JPS6149594A - Diaphragm for plane speaker - Google Patents

Abstract

PURPOSE:To obtain speaker which has a flat acoustic pressure frequency characteristic and a wide reproducing band, by combining plural diaphragms to obtain a plane acoustic radiating surface and reinforcing the junction part between diaphragms in the radial direction and the peripheral direction. CONSTITUTION:The first diaphragm 1 is conical and is provided with V grooves 1f formed with angles 1a, 1b... radially and continuously in the peripheral direction, and a flat part 1e provided in the outside peripheral edge is orthogonal to the axial direction. The second diaphragm 2 has a plane part 2f orthogonal to the axial direction in the outside peripheral part and is provided with inverted triangular prisms continuously and radially, and triangular parts formed with angles 2a, 2a', and 2b are fitted to V grooves 1f of the diaphragm 1 respectively and are connected to their centers to form approximately inverted triangles, and reinforcing walls 2c in the peripheral direction are formed in middles of V grooves 1f. Diaphragms 1 and 2 are adhered to each other in this manner, and a ring-shaped surface plate is adhered to the whole of the surface except an inverted dome part 2e in the center.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a diaphragm for a flat speaker.Conventional structure and problems thereofCone-shaped diaphragms for speakers have traditionally been widely used. There is. This is because the cone shape has extremely high structural strength in the vibration direction, and a wide range of reproduction frequency bands can be obtained even when using relatively low elastic materials such as paper and plastics.

However, speakers with cone-shaped recesses, etc.
Depending on the extent of this, a peak dip occurs in the sound pressure frequency characteristics, which impedes flatness.

In order to solve these problems, in recent years, planar diaphragms using a honeycomb sandwich structure or the like have 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! Currently, there are many types of components, adhesives, etc., and an increase in weight and cost is unavoidable. Therefore, there has been a desire for a diaphragm for flat speakers that is low cost and has characteristics equivalent to those of conventional flat speakers.

OBJECTS OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a diaphragm for a flat speaker that has a simple structure and a flat sound pressure frequency characteristic without using a complex structure such as a sandwich structure.

Structure of the Invention The present invention provides a cone-shaped cone in which grooves are continuously provided radially in the circumferential direction from the inner circumferential end to the outer circumference, and the outer circumferential end is a flat part perpendicular to the axial direction. A diaphragm having a flat part perpendicular to the axial direction on the outer periphery, and inverted triangular pyramids are arranged radially in succession, and each inverted triangular pyramid is fitted into each groove of the first diaphragm. a second diaphragm bonded together to form a circumferential reinforcing wall in the middle of the V groove;
The structure includes a flat part of the second diaphragm and a surface plate glued onto the inverted triangular pyramid of the second diaphragm.This makes the sound radiation surface substantially flat and has an extremely simple structure. Despite this, it has the unique effect of being able to obtain sound pressure frequency characteristics that are equal to or higher than those of conventional planar speakers.

DESCRIPTION OF ACTUAL EXAMPLE An actual example of the present invention will be described below with reference to the drawings.

Fig. 1 shows the shape of a first diaphragm constituting a diaphragm for a flat speaker in a practical example of the present invention.
is a perspective view of the first diaphragm, and FIG. 1 is a perspective view of the first diaphragm.
It is a sectional view taken along the A/ line.

In Fig. 1, reference numeral 1 denotes a first diaphragm, which has grooves radially continuous in the circumferential direction from the inner circumferential end to the outer circumference, that is, grooves 1 a , 1 b , 1 c , 1 c' over the entire circumference.
.

It has a cone shape with Vgif formed by 1d and 1'd'. Further, the flat portion 1e provided at the outer peripheral end is perpendicular to the vibration direction (axial direction).

Figure 2 shows the second diaphragm in this example.
Figure 2 a is a perspective view of the second diaphragm, Figure 2 is Figure 2 a
It is a BB/ line sectional view of.

In FIG. 2, reference numeral 2 denotes a second diaphragm, which has a flat surface 2f perpendicular to the axial direction on its outer periphery, and has inverted triangular pyramids arranged radially in series. That is, 2a.

The triangles formed by 2a' and 2b are each fitted into the groove 1f of the first imaging plate 1 shown in FIG.
It has a substantially inverted triangular pyramid shape connected to the center, and a reinforcing wall 2c (vertical line portion) in the circumferential direction is formed in the middle of the groove 1f. In this example, the base of the inverted triangular pyramid is not extended at the center, but the center side is made into a shallow dome shape that does not affect the sound pressure frequency characteristics, with the inner diameter part 2d having the same diameter or more as the voice coil bobbin as the border. . By configuring this inverted dome portion 2e to be separated and bonded last, the gauge for setting the voice coil bobbin in the correct position can be inserted and removed from the top surface of the imaging plate, reducing the defective rate in the manufacturing process. It is for the purpose of

Generally, in order to expand the playback frequency reduction of a flat speaker, the bending strength in the radial direction of the imaging plate is required to be large. Therefore, in this example, the structure is such that the bending strength at the joint point of the first imaging plate 1 and the second diaphragm 2, the bending driving point, is the highest, and 1/2 bars are arranged radially. ing. In order to maximize the effect of the twisted radial ribs,
It is also necessary to reinforce in the circumferential direction to prevent opening and closing between the ribs. Therefore, in this example, 2a in Figure 2.

The triangular reinforcing wall 2C formed by 2b and 2a' fixes the radial groove 1f of the first diaphragm in the circumferential direction and the radial groove 1f of the second diaphragm, which is formed by an inverted triangular pyramid. It forms a reinforcing structure.

¥1: In addition, the flat part 2fj provided on the outer periphery of the second imaging plate 2 in FIG. The structure is designed to reinforce the

Figure 3 U: Shows the overall structure of the Kinomine example; Figure 3 a
3 is a perspective view of the flat diaphragm C according to this embodiment, and FIG. 3 is a sectional view of the same.

As mentioned above, the first and second diaphragms are bonded together, and the annular surface plate 3 shown in FIG. “Ru.

The inner circumference of the first diaphragm 1, 1d, is bonded to the voice coil bobbin 4, and is driven by a magnetic circuit (not shown).

With the above configuration, J: Ri Acoustic Radiation 11! ]]
' is completely flat except for the inverted dome 2e at the center, and a flat sound pressure frequency characteristic can be obtained.

In addition, the diaphragm according to the present invention is made of wood pulp,
Alternatively, by molding a plastic film, it can be easily manufactured using lightweight materials, and a high-performance flat diaphragm can be obtained at low cost.

Effects of the Invention As described above, the present invention obtains an elliptical acoustic radiation surface by combining a plurality of diaphragms, and also connects the first and second diaphragms in the diametrical direction and in the radial direction. By adopting a reinforcing structure, it is possible to provide a diaphragm that realizes a speaker with flat sound pressure frequency characteristics and a wide reproduction band. ! The manufacturing method is simpler and the weight can be reduced compared to the conventional examples, and a low-cost, high-efficiency flat speaker can be provided.

[Brief explanation of the drawing]

FIG. 1a is a perspective view showing a first diaphragm of a flat speaker diaphragm according to an embodiment of the present invention;
Figure 2a is a perspective view showing the second diaphragm, Figure 2 is a cross-sectional view taken along line E-B of Figure 2a, Figure 3a is the same plane. FIG. 3 is a perspective view of the speaker diaphragm, and FIG. 3 is an open-plan cross-sectional view. 1...First diaphragm, 1e...Flat portion, 1f...■Groove, 2...Second diaphragm, 2a... ... Reinforcement wall, 2f ... Plane part,
3... Surface plate. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure fo. Figure 2

Claims (1)

[Claims] A first diaphragm having a cone shape in which V grooves extending from the inner circumferential end to the outer circumference are continuously provided radially in the circumferential direction, and whose outer circumferential end is a flat part perpendicular to the axial direction; The part has a flat part perpendicular to the axial direction, and inverted triangular pyramids are successively arranged radially, each inverted triangular pyramid is fitted and bonded to each V groove of the first diaphragm, and the V a second diaphragm forming a reinforcing wall in the circumferential direction in the middle of the groove; and a surface plate bonded to a flat part of the second diaphragm and an inverted triangular pyramid of the second diaphragm. A diaphragm for a flat speaker characterized by comprising: