JPH0338997A - Loudspeaker - Google Patents

Abstract

PURPOSE:To divid keen peak to be observed in the high area limit of a sound pressure frequency characteristic and to acquire the smooth sound pressure frequency characteristic by using an axially asymmetric diaphragm for which the apex of a dome-shaped diaphragm is set in a position different from the center of a voice coil. CONSTITUTION:For the axially asymmetric dome-shaped diaphragm, the apex of a dome part 18 is set in the position different from the center of the diaphragm 20 and a distance from the apex to a peripheral edge part 19 is made various for positions. Then, such a diaphragm is adopted. In such the case, the intrinsic oscillation frequency of an axially asymmetric dome-shaped diaphragm 20 is low in a direction, where the distance from the apex of the dome part 18 to the peripheral edge part is long, and the frequency is high in a direction where the distance is short. Thus, since the various intrinsic oscillation frequencies can be acquired in various directions, the keen peak is diffused and the smooth sound pressure frequency characteristic can be acquired.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a speaker that improves sharp peaks that occur at the high frequency limit, and particularly to a speaker for reproducing mid-to-high frequencies and a speaker having a diaphragm integrated with the edge of a dome. It is related to.

2. Description of the Related Art In recent years, in order to improve the acoustic characteristics of loudspeaker devices and expand the high-frequency limit of the reproduction band, attention has been paid to E/ρ, that is, the ratio of Young's modulus to density of the material forming the diaphragm. Efforts have been made to improve the rigidity of the titanium diaphragm by applying nitriding, ceramic coating, or diamond coating to the titanium diaphragm.

Hereinafter, the conventional speaker as described above will be explained with reference to the drawings.

FIG. 6 shows the structure of a conventional speaker. In FIG. 6, reference numeral 1 denotes a high E/ρ diaphragm, and an edge 3 is attached to the outer circumference of a dome portion 2 in the center. A vibration system in which a voice coil 4 is bonded to the outer circumference of the diaphragm 1 is attached to an upper plate 5. Magnet 6, lower plate 7
The voice coil 4 is held by a center ring 8 so as to fit into the magnetic gap of the field part made up of the above without eccentricity, and is fixed by a baffle plate 9 and a mounting screw 10.

The operation of the speaker configured as above will be described below.

When an input voltage is applied to the voice coil 4 in the magnetic gap, a driving force is generated, causing the dome-shaped diaphragm 1 to vibrate.

Problems to be Solved by the Invention However, the above configuration has the following problems. In other words, when the frequency component of the input signal is low, the diaphragm 1 is hard enough to maintain its shape, but in the high frequency range, it is unable to maintain its shape and the sound pressure frequency characteristics become high. A sharp peak (high frequency reproduction limit frequency: Jh) as shown in FIG. 7 is generated in the region. As shown in FIG. 8, the vibration state at this high frequency reproduction limit frequency fh is as shown in FIG. It was something that would occur.

The present invention solves the above conventional problems and provides a speaker with smooth sound pressure frequency characteristics up to high frequencies.

Means for Solving the Problems In order to solve this problem, the speaker of the present invention has the apex of the dome section at a different position from the center of the diaphragm, and the distance from the apex to the periphery varies depending on the position. Additionally, it has a configuration that employs a non-axisymmetric dome diaphragm.

Effect: With this configuration, the natural vibration frequency of the non-axisymmetric dome diaphragm is low in the direction where the distance from the apex of the dome portion to the peripheral portion is long, and is high in the direction where the distance is short. Therefore, by having various natural vibration frequencies depending on the direction, sharp peaks are dispersed and smooth sound pressure frequency characteristics are realized.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a speaker in one embodiment of the present invention. In FIG. 1, reference numeral 12 indicates a lower plate 14 having a center ball 13 and a ring-shaped magnet 15.
This is a field part composed of a ring-shaped upper plate 16 as well, and on this field part 12, a non-axisymmetric magnet with a circular peripheral edge and a top located at a different position from the center is provided on the field part 12 via a center ring 17. A diaphragm 20 is provided with an edge 19 on the outer periphery of the dome portion 18, and is fitted into the magnetic gap 21 of the field portion 12 at the periphery of the dome portion 18. A voice coil 22 is connected thereto, and the peripheral edge of the edge 19 of the diaphragm 20 is pressed and fixed onto the center ring 17 by a baffle plate 24 which is connected onto the field part 12 with screws 23 to form a speaker.

The diaphragm 20 is constructed as shown in FIG. 2 and FIG.
This is a diaphragm 20 made by pasting 9 together. FIG. 3 is a view of the diaphragm 20 viewed from above, with the diaphragm 20 starting from the apex 25.
The distance to the peripheral edge of the dome portion 18 differs depending on the position.

The operation of the speaker configured as above will be described below.

First, the method by which the driving force vibrates the diaphragm 20 is that when an input signal is applied to the voice coil 22, the voice coil 22 in the magnetic air gap 21 generates an amplitude in the vertical direction according to Fleming's left hand rule, and vibrates. Drive the plate 20. Therefore, at low frequencies, it is possible to maintain the shape and obtain smooth sound pressure frequency characteristics. As the frequency increases, nodes first occur in the longer direction from the apex 25 to the peripheral edge of the dome portion 18, but since the shape is not axially symmetrical,
No sharp peaks or dips occur. When the frequency becomes higher still, the nodes sequentially move in the direction of the shorter distance from the apex 25 to the peripheral edge of the dome portion 18, causing split resonance and no peak at a specific frequency is generated.

As described above, according to this embodiment, the speaker is composed of a non-axisymmetric dome diaphragm in which the apex of the dome portion 18 is different from the center of the diaphragm 20, and by using the non-axisymmetric dome diaphragm, the sound The sharp peak seen at the high end of the pressure frequency characteristic is divided, and a smooth sound pressure frequency characteristic can be obtained. If the apex 25 of the dome portion 18 of the present invention is even slightly different from the center of the diaphragm, the effect can be obtained, and the practical range in the direction of the outer periphery is 95% from the center of the diaphragm.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a sectional view of a semi-dome diaphragm showing a second embodiment of the present invention. In the same figure, 26 is vertex 2
5 is a diaphragm in which a substantially conical cone portion 27 and an edge 19 are bonded to the outside of a dome portion 18 that is different from the center.

The operation of the speaker configured as described above will be described below.

First, the method for causing the driving force to vibrate the diaphragm is the same as that described above. Therefore, at low frequencies, it is possible to maintain the shape and obtain smooth sound pressure frequency characteristics. As the frequency increases, nodes first occur in the direction of the longer distance from the apex 25 of the dome portion 18 to the peripheral edge of the dome portion 18, but since the shape is not axially symmetrical, no sharp peaks or dips occur. When the frequency further increases, the nodes sequentially move in the direction of shortening the distance from the apex 25 of the dome part 18 to the peripheral edge of the dome part 18, causing split resonance and no peak at a specific frequency is generated.

As described above, according to the second embodiment of the present invention, the speaker is a non-axisymmetric semi-dome diaphragm in which the apex 25 of the dome portion 18 is different from the center of the diaphragm. By using this, sharp peaks seen at the high end of the sound pressure frequency characteristic are divided, and smooth sound pressure frequency characteristics can be obtained.

A third embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a sectional view of a dome and edge integrated diaphragm showing a third embodiment of the present invention. In the figure, 28 is a diaphragm in which a dome portion 18 whose apex 25 is different from the center, a substantially conical cone portion 29 and an edge portion 19 are integrally molded.

The operation of the speaker configured as described above will be explained below.

First, the method for causing the driving force to vibrate the diaphragm is the same as that described above. Therefore, at low frequencies, it is possible to maintain the shape and obtain smooth sound pressure frequency characteristics. When the frequency becomes higher, first, the nodes sequentially move in the direction of the shorter distance from the apex 25 of the dome part 18 to the periphery of the dome part 18, causing split resonance, and no peak occurs at a specific frequency.

As described above, according to the third embodiment of the present invention, the speaker is composed of a non-axisymmetric dome and an edge-integrated diaphragm in which the apex 25 of the dome portion 18 is different from the center of the diaphragm. By using a dome-shaped or edge-shaped diaphragm, the sharp peaks seen at the high range limit of the sound pressure frequency characteristics are divided, and smooth sound pressure frequency characteristics can be obtained.

Effects of the Invention Since the present invention is configured as described above, the following effects can be obtained.

(1) The joint part of the outer periphery of the diaphragm with the voice coil bobbin is circular, the apex of the dome-shaped diaphragm is at a different position from the center of the voice coil, and the distance from the apex to the outer periphery of the diaphragm By using a non-axisymmetric diaphragm that differs depending on its position, we have created an excellent speaker that can split the sharp peaks seen at the high end of the sound pressure frequency response and obtain smooth sound pressure frequency response. This is something that can be achieved.

(2) Furthermore, by using a semi-dome-shaped diaphragm that has a substantially conical cone part on the outside of the dome part, and the central dome part is non-axisymmetric, the high-frequency limit of the sound pressure frequency response can be improved. This makes it possible to realize an excellent speaker that can obtain smooth sound pressure frequency characteristics by dividing the sharp peaks seen in the .

(3) Furthermore, by using a diaphragm with an integrated dome edge part that has a substantially conical cone part and an edge on the outside of the dome part, the central dome part is non-axisymmetric. This makes it possible to realize an excellent speaker that can obtain smooth sound pressure frequency characteristics by dividing the sharp peaks seen at the high end of the pressure frequency characteristics.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a speaker in an embodiment of the present invention;
FIG. 2 is a sectional view of a diaphragm used in the speaker, FIG. 3 is a top view of the same, and FIGS. 4 and 5 are sectional views of diaphragms for speakers of other embodiments. Figure 6 is a sectional view of a conventional speaker, Figure 7 is a cross-sectional view of a conventional speaker.
The figure is a sound pressure frequency characteristic diagram of a conventional speaker, and FIG. 8 is a vibration state diagram of the same speaker at a high frequency reproduction limit frequency fh. 12... Field part, 17... Center ring, 18... Dome part, 19... Edge, 20... Vibration plate, 21...Magnetic air gap, 22...Voice coil, 24...
・Baffle board.

Claims (3)

[Claims] (1) The joint part with the voice coil in the peripheral part is circular, and the apex is at a position different from the center of the peripheral part,
A speaker comprising a non-axisymmetric dome diaphragm having a dome part whose distance from its apex to the peripheral edge of the dome part varies depending on the position, and in which the voice coil is fitted into a magnetic gap of a field part. (2) The speaker according to claim 1, wherein the speaker is a semi-dome-shaped diaphragm having a substantially conical cone portion on the outside of the dome portion, and the central dome portion is a non-axisymmetric diaphragm. (3) The speaker according to claim 1, wherein the diaphragm is integrated with the edge of the dome and has a substantially conical cone and an edge on the outside of the dome, and the central dome is a non-axisymmetric diaphragm. .