JP3023579U - Ribbon type electroacoustic transducer - Google Patents

Abstract

(57) [Abstract] [Problem] Demonstrating good conversion efficiency up to extremely high frequency bands, as well as mid and low frequency bands.
High conversion efficiency is achieved over the entire band without damaging the operation of the ribbon diaphragm due to braking or reflection. A vibrating plate having a ribbon-shaped vibrating plate arranged in a gap G formed in a magnetic circuit M and a conductive plate arranged in the vicinity of the vibrating plate are provided. In the ribbon-type electroacoustic transducer in which magnetic fluxes generated by currents flowing in the opposite directions to and from each other cancel each other out, the conductive plate 7 is arranged on substantially the same plane so as to surround the diaphragm 2, and the conductive plate 7 It is connected to one end of the plate 2, and an input signal is connected between the other end of the diaphragm 2 and a part 7 a of the conductive plate 7.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to an electroacoustic transducer used for energy conversion between electric energy and acoustic energy, and more particularly to a ribbon electroacoustic transducer having a ribbon diaphragm.

Conventionally, in this type of ribbon-type electroacoustic transducer, when a speaker is taken as an example, since the diaphragm itself generates a driving force, there is no loss due to the transmission of the force, and the vibration is reduced. It is possible to reproduce up to a high frequency, and the band extends to the ultrasonic band.

FIG. 3 is a perspective view showing an example of a conventional ribbon-type electroacoustic transducer. The magnetic circuit M is composed of magnets 4 and 4, magnetic poles 5A and 5B, and a yoke 6, and a gap G having a predetermined interval is formed between the magnetic poles 5A and 5B. The ribbon diaphragm 2 is arranged in the gap G, and is made of a thin metal plate having a low electric density such as aluminum or beryllium, which has good electric conductivity. It is supported at an appropriate interval so as not to come into contact with 5B.

Since the ribbon diaphragm 2 has an extremely low electric impedance, it needs to be converted into an appropriate impedance when it is connected to an amplifier (not shown). The matching transformer 1 is for converting into an appropriate impedance, and is connected to the diaphragm 2 by the lead wires 3 and 3.

[0005]

[Problems to be solved by the device]

 However, in the above-mentioned conventional ribbon-type electroacoustic transducer, the lead wire 3 from the matching transformer 1 to the ribbon diaphragm 2 and the slight inductance of the ribbon diaphragm 2 itself deteriorates the high frequency characteristics of the speaker. It was a big factor. For this reason, the vibrating plate 2 itself generates a driving force, has no loss associated with the transmission of the force, and has an excellent characteristic, but in reality, the conversion efficiency decreases as the frequency increases. It was inevitable.

In order to solve this problem, as shown in FIG. 4, the lead wires 2 and 2, the ribbon diaphragm 2 and the lead wire 2 and the lead wire 2 and the ribbon diaphragm 2 are so arranged as to cancel out the interductance of the lead wires 3 and 3. Alternatively, it has been proposed that a lead plate (hereinafter, simply referred to as a lead wire) 3a has a folded structure in which the whole is parallel. This structure can cancel the magnetic flux generated by each of the reciprocating currents and reduce the inductance. However, in this structure, in order to effectively cancel the magnetic flux, it is necessary to bring the lead wire 3a on the back surface of the ribbon diaphragm 2 as close to the ribbon diaphragm 2 as possible, which impedes the operation of the ribbon diaphragm 2. There will be problems.

The object of the present invention is to exhibit good conversion efficiency up to an extremely high frequency band, and to prevent the operation of the ribbon diaphragm from being hindered by braking or reflection even in the middle and low frequency bands. The purpose of the present invention is to provide a ribbon-type electroacoustic transducer that achieves high conversion efficiency over the entire band.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the invention of claim 1 is a ribbon-shaped diaphragm disposed in a gap formed in a magnetic circuit, and a conductive plate disposed in proximity to the diaphragm. In a ribbon-type electroacoustic transducer that cancels magnetic flux generated by currents flowing in opposite directions flowing through the diaphragm and the conductive plate, the conductive plate is arranged so as to surround the vibration plate. Is characterized by.

According to a second aspect of the present invention, in the ribbon-type electroacoustic transducer according to the first aspect, the conductive plate is arranged on substantially the same plane as the diaphragm.

According to a third aspect of the present invention, in the ribbon-type electroacoustic transducer according to the first aspect, the conductive plate is supported on one end side of the diaphragm, and is connected to the other end side of the diaphragm. An input signal is connected to a part of the conductive plate.

[0011]

[Embodiment of device]

 Hereinafter, an embodiment of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a ribbon-type electroacoustic transducer according to the present invention. In addition, the same reference numerals are given to the portions having the same functions as those of the above-described conventional example, and the duplicate description will be appropriately omitted. In this embodiment, the yoke 6 has a U-shaped cross section, and the magnets 4 and 4 are arranged inside the arms on both sides. The magnetic poles 5A and 5B are arranged in the gap G inside the magnets 4 and 4, and the slopes are formed so that the gap G side becomes thin. The ribbon diaphragm 2 is arranged between the gaps G. The upper surfaces of the yoke 6, the magnets 4, 4 and the magnetic poles 5A, 5B are substantially flush with each other, and the conductive plate 7 is arranged on the upper side thereof.

The conductive plate 7 is arranged so as to surround the ribbon diaphragm 2. The conductive plate 7 is a good conductor and is arranged in substantially the same plane as the ribbon diaphragm 2. Further, a slight gap is provided between the conductive plate 7 and the ribbon vibrating plate 2 so that they are not in electrical contact with each other. That is, the conductive plate 7 is arranged between the magnetic circuit M and the horn when the front surface of the magnetic circuit M or the horn is used, and insulated from both sides. The ribbon diaphragm 2 has one end electrically connected to the conductive plate 7 via the support point 8, and the other end between the support point 9 and a part 7a of the conductive plate 7 on the other end side. , Is configured to power the signal input.

Since the ribbon-type electroacoustic transducer of this embodiment is configured as described above, as shown by the arrow in FIG. 1, the current I ₁ flowing in the ribbon diaphragm 2 and the current I ₁ surrounding the current I ₁ are surrounded. The currents I ₂ and I ₃ flowing in the conductive plate 7 are in opposite directions, and the magnetic flux generated by the current can be canceled. Moreover, since the conductive plate 7 is arranged so as to surround the ribbon diaphragm 2 at a close range, the magnetic flux is effectively cancelled, and the inductance is greatly reduced, so that the conversion efficiency in the high frequency band is high. It has a great effect to prevent the decrease of

Further, since the conductive plate 7 does not block the front and back of the ribbon diaphragm 2 at all, it does not adversely affect the operation of the ribbon diaphragm 2 and the characteristics in the low frequency band region due to the braking caused by the air resistance. Does not deteriorate, and reflection does not disturb the characteristics in the middle frequency band. Of course, there is no generation of distortion or deterioration of transient characteristics due to these phenomena, so extremely excellent sound quality can be obtained over the entire band.

The supporting points (feeding points) 9 and 10 are used after being converted into an appropriate impedance by using the matching transformer 1 because the electric impedance between them is extremely low. At this time, in order to sufficiently enhance the effect of improving the high frequency band, it is preferable to shorten the lead wire 3 of the transformer 1 as much as possible and to keep the forward wire and the return wire in close contact with each other to keep the inductance of the lead wire 3 low.

FIG. 2 is a diagram showing the characteristics of the ribbon-type electroacoustic transducer according to this embodiment in comparison with a conventional example. A curve A shows a frequency-relative sensitivity characteristic to which the present embodiment is applied, a curve B shows a conventional example shown in FIG. 3, and a curve C shows a conventional example shown in FIG. It can be seen that the curve B is not improved in the high frequency band. In curve C, the lead wire 3 is arranged on the back surface of the ribbon diaphragm 2, so that the characteristics in the high frequency band are improved, but the disturbances that are considered to be caused by reflection and braking are observed in the middle and low frequency bands. It appears that the characteristics have deteriorated. On the other hand, it can be seen that the curve A exhibits good conversion efficiency up to a high frequency band as compared with the curve B. Further, as compared with the curve C, the operation of the ribbon diaphragm 2 is not disturbed by braking or reflection even in the middle and low frequency bands.

The present invention is not limited to the above-described embodiments, and various modifications and changes can be made, which are also within the scope of the present invention. For example, although the description has been given by using the speaker as an example, the same can be applied to the microphone.

[0018]

[Effect of device]

 As described in detail above, according to the present invention, good conversion efficiency can be exhibited even in an extremely high frequency band. Even in the middle and low frequency bands, high conversion efficiency is achieved over the entire band without damaging the operation of the ribbon diaphragm due to braking or reflection.

According to the third aspect, the conductive plate is supported on one end side of the diaphragm, and the input signal is connected between the other end side of the diaphragm and a part of the conductive plate. It becomes possible to assemble in advance. In other words, in the conventional ribbon-type electroacoustic transducer, the diaphragm is directly fixed in the magnetic circuit by screwing or soldering, so it is extremely difficult to repair it in the event of a failure such as burnout due to excessive input. It was According to the present invention, as described above, since it is possible to assemble in advance, there is an effect that even if a failure occurs, the assembly can be replaced very easily and the performance after repair is stable. .

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a ribbon-type electroacoustic transducer according to the present invention.

FIG. 2 is a diagram showing characteristics of the ribbon-type electroacoustic transducer according to the present embodiment in comparison with a conventional example.

FIG. 3 is a perspective view showing a positional relationship between a matching transformer, a ribbon diaphragm, and lead wires connecting these in a conventional ribbon-type electroacoustic transducer.

FIG. 4 is a circuit diagram showing a method of reducing inductance of a lead wire and a ribbon vibrator of a conventional ribbon-type electroacoustic transducer.

[Explanation of symbols]

 1 transformer 2 ribbon diaphragm 3 lead wire M magnetic circuit 4 magnet 5A, 5B magnetic pole 6 yoke 7 conductive plate 8, 9 contacts

Claims (3)

[Scope of utility model registration request] 1. A ribbon-shaped vibrating plate arranged in a gap formed in a magnetic circuit, and a conductive plate arranged in proximity to the vibrating plate, wherein the vibrating plate and the conductive plate are provided. A ribbon-type electroacoustic transducer in which magnetic fluxes generated by currents in opposite directions cancel each other out, wherein the conductive plate is arranged so as to surround the diaphragm. 2. The ribbon-type electroacoustic transducer according to claim 1, wherein the conductive plate is arranged on substantially the same plane as the diaphragm. 3. The ribbon-type electroacoustic transducer according to claim 1, wherein the conductive plate is supported on one end side of the diaphragm, and the other end side of the diaphragm and a part of the conductive plate. A ribbon-type electroacoustic transducer characterized in that an input signal is connected between the ribbon and the electroacoustic transducer.