close

Вход

Забыли?

вход по аккаунту

JPS63260395

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 JPS63260395
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to
microphones used in audio equipment, and more specifically, to convert sound waves such as
music directly into digital electrical signals. It relates to the crophone. (Prior Art) A conventional
system for inputting a sound wave such as music as a digital electric signal to a digital audio
device will be described with reference to FIG. FIG. 3 is a block diagram of a signal processing
circuit for converting an analog electrical signal of a microphone into a digital electrical signal. In
the figure, the sound wave S is converted into a minute analog electrical signal by the
microphone 1 to which it is inputted, amplified to a level that can be transmitted by the
microphone amplifier 2, and passes through the transmission path 3 and indicated by a dashed
frame in the figure. Are input to the digital audio device 4. The analog electrical signal input to
the digital audio device 4 is amplified to a level capable of being sampled by the amplifier 5 and
then unnecessary harmonic components are reduced by the low pass filter 6 in order to prevent
occurrence of aliasing distortion due to alias effect at the time of sampling. Is removed. The
analog electrical signal from which the unnecessary harmonic components have been removed is
sampled and held by the sample-and-hold amplifier 8 by the sample-and-hold control signal C
output from the clock generator 7. The conversion start signal is output as the digital electric
signal E by the analog-to-digital converter 9. (Problems to be solved by the invention) However,
in the above configuration, there is a problem that it is difficult to obtain the analog-to-digital
converter 9 which is expensive and has stable performance. さらに。 Since the output of the
microphone passes through the transmission path 3 in the form of an analog signal, noise is
likely to be mixed in, and there is also a problem that distortion is likely to occur because the
amplification is turned green. The present invention solves the above problems, and provides a
microphone that can convert sound waves such as music into digital electrical signals and
directly supply them to digital audio equipment without the need for complicated signal
05-05-2019
1
processing circuits. It is a thing. (Means for Solving the Problems) In order to solve the above
problems, the present invention comprises a light source having an irradiation angle, a central
portion for absorbing or transmitting light, and a portion for reflecting light to the periphery
thereof. A light receiving element which is formed on a plane orthogonal to the optical axis of the
light source and is interlocked with the light source, and a plurality of light receiving elements
for receiving the reflected light from the diaphragm and converting it into an electric signal. The
microphone consists of the unit, and the displacement of the diaphragm vibrated by the sound
wave in the front-rear direction is replaced with the change of the distance from the diaphragm
to the light receiver, and detected as the change of the reflected light reception area of the light
receiver. The vibration of the diaphragm due to is output as a digital electrical signal.
(Operation) According to the above configuration, since the light source at the irradiation angle
2α and the diaphragm are linked, even if the diaphragm is displaced by ± ΔX by the sound
wave, the distance from the light source to the diaphragm is changed. No, the diameter of the
illuminated circle on the diaphragm does not change, but if the distance between the changing
diaphragm and the fixed light receiving part changes by the displacement amount ± ΔX of the
diaphragm, the maximum incident angle of light to the diaphragm Since the reflection angles are
both equal to each other, the reflected light receiving circle diameter of the light receiving part
changes by ± 2Δx tan α. That is, if the diaphragm moves away from the light receiving portion
by ΔX, the diameter of the 1 reflected light receiving circle increases by 2Δx tan α, and
conversely, if it approaches ΔX, the diameter decreases by 2 Δx tan α. A change in the area of
the reflected light receiving circle can be detected by a plurality of light receiving elements, and
the number of the received elements can be counted to convert it into a digital electric signal. An
embodiment according to the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 (a), (b) and (Q) are respectively side cross-sectional views of a microphone according to the
present invention. They are a back sectional view and a front sectional view which were cut in
the AA 'plane and the BB' plane respectively and were seen from the direction of the arrow. In
FIG. 1 (a), the microphone according to the present invention is provided in the form of two
cylinders in the interior of the case 10 so as to be orthogonal to the center line, and as shown in
FIG. 1 (b) Alternatively, the diaphragm 11 includes a circular portion 11a that transmits light and
a portion 11b that reflects light surrounding the same, and the above-mentioned center line
coincides with the optical axis and has an irradiation angle 2α in conjunction with the
diaphragm 11 It comprises a light source 12 and a light receiving portion 13 disposed behind
the light source 12 and formed of a plurality of light receiving elements such as COD. The
absorbing or transmitting portion 11 a formed at the center of the diaphragm 11 is set so that
the reflected light does not return to the light source 12. The operation of the thus configured
microphone will be described. The diaphragm 11 is vibrated by the sound wave S. When it is
displaced back and forth, as shown by a broken line in FIG. 1 (a), the diaphragm 11 and the light
source 12 interlocked therewith change simultaneously back and forth. Therefore, the irradiation
circle 11c shown by a solid line in FIG. 1 (b) is always constant and does not change. However,
05-05-2019
2
since the distance between the diaphragm 11 and the light receiving unit 13 changes only by the
displacement amount of the diaphragm 11, the reflected light receiving portion 13a of the light
receiving unit 13 has the diaphragm 11 of FIG. The inside and outside of the reflected light
receiving portion 13a indicated by the solid line changes like a concentric circle indicated by the
broken line.
That is, the vibration plate 11 increases as the distance from the light receiving unit 13 increases,
and decreases as the vibration plate 11 approaches. The light receiving unit 13 formed of a
plurality of light receiving elements such as a CCD can convert the vibration of the diaphragm 11
into a digital electric signal by counting the number of light receptions of the light receiving
elements. FIG. 2 is a block diagram for inputting a music signal from the microphone of the
present invention to a digital audio device. In the figure, the sound wave S is converted into a
digital electric signal by the microphone 14 according to the present invention to which the
sound wave S is input, and is input through the transmission line 15 to the digital audio device
16 indicated by a dashed frame in the drawing. In the digital audio device 16, the latch circuit 18
temporarily holds the input digital electric signal at a constant interval by the latch clock signal A
based on the sampling frequency output from the clock generator 17, and then the digital music
signal B is generated. Output as This digital music signal B is equivalent to the digital music
signal E shown in FIG. In addition, if the diaphragm 11 of the microphone has the characteristics
of a low-pass filter having a cutoff frequency equal to or less than 1/2 of the sampling frequency
when the output signal of the microphone is processed by the digital audio device, sampling can
be performed. No aliasing distortion occurs due to the accompanying alias effect. (Effects of the
Invention ') As described above, according to the present invention, digital electrical signals
necessary for digital audio equipment can be obtained with a circuit configuration which is much
simpler than that of processing by a conventional analog-to-digital converter. You can get Also,
since the output of the microphone is a digital electrical signal, there is no mixing of noise during
transmission to other devices, and no amplifier is required, so no distortion occurs other than the
distortion generated by the microphone itself.
[0002]
Brief description of the drawings
[0003]
1 (a), (b) and (Q) are respectively a side sectional view of the microphone according to the
present invention, a rear sectional view cut along AA 'and a front sectional view cut along BB',
FIG. FIG. 3 is a block diagram showing a method of supplying music signals from the microphone
05-05-2019
3
according to the present invention and the conventional microphone to the digital audio
equipment, respectively.
1.14: microphone 2 .: microphone amplifier 3.15: transmission line 4.16: digital audio device 5:
amplifier 6, 6: low pass filter 7, 17 ... Clock generator, 8 ... sample and hold amplifier, 9 ... analog
to digital converter, 10 ... housing, 11 ... diaphragm, lla ... absorption or transmission part, Ilb ...
Reflective part, llc ... Irradiated circle, 12 ... Light source, 13 ... Photodetector. 13a: reflected light
receiving circle, 18: latch circuit. Patent applicant Matsushita Electric Industrial Co., Ltd. (b) (c)
10,-housing 'a 11-,-JMQIL 11a-aFjcM3. Also, + tlUn +> 11b-0 counter-bearer 11c-Jkl, Karako Fi
12-, L-no λ 13-accommodating p13a-reflective antecedent Ll: 117 FIG. -Myglophone 15,..., "I"
"Mizudani valley 16,--1"; Taru 4-de I machine answer 17-Kuro Tsuku teacher basis 18--,, [] Path
[3] Lj Microphone / 2-, Microphone 趨 Black 3-IL Approx. 4-, Digital Audio 旧 Old 器 器 5-0
Amplifier 6-Loop Input Filter 7-Kuro Tsuk
05-05-2019
4
1/--страниц
Пожаловаться на содержимое документа