close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JPH03195295

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 JPH03195295
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
active noise canceller having a function of actively canceling external noise. 2. Description of the
Related Art It is known in the prior art as an active noise canceller, for example, as described in
U.S. Pat. No. 4,455,675. The active noise canceller outputs, from the muffling speaker,
cancellation sound in reverse phase to the input sound from the monitoring microphone, and
muffles external noise by canceling out the external noise and the cancellation sound. However,
according to this prior art, there is a problem that it is difficult to install a monitoring
microphone so as to input the cancellation sound without bias and not to disturb the sound field
of the cancellation sound. In addition, since the monitor microphone needs to receive external
noise as well, it needs to be spaced to a certain extent from the muffling speaker, which causes a
phase delay and causes howlink. Therefore, the applicant of the present application has proposed
an active noise canceller (hereinafter referred to as "precedingly referred to hereinafter as
Japanese Patent Application No. 1-44790") as means for solving the above conventional
problems by means of feedback control or an unnecessary simple control circuit. Called
technology). In this prior art, a monitor microphone is provided at a position where the
cancellation sound and the cancellation sound cancel each other, by providing an auxiliary spino
that emits an auxiliary cancellation sound in phase with the cancellation sound on the negative
pressure surface of the muffling speaker. Only external noise is input to the microphone.
(Problem to be Solved by the Invention) However, in this prior art, the space on the muffling
spino] side and the space on the secondary speaker side are not necessarily acoustically equal.
That is, the space shape and space volume are not equal, and in particular, when this active noise
canceller is of the type worn on the head of a person, the muffling speaker side space where the
cancellation sound is emitted is the person's head and device The secondary speaker side space
on the opposite side is formed only by the case, and the shape and volume are different, and the
15-04-2019
1
material of the space forming part is different. Therefore, a phase shift occurs in the reflected
sound of each of the sounds emitted from the two loudspeakers generated on the wall of the rain
space, and the reflected sound only cancels out at the position of the monitor microphone,
resulting in a residual pedestal. . Therefore, by misidentifying this residual block input from the
monitoring microphone as an extraneous sound, the muffling speaker amplifies an unnecessary
sound as a cancellation sound, or the residual block becomes a howlink cycle. There was a
problem that howling was caused by coming in.
The present invention has been made focusing on the above-mentioned problems, and by
eliminating the residual base of the reflected sound, it is possible to eliminate unnecessary
amplification of the sound and howlink, thereby enhancing the silencing effect.・ To develop a
noise canceller. (Means for Solving the Problems) In order to solve the above problems, in the
active noise canceller of the present invention, there is provided a muffling speaker which emits
canceling sound of opposite phase to the muffling target sound from the positive or negative
side, and the muffling The sub-speaker, which emits a sub-cancelling sound in the same phase as
the canceling sound from one side to the other side of the positive and negative sides of the
speaker, and the sound radiated from both speakers cancel each other out. While outputting a
cancellation sound generation signal for causing the cancellation speaker to emit a cancellation
sound to the muffling speaker based on the monitor microphone for inputting the external sound
including the sound and the input sound from the monitor microphone, the sub cancellation
sound is emitted to the sub speaker A noise cancellation circuit for outputting an auxiliary
cancellation sound generation signal to cause the noise and muffling of the front surface of one
of the positive and negative sides of the muffling speaker A speaker side space, and Haujinku
forming symmetrically and secondary spin force side space of the front surface of the positive
and negative other surface of the sub-speaker are provided. (Operation) In the active noise
canceller of the present invention, the cancellation sound of the opposite phase to the sound to
be muted such as noise is emitted from the muffling speaker, and the muffling action cancels the
muffling sound. It is possible to input only the sound to be muted without being affected by the
emitted sound, and it is possible to prevent the generation of howlink due to the re-input of the
phase delay cancellation sound, for motor The microphone can be arranged close to the muffling
speaker to improve the muffling performance, and the microphone for the motor is installed at a
position away from the radiation front of the pressure member surface of the vibrating member
of the muffling loudspeaker to improve the muffling performance in high frequency region About
the point which can be made to be the same as prior art, explanation is omitted. Furthermore, in
the active noise canceller according to the present invention, since the Hausink that
symmetrically forms the muffling speaker side space and the sub speaker side space is provided,
the shape and volume of the rain space are uniform, and reflection of the sound radiated from
both speakers There is no phase shift in the sound, and furthermore, if the materials of the howsink forming the rain space are made equal, the rain space becomes even more acoustically
uniform. Therefore, the monitoring microbon does not input the residual amount, and the
15-04-2019
2
residual amount is not mistaken as an extraneous sound, and the muffling speaker does not
amplify an unnecessary sound, and the residual amount is less than the howlink cycle. There is
also no howlink caused by entering.
An embodiment of the present invention will be described below with reference to the drawings.
In the description of the embodiment, a headphone type device worn by a person on the head
and used to cancel noise will be described as an example. Further, in the respective drawings, the
same reference numerals indicate the same objects. First, the configuration will be described. FIG.
1 is an overall view showing the configuration of the active noise canceller according to the first
embodiment of the present invention. In the figure, 1 is a muffling speaker, 2 is an auxiliary
speaker, 3 is a monitoring microphone, and 4 is a noise canceling circuit. , 5 is a support
member, 6 is a head phone power bar, 7 is a muffling speaker side how-sink, 8 is a sub-speaker
(rule how-sink. The muffling speaker 1 is for emitting a canceling sound toward the ear cavity E
for erasing the muffling target sound, and is composed of a method sink 1a, a tire frame + b, a
coil + C, and a macnet 1d. The diaphragm surface 1e is a positive pressure surface emitting a
cancellation sound a, and a diaphragm back surface 1f or a negative pressure surface emitting a
negative cancellation sound of opposite phase to the cancellation sound a. Incidentally, on the
first day of the housing, an air vent hole 19 is formed. The sub-speaker 2 is a spino j similar to
the muffling speaker 1, that is, an acoustically equivalent Sbino], and includes a housing 2 a, a
diaphragm 2 b, a coil 2 c, and a magnet 2 d. The method is provided so as to make the faces of
the howsink in a plane-symmetrical manner opposite to each other, that is, the diaphragm back
surface 1f, which is a negative pressure surface, and the diaphragm back surface 2f be opposite
to each other. The dotted line A indicates the plane of symmetry of the two speakers 1.2. The
diaphragm surface 2e of the sub-speaker 2 is a positive pressure surface, and the housing 2a is
formed with a hole 29 for air removal. By the way, the muffling speaker 1 is mounted so as to be
opposed to the user's ear cavity E in the use state, and the space between both the speakers 1.2
and the both speakers 1.2 and the ear cavity E is a headphone Covered by a cover 6, both
speakers 1.2 are fixed to the inside of the headphone cover 6 by a support member 5. Further,
the muffling speaker side how-sink 7 and the sub speaker side how-sink 8 are provided so as to
cover the diaphragm surfaces 1e and 2e of the two speakers 1.2. And both of the how-sinks 7.8
are formed in the symmetrical shape with the same material, and an opening for outputting the
cancellation sound a to the muffling space B on the side of the ear cavity E to the muffling
speaker-side howsink 7 A portion γa is formed, and the auxiliary air side housing 8 is provided
with an opening 8a for inputting an external sound C, and the same area and the same shape on
substantially the front surface of the diaphragms 1b and 2b.
Therefore, the space in the headphone cover 6 is a muffling space B between the ear cavity E and
the muffling speaker side housing Y by the support member 5, the muffling speaker side housing
and the sub speaker side housing 8, and muffling The muffling speaker side space C covered with
15-04-2019
3
the muffling speaker side housing 7 in front of the diaphragm surface 1e of the speaker 1, the
intermediate space between the diaphragms lb and 2b of both the speakers 1 and 2, and the
diaphragm surface 2e of the sub spica 2 It is composed of a sub-speaker side space F covered by
the sub-slip side housing 8 at the front and an extraneous sound side space F between the subspeaker side housings 8 and the back telephone force bar-6. In addition, an opening 6a for
inputting an extraneous sound C is formed in a part on the extraneous sound side space F side of
the head phone power bar 6. Further, the supporting member 5 is provided with a
communication passage 5a communicating the muffling speaker side space C, the intermediate
space and the sub speaker side space E with each other. Then, the monitor microphone 3 is
installed with its tip protruding from the communication path 5a. The noise cancellation circuit 4
generates the cancellation sound a having a substantially reverse phase to the input sound of the
monitor microphone 3 (the extraneous sound C in FIG. 2) based on the input sound of the
monitor microphone 3. The cancellation sound generation signal e is output to the sub speaker 2
in order to generate and emit the sub cancellation sound (a) in the same phase (the same phase
as the input sound of the monitoring microphone 3) with the cancellation sound a at the
diaphragm back surface 2f. And a pre-amplifying preamplifier 4a, a filter circuit 4b for removing
an unnecessary frequency range from the canceling sound, a main power amplifier 4c for main
amplification, and an input sound It is formed to include an inverting circuit 4d which has a
phase of only 180 degrees. Then, to the muffling speaker 1, a cancellation sound generation
signal e in reverse phase to the input signal from the monitoring microphone 3 is given via the
inverting circuit 4d. At this time, in the muffling speaker 1, the negative cancellation sound of a
phase opposite to that of the cancellation sound a is emitted from the diaphragm back surface 1
f. On the other hand, the auxiliary cancellation sound generation signal f in the same phase as the
input signal from the monitoring microphone 3 is given to the front auxiliary speaker 2 without
passing through the inverting circuit, that is, in the auxiliary speaker 2, the diaphragm rear
surface A secondary cancellation sound (a) in the same phase as the cancellation sound a is
emitted from 2f and is emitted to the diaphragm back surface 11 through the secondary
cancellation sound (a) or the hole 29 of the howsink 2a and the hole 19 of the howsink 1a. Is
configured.
At this time, from the diaphragm surface 2e of the auxiliary speaker 2, a negative auxiliary
cancellation sound (b) of the same phase as the negative cancellation sound is emitted. 2 Next,
the operation will be described. The active noise canceller of this embodiment is used in the IJ
ear canal as shown, for example, under external noise such as in the cockpit of an aircraft. In this
case, the external noise (external sound C) passes through the head phone power bar 6, passes
through the external sound side space "and the sub-speaker side space E, and is transmitted into
the communication path 5a and input to the microphone 3 for motor. In the noise cancellation
circuit 4, a cancellation sound generation signal e having a phase opposite to that of the input
signal is formed, and based on this signal e, the cancellation sound a is emitted from the muffling
speaker 1 to the ear cavity E of the user. The external noise (foreign sound C) transmitted to the
15-04-2019
4
ear cavity E is muffled by the cancellation action by the cancellation sound a of the opposite
phase to this. By the way, when the cancellation sound a is emitted from the muffling speaker 1,
the cancellation sound a as shown in FIG. 2 is emitted from the diaphragm surface (positive
pressure surface) 1e of the muffling speaker 1, and (Negative pressure surface) A negative
cancellation noise of opposite phase is emitted from if. On the other hand, in the sub-speaker 2, a
sub-cancelling sound generation signal f in reverse phase to the muffling speaker 1 is given, that
is, a sub-canceling sound (-a) in the same phase as the canceling sound a is emitted from the
diaphragm back surface 2f. On the other hand, from the diaphragm surface 2e, a negative
secondary cancellation noise (-b) having a phase opposite to that of the secondary cancellation
noise is emitted. Therefore, on the plane of symmetry A of the two speakers 1.2, which is a
position where the monitoring microphone 3 is provided, when the negative cancellation sound
from the diaphragm back surface 1f of the muffling speaker 1 is generated, the sub-svica 2 in the
opposite phase is generated. And the cancel sound a from the diaphragm surface 1 e of the
muffling speaker 1 and the diaphragm surface 2 e of the auxiliary speaker 2 in reverse phase
with that of the cancellation sound a from the diaphragm surface 1 e of the muffling speaker 1.
The negative secondary cancellation sound (b) is transmitted equivalently, and the rain sounds
cancel each other and become O. Therefore, in the monitoring microphone 3, only the external
noise C (FIG. 2) is input, and by this, the original signal and the footbank signal of an integral
multiple of 360.degree. It is possible to prevent the occurrence of noise and to prevent the
deterioration of the muffling performance due to the occurrence of howlink. Moreover, since the
monitoring microphone 3 is disposed on the side surface apart from the radiation front of the
cancel sound of the diaphragm 1b, the sound field of the muffling speaker 1 is not disturbed, so
stable muffling performance to high frequency range is obtained. Be
Also, since the monitoring microphone 3 is installed in the input hole 5b near the side surfaces of
both speakers 1.2, only the same external noise as that transmitted to the ear cavity E near the
user's ear cavity E It can be input. Therefore, stable muffling performance can be obtained, and
the effect is obtained that the circuit and microphone for foot bank control are unnecessary and
the configuration is simple. Further, since the same speaker as the muffling speaker 1 is
acoustically equivalent as the sub-speaker 2 for canceling the negative cancellation sound
radiated from the diaphragm back surface 1f 5 of the muffling speaker 1, as the sub-cancellation
generation signal f The input signal from the monitoring microphone 3 can be used as it is, and
there is no need to make the output different for the cancellation sound generation signal e, and
the configuration can be simplified. Furthermore, the sound radiated from both the speakers 1.2
is reflected on the wall surface of the radiation front, but in the present embodiment, the
muffling speaker side space C and the subs V by the subsubino J side housing 8 Since the
speaker side space E is an acoustically equal space, the reflected sound generated on the inner
surface of both the method sinks 7.8 is uniformly generated, both cancel each other, and there is
no residual space, and the noise is eliminated. It is difficult to reinput the reflected sound
generated on the inner surface of the back phone force bar 6 on the side of the space mill and
15-04-2019
5
the extraneous sound side space F into both speaker side spaces C9E by both the method sinks
γ and 8. hard. Therefore, the monitor microphone 3 does not input the residual block, and the
residual block is not mistaken as the extraneous sound C, and the muffling speaker 1 does not
amplify unnecessary sound. The noise reduction performance is improved without the difference
block entering the howlink cycle and the howlink occurring. Next, a second embodiment of the
present invention shown in FIG. 3 will be described. This embodiment is an example in which the
sound absorbing materials 7c and 8c are pasted on the inner surface of both the both sinks 7.8.
Therefore, in the case of the second embodiment, reflected sound is less likely to be generated on
the inner surfaces of the muffling speaker side space C and the sub-speaker side space E by the
sound absorbing material 708c, and the amount of reflected sound is reduced. In this
embodiment, the sound absorbing members 7c and 8c do not prevent the output of the
cancellation sound and the input of the external sound. Although the embodiment has been
described above based on the drawings, the specific configuration is not limited to this
embodiment, and even if there are seven design changes and the like without departing from the
scope of the present invention, they are included in the present invention Be
For example, in the embodiment, the headphone type used by a person to wear on the head and
removed external noise is shown as an example, but the scope of application of the present
invention is not limited to this, for example, a vehicle・ It is installed in the interior of ships,
aircraft, factories, houses etc. (J, it is used to cancel indoor noise etc. and also to cancel
mechanical noise of vehicle air conditioners and other industrial equipment etc. It is also good.
Further, since the present invention cancels the noise to be silenced, the noise to be silenced is
not limited to the noise as described above, and, for example, only arbitrary sounds may be used
for the purpose of harmonizing the noise. There is also a use ability to cancel. (Effects of the
Invention) As described above, in the active noise ganteller of the present invention, since the
microphone for the motor is provided at the position where the cancellation sound and the
secondary cancellation sound cancel each other, as in the prior art, Only the sound to be muted
can be input, or eight or only the sound to be muted can be input, and muffling can be performed
close to the muffling speaker at a position where the monitor microphone is removed from the
front of the cancellation sound The effect that the performance can be improved can be obtained.
In addition, in the present invention, since the how-sink that symmetrically forms the muffling
speaker side space and the sub-speaker side space is provided, the residual person is not
generated due to the phase shift of the reflected sound, and the residual person is mistaken as
foreign sound. At the same time it is not possible to amplify an unnecessary sound as a
cancellation sound due to the noise, there is also no waylink caused by this residual person, and
an effect that the muffling effect can be improved can be obtained.
[0002]
Brief description of the drawings
15-04-2019
6
[0003]
FIG. 1 is an overall view showing the configuration of the active noise canceller according to the
first embodiment of the present invention, and FIG. 2 is a negative pressure person with positive
pressure teeth parallel to the muffling speaker by the active noise canceler according to the first
embodiment. FIG. 3 is a cross-sectional view of the main part of an active noise canceller
according to a second embodiment of the present invention.
C: Muffling speaker side space E: Sub-speaker side space a: cancellation sound C: foreign sound 1:
muffling speaker 1e: diaphragm surface (positive pressure surface) 1f: diaphragm back surface
(Negative pressure surface) 2 · · · Sub-speaker 2e ... diaphragm surface (positive pressure surface)
2f ... diaphragm back surface (negative pressure surface) 3 ... monitoring microphone 4 ... noise
cancellation circuit 7 · · · housing 8 ... Howsink
15-04-2019
7
Документ
Категория
Без категории
Просмотров
2
Размер файла
18 Кб
Теги
description, jph03195295
1/--страниц
Пожаловаться на содержимое документа