WO2007077854A1

WO2007077854A1 - Speaker

Info

Publication number: WO2007077854A1
Application number: PCT/JP2006/326002
Authority: WO
Inventors: Kiyoshi Yamagishi
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2005-12-28
Filing date: 2006-12-27
Publication date: 2007-07-12
Also published as: JP2007180973A

Abstract

Provided is a speaker including: a frame connected to a magnetic circuit; a diaphragm connected to the outer circumference of the frame; a voice coil connected to the diaphragm and having part arranged in a magnetic gap of the magnetic circuit; and a dust cap connected to least one of the diaphragm and the voice coil. The dust cap has dome cross section of elliptical arc shape. Thus, it is possible to improve high end feature of the speaker and increase the band.

Description

Specification

Speaker

Technical field

[0001] The present invention relates to a speaker used in various audio devices.

Background art

[0002] In a speaker, the dust cap has a function of preventing a foreign matter from entering the voice coil and resonating at a frequency determined by its diameter and curvature to determine a high frequency limit frequency. A conventional speaker using such a dust cap is shown in Fig. 3 and Figs. 4A and 4B. Fig. 3 shows a cross-sectional view of a conventional speaker, and Figs. 4A and 4B show cross-sectional views of a conventional dust cap. A conventional speaker is composed of a frame 21, a magnetic circuit 22, a diaphragm 23, a voice coil 24, a damper 25, and a dust cap 26. The magnetic circuit 22 includes a magnet 27, a plate 28, and a yoke 29. The voice coil 24 is disposed in a magnetic gap 30 formed between the plate 28 and the yoke 29.

[0003] Normally, high-end characteristics are important forces in full-range speakers, high-frequency speakers, etc. Conventional dust caps have mainly focused on setting the high-frequency limit frequency. Therefore, the shape of the dome can be either a simple arc (indicated by the first radius R1) or two radii (first radius R1 and second radius R2) as shown in Figures 4A and 4B. The arc was a combination of. These are concentrated constants and often have a sharp peak at a constant frequency during high-frequency resonance. However, in recent years, with the advancement of audio systems, there has been a problem that loudspeakers are required to have a broader and smoother characteristic, which is difficult to achieve with conventional dust cap speakers.

[0004] For example, Patent Document 1 is known as prior art document information as a dust cap for a speaker.

Patent Document 1: Japanese Patent Laid-Open No. 2005-252775

Disclosure of the invention

[0005] The present invention relates to a frame coupled to a magnetic circuit and an outer peripheral portion of the frame. A diaphragm, a voice coil coupled to the diaphragm, a part of which is disposed in the magnetic gear of the magnetic circuit, and a dust cap coupled to at least one of the diaphragm and the voice coil And a speaker in which the dome section of the dust cap has an elliptical arc shape. In this way, it is possible to improve the speaker end-to-end characteristics and increase the bandwidth.

Brief Description of Drawings

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

FIG. 2 is a frequency characteristic diagram showing a comparison between the speaker of the present invention and a conventional speaker.

FIG. 3 is a cross-sectional view of a conventional speaker.

FIG. 4A is a cross-sectional view of a conventional dust cap of a speaker.

FIG. 4B is a cross-sectional view of another dust cap unit of a conventional speaker.

Explanation of symbols

1 frame

2 Magnetic circuit

3 Vibration

4 Voice coil

5 Damper

6 Dust cap

7 Magnet

8 plates

9 York

10 Magnetic gap

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. Note that the drawings are schematic views and do not show the positional relationship correctly. The magnet used in the magnetic circuit of the present invention is preferably a high energy product rare earth magnet. Samarium-cobalt magnets and neodymium magnets are preferably used. Plates and yokes can be used as normal magnetic circuits The soft magnetic material used can be used.

FIG. 1 is a cross-sectional view of a speaker according to an embodiment of the present invention. This speaker is also composed of a frame 1, a magnetic circuit 2, a diaphragm 3, a voice coil 4, a damper 5, and a dust cap 6. The magnetic circuit 2 is composed of a magnet 7, a plate 8, a yoke 9 and a force. The voice coil 4 is disposed in a magnetic gap 10 formed between the plate 8 and the yoke 9. A broken line portion indicated by a symbol A in FIG. 1 is an extended locus in which the dome section force provided for explaining the shape of the dust cap 6 also continues. In the present embodiment, the dust cap 6 has an elliptical arc shape (an arc indicated by 6a to 6b in FIG. 1) in the dome section, and changes at each point on the elliptical arc (6a to 6b). For this reason, the resonance affected by the curvature is distributed over a wide range of frequencies, so that sharp peaks at the high frequency limit are suppressed. Further, since the center side of the dome has a long diameter, the outer peripheral portion has a smaller curvature and a larger rise than the center side. As a result, the strength of the outer periphery that receives the most force, such as the voice coil and diaphragm, is increased in the dome, so that the entire resonance frequency is shifted to a high range. As a result, it is possible to realize a loudspeaker with smoother and higher end characteristics. In the speaker of FIG. 1, the ratio of the dust cap to the vibration area of the vibration system is large. In such a case, the effect of the present invention is particularly great. FIG. 2 is a frequency characteristic diagram showing the characteristic improvement effect according to the present embodiment. A comparison of frequency characteristics between the present embodiment and the conventional example is shown with the same conditions except for the dust cap shape. Symbol B in Fig. 2 indicates the frequency characteristics of the conventional dust cap, and symbol C indicates the frequency characteristics of the speaker using the dust cap according to the present invention. In Fig. 2, the horizontal axis represents frequency (Hz) and the vertical axis represents sound pressure (dB).

[0010] It should be noted that the dust cap used in the present invention is characterized by its shape as described above, and other components such as the diaphragm can be the same as the conventional product. The reason why the dust cap having the shape of the present invention has been devised so far is that the ratio of the dust cap to the vibration area of the vibration system is so large in the conventional speaker, so the resonance characteristics of the dust cap itself are discussed. This is because there was little effort to do. Industrial applicability

As described above, the present invention provides a frame coupled to a magnetic circuit, a diaphragm coupled to an outer peripheral portion of the frame, and the diaphragm coupled to the diaphragm, and a part of the diaphragm is coupled to the magnetic circuit. In a speaker comprising a voice coil disposed in a magnetic gap of the speaker and a dust cap coupled to at least one of the diaphragm and the voice coil, the dome section of the dust cap is formed into an elliptical arc shape so that the high end of the speaker is Improved characteristics and wider bandwidth can be realized.

Claims

The scope of the claims

[1] a frame coupled to a magnetic circuit;

A diaphragm coupled to the outer periphery of the frame;

A voice coil coupled to the diaphragm and partially disposed in a magnetic gear of the magnetic circuit;

A dust cap coupled to at least one of the diaphragm and the voice coil;

Have

A speaker whose dome section of the dust cap has an elliptical arc shape.

2. The speaker according to claim 1, wherein the elliptical arc shape has a major axis on the center side of the dome cross section.