JP2000004493A - Video camera - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a video camera capable of improving sound collection performance under shooting conditions in which a subject moves in a shooting frame. SOLUTION: A gain control section 9 as a microphone directivity control section automatically controls a line gain of a stereo microphone 6 based on an output of a motion detection section 5 which calculates image data and detects a moving direction of a subject. To correct the direction of the sound collection directivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound collecting section of a video camera.

[0002]

2. Description of the Related Art A conventional video camera 1 is configured as shown in FIG. The optical image captured via the zoom lens 2 is converted into an electric signal by the photoelectric conversion element 3 and output to the subsequent stage via the video signal processing unit 4 and recorded on, for example, a magnetic tape.

The stereo microphone 6 is a right channel microphone 6
R and a left channel microphone 6L. The respective outputs are input to the audio signal processing unit 8 via the amplifiers 7R and 7L, and are recorded on the magnetic tape.

There is also a type in which the directivity of the stereo microphone 6 is switched between wide and narrow in conjunction with the zoom of the zoom lens 2.

[0005]

In such a configuration,
The width of the directivity of the stereo microphone 6 is increased or decreased in conjunction with the zoom of the zoom lens 2 to improve the sound collection performance. At present, it is not possible to expect improvement in sound collection performance under shooting conditions such as moving inside.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a video camera which can be expected to improve sound collecting performance under photographing conditions in which a subject moves in a photographing frame.

[0007]

A video camera according to the present invention detects the movement of a subject from a video signal and automatically controls a stereo microphone so that the direction of sound collection directivity moves in the moving direction of the subject. It is characterized by.

According to the present invention, it is possible to improve the sound collecting performance under photographing conditions in which a subject moves in a photographing frame.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The video camera according to the first aspect of the present invention
In a video camera in which a stereo microphone is arranged so as to collect sound of a shooting frame, a motion detection unit that calculates a processed image data and detects a moving direction of the subject,
Microphone directivity control means for automatically controlling the stereo microphone so that the direction of the sound collection directivity moves in the moving direction of the subject detected by the motion detection unit is provided.

[0010] The video camera according to the second aspect is the first aspect.
, A microphone directivity control means for changing the gain of each microphone line of the left microphone and the right microphone constituting the stereo microphone so that the sound collection directivity moves in the moving direction of the subject detected by the motion detection unit. It is characterized by comprising a control unit.

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a video camera of the present invention. It is to be noted that components having the same operations as those in FIG.

The microphone directivity control means for moving the direction of the sound collecting directivity in the moving direction of the subject detected by the motion detecting section 5 includes gains of the amplifiers 7R and 7L according to the position of the subject detected by the motion detecting section 5. Is configured by a gain control unit 9 that controls the gain.

More specifically, the motion detecting section 5 is, for example, an MP.
EG (Moving Picture coding Experts Group)
Performs motion detection used in standard-based image compression. In this motion detection, the screen is divided into small blocks as shown in FIG. 2, and a motion vector (movement direction and motion amount) is detected for each block. For this reason, as shown in FIG. 2, only the moving part in the screen can be extracted, and the direction of the directivity of the microphone can be matched to the moving subject.

As shown in FIG. 3, the video camera 1 is set, and from the position (I) to the position (II) through the position (II).
When photographing the subject 10 moving to I), the gain of each microphone line is changed as shown in FIG.

At the position (II) where the subject 10 is captured at the center position of the photographing frame, the gains A1 and A2 of the amplifiers 7R and 7L are set to the same A1 = A2 = G2 and viewed from the video camera 1. The direction of the sound collection directivity in the horizontal direction of the stereo microphone 6 faces the front B2, and the stereo microphone 6 captures the subject 10 at the position (II).

In the case of the position (I) before the object 10 moves to the position (II), the gains A1,
A2 is A1 = G3 (where G3> G2
), A2 = G1 (G1 <G2), and the direction of the horizontal sound collection directivity of the stereo microphone 6 viewed from the video camera 1 is directed to the right side B1 and the stereo microphone 6 is positioned at the position (I). The subject 10 is being captured.

The subject 10 is moved from the position (II) to the position (III).
When the gain A1, the gains A1,
A2 is set to A1 = G1 and A2 = G3, and the direction of the horizontal sound collection directivity of the stereo microphone 6 viewed from the video camera 1 is directed to the left side B3, and the stereo microphone 6 is the subject at the position (III). Catch 10

As described above, the direction of the sound collecting directivity of the stereo microphone 6 is automatically changed by the gain control unit 9 according to the position of the subject 10, so that the sound generated by the subject 10 can be more clearly displayed than before. Can be recorded.

[0019]

As described above, according to the present invention, the movement of the subject is detected from the video signal, and the stereo microphone is automatically controlled so that the direction of the sound collecting directivity moves in the moving direction of the subject. Can improve the sound collection performance under shooting conditions such as moving within a shooting frame.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a video camera according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating the principle of a motion detection unit according to the embodiment;

FIG. 3 is an explanatory diagram when a subject passes from right to left in a shooting frame according to the embodiment;

FIG. 4 is a diagram showing a change in line gain of the stereo microphone according to the embodiment;

FIG. 5 is a configuration diagram of a conventional video camera.

[Explanation of symbols]

 Reference Signs List 2 zoom lens 3 photoelectric conversion element 4 video signal processing unit 5 motion detection unit 6 stereo microphone 6R right channel microphone 6L left channel microphone 7R, 7L amplifier 8 audio signal processing unit 9 gain control unit (microphone directivity control means) 10 subject A1 , A2 Amplifier 7R, 7L gain

Claims (2)

[Claims] 1. A video camera in which a stereo microphone is arranged so as to collect sound of a photographing frame, a motion detecting section for calculating a photographed image data and detecting a moving direction of a subject, and a motion detecting section detecting A video camera comprising: microphone directivity control means for automatically controlling the stereo microphone so that the direction of sound collection directivity moves in the direction of movement of a subject. 2. A microphone directivity control means for controlling a gain of each of microphone lines of a left microphone and a right microphone constituting the stereo microphone so that the sound collecting directivity moves in the moving direction of the subject detected by the motion detecting unit. 2. The video camera according to claim 1, comprising a variable gain control unit.