JPH03151800

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DESCRIPTION JPH03151800
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
audio recording method adapted to an image in a television camera, a movie camera, a VTR
integrated camera or the like. 2. Description of the Related Art In the conventional voice
recording system, two microphones having different directivity are manually switched. FIG. 4 is a
view showing the configuration of a conventional microphone, which comprises a directional
microphone 15 and an omnidirectional microphone 16, and the two microphones are switched
manually. As this kind of thing, for example, those described in Television Technology, March,
1989, page 59 can be mentioned. [Problems to be Solved by the Invention] In the abovementioned prior art, there is a problem that the user has to switch by himself, which is
bothersome and it is difficult for the beginner to switch properly. An object of the present
invention is to provide a recording method that automatically switches microphones that are
always appropriate under various shooting conditions. [Means for Solving the Problems] The
above object is to detect a distant object or to photograph an object within a narrow range by
increasing the magnification of the lens, and accordingly, plural microphones are detected. This
is achieved by narrowing and automatically switching the directivity. [Operation] The directivity
of the microphone is switched to the narrow one when it is detected that the object is far or when
it is detected that the magnification of the lens is large. This reduces the possibility of distant
sounds being disturbed by nearby sounds. Also, when the magnification of the video increases,
the sound in the range that matches the video to be recorded is mainly recorded. In this manner,
the directivity of the microphone can be switched automatically, so that the photographer does
not have to switch by himself. Embodiments of the present invention will be described below
with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a
microphone recording system according to the present invention, in which voice is converted
into an electrical signal by a narrow directional microphone 1 and a wide directional microphone
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2 and a variable mixer 3 The signals are mixed at a certain ratio and output to the audio output
terminal 5 through the audio circuit 4. The image passes through the lens 6 to form an image on
the light receiving unit 10, passes through the image circuit 11, and is output to the image
output terminal 12. The distance to the object (subject) is detected as the rotation angle of the
ring of the lens for focusing by detecting the in-focus position (focus position) of the lens 6, and
converting it into an electrical signal by the focus position detection circuit 7. , And input to the
microcomputer 9. Further, the magnification of the lens is detected as the rotation angle of the
ring of the lens that varies the magnification, converted into an electric signal by the lens
magnification detection circuit 8, and input to the microcomputer 9.
The microcomputer 9 determines the mixing ratio of the signals from the narrow directivity
microphone 1 and the wide directivity microphone 2 based on the respective data, and changes
the mixing ratio by the variable mixer 3. Fig. 2 is a characteristic diagram showing the directivity
· · · of two microphones with different directivity, and by changing the mixing ratio, wide
directivity microphone characteristics 14 to narrow directivity microphone characteristics]
directivity 3 6 can change the directivity of the microphone continuously to the characteristic.
FIG. 3 is a view showing an example of one variable characteristic of the mixing ratio of the
signals of the two microphones. The variation of the mixing ratio of the two microphones with
distance M) and lens magnification (change in focal length) is shown. Thereby, appropriate
directivity characteristics can be automatically obtained at all times in accordance with the
distance to the object and the magnification of the lens. [Effects of the Invention] As described
above, according to the present invention, according to the present invention, the voice can be
recorded by the optimum directivity characteristics without changing the switch, and the
problems of the above-mentioned prior art can be excluded. Can provide excellent performance
microphone recording method.
[0002]
Brief description of the drawings
[0003]
FIG. 1 is a block diagram showing one embodiment of a microphone recording system according
to the present invention, FIG. 2 is a characteristic diagram showing the directivity of two
microphones different in directivity, and FIG. 3 is a signal of two microphones. FIG. 4 is a
diagram showing an example of the variable characteristics of the mixing ratio, and FIG. 4 is a
diagram showing the configuration of a conventional microphone.
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1 · · Narrow directivity microphone, 2 · · · Wide directivity microphone. 3 ... variable mixer, 6 ...
lens. 7 ... focus position detection circuit, 8 ... lens magnification detection circuit. 9・・マイコン
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111 111 − 答 答 A: B: Mike l's issue number: My 72's it 2 di Figure
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