вход по аккаунту



код для вставкиСкачать
Patent Translate
Powered by EPO and Google
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.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
digital speaker applied to a reproduction apparatus of POM (Pu1se Code Modulation) -ized audio
signal. Background art and its problems In recent years, also in the field of audio equipment,
audio signal) iPcM is treated and treated to improve the S / N ratio and expand the dynamic
range at the stage of recording the audio signal, 8 ? and amplification. Because there are various
merits such as reduction of non-linear distortion, PCM conversion of audio signals is eagerly
adopted. By the way, to digitize an audio signal waveform that is an analog signal, sampling is
performed at a repetition frequency twice the highest frequency included in the audio signal
according to the sampling theorem, and the sample link value is converted to a binary code.
Although it is known that it is sufficient, in order to reproduce the original audio signal from this
binary code, it is possible to have a D / A conversion function in any path of the reproduction
system. For this reason, digital speakers have been developed that perform D / A conversion
directly at the stage of electro-acoustic conversion. However, in the conventional digital speaker,
as shown in FIG. 1, the sound emitting portion ('..., Q') for each bit digit having a diaphragm area
in proportion to the weight of each bit digit of the parallel POM digital signal. Sound conversion
unit] (11 to 6 (to supply an audio POM signal, each sound generation unit produces a no-less
sound at a level proportional to the weight of each bit digit, and is additively synthesized in a
sound field (space, Digital / analog conversion is performed to generate analog sound. However,
since the sound generating units (11 to (6) in charge of each bit digit for generating an acoustic
output representing the weight of each bit digit are not identical at all, sound pressure frequency
characteristics or phases are generated between each sound generator. It causes an error in the
characteristic and further the propagation time, and it is difficult to cause a correct D / A
conversion (reproduction). In addition, once the weights of the sound generating units (II to ((1))
which are the electric-to-acoustic conversion units are determined, the reproduction of the POM
signals having different coding methods (weights) is not possible. In addition, since the sound
generating unit responsible for each bit is localized (-concentrated at the drop location), it is
difficult to perform correct D / A conversion. 0 Purpose of the Invention In view of such
conventional problems, the present invention corrects D PCM signals correctly. A / D conversion
is possible, and even for PCM signals with different coding schemes (weights), the weight is
changed according to the coding scheme to perform D / A modulation and dust reduction. There
is something to do.
A self-acoustic transducer is grouped and connected in parallel so as to have an oscillation area
proportional to each bin digit weight of the parallel PCM signal, and is driven for each bit digit.
Digital loudspeaker characterized in that each loop air-to-sound converter is a distributed A
device at substantially equal intervals. Because of this construction, it is extremely accurate]) / A
conversion performance is obtained G). The invention will now be described by way of example
with reference to the drawings. FIG. 2 shows the main part of the embodiment of the digital
speaker according to the present invention, and FIGS. 2 (a) and 2 (b) (a front view and FIG. 2 (a)
of a piezoelectric vibrator attached to a tP fi horn). AA cross-sectional view of FIG. Fig. 2 shows
that U ?? is a diaphragm formed of a body-shaped piezoelectric element, and each diaphragm
(11) has peripheral portions corresponding to its inner diameter and outer diameter fixed ring
(12), (13) The adjacent @ contact portions are coupled by a visco-elastic body (141 so that each
diaphragm 01) becomes an independent moving body. Each diaphragm (11) is disposed in a disk
shape (radial), and the whole is formed in a dome shape as seen in FIG. 2 (b). (15) is an electrode
made of a thin metal foil adhered or vapor-deposited to the front and back of the diaphragm U?.
The diaphragm [11] made of such a piezoelectric element generates a sound pressure by causing
an expansion and contraction action according to the voltage value by applying a voltage to an
electrode (1? (I5) which is formed in a surface and a class as known. Do. However, since the end
face of the vibration [1 ? is fixed by the fixing ring tiL (13), the distraction movement is a
movement in the thickness direction indicated by the dotted line, and a vibrating surface is
formed. Therefore, a digital speaker is formed by driving such vibration & 01) as a horn speaker
driver and driving each diaphragm (Ill with a binary code of parallel PCM digital signal) as
follows. That is, in the present invention, one diaphragm ulJ and electrodes 05 on both sides
thereof constitute a unit sounding body 06), and a solid sounding body (a-differentiated small
electro-acoustic transducer) (16) Are each driven independently and have identical sound
pressure frequency characteristics and identical phase characteristics. ) It is a thing that emits a
wrestling sound. Further, here, for example, as shown in FIG. 2 (a), CMSB) b i t combines one
sound generator ?6) into one set, and (MSB-1) bits make six sound generators (16). The
pronunciation part (I7) of each bit digit is the same as CMOB-2) biti li sounding body (assuming
Lfils are put together into one set every 1 group) as one set, and the pronunciation part (I7) of
each bit digit is The sounding bodies (161 are connected in parallel as many as the number
proportional to the weight number of the Gund digit) are configured as one loop.
And each roof. The sound producing bodies <16 + constituting the sound source are not used in
each loop as one or more sound producing bodies (16) distributed at substantially even intervals.
Therefore, the total number of the sound generator ? 61 is a necessity for the weight of each bit
digit of the PCM signal 0. Therefore, each sound generator of each bin digit of such grouped
(electric-voice note But there is no difference between the characteristics of each electric-tosound document conversion unit (17) (the nausea characteristics seen from the drive system and
the electro-acoustic conversion performance as a sound generator, Since the sound source is not
unevenly distributed, the characteristics as a whistle-to-tone converter having a D / A conversion
function are extremely good. FIG. 6 shows a drive circuit of one bit digit (for example, MSB). In
FIG. 3, when a pulse input is supplied to the input terminal 1, each of the transistors T1 and T2 is
turned on, and the terminal voltage of the resistor R1 constitutes each of the sounding members
(171 (17a) of the MSB digit sounding portion (17 (17a)). 16a) (in FIG. 2, each diaphragm 0 ? ?
which is applied to the sounding bodies a6 arranged approximately radially in a uniformly
distributed manner, ie, here, for example, every other one) and constitutes the sounding body
(16a) It is made to vibrate. -T-Vcc is a power supply. As for the other bit places, one group of
sounding members (16+ are driven in parallel as shown in FIG. 6) constituting them. Therefore, if
a parallel POM signal is added to n (n's sound generating units (17) corresponding to n bits,
sound elements in a radially distributed arrangement constituting the sound generating units of
valley pit digit which is bit engagement or 1 16) is all driven and driven valley sounding body
(16184 '? The valley diaphragm which makes it (IIJ is made to move, and a pulse sound is
emitted. Then, the pulse sound of the straw is added and synthesized in the sound field of space,
thereby performing D / A conversion and reproducing an analog sound. In the present
embodiment, although the case of the binary code has been mentioned as the coding scheme of
the parallel POM signal, the present invention is not limited to this and can be applied to any
coding scheme as well. In this case, the electro-acoustic transducers (sounders) are grouped to
form an electro-acoustic transducer (sound generator) so as to have a vibration area proportional
to the weight of the digit of the chord system. Therefore, in order to apply to another coding
system, it is good to simply change the number of combinations of sounding bodies. Each
sounding body (161) may be arranged in an IJ LUX-like zigzag pattern. Effects of the Invention
The present invention provides the following unique effects.
(1), even though the diaphragm area ratio representing each bit digit of the parallel POM signal
is proportional to the weight of the bit digit, the sound generator of each bit digit is a minute unit
sound generator, electro-acoustic Since the transducers are grouped by the number
corresponding to the vibration area proportional to the weight of the bit digit and connected in
parallel, the sound producing part of each bit digit has the electro-acoustic conversion
performance and the sound producing part seen from the drive system. Electrical characteristics
are equal. Therefore, good / A conversion performance can be obtained when reproducing an
audio signal. (2) The sound sources are not biased since the unit sound producing members
constituting each bit digit are evenly distributed. Therefore, D / A conversion can be correctly
performed when reproducing the audio signal, so that the reproduction quality of the audio
signal can be improved. (3t, even if the code system (N) of the POM signal changes, the number
of unit sounders to be driven can be changed freely, and thus any code system POM signal can
be coped with. (4) It is easy to manufacture because there is no need to form a large-area
sounding body.
Brief description of the drawings
FIG. 1 is an explanatory view showing an example of a main part of a conventional digital
speaker, and FIGS. 2 (a) and 2 (b) are a front view showing the main part of an embodiment of
the digital speaker according to the present invention and FIG. (A-A line sectional view of al, FIG.
6 is a circuit diagram showing an example of a drive circuit of the sound generation unit. In the
reference numerals used in the drawings, 06) иииииииииииииииииииииииииииииииииииииииииииииииииииииииииииии иииииии Sound generator
(electric-acoustic converter). Agent Saturn Katsura Tsunekage Toshiyuki Sugiura
Без категории
Размер файла
13 Кб
description, jps5995799
Пожаловаться на содержимое документа