JP2621348B2 - Speaker - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker, and more particularly to simplification of a network circuit.

[Summary of the Invention]

The present invention includes a diaphragm provided with an annular conductive portion, a power supply coil disposed to face the conductive portion with a predetermined gap, and a magnetic circuit to which the power supply coil is attached. By connecting a capacitor that constitutes a high-pass filter together with a resistor in series with the power supply coil, the network circuit can be simplified, for example, when used as a high-frequency speaker.

[Conventional technology]

In some cases, the reproduction band of the speaker is divided into, for example, a low band and a high band, and low- and wide-range speakers suitable for the respective reproduction bands are selected, and these are combined to constitute a speaker system. In such a case, in order to set the reproduction band of each speaker, a network circuit is provided in all stages of each speaker.

For example, as shown in FIG. 7, it is assumed that a speaker system is composed of a high-range speaker 51 and a low-range speaker 52. In this case, a network circuit 53 is connected between the output amplifier 54 and the high-range speaker 51 and the low-range speaker 52. The network circuit 53 includes high-pass filters 55A and 55B.
And a low-pass filter 56, and a high-frequency speaker 51
, High-pass filters 55A and 55B are arranged before the low-frequency speaker 52, and a low-pass filter 56 is arranged before the low-frequency speaker 52.

When a speaker system is configured using a plurality of speakers as described above, it is necessary to sharpen the characteristics of the network circuit 53 in order to eliminate interference between speakers in each band. However, when a speaker system is configured with a conventional dynamic speaker, if the characteristics of the network circuit are to be made steep, there is a problem that the network circuit is complicated.

For example, in FIG. 7, it is assumed that the characteristics of the high-pass filter at the preceding stage of the high frequency speaker 51 are to be set to a steep characteristic of 12 dB / oct. When a conventional dynamic type speaker is used as the high-frequency speaker 51, at this time, as shown in FIG. 7, for example, a high-pass filter 55A of 6 dB / oct and a 6 dB / oct
It is necessary to cascade connect the oct high-pass filter 55B.

[Problems to be solved by the invention]

Thus, in the conventional dynamic speaker,
In a case where a speaker system is configured using a plurality of speakers, if the characteristics of the network circuit are to be made steep, there is a problem that the network circuit is complicated.

Accordingly, an object of the present invention is to provide a speaker that can simplify a network circuit when a speaker system is configured using a plurality of speakers.

[Means for solving the problem]

The present invention relates to a diaphragm 6 provided with an annular conductive portion 17.
A power supply coil 15 disposed opposite the conductive portion 17 with a predetermined gap; and a magnetic circuit to which the power supply coil 15 is attached. The speaker is characterized in that it is connected in series to the feeding coil 15.

[Action]

When a speaker system is configured by a plurality of speakers, an inductive speaker is used as the high-frequency speaker 1. The input side of the inductive type high frequency speaker is a feeding coil
A high-pass filter is equivalently composed of 15 inductances L and its internal resistance R. Therefore, when a capacitor is connected to the input terminal of the induction type high frequency speaker 1,
This is equivalent to two high-pass filters connected in cascade. That is, by connecting a capacitor to the input terminal of the inductive type high frequency speaker 1, a high-pass filter having steep characteristics can be configured, and a network circuit can be simplified when a speaker system is configured by a plurality of speakers.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a speaker system to which the present invention is applied. In FIG. 1, reference numeral 1 denotes a high frequency speaker, and 2 denotes a low frequency speaker. A speaker system is composed of the high-frequency speaker 1 and the low-frequency speaker 2. As the high-frequency speaker 1, an inductive speaker described in detail below is used. A dynamic speaker is used as the low-frequency speaker 2. An inductive speaker may be used as the low-frequency speaker 2.

A network circuit 3 is connected between the output amplifier 4 and the high-frequency speaker 1 and the low-frequency speaker 2. The network circuit 3 includes a capacitor 5 and a low-pass filter 6. A capacitor 5 is arranged before the high-frequency speaker 1, and a low-pass filter 6 is arranged before the low-frequency speaker 2.

The high frequency speaker 1 is an induction type speaker, and the high frequency speaker 1 is configured as shown in FIG.

In FIG. 2, a columnar pole piece 12 is formed at the center of a disk-shaped yoke plate 11. On this yoke plate 11, the magnet 13 on the ring is laminated,
It is fixed. The top plate 14 on the ring is laminated on the magnet 13 and fixed. These yoke plates 1
An outer magnet type magnetic circuit is constituted by the pole piece 12 and the magnet 13. A power supply coil 15 is wound around the inner periphery of the top plate 14. From the feeding coil 15, lead wires 19A and 19B are led out.

The diaphragm 16 is integrally formed of, for example, aluminum or the like. A conductive portion 17 is formed at an opening edge of the diaphragm 16. The conductive part 17 operates as a one-turn voice coil. Note that the diaphragm 16 may be formed from a non-conductor such as a polymer film or ceramics, and a conductor may be provided in the conductive portion 17.

A magnetic gap is formed in a gap where the outer periphery of the pole piece 12 and the inner periphery of the top plate 14 face each other, and the conductive portion 17 formed on the diaphragm 16 is inserted into the magnetic gap.
The diaphragm 16 is supported via a damper 18 so as to be freely vibrated.

The induction type high frequency speaker 1 has lead wires 19A and 19B.
It is driven by supplying an audio signal to the terminals 20A and 20B. That is, audio current flows from the terminals 20A and 20B to the power supply coil 15 via the lead wires 19A and 19B. Due to this audio current, a magnetic flux is generated in the feeding coil 15. This magnetic flux intersects with the conductive portion 17 arranged opposite to the feeding coil 15. As a result, an induced current flows through the conductive portion 17. Since the conductive portion 17 is located in the magnetic gap between the outer periphery of the pole piece 12 and the inner periphery of the top plate 14, when an induced current flows through the conductive portion 17, the force for moving the conductive portion 17 is obtained. Is generated. The diaphragm 16 is driven by this force.

In one embodiment of the present invention, as shown in FIG. 1, a capacitor 5 is connected in front of the high frequency speaker 1. By connecting the capacitor 5 in this manner, a configuration equivalent to a configuration in which a high-pass filter having a steep characteristic of 12 dB / oct is arranged in front of the high frequency speaker 1 is provided. This will be described.

FIG. 3 shows an equivalent circuit when the inductive type high frequency speaker 1 and the capacitor 5 are connected. The input side of the induction type high frequency speaker 1 includes an inductance L of the power supply coil 15 and an internal resistance R of the power supply coil 15. The signal on the input side is transmitted to the secondary side composed of the conductive portion 17 via the ideal transformer M.

As shown in FIG. 3, the input side of the induction-type high-frequency speaker 1 has a high-pass of 6 dB / oct as shown in FIG. A filter is configured. Cutoff frequency omega ₀ of the high-pass filter is determined by the R / L.

A capacitor 5 is connected to such an induction type high frequency speaker 1.
Are connected, the capacitance C of the capacitor 5 and the internal resistance R of the feeding coil 15 form a 6 dB / oct high-pass filter. Therefore, when the capacitor 5 is connected to the induction type high frequency speaker 1, the inductance 5 includes the inductance L of the feeding coil 15 and the internal resistance R of the feeding coil 15.
A 6dB / oct high-pass filter, a capacitance C of the capacitor 5 and an internal resistance R of the feeding coil 15 of 6dB / oct.
This is equivalent to the cascade connection of oct high-pass filters. Therefore, the inductance L of the feeding coil 15 is
If the cut-off frequency of the high-pass filter composed of the internal resistance R of the power supply coil 15 and the cut-off frequency of the high-pass filter composed of the capacitance C of the capacitor 5 and the internal resistance R of the power supply coil 15 are made equal, FIG. As shown in the figure, it is equivalent to a high-pass filter of 12 dB / oct being arranged in front of the high frequency speaker 1 as a whole.

As described above, when an inductive speaker is used as the high-frequency speaker 1, by connecting the capacitor 5, 12 dB / oct
This is equivalent to the insertion of a high-pass filter having a steep characteristic, and the network circuit 3 is simplified.

It should be noted that the network circuit can be similarly simplified when an inductive speaker is used as the mid-range speaker. In addition, a variable resistor 31 may be connected as shown in FIG. 6 to adjust the cutoff frequency of the high-pass filter composed of the capacitance C of the capacitor 5 and the internal resistance R of the feeding coil 15.

〔The invention's effect〕

According to the present invention, when a speaker system is configured, an induction type speaker is used as a high-range or low-range speaker. A capacitor is connected in series to the input terminal of the inductive speaker. Since a high-pass filter is equivalently configured on the input side of the inductive speaker, if a capacitor is connected in series to the input terminal of the inductive speaker as described above,
A high-pass filter having steep characteristics can be configured, and the network circuit can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram of an example of a speaker system to which the present invention is applied, FIG. 2 is a cross-sectional view of an example of a high frequency speaker according to an embodiment of the present invention, and FIG. 4 and 5 are frequency characteristic diagrams used to describe one embodiment of the present invention. FIG. 6 is an equivalent circuit diagram used to describe another embodiment of the present invention. FIG. 1 is a block diagram of an example of a conventional speaker system. Description of main symbols in the drawings 1: high-range speaker, 2: low-range speaker, 3: network circuit, 5: capacitor, 13: magnet, 15: power supply coil, 16: diaphragm, 17: conductive part.

Claims (1)

(57) [Claims] 1. A vibration plate provided with an annular conductive portion, a power supply coil disposed to face the conductive portion with a predetermined gap, and a magnetic circuit to which the power supply coil is attached, A loudspeaker wherein a capacitor constituting a high-pass filter together with an internal resistance of a power feeding coil is connected in series to the power feeding coil.