JPS62210799A - Camera integral type video tape recorder - Google Patents

Abstract

PURPOSE:To relax constraint for the mounting position, etc., of a microphone or a sounding body, by providing an informing sound cancelling means, and an automatic sensitivity adjuster, cancelling an informing sound from the sounding body inputted from the microphone in a recording time, and varying the sound volume interlocking with the automatic sensitivity adjuster. CONSTITUTION:When the signal of a control signal input terminal 12 is put in a recording state, a variable gain signal generator 5 generates a specific signal shown in figure (a). At such a time, a microphone 3 collects the informing sound, and a signal having a waveform shown in figure (b) appears at the output side of a variable gain amplifier 10. The signal is changed to a signal waveform shown in figure (c), the phase of which is inverted from, and the amplitude of which is equal to the signal waveform in figure (b), and the signal waveform represented in figures (b) and (c) are added at an adder 8, then being cancelled, and the informing sound is not recorded on a magnetic head 11. Meanwhile, an automatic sensitivity adjuster 9 varies the amplification degree of the variable gain amplifier 10 based on the size of a sound signal component, simultaneously, varies the gain of the variable gain signal generator 5. Therefore, the sound volume fitted for a peripheral status can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a camera-integrated videotape recorder (hereinafter referred to as movie) K having means for confirming a recording standby state and a recording operation state.

[Conventional technology]

Figure 3 is Utility Application No. 60-3582, which is the applicant's prior art.
FIG. 2 is a perspective view showing an example of a conventional movie shown in No. 0; In the figure, (1) is the movie main body, (2) is a selection switch for movie recording and recording standby, (3) is a microphone, and (4) is a sounding body.

Next, the operation will be explained. When the selection switch (2) is selected, the first sounding element (4) generates a notification sound when the movie is in the recording state. Therefore, the operational status of the movie can be confirmed by ear, and operability is improved.◇ [Problem to be solved by the invention] However, in the conventional method, the microphone (3) is not connected to the sound source (4). Since it picks up the notification sound, installing the first sounding body (4) is subject to restrictions on position and volume, or the microphone (3) can be made more directional to pick up the notification sound of the first sounding body (4). There was a problem in that we had to devise ways to prevent this from happening.

This invention was made to solve the above-mentioned problems, and it is easy to install the sounding body and microphone that generates the notification sound, and it also makes it possible to create an easy-to-use movie that can alleviate the restrictions on the volume of the notification sound. [Means for solving the problem] The movie according to the present invention includes a notification sound canceling means for canceling a notification sound signal picked up by a microphone,
An automatic sensitivity adjuster is provided to control each gain of a variable gain amplifier connected to the microphone and a variable gain signal generator that drives the sounding body according to the magnitude of the audio signal picked up by the microphone p*ν. It is something.

[Effect]

In this invention, since the notification sound of the sounding body picked up by the microphone is canceled, the positional restrictions on mounting the microphone and the sounding body are relaxed.

The automatic sensitivity adjuster works to ensure that an appropriate notification volume is always obtained depending on the surrounding noise situation.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of a movie according to the present invention.

In the figure, (3) is a microphone, and (4) is a sounding body.

(5) is a variable gain signal generator connected to a control signal input terminal (described later) to drive the sounding body (4); (6)
is a phase inverter connected to a variable gain signal generator (5);
(7) is a gain adjuster connected to the phase inverter (6), (
8) is an adder connected to a gain adjuster (7) and a variable gain amplifier to be described later, and together with the phase inverter (6) and the like, constitutes a notification sound canceling μ means (100). (9) is an automatic sensitivity adjuster that controls the gains of a variable gain signal generator (5) and a variable gain amplifier to be described later. The head is a variable gain amplifier (11) connected to the microphone (3), and the magnetic head (12) is a control signal input terminal connected to the variable gain amplifier (10) via an adder (8). , a recording standby signal, or a recording state signal is input.

Next, the operation will be explained. Now, when the signal at the control signal input terminal (12) is in a recording standby state, the variable gain signal generator (5) does not generate a signal.

It operates as a normal movie audio circuit.

In other words, the audio signal picked up by the microphone (3) is adjusted by the automatic sensitivity adjuster (
9) and a variable gain amplifier (10), and the magnetic head (11)K is sent out.

Naturally, the magnetic head (11) is not recording any signals at this time.

Next, a description will be given of when the signal at the control signal input terminal (12) is in the recording state. At this time, the variable gain signal generator (5) generates a specific signal (here, as an example, a sine wave) shown in the second factor.

This signal is generated by the sounding element (14) as a notification sound, allowing the operator to know that the movie is being recorded. At this time, the microphone (3) picks up the notification sound. , the output side of the variable gain amplifier (10) is as shown in Fig. 2 (
A signal with the waveform shown in b) appears.

Although this signal waveform appears in a form superimposed on other audio signal components, it is shown here for ease of understanding.

Audio signal components are omitted. On the other hand, the variable gain signal generator (5) supplies a signal (here a sine wave) to the phase inverter (6). This signal is processed by the gain adjuster (7) as shown in Figure 2 (
The signal waveform in the same figure (e) has an inverted phase and the same amplitude as the signal waveform in b).
) is the signal waveform. The signal waveforms shown in FIGS. 2(b) and 2(0) are canceled by being added by the adder (8), and no notification sound is recorded on the magnetic head (11).

Further, the automatic sensitivity adjuster (9) changes the amplification degree of the variable gain amplifier (10) depending on the magnitude of the audio signal component, and at the same time changes the gain of the variable gain signal generator (5). When the 0frf level around the microphone (3) is high and the audio signal component is large, the notification sound is made louder; conversely, when the noise level /I/ is low and the audio signal component is small, the notification sound is made smaller. . Therefore, the volume of the notification sound can be obtained depending on the surrounding situation.

In the above embodiment, the notification sound canceling means (100
), a single phase inverter (6), a gain adjuster (7), and an adder (8) were used, but the invention is not limited to this.
For example, a subtracter such as a differential amplifier whose subtraction amount can be set arbitrarily may be used. Further, the signal generated by the variable gain signal generator (5) is other than a sine wave.

For example, even if the signal is intermittent, the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, the notification sound from the sounding body that comes in from the microphone at the time of recording is canceled by, for example, adding a signal with an opposite phase, and the volume of the notification sound is adjusted to the automatic sensitivity adjuster. Since it is configured to be variable in conjunction with each other, the operator can easily check the operating status of the movie by ear without being affected by the surrounding noise level, and it also has the effect of easing restrictions such as the mounting position of the microphone and sounding body. There is.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the camera-integrated videotape recorder according to the present invention, and FIGS. 2(a) to (e)
1 is a signal waveform diagram of each part in FIG. 1, and FIG. 3 is an external perspective view showing a conventional camera-integrated video tape recorder. (3
)...Microphone, (4)・-R plaster, (5)・
...Variable gain signal generator, (9)...Automatic sensitivity adjuster, (10)...Variable gain amplifier% (12)...Control signal input terminal, (100)...Notification sound canceling means . In addition, in FIG. 1, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) a variable gain signal generator that activates a sounding element when a recording state signal is input to a control signal input terminal; and a variable gain amplifier connected to a microphone;
an automatic sensitivity adjuster that controls each gain of the variable gain amplifier and the variable gain signal generator according to the magnitude of the audio signal picked up by the microphone; and an alert sound signal from the sounding body picked up by the microphone during recording. A camera-integrated video tape recorder is provided with a notification sound canceling means for canceling the notification sound. (2) The camera-integrated video tape recorder according to claim 1, wherein the notification sound canceling means is constituted by a circuit that can count the output signal of the variable gain signal generator in reverse phase to the signal from the microphone. .