JPS58200696A - Dynamic loudspeaker - Google Patents

Abstract

PURPOSE:To reduce the ringing of low sound part and to improve parts housing rate, by setting the diameter of two corner parts, which are located farther from voice coil connecting position, out of four corner parts of a speaker larger than the diameter of two corner parts which are located closer to the voice coil connecting position. CONSTITUTION:The diameter of corner parts, which are located closer to the connecting position of a voice coil 8, out of four corner parts of an edge part 4 having a roll shape section of a rectangular flat diaphragm 1 of a dynamic loudspeaker is set to be R3=R4 and R'4=R'3. The diameter of other corner parts, which are located farther from the voice coil 8, is set to be R1=R2 and R'1=R'2. Also R1=R2>R3=R4 and R'1=R'2>R'3=R'4. The diameter of farther corners are made larger. The amplitude of farther side and closer side to the coil 8 is made to be equal with respect to eccentric driving force to reduce the ringing at low sound part, and to improve the housing rate of parts.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a rectangular diaphragm whose outer periphery is supported on a frame via an edge member, and a voice coil located at a position eccentric to either side of the center of the rectangular diaphragm in the long side direction of the rectangular diaphragm. To provide an electrodynamic speaker configured to be driven by applying a driving force of 1, and which can prevent a rolling phenomenon in which only a voice coil drive part of a rectangular diaphragm vibrates greatly. The purpose is to

In general, most speaker diaphragms have a prototype shape, and as audio equipment such as audio multiplexing television receivers and cassette tape recorders with radio receivers become more compact, the shape of speakers has become an issue. ing. Therefore, since most of the audio devices housed in the speaker are rectangular parallelepipeds, speakers having rectangular diaphragms have been developed. This speaker with a rectangular diaphragm has a large number of mechanical parts such as a motor by making the voice coil position eccentric from the center of the long side of the rectangular diaphragm and moving the magnetic circuit on the back of the speaker to the edge of the frame. This is advantageous in improving the parts storage ratio of audio equipment such as a tape recorder with a radio receiver and making the audio equipment more compact.

1 and 2 show a conventional electrodynamic speaker having a rectangular diaphragm. In Figures 1 and 2,
7 is a yoke in which the center ball 9 is integrally formed; 6 is an annular magnet fixed on the yoke 7; 6 is an annular plate fixed on the magnet 6; An annular magnetic gap is formed between the center ball 9 and the outer peripheral surface thereof. The magnetic circuit is fixed to the bottom surface of the rectangular frame 1o. 1 is a rectangular plane diaphragm, and this rectangular plane diaphragm 1 is supported by an edge member 2 in an opening of a frame 1o. 3 is a coil bobbin coupled to a position eccentric from the center in the long side direction of the rectangular plane diaphragm 1, and a voice coil 8 is wound around this coil bobbin 3, and this voice coil 8 is inserted into the magnetic gap. ing. , 4 is a damper that supports the voice coil bobbin 3 on the frame 1o. Above edge member 2
The radius of each of the four corner portions of is R12R2=Rs
=R4, R+'2R2'=R5'=R4'.

However, in the electrodynamic speaker mentioned above.

When the driving force F by the voice coil 8 is applied to the rectangular plane diaphragm 1Vc in the low frequency range, the vibration state shown in FIG. 3 is taken.

That is, since the radii of the four corner portions of the edge member 2 are equal as described above, the stiffnesses of the two opposing sides of the edge member 20 are equal. Therefore, error?
The stiffness at both ends of member 2 is +, and 2 is Kl = 2.
When the rectangular plane diaphragm 1 is driven by the driving force of the voice coil 8 coupled at a position offset by a distance l from the center in the long side direction, only the coupled side of the voice coil 8 is used as shown by the broken line. The problem has been that the voice coil 8 vibrates greatly, that is, rolls, and the voice coil 8 comes into contact with the magnetic gap, causing abnormal noise and damage to the voice coil 8.

The present invention solves these conventional drawbacks,
Among the four corner portions of the engineering/engine member, by setting the diameters of the two corner portions far from the voice coil coupling position to be larger than the diameters of the two corner portions near the voice coil coupling position, By making rolling less likely to occur, it is possible to improve the parts storage rate of audio equipment. This provides an eccentrically driven rectangular speaker that can be used.

The present invention will be described below with reference to drawings of embodiments. 4 and 5 show an embodiment of the present invention, and in FIGS. 4 and 6, the same parts as in the conventional example are given the same numbers. In this embodiment, among the four corner portions of the edge member 2 whose cross section is roll-shaped, the diameter of the two corner portions near the voice coil coupling position is R.
32R4, R♂2R4', and on the other hand, the parts of the two opposite corners far from the voice coil coupling position are also R+ =
R2, R1'-R2', R12R2) R5=
R4°R+'=R2'>Rs'=R4', and the diameter of the corner part on the side farther from the voice coil coupling position is set larger. In the edge member 2 for a rectangular diaphragm, since the short side and the long side intersect at right angles at some corners, strain concentrates and becomes a major factor in determining the stiffness of the edge member 2. In other words, the larger the diameter of the corner part, the more the strain is dispersed and the support can be moved more easily. When the voice coil 8 position is eccentric to drive the rectangular plane diaphragm 1,
As in the conventional example, the diameter of a portion of each corner is equal. In other words, if the stiffness is equal, a large force will be applied to the part of the corner on the side near the voice coil 8, and as described above, in order to obtain a sharper amplitude, in this embodiment, the voice coil side with a smaller corner diameter has a lower stiffness Because the diameter is large, it becomes stiff and difficult to move, and on the far side, the diameter is large, making it soft and easy to move. Therefore, the iJ function is to make the eccentric driving force have almost the same amplitude on the far side of the voice coil 8 as on the near side, and this can significantly improve low frequency rolling, as shown in Figures 6 and 7. is another embodiment of the present invention, in which the cross-sectional shape of the edge member 12 is waveform in FIGS. The effects can be expected. Further, as shown in FIGS. 8 and 9, the edge member 12 is the same as that in the second embodiment, but the diaphragm may be changed from a planar shape to a rectangular cone diaphragm 11. In the case of dynamic plates, the diaphragm is generally heavy because it has a sandwich structure consisting of a surface material and a core material.
Although the efficiency is lower than that of conventional cone-shaped speakers, this embodiment can improve efficiency by preventing rolling and by reducing the weight of the diaphragm using the rectangular cone.

As detailed above, according to the present invention, the edge member has a rectangular diaphragm whose diameter is set to be much larger at a corner part far from the voice coil drive position than the diameter of two corner parts near the voice coil drive position. Since the outer periphery of the rectangular diaphragm is configured to be supported by the frame, the stiffness at the opposing parts and J parts is asymmetrical, making it difficult for low-frequency rolling phenomenon to occur when the voice coil drive part is asymmetrical. It has the advantage of being able to

[Brief explanation of the drawing]

Fig. 1 is a top view of a conventional electrodynamic speaker, Fig. 2 is a sectional view of the same speaker, Fig. 3 is an explanatory diagram of the low range rolling of the same speaker, and Fig. 4 is an illustration of the electrodynamic speaker of the present invention. FIG. 5 is a top view showing an embodiment of the same speaker, FIG. 6 is a top view showing another embodiment of the same speaker, FIG. 7 is a plan view of essential parts of the same speaker, and FIG. 9 is a top view of still another embodiment of the same speaker, and FIG. 9 is a plan view of a main part of the same speaker. DESCRIPTION OF SYMBOLS 1... Rectangular plane diaphragm, 2... Edge member, 3... Coil bobbin, 8... Voice coil, 11... Rectangular cone Vibration plate, 1
2... Engineering/funnel components, name of agent Patent attorney
Toshio Nakao and 1 other personFigure 1Figure 2Figure 3Figure 4

Claims (1)

[Scope of Claims] (1) A rectangular diaphragm whose outer periphery is supported on a frame via an edge member, and the driving force of the voice coil is applied to a position eccentric from the center in the long side direction of the rectangular diaphragm. The edge member is configured to be driven by the four corners thereof, and the diameters of the two corner parts far from the voice coil coupling position are larger than the diameters of the two corner parts near the voice coil coupling position. (2) The electrodynamic speaker according to claim 1, wherein the edge member has a roll-shaped cross section; (3) The edge member 3. The electrodynamic speaker according to claim 2, wherein the cross-sectional shape is waveform. (4) The electrodynamic speaker according to claim 1, wherein the rectangular diaphragm is a planar diaphragm. (6) The electrodynamic speaker according to claim 1, wherein the rectangular diaphragm is a rectangular cone diaphragm.