close

Вход

Забыли?

вход по аккаунту

?

JP2005333608

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 JP2005333608
The present invention provides a flat speaker having a cavity structure and degradation of
directivity characteristics, each having a simple structure. A diaphragm comprising a coil pattern
printed on a film and a plate-like magnet disposed on the opposite surface of the diaphragm. A
plurality of through holes are disposed in the plate-like magnet, and the plurality of penetrations
are formed. At least a part of the hole is formed wider at the anti-diaphragm side than at the
diaphragm side. [Selected figure] Figure 5
Flat speaker
[0001]
The present invention relates to improvements in flat speakers.
[0002]
A flat speaker as shown in FIG. 1 is known as one type of speaker.
In this flat speaker, as shown in FIG. 2, a diaphragm B on which a voice coil A is printed on a
polymer film is used, and magnets C and C disposed at the front and back in the thickness
direction are magnetic gaps. The B is vibrated to transmit sound, and a large number of sound
removal holes D are disposed in the magnets C and C at equal intervals.
11-05-2019
1
[0003]
Such flat speakers can be made thinner than conventional speakers, and sound is emitted as
plane waves, so they are not tired even if they are listening, and they have less reflected waves,
so they have the advantage of low sound attenuation. However, since the magnet has a
considerable thickness and a vertical cylindrical shape perpendicular to the plate surface is
formed as the sound hole D, it has a characteristic peak due to the cavity effect as shown in FIG.
There was a problem to occur.
[0004]
In addition, because of the cylindrical sound release hole D positioned perpendicular to the
diaphragm, the directivity characteristics (positions shifted by 30 ° and 60 °) at positions
deviated from on the diaphragm axis deteriorate significantly There is a problem that it is easy to
do, especially in the high frequency range.
As a countermeasure, it is possible to eliminate the magnet on the front surface of the diaphragm
and operate only with the magnet on the back surface, but there is a problem that the magnetic
flux density is lowered and sufficient sound pressure can not be secured. Japanese Patent
Application Publication No. 2001-333493
[0005]
The present invention has been made to solve the above-mentioned problems, and its object is to
provide a flat speaker which has been able to improve the cavity effect and the deterioration of
the directional characteristics while having a simple structure. It is to do.
[0006]
In order to achieve the above object, the present invention comprises a diaphragm in which a coil
pattern is printed on a film, and a plate-like magnet disposed on the opposite surface side of the
diaphragm, and the plate-like magnet has a plurality of through holes. A fundamental feature of
the flat speaker arranged is that at least a part of the plurality of through holes is formed such
that the diameter of the anti-vibration plate is wider than the diameter on the vibration plate side.
[0007]
11-05-2019
2
According to the present invention, at least a part of the through holes as the sound release holes
arranged in a large number in the magnet, the opening area at the position emitting the sound
relative to the opening area of the part near the diaphragm is relative Because of the large size,
even if the magnet is thick, cavity resonance at the front of the diaphragm can be avoided, and
the characteristic runaway phenomenon due to the cavity effect can be eliminated.
In addition, since the aperture area at the position emitting the sound is large, deterioration of
the directivity characteristic at the position (30 °, 60 °) deviated from the diaphragm axis is
reduced, and high frequency band is less likely to be attenuated. Effect is obtained.
[0008]
Preferably, magnets are disposed on both sides of the diaphragm, and at least one side of the
magnets on both sides is provided with the through holes whose diameter on the opposite side to
the diaphragm is increased.
According to this, it is possible to obtain an excellent effect that the cavity effect can be
prevented and the directional characteristics can be prevented from being deteriorated while
securing a sufficient sound pressure.
[0009]
The through hole in which the aperture on the side opposite to the diaphragm is formed wider
than the aperture on the diaphragm side has a tapered cross section. As a result, it is possible to
ensure smooth sound spread while avoiding the occurrence of the cavity effect. In the present
invention, the “tapered shape” includes not only the case where the whole is inclined but also
the case where a part of the cross section is vertical.
[0010]
The tapered shape includes both the case of being symmetrical with respect to a plane passing
through the axis of the opening on the diaphragm side and the case of being asymmetrical.
11-05-2019
3
According to the former, it is possible to obtain equal sound pressure in each direction without
directivity. According to the latter, the sound pressure is lowered at a portion where the taper
angle is reduced including zero, and the sound pressure is increased at a portion where the taper
angle is increased, so that directional characteristics with high sound pressure in a specific
direction are intentionally obtained. it can. Therefore, for example, when used as a vehiclemounted speaker and mounted on a door etc., the speaker attachment position is below from the
listening point, but the angle of the tapered hole of the through hole disposed in the speaker is
large upward By doing this, the sound pressure on the upper side can be raised, and the listening
effect can be raised.
[0011]
Hereinafter, embodiments of the present invention will be described with reference to the
attached drawings. 4 to 6 show a first embodiment of a flat loudspeaker according to the
invention. 1, 1 'is a plate-like or thin box-like frame, and ridges 10, 10' are formed on the
periphery of each frame, and these ridges 10, 10 'are flattened by polymerization and fixing. Shaped board is constructed.
[0012]
Reference numerals 2 and 2 'denote plate-like magnets disposed and fixed in the respective
frames 1 and 1', each of which is a sintered magnet or a bonded magnet formed by injection
molding, and has a plurality of strip plate-like unit magnets having perpendicular magnetic poles.
The portions 2a are arranged on the same plane such that adjacent portions have opposite
polarities. As for the magnetic poles in the upper and lower magnets 2 and 2 'in the drawing, the
N poles and the S poles face each other.
[0013]
Reference numeral 3 denotes a diaphragm (diaphragm film) which is held or free from the
magnetic pole faces 20 and 20 'of the magnets 2 and 2' by a predetermined distance, and a
plurality of diaphragms are arranged on one side (or both sides) of the polymer film 30. The
voice coil 6 is applied in a printing manner. The planar pattern of each voice coil 6 is optional,
such as a single stroke frame or spiral, but in any case, it is necessary to be placed in a magnetic
field formed by magnetic poles of different polarities adjacent to each other.
11-05-2019
4
[0014]
Reference numerals 4 and 4 'are buffer sheets stretched between the diaphragms 3 and 3 and
the magnets 2 and 2', and are made of non-woven fabric or Japanese paper, etc. It also doubles
as a dustproof device that blocks entry. A gap is provided between the buffer sheet 4 or 4 'and
the diaphragm 3, and this gap prevents the vibration of the diaphragm 3 from being disturbed,
and suppresses the contact even when the diaphragm 3 is largely vibrated, noise To prevent the
occurrence of
[0015]
The magnets 2 and 2 'are provided with through holes 21 and 21' as sound release holes at
regular intervals, and the thickness of the frames 1 and 1 'corresponding to the through holes 21
and 21'. Through the direction, the sound removal holes 11, 11 'are disposed. Although this is
similar to the conventional one, in the first embodiment, the required range (here, the entire
cross section) of the through hole 21 of the magnet 2 on the front side is the opening 210 on the
side closer to the diaphragm 3 Is relatively small in diameter, and has a tapered shape in which
the cross-sectional area is gradually enlarged such that the opening 211 on the side opposite to
the diaphragm becomes relatively large. In this embodiment, the through hole 21 'of the rear side
magnet 2' has a straight cylindrical shape in which the opening 210 'and the opening 211 on the
side opposite to the vibration plate have the same diameter. Although the sound holes 11 and 11
'of the frame 1 have a straight shape corresponding to the opening 211, they may have a tapered
shape.
[0016]
FIG. 7 shows a second embodiment of the present invention, in which the required range (here,
the entire cross section) of the through holes 21 and 21 'of both magnets 2 and 2' on the front
side and the back side is the diaphragm 3 respectively. The cross-sectional area is gradually
enlarged so that the openings 210 and 210 'on the side closer to the side have a relatively small
diameter, and the openings 211 and 211' on the side opposite to the diaphragm have a relatively
large diameter. There is.
[0017]
11-05-2019
5
FIGS. 8 and 9 show a third embodiment of the present invention, in which the cross-sectional
required range of the through hole 21 of the front side magnet 2 is relatively small in diameter,
with the opening 210 on the side closer to the diaphragm 3 having a relatively small diameter.
Similar to the first embodiment, the cross-sectional area is gradually enlarged so that the opening
211 on the diaphragm side has a relatively large diameter, which is the same as in the first
embodiment. While the tapered shape of the hole 21 is symmetrical to the plane M passing
through the axial center of the opening 210 on the side closer to the diaphragm 3, in this third
embodiment, the tapered shape of the through hole 21 is the opening 210 It is asymmetric to the
plane M passing through the axis of.
That is, as shown in FIG. 9, a portion on the circumference of the hole wall is used as the first
shape portion 21a having a zero or small taper angle, and the portion on the opposite side is an
opening on the anti-diaphragm side The second diameter-shaped portion 21 b is enlarged in
diameter toward 211. The other configuration is the same as that of the first embodiment, so the
same reference numerals are given to the same parts, and the description will be incorporated.
[0018]
FIG. 10 shows a fourth embodiment of the present invention, in which the taper shape of the
through hole 21 of the front side magnet 2 is obtained by using a first shape portion 21a having
a zero or small taper angle and an opening on the anti-diaphragm side. The asymmetrical shape
is formed of the second diameter-shaped portion 21b whose diameter is enlarged toward 211,
and the through-hole 21 'of the back side magnet 2' also has a first shape portion 21a 'whose
taper angle is zero or small. It is configured in an asymmetrical shape including a second
diameter-shaped portion 21b 'whose diameter is enlarged toward the opening 211' on the side
opposite to the vibration plate. The other configuration is the same as that of the first
embodiment, so the same reference numerals are given to the same parts, and the description
will be incorporated.
[0019]
The above embodiments are just several examples of the present invention, and the present
invention is not limited to these. 1) In the case of the asymmetric shape, as shown in FIG. 11A,
when the first shape portion 21a has a taper angle of zero, the taper angle of the first shape
portion 21a has a second diameter shape as shown in FIG. It includes any case that is relatively
11-05-2019
6
smaller than the portion 21 b (21 b ′). However, the first shape portion 21 a and the second
diameter shaped portion 21 b (21 b ′) may be in any direction of 360 degrees. 2) The planar
shape of the through hole 21 is not limited, and various shapes such as oval or oval as shown in
FIG. 11 (c), oval shape as shown in FIG. 3) The present invention is not limited to the case where
all the through holes 21 or 21 'are tapered (including the case of having a slope of zero in a part),
and the usage condition of the speaker, the direction in which sound is desired, etc. Accordingly,
for example, only one through hole 21 or 21 'may be tapered while the other may be a straight
cylinder, for example, every other row, only in the central region, etc. 4) In addition, in the case
where the through holes 21 or 21 'are tapered (including the case of having a slope of zero at a
part), the one symmetrical to the plane passing through the axis of the opening on the diaphragm
side An asymmetry may be combined with the plane passing through the axis of the opening of.
[0020]
To explain the operation of the embodiment, when power is supplied to the voice coil 6 through
the input terminal, the voice coils 6 are placed in the magnetic field formed by the unit magnet
parts 2a and 2a adjacent to each other, so that they are adjacent to each other. When current in
the same direction flows on the adjacent sides of the voice coil, the diaphragm 3 receives an
electromagnetic force according to Fleming's left-hand rule, and the diaphragm 3 forms a voice
coil with a gap between the magnets 2 and 2 '. It vibrates by the flowing audio current and is
emitted as sound from the through holes 21 and 21 'of the magnets 2 and 2'.
[0021]
At this time, in the first embodiment, the through hole 21 of the magnet 2 on the front side has a
horn shape tapered from the portion close to the diaphragm, and the opening area at the position
emitting the sound is large. Even if the magnet 2 is thick, cavity resonance is avoided, and
generation of a midrange peak due to the cavity effect can be eliminated.
In the second embodiment, since both the through holes 21 and 21 'of the magnets 2 and 2' on
the front side and the rear side have a horn shape, cavity resonance can be further avoided. FIG.
12 (a) shows the result of measuring the relationship between the frequency in the first
embodiment of the present invention and the sound pressure under 1 W input conditions at 1 m,
and the mid-range peak is eliminated as compared with the conventional type of FIG. It is
understood that it is done.
[0022]
11-05-2019
7
Further, according to the present invention, since the through hole 21 of the magnet 2 on the
front side has a horn shape tapered from the portion close to the diaphragm, the attenuation of
the sound pressure at the position deviated from the diaphragm axis is reduced. Can. FIG. 8 (b)
shows the measurement results at the positions where the angles of 30 ° and 60 ° are shaken,
which is a directional characteristic in which the attenuation of the high range is remarkably
improved as compared with the conventional through hole type of FIG. Know that Therefore, it is
possible to obtain a long plane wave with a powerful reaching distance.
[0023]
In the third embodiment, since the through hole 21 of the magnet 2 on the front side is
asymmetrical to the plane passing through the axis of the opening on the diaphragm side, the
sound pressure decreases in the portion 21a where the taper angle is reduced Since the sound
pressure is increased in the portion 21b where the taper angle is increased, the sound pressure
in the specific direction can be increased. Therefore, the cavity effect can be improved and the
directivity can be improved by making the direction of the portion 21b with the increased taper
angle correspond to the position where the speaker is placed and the listening direction.
[0024]
It is a perspective view which shows the external appearance of the conventional flat speaker. It
is a fragmentary sectional view in alignment with the II-II line of FIG. It is a diagram which shows
the characteristic (0 degree, 30 degrees, 60 degrees) of the conventional flat speaker. FIG. 1 is a
partially cutaway perspective view of a first embodiment of a flat loudspeaker according to the
invention; FIG. 5 is a partial cross-sectional view along the line V-V in FIG. 4. It is a partial
perspective view which shows the relationship between a magnet and a diaphragm. FIG. 5 is a
partial cross-sectional view of a second embodiment of a flat loudspeaker according to the
invention; FIG. 7 is a partially cutaway perspective view of a third embodiment of a flat
loudspeaker according to the invention; It is a fragmentary sectional view of a 3rd example. It is a
fragmentary sectional view of a 4th example. (A), (b) (c) (d) is a top view which shows the
example of a shape of the through-hole in 3rd, 4th Example, respectively. (A) is a diagram
showing the characteristic (0 °) of the first embodiment, and (b) is a diagram showing the
characteristic (30 °, 60 °).
11-05-2019
8
Explanation of sign
[0025]
2, 2 'plate-like magnet 3 diaphragm 21, 21' through hole 21a, 21a 'first shape portion 21b, 21b'
second shape portion 210, 210 'opening on diaphragm side 211, 211' anti-diaphragm Side
opening
11-05-2019
9
Документ
Категория
Без категории
Просмотров
0
Размер файла
18 Кб
Теги
jp2005333608
1/--страниц
Пожаловаться на содержимое документа