JP3510827B2 - Treble speaker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a treble speaker used in audio equipment and the like.

[0002]

2. Description of the Related Art As this type of high-pitched speaker, various structures have been proposed so far. Here, a high-pitched speaker called a ribbon tweeter will be described. The ribbon tweeter is composed of a magnetic circuit that forms a DC magnetic field and a ribbon that is made of a conductive metal foil and is held freely at both ends in the DC magnetic field.When a signal voltage is applied to the ribbon, the ribbon vibrates. It emits sound waves.

The advantage of the ribbon tweeter is that the diaphragm required by other types of speakers is not necessary, and the coil equivalent in other types of speakers acts as a diaphragm, so that the weight of the speaker vibration system is reduced. It is possible to significantly reduce the weight, and it is possible to reproduce in a high frequency band.

[0004]

However, the ribbon tweeter has a remarkably low electric resistance since the ribbon tweeter corresponds to a coil and is a single metal foil, and impedance conversion is required to achieve electrical matching with the speaker drive circuit. Is essential, parts such as transformers are required, the structure becomes complicated and the manufacturing cost increases, and
Since a large current is applied to the thin metal foil, there is a problem that the metal foil is likely to be damaged due to melting or the like.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a high-pitched speaker which has a simple structure, is easy to manufacture, and has high durability.

[0006]

In order to achieve the above-mentioned object, the high frequency speaker of the present invention has a strip-shaped conductor film on a peripheral portion of a fixed coil made of a conductor thin wire whose surface is insulated. A double coil formed by winding so as not to be in close contact is arranged in a magnetic gap in which a DC magnetic field is formed so that an induced current flowing through the coil made of the conductor film is orthogonal to a magnetic force line of the DC magnetic field, and the fixed It is characterized in that the coil made of the conductor film is vibrated by applying a signal voltage to the coil.

According to this structure, the impedance can be set to any value by adjusting the number of turns of the fixed coil, so that a component for impedance conversion becomes unnecessary. Further, since the induced current flowing through the coil made of the conductor film is not large, it is less likely to be damaged.

It is preferable that the coil made of the conductor film is a one-turn short coil whose both ends are electrically short-circuited, because the electric resistance is reduced and the vibrating portion is lightened.

Further, it is preferable to have the bobbin for positioning the fixed coil at a predetermined position in the magnetic gap and for holding and fixing the fixed coil at the position because the coil can be easily attached to the magnetic circuit.

Further, it is preferable that the fixed coil and the coil made of the conductive film are formed in a substantially rectangular cross section so that the whole of them are located in a substantially uniform magnetic field, because the distortion is reduced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. 1 is a side sectional view of a treble speaker according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a frequency characteristic diagram of the treble speaker of the present embodiment.

In FIGS. 1 and 2, reference numeral 1 denotes a double coil, which is a fixed coil 2 having a substantially rectangular cross section, and a fixed coil 2 having a substantially rectangular cross section. The short coil 3 is fixed so as to be in close contact with the three sides except for.

The fixed coil 2 is formed by winding a thin conductor wire whose surface is insulated, a plurality of times, and the short coil 3 fixes a strip-shaped aluminum foil so that one surface faces the outer peripheral portion of the fixed coil 1. It is formed by winding one turn around the outer circumference of the coil 2 and joining both ends.

Reference numeral 4 denotes a bobbin for holding the fixed coil 2, which is an elongated member made of resin and having a substantially H-shaped cross section.
It is fitted in an elongated magnetic gap having a constant width formed between upper plates 7, 7 (described later). The bobbin 4 positions the fixed coil 2 at a predetermined position in the magnetic gap and holds and fixes it at that position.

The magnetic circuit of this speaker has a pair of rectangular parallelepiped magnets 5, 5 arranged in parallel, a rectangular bottom plate 6 adhered to the lower surfaces of these magnets, and an upper surface of each magnet 5, 5. And a pair of rectangular upper plates 7 and 7 arranged in parallel.
An elongated magnetic gap having a constant width is formed between the seven. The polarization directions of the magnets 5 and 5 are as shown in FIG. 1, and a DC magnetic field line from the N pole to the S pole is generated in the magnetic gap.

As shown in FIG. 2, the fixed coil 2 and the short coil 3 are formed in a substantially rectangular cross section so as to have a cross sectional shape substantially equal to the cross sectional shape of the magnetic gap, whereby the whole is substantially uniform. Since it is located in the magnetic field, distortion is reduced and good frequency characteristics can be obtained. Note that G is a void formed in the non-contact portion of the fixed coil 2 and the short coil 3. The resistance value (impedance) of the fixed coil 2 can be set to any value by adjusting the number of turns, and a transformer or the like for impedance conversion is not required.

When a signal voltage is applied to the fixed coil 2,
Since the short coil 3 is in the same magnetic field as the fixed coil 2, it acts as a secondary coil, an induced current flows, the short coil 3 vibrates due to the interaction with the magnetic field, and a sound wave is emitted. The short coil 3 is closely fixed to the fixed coil 2 on the three sides of the rectangle, and only the remaining one side vibrates. Therefore, the weight of the vibrating portion is extremely light and a high frequency band can be reproduced. Since the induced current flowing through the short coil 3 is not large, the short coil 3 is less likely to be damaged.

The efficiency of electromagnetic induction depends on the distance between the primary coil and the secondary coil and the strength of the magnetic field, but in the present embodiment, both coils 2 and 3 are arranged very close to each other, and closely contacted on three sides. Therefore, the electromagnetic induction has a high efficiency and is a highly efficient speaker.

As shown in FIG. 3, it is understood that the loudspeaker of this embodiment is capable of high frequency reproduction up to 100 KHz, flat frequency characteristics, and high efficiency.

[0020]

As described above, in the high-frequency speaker of the present invention, the impedance can be set to any value by adjusting the number of turns of the fixed coil, so that a component for impedance conversion is unnecessary. The structure is simple and the manufacturing is easy. In addition, since the induced current flowing through the coil made of a conductor film is not large, it is less likely to be damaged,
High durability.

If the coil made of a conductive film is a one-turn short coil whose both ends are electrically short-circuited, the electric resistance is reduced and the vibrating portion is lightened, so that the efficiency is increased.

If the fixed coil is positioned at a predetermined position in the magnetic gap and has a bobbin for holding and fixing the fixed coil at that position, it becomes easy to attach the coil to the magnetic circuit, so that workability during manufacturing is improved. Is improved.

Further, when the fixed coil and the coil made of the conductor film are formed in a substantially rectangular cross section so that they are all located in a substantially uniform magnetic field, distortion is reduced and good frequency characteristics are obtained. To be

[Brief description of drawings]

FIG. 1 is a side sectional view of a treble speaker according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a frequency characteristic diagram of the treble speaker according to the embodiment.

[Explanation of symbols]

1 double coil 2 fixed coil 3 short coil 4 bobbins 5 magnets 6 bottom plate 7 Upper plate

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Claims (4)

(57) [Claims] 1. A magnetic gap in which a DC magnetic field is formed by forming a double coil formed by winding a band-shaped conductor film around the outer periphery of a fixed coil made of a conductor thin wire whose surface is insulated so that a part of the conductor film does not adhere to the coil. In order to oscillate the coil made of the conductor film, an induction current flowing in the coil made of the conductor film is arranged so as to be orthogonal to the magnetic force line of the DC magnetic field, and a signal voltage is applied to the fixed coil. A speaker for high-pitched sound characterized by the above. 2. The high-frequency speaker according to claim 1, wherein the coil made of the conductor film is a one-turn short-circuit coil whose both ends are electrically short-circuited. 3. The high frequency speaker according to claim 1, further comprising a bobbin for positioning the fixed coil at a predetermined position in the magnetic gap and holding and fixing the fixed coil at the position. 4. The fixed coil and the coil made of the conductor film are formed in a substantially rectangular cross section so that the whole of the fixed coil and the coil made of the conductive film are located in a substantially uniform magnetic field. High frequency speaker.