close

Вход

Забыли?

вход по аккаунту

?

JP2008228016

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 JP2008228016
An object of the present invention is to provide a condenser headphone which can be
miniaturized and reduced in weight by making it possible to obtain a high voltage audio signal
without using a step-up transformer. A capacitor type electro-acoustic conversion unit generates
vibration by vibrating a diaphragm 6 by changing a capacitor capacity between the diaphragm 6
and fixed electrodes 7 and 8 opposed to the diaphragm 6 according to an audio signal.
Condenser headphones with. A signal voltage generated by the piezoelectric element 4
corresponding to an audio signal, including a giant magnetostrictive element 2 around which a
coil 3 for inputting an audio signal is wound, and a piezoelectric element 4 joined to one end of
the giant magnetostrictive element 2 Is applied between the diaphragm 6 and the fixed
electrodes 7 and 8. [Selected figure] Figure 1
コンデンサーヘッドホン
[0001]
The present invention relates to a condenser headphone that vibrates a diaphragm to generate
sound by changing a capacitor capacity between the diaphragm and a fixed electrode opposed to
the diaphragm according to an audio signal. In addition to using a capacitor structure, it is
characterized in that a giant magnetostrictive element and a piezoelectric element are added
thereto.
[0002]
The condenser headphone is driven by applying an audio signal of a high voltage of about 100 V
04-05-2019
1
effective value between the diaphragm and the fixed electrode facing each other.
Since a normal audio signal is a signal of a relatively low voltage, it is necessary to boost the
audio signal level to a high voltage of about 100 V effective value, and in general, it is necessary
to boost the audio signal using a step-up transformer. It has become. In order to boost the
voltage of a normal audio signal to a high voltage of about 100 V, it is necessary to increase the
transformation ratio to, for example, 1:70. The frequency of the voice signal is about 20 Hz to 20
kHz, and boosting the voice signal in such a frequency band using the step-up transformer with a
large transformation ratio as described above has a problem that the frequency response is
degraded. In addition, since a transformer with a large transformation ratio becomes large and
heavy, it becomes a factor that hinders downsizing and weight reduction of headphones.
[0003]
The present invention solves the problems of the conventional condenser headphone as
described above by adding a giant magnetostrictive element and a piezoelectric element. There
are crystal type earphones and pickups for reproducing records as those using a piezoelectric
element as an electroacoustic transducer, but in recent years, such crystal type electroacoustic
transducers have been hardly used. In recent years, speakers or acoustic devices have been
proposed that perform electroacoustic conversion using the magnetostriction phenomenon of a
giant magnetostrictive element. Hereinafter, the prior art of a speaker or an acoustic device using
a giant magnetostrictive element will be described.
[0004]
In Patent Document 1, one end is fixed to a yoke forming a magnetic path in a closed bottomed
cylindrical shape and a lid portion of the yoke, the other end is formed as a free end, and is
disposed in the cylindrical direction of the yoke to change the magnetic field A magnetostrictive
element generating displacement according to the coil, a coil disposed around the
magnetostrictive element in the yoke and generating a magnetic field corresponding to a signal
supplied from the outside, one end contacting the free end of the magnetostrictive element, The
other end of the bottom of the yoke penetrating the center hole is disposed to transmit the
displacement of the giant magnetostrictive element to an external object, and has a vibrating rod
having a ridge at the middle, a ridge provided on the vibrating rod and the yoke In the state that
the other end of the vibrating rod is placed on the external object so as to stand on its own, and
the rubber elastic body disposed between the bottom of the body, the super magnetostrictive
element is loaded via the yoke, Enables displacement of the giant magnetostrictive element to an
external object Supermagnetostriction speaker and a body portion for transmitting has been
04-05-2019
2
proposed.
[0005]
In patent document 2, it has a vibration apparatus arrange | positioned under the floor or road of
the substantially plate-like body which can be vibrated to thickness direction, A floor or a floor
surface or a road is vibrated by this vibration apparatus. A speaker capable of generating sound
from a road surface, comprising a magnetostrictive member as a vibrating device, and a
substantially rod-like magnetostrictive rod fixed at one end to a mass member, and a coil
disposed around the magnetostrictive rod, Speakers have been proposed.
[0006]
In Patent Document 3, a magnetostrictive element, a magnetic field generating coil generating a
magnetic field in the expansion / contraction direction of the magnetostrictive element, a support
member movably supporting both ends of the magnetostrictive element, and DC magnetic fields
of different polarities are applied to both ends of the magnetostrictive element. A
magnetostrictive speaker device has been proposed which is capable of wide-band reproduction
and includes a magnetic circuit to be used and a diaphragm fixed to one end of the
magnetostrictive element.
[0007]
JP, 2006-311255, A JP, 2005-277471, A JP, 2004-363967, A
[0008]
The speakers described in Patent Documents 1 to 3 use the magnetostrictive effect of the giant
magnetostrictive element for direct electroacoustic conversion, and do not use the giant
magnetostrictive element for the condenser headphone as in the present invention, and
Moreover, neither a giant magnetostrictive element nor a piezoelectric element is used.
[0009]
The present invention solves the problems of the conventional condenser headphone as
described above by using the super magnetostrictive element and the piezoelectric element in
combination with the capacitor structure in the electroacoustic transducer, and a high voltage
audio signal without using a boost transformer It is an object of the present invention to provide
a condenser headphone capable of achieving downsizing and weight reduction.
04-05-2019
3
[0010]
According to the present invention, there is provided a condenser headphone including a
condenser type electro-acoustic conversion unit which vibrates a diaphragm to generate sound
by changing a capacitor capacity between the diaphragm and a fixed electrode opposed thereto
according to an audio signal. A signal generated by the piezoelectric element corresponding to
the audio signal, comprising: a giant magnetostrictive element in which a coil for inputting an
audio signal is wound; and a piezoelectric element joined to one end of the giant magnetostrictive
element The main feature is to apply a voltage between the diaphragm and the fixed electrode.
[0011]
When an audio signal is input to the coil, a magnetic field corresponding to the audio signal is
generated in the coil, and mechanical stress is generated in the giant magnetostrictive element in
response to the magnetic field.
This mechanical stress is transmitted to the piezoelectric element, and a high voltage signal
corresponding to the voice signal is generated at both ends of the piezoelectric element.
The high voltage audio signal is applied to a diaphragm and a fixed electrode constituting a
capacitor type electro-acoustic conversion unit, and the diaphragm vibrates corresponding to the
audio signal, is converted to audio, and is output.
The audio signal input to the coil is a low voltage signal, and this signal is converted to
mechanical stress by the magnetostrictive element, and this mechanical stress is converted to a
high voltage audio signal by the piezoelectric element to form a capacitor type electroacoustic
conversion unit. It will be input and a capacitor electroacoustic transducing unit will be driven.
Therefore, unlike the conventional condenser headphones, it is not necessary to use a step-up
transformer with a high transformation ratio, and it is possible to obtain compact and lightweight
condenser headphones.
[0012]
04-05-2019
4
Hereinafter, embodiments of a condenser headphone according to the present invention will be
described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a frame formed in a rectangular frame shape.
The frame 1 is made of a rigid body such as metal.
Inside the frame 1, the giant magnetostrictive element 2 and the piezoelectric element 4 are
joined in their respective length directions and arranged in the long side direction of the frame 1,
and the giant magnetostrictive element 2 and the piezoelectric element 4 joined in series. It is
held by the frame 1. The giant magnetostrictive element 2 and the piezoelectric element 4 have a
cylindrical shape with the same diameter, and have a columnar shape in which the giant
magnetostrictive element 2 and the piezoelectric element 4 are continuous. The coil 3 is wound
an appropriate number of times on the giant magnetostrictive element 2 with the core as a core.
The coil 3 may be wound around a bobbin, and the super magnetostrictive element 2 may be
inserted into the center hole of the bobbin. A signal source 5 is connected to the coil 3, and an
audio signal is input from the signal source 5. The voltage level of the audio signal input to the
coil 3 is a low voltage signal level equivalent to the voltage level input to a commercially
available headphone.
[0013]
When an audio signal is input to the coil 3, a magnetic field corresponding to the audio signal is
generated in the coil 2, and the magnetostrictive element 2 expands and contracts in response to
the magnetic field by its magnetostrictive action. The dimensional change of the giant
magnetostrictive element 2 due to the external magnetic field is referred to as the Joule effect.
Since the giant magnetostrictive element 2 is joined in series with the piezoelectric element 4 and
held between the frames 1, the dimensional change is limited, and mechanical stress is generated
inside the giant magnetostrictive element 2. This stress is transmitted to the piezoelectric
element 4 to generate a high voltage signal at both ends of the piezoelectric element 4 in
response to the stress and thus to the audio signal. By inputting the high-voltage audio signal
generated by the piezoelectric element 4 to the capacitor type electro-acoustic conversion unit,
the capacitor type electro-acoustic conversion unit can be driven. The embodiment shown in FIG.
1 can drive the capacitor-type electro-acoustic conversion unit more efficiently, rather than
simply inputting the high-voltage audio signal generated by the piezoelectric element 4 into the
capacitor-type electro-acoustic conversion unit. The structure of the capacitor type
04-05-2019
5
electroacoustic conversion unit, the structure of the piezoelectric element 4 and the electrical
connection are further devised. This will be explained concretely.
[0014]
As seen in a condenser microphone, a condenser type electro-acoustic conversion unit is mainly
composed of a diaphragm made of a thin film that vibrates according to voice and a fixed
electrode disposed opposite to the diaphragm with a predetermined gap. When a capacitor is
formed by the diaphragm and the fixed electrode and the voltage applied between the diaphragm
and the fixed electrode is changed, the diaphragm vibrates according to the change of the
voltage, and a sound is generated. In the embodiment shown in FIG. 1, the configuration of the
capacitor type electroacoustic conversion unit comprises one diaphragm 6 and a pair of fixed
electrodes 7 and 8 disposed on both sides of the diaphragm 6. . The diaphragm 6 is circular, and
its peripheral portion is supported by the diaphragm support 9. In FIG. 1, the diaphragm 6 and
the fixed electrodes 7 and 8 are shown in a longitudinal cross section. The pair of fixed
electrodes 7 and 8 are disposed with a predetermined gap with respect to the diaphragm 6. The
diaphragm 6 and the fixed electrodes 7 and 8 are incorporated in a unit case (not shown) so as to
maintain the relative positional relationship as described above.
[0015]
The piezoelectric element 4 is configured to be electrically connected in series by laminating a
plurality of piezoelectric elements, so that signals are output from both ends of the laminated
piezoelectric element 4. Output terminals are provided at both ends of the piezoelectric element
4. Therefore, the output voltages of the individual piezoelectric elements are added and output
from the output terminals at both ends. In the embodiment shown in FIG. 1, an intermediate
terminal is provided at the center of the stacked piezoelectric elements. Further, in the
embodiment shown in FIG. 1, the piezoelectric elements 41 are formed by laminating a plurality
of piezoelectric elements also from the center of the laminated piezoelectric elements at one end
side, and the piezoelectric element group 41 is formed. A piezoelectric element group 42 is
formed by laminating a plurality of piezoelectric elements on the other end side of the
piezoelectric element as well.
[0016]
04-05-2019
6
The output terminal of one piezoelectric element group 41 is electrically connected to the fixed
electrode 7 by the lead wire 11, and the output terminal of the other piezoelectric element group
42 is electrically connected to the fixed electrode 7 by the lead wire 12. In this example, the lead
wire 11 side is a minus pole, and the lead wire 12 side is a plus pole. The intermediate terminal
of the piezoelectric element 4 is electrically connected to the diaphragm 6 through the lead wire
13. In the example shown in FIG. 1, a battery 14 is connected in the middle of the lead wire 13 as
a power supply for applying a polarization voltage to the diaphragm 6. The power supply battery
14 is connected to apply a positive voltage to the diaphragm 6. However, when the capacitor
type electroacoustic conversion unit is an electret type, it is not necessary to apply a polarization
voltage, so the lead wire 13 is directly connected to the diaphragm 6 without connecting the
battery 14.
[0017]
When an audio signal is input from the signal source 5 to the coil 3, a magnetic field
corresponding to the audio signal is generated in the coil 3. Although the giant magnetostrictive
element 2 tries to change the dimension according to the change of the magnetic field by the
Joule effect, since the giant magnetostrictive element 2 is sandwiched in the frame 1 together
with the piezoelectric element 4, the dimensional change is restricted. Cause mechanical stress.
This mechanical stress is transmitted to the piezoelectric element 4, and as a result, a high
voltage signal corresponding to the audio signal is generated at both ends of the piezoelectric
element 4. By applying this high voltage signal between the diaphragm and the fixed electrode
constituting the capacitor type electroacoustic conversion unit, the diaphragm is vibrated
corresponding to the audio signal, and the sound wave is radiated from the diaphragm. can do.
[0018]
In the embodiment shown in FIG. 1, by laminating a plurality of piezoelectric elements 4, the
output voltage as the piezoelectric element 4 can be output as a voltage applied in series, and it
is easy to obtain a high voltage output It has a structure. Further, the piezoelectric element 4 is
divided into two piezoelectric element groups 41 and 42, and an intermediate terminal is
provided in the middle of these piezoelectric element groups and connected to the diaphragm 6.
The capacitor type electroacoustic conversion unit is composed of the diaphragm 6 and a pair of
fixed electrodes 7 and 8 disposed opposite to each other with the diaphragm 6 interposed
therebetween, and the terminal of one end of the piezoelectric element group 41 is fixed. The
terminal of the other end of the piezoelectric element group 42 is connected to the fixed
electrode 8 in the electrode 7. Therefore, the audio signal is boosted to a high voltage by the
04-05-2019
7
boosting means including the giant magnetostrictive element 2 and the piezoelectric element 4
and applied to the pair of fixed electrodes 7 and 8, and the diaphragm 6 is configured with the
fixed electrode 7. And the fixed electrode 8 are driven by both of the capacitor structures. Thus,
since the diaphragm 6 is efficiently driven by the fixed electrodes 7 and 8 sandwiching the
diaphragm 6, sound waves with sufficiently high sound pressure can be output.
[0019]
Even if the audio signal input from the signal source 5 is a general low voltage signal, it is
boosted to a high voltage by the magnetostrictive element 2 and the piezoelectric element 4 and
has a high transformation ratio like a conventional capacitor type headphone There is no need to
use a step-up transformer, and a compact and lightweight condenser headphone can be obtained.
[0020]
FIG. 1 is a structural view and a connection diagram schematically showing an embodiment of a
condenser headphone according to the present invention.
Explanation of sign
[0021]
Reference Signs List 1 frame 2 giant magnetostrictive element 3 coil 4 piezoelectric element 5
signal source 6 diaphragm 7 fixed electrode 8 fixed electrode 41 piezoelectric element group 42
piezoelectric element group
04-05-2019
8
Документ
Категория
Без категории
Просмотров
0
Размер файла
17 Кб
Теги
jp2008228016
1/--страниц
Пожаловаться на содержимое документа