JPS62115995A - Speaker unit - Google Patents

Abstract

PURPOSE:To remove the distortion of a reproducing signal and to detect a correct MFB signal by providing a reinforcing bridge on a diaphragm and increasing the strength of the diaphragm. CONSTITUTION:In a speaker unit in which the diaphragm 5 consists of a plane diaphragm, the diaphragm 5 is provided with the reinforcing bridge 11 to increase the strength of the diaphragm 5. When this rigidity is increased, a division vibration is not generated to a high frequency area but follows the movement of a voice coil 3, and a piston band P extends to the high frequency area. If the oscilation of the diaphragm 5, a signal detected by a piezoelectric sensor 10 becomes a highly accurate signal completely controlled by the voice coil 3 to the high frequency area. Thereby, the reproducing sound having no high frequency area distortion is obtained. When the vibration of the diaphragm 5 is detected, the detecting accuracy is improved, a circuit constitution is simplified and the stability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a speaker unit using a plane diaphragm suitable for use in, for example, a motional feedback speaker unit.

[Summary of the invention]

The present invention uses a planar diaphragm suitable for use in, for example, a motional feedback type speaker unit, and in a nine-speaker unit, the diaphragm is provided with a reinforcing Grino-Zo to increase the strength of the diaphragm. The movement of the diaphragm now follows the movement of the disc coil up to the high range without splitting vibrations, providing distortion-free reproduction sound up to the high range, and improving detection accuracy when detecting vibration of the diaphragm. The circuit configuration can be simplified and stability can be improved.

[Conventional technology]

Conventionally, motional feedback (hereinafter M
A speaker unit of the FB type has been developed. For example, the third
It is configured as shown in the figure. The speaker unit shown in FIG. 3 is a so-called flat speaker unit using a flat diaphragm. In the figure (1) indicates a yoke, a magnet (2) is arranged around this yoke (1), a discoil (3) wound around a bobbin (3a) is arranged in the center, and this voice coil (3) is arranged around the yoke (1). ) coupler (4)
It is connected to the plane diaphragm (5) via. This planar diaphragm (5) is made of a so-called "no-nikum" structure plate, which is made by bonding aluminum plates (sb) to the top and bottom of a honeycomb-shaped core (5a), for example. In addition, the magnet (the plate above 2 inches)
At the tip of the frame (7) fixed to the edge (8)
) to support the plane diaphragm (5) through the diaphragm (9).
> connects the bobbin (3a) and frame (7). For example, a piezoelectric sensor αQ, which is a component for MFB, is mounted on the lower or upper surface of the central part of the flat diaphragm (5).
Install. With this configuration, the piezoelectric element on the piezoelectric sensor αQ detects the movement of the diaphragm (5), and the FiiFB signal is obtained in response to this detection. The MFB signal from this piezoelectric sensor αQ is fed back to the front stage of an output amplifier (not shown) to control the vibration of the diaphragm (5) and improve transient characteristics and distortion.

[Problem that the invention seeks to solve]

However, in a flat speaker unit using a flat diaphragm configured as described above, when the vibration of the diaphragm (5) exceeds a specific frequency, split vibration occurs, and the high frequency range exceeding this specific frequency is generated. This results in increased distortion.

That is, what about the diaphragm (5) as shown in Figure 4? Iskoil (
3) The downward movement (A direction) causes the central part to move upward (A' direction), and the upward movement (B direction) of the disc coil (3) causes the central part to move downward (B' direction). However, when the voice coil (3) moves faster, the diaphragm (5) does not completely follow the movement, causing different vibrations between the area connected to the coupler (4) and the area near the center. Figure 5 shows an example of this frequency characteristic.The reproduction frequency is stable up to a certain frequency, the so-called piston band P, but beyond this certain frequency, the characteristics of the diaphragm become unstable. Therefore, the instability of this characteristic appears as distortion in the high-frequency reproduced sound.

In addition, the diaphragm (5) extends beyond the piston zone P in this way.
When the diaphragm (5) starts to vibrate in divided vibrations, in the case of the MFB type speaker unit as described above, even if the piezoelectric sensor α1 detects the vibration of the diaphragm (5), the diaphragm (5) If the rounding does not completely follow the control by MFB, accurate detection of the MFB signal will no longer be possible. For this reason, the conventional MF'B type speaker unit is
It is necessary to take some measures on the side of the circuit that processes the FB signal, which inconveniently increases the complexity of the circuit configuration and increases the manufacturing cost.

In view of these points, it is an object of the present invention to provide a speaker unit that can reduce split vibration of a diaphragm in high frequencies, reduce distortion of a reproduced signal, and accurately detect an MFB signal.

[Means for solving problems]

In the speaker unit of the present invention, for example, as shown in FIG. 1, in a speaker unit in which the diaphragm (5) is a flat diaphragm, a reinforcing bridge circle is provided on the diaphragm (5), It has increased strength.

[Effect]

By providing the reinforcing bridge aυ, the speaker unit of the present invention prevents the movement of the diaphragm (5) from discoil (3).
The movement of the diaphragm (5
), the detection accuracy is improved, the circuit configuration can be simplified, and the stability is improved.

〔Example〕

An embodiment of the speaker unit of the present invention will be described below with reference to FIGS. 1 and 2. In FIGS. 1 and 2, parts corresponding to those in FIGS. 3 to 5 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

As shown in FIGS. 1 and 2, the speaker unit of this example has a reinforcing bridge αυ provided on the coupler (4) side of a planar diaphragm (5) made of a honeycomb structure plate.

This reinforcing bridge αυ is made of an aluminum plate, for example, and fits inside the cassilla (4), and its end face (l1m) abuts the lower aluminum plate (5b) of the flat diaphragm (5), and this cassilla (4) and Fix it to the lower aluminum plate (5b) with adhesive or the like. The rest of the structure is the same as that of the speaker unit shown in FIG. 3.

The speaker unit of this example has a reinforced bridge α as described above.
By providing η, the rigidity of the plane diaphragm (5) increases. When this rigidity increases, split vibrations no longer occur in the high range, and the piston zone P shown in FIG. 5 extends to the high range. This rounding narrows the band where distortion occurs in the reproduced sound,
You can get good reproduction sound with no distortion up to the high frequencies. Also,
The piston band P extends to the high range and the vibration of the diaphragm (5) follows the disc coil (3) to the high range, resulting in MFB.
When detecting the vibration of the diaphragm (5) as in the speaker unit of the above-mentioned method, the signal detected by the piezoelectric sensor αQ becomes a highly accurate signal that completely follows the control by the disc coil (3) up to the high frequency range. . For this reason, for example, in the case of the MFB method, it is possible to accurately detect the MFB signal up to the high frequency range, improving stability and eliminating the need to deal with signal deviations on the circuit side that processes the MF'B signal. can be simplified and manufacturing costs can be reduced.

In the above embodiment, only one reinforcing bridge αη was provided, but it is also possible to provide a plurality of reinforcing bridges, and in this case, various arrangements such as orthogonal arrangement of the two reinforcing bridges in a cross shape are possible. In the case of , the same action and effect as described above can be obtained. Furthermore, it goes without saying that the present invention is not limited to the above-described embodiments, and can take various other configurations without departing from the gist of the present invention.

〔Effect of the invention〕

According to the speaker unit of the present invention, by providing the reinforcing bridge α, the movement of the diaphragm (5) follows the movement of the disc coil (3) up to the high range without splitting vibration, and even up to the high range. Distortion-free reproduced sound can be obtained, and when detecting vibrations of the diaphragm (5), detection accuracy is improved, the circuit configuration can be simplified, and stability is improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the speaker unit of the present invention, Fig. 2 is a perspective view showing the main parts of the example shown in Fig. 1, and Fig. 3 is a sectional view showing an example of a conventional speaker unit. , 4th
The figure is a diagram showing the movement of the diaphragm and the disc coil, and FIG. 5 is a diagram showing the frequency characteristics. (5) is a thousand-sided damage plate, and 9M is a reinforced bridge.

Claims (1)

[Scope of Claims] A speaker unit whose diaphragm is a flat diaphragm, characterized in that the diaphragm is provided with a reinforcing bridge to increase the strength of the diaphragm.