JPS6253099A - Rotary type speaker - Google Patents

Abstract

PURPOSE:To efficiently generate a large sound output by providing a propeller type fan to emit sound waves by its oscillating rotation, and letting the fan rotate the oscillating rotation by an electromagnetic force generated by an A.C. electrical signal corresponding to a sound. CONSTITUTION:A permanent magnet is a stator, and a sheet coil is a rotor, and the fan connected integrally with the sheet coil is made rotate as oscillating. That is the A.C. electrical signal corresponding to a sound i.e. so called a sound current, is supplied to the armature coil of the sheet coil 14, and then, an electromagnetic rotational torque is generated by the electromagnetic interaction of the sound current and the magnetic flux from the permanent magnet 16, causing the fan 10 on the rotor-side rotate integrally with the sheet coil 14. Because the direction of flowing of the sound current changes with comparatively short period corresponding to the waveform of the sound wave, the fan 10 oscillatingly rotates, and sends a sound wave or a sound pressure forward.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention transmits high-output plane sound waves with high efficiency and
The present invention relates to a thin speaker with a novel structure that enables high-fidelity reproduction sound.

(Prior Art) Conventional speakers have various operating systems, such as a dynamic type and a capacitor type, but all of these systems excite a diaphragm to emit sound waves.

FIG. 2 shows an example of a planar speaker that has recently attracted attention. In this figure, a disk-shaped planar diaphragm 1 is made of, for example, a honeycomb sandwich composite material with low density and very high rigidity. One end of a cylindrical bobbin/2 is connected to the nodal circle of the plane diaphragm 1, and a voice coil 3 is wound around the outer periphery of the bobbin 2. A constant magnetic field is applied to the voice coil 3 in the radial direction by a permanent magnet (not shown).

In a speaker having such a structure, sound is generated in the following manner. That is, when an electrical signal representing a sound, a so-called sound current, is supplied to the voice coil 3, the voice coil 3 vibrates in the directions of arrows AO and AI due to the interaction between the sound current and the magnetic field, thereby causing the plane diaphragm to vibrate. l also vibrates in the same direction, and a conch wave-shaped sound wave corresponding to the sound current is emitted.

(Problem to be Solved by the Invention) In a speaker like the one described above, the diaphragm is driven at the nodal position in order to reduce sound distortion, but the nodal circle is theoretically 0.68Ra ( Since Ra is given as the radius of the nodal circle, the diameters of the bobbin 2 and the voice coil 3 are relatively large, and therefore the weight of the vibration system becomes large, resulting in a problem of large power consumption. In addition, standing waves are generated between the diaphragm 1 and the inner wall of the cabinet facing it, and sound waves are also radiated to the back side of the diaphragm 1, but the structure of the back side is complex, so it is easily affected by high-order division. There is a problem in that Hi-Fi reproduced sound cannot be produced due to factors such as high Q during resonance in vibration. In addition, since conventional cone-shaped speakers are generally provided with a damper to appropriately damp the vibration of the voice coil, there is also the problem that the efficiency decreases due to the corresponding loss.

The present invention has been made in view of the above-mentioned problems of the prior art.
The purpose of the present invention is to provide a thin speaker capable of producing i-like reproduced sound.

(Means for Solving the Problems) The configuration of the present invention that achieves the above object uses a propeller-shaped fan that emits sound waves by rocking and rotating, and an electromagnetic force generated by an AC electric signal corresponding to sound. The present invention is characterized by comprising an oscillating rotation drive means for oscillatingly rotating the propeller type fan.

(Function) When an alternating current electric signal corresponding to the sound is supplied to the oscillating rotation drive means, an electromagnetic force is generated to change the direction, and the propeller type fan oscillates and radiates sound pressure or sound waves forward. Compared to methods that generate sound pressure through vibration, this method of generating sound pressure through the oscillating rotation of the fan is more efficient and produces a larger output because it uses rotational force, and it also produces sound only in the front. (because it sends out pressure) li-Fi
You can get a good playback sound.

(Embodiment) FIG. 1 shows a rotary type speaker according to an embodiment of the present invention. In this figure, a propeller-shaped fan 10 is made of a light metal such as titanium or aluminum and is radially attached to a rotating shaft 12.

A rotor consisting of a sheet coil 14 is fixed to the lower side of the fan 10. This sheet coil 14 has a well-known structure, and is formed by processing a printed circuit board using photorenost to form fan-shaped armature coil patterns arranged in the circumferential direction.

A stator made of permanent magnets 16 is disposed below the coil 14 and facing each other with a small gap g interposed therebetween. These permanent magnets 16 have the same number of poles as the sheet coil 14, and are arranged in a donut shape on a circumference concentric with the rotating shaft 12. Each permanent magnet 16 is magnetized in the direction of the rotation axis, and the magnetic flux generated therefrom interlinks with the armature coil of the sheet coil 14 at right angles. A bearing 18 that supports the rotating shaft 12 is provided in the central opening of the permanent magnet 16 .

The rotary type speaker of this embodiment configured in this manner operates as a type of flat motor.

However, whereas in a general flat motor, the permanent magnet is the rotor and the sheet fill is the stator, in the rotary type speaker of this example, the permanent magnet is the stator, the sheet coil is the rotor, and the /-to coil is integrated with the rotary type speaker. The feature is that the combined fan 10 swings and rotates.

That is, when an alternating current electric signal corresponding to a sound, a so-called sound current, is supplied to the armature coil of the sheet coil 14, the rotational torque of the electromagnetic force is increased due to the electromagnetic interaction between the sound current and the magnetic flux from the permanent magnet 16. The fan 10 on the rotor side rotates integrally with the sheet coil 14. Since the direction in which the audio current flows changes in a relatively short period according to the audio waveform, the fan 10 rotates in an oscillating manner (does not rotate widely, but rotates back and forth finely depending on the AC signal), thereby forwarding the sound waves or sound pressure. Send.

As described above, in this embodiment, the sheet coil 14 and the permanent magnet 16 constitute a flat motor type oscillating rotation driving means, and the sheet coil 14 as a rotor is integrated with the note coil 14 by supplying an audio current to the sheet coil 14. A propeller-shaped fan 10 coupled to each other is rocked and rotated, thereby sending out sound waves forward.

In addition, the permanent magnet 1 is attached via a suitable support plate such as a disc-shaped plate.
6 and the fan 10 may be integrally combined, in which case the permanent magnet 16 may be arranged above as a rotor, and the note coil 14 may be arranged below the stator.

(Effects of the Invention) As described above, in the present invention, since the propeller type fan is oscillated and rotated to radiate sound waves, compared to the conventional method in which the diaphragm is vibrated to radiate sound waves. , (1
(2) High-output audio can be generated efficiently; (3) Sound waves are generally sent out as plane waves only in front of the fan, and only a small amount is sent out behind the cabinet. If you can suppress the standing waves inside, there will be no influence of the structure on the back side on the upper side, and there will be no problem of split vibration, which has the advantage of producing Hi-Fl +rT raw sound.

[Brief explanation of the drawing]

FIG. 1 shows rotor IJ l+, l according to an embodiment of the present invention.
1 is a cross-sectional view showing the structure of a speaker, and FIG. 2 is a smaller cross-sectional view of the structure of a conventional back-rear speaker. 10...Propeller type F/, 12 river co-rotating shaft, 14.
...sheet coil, 16-track permanent magnet, 18...bearing,
g... Gap.

Claims (2)

[Claims] (1) A propeller-shaped fan that radiates sound waves by rotating in an oscillating manner, and a oscillating rotation drive means that oscillates and rotates the propeller-shaped fan using electromagnetic force generated by an AC electric signal corresponding to sound. A rotary type speaker characterized by: (2) The rocking rotation driving means includes a sheet coil integrally coupled with the propeller-shaped fan, and a permanent magnet magnetized in the direction of the rotation axis and facing the sheet coil at a small distance. The rotary type speaker according to claim 1, comprising a magnet.