JPS583529B2 - Microphone directivity adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microphone directivity adjustment device, and more particularly to a novel configuration in which the directivity of a microphone used in conjunction with a camera such as a cine camera can be changed in relation to a focus operation or a zoom operation.

Microphones for tape recorders and the like used in conjunction with cine cameras, video cameras, etc. are generally of blunt directivity so as to collect sounds from all surrounding directions.

Therefore, when photographing a distant object and trying to collect low-pressure sound from a distant sound source, it is necessary to collect sound from the camera itself, such as the film winding device, or from a sound source near the camera. The microphone must be placed far enough away from the camera to avoid being masked by high-pressure sound, so the photographer can quickly change the sound source to respond to sudden changes in the shooting direction or position. There was the inconvenience of not being able to do that.

The present invention was made with this in mind, and the directivity of the microphone is adjusted according to the rotation of the focus ring or zoom ring, thereby making it possible to set the microphone close to the camera when photographing a long-distance target. This system is designed to effectively collect low sound pressure sounds from distant sound sources, such as film winding sounds, without being masked by nearby sound sources.

Hereinafter, the present invention will be explained using the drawings.

FIG. 1 is a side view of a cine camera section according to an embodiment of the present invention, and FIG. 2 is a sectional view of essential parts of the cine camera section. A focus ring 1 and a zoom ring 3 are attached to a lens barrel 2 of the cine camera. has been done.

Three types of annular conductors L1 to L6 and L7 to L having different lengths are arranged on the outer peripheral surface of the lens barrel 2 via an insulating sheet 4.
12, L13 to L18 are arranged, while the conductors L1 to L6, L7 to L12 are arranged on the inner peripheral surface of the focus ring 1.
, L13-L18, sliders S1-S6, S7-S12, S13-S18 are arranged so as to be in pressure contact with each other, and the sliders S1-S6, S7-S12, S13-
Sts and the conductors L1 to L6, L7 to L12, L13 to
L18 are switches SW1 to SW6 and SW7 to s, respectively.
w12, Sw13 to Sw18 are formed.

FIG. 3 shows the switches SW1 to SW6, SW7 to SW,
2. It is a developed view for explaining the operation of SW13 to SW18, and when the focus ring 1 is rotated, the sliders S1 to S6, S7 to S12, S13 to S18 change to the corresponding conductors L1 to L6, L7 to Moves on L12, L13 to L18 or an extension thereof, and switches SW1 to SW6, sw7 to SW12, SW13 to
All of SW18 are closed, and in the range of rotation angle θ1 to θ2, switches SW1 to SW6 to SW7 to SW12 are closed.
Furthermore, in the range of rotation angle θ2 to θ3, switches SW1 to
Only SW6 is formed to be closed.

FIG. 4a is a front view of a microphone section according to an embodiment of the present invention, and FIG. 4b is a cross-sectional view of a main part of the same microphone section. It is composed of piezoelectric film circular vibrators A1 to A6, B1 to B6, C1 to C6, which are arranged concentrically and radially as shown in the figure, and other holding members (not shown).

FIG. 4C is a pattern diagram showing the directivity in a plane including the main axis M of the microphone. In the figure, curve P1 is the composite directivity pattern of the circular oscillators A1 to A6, and curve P2 is the composite directional pattern of the circular oscillators A1 to A6. Composite directivity pattern of A1-A6, B1-B6, curve P3 is circular oscillator A1-A6, B1-B6, C
1 to C6 are shown, respectively.

FIG. 5 is a block diagram of main parts in the output section of the microphone, and in the figure, circular vibrators A1 to A6, B1 to
The outputs of B6, C1 to C6 are respectively connected to the switch SW1.
~SW6, SW7~SW12, SW13~SW18 and buffer circuits E1~E6, E7~E12E13~E18
are combined after passing through amplifiers F1, F2, F3, respectively.
is input.

The signals are further combined at the output terminals of amplifiers F1, F2, and F3, and input to amplifier F4.

In the embodiment configured as described above, first, when photographing a subject at a short distance, if the rotation angle θ of the focus ring 1 is between 0≦θ≦θ1, the switches SW1 to SW6, S
W7 to SW12 and SW13 to SW18 are all closed, and the combined directivity of the microphone has a similar pattern as shown by curve P3 in FIG. 4C.

Therefore, when photographing a subject at a short distance, a wide range of echo sounds is collected.

Next, when photographing a medium-distance object, that is, when the rotation angle θ of the focus ring 1 is between θ1<θ≦θ2, the switch SW1
~SW6, SW7~SW12 are closed, but switch S
Since W13 to SW18 are open, the combined directivity of the microphone shows a slightly sharper pattern than when photographing a subject at a close distance, as shown by curve P2 in Figure 4C, and the sensitivity of the microphone to sound sources other than the direction of the main axis is reduced. decreases slightly.

Furthermore, when photographing a long-distance object, that is, when the rotation angle θ of the focus ring 1 is in the range θ2<θ<θ3, the switch SW
Only switches 1 to SW6 are closed, and switches SW7 to SW12 and S
Since W13 to SW18 are open, the combined directivity of the microphone is much sharper than when photographing a target at a medium distance, as shown by curve P1 in Figure 4C, and the sensitivity of the microphone to sound sources other than the direction of the main axis is significantly reduced. do.

As described above, according to the present invention, when photographing a subject at a close distance, the directivity of the microphone becomes very dull as in the conventional case.
Not only can it collect a wide range of surrounding sounds, but when shooting objects at a long distance, the directivity of the microphone becomes extremely sharp as the focus ring 1 rotates, so even if the microphone is placed near the camera, it will not be difficult to wind the film. Low sound pressure sounds from distant sound sources can be collected well without being masked by sounds.

Therefore, by fixing the microphone to the camera or placing it near the camera, the photographer can quickly change the sound source that collects sound even if the camera suddenly changes the shooting direction or shooting location, and the effect is Remarkable.

In the embodiment, the switch was formed by the first member attached to the outer surface of the lens barrel and the second member attached to the inner surface of the focus ring, but the switch was formed by the first member attached to the outer surface of the lens barrel. and a second member attached to the inner surface of the zoom ring, the directivity of the microphone can be changed in response to the zoom operation, and the same effect can be obtained.

[Brief explanation of drawings]

Figure 1 is a side view of the cine camera section in one embodiment, and Figure 1 is a side view of the cine camera section in the first embodiment.
The figure is a sectional view of the main parts of a cine camera, and Figure 3 is switch SW1.
~SW6, SW7~SW12, SW13~SW18 development view, Figure 4a is a front view of the microphone section in one embodiment of the present invention, Figure 4b is a sectional view of the main part of the microphone, Figure 4C is the microphone FIG. 5 is a block diagram of the main parts of the output section of the microphone. 1...Focus ring, 2...Lens barrel, 3...Zoom ring, 4...Insulating sheet, 5...Substrate, A1...A
6, B1...B6, C1...C6...Circular vibrator, L1...L18...Conductor, S1...S
18...Slider, SW1...SW18...Switch, E,
...E18...Buffer circuit, F1...F4...Amplifier.

Claims (1)

[Claims] 1 A first member attached to the outer surface of the lens barrel and a second member attached to the inner surface of the focus ring or zoom ring, and a plurality of switches that open and close according to the movement of the focus ring or zoom ring, and a curved surface. Equipped with a microphone that synthesizes the output of multiple arranged vibrators,
A microphone directivity adjustment device, characterized in that the switch is arranged in an output circuit of each vibrator so that the microphone directivity can be changed according to movement of a focus ring or a zoom ring.