JPH0733518Y2 - Speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a speaker in which a diaphragm that emits sound waves is vibrated by a driving voice coil.

[Conventional technology]

As shown in FIG. 4, in this type of conventional speaker, when a voice signal current flows through a driving voice coil 41 wound around a coil bobbin 37, a top plate 31 and a magnet 3 are provided.
2, and a bottom plate 33 with a center pole 34
The coil bobbin 37 vibrates by the electromagnetic induction action of the magnetic circuit consisting of the above and the driving voice coil 41, and this vibration is transmitted to the diaphragm 36, and sound waves are emitted from the diaphragm 36.

In the above speaker, when an excessive voice signal current flows through the driving voice coil 41, the amplitude of vibration of the driving voice coil 41 generated by Fleming's left-hand rule increases, and the driving voice coil 41 is driven by the above-mentioned magnetic circuit. The coil 41 protrudes and free vibration is generated in the diaphragm 36. Therefore, harmonic distortion occurs in the sound wave generated by the diaphragm 36, which leads to the assumption of sound quality.

Therefore, in the conventional speaker, the above problem is dealt with by increasing the winding length of the driving voice coil 41, by hardening the damper 38, or by strengthening the magnetism of the magnet 32 in addition to these. ing.

[Problems to be solved by the device]

However, in the structure in which the winding length of the driving voice coil 41 is long, although the vibration amplitude of the driving voice coil 41 is limited, the mass of the vibration system increases, resulting in a decrease in efficiency and a deterioration in sound quality. Also, even if the damper 38 is made hard,
This leads to a decrease in efficiency. On the other hand, in the structure in which the magnetic force of the magnet 32 is strengthened in addition to the above-mentioned processing, the efficiency and the deterioration of the sound quality can be avoided, but there is a problem that the cost is increased.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the speaker according to the present invention vibrates the coil bobbin due to the electromagnetic induction action of the driving voice coil and the magnetic circuit when a signal current flows through the driving voice coil wound around the coil bobbin. In a speaker in which sound waves are emitted from the diaphragm by transmitting this vibration to the diaphragm, a pair of braking voice coils are connected in series to the driving voice coil and the driving voice coil is connected to the coil bobbin. The coil and the winding direction are wound in opposite directions, and are set at predetermined intervals from both ends of the driving voice coil so that they can be displaced in the magnetic field of the magnetic circuit when the signal current has a large amplitude. ing.

[Action]

According to the above configuration, since a pair of braking voice coils, which are connected in series with the driving voice coil and have a winding direction opposite to that of the driving voice coil, are wound around the coil bobbins, respectively. The direction of the force that drives the coil bobbin by the magnetic circuit and the magnetic circuit is opposite to the direction of the force that drives the coil bobbin by the driving voice coil and the magnetic circuit.

The braking voice coils are set at predetermined intervals from both ends of the driving voice coil so that they can be displaced into the magnetic field of the magnetic circuit when the signal current has a large amplitude.

Therefore, when a large-amplitude signal current such as an excessive voice flows in the driving voice coil, each braking voice coil that is not under the influence of the magnetic field of the magnetic circuit at the amplitude of the normal voice coil is connected to the voice coil. A large amplitude, that is, a large displacement makes it possible to move the magnetic field into the magnetic field under the influence of the magnetic field.

As a result, it is possible to suppress the transient phenomenon of the vibration of the coil bobbin at the time of a large amplitude by the electromagnetic induction action of each braking voice coil which is in the opposite direction to the force of the magnetic field induction action by the driving voice coil. The protruding voice coil can be avoided.

As a result, in the above configuration, by only providing each braking voice coil that does not significantly increase the vibration system mass including the coil bobbin and the diaphragm, the driving voice coil caused by the protrusion of the driving voice coil from the magnetic circuit is provided. It is possible to reduce the free vibration of, and it is possible to prevent the deterioration of the sound quality from the diaphragm due to the free vibration.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

The speaker according to the present invention has a magnetic circuit 20 on its back, as shown in FIG. This magnetic circuit 20 has an opening 1a.
Is provided between the top plate 1 and the bottom plate 3, and a disc-shaped top plate 1 having a disc-shaped top plate 1, a column-shaped center pole 4 standing at the center, and a disc-shaped bottom plate 3. The pole 4 is composed of an annular magnet 2 arranged so as to surround the outer periphery of the pole 4 at a predetermined interval, and these members are integrally connected.

On the front end surface of the top plate 1, an inner peripheral end portion side of a frame 9 for protecting each constituent member inside the speaker is attached. An edge supporting portion 9a having an annular flat surface shape is formed on the outer peripheral end side of the frame 9, and is connected to the outer peripheral portion of the cone-shaped diaphragm 6. Diaphragm 6
The inner peripheral portion of the coil bobbin 7 is connected to the outer peripheral portion on the front end side of the coil bobbin 7, and the coil bobbin 7 is suspended by the diaphragm 6 so that the coil bobbin 7 can vibrate back and forth.

The front end opening of the coil bobbin 7 has a center cap 5
It is blocked by. The rear part of the coil bobbin 7 is located in the gap formed between the center pole 4 and the top plate 1, and the driving voice coil 11 is wound around the rear part of the coil bobbin 7.

Further, the driving voice coil 11 in the coil bobbin 7
A voice coil 12 for braking is wound on both sides of the. As shown in FIG. 2, the braking voice coils 12 and 12 have opposite winding directions to the driving voice coil 11 and are connected in series with the driving voice coil 11.

Also, the voice coil 12 for braking is a voice coil for driving.
It is provided at a predetermined distance from the coil 11, and the maximum amplitude of the driving voice coil 11 is determined by this inter-coil distance. Further, the above inter-coil distance is set within a range in which the braking voice coils 12, 12 can exert their braking function in the magnetic field between the top plate 1 and the center pole 4.

In the above configuration, when a voice signal current flows through the driving voice coil 11, the driving voice coil 11 and the magnetic circuit 20
The coil bobbin 7 vibrates due to the electromagnetic induction action of, and this vibration is transmitted to the diaphragm 6, and sound waves are emitted from the diaphragm 6.

Here, when an excessive audio signal current flows through the driving voice coil 11, the amplitude of vibration of the driving voice coil 11 increases, but at this time, the electromagnetic waves of the braking voice coils 12 and 12 and the magnetic circuit 20 are increased. Drive voice coil by inductive action
A force to suppress the vibration of 11 is applied. This prevents the drive voice coil 11 from protruding from the magnetic circuit 20, and avoids free vibration of the drive voice coil 11. Therefore, the harmonic distortion of the voice waveform due to this free vibration is reduced, and the sound quality at the time of large input is improved.

Next, when the output waveforms of the speaker of the present invention having the braking voice coil 12 and the conventional speaker having no braking voice coil 12 were compared, the results shown in FIG. 3 were obtained. According to the figure, with respect to the signal waveform A of the input voice, in the output waveform B of the conventional speaker without the braking voice coil 12, the harmonic distortion component b caused by the free vibration of the driving voice coil becomes large. ing. On the other hand, in the output waveform C of the present speaker having the braking voice coil 12, the harmonic distortion component c is greatly reduced. At this time, the odd-numbered harmonic components are reduced in particular, so that the sound is not offensive to the ears.

[Effect of device]

As described above, in the speaker according to the present invention, the pair of braking voice coils are connected in series with the driving voice coil on the coil bobbin that transmits the vibration to the diaphragm and around which the driving voice coil is wound, and The coil is wound in a direction opposite to that of the driving voice coil, and the driving is performed so that the signal current for driving the driving voice coil can be displaced in the magnetic field of the magnetic circuit when the amplitude is large. The configuration is such that the voice coils are set at predetermined intervals from both ends of the voice coil.

With this configuration, the above-described configuration allows each of the braking voice coils through which the signal current flowing in the driving voice coil similarly flows so that the winding direction thereof is opposite to the winding direction of the driving voice coil. Since the braking voice coils are provided at a predetermined distance from the voice coil, the movement of the coil bobbin is braked only when the coil bobbin driven by the driving voice coil has an excessive amplitude. Thus, the free vibration of the coil bobbin can be suppressed.

By the way, in the related art, when the winding length of the driving voice coil is lengthened in order to limit the excessive amplitude of the vibration of the driving voice coil, the vibration system mass increases to lower the efficiency and deteriorate the sound quality. , If the damper is hardened,
There has been a problem that the efficiency is lowered, and further, when the magnetic force of the magnet is strengthened, the efficiency is lowered and the sound quality is deteriorated, but the cost is increased.

However, in the above configuration, since it is possible to suppress the occurrence of harmonic distortion due to the free vibration of the driving voice coil, only by providing each braking voice coil on the coil bobbin, which does not cause a large increase in the vibration system mass, the above-mentioned conventional The effect that the sound quality of the sound from the diaphragm can be improved while avoiding each problem.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a half sectional view showing a speaker. FIG. 2 is a circuit diagram showing winding directions and connection states of the braking voice coil and the driving voice coil. FIG. 3 is a waveform diagram showing an audio signal waveform and output waveforms of the speaker without the braking voice coil and the speaker with the braking voice coil with respect to the audio signal waveform. FIG. 4 is a half sectional view showing a conventional speaker. 1 is a top plate, 2 is a magnet, 3 is a bottom plate, 4 is a center pole, 6 is a diaphragm, 7 is a coil bobbin, 11 is a driving voice coil, 12 is a braking voice coil, and 20 is a magnetic circuit.

Claims (1)

[Scope of utility model registration request] 1. When a signal current flows through a driving voice coil wound around a coil bobbin, the coil bobbin vibrates due to an electromagnetic induction action of the driving voice coil and a magnetic circuit, and the vibration is transmitted to a diaphragm. In the speaker in which sound waves are emitted from the diaphragm by the coil bobbin, a pair of braking voice coils are provided.
It is connected in series with the driving voice coil, is wound in the opposite winding direction to the driving voice coil, and is displaced in the magnetic field of the magnetic circuit when the signal current has a large amplitude. A speaker characterized in that it is set at predetermined intervals from both ends of the driving voice coil.