JPH01101798A - Speaker - Google Patents

Abstract

PURPOSE:To obtain nondirectivity by arranging a diaphragm formed with a drive coil on the surface in a DC magnetic field formed by a superconduction magnet and supplying an electric signal to a drive coil so as to radiate sound in the circumferential direction. CONSTITUTION:A drive coil 19 formed on the surface of a diaphragm 18 is arranged in a DC magnetic field formed by a superconduction magnet 10 and a driving force proportional to an electric signal is generated by supplying the electric signal to the drive coil 19, the diaphragm 18 is vibrated to radiate sound. When the superconduction coil 11 is a solenoid coil where the superconductor is wound cylindrically especially, the DC magnetic field is uniform over the entire circumference and the uniform DC magnetic field is used to generate the drive force proportional to the electric signal in the circumferential direction to reproduce the sound. Moreover, since the diaphragm is vibrated radilly over the circumferential direction in a speaker whose diaphragm 18 is cylindrical, the sound is radiated in the circumferential direction to attain nondirectivity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a speaker using a superconducting magnet as a magnet for forming a direct current magnetic field. Concerning speakers that have achieved this goal.

[Prior Art] As shown in FIG. 3, an electrodynamic speaker is equipped with an external magnetic circuit 1, and a magnetic gap 2 of the magnetic circuit 1 is connected to the top of a sliding plate 4. The voice coil 5 is positioned, and the peripheral portion of the voice coil 5 and the diaphragm 4 are supported by a frame (not shown) to constitute a vibration system, and an electric signal is supplied to the voice coil 5. Has a structure. A permanent magnet is generally used as the DC magnetic field forming magnet of the magnetic circuit 1.

To address the problem of realizing omnidirectionality, for example, a speaker system having a structure in which a plurality of electrodynamic speakers are arranged in a polygonal shape is known.

In addition, for the same problem, two or more disc-shaped piezoelectric elements 6.7 are arranged at a predetermined interval as shown in FIG. It is known that a cylindrical diaphragm 8 provided with corrugations 9 in the circumferential direction is attached, and the cylindrical diaphragm 8 is moved in the radial direction by deforming the disc-shaped piezoelectric element 6.7 in the radial direction. be.

[Problems to be Solved by the Invention] Since the electrodynamic speaker uses a method for forming a direct current magnetic field to avoid concentration of magnetic flux in the magnetic gap 2, the diaphragm 4 can only be driven in one direction (back and forth). Therefore, acoustic radiation is only unidirectional, and omnidirectionality cannot be achieved. In addition, in order to make the magnetic energy of the magnetic circuit 1 strong, it is necessary to make the permanent magnet large or, if an electromagnet is used as a magnet for forming a DC magnetic field, to apply a large current to this electromagnet. Since it has to be flushed away, it becomes difficult to take measures against the heat generation.

In addition, with respect to the issue of achieving omnidirectionality, in the former speaker system with a structure in which multiple electrodynamic speakers are arranged in a polygonal shape, acoustic radiation is discontinuous in the circumferential direction, and multiple electrodynamic speakers are arranged in a polygonal manner. Electric type speakers are required, and as many magnetic circuits and vibration systems are required. Furthermore, in this type of speaker system, even if a leaf type speaker called a full-plane drive type is used instead of an electrodynamic type speaker, the DC magnetic field is not uniform, in addition to the same problem as above. Therefore, it is inferior in terms of acoustic characteristics such as distortion characteristics.

In the latter speaker, in which a cylindrical diaphragm 8 with corrugations 9 provided in the circumferential direction is attached to the outer periphery of a disc-shaped piezoelectric element 6.7, the piezoelectric element 6.7 cannot maintain an amplitude, so the sound pressure is low, making it unsuitable for reproducing low-frequency sounds. If an attempt was made to reproduce low-frequency sound, a piezoelectric element with a very large area would be required, which would be impractical. Furthermore, since this type utilizes the resonance of a piezoelectric element, it is difficult to achieve flat sound pressure frequency characteristics.

[Means for Solving the Problems] Referring to FIGS. 1 and 2 showing typical embodiments of the present invention, the following will be explained: (1) A superconducting magnet (10) is provided, 10) An imaging plate (18) having a drive coil (19) formed on its surface is disposed in the DC magnetic field formed by 10), and an electric signal is supplied to the drive coil (19). .

(2) The diaphragm (18) is shaped like a flat plate.

■ The superconducting magnet (10) has a built-in cylindrical superconducting coil (11), and the diaphragm (18) is arranged opposite to the cylindrical surface of the superconducting coil (11). .

(2) The superconducting magnet (10) has a cylindrical outer wall surface, and the diaphragm (18) has a cylindrical shape.

(2) A feature is that corrugations (20) are formed along the cylindrical surface of the diaphragm (18).

(2) The diaphragm (18) is film-shaped.

(2) The driving coil (19) is a printed coil formed on the surface of the diaphragm (18).

[Function] In particular, the characteristics are as follows: (1) Since the drive coil 19 formed on the surface of the diaphragm 18 is placed in the DC magnetic field formed by the superconducting magnet 10, the drive coil 19 By supplying an electrical signal, a driving force proportional to the electrical signal is generated, which causes the diaphragm 18 to vibrate and emit sound.

■ In particular, when the superconducting coil 11 is a solenoid type in which a superconductor is wound into a cylindrical shape, the DC magnetic field is uniform over the entire circumference, and this uniform DC magnetic field is used to generate a driving force proportional to the electric signal. is generated all around the circumference,
Sound can be played back.

Further, in a speaker in which the diaphragm 18 has a cylindrical shape, the diaphragm vibrates in the radial direction over the entire circumference, so that sound is radiated in the entire circumference, resulting in non-directionality.

[Example] The following 11 representative examples of the present invention are shown in Figures 1 and 2.
This will be explained in the figure.

Reference numeral 10 denotes a superconducting magnet having a cylindrical outer shape and a cylindrical outer wall surface, a superconducting coil 11 made of a superconductor wound into a cylindrical shape, and a superconducting coil 11 housed in the superconducting critical magnet. It is composed of a first storage body 12 that maintains the temperature below a predetermined temperature and a second storage body 13 that houses the first storage body 12 and maintains the temperature below a predetermined temperature.

The first container 12 contains liquid helium with a boiling point of -263°C, and the second container 13 contains:
Liquid nitrogen with a boiling point of -196°C is contained.

Note that if a superconductor with a high temperature far exceeding absolute zero is used, the first and second storage bodies 12.13
The cooling substance to be added to the tank should be one with a high boiling point. Moreover, in this case, the first storage body 12 or the second storage body 13 is not necessary depending on the type of high-temperature superconductor.

Reference numeral 14 denotes a circular upper plate, on the outer periphery of which is formed a ring-shaped protrusion 14a that protrudes downward.

Reference numeral 15 denotes a lower plate integrally provided with a center ball portion 16 in the center to be inserted into the inside of the superconducting magnet 10, and a ring-shaped protrusion portion 1 projecting upward on the outer periphery of the lower plate.
5a is formed. The protruding portion 15a faces the protruding portion 14a of the upper plate 14.

A magnetic circuit is formed by the superconducting magnet 10, the upper plate 14 and the lower plate 15, and
Both convex stripes 14a of the upper plate 14 and lower plate 15
, 15a, a DC magnetic field is formed between them.

Since the superconducting coil 11 that forms the DC magnetic field is a solenoid type in which a superconductor is wound into a cylindrical shape, the magnetic flux uniformly spreads from one pole of the superconducting coil 11 in the entire circumferential direction, and spreads to the other pole. It converges and becomes uniform over the entire circumference.

Therefore, the upper plate 14 and the lower plate 15
The DC magnetic field formed between both convex stripes 14a and 15a is
It becomes uniform over the entire circumference.

An elastic cylindrical support 17 made of maltbrene or the like is attached to the outer wall surface of the superconducting magnet 10.

Note that this support 17 is cylindrical and does not need to be attached over the entire outer wall surface of the superconducting magnet 10; for example, a plurality of ring-shaped supports 17 are attached to the upper and lower ends of the outer wall surface of the superconducting magnet 10, It may also be attached to an appropriate location in the center if necessary.

A film-like cylindrical diaphragm 18 on which a drive coil 19 is formed is supported by the support 17 .

That is, this cylindrical diaphragm 18 is connected to the upper plate 1.
4. It is supported in a DC magnetic field formed between both protrusions 14a and 15a of the lower plate 15.

The cylindrical diaphragm 18 is manufactured by etching a copper foil formed on the surface of a rectangular film to form a plurality of drive coils 19, and then molding the film into a cylindrical shape. The drive coils 19 are connected in parallel or in series, and an electric signal (music signal) is supplied to both ends thereof.

Roughly speaking, the cylindrical diaphragm 18 has corrugations 20 formed along its cylindrical surface so that it vibrates uniformly in the radial direction.

Note that the diaphragm 1B does not necessarily have to be cylindrical, and may be, for example, semi-cylindrical, roughly flat, or rectangular with a cylindrical surface. Good too.

[Effects of the invention] ■ If the superconducting magnet 10 is necessarily a solenoid type, its DC magnetic field is uniform over the entire circumference in the circumferential direction, and this uniform DC magnetic field is used to generate a driving force proportional to the electric signal. Since the sound can be reproduced by changing the sound, acoustic characteristics such as distortion characteristics can be improved.

■ In speakers where the flat diaphragm 18 has a cylindrical shape, (because the diaphragm 18 vibrates in the radial direction over the entire circumference, the sound is radiated in the entire circumferential direction and becomes omnidirectional.

[Brief explanation of the drawing]

Fig. 1 shows the structure of a typical embodiment of the speaker of the present invention, Fig. 2 shows the structure of the diaphragm, and Figs. 3 and 4 show the structure of a conventional speaker. It is a diagram. 10...Superconducting magnet, 11...
Superconducting coil, 12...First storage body, 13.
...First storage body, 14... Upper plate, 15... Lower plate, 14a, 15a.
...Convex strip portion, 16...Center ball portion, 17...Support, ]8...Vibration plate,
19... Drive coil, 20... Corrugation. Patent applicant Onkyo Corporation 10...Superconducting magnet 11...Superconducting coil V12...First storage body 13...
...Second storage body 14,...Top plate'
15... Lower grate 16... Center ball part 17... Support body 18... Vibration plate
19...Drive coil 20...Corrugationer 1 Figure B

Claims (7)

[Claims] (1) Equipped with a superconducting magnet (10), a diaphragm (18) having a driving coil (19) formed on its surface is arranged in a DC magnetic field formed by the superconducting magnet (10), and the above-mentioned A speaker characterized in that an electric signal is supplied to a drive coil (19). (2) The speaker according to claim 1, wherein the diaphragm (18) has a flat plate shape. (3) The superconducting magnet (10) includes a cylindrical superconducting coil (11), and the diaphragm (18) is arranged opposite to the cylindrical surface of the superconducting coil (11). A speaker according to claim 1. (4) The speaker according to claim 1, wherein the outer wall surface of the superconducting magnet (10) is cylindrical, and the diaphragm (18) is cylindrical. (5) The speaker according to claim 4, characterized in that an uneven corrugation (20) is formed along the cylindrical surface of the diaphragm (18). (6) Claims 1, 2, 3, and 4 characterized in that the diaphragm (18) is film-shaped.
The speaker described in paragraph or paragraph 5. (7) The speaker according to claim 6, wherein the drive coil (19) is a printed coil formed on the surface of the diaphragm (18).