JPS63176096A - Diaphragm for speaker - Google Patents

Abstract

PURPOSE:To obtain a diaphragm of which weight, stiffness and internal loss are improved by flame coating ceramic on a sloap part and the whole surface or leastwise the one part of a center cap part and forming the ceramic layer. CONSTITUTION:In case of a paper diaphragm, by utilyzing the lightness and the high stiffness of the ceramic without harming the internal loss and in case of the resinous diaphragm, by utilizing the lightness of the ceramic, the stiffness of the diaphragm is raised and the proper internal loss is obtained. That means the ceramic is flame coated on the sloap part 2 and the whole surface or leastwise the one part of the center cap part 3 of the diaphragm made of paper or resinous film and the ceramic layer is formed. Thus in comparison with the former diaphragm, split vibration can be restrained, the band of piston motion can be extended and high-pitched tone reproduction threshold frequency can be raised. Simultaneously to that, a wide band speaker can be designed and the speaker of which transient characteristic is superior can be obtained by maintaining low pitched reproduction threshold frequency.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a diaphragm for a speaker.

(Prior Art and its Problems) Conventionally, paper, metal plates, and resin have been used as diaphragm materials for speakers. In addition, the physical properties that a diaphragm should generally have include being lightweight to improve efficiency, having a large Young's modulus to improve transient characteristics and widening the band, and suppressing split shooting. However, in order to flatten the frequency characteristics, it is required that the internal loss be appropriately large.

On the other hand, with a diaphragm made of paper, a moderate internal loss can be obtained, but a lightweight and rigid diaphragm is difficult to obtain.
Resin-made diaphragms are lightweight, but have a large Young's modulus, and it is currently difficult to obtain a diaphragm with a moderate internal loss.

(Means for Solving the Problems) The present invention has been proposed to solve the above problems, and its purpose is to reduce the weight of a diaphragm whose substrate is paper or resin. An object of the present invention is to provide a diaphragm with improved rigidity and internal loss.

In order to achieve the above object, the present invention is characterized in that a ceramic layer is formed by thermal spraying ceramic on the entire surface or at least a part of the sloped part and center cap part of a diaphragm made of a resin film or paper. The gist of this paper is a diaphragm for speakers.

In other words, in the case of a paper diaphragm, it is possible to utilize the light weight and high rigidity of ceramic without compromising internal loss.
In the case of a diaphragm made of resin, the rigidity is increased using ceramic to take advantage of its light weight, and a suitable internal loss is obtained.

The present invention will be described in detail below with reference to the drawings.

FIG.
includes free edge or fixed edge. 2 is a slope portion of the diaphragm, and 3 is a center cap portion. In addition, Figure (a) shows the diaphragm before the ceramic is sprayed, and the shaded areas in Figures (b) to j) are the ceramic plate on the surface of the slope section 2 or center camp section 3 of the imaging plate. This is the part where the layer is formed. Figure (b) shows a ceramic layer formed on the entire surface of the slope part 2 of the diaphragm, and figure (C)
Forms a ceramic layer on the center cap part, Figure (dl)
, 11), (i) and (j) form a ceramic layer on the center cap part 3 and a part of the slope part 2 of the diaphragm, and Figures (e), (r) and (h) show the slope of the imaging plate. This is an example in which a ceramic layer is formed in a part of part 2. Also, forming a similar ceramic plate on the back surface of the diaphragm is included in the same embodiment.

Next, Figure 2 (a), (b), (c) and Figure 3 (
a), (bl.

(C) is a half-cut sectional view of the imaging plate. FIG. 2 is a sectional view of a free edge image pickup plate, and FIG. 3 is a sectional view of a fixed edge diaphragm. In the figure, 1 is an edge, 2 is an inclined surface of the diaphragm, 3 is a center cap, and 4 is a ceramic layer. FIG. 2(a) shows the entire surface of one surface of the inclined surface 2 of the diaphragm, FIG. 2(b) shows the entire surface of the center cap 3, and FIG. was formed. In addition, FIG. 3(a) shows a part of one side of the slope portion 2 of the diaphragm and the entire surface of the cap portion 3;
1)) is an example in which a part of the inclined surface 2 of the diaphragm is shaped like a donut and a ceramic layer is formed on the entire surface of the center cap 3, and FIG. Note that FIGS. 2 and 3 are illustrations of a part of FIG. 1.

Although various embodiments have been described in the above embodiments, the first
Various characteristics of FIG. 3(d) (corresponding to FIG. 3(a) as a cross-sectional view) are shown in comparison with a conventional imaging plate (diaphragm without a ceramic layer).

FIG. 4 shows the frequency characteristics of the speaker; the curve 8 shows data of the embodiment of the present invention, and the curve 8 shows data of a conventional comparative example. Compared to the conventional example, the piston motion band for both low and high sounds is wide, and the characteristics are particularly improved in the range from 2000 to 10000)12. Furthermore, FIGS. 5(a) and 5(b) show the distortion characteristics of the speaker, and FIG. 5(a) shows the characteristics of the present invention.
Figure (b) shows the characteristics of the comparative example, where A+ and B+ are frequency characteristics,
A2.82 is the second harmonic distortion characteristic (40dB up), A
3.83 shows the third harmonic distortion characteristic (40 dB increase). The distortion level has been reduced in all bands and the distortion characteristics have been improved.

(Effects of the Invention) As explained above, according to the present invention, a ceramic layer is formed by spraying ceramic on the entire surface or at least a portion of the slope portion and center cap portion of the imaging plate made of a resin film or paper. By doing so, compared to conventional methods, split vibration can be suppressed, the piston motion band can be widened, and the treble reproduction limit frequency can be increased.By maintaining the bass reproduction limit frequency, a wide band can be measured and transient characteristics can be improved. You can get excellent speakers.

In addition, by increasing rigidity and obtaining appropriate internal loss,
Significant distortion reduction can be achieved compared to conventional diaphragms (especially those made of resin).

[Brief explanation of the drawing]

FIGS. 1(a) to (j) are plan views showing embodiments of the present invention,
FIGS. 2(a) to (C) and 3(a) to (C) are sectional views showing embodiments of the present invention, FIGS. 4 and 5(a),
(b) is a characteristic diagram comparing the characteristics of the present invention and a conventional example. 1...Edge part, 2...Slope part (of the imaging plate),
3... Center cap portion, 4... Ceramic layer Patent applicant Foster Ti Kiki Co., Ltd. Agent Patent attorney Michi Takayama, her husband and one other person Figure 1 (j) Figure 2 Figure 3 Procedure Masaharu Ho (spontaneous)

Claims (1)

[Claims] 1. A diaphragm for a speaker, characterized in that a diaphragm made of a resin film or paper has a ceramic layer formed by thermally spraying ceramic on the entire surface or at least a portion of the slope portion and the center cap portion.