JPS61144200A - Speaker - Google Patents

Abstract

PURPOSE:To improve the reproduction of low-pitched sound by making a part of a diaphragm bendable and driving the diaphragm with the part set as a fulcrum. CONSTITUTION:A diaphragm 10 is fixed to a diaphragm holding axis 11 by a flexible member 12. The diaphragm 10 is vibrated vertically by a driving plate 14 with the holding axis set as a fulcrum. Then, it becomes possible to move the diaphragm 10 wider than the amplitude of the driving plate 14 according to the principle of a lever. Thus, the reproduction of low-pitched sound is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a compact speaker that is capable of reproducing low tones with high efficiency.

BACKGROUND OF THE INVENTION Conventional speakers use a dynamic type in which a paper cone is used as a diaphragm and the diaphragm is directly driven to move in parallel by a force generated by a magnetic field and an electric current. (For example, Takeo Yamamoto, "Speaker System (Part 1)" (1988), Radio Gijutsusha, pages 143-147) The conventional speaker as described above will be explained below with reference to the drawings.

FIG. 3 shows a cross section of a conventional speaker. Third
In the figure, 1 is a diaphragm, 2 is a structure whose inner periphery is glued to the outer periphery of the diaphragm 1 and the outer periphery is fixed to the frame 6, 3 is a center cap fixed to the inner periphery of the diaphragm 1, and 4 is a diaphragm. 7 is a voice coil whose lower end is inserted into the gap of the magnetic circuit and whose upper end is fixed to the inner circumferential part of the diaphragm 1; 6 is a damper whose inner circumferential end is fixed to the voice coil 4 and its outer circumferential end to the frame 6;
is a plate fixed to the lower end of the frame 6, 8 is a magnet fixed to the lower end of the plate, and 9 is a pole piece fixed to the lower end of the magnet. The operation of the conventional speed and force configured as described above will be explained below.

First, a magnetic gap is formed between the plate 7 and the pole piece 9 by the magnetic flux of the magnet 8, and when a voice current flows through the voice coil 4 existing in the gap, a force is generated according to Fleming's left hand rule, and a driving force is generated. Become. This driving force causes the diaphragm 1 and the center cap 3 to vibrate and generate sound. At this time, damper 6 and edge 2 are diaphragm 1
, the voice coil 4 is held in place and the edge 2
This prevents the sound behind the diaphragm 1 from leaking to the front. Further, the frame 6 fixes and positions the edge 2, the bumper 6, and the plate 7.

Problems to be Solved by the Invention However, with the above configuration, it is difficult to maintain sufficient sound pressure and reproduce bass sounds with a small speaker with a small diaphragm area because it is difficult to increase the amplitude of the diaphragm. It was impossible. Therefore, bass speakers generally use large-diameter diaphragms, making the system large.
There was a problem that it could not be made smaller.

In view of the above problems, the present invention provides a speaker that can reproduce sufficient bass sounds with a small diaphragm.

Means for Solving the Problems In order to achieve this object, the speaker of the present invention includes a diaphragm that has a bendable portion and is driven using the bendable portion as a fulcrum.

Effect With this configuration, by using the bent part of the diaphragm as a fulcrum and driving a part slightly away from the fulcrum, the amplitude of the entire diaphragm can be made larger than the amplitude of the driving part according to the lever principle. Compared to conventional speakers having a diaphragm, bass reproduction is better.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of a speaker in an embodiment of the present invention, and FIG. 2 is a top view thereof. Figure 1,
In Fig. 2, 1o is a diaphragm, 11 is a diaphragm support shaft, 1
Reference numeral 2 denotes a bending member to which the diaphragm 1o is joined at its flat end and fixed to the diaphragm support shaft 11 at the center; 13 is a frame for fixing the diaphragm support shaft 11; and 14 is the upper end attached to the diaphragm 1.
0, and the lower end thereof is fixed to a voice coil (not shown).

The operation of the speaker configured as above will be described below. First, by transmitting the driving force from the voice coil to the diaphragm 10 via the drive plate 14, the diaphragm 10 is vibrated up and down about the diaphragm support shaft 11 to generate sound. At this time, the diaphragm 10 is fixed to the diaphragm support shaft 11 by the bending member 12 and can be moved in the direction of rotation about the diaphragm support shaft 11 . Further, the frame 13 fixes the diaphragm support shaft 11 and the diaphragm 1o.
is held in place.

As described above, according to this embodiment, when the diaphragm 10 is vibrated up and down by the drive plate 14 with the diaphragm support shaft 11 as the fulcrum, the amplitude is greater than the amplitude of the drive plate 14 according to the lever principle. Since the diaphragm 10 can be moved,
When the area of the diaphragm is the same, compared to a conventional speaker in which the amplitude of the voice coil that drives the diaphragm is equal to the amplitude of the diaphragm, it is possible to better reproduce low frequencies that require a large amplitude. Furthermore, although the diaphragm 1 of a conventional speaker is supported by a diaphragm and a mount 2, according to the present invention, the diaphragm 10 is fixed by a diaphragm support shaft 14, making it possible to maintain a narrow gap with the frame 13. Since the acoustic resistance caused by the air in the gap is used instead of the edge, there is an advantage that there is no need for edges that cause distortion and disturbances in the sound pressure frequency characteristics. Furthermore, since the amplitude of the drive plate 14 can be made smaller than the amplitude of the diaphragm 1o in order to maintain a low pitch, it is also possible to reduce the occurrence of distortion due to non-linearity of the drive system.

In this embodiment, the diaphragm support shaft 11 and the bending material 12 are used as a method of supporting the bent portion of the diaphragm 10, but other methods such as covering the diaphragm support shaft 11 with a pipe, etc. Any structure that allows rotational movement will suffice and the same effect can be obtained. Further, the shape of the diaphragm is not limited to a square, but may be circular, oval, oval, etc. depending on the purpose of use. The diaphragm may be anything as long as it is light and has high rigidity, such as a polymer foam, an aluminum honeycomb sandwich structure, a sandwich structure made of a plastic molded body as a core material, etc.

Effects of the Invention In the present invention, a part of the diaphragm is bendable, and by driving the diaphragm using this as a fulcrum, the amplitude of the diaphragm can be increased with a small drive amplitude, which allows for good bass reproduction even in a small size. Furthermore, since there are no edges and the distortion of the drive section can be reduced, it is possible to realize a speaker with excellent acoustic characteristics.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the configuration of an embodiment of the present invention;
FIG. 2 is a top view thereof, and FIG. 3 is a sectional view showing the structure of a conventional speaker. DESCRIPTION OF SYMBOLS 10...Diaphragm, 11...Diaphragm support shaft, 12...Bending member, 13...Frame, 14...Driving plate . Name of agent: Patent attorney Toshio Nakao and one other IO
... -t&t17A♂hi Figure 2

Claims (1)

[Claims] A speaker comprising a diaphragm having a bendable bending portion, and driving the diaphragm using the bending portion as a fulcrum.