JPH01253399A - Motor driven flat driving loudspeaker - Google Patents

Abstract

PURPOSE:To miniaturize a loudspeaker provided with a wire ring consisting of conductive foil on its diaphragm and, at the same time, to prevent the occurrence of divided vibrations by constituting the diaphragm by laminating plural diaphragms where weightings are respectively performed against the bits of digital signals. CONSTITUTION:Substrates A-A''' of the diaphragm of this loudspeaker are formed to have different areas and conductive layers B-B''' are formed by executing printing or etching on respective substrates. This diaphragm is constituted by laminating the substrates respectively provided with the conductive layers. Each of the conductive layers B-B''' is composed of wire rings 1, 2, 3, 4 and 5' and 5'' respectively corresponding to 2<0>, 2<1>, 2<2>, 2<3> and 2<4> bits. When the diaphragm is constituted of two such base plates, the area of the diaphragm becomes the 1/2 of that of the conventional example and, when three such base plates are used, the area of the diaphragm becomes the 1/3. Therefore, when such constitution is used, the rigidity of the diaphragm can be increased and divided vibrations which are apt to be produced by such kind of diaphragm can be prevented, in addition to the area being reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrodynamic planar drive speaker, and more particularly to a speaker suitable for applying a digital signal to an input terminal and converting this signal into an analog to generate sound. .

(Prior Art) Conventionally, a speaker has been proposed in which a digital signal is input directly to an input terminal of the speaker to generate an analog-like signal in the speaker. However, this type of speaker has the problem of weighting corresponding to the bits in the digital signal, which has the disadvantage of complicating the structure of the speaker.

(Problem to be Solved by the Invention) Generally, in an electrodynamic planar drive speaker, weighting of the driving force corresponding to the weight of the focus signal is Bj! i
(B: magnetic flux density, l: effective wire length, i: current flowing through the wire) or a combination thereof.

In this case, according to the idea of the invention described separately by the present inventor, part of the weight can be borne by the power supply side, making it possible to reduce the number of wire wheels.

However, supplying a large current to the diaphragm requires increasing the cross-sectional area of the wire ring to accommodate this, resulting in the problem that although the wire length becomes shorter, the area of the diaphragm hardly changes. occured.

The present invention was proposed in order to improve the above-mentioned drawbacks, and its purpose is to provide a speaker whose structure is miniaturized and whose characteristics prevent the occurrence of split vibration. .

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a speaker having a wire made of conductive foil on a diaphragm, in which each bit of a digital signal is weighted. The gist of the invention is an electrodynamic planar drive speaker characterized by being constructed by laminating a plurality of diaphragms.

(Function) Since the speaker diaphragm of the present invention is formed by laminating, the area of the diaphragm is 1/2 compared to that of a conventional speaker diaphragm.
Since the following can be achieved, it is possible to downsize the speaker and prevent the occurrence of split vibration.

(Example) Next, an example of the present invention will be described. Note that the embodiments are merely illustrative, and it goes without saying that various changes and improvements can be made without departing from the spirit of the present invention.

FIG. 1 shows an embodiment of the diaphragm of the present invention. In the figure, A indicates a substrate portion of the diaphragm, and B indicates a conductor portion formed on this substrate. Also, 1 is the wire corresponding to the 2° bit, 2 is the wire corresponding to the 2' bit, 3 is the wire corresponding to the 1 bit, 4 is the wire corresponding to the 23 bit, and 5" and 5" are the wires corresponding to the 23 bit. The wire corresponding to 24 bits is shown.

Therefore, the substrates A-A'' are formed so that they do not have the same area, and the conductor layer B-8'' is formed on each substrate by printing or etching, and the substrates having these conductor layers are As shown in FIG. 2, the substrates are laminated to form a diaphragm. In FIG. 0, only the substrates A and A' are shown.

Figure 3 shows a cross-sectional view of the diaphragm, and in the figure, C
is a yoke, D is a magnet, E is a diaphragm, and a conductor layer B is formed on a substrate A.

With the above configuration, if two diaphragms are laminated, the area of the finished diaphragm will be 1 of the total area of the conventional product.
/2. If three sheets are laminated, it will be 1/3.

This configuration not only reduces the area, but also
This has the effect of increasing the rigidity of the diaphragm and preventing the split vibration that tends to occur in this type of diaphragm.

Furthermore, according to the above structure, the magnetic circuit is also reduced in size in proportion to the area of the diaphragm, which has a significant effect on cost reduction.

In addition, when laminating the substrates, as shown in the example in Fig. 4,
The rigidity of the entire diaphragm can be balanced by laminating A2 in the opposite direction of the conductor layer pattern.

Furthermore, it goes without saying that the present invention is not limited to digital speakers and can be widely applied to conductive planar speakers.

(Effects of the Invention) As described above, according to the present invention, in a speaker having a wire ring made of conductive foil on a diaphragm, a plurality of diaphragms are weighted for each bit of a digital signal. 0) The area required for the moving plate can be reduced to at least 172 cm or less compared to the conventional one, and the structure of the magnetic circuit can be reduced accordingly. Therefore, the size of the speaker can be reduced.

(b) By laminating, the rigidity of the diaphragm can be increased, and it is possible to prevent the occurrence of split vibration that tends to occur in this type of diaphragm.

(c) Furthermore, by selecting the direction of the pattern of the conductor layer formed on the substrate, it is also possible to balance the rigidity of the diaphragm.

It has the following effects.

[Brief explanation of the drawing]

FIG. 1 shows the diaphragm in the speaker of the present invention, and the second
The figure shows a stacked state, FIG. 3 is a sectional view of the speaker, and FIG. 4 shows another example of stacking. A-A"...Substrate B-B"...Conductor layer C...
・Yoke D...Magnet E...Diaphragm Patent Applicant Foster Electric Co., Ltd. Agent Patent Attorney Michio Takayama (1 other person) Figure 1 Figure 2 Figure 3 Date

Claims (1)

[Claims] An electrodynamic speaker having a wire ring made of conductive foil on a diaphragm, characterized in that it is constructed by laminating a plurality of diaphragms weighted for each bit of a digital signal. Planar drive speaker.