JPS60244195A - Speaker - Google Patents

Abstract

PURPOSE:To accomplish the correction to change automatically a sound pressure level in a high frequency in accordance with the magnitude of the sound by disposing a ring main body cut by a slit and a short-circuit piece of the slit on a magnetic gap of a field part. CONSTITUTION:At the time of a large sound volume, heat produced from a voice coil 25 is transmitted to a ring 19 due to heat dissipation and convection, which causes a resistance of a short-circuit piece 21 of a high positive resistance temperature coefficient to rise, and suppresses a rising relaxation in a high frequency of an impedance of the voice coil 25, whereby a sound pressure in a high frequency drops. Meanwhile, at the time of a small sound volume, the resistance of the short-circuit piece 21 for comprising a part of the ring 19 is left low, and a rise in a high frequency of the impedance of the coil 25 is suppressed, thereby obtaining a sound pressure rise in a high frequency. As a result, a high frequency is automatically rised by a speaker at small sound volume with respect to a audible feeling where a high frequency cannot be listened at the time of a small sound volume while at the time of a large sound volume a high frequency is reduced, both of which are executed as the correction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to speakers used in various types of audio equipment.

Configuration of a conventional example and its problems A conventional speaker will be explained with reference to FIG. 1 is a plate provided with a center pole 2, 3 is a ring-shaped magnet, and 4 is a ring-shaped upper plate, which constitute a field section 5. The inner peripheral part of a frame 6 is coupled to the upper plate 4 of this field part 5, and the outer peripheral part of a diaphragm 8 is fixed to the outer peripheral part of this frame 6 while being sandwiched between it and a gasket 7. A voice coil 11 whose intermediate portion is supported by a damper 10 is coupled to the inner peripheral edge of the diaphragm 8 so as to fit correctly into the magnetic gap 9 of the field section 5. However, in such a configuration, as shown by the broken line in FIG. 3, the sound pressure decreases significantly due to the impedance increase in the high frequency range of the voice coil 11, resulting in insufficient sound pressure in the high frequency range. In FIG. 3, a represents sound pressure and b represents impedance.

Conventionally, a highly conductive cap 12 was provided on the part of the center ball 2 constituting the field part 5 in contact with the magnetic gap 9, as shown in FIG. Magnetic gap 9 of upper plate 4 constituting section 5
By providing a ring 13 with good S conductivity in the portion in contact with the oscilloscope, the frequency characteristics shown by the solid line in FIG. 3 are realized.

However, such conventional speakers have a problem in that the high-frequency sound pressure level cannot be automatically changed according to the loudness of the sound, and does not match human auditory sense.

OBJECT OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks.The present invention automatically changes the high-frequency sound pressure level according to the loudness of the sound, and relatively increases the high-frequency level when the sound is small. On the other hand, the purpose of this invention is to provide a speaker that can lower the level of high frequencies when the sound is loud, and that matches the human auditory sense.

Structure of the Invention In order to achieve the above object, the speaker of the present invention includes a field part including a plate having a center ball part, a magnet, and an upper plate, and a magnetic gap is formed between the center pole part and the upper plate. and a ring body made of at least a metal with higher conductivity than the material of the plate and having a slit extending the entire length in the width direction at one location in the circumferential direction, and made of a material having a positive temperature coefficient of resistance greater than at least the material of the ring body. and a shorting piece that short-circuits both ends of the ring body divided by the slit, and the ring body and the shorting piece are arranged in a magnetic gap of the field part.

According to this configuration, when the sound is loud, heat generation from the voice coil increases the resistance of the shorting piece, which has a large positive temperature coefficient of resistance, suppressing the relaxation of the increase in voice coil impedance in the high range, and accordingly When the sound is low, the resistance decreases, and the rise in voice coil impedance is suppressed in the high range, the level of the high range increases, and a frequency response that matches human hearing is automatically obtained. It will be done.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a sectional view of a speaker according to an embodiment of the present invention, and 14 is a field section, which includes a plate 15 having a center pole section 15a in the center, and a ring-shaped magnet 16. , and a ring-shaped upper plate 17' are bonded together. In this field section 14,
A magnetic gap 18 is provided between the upper part of the center pole portion 15a and the upper plate 17.

An annular ring 19 is externally fitted and fixed on the surface of the center pole portion 15a that is in contact with the magnetic gap 18. As shown in FIG. 5, this ring 19 is made of a good S conductor and has a slit 20a extending the entire length in the width direction at one location in the circumferential direction.
The ring body 20 is composed of a ring body 20 having a slit 20a, and a shorting piece 21 having a large positive temperature coefficient of resistance that short-circuits both ends of the ring body 20 separated by a slit 20a. The ring body 20 is made of a metal having a higher conductivity than at least the material of the plate 15, such as copper, aluminum, or silver, and has a positive temperature coefficient of resistance greater than at least the material of the ring body 20. Made of metal, semiconductor, etc. An inner peripheral part of a frame 22 is coupled to the upper plate 11 of the field section 14, and a diaphragm 24 is attached to the outer peripheral part of the frame 22 while being sandwiched between it and a gasket 23.
A voice coil 25 is coupled to the inner periphery of the diaphragm 24, and the middle part of the voice coil 25 is supported by a damper 26. I'm addicted to it.

Next, the operation will be explained. At high volume, voice coil 25
The heat generated from the ring 19 is transmitted to the ring 19 by radiation and convection, which increases the resistance of the shorting piece 21, which is a part of the ring 19 and has a high positive resistance humidity coefficient, and reduces the rise in the voice coil beadance in the high range. The sound pressure in the high range is reduced. On the other hand, when the volume is low, the resistance of the shorting piece 21, which is a part of the ring 19 and has a high positive temperature coefficient of resistance, remains low, and the rise in voice coil impedance in the high range is suppressed, and the increase in the voice coil impedance in the high range is suppressed. A sound pressure increase can be obtained.

FIG. 6 is an explanatory diagram of the relationship between the frequency and sound pressure impedance of the speaker, where the solid line indicates the low volume and the broken line indicates the high volume. Further, C is sound pressure and d is impedance. In this way, the frequency characteristics in the high range change depending on the volume, making it possible to create sounds that match the human hearing sense.

Note that the ring 19 is connected to the magnetic gap 1 of the upper plate 17.
A similar effect can be obtained even if it is provided on the surface in contact with 8.

Further, in order to directly sense the heat generated from the voice coil 25, a shorting piece 21 having a high positive temperature coefficient of resistance and forming a part of the ring 19 is installed on the voice coil 25, and is connected to the ring body 20. A configuration may be adopted in which a short circuit is made between the two using a copper wire or the like.

As described in detail, according to the present invention, in response to human hearing, which makes it difficult to hear high frequencies at low volumes, the speaker automatically increases high frequencies at low volumes, and lowers high frequencies at high volumes. It is possible to perform correction by reducing the area, and the structure is simple and can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional speaker, and FIG. 2A is a sectional view of a conventional speaker. B is a cross-sectional view of the field part of a conventional speaker in which a good conductor is installed in a part of the field part in order to increase the high-frequency sound pressure level, and Fig. 3 is a cross-sectional view of the field part of a conventional speaker. 4 is a cross-sectional view of the speaker in an embodiment of the present invention, FIG. 5A is a front view of the ring,
FIG. 6 is an explanatory diagram of the frequency characteristics of the speaker shown in FIG. 4. FIG. 14... Field part, 15... Plate, 15a...
Center pole product, 16...Magnet, 17...
Upper plate, 18...Magnetic gap, 20...Ring body, 20a...Slit, 21...Short circuit agent Yoshi Morimoto Private use 1 Figure 2 Oka: J, Layout

Claims (1)

[Scope of Claims] 1. A field part comprising a plate having a center pole part, a magnet, and an upper plate, with a magnetic gap formed between the center pole part and the plate; a ring body made of a metal with high conductivity and having a slit extending the entire length in the width direction at one location in the circumferential direction; A subinika comprising a short-circuit piece that short-circuits both ends of a ring body, and the ring body and the short-circuit piece are arranged in a magnetic gap of the field part. 2. The speaker according to claim 1, wherein the ring body is attached to the center pole part. 3. The speaker according to claim 1, wherein the ring body is attached to the upper plate. 4. Claim 1, wherein the shorting piece is attached to the voice coil and connected to the ring body by a conductive wire.
The speaker according to any one of Items 1 to 3.