embodiment, the bottom side of the inverted triangular pyramid is not extended to the center, and the inner diameter portion 2d having the same diameter as the voice coil bobbin is used as a boundary to form a shallow dome shape that does not affect the sound pressure frequency characteristic. This is because the reverse dome portion 2e can be separated and finally bonded so that a gauge for setting the voice coil bobbin at a correct position can be put in and taken out from the upper surface of the diaphragm, and a defective rate in manufacturing can be reduced. It is a thing.

Generally, in order to expand the reproduction band of the flat diaphragm, it is required that the bending strength in the radial direction is large. Therefore, in this embodiment, the ribs are radially formed so that the bending strength at the joining point of the first diaphragm and the second diaphragm, that is, the driving point is maximized.

However, in order to maximize the effect of the radial ribs, it is necessary to reinforce each other in the circumferential direction and fix each rib. Therefore, in this embodiment, 2a and 2 in FIG.
Ideally, the radial ribs formed by the V groove 1f of the first diaphragm and the inverted triangular pyramid of the second diaphragm are fixed in the circumferential direction by the triangular reinforcing wall 2c formed by b and 2a '. It forms a reinforcing structure.

Further, the flat surface portion 2f provided on the outer circumference of the second diaphragm 2 in FIG. 2 is bonded to the flat portion 1e provided on the outermost circumference of the first diaphragm 1 to reinforce the outside of the driving point. It is structured.

FIG. 3 shows the overall construction of this embodiment, and FIG. 3 (a)
FIG. 3 is a perspective view of the flat speaker diaphragm of the present embodiment, and FIG.
(b) is a sectional view of the same.

As described above, the first and second diaphragms are adhered to each other, and further, the front plate 3 shown in FIG.
Adhere to the entire surface excluding e. The cone inner peripheral portion 1d of the first diaphragm 1 is bonded to the voice coil bobbin 4 and driven by a magnetic circuit.

With this configuration, the acoustic radiation surface becomes a complete flat surface except the central inverted dome portion 2e, and a flat sound pressure frequency characteristic can be obtained.

Since the first and second diaphragms 1 and 2 and the surface plate 3 constituting the diaphragm can be easily manufactured by thermoforming a plastic film, papermaking of pulp, etc., a lightweight diaphragm can be obtained at low cost. It has the advantage that

EFFECTS OF THE INVENTION As described above, the present invention provides a planar acoustic radiation surface by combining a plurality of diaphragms and a structure for reinforcing the joint portion of the first and second diaphragms in the radial direction and the circumferential direction. By doing so, it is possible to provide a diaphragm for realizing a speaker having a flat sound pressure frequency characteristic and a wide reproduction band. Further, as compared with the conventional example, the manufacturing method is simple, the weight can be reduced, and the low cost and high efficiency flat speaker is provided.

[Brief description of drawings]

FIG. 1 (a) is a perspective view showing a first diaphragm of a diaphragm for a flat speaker according to an embodiment of the present invention, and FIG. 1 (b) is a first diaphragm.
2A is a perspective view showing the second diaphragm, and FIG. 2B is a BB ′ line in FIG. 2A. A sectional view, FIG. 3 (a) is a perspective view of the diaphragm for a flat speaker, and FIG. 3 (b) is a sectional view. 1 ... 1st diaphragm, 1e ... flat part, 1f ... V groove,
2 ... second diaphragm, 2c ... reinforcing wall, 3 ... surface plate.

Claims (1)

[Claims] 1. A cone-shaped first diaphragm having an outer peripheral portion having a flat portion perpendicular to the axial direction and having a V groove in the outer peripheral portion, and an outer peripheral portion having a flat portion perpendicular to the axial direction. In addition, the inverted triangular pyramids are continuously arranged radially, and each inverted triangular pyramid is fitted and bonded to each V groove of the first diaphragm to form a circumferential reinforcing wall in the middle of the V groove. A second vibrating plate configured as described above, and a flat plate of the second vibrating plate and a surface plate bonded on the inverted triangular pyramid of the second vibrating plate to form a flat acoustic radiation surface. Characteristic diaphragm for flat speakers.