close

Вход

Забыли?

вход по аккаунту

?

JPH03139096

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 JPH03139096
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
microphone recording system suitable for use in video cameras, VTR integrated cameras, and the
like. [Prior Art] A microphone is attached to a video camera and a VTR integrated camera, and a
sound is recorded together with an image of a subject. Among these video movies, "TV
Technology J: March 1983 issue. As described in page 59 and as shown in FIG. 3, it has two
microphones, a directional microphone 50 and a nondirectional microphone 51, and these two
microphones 50.51 are manually switched and selected according to the situation, For example,
it is known that the wind noise can be reduced and recorded by using the nondirectional
microphone 51 in a windy place. [Problems to be Solved by the Invention] By the way, in the
above-mentioned prior art, the user has to judge the recording environment at the time of
recording by himself and manually switch the microphone, which makes the operation
bothersome. There was a problem that it was difficult for beginners to make an appropriate
decision. In addition to the directional microphone 50, the above-mentioned prior art mainly
attaches a non-directional microphone 51 in addition to the directional microphone 50 mainly
for the purpose of enabling relatively clear recording even in strong winds. No matter how much
attention is given to the point of always controlling the balance between the sound in the center
of the screen and the sound in the surrounding area (the sound of things not captured in the
screen or those in the peripheral part of the screen) according to the situation. Was not paid. The
present invention has been made in view of the above points, and the object of the present
invention is to provide a microphone recording system capable of automatically keeping the
balance between the target sound and the surrounding sound always in a good state. It is to do.
[Means for Solving the Problems] In order to achieve the above-mentioned purpose, the
microphone recording system according to the present invention is installed to record a plurality
of microphones having different directivity or a certain direction of sound. It has a microphone
03-05-2019
1
and a microphone installed to record surrounding sounds, and changes the mixing ratio of the
signals of multiple microphones or outputs a signal based on the comparison result of the output
levels of the respective microphones It is made to make the switching selection of the
microphone. [Operation] For example, a directional microphone (narrow directional microphone)
directed to an object for mainly capturing a target sound and a non-directional microphone (or
wide directional microphone) for capturing one ambient sound are provided. The output signal
levels of the sounds captured by the two microphones are constantly compared by the
comparison circuit. Then, when it is determined that the ambient sound level is higher than the
target sound level by a certain level or more, the control circuit changes the mixing ratio of the
output signals from the directional microphone and the nondirectional microphone. Control the
variable mixing circuit to record the signal level from the directional microphone relatively larger
than that from the nondirectional microphone, or record only the output signal from the
directional microphone Switching control of the switching means.
In this way, it is possible to keep the balance between the main purpose sound and the
surrounding sound in a good condition at all times without the situation where the main purpose
sound is interrupted and not clearly recorded by the surrounding sound. . The invention will now
be described by means of an embodiment shown in FIGS. 1 and 2. FIG. FIG. 1 is a block diagram
showing the configuration of the main part of a VTR integrated camera, for example, to which the
microphone recording method according to the present invention is applied. In FIG. 1, reference
numeral 1 denotes a directional microphone disposed at a position facing the subject such as the
front of the device main body, and is provided to mainly capture the sound of the object at the
center of the photographing screen. An omnidirectional microphone 2 disposed at an appropriate
part of the device main body is provided to capture surrounding sounds, such as sounds of
sounds outside of the photographing screen, or in some cases, those around the photographing
screen. . Sounds captured respectively by the directional microphone 1 and the nondirectional
microphone 2 are converted into electric signals, and are sent to the audio circuit 3 and the
audio circuit 4 respectively. The output signals of the audio circuits ji 3 and 4 are sent to the
variable mixing circuit 5 and mixed by the variable mixing circuit 5 at a mixing ratio based on the
control signal from the control circuit 11 and then supplied to the gain adjustment circuit 6 The
gain is adjusted by the gain adjustment circuit 6 based on the control signal from the control
circuit 11, and thereafter, the signal is output from the output terminal 7 to the recording circuit
system of the subsequent stage. The outputs of the audio circuit 3 and the audio circuit 4 are
also sent to the detection circuit 8 and the detection circuit 9, respectively, subjected to detection
and DC voltage conversion respectively by the detection circuits 8 and 9, and then supplied to
the comparison circuit 10. Ru. The comparison circuit 10 compares the two detected voltages,
and the output signal level of the directional microphone 1 becomes smaller than the output
signal level of the nondirectional microphone 2 by more than a predetermined level. At the same
time to determine whether or not. The level difference at that time is determined and sent to the
control circuit 11. The control circuit 11 sends a mixing ratio control signal S1 to the variable
03-05-2019
2
mixing circuit 5 so as to variably set the mixing ratio of the outputs of the directional
microphone 1 and the nondirectional microphone 2 according to the comparison result from the
comparison circuit 10. , Change the mixing ratio of the outputs from the directional microphone
1 and the nondirectional microphone 2. Further, the control circuit 11 sends a gain control signal
S2 to the gain adjustment circuit 6 in order to adjust the level variation due to the variable
control of the mixing ratio by the gain adjustment circuit 6. In this embodiment, if the signal level
of the sound (target sound) captured by the directional microphone is larger than the sound
(ambient sound) captured by the nondirectional microphone 2 by a level difference of 8 dB or
more, two microphones are used. Keep the mixing ratio of the output signal of 1: 1 at 8 dB or
less, increase the mixing ratio of the directional microphone 1 accordingly, and change the
mixing ratio of the output signals of the two microphones to 8 = 1 It has become.
Incidentally, since both the target sound and the ambient sound are not continuous sounds, the
mixing ratio is variably set with a certain time constant. Also, when the ambient sound suddenly
increases, the ratio of the target sound increases, and the level of the target sound increases
accordingly, but the gain adjustment circuit 6 adjusts the gain to suppress the change to 2.8 dB
at maximum. And, it is considered to be able to record without discomfort. FIG. 2 is an
explanatory view showing the directional characteristics of the directional microphone 1 and the
nondirectional microphone 2, in which 12 is a characteristic by the directional microphone 1 and
13 is a characteristic by the nondirectional microphone 2. In the figure, 14 indicates the sound
source of the target sound, and 15 indicates the sound source of the ambient sound. In general
recording, it is desirable that the ambient sound be simultaneously recorded at a level where the
sound level of the target sound is sufficiently large and clear, and at the same time it does not
disturb it. Unfavorable is the generation of ambient sound near: g15, which is disturbed by the
ambient sound and reduces the clarity of the target sound. As described above, the target sound
is captured by the directional microphone 1 and the ambient sound is captured by the
nondirectional microphone 2. Therefore, as in the embodiment, the levels of the output signals of
the two microphones 1 and 2 are compared, and when it is determined that the level of the
ambient sound is greater than the level of the target sound by a certain standard, If the mixing
ratio is changed so that the signal level of the signal is relatively larger than that from the
nondirectional microphone, there is no case where the target sound is interrupted in the ambient
sound and the sound is not recorded clearly. The balance between the sound and the ambient
sound can always be kept in good condition. In the embodiment described above, the mixing
ratio of the directional microphone 1 and the nondirectional microphone 2 is variably controlled
so that the output signals of the two microphones 1 and 2 are always mixed. A switching /
mixing circuit having a mixing circuit function is provided instead of the mixing circuit 5, and
when the level difference between the output signals of the directional microphone 1 and the
nondirectional microphone 2 is equal to or more than a predetermined value As in the above
embodiment, the output signals of the two microphones 1 and 2 are mixed, while the level of the
ambient sound (the nondirectional microphone 2) is larger than the level of the target sound (the
03-05-2019
3
directional microphone 1) by a certain value or more When it comes to the switching function,
only the signal from the directional microphone 1 may be output to the subsequent circuit. Also
by doing this, the target sound is interrupted by the ambient sound and the sound can not be
recorded clearly. Situation to be avoided, such as. In the above embodiment, an example is shown
in which microphones having different directional characteristics are used in combination, but a
plurality of microphones having the same directional characteristics (for example, four), one of
which is an object (target sound generation source Setting the other three microphones to the
surroundings, automatically changing the mixing ratio of these microphones, or selectively
switching to record audio. The same effect as the embodiment can be expected.
[Effects of the Invention] According to the microphone recording method according to the
present invention as in the case of the rescuer, there is no case where the target sound is
interrupted in the ambient sound and the sound can not be recorded clearly. You can always
keep it in good condition. In addition, since there is no need to switch the microphone manually,
usability is improved, and even beginners can always record audio with an appropriate balance.
[0002]
Brief description of the drawings
[0003]
1 and 2 relate to an embodiment of the present invention, and FIG. 1 is a block diagram showing
the main configuration of an apparatus to which the present invention is applied, and FIG. 2 is a
directional microphone and a nondirectional microphone FIG. 3 is an explanatory view showing
one example of a conventional microphone.
1 ... directional microphone, 2 ... nondirectional microphone. 3.4 и и и audio circuit, 5 и и и variable
mixing circuit. 6 ... gain adjustment circuit, 7 ... output terminal. 8.9 ... detection circuit, 10 ...
comparison circuit. 11 и и и Control circuit, 12 и и и characteristics by the directional microphone.
13 и и и by the omnidirectional microphone. 14 иии Source of target sound, 15 иии Source of ambient
sound. 1st g и -1 1st tone! Fig. ?
03-05-2019
4
Документ
Категория
Без категории
Просмотров
0
Размер файла
13 Кб
Теги
jph03139096
1/--страниц
Пожаловаться на содержимое документа