close

Вход

Забыли?

вход по аккаунту

?

JP2009017403

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 JP2009017403
The present invention provides a speaker capable of simplifying the assembly process and
accurately detecting the vibration of a vibrating member. A speaker (20) transmits a cone wave
(2) generating a sound by vibration, a drive unit for vibrating the cone paper (2), and a pulse
wave to the cone paper 2 at predetermined time intervals. The sound wave transmitter 6a and a
sound wave receiver 6b for detecting a reflected wave of the pulse wave transmitted by the
sound wave transmitter 6a by the cone paper 2. The drive unit is a sound wave receiver after the
pulse wave is transmitted. The vibration of the cone paper 2 is detected based on the change in
the arrival time to reach 6 b, and the vibration of the cone paper 2 is subjected to negative
feedback control based on the detected vibration. [Selected figure] Figure 3
スピーカ
[0001]
The present invention relates to a loudspeaker, and more particularly to a loudspeaker provided
with a vibrating member that generates a sound by vibrating and a drive unit for vibrating the
vibrating member.
[0002]
BACKGROUND Conventionally, there is known a speaker provided with a vibrating member that
generates a sound by vibrating and a drive unit for vibrating the vibrating member.
08-05-2019
1
Such a speaker has a disadvantage that it is difficult to accurately vibrate the vibrating member
at the predetermined frequency when the vibrating member is driven such that the drive unit
vibrates at the predetermined frequency. Therefore, conventionally, in order to eliminate the
above-mentioned disadvantages, negative feedback control is performed so as to detect the
actual vibration of the vibrating member and correct the drive of the vibrating member by the
drive unit based on the vibration to drive the vibrating member. A so-called MFB (Motional
Feedback) type speaker configured to perform has been proposed (see, for example, Patent
Documents 1 to 3). Also, conventionally, there is known a microphone provided with a
mechanism for detecting the frequency of the vibrating member (see, for example, Patent
Document 4).
[0003]
Patent Document 1 discloses a structure in which the vibration of the vibrating member is
detected by the reflecting plate attached to the vibrating member and the detector including the
light emitting element and the light receiving element provided at the position facing the
reflecting plate. There is. In Patent Document 1, light emitted from a light emitting element is
reflected by a reflection plate attached to a vibrating vibration member to be received by a light
receiving element. Since the intensity of the detection signal by the light receiving element
fluctuates in accordance with the vibration displacement of the vibrating member, the
displacement of the vibrating member is detected. Moreover, in the said patent document 1, the
structure which detects the vibration speed of a vibration member by the Doppler effect is also
disclosed. That is, when the reflected light from the reflection plate attached to the vibrating
member is received, the wavelength of the reflected light fluctuates in proportion to the vibrating
velocity of the vibrating member, so that the vibrating velocity of the vibrating member is
detected. In Patent Document 1 described above, the vibration of the vibrating member is
subjected to negative feedback control based on the signal of the vibration displacement or the
vibration speed of the vibrating member.
[0004]
In Patent Document 2, as in Patent Document 1, the light emitted from the light emitting element
is reflected by the reflection plate attached to the vibrating member that vibrates, and is received
by the light receiving element. Further, Patent Document 2 discloses a configuration in which a
light emitting element is attached to a vibrating member and a light receiving element is
provided at a position opposite to each other to detect a displacement of the vibrating member.
In Patent Document 2 described above, the vibration of the vibrating member is subjected to
08-05-2019
2
negative feedback control based on the signal of the vibration displacement of the vibrating
member.
[0005]
Moreover, while the said patent document 3 detects the sound emitted from the vibration
member by the microphone, the structure which carries out negative feedback control of the
vibration of a vibration member based on the detection signal is disclosed.
[0006]
Moreover, in the said patent document 4, while irradiating light to the vibration member which
has a light reflection function, the structure which detects a vibration of a vibration member is
disclosed by light-receiving the reflected light.
[0007]
Patent No. 2940587 JP, 2007-88608, A JP, 11-355893, A JP, 3132, 270
[0008]
However, in Patent Document 1 described above, since the vibration displacement of the
vibrating member is detected based on the intensity change of the reflected light, the light
receiving element receives light when the position adjustment of the light emitting element, the
light receiving element and the reflection plate is shifted It is considered difficult to accurately
detect the change in intensity of the reflected light.
For this reason, there is a problem that the assembling process becomes complicated because the
accuracy of position adjustment of the optical system is required at the assembling stage.
Further, in the configuration utilizing the Doppler effect, when the frequency of the vibrating
member is low and the vibration velocity of the vibrating member is low, the change in
wavelength due to the Doppler effect is also small, so detection of low frequency vibration
becomes difficult.
Therefore, there is a problem that it is difficult to detect the vibration of the vibrating member
08-05-2019
3
accurately.
[0009]
Further, in Patent Documents 2 and 3 as well as Patent Document 1, there is a problem that the
assembling process becomes complicated since the accuracy of position adjustment of the optical
system is required at the assembling stage as in the Patent Document 1.
[0010]
Further, in Patent Document 4 described above, it is considered that there is a possibility that
sounds etc. emitted from other speakers may be detected at the same time because the
configuration is such that the sound actually emitted from the vibrating member by the
microphone is detected.
For this reason, there is a problem that it is difficult to accurately detect the vibration of the
vibrating member.
[0011]
The present invention has been made to solve the problems as described above, and one object of
the present invention is to provide a speaker capable of simplifying the assembly process and
accurately detecting the vibration of the vibrating member. To provide.
Means for Solving the Problems and Effects of the Invention
[0012]
The speaker according to one aspect of the present invention is a vibration member that
generates sound by vibrating, a drive unit for vibrating the vibration member, and a transmission
that transmits pulse waves to the vibration member at predetermined time intervals. Unit, and a
detection unit for detecting a reflection wave of the pulse wave transmitted by the transmission
unit by the oscillating member, and the drive unit changes a arrival time from the transmission of
the pulse wave to the arrival of the reflection wave at the detection unit While detecting the
vibration of a vibrating member based on, it is comprised so that feedback control of the
vibration of a vibrating member may be carried out based on the detected vibration.
08-05-2019
4
[0013]
In the speaker according to the one aspect, as described above, the vibration of the vibrating
member is accurately detected by detecting the vibration of the vibrating member based on the
change in the arrival time from the transmission of the pulse wave to the arrival of the reflected
wave to the detection unit. Vibration of the vibrating member can be detected.
That is, the distance between the vibrating member and the transmitting unit and the detecting
unit (moving distance of the pulse wave) fluctuates with the vibration of the vibrating member.
Since the velocity of the pulse wave is considered to be substantially constant, the change in the
moving distance of the pulse wave is proportional to the change in the arrival time of the pulse
wave. In addition, since the change in the movement distance of the pulse wave is a change in
position of the portion of the vibrating member irradiated with the pulse wave, the pulse wave of
the vibrating member is irradiated by detecting the change in arrival time of the pulse wave. The
position change of the part can be detected. Thereby, the vibration of the vibrating member can
be detected. As described above, when the vibration of the vibrating member is detected by the
change in the arrival time of the pulse wave, the sound of the other speaker and the like are not
affected, so that the vibration of the vibrating member can be accurately detected. Further, when
detecting the vibration of the vibrating member based on the change in the arrival time of the
pulse wave, since the positional change of the portion of the vibrating member irradiated with
the pulse wave is detected, unlike the case of detection by the Doppler effect, Even when the
vibration velocity of the vibration member is low (when the frequency is low), the vibration can
be detected accurately. In addition, when detecting the vibration of the vibrating member based
on the change in arrival time of the pulse wave, the detection unit only needs to detect whether
or not the pulse wave is detected, and it is necessary to detect the time change such as light
intensity Absent. For this reason, since it is not necessary to have the accuracy of the positional
adjustment of the transmitting unit and the detecting unit at the assembly stage, the assembly
can be easily performed. This can simplify the assembly process.
[0014]
In the speaker according to the aforementioned aspect, preferably, the time interval at which the
pulse wave is transmitted is smaller than the vibration period when the vibrating member
vibrates. According to this structure, it is possible to detect a time change of the position of the
08-05-2019
5
vibrating member within one cycle of the vibration of the vibrating member, so that the vibration
of the vibrating member can be detected.
[0015]
Preferably, in the speaker according to the above aspect, the pulse wave includes a pulse sound
wave. According to this structure, unlike the light (electromagnetic wave), the sound wave travels
in a weak manner, unlike the light (electromagnetic wave). Therefore, in the position adjustment
of the transmitting unit and the detection unit during assembly, compared to the case where
vibration is detected by pulse waves of light (electromagnetic wave). You don't need more
precision. Thus, the assembly process can be simplified.
[0016]
In this case, preferably, the frequency band of the pulse sound wave is different from the
frequency band at which the vibrating member vibrates. According to this structure, it is possible
to suppress the occurrence of an error in the detection result due to the detection unit detecting
the sound wave by the vibrating member.
[0017]
In the configuration in which the pulse wave includes a pulse sound wave, preferably, the
transmitting unit and the detecting unit are attached to a member other than the vibrating
member and the driving unit. According to this structure, the feedback control can be performed
without attaching the component for performing the negative feedback control to the vibrating
member and the drive unit. Therefore, the component for performing the feedback control may
be the vibrating member or the drive unit. It is possible to suppress that the vibration of the
vibrating member is affected by the attachment.
[0018]
Hereinafter, an embodiment of the present invention will be described based on the drawings.
[0019]
08-05-2019
6
FIG. 1 is a perspective view showing the overall configuration of a loudspeaker according to an
embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the speaker shown in FIG. FIG. 3 is a block diagram
showing a drive circuit of the speaker shown in FIG. First, the structure of a speaker 20
according to an embodiment of the present invention will be described with reference to FIGS. 1
to 3.
[0020]
As shown in FIGS. 1 and 2, the speaker 20 according to the present embodiment includes a metal
frame 1, a cone paper 2 that generates sound when vibrated, a damper 3, a cylindrical yoke 4,
and a ring. And a magnet 5 disposed on the outer surface side of the yoke 4. In addition, the
speaker 20 according to the present embodiment is configured to be subjected to negative
feedback control (negative feedback control) by an MFB (Motional FeedBack) method. The MFB is
a method of detecting the vibration of the cone paper 2 and performing negative feedback
control of the vibration of the cone paper 2 based on the frequency of the detected vibration.
Further, the speaker 20 according to the present embodiment includes the sensor 6 for detecting
the vibration of the cone paper 2 by the MFB method and the sensor support member 7 for
supporting the sensor 6. The cone paper 2 is an example of the “vibration member” in the
present invention.
[0021]
Further, as shown in FIG. 2, the speaker 20 has a cylindrical coil bobbin 8 joined to the root
portion of the cone paper 2, and a joint portion between the cone paper 2 and the coil bobbin 8
is an inner side of the coil bobbin 8. A cap 9 is provided to close the hollow portion of Further, in
the cone paper 2 to which the coil bobbin 8 and the cap 9 are joined, one end of the cone paper
2 (end on the side not joined to the coil bobbin 8) is uniformly adhered to the cone edge 10; The
cone edge 10 is held to the frame 1 by being glued to the frame 1. Further, the voice coil 11 is
fixedly wound around the coil bobbin 8, and the voice coil 11 wound around the coil bobbin 8 is
disposed at a position surrounded by the magnet 5. The speaker 20 configured in this manner
generates a sound wave as follows. That is, by flowing a current through the voice coil 11, a force
generated by the current flowing through the voice coil 11 and the magnetic field generated in
08-05-2019
7
the magnet 5 is generated via the voice coil 11 and the coil bobbin 8 based on Fleming's left law.
It is transmitted to 2. Then, the air is vibrated by the cone paper 2 vibrating by the transmitted
force, whereby a sound wave is generated.
[0022]
The damper 3 is formed in a circular shape as shown in FIGS. 1 and 2 and is joined along the
inner side surface of the frame 1. In the damper 3, the coil bobbin 8 is disposed so as to
penetrate through the central portion, and the coil bobbin 8 is supported by being joined to the
coil bobbin 8 at the penetrating portion. Further, the damper 3 supports the coil bobbin 8 and is
configured to be expandable and contractible so that the cone paper 2 and the coil bobbin 8
vibrate normally.
[0023]
Also, the sensor support member 7 is attached to the top surface of the frame 1. The sensor
support member 7 protrudes upward from the frame 1 and is bent so that the tip 7 a extends
inside the cone paper 2. Further, the tip 7 a is disposed in the vicinity of the cap 9 of the cone
paper 2.
[0024]
In addition, the sensor 6 is attached to the tip 7 a of the sensor support member 7. The sensor 6
is composed of a pair of sound wave transmitters 6 a and a sound wave receiver 6 b. The sound
wave transmitter 6a is configured to transmit pulse sound waves at predetermined time intervals.
The sound wave receiver 6b can also receive the reflected wave of the pulse sound wave
transmitted from the sound wave transmitter 6a by the cone paper 2. Further, the sensor 6
attached to the tip 7 a of the sensor support member 7 is disposed to face the side surface of the
cone paper 2 near the cap 9. The side surface of the cone paper 2 in the vicinity of the cap 9 is
located on the voice coil 8 side in the cone paper 2, so that the vibration most similar to the
vibration of the voice coil 8 is performed. Also, the pulse sound wave transmitted from the sound
wave transmitter 6a is incident substantially perpendicularly on the surface of the cone paper 2
and is reflected substantially perpendicularly from the surface of the cone paper 2 and received
by the sound wave receiver 6b. Be done. Further, the time interval at which the pulse sound wave
is transmitted is smaller than the vibration period when the cone paper 2 vibrates. Further, the
08-05-2019
8
frequency band of the sound wave transmitted from the sound wave transmitter 6a is different
from the frequency band when the cone paper 2 vibrates.
[0025]
Further, as shown in FIG. 3, the loudspeaker 20 according to the present embodiment includes an
analog negative feedback control circuit. The negative feedback control circuit is configured to
detect the vibration of the cone paper 2 and to perform negative feedback control of the
vibration of the cone paper 2 based on the vibration of the cone paper 2. Specifically, the
transmission amplifier 12 amplifies the signal input from the transmission circuit and inputs the
amplified signal to the sound wave transmitter 6a. Thereby, the sound wave transmitter 6a
transmits a pulse sound wave at a predetermined time interval. Further, the reception amplifier
13 amplifies the pulse signal received by the sound wave receiver 6 b and inputs it to the
demodulation circuit 14. The demodulation circuit 14 obtains the vibration of the cone paper 2
based on the input pulse signal. Further, in the differential amplifier 15, an audio signal from an
audio output device (not shown) or the like and an output signal from the demodulation circuit
14 are input. In this differential amplifier 15, the audio signal from the audio output device or
the like is corrected based on the output signal from the demodulation circuit 14. The output
signal of the differential amplifier 15 is amplified by the power amplifier 16 and output. The
output signal from the power amplifier 16 drives the coil bobbin 8 and the voice coil 11 (see FIG.
2) to vibrate the cone paper 2.
[0026]
4 to 6 are conceptual diagrams showing a state in which sound wave pulses are applied to
vibrating cone paper. FIG. 7 is a diagram showing the transmission time of the sound wave pulse
and the detection time of the sound wave pulse when the sound wave pulse is transmitted every
time τ. Next, with reference to FIG. 4 to FIG. 7, the detection principle of the vibration of the
cone paper 2 of the speaker 20 according to the present embodiment will be described.
[0027]
As shown in FIG. 4, when the cone paper 2 is not vibrating and when the position of the cone
paper 2 is located at the center of vibration, a pulse sound wave is emitted from the sound wave
transmitter 6 a and reflected on the cone paper 2. And the moving distance until it is received by
08-05-2019
9
the sound wave receiver 6b is L. Further, as shown in FIG. 5, when the cone paper 2 is located at
a position away from the sensor 6, the moving distance of the pulse sound wave is L + δL.
Further, as shown in FIG. 6, when the cone paper 2 is located at a position close to the sensor 6,
the moving distance of the pulse sound wave is L−δL. Therefore, the change in the movement
distance of the pulse sound wave is proportional to the change in the position of the portion of
the cone sheet 2 to which the pulse sound wave is irradiated. Further, since the velocity of the
pulse sound wave is substantially constant, it is possible to detect a change in the moving
distance of the pulse sound wave as a change in time from the transmission of the pulse sound
wave to the reception thereof. That is, it is possible to obtain a change in position of the portion
of the cone paper 2 to be irradiated with the pulse sound (vibration of the cone paper 2) by
detecting a change in time from transmission of the pulse sound wave to reception thereof. It is.
[0028]
Assuming that the time from transmission of a pulse sound wave to reception in the state shown
in FIG. 4 is a reference arrival time, as shown in FIG. 7, the time t1 after the reference arrival time
has elapsed since the first pulse was transmitted. The time difference d1 from the time T1 at
which the first pulse is received by the sound wave receiver 6b is "0". That is, when the first pulse
is reflected by the cone paper 2, the cone paper 2 is located at the vibration center shown in FIG.
The time difference d2 between the time t2 after the reference arrival time has elapsed since the
transmission of the second pulse and the time T2 at which the second pulse is received by the
sound wave receiver 6b is a positive value. That is, when the second pulse is reflected by the
cone paper 2, it indicates that the cone paper 2 is positioned at a distance from the sensor 6 as
shown in FIG. 5. The time difference d3 between the time t3 after the reference arrival time has
elapsed since the transmission of the third pulse and the time T3 at which the third pulse was
received by the sound wave receiver 6b is larger than the time difference d2 of the second pulse.
Therefore, when the third pulse is reflected by the cone paper 2, the cone paper 2 is located at a
position further away from the sensor 6 than when the third pulse is reflected by the cone paper
2. The time difference d9 between the time t9 after the reference arrival time has elapsed since
the transmission of the ninth pulse and the time T9 at which the ninth pulse was received by the
sound wave receiver 6b is a negative value. Therefore, when the ninth pulse is reflected by the
cone paper 2, the cone paper 2 indicates that it is located at a distance from the sensor 6, as
shown in FIG. In the present embodiment, the vibration of the corn paper 2 is detected by such a
principle.
[0029]
08-05-2019
10
In the present embodiment, as described above, the vibration of the cone paper 2 is accurately
detected by detecting the vibration of the cone paper 2 based on the change in the arrival time
from the transmission of the pulse sound wave to the arrival of the reflection wave to the sound
wave receiver 6b. The vibration of the cone paper 2 can be detected. As described above, when
the vibration of the cone paper 2 is detected by the change in the arrival time of the pulse sound
wave, the sound of the other speakers and the like are not affected, so the vibration of the cone
paper 2 can be accurately detected. . In addition, when detecting the vibration of the cone paper
2 by the change of the arrival time of the pulse sound wave, the position change of the portion of
the cone paper 2 irradiated with the pulse sound wave is detected. Differently, even when the
vibration speed of the cone paper 2 is small (when the frequency is small), the vibration can be
accurately detected. In addition, when the vibration of the cone paper 2 is detected by the change
in arrival time of the pulse sound wave, the sound wave receiver 6b only needs to detect whether
or not the pulse sound wave is detected, and detects the time change such as light intensity.
There is no need to For this reason, since accuracy is not required in the position adjustment of
the sound wave transmitter 6a and the sound wave receiver 6b in the assembly stage, the
assembly process can be simplified.
[0030]
Further, in the present embodiment, as described above, since the sound wave is weak in
straightness unlike the light (electromagnetic wave) by using the pulse sound wave, compared
with the case where the vibration is detected by the pulse wave of light (electromagnetic wave).
There is no need for more precision in the positioning of the sound wave transmitter 6a and the
sound wave receiver 6b in the assembly stage. Thus, the assembly process can be simplified.
Further, as in the case of detecting a vibration by a pulse wave of light (electromagnetic wave),
there is no need to perform processing for reflecting light such as attaching a reflection plate to
the cone paper 2 or depositing a metal film.
[0031]
Further, in the present embodiment, as described above, the sound wave by the cone paper 2 is
detected in the sound wave receiver 6 b by using the pulse sound wave of the frequency different
from the frequency band when the cone paper 2 vibrates. It is possible to suppress the
occurrence of an error in the detection result due to the above.
[0032]
Further, in the present embodiment, as described above, by attaching the sound wave transmitter
6 a and the sound wave receiver 6 b to the sensor support member 7 attached to the frame 1, the
08-05-2019
11
sensor 6 for performing negative feedback control vibrates. The negative feedback control can be
performed without attaching to the cone paper 2, the cap 9, the coil bobbin 8, the voice coil 11,
etc., so that the sensor 6 for performing negative feedback control is the cone paper 2, the cap 9,
the coil bobbin 8 and the voice It is possible to suppress that the vibration of the cone paper 2,
the cap 9, the coil bobbin 8 and the voice coil 11 is affected due to the attachment to the coil 11.
[0033]
It should be understood that the embodiments disclosed herein are illustrative and nonrestrictive in every respect.
The scope of the present invention is indicated not by the description of the embodiments
described above but by the claims, and further includes all modifications within the meaning and
scope equivalent to the claims.
[0034]
For example, in the above embodiment, the cone paper 2 is irradiated with the pulse sound wave,
but the present invention is not limited to this, and the cap 9 may be irradiated.
[0035]
Moreover, although the example which detected the vibration of cone paper 2 using the pulse
sound wave was shown in the said embodiment, this invention may use not only this but the
pulse of light (electromagnetic wave).
[0036]
Further, in the present embodiment, an example using the analog negative feedback control
circuit shown in FIG. 3 is shown, but the present invention is not limited to this, and like the
speaker 30 according to the modification shown in FIG. The negative feedback control circuit of
the equation may be used.
In this digital negative feedback control circuit, the pulse signal output from the reception
amplifier 13 is input to the control unit 17 formed of an IC or the like.
08-05-2019
12
In the control unit 17, processing similar to that of the demodulation circuit 14 and the
differential amplifier 15 of FIG. 3 is performed by digital processing.
In the present invention, since the digital signal indicating presence / absence of detection of a
pulse is handled, the effect of noise can be reduced by performing digital processing in this
manner, as compared to the case of performing analog processing.
[0037]
Moreover, although the example which irradiated the pulse sound wave from the outer side of
the cone paper 2 was shown in the said embodiment, this invention may irradiate a pulse sound
wave from the inside of the cone paper 2 not only this.
[0038]
It is a perspective view showing the whole composition of the speaker by one embodiment of the
present invention.
It is sectional drawing which shows the speaker shown in FIG. It is a block diagram which shows
the negative feedback control circuit of the speaker shown in FIG. It is a schematic diagram
which shows the case where cone paper is not vibrating, or when located in the vibration center.
It is a schematic diagram which shows the case where cone paper is located in the position
estranged with respect to a sensor. It is a schematic diagram which shows the case where cone
paper is located in the position estranged with respect to a sensor. It is a figure which shows the
transmission time of an acoustic pulse, and the detection time of an acoustic pulse. It is a block
diagram which shows the negative feedback control circuit of the speaker by the modification of
this invention.
Explanation of sign
[0039]
2 cone paper (vibration member) 6a sound wave transmitter (transmission unit) 6b sound wave
receiver (detection unit) 9 cap (vibration member) 20 speaker
08-05-2019
13
08-05-2019
14
Документ
Категория
Без категории
Просмотров
0
Размер файла
24 Кб
Теги
jp2009017403
1/--страниц
Пожаловаться на содержимое документа