JPS60177798A - Coaxial flat speaker - Google Patents

Abstract

PURPOSE:To flatten a sound pressure frequency characteristic by decreading a step between a low frequency diaphragm surface and each edge surface fixed to the peripheral to suppress disturbance of a sound from a diaphragm for high/intermediate frequencies due to a reflected sound of an edge. CONSTITUTION:A low frequency diaphragm 21 is fixed and supported by frames 25 and 26 through edges 23 and 24 fixed to outer and inner peripheral parts 21a and 21b, which are provided with steps 27 and 28 so that the surface of the diaphragm 21 can approach to respective edges 23 and 24 as much as possible, that is, respective peripheral parts 21a and 21b will be thinner than an inside part, and respective edges 23 and 24 are fixed to the steps 27 and 28. With said constitution, since the thickness of the peripheral parts 21a and 21b is adjusted so that a step between the surface of the diaphragm 21 and those of respective edges 23 and 24 will be minimized, it can be suppressed that sounds from a high/ intermediate frequency diaphragm 22 are disturbed by reflected sounds from the edges 23 and 24.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a speaker with improved sound pressure frequency characteristics.

Conventional configurations and their problems In recent years, many flat-plate speakers with flat sound pressure frequency characteristics have been commercialized. Furthermore, coaxial flat-plate speakers, in which the flat-plate speakers are separated into low-pitched and mid-high-pitched speakers and arranged coaxially, have been commercialized because of their excellent sound image localization.

A conventional coaxial flat plate speaker will be explained below with reference to FIG. (1) is an annular and flat bass diaphragm that constitutes the woofer, and its inner and outer peripheral edges are respectively edged (2).
(3) through the outer frame (4) and the inner frame (
5) K is fixedly supported. (6) is a voice coil for driving the bass diaphragm (1), and is suspended in the bass magnetic circuit (7) via a tamper (8). The bass magnetic circuit (7) is supported by the outer frame (4). Note that the voice coil (6) is usually fixed at the position of the resonance mode node of the bass diaphragm (1),
Expansion of the reproduction band is being attempted by a means called node drive. (9) is a diaphragm for middle and high frequencies in the shape of a flat plate forming the tweeter, and is fixedly supported within the inner frame (5). (10 is a voice coil for driving the mid-high sound diaphragm (9), and is located in the mid-high sound magnetic circuit (B). The L distribution side frame (5) is the voice coil for driving the mid-high sound diaphragm (9). ) and support plate 4 to the medium/high frequency magnetic circuit αη side.The signal is applied to each voice coil (6) 4 via a frequency separation circuit.However, according to the above configuration, , the sound emitted from the mid-high frequency diaphragm (9) is reflected by the gills around it; This has the disadvantage that the sound pressure frequency characteristics are disturbed, and the influence of reflection from the ox edge surface is
The larger the difference in level between the bass diaphragm table 101 and the edge surface, the more noticeable it becomes.One way to reduce this effect is to reduce the thickness of the bass diaphragm, but the bass diaphragm has a large area and the resonant frequency In order to increase the height, it was impossible to reduce the thickness.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and aims to provide a coaxial flat plate that reduces reflection from edges and smooths out disturbances in sound pressure frequency characteristics.

Structure of Departure J In order to achieve the above object, the coaxial flat plate of the present invention has an annular bass diaphragm placed on the outer periphery of the mid-high sound diaphragm and coaxially with the mid-high sound diaphragm. The thickness of at least one of the inner circumference and outer circumference of the bass diaphragm is changed relative to the thickness of the inner circumference, and an edge is fixed to the circumference whose thickness has been changed. The difference in level between the surface and the surface of the bass diaphragm is reduced.

Description of examples Hereinafter, one embodiment of the present invention will be described based on FIG. 2.

eυ is an annular and flat bass diaphragm that makes up the woofer, and in the center of it is a flat, mid-to-high frequency diaphragm that makes up the tweeter and is placed coaxially (in a concentric position). has been done. And the bass diaphragm mentioned above? υ is fixedly supported to the outer and inner frames via edges fixed to its outer and inner peripheral edges (21a, 21b). Further, the outer and inner peripheral edges (21a) and (21b) of the bass diaphragm Qυ are arranged so that the surface of the bass diaphragm 49 and each edge)-surface are as close as possible, that is, each peripheral edge (21a) ) (21b) is provided with a step so that it is thinner than the inner part, and each gill, ;ni) (goods) is fixed to this step. Note that the other configurations are the same as those of the conventional example, so the explanation thereof will be omitted.

According to the above configuration, the thickness of each peripheral edge part (2ia) (2ib) of the bass diaphragm Q1) is set such that the level difference between the surface of the bass diaphragm eη and each edge (c) is minimized. Since it has been adjusted, it is possible to suppress as much as possible the sound from the mid-high frequency diaphragm (A) from being disturbed by the reflected sound of Edge@■. Therefore, the sound pressure frequency characteristics, which were greatly disturbed in conventional speakers, are flattened, making it possible to realize a coaxial plate speaker with good sound.

In addition, for the above-mentioned diaphragm 12μ, a polymer foam, a polymer film molded into an uneven shape, a hexagonal columnar honeycomb cell of aluminum titanium, etc. are used as the core material, and at least one of them is made of aluminum, titanium, etc. A structure made of light and highly rigid thin foil is suitable.

By the way, in the embodiment E, the circumference M of the bass diaphragm is
Although the part is shown to be changed in stages, it is also possible to change the changing part to Qi in a stepwise manner as shown in Figure y63, or to change the changing part in stages as shown in Figure 4. The entire portion C may be changed sequentially, or if the bass diaphragm is thin as shown in FIG. 5, the peripheral portion may be made thicker.

Furthermore, in the above embodiment, the thickness of both the outer circumference and the inner circumference of the bass diaphragm was changed, but for example, the thickness of only one of them may be changed. According to the structure of the invention, the difference in level between the surface of the bass diaphragm and the surface of each edge is reduced, so that the sound from the mid-to-high frequency diaphragm is prevented from being disturbed by sound reflected from the edges as much as possible. Therefore, the sound pressure frequency characteristics, which were greatly disturbed in conventional speakers, become flat.
A coaxial flat speaker with good sound can be realized.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a conventional example, FIG. 2 is a schematic sectional view of one embodiment of the present invention, and FIGS. 3 to 5 are enlarged sectional views of main parts of other embodiments. t2υ...Bass diaphragm, (21a)...Outer periphery, (21b)...Inner periphery, (A)...Medium and treble diaphragm, (Incorporated)... Engineering/υji, 01) 02 C
I-... Peripheral agent Yoshihiro Moriki \ Figure 3 Figure 4 Figure 1

Claims (1)

[Claims] (2) A bass diaphragm is arranged in an annular manner on the outer periphery of the mid-high sound diaphragm and coaxially with the mid-high sound diaphragm, and at least one of the inner periphery and the outer periphery of the bass diaphragm is provided. While changing the thickness of the inner part thereof,
This coaxial flat plate speaker is designed to reduce the level difference between the edge surface fixed to the periphery whose thickness has been changed and the bass diaphragm surface.