JPH0588600B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speaker system in which a compressor for supplying air is built into a speaker box supporting a speaker that holds a vibration system in the air by supplying air, thereby making the device compact. At the same time, you can improve the sound quality.

The following drawings illustrate embodiments of the present invention:
FIG. 1 shows an example of a speaker used in the present invention, in which a diaphragm 2 and a partition wall 3 are provided in the center of a bobbin 1, and voice coils 4 and 4' are wound around both ends of the bobbin.
These are integrally formed into a vibration system as a vibration element 5, and center poles 7, 7' of a magnetic circuit having magnets 6, 6', yokes 8,
The voice coils 4, 4' are placed between the magnetic poles 8', and the magnetic fluid 9 is injected so as to fill the space between the voice coil portion and the magnetic poles.

The center pole has an air hole 1 that penetrates through its center and branches to empty chambers 10 and 10' in the bobbin.
1, 11' from a compressor 13 through a pipe 12 to prevent the bobbin 1 from coming into contact with the magnetic circuit, and to prevent the bobbin 1 from coming into contact with the internal spaces 10, 10'.
It is designed to perform damping and support the vibrating element. Since the cavity in the bobbin is sealed with magnetic fluid, the compiler can be smaller than a case where no magnetic fluid is used.

The magnetic fluid is a mixture of fine magnetic powder such as magnetite or ferrite and a diester solvent, dioctyl azelate. It stores the heat of the voice coil, suppresses temperature rise, suppresses resonance without disturbing vibration, and exhibits a self-centering effect.

The vibrating element 5 is supported on the speaker box 14 by bridges 15, 15'. This bridge is provided in an arcuate shape facing each other on the upper plate of the speaker box 14, and inside the bridge are provided yokes 8, 8'.
is fixed, and the diaphragm 2 is loosely fitted into the opening 16 of the speaker box 14, and is not fixed to the speaker box with a damper or the like like known speakers.

17 and 18 are the height of the diaphragm 2, that is, the opening 16
These sensors detect the position of the diaphragm, and are attached to the edge of the opening 16 in two, upper and lower, and detect the position of the diaphragm by projecting light and detecting the reflected light from the edge of the diaphragm. This sensor detects when the maximum vibration movement range of the diaphragm exceeds the opening edge thickness either above or below, and the signal is amplified by an amplifier 19 to determine the amount of air flowing through the pipe 12 in the empty chambers 10 and 10'.
The valve 20 is actuated to regulate and distribute the water. In other words, when the diaphragm 2 protrudes upward, the sensor 17 detects it and uses the valve 20 to inject more air into the air chamber 10 and pull down the vibrating element. to pull up the vibrating element. As a result, the position of the diaphragm 2 is maintained properly relative to the edge of the opening 16 as shown in FIG.

As shown in Figure 3, due to the vibration of the diaphragm 2, the negative pressure on the back side leaks to the front side compared to the positive pressure on the front side, canceling out the sound, or even if it is not enough to leak, the sound output is distorted due to the misalignment. In addition, the voice coil is always kept in a positive position with respect to the magnetic pole, and the highest sound quality can be maintained with the lowest input.

4 and 5 show the relationship between the air supply and the electrical signal to the voice coil in a speaker such as the above example in which the vibration system is held in the air by air supply. A horn-shaped sound path 21' is provided from the back of the tweeter 21 and woofer 22 of the high frequency range and exits from the hole 14' of the box, and the woofer 22 of the speaker facing upward is provided on the top surface, and a quarter-spherical shell reflector 23 is provided. In a wide frequency range speaker that is placed over the top of the box 14 to diffuse sound forward, switches S ₁ , S ₂ and a lever L are installed at the front end of the top plate of the box 14.
Switch S ₁ turns on and off the current from the power plug 24 to the compressor 13, switch S ₂ turns on and off the electric signal from the amplifier 25 to the voice coils 4 and 4', and lever L turns on and off the electric signal from the compressor 13 to the amplifier 25. This is a lever that adjusts the valve that distributes the amount of air sent into the air chambers 10, 10', and thereby raises and lowers the position of the vibration system and maintains it at an appropriate position.

These operations were performed by turning off switch _S2 , turning on switch _S1 without inputting an electrical signal to the speaker, moving lever L, and lifting the voice coil, which had sunk in contact with the magnetic circuit, to an appropriate position. After that, turn on the switch _S2 and input the electrical signal to the speaker.

This prevents the voice coil from being damaged by friction or the like due to electrical signals being input to the voice coil while it is in contact with the magnetic circuit, and it is possible to always produce sound with the best sound quality than the speaker without any problems.

It should be noted that if the sensors 17 and 18 of the above-mentioned example, which are activated by the switch _S1 , are provided and the valve 20 is operated, the lever L can be omitted, and it is possible to automate the operation so that the switch _S2 is then turned on by a time relay.

Figures 6 and 7 show an example in which the compressor 13 for supplying air to the speakers of each of the above examples is built into the box 14 of the speaker box. The compressor 13, which is provided with a reflecting plate 23 and sends air to the speaker 26, is inserted into a chamber 27 that partitions the inside of the box through a sound-absorbing material 28 such as glass wool, to block the vibration noise of the compressor and to separate the partitioned chamber 27. The outside is open and the soundproofing material is covered with a perforated punching plate 29,
It radiates heat from the compressor.

The punching plate 29 may be a plate having a large number of heat dissipating folds 30 as shown in FIG.

FIG. 9 shows that holes 32 and 33 are provided in the upper part of the side plate and the bottom plate of a part of the box 14, and a vibration-proof rubber 34 is provided above the hole 33.
The compressor 13 is attached through the hole, and a bent passage 35 from the hole 33 to the hole 32 is formed around the sound absorbing material 28, which absorbs the sound of the compressor and cools the compressor by ventilation.

This makes use of the space inside the speaker box to house the compressor, making the speaker unit smaller and easier to handle than installing an external compressor.It also prevents resonance due to the weight of the speaker box, making it easier to handle the compressor. Many benefits can be obtained, such as effective sound insulation inside the box.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a vertical sectional view of the first embodiment, FIGS. 2 and 3 are longitudinal sectional views of a part of FIG. 1, and FIG. 4 is a longitudinal sectional view of the second embodiment. Perspective view, 5th
The figure is a block diagram of FIG. 4, FIG. 6 is a perspective view of the third embodiment, FIG. 7 is a cross-sectional view showing the compressor of FIG. 6 and its surroundings, and the fourth embodiment is shown in FIG. 6 is a cross-sectional view showing a fifth embodiment of the compressor and its surroundings; FIG. 9 is a vertical cross-sectional view showing a sixth embodiment of the compressor shown in FIG. 6 and its surroundings; 2... diaphragm; 14... speaker box, 5
...Vibration element, vibration system, 13...Compressor.

Claims (1)

[Claims] 1. In a speaker box equipped with a speaker whose vibration system is held in the air by air supplied by a compressor, the compressor is housed in a soundproof box and installed in a space between the speaker box and the speaker, and the speaker box and the soundproof box are connected to each other. The speaker system is characterized by being integrated and used for both purposes, and the weight of the speaker box is increased by a compressor.