JPH0748623B2 - Recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device, and more particularly to a camera-integrated VTR.
For example, the present invention relates to a recording device that records voice with a microphone.

[Prior Art] FIG. 2 is a block diagram showing a circuit configuration for collecting sound from a conventional microphone and performing sound processing. A circuit configuration for collecting sound from a conventional microphone and processing the sound includes a microphone that takes in sound, for example, an electret condenser microphone (an insulating material such as Teflon (registered trademark) or polypropylene processed so as to semi-permanently hold an electrostatic charge). Microphone using high resin: hereinafter abbreviated as a microphone) 1, a high-pass filter (H / P / F) 5 for extracting only high-frequency components of a sound signal taken from the microphone 1, the circuit at the time of recording Switching means 3 that can be manually set by the user to be a circuit for removing wind noise, and in response to switching of the switching means 3, a sound signal is taken in from the A side during normal operation and from the B side when removing wind noise. Changeover switch 4, an amplifier 6 for amplifying a sound signal passing through the changeover switch 4 to an audible band, and a sound signal amplified by the amplifier 6 to a constant level. An automatic gain control circuit (hereinafter referred to as AGC circuit) 7 for dynamically controlling gain, a control circuit 8, a drive 9 for inputting and outputting a sound signal whose gain is controlled to a constant level, and a current change from the drive 9. Which receives a magnetic field and converts it into a change in magnetic amount to magnetize and record a magnetic recording medium such as a magnetic tape.
Including 10.

In the circuit that collects sound from the conventional microphone configured as described above and performs sound processing, when the user determines that there is wind during recording and it is captured as noise, it will interfere with recording,
The switching means 3 is manually set so as to remove wind noise, and accordingly the changeover switch 4 switches the switch from the A side to the B side so that only the HP / F5 passing signals are recorded. I tried not to record wind noise, which is a low frequency component.

[Problems to be Solved by the Invention] However, in the circuit for collecting and processing sound from the conventional microphone shown in FIG. 2, wind noise during recording is detected by human sense, or the microphone amplifier output is heard by earphone. If the landscape is always disguised, such as outdoors, the manual operation of the switching means 3 shown in FIG. 2 becomes very complicated because the detection method is used. In addition, the microphone is usually wrapped in polyurethane with open cells called windshield for the purpose of preventing the collection of wind noise.
When the windshield is used and the characteristics of the microphone are slightly changed or the wind becomes strong, wind noise such as rumbling noise is picked up through the windshield and it is difficult to hear. Further, wind noise is generally a sound in the low frequency range, and when it becomes too loud, the automatic gain control explained in FIG. 2 operates effectively against this wind noise, and sounds other than wind noise are completely absorbed. There was also the problem of not being able to make sounds.

Therefore, a main object of the present invention is to provide a recording apparatus capable of automatically removing wind noise when recording through a microphone.

[Means for Solving the Problems] A recording apparatus according to the present invention is provided with a first microphone means for collecting a sound to be recorded, and a sound recorded by the first microphone means. Sound processing means for processing, second microphone means, connected to the second microphone means,
From the low-pass filter means for extracting only the low-pass component of the output from the second microphone means, the detecting means for detecting that the output from the low-pass filter means exceeds a predetermined level, and the detecting means. In response to the detection output of
And a high-pass filter means interposed between the microphone means and the sound processing means.

[Operation] According to the present invention, the same sound signal is picked up by two microphones in parallel, the one microphone is used for wind noise detection, and the other microphone is used for normal sound pickup to detect wind noise. Depending on the level of the wind noise detected by the microphone for recording, the low frequency component which is the wind noise in the sound signal detected by the microphone for normal sound collection is removed and only the high frequency component is controlled and recorded. I am trying to do it.

[Embodiment] FIG. 1 is a block diagram showing a circuit configuration for collecting sound from a microphone and processing sound according to an embodiment of the present invention. The improvement in comparison with the circuit configuration for collecting and processing sound from the conventional microphone shown in FIG. 2 is that the function of the conventional manual switching means 3 is accommodated in the microphone case 13 in the present invention. The new microphone 2 and the low-pass filter (L / P / F) 11 that extracts only the low-frequency components of the sound signal captured by the microphone 2 and the level detector 12 that detects the output level of L / P / F11 In response to the detection result of the level detector 12, the changeover switch 4 is automatically changed over, and the manual operation performed by the manual changeover means 3 is automated.

Next, with reference to FIG. 1, a circuit configuration and an operation for collecting sound from a microphone and performing sound processing will be described with respect to an embodiment of the present invention. The microphone 1 and the microphone 2 are housed in the same microphone case 13 and collect the same sound signal. However, the microphone 1 is used for normal sound collection, and the microphone 2 has a sound collecting characteristic of a low frequency range signal in particular. Excellent Use for wind noise detection. Next, the operation of the circuit will be described.

First, the sound signal that remarkably includes the characteristics of the low-frequency component detected by the microphone 2 that collects sound in parallel with the microphone 1 is L · P · F11.
Sent to. The sound signal that has passed through L / P / F11 is transmitted to the level detector 12 by sharpening the low frequency component, which is wind noise. The level detector 12 detects whether or not the input low-frequency component has reached a predetermined noise level that interferes with recording, and sends this detection level to the changeover switch 4 as a changeover signal. There is. If the wind noise does not reach a level that does not cause a problem, that is, a predetermined noise level, the changeover switch 4 is switched to the A side. If the detected level of the input wind noise has reached the level of noise that interferes with recording, the changeover switch 4 can be switched to the B side. When the changeover switch 4 switches the switch to the B side, the sound signal picked up by the microphone 1 is not directly taken in, but is temporarily changed to H · P · F5.
The sound signal that passes through will be captured. Signal is HP
Passing F5 removes and suppresses low-frequency components, which are wind noise, and sharpens high-frequency components of the sound signal. The sound signal passing through the above H / P / F5 is B of the changeover switch 4.
From the side to the amplifier 6. Thereafter, the amplifier 6 to the head 10 are processed by the same circuit as in the conventional case described in FIG.

As described above, the microphone 2 is installed and only the low frequency component is extracted by L / P / F11. When the level reaches a certain level, the changeover switch 4 is switched to the B side and the high frequency component of the sound signal is extracted. By incorporating this, clear recording with wind noise automatically removed becomes possible.

The recording apparatus according to the present invention is suitable for a camera-integrated VTR, but is also suitable for being used as a general recording apparatus alone.

[Advantages of the Invention] As described above, according to the present invention, when a constant level of wind noise is detected, the sound pickup circuit of the microphone automatically receives HPF.
Since the wind noise in the low frequency range is removed via the recording, there is no manual switching operation for removing wind noise during recording as in the past, and only wind noise is recorded. Since this problem is solved, there is an effect that recording outdoors can be done easily and clearly.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration for collecting sound from a microphone and performing sound processing according to an embodiment of the present invention. FIG. 2 is a block diagram showing a circuit configuration for collecting sound from a conventional microphone and performing sound processing. In the figure, 1 and 2 are microphones, 3 is changeover means, 4 is changeover switch, 5 is HPPF, 6 is amplifier, 7 is AGC circuit, 8 is control circuit, 9 is drive, 10 is head, 11 Is L / P /
F and 12 are level detectors and 13 is a microphone case. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A first microphone means for collecting a sound to be recorded, a sound processing means for processing a sound collected by the first microphone means, and a second microphone. Means, low-pass filter means connected to the second microphone means for extracting only low-pass components of the output from the second microphone means, and output from the low-pass filter means exceeding a predetermined level. Detection means for detecting that the output from the first microphone means is high-pass filter means for extracting only the high-frequency component of the output, and the output from the low-pass filter means exceeds the predetermined level. A switching means for selecting the output of the high-pass filter means when the detecting means detects it, and the output of the first microphone means when not detecting the output, and for giving it to the sound processing means. Recording Location.