JPH0626079B2 - Automatic recording method on recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) In the present invention, an IC memory is a recording medium such as a magnetic disk
The present invention relates to a method for writing a digital audio signal, and more particularly to an automatic recording method capable of effectively utilizing the recording capacity of a recording medium.

(Prior Art) Conventionally, in an automated machine factory,
2. Description of the Related Art There is known a device that, when an abnormality occurs in a process, detects the abnormality and issues a sound alarm to notify an operator of the abnormality.

Such an alarm device is equipped with an IC memory in which a plurality of notification contents are recorded in advance as a voice signal, and when a detection signal indicating the occurrence of an abnormality is input, a voice signal corresponding to the detection signal is generated. It is called from the IC memory and the alarm is issued by the speaker.

Conventionally, as a method of recording a plurality of notification contents in an IC memory, after amplifying a sound signal from a microphone, A /
It is performed to convert the digital signal into a digital signal by a D converter and write the digital signal in an IC memory by a known write control circuit.

Further, there is also adopted a method in which a plurality of notification contents are recorded in advance on a magnetic tape by using a tape recorder, and a reproduction signal of the magnetic tape is connected to the A / D converter when recording in the IC memory.

(Problems to be solved) However, the recording time per chip of the IC memory is far shorter than that of a magnetic tape or the like, and for example, a recording time of only about several minutes can be secured.

However, in the conventional recording method to the IC memory, since the writing operation is started and stopped by the manual operation, the starting point of the writing operation is set much earlier than the actual sound generation point. However, there is a problem in that the recording is executed in a silent state, resulting in a large waste of the recording capacity of the IC memory.

Especially when recording the reproduction signal of the magnetic tape in the IC memory, it is difficult to grasp the start and stop points of the writing operation.

By the way, as a control device of a tape recorder, a tape running control device that automatically drives the tape running system when a recording signal of a predetermined level or more is applied and automatically stops the tape running system when the level of the recording signal decreases (for example, Mitsuko Sho 56-4
33) is known, and this device can be applied to an automatic recording system for the IC memory.

However, since the control device starts the recording operation only after the level of the recording signal exceeds the predetermined level, there are the following problems.

For example, when recording a voice that starts with a consonant such as "ku", the pronunciation of the consonant "k" is shorter than that during the pronunciation of the vowel "u", as shown in Fig. 3 (a). Still, the audio level is quite low. Therefore, in order to record the voice of "ku" accurately, the predetermined level is set to be extremely low and the consonant "k" is set.
It is necessary to start automatic recording at the same time as occurrence of. However, this causes a problem of malfunction in that recording is started even with a slight noise sound.

Further, the control device stops the recording operation at the same time when the recording signal drops below a predetermined level. Therefore, for example, the recording is stopped by a slight break between words,
Alternatively, when the pronunciation at the end of a series of voices ends while gradually lowering the level, there is a problem that the last pronunciation part is not reliably recorded and is interrupted.

An object of the present invention is to record all voices including consonants even if the voice starts with a consonant while keeping the reference voice level at which recording should be started at an appropriate value. It is to provide an automatic recording method for a recording medium, which can significantly reduce the number of recordings.

Another object of the present invention is to provide an automatic recording method capable of surely recording even the last sounding portion without omission.

(Means for Solving the Problem) In the recording method of the present invention, in the recording area of the recording medium,
The preliminary recording area and the actual recording area are set. The input audio signal is converted into a digital audio signal, and while the recording is on standby, the digital audio signal is repeatedly written in the preliminary recording area of the recording medium and the level of the input audio signal is continuously detected.

The first level in which the level exceeds a predetermined reference level
At this point, writing of the digital audio signal into the actual recording area of the recording medium is started.

After that, at a second time point when the level of the audio signal falls below a predetermined reference level and the lowered state continues, writing of the digital audio signal to the actual recording area is stopped.

Next, after a time point that is a predetermined time after the first time point,
The first data written in the preliminary recording area up to the time point and the second data written in the actual recorded sound area after the first time point are combined.

(Operation) In the recording standby state, the digital audio signal is always written in the preliminary recording area at a constant cycle. At the first time point when the level of the audio signal exceeds the predetermined level, the digital audio signal for a certain period before the time point is recorded. The audio signal (first data) is recorded in the preliminary recording area.

Therefore, even when recording a voice starting from a consonant, the data representing the consonant is included in the end portion of the first data, and the first data in the preliminary recording area and the second data in the actual recording area are included. By connecting and, it becomes accurate digital audio data including the consonant at the beginning.

During the recording in the actual recording area, the recording operation is stopped when the voice level becomes lower than a predetermined reference level and the state continues (second time point). As a result, a series of voices is recorded without interruption, including the voice part that is finally pronounced.

Next, by combining the first data and the second data, both data are recorded in the recording medium in a state of being connected in time series.

(Effects of the Invention) According to the automatic recording method of the present invention, it is possible to record all voices including consonants, even voices starting with consonants. At this time, since the reference audio level at which recording should be started can be set to an appropriate value, there is no risk of malfunction due to noise or the like.

Further, since the recording is stopped only when the level of the audio signal falls below the predetermined reference level and the state continues, the recording is surely performed up to the last sounding portion of the audio.

Furthermore, since the non-recorded portion caused by the conventional manual operation hardly occurs in the present invention, the recording capacity of the recording medium can be effectively utilized.

(Examples) The examples are for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope.

FIG. 1 shows a circuit configuration for implementing the automatic recording method according to the present invention, and FIGS. 4 (a) to 4 (e) show the state of the recording area in the memory (4).

An input audio signal from a microphone or a tape recorder is connected to the input terminal (1) shown in FIG. 1, and the audio signal is amplified by an amplifier (2) and then digitalized by an A / D converter (3). It is converted into an audio signal. A / D converter (3)
The output of is connected to the data input port of the memory (4).

The memory (4), the recording area for writing the digital audio signal as FIG. 4 (a) (A ₀ address ~Am address in the figure) is provided, the recording area is pre-recorded area (A ₀ Address to Ai)
And the real recording area (addresses (Ai + 1) to Am).

The output terminal of the amplifier (2) is connected to the level detecting circuit (5) as shown in FIG. 1, whereby the level change of the input audio signal is continuously detected.

Both output terminals of the level detection circuit (5) and the reference level setting circuit (6) for setting the reference value of the audio level at the time of starting and stopping the recording are connected to the comparator (7). Compare the magnitude of the output. The comparator (7) outputs a pulse signal indicating that the level of the input audio signal exceeds the reference level during recording standby, and outputs this when the level of the input audio signal falls below the reference level during recording. Is output.

The output pulse of the comparator (7) is the write control circuit (8) that controls the writing operation of the digital audio signal to the memory (4).
To control the start and stop of recording in the actual recording area of the memory (4).

Further, the write control circuit (8) is connected to a time setting circuit (9) for setting predetermined times T ₁ and T ₂ which are information necessary for executing the later-described condensation of recorded data.

Hereinafter, regarding the circuit operation of FIG. 1 and the state change of the recording area in the memory (4) when executing the automatic recording method of the present invention, the flowchart of FIG. 5 and FIGS. Will be described in detail with reference to the explanatory diagram of

When the automatic recording mode is set, the A / D converter in Fig. 1
The digital audio signal output from (3) is supplied to the memory (4), and preliminary recording (FIG. 5 (11)) is executed. That is, the digital audio signal is sequentially written from the address A _{0 to the} address Ai in the preliminary recording area of FIG. 4 (a), and after the writing to the address Ai is finished, the digital audio signal is returned to the address A ₀ again to continue the writing. The operation is repeated at regular intervals.

During this period, an audio signal exceeding a predetermined reference level is generated, and when this is detected by the comparator (7) in FIG. 1 (FIG. 5 (12)), the write control is started from this time (first time). The circuit (8) starts actual recording (Fig. 5 (13)) for the actual recording area of the memory (4). That is, as shown in FIG. 4 (b), the recording address Av in the memory (4) at the first time point is moved to the beginning address (Ai + 1) of the actual recording area, and the digital addresses are sequentially transferred from the recording address. The audio signal is recorded. Further, the write control circuit (8) maintains the built-in timer in the reset state (FIG. 5 (15)) during the actual recording.

After that, at the time when the recording has proceeded to the address Aj in FIG. 4 (b), the level of the audio signal falls below the predetermined reference level,
This is detected by the comparator (7) in Fig. 1 (Fig. 5
(14)), the write control circuit (8) starts measuring the duration of the low level state by the timer and continues the actual recording operation.

In the actual recording after the time when the level of the audio signal is lowered, the signal is recorded from the address (Aj + 1) shown in Fig. 4 (b),
After that, when the timer is set up (FIG. 5 (16)) after a predetermined time has passed with the level being lowered,
At that time (second time), the recording operation is stopped.

As a result, the memory (4) starts from the address (Aj + 1) in FIG. 4 (b).
A silent recording area is formed up to the address Ak. In the silent recording area, in addition to audio signal data below a predetermined reference level,
The silence signal data after the level has dropped to zero will be recorded.

Next, the write control circuit (8) performs the operation of condensing the recording data in the memory (4) (FIG. 5 (17)). That is, the fourth
As shown in Figures (c) and (d), the digital audio signals (Au to Av) recorded up to the first time point after the first time point before the actual recording is traced back by a predetermined time T ₁ are recorded. 1 data) is Al from the (Ai + 1) address, which is the beginning of the actual recording area.
It is moved to the area up to the address (first area). At the same time, the digital audio signal (main data) recorded in the area from (Ai + 1) to Aj in FIG. 4 (c) is transferred from (Al + 1) following the Al. It is moved to the area of Aw address (second area). Further, from the silent recording area in FIG. 4 (c), the sound signal is recorded until a predetermined time T ₂ elapses after it is detected that the audio signal is lower than the predetermined reference level (A
The digital audio signal (end data) from address j + 1 to address Ay follows address Aw in Fig. 4 (d) from address (Aw + 1) to Ax.
Moved to the area up to the address.

The predetermined times T ₁ and T ₂ are the time setting circuit of FIG.
It is possible to set any time by (9).

As a result, the first data, the main data, and the end data are connected in time series, and in the state (Ai in FIG. 4 (d)).
It will be written in the condensed state from address +1) to address Ax.

After the data is condensed, the procedure returns to the preliminary recording (11) in FIG. 5 again, and the recording operation similar to the above is repeated. At this time,
As shown in (e), the same area as described above is used as the preliminary recording area, and a new actual recording area is set with the (Ax + 1) address following the Ax address as the initial address.

Therefore, even when a plurality of audio signals representing different notification contents are intermittently recorded at time intervals, these audio signals are packed and written in the recording area of the memory (4). Is utilized without waste.

According to the above automatic recording method, of course, when recording a voice starting from a vowel "u" as shown in FIG.
Even when recording a voice starting from the consonant "k" as shown in FIG. 3, from the time when the voice level detected by the level detecting circuit exceeds the reference level R by a predetermined period T ₁ from the time τ. Since signals can be recorded in the memory (4), accurate recording including the pronunciation of consonants can be realized.

Also, when recording is stopped, after the audio signal has dropped below the reference level for a specified period of time,
Recording to (4) is stopped and the initial period T of the predetermined time is
_Since only the audio signal recorded in ₂ is finally retained in the memory (4), even if, for example, the sound at the end of a series of voices ends with a gradual decrease in level, the memory ( It is recorded in 4), and in this case, no silent recording part occurs between the recording areas of a plurality of voices.

Further, by adjusting the length of the predetermined time T ₁ and T ₂ by the time setting circuit (9), it is possible to set the minimum required time for various voice waveforms and voice levels by people.
As a result, the memory (4) can be used more effectively.

The drawings and the description of the above embodiments are for explaining the present invention, and limit the invention described in the claims,
Or it should not be understood as reducing the range.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

For example, it goes without saying that the automatic recording system of the present invention can be used not only for recording on an IC memory but also for recording on various recording media such as magnetic disks and optical disks. Further, in the condensation operation, the recording data of FIG. 4 (c) is sequentially shifted to realize the recording state of FIG. 4 (d), but the present invention is not limited to this, and a memory dedicated to the condensation operation is separately provided, It is also possible to temporarily register the data of FIG. 4 (c) in the condensed state in the dedicated memory and then move the contents of the dedicated memory to a predetermined address of FIG. 4 (d).

[Brief description of drawings]

FIG. 1 is a block diagram of an electric circuit for implementing the automatic recording method according to the present invention, and FIGS. 2 (a) and 2 (b) are waveform diagrams of an input voice signal starting with a vowel and a change in its voice level, respectively. Graphs (a) and (b) of FIG. 3 are waveform diagrams of input audio signals starting with consonants and graphs showing changes in their audio levels, respectively.
FIGS. 5A to 5E are views for explaining the recording state in the memory, and FIG. 5 is a flow chart showing the circuit operation of FIG. (1) …… input terminal, (3) …… A / D converter (4) …… memory, (8) …… writing control circuit

Claims (2)

[Claims] 1. A method of writing an audio signal input from the outside to a recording medium, wherein a recording area of the recording medium is set with a preliminary recording area and an actual recording area, and the input audio signal is a digital audio signal. During the recording standby, the digital audio signal is repeatedly written in the preliminary recording area of the recording medium, and the level of the input audio signal is continuously detected, and the level exceeds a predetermined reference level. At the first time point, the digital audio signal is written to the actual recording area of the recording medium, and thereafter, at the second time point when the level of the audio signal falls below a predetermined reference level and the level lowering state continues. After the writing of the audio signal to the actual recording area is stopped, the first data written in the preliminary recording area in the period up to the first time point after the first time point is traced back from the first time point, and after the first time point. Automatic recording system of the recording medium, characterized in that it constitutes a second data written to the real recording region so as to synthesize. 2. The recording medium has a voice signal level lower than a predetermined reference level continuously in a recording region of a digital voice signal from the first time point to a time point when the voice signal level falls below a predetermined reference level. A silent recording area for writing the digital audio signal from the time point to the second time point is provided, and the second data is recorded in the actual recording area in the period from the first time point to the time point when the level of the audio signal falls below a predetermined reference level. The invention according to claim 1, wherein the main data is written and the end data written in the silent recording area within a predetermined time after the time when the level of the audio signal falls below a predetermined reference level. Automatic recording method described.