JPS5921198A - Speaker - Google Patents

Abstract

PURPOSE:To improve both efficiency and directivity of a speaker, by setting plural ring-shaped diaphragms on the same axis with those having larger diameters put more backward. CONSTITUTION:A recess part 11 of a small diameter and a recess part 12 of a large diameter are formed around a center projection part 10 of a bottom plate 9. Cylindrical magnets 15 and 16 are fixed to these parts 11 and 12 respectively, and top plates 17 and 18 are fixed on the magnets 15 and 16 respectively. Then ring-shaped diaphragms 27-30 containing voice coils 23-26 formed on polymer films 19-22 are fixed between the part 10 and the plate 17, the plate 17 and a supporting projected part 13, the part 13 and the plate 18, and the plate 18 and a side wall 14 respectively. The diaphragms 27-30 are set on the same axis, and those diaphragms having larger diameters are put more backward. Thus it is possible to drive these diaphragms with the same phase.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a speaker equipped with a ring-shaped diaphragm.

Structure of the conventional example and its problems As shown in FIGS. 1(a) and 1(b), in the conventional speaker, a cylindrical magnet 4 is fixed to a bottom plate 3 having a convex portion 2 in the center. A voice coil 7 is mounted on the polymer film 6 between the annular top plate 6 fixed on the magnet 4 and the convex portion 2 of the bottom plate 3.
The diaphragm 8 on which the diaphragm 8 is formed is fixed.

A speaker with this configuration has a wide vibration surface and is highly efficient. However, since the vibration surfaces are arranged on the same plane, there is a drawback that the directivity is poor.

OBJECTS OF THE INVENTION In view of the above drawbacks, the present invention provides a speaker with high efficiency and excellent directivity.

Structure of the Invention In order to achieve the above object, the present invention has a structure in which a plurality of ring-shaped diaphragms are arranged on the same axis, with the diaphragms having a larger diameter being shifted to the rear.

With this configuration, the sound waves output from each diaphragm have a substantially spherical wave shape, and can have excellent directivity.

DESCRIPTION OF EMBODIMENTS A speaker according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 2(a) and (b), the bottom plate 9
, a concave portion 11 (concave recess) with a small diameter and a concave portion 12 with a large diameter are provided around the central convex portion 10, and between the concave portion 11 and the concave portion 12. The inner side of the support convex portion 13 of the cylindrical body protrudes high. The outer peripheral portion of the bottom plate 9 is provided with both cylindrical side walls 14 that are lower than the supporting convex portions 13. Recessed portions 11 and 1
2 have cylindrical magnets 15 and 16 fixed thereto, respectively, and above the magnets 15 and 16 are cylindrical top plates 17 and 18 whose upper inner side 1 protrudes high.
is fixed. Convex portion 10 in the center of bottom plate 9
and the inside of the top plate 17 are configured to be at the same height, the outside of the top plate 17 and the inside of the support projection 13, and the outside of the support projection 13 and the top plate 18.
The inner side of the top plate 18, the outer side of the top plate 18, and the side wall 14 are configured to have the same height.

Polymer films 19 to 19 are provided between the central convex portion 10 of the bottom plate 9 and the top plate 17, between the top plate 17 and the support convex portion 13, between the support convex portion 13 and the top plate 18, and between the top plate 18 and the side wall 14, respectively. Ring-shaped diaphragms 27 to 30 on which pois coils 23 to 26 are formed are fixed onto the diaphragm 22 . The diaphragms 27 to 30 are coaxially located, and the larger the diameter, the further the diaphragms 27 to 30 are located at the rear. By adjustment, the diaphragms 27 to 30 can be driven in the same phase. As a result, the sound waves output from the speaker of this embodiment can have a substantially spherical wave shape and have excellent directivity. Moreover, like conventional speakers, the large vibration surface of the speaker of this example is large, so
It is also highly efficient.

Effect of the invention , · .

As described above, the present invention can achieve high efficiency and excellent directivity by arranging a plurality of ring-shaped diaphragms on the same axis and disposing the ones with larger diameters farther back.

[Brief explanation of drawings]

Figure 1(a) is a plan view of a conventional speaker, Figure 1(b)
2(a) is a plan view of a speaker according to an embodiment of the present invention, and FIG. 2(a) is a sectional view thereof. 9...Bottom plate, 19-22...
- Polymer film, 23-26...Voice coil, 27-30...Vibration plate. Name of representative Patent attorney Toshio Nakao and 1 other person 1st
Figure J2

Claims (1)

[Claims] A speaker in which multiple ring-shaped diaphragms, each with a voice coil formed on a polymer film, are arranged coaxially on a bottom plate, with larger diameter diaphragms being shifted further back.