close

Вход

Забыли?

вход по аккаунту

JPS5911098

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 JPS5911098
[0001]
The present invention relates to a sound reproducing apparatus that stably and effectively
reduces distortion of an entire sound reproducing system including a speaker. 2. Description of
the Related Art Conventionally, as a sound reproduction apparatus for improving distortion of
the entire sound reproduction system including a speaker, for example, the one shown in FIG. 1
is known. The sound reproduction apparatus shown in this figure is a so-called MFB, and when
the input signal e1 is amplified by the amplifier 1 to drive the speaker 2, the speed component of
the output of the speaker 2 is detected by the voice coil 3 for detection. , And this feedback signal
is negatively fed back to the input side of the multiplier 18i via the feedback control circuit 4.
However, in the sound reproducing apparatus as shown in FIG. 1, since all the signal components
including the distortion component are negatively fed back, if the dog # is subjected to negative
feedback, the amplification operation is not performed due to the phase delay and the like. There
is a problem that it becomes stable (that is, it is easy to cause an oscillation phenomenon etc.).
Therefore, this type of sound reproducing apparatus is extremely difficult in practice to increase
the feedback value to reduce distortion, and is therefore adopted for the limited purpose of
controlling the low frequency characteristics. It is the present condition. SUMMARY OF THE
INVENTION In view of the above situation VC, the present invention provides an audio
reproduction apparatus capable of stably and effectively reducing distortion of the entire audio
reproduction system including a speaker, and detects a signal component corresponding to an
output of the speaker Detection means, and a filter circuit for giving a signal equivalent to the
detection characteristic of the detection means to the signal of the input end of the amplifier for
driving the speaker and outputting the signal, and the detection means using the first arithmetic
circuit Calculating the difference between the output of the filter circuit and the output of the
filter circuit of Ail, adding the output of the seventh arithmetic circuit to the input signal by the
first arithmetic circuit and supplying the result to the input end of the amplifier The Hereinafter,
13-05-2019
1
an embodiment of a sound reproducing apparatus according to the present invention will be
described in detail with reference to the drawings. The first diagram is a circuit diagram showing
the configuration of an embodiment of the sound reproducing apparatus according to the
present invention. In this figure, reference numeral 5 denotes an adder (first operation circuit),
and this adder 5 adds an input signal ei to the signal input terminal 6 and a differential amplifier
7 (described later). The outputs of the first arithmetic circuit) are added to the amplifier 1 and
the filter circuit 8 respectively. The output of the amplifier 1 is connected to one end of the voice
coil 9 of the speaker 2, and the other end of the voice coil 9 is grounded. Next, the speaker 2 will
be described in detail with reference to FIG. 3. On the outer peripheral surface of the bobbin 11
fixed to the cone 10, a cylindrical metal ring other than the voice coil 9 is formed. The RL piece
12a (detection means) is provided, and the pole piece 14 (if!
On the surface of I, an electrode 12b (detection means) made of a cylindrical metal is provided on
the outside of the electrode 12a and coaxial with the electrode 12a. In this case, the gap between
the outer peripheral surface of the electrode 12a and the inner peripheral surface of the
electrode 12b is extremely small, and when the bobbin 11 vibrates in the vertical direction in the
figure, 1L? The area of the facing surfaces of the pole 12a and the electrode 12b is changed, so
that the displacement of the cone 10 can be detected as a change in electric capacity. In addition,
with speaker 2F! In the following, 15 is an annular magnet, 16 is an annular tots yoke, and 17 is
a damper. Referring back to FIG. 2, the electrode 12b is biased by the DC power supply 18 to a
positive potential with respect to the ground potential. Further, the electrode 12 a is connected to
the non-inversion input terminal of the operational amplifier 20 constituting the voltage follower
19 and is grounded via the resistor 21 having a high resistance value. The output of the
operational amplifier 20 is supplied to the inverting input terminal of the differential amplifier 7.
On the other hand, the filter circuit 8 has a transfer characteristic equivalent to the amplitude
(displacement) -frequency characteristic of the speaker 2, and its output is supplied to the noninverting input terminal of the differential amplifier 7) and this difference The Nor amplifier 7
pulls the output of the voltage meter lower 19 from the output of the filter circuit 8 and supplies
a signal corresponding to the result of the pull to the adder 5. Next, the operation of this
embodiment in the above configuration will be described. First, the amplitude-frequency
characteristics of the speaker 2 are vc as shown in Fig. Μ from the well-known characteristics of
the speaker, and with the lowest resonance frequency fO as a bending point, the amplitude is
attenuated by approximately l co d B10 CT It has the following characteristics. On the other
hand, since the electrode 12b shown in FIG. 2 is biased to a positive potential and the electrode
128L is grounded via the resistor 21, these both electrodes 12a. Between the 12b and 12b, a
charge can not be accumulated and this charge hardly leaks out or is released due to the high
resistance of the resistor 21. Therefore, if the cone 10 of the speaker 2 is displaced and the
capacitance between the electrodes 12a and 12b changes, a north voltage will appear on the
electrode 12a in proportion to the displacement ja '(i.e., the amplitude) of the cone 10 Therefore,
the amplitude of the speaker 2 having the amplitude-frequency characteristic as shown in FIG. 6
13-05-2019
2
can be taken out as a pressure signal from the output end of the voltage follower.
That is, the signal supplied to the inverting input terminal of the differential amplifier 7 conforms
to the input / output characteristic of the speaker 2. On the other hand, the signal supplied to the
input end of the amplifier 1 (i.e., the signal serving as a source when driving the speaker 2) has a
characteristic equivalent to that shown in FIG. It is supplied to the noninverting input terminal of
the differential amplifier 7. Therefore, as an output signal of the differential amplifier 7, a signal
corresponding to the subtraction result when the output of the voltage filter 19 is subtracted
from the output of the filter circuit 8, that is, after being input to the amplifier 1, the speaker 2
power 4 etc. A signal corresponding to the distortion generated until the output is obtained.
Then, the output signal of this differential amplifier 7 is added to the manual signal j, ei in 7 Jil
'JA in the device 5 in the direction to cancel the pre-G self distortion / J1. される。 However,
according to this embodiment, by setting the gains of the differential amplifier 7 and the filter
circuit 8 to appropriate values, the connection 1911 to + i ′ IH1, the contact Me f ′ between
the amplifier 1 and the speaker 2 can be obtained. It is possible to completely cancel the
distortion that occurs in tli and 7 itself 2. Then, in this case, it is fed back to the adder 31-The
sign is a distortion-only small signal corresponding to the distortion only, and it is possible to
apply a very effective and extremely female feedback, even if the position a Even if there is a
delay, the amplification operation will not be stable. According to this embodiment, since the E
component of the output of the speaker 2 is extracted as an amplitude having a linear
characteristic as shown in FIG. V, the filter circuit 8 has an extremely simple circuit configuration.
It is very convenient in practice. In this embodiment, although the amplitude of the speaker 2 is
detected by using the change in each lid between the electrodes 12a and 12b, the change in the
vibration IIV, X can be detected by using the light-resistance element or the like for the eleventh.
May be detected. In this embodiment, although the signal component corresponding to the
output of the speaker 2 is detected as the amplitude, the signal component corresponding to the
output of the speaker 2 is detected as the velocity using the voice coil 8 for detection described
in Ail. May be However, in this case, as shown in FIG. 5, the speed-frequency% characteristic of
the speaker is such that it is attenuated by 6 dB10 CT as the frequency rises or falls with the
lowest resonance frequency fo at the top. The circuit configuration is complicated. As is apparent
from the above description, according to the sound vp + device according to the present
invention, the detection means for detecting the signal component corresponding to the output
of the speaker, and the signal at the input end of the amplifier are equivalent to the detection
characteristics of this detection means And the seventh arithmetic circuit determines the
difference between the output of the detection means and the output of the filter circuit, and the
second arithmetic circuit determines the seventh deduction on the input signal. Since the outputs
of the circuits are added and supplied to the input end of the amplifier, distortion components of
the entire sound reproduction system including the amplifier, the connection between the
amplifier 111i and iR- and the speaker, and the speaker are extracted The distortion can be
canceled with extremely high precision, effectively and stably by feeding back only the minute
13-05-2019
3
signal corresponding to this distortion component.
[0002]
Brief description of the drawings
[0003]
FIG. 1 is a circuit diagram showing a configuration example of a conventional sound reproducing
apparatus, FIG. 2 is a circuit diagram showing a configuration of an embodiment of the present
invention, and FIG. 3 is an iP narrow configuration of the speaker 2 in the embodiment. FIG. V is
an amplitude-frequency characteristic diagram of the speaker, and FIG. 5 is a velocity-frequency
characteristic diagram of the speaker.
1 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · amplifier · 2 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Seventh arithmetic circuit (differential amplifier), 8: filter
circuit, 12a, 12b: detection means (electrodes).
13-05-2019
4
1/--страниц
Пожаловаться на содержимое документа