close

Вход

Забыли?

вход по аккаунту

?

JPH0884395

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPH0884395
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to
audio speakers, and more particularly to audio speakers for faithful reproduction of a whole
range of audio frequencies with a single speaker. It is.
[0002]
2. Description of the Related Art In recent years, with the development of recording technology,
the frequency band of an audio signal to be recorded is wide and the dynamic range (ratio of
strong and weak audio signals) is extremely large. In general, the voice frequency band (20 Hz to
30 KHz) is divided into two or three so that each divided frequency band is shared by dedicated
speakers.
[0003]
When the audio frequency band is divided into three, the speaker is a conical diaphragm having
a diameter of at least 20 cm in the low region and a diameter of about 10 cm in the middle
region, and a dome region of several cm or less in the high region. Shaped diaphragms are
common.
Usually, in the audio field, as described above, a method in which three speakers are divided is
referred to as a 3-way speaker system, and the entire frequency band is divided into low and
11-05-2019
1
high frequencies, and each dedicated spin is used. The method of sharing to a car is called a twoway speaker system. In order to drive each of these speakers as a speaker dedicated to the
divided frequency band, the output signal from the amplifier is combined with an inductor (L), a
capacitor (C) and a resistor (R). Thus, the frequency band is divided and supplied according to the
characteristics of the speaker to be shared.
[0004]
Naturally, the speech waveform reproduced and synthesized by the three speakers is different
from the amplifier output signal waveform. This difference in waveform is due to the phase
difference of the frequency components that make up the real voice, but in the case of
continuous sound, acoustically, even if the waveform is different, if the frequency components
are the same, auditory sense There is no difference in However, in real speech, there is almost no
continuous sound.
[0005]
For this reason, generally, a single speaker having a conical diaphragm with a diameter of about
10 cm is made to correspond to the entire frequency band. Also in the case of a planar speaker
having a planar diaphragm, it has been attempted to cope with the entire frequency band with a
diaphragm of about 8 cm × 15 cm. However, with these speakers it was impossible to faithfully
reproduce part of the low band from the following point.
[0006]
That is, with a conical diaphragm having a diameter of about 10 cm or a flat diaphragm having a
size of 8 cm × 15 cm, it is necessary to increase the driving force per unit area in order to
reproduce a high sound range of sufficient sound pressure. For this purpose, it is realized by
utilizing the divided vibration of the diaphragm or increasing the magnetic flux density of the
magnetic gap. However, in order to reproduce the lowest sound pressure range, a diaphragm
amplitude of about 2 mm or more is necessary, and in particular, a driving coil that enables this
amplitude in a flat diaphragm speaker. Or there was no way to support the reel.
[0007]
11-05-2019
2
SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of such
conventional loudspeakers by means of planar loudspeakers, and provides a wide dynamic range
of voice signals in a wide frequency band. It is intended to enable faithful reproduction with a
single speaker.
[0008]
In the planar speaker according to claim 1, the four corners of the rectangular drive coil mounted
on the planar diaphragm or the winding frame of the drive coil are connected to each other. By
means of a flat plate spring with a plurality of slits (slits) which do not lead, this radial direction
is made parallel to the flat diaphragm and radiates from four directions in accordance with the
amplitude of the flat diaphragm. In addition, a vibration system including a flat diaphragm, a
drive coil, a winding frame of the drive coil, and the like is supported so that the flat plate spring
can expand and contract.
[0009]
According to a second aspect of the present invention, in the planar speaker of the first aspect,
the drive coil and the winding frame of the drive coil are triangular, and the three corners thereof
are supported.
[0010]
According to a third aspect of the present invention, in the planar speaker of the first aspect, the
drive coil and the winding frame of the drive coil are polygons having five or more sides, and the
corners of the polygon are supported.
[0011]
According to a fourth aspect of the present invention, in the planar speaker according to the first
aspect, the drive coil and the winding frame of the driving coil are circular, and the driving coil or
the winding frame of the driving coil is radially supported at a plurality of points. Become.
[0012]
[Functions] A flat plate spring having a plurality of slits (slits) which are not connected to each
other, and radially supports the drive coil or its winding frame, and also the entire circumference
of the flat diaphragm and the speaker body structure The space between the frames is covered
with a sound absorbing flexible film, which can sufficiently guarantee the freedom of the
vibration system in the direction of vibration, and a single speaker with a relatively small area of
diaphragm, Faithful reproduction of a large dynamic range of audio is possible.
11-05-2019
3
[0013]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Generally, as shown in FIG. 1, when
a signal current flows in a coil placed in a magnetic field, the speaker is in the direction
perpendicular to the magnetic field lines based on Fleming's left-hand rule. It vibrates according
to the frequency and amplitude of the signal current, and the vibration of this coil is transmitted
to the diaphragm and taken out as an acoustic signal.
In order to vibrate the diaphragm faithfully to the signal current, the support structure for
supporting the entire vibration system including the drive coil is free in the vibration direction,
and it is necessary to exert a restraining force in other directions.
[0014]
In the present invention, for example, the drive coil wound in a rectangular shape or the four
corners of the drive coil winding frame is a flat spring which is parallel to the flat diaphragm and
the other end is a speaker. It fixes to the frame which is a structure, and supports the whole
vibration system.
The vibration mode of the leaf spring fixed at one end is, as shown in FIG. 2, that the free end has
freedom in the direction perpendicular to the surface, but has no freedom in the direction
parallel to the surface.
However, as shown in FIG. 3, when this plate spring is also connected to both ends in the middle
via the structure of the diaphragm, it has no freedom in the required vibration direction of the
vibration system.
[0015]
In order to obtain this degree of freedom, it is conceivable to use a pre-curved leaf spring, but in
a leaf spring having a curve, as shown in FIG. 4, the vibration origin of the vibration system It is
difficult to fix the position of the vibration system at the zero level state of the signal waveform,
and there is a possibility that the position change of the vibration system may occur due to the
11-05-2019
4
temporal change of the degree of curvature.
[0016]
Therefore, in the present invention, as shown in FIG. 5, the vibration system is supported by flat
plate springs having a plurality of cuts (slits) which are not connected to each other.
The plate spring has no degree of freedom in the surface direction of the plate spring at the
origin of vibration, but only in the direction of vibration.
Furthermore, once the vibration system deviates from the vibration origin, it expands and
contracts according to the amplitude value in the direction connecting the fixed end of the plate
spring and the vibration system support end within the range of elasticity of the plate spring and
vibrates in the vibration direction of the vibration system Give them enough freedom to do it.
That is, even if the flat plate spring shown in FIG. 5 is connected at two or more places via the
diaphragm structure, it does not lose freedom in the required vibration direction of the
diaphragm. , The diaphragm structure can be supported.
[0017]
Next, a method for blocking the reproduction sound generated from the front and back of the
diaphragm will be described.
Generally, in the two-way or three-way speaker system described above, the speaker sharing the
low frequency band has a sufficiently large diaphragm and a sufficient distance to the driving
point of the diaphragm. No special structure is required for handling the end, for example, by a
method in which the material integral with the diaphragm is made flexible at the end of the
diaphragm and then fixed to the frame of the speaker body structure. Cut off the playback sound
from the front and back of the diaphragm.
[0018]
11-05-2019
5
The planar speaker according to the present invention has a structure capable of sufficiently
securing the freedom of vibration even at the end of the diaphragm and adaptable to vibrations
with large amplitude, including the entire circumference of the diaphragm end and the speaker
structure. It covers the gap between it and the body frame and blocks the reproduction sound of
the front and back of the diaphragm. A sound absorbing flexible film is pasted on the entire
circumference of the diaphragm end in a plane parallel to the diaphragm with a width covering
all or a part of the gap size with the speaker body structure frame.
[0019]
On the other hand, on the entire inner circumference of the frame of the speaker body structure,
a sound absorbing flexible membrane is also provided in parallel with the diaphragm in a width
covering all or part of the void size. It is attached and has a structure in which it is overlapped
with a film attached to a diaphragm. At this time, the film attached to the diaphragm and the film
attached to the frame are merely in contact with each other in a flexible manner, with only
positional contact or overlap. In this way, the vibration of the diaphragm can be restrained by the
air flow passage without being restrained even at large amplitude, and the air vibration can be
absorbed by the sound absorbing flexible film. Thus, the reproduction sound on the front and
back of the diaphragm is effectively blocked.
[0020]
Although the present invention includes that the drive coil winding shape is a polygon such as
triangle, rectangle, pentagon or the like or a circle, the case where the winding shape of the drive
coil is a rectangle will be described as one embodiment. FIG. 6 is an overall view of the
embodiment. However, in order to make the point of the present invention clearer, the magnetic
circuit and the structure for supporting it are omitted, and FIG. 7 shows the relationship between
the structure of the magnetic circuit and the drive coil.
[0021]
In FIGS. 6 and 7, reference numeral 1 denotes a drive coil, which is wound around a rectangular
winding frame 2 which is a part of a crosspiece 3 attached in the form of a well to reinforce the
11-05-2019
6
diaphragm 6. The magnetic circuit is mounted such that the major part of the drive coil in the
longitudinal direction is at the middle position of the magnetic gap shown in FIG. In FIG. 7, 4 is a
magnet, and when its polarity (N, S) is at the position shown in FIG. 7 with respect to the
longitudinal direction portion 1 ′ of the drive coil 1 of FIG. For the longitudinal part 1 ′ ′, two
magnetic circuits are mounted so as to be opposite in polarity to the position shown in FIG.
Numeral 5 in FIG. 7 is a yoke for making a magnetic air gap.
[0022]
In FIG. 6, reference numeral 6 denotes a flat diaphragm, in which the winding frame 2 of the
drive coil is fixed, and when an electric signal is input to the drive coil 1 from its end 1a, 1b,
vibration of the drive coil 1 is generated. Is transmitted to the flat diaphragm 6. The vibration
system consisting of the drive coil 1, the winding frame 2 and the plane vibration plate 6 fixes
one end of the four flat plate plate springs 7 to the four corners of the winding frame 2 in
parallel with the vibration plate 6 The end is fixed to the speaker body structure frame 8 and
supported radially from four directions.
[0023]
An embodiment of the flat plate spring 7 is shown in FIG. With the center line in the longitudinal
direction of the short resin plate of 0.5 mm in thickness as the target axis, three U-shaped, Lshaped, and inverted L-shaped cuts (slits) are arranged. Further, the side fixed to the winding
frame 2 is at the right end at the right end so as to be along the corner of the crosspiece 3 of the
well girder.
[0024]
Next, the film 9 for covering the gap between the diaphragm 6 and the speaker body structure
frame 8 will be described. In FIG. 8 showing a cross section of FIG. 6, a sound absorbing flexible
film 9 a is pasted on the entire circumference of the end of the flat diaphragm 6 in parallel to the
diaphragm 6 so as to cover the air gap. In addition, a sound absorbing flexible film 9b is adhered
on the entire inner circumference of the speaker body structure frame 8 so as to cover the air
gap in parallel with the diaphragm 6 and to overlap the film 9a. It should be noted that in FIG. 8
the air gap is intentionally shown to show that the membranes 9a and 9b are simply flexible and
overlapping and not integral. Moreover, in the case of a material with high sound absorption, it is
11-05-2019
7
only necessary to abut on each other without overlapping. In FIG. 8, the positional relationship of
the drive coil 1, the winding frame 2, the plate spring 7, and the vibration plate 6 in the vibration
direction is also shown. However, the positional relationship between the films 9a and 9b may be
upside down as illustrated.
[0025]
In the embodiment of the present invention, the diaphragm 6 is made of a lightweight lumber
balsa of 1.5 mm thickness and is a 78 mm × 148 mm rectangular diaphragm, and the flat plate
spring 7 is 0.5 mm thick. A 12 mm × 39 mm polycarbonate resin plate with the incision shown
in FIG. 5 is used to support the vibration system, and flexible films 9a and 9b are made of
diaphragms and spi Covering an air gap of about 9 mm between the frame of the car body
structure.
[0026]
As described above, the flat plate spring having the plurality of non-continuous cuts (slits) shown
in FIG. 5 supports the drive coil or the corner portion of the winding frame thereof. In addition,
the gap between the entire circumference of the plane diaphragm and the speaker body structure
frame is covered with a sound absorbing flexible film to sufficiently guarantee the freedom of the
vibration system in the direction of vibration. It is possible to faithfully reproduce a large audio
frequency range of a dynamic range with a single speaker and a relatively small-area diaphragm.
[0027]
Brief description of the drawings
[0028]
1 illustrates the principle of Fleming left hand, which is the principle of operation of the speaker.
[0029]
2 illustrates the mode of vibration of the plate spring.
[0030]
FIG. 3 shows a state in which the vibrating structure is supported at both ends by a flat plate
spring.
11-05-2019
8
[0031]
FIG. 4 shows a state in which the vibrating structure is supported at both ends by a bent plate
spring.
[0032]
FIG. 5 illustrates the shape as an embodiment of a flat plate spring which is an element of the
present invention.
[0033]
6 is a perspective view showing the entire embodiment of the present invention.
[0034]
7 is a diagram showing a part of the magnetic circuit and showing the relative position of the
magnetic circuit and the drive coil.
[0035]
8 is a cross-sectional view of FIG.
[0036]
Explanation of sign
[0037]
Reference Signs List 1 drive coil 2 winding frame 6 flat diaphragm 7 flat plate plate spring 8
speaker body structure frame 9 sound absorbing flexible film
11-05-2019
9
Документ
Категория
Без категории
Просмотров
0
Размер файла
18 Кб
Теги
jph0884395
1/--страниц
Пожаловаться на содержимое документа