JPH02230554A - Audio signal sound recorder and reproducer - Google Patents

Abstract

PURPOSE:To bring a regenerative level back to an exactly original audio signal sound level by recording a recording level manually adjusted at the time of recording as an incidental information to an audio signal to a recording medium and adjusting a regenerative output level in accordance with a difference between the recording level shown by this incidental information read out at the time of reading and a reference level. CONSTITUTION:At the time of recording, and audio signal is adjusted by a manual recording level adjusting means 2 to a recording level, and recorded in its digital signal to a recording medium, and at the time of reproducing, the digital signal is read out of the recording medium and reproduced to be as an audio signal, thus constituting the subject device. Then, the device is provided with a means 3 for detecting the recording level set by the recording level adjusting means 2, recording means 4-12 for recording at any time the recording medium with the recording level as the incidental information to the audio signal at the time of recording, a read means 10 for reading the incidental information from the recording medium at the time of reproducing and reproduction level adjusting means 11 and 13-19 for adjusting the reproduction output level in accordance with a difference between the recording level shown by the read incidental information and the reference level. By this method, the reproduction level can be restored to the original audio signal sound level following exactly its change.

Description

TECHNICAL FIELD The present invention relates to an audio signal recording/playback device such as a digital audio tape recorder.

BACKGROUND ART In an audio signal recording and reproducing apparatus, during recording of an audio signal onto a recording medium, a recording level adjusting means such as a volume may be manually operated to change the level to an appropriate level. However, if the recording level adjustment means is operated during recording in this way, the level of the audio signal obtained by playing back from the recording medium will fluctuate midway through, and the volume change will not match the original audio signal. This creates the inconvenience of having to adjust the volume level.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide an audio signal recording and reproducing apparatus that can reproduce the original audio signal according to the change in volume level even when a recording level adjustment means is operated during recording.

The audio signal recording/playback device of the present invention adjusts an audio signal to a recording level determined by a manual recording level adjustment means during recording, records the signal as a digital signal on a recording medium, and reads the digital signal from the recording medium during playback. This is an audio signal recording and playback device that plays back an audio signal, and features a means for detecting a recording level using a recording level adjustment means, and a recording system that records the recording level as incidental information of the audio signal on a recording medium at any time during recording. A reading means for reading accompanying information from a recording medium during reproduction, and a reproduction level adjusting means for adjusting a reproduction output level according to a difference between a recording level indicated by the read accompanying information and a reference level.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a digital audio tape recorder as an audio signal recording and reproducing apparatus according to the present invention.

In the recording system of this tape recorder, two-channel input audio signals are first supplied to a variable resistor 2 via a buffer amplifier 1 and attenuated. Variable resistor 2
As shown in FIG. 2, the rotating shaft 2a has an operating knob 2b for manual operation. Further, a rotary encoder 3 consisting of a potentiometer is provided on the rotating shaft 2a. The low rotation encoder 3 generates a voltage according to the rotation angle of the rotary shaft 2a with characteristics as shown in FIG. Note that the rotary encoder 3 may be one that optically generates an output according to the rotation angle of the rotating shaft 2a. The output voltage of the low-resolution encoder 3 is supplied to the control circuit via the A/D converter 23. 1. LPF4 is connected to the output of variable resistor 2, and LPF4 is connected to the output of variable resistor 2.
An A/D converter 5 that performs A/D conversion according to a timing signal from the control circuit 11 is connected to the output of the PF 4 . Audio signal information converted into a digital signal by the A/D converter 5 is supplied to an encoder 6. The encoder 6 adds redundant parity for error correction, and also performs processing such as interleaving for distributing data and formatting for data compression. A RAM 7 is connected to the encoder 6 for this processing. The audio signal output from the encoder 6 is 8-10 modulated by the modulator 8 and then supplied to the recording amplifier 9.

The output signal of the recording amplifier 9 is supplied to a rotary head 10 via a rotary transformer (not shown) and recorded on a tape.

In addition, the recording amplifier 9 has a tracking ATF (
An automatic track finding (TrackFinding) signal generation circuit 12 is connected, and the ATF signals are time-division multiplexed so that recording is performed in a predetermined track area. Subcode data is generated by a control circuit 11 and formatted by an encoder 6.

Next, in the reproduction system, the signal read from the tape by the rotary head 10 is supplied to a reproduction amplifier 13 via a rotary transformer. The reproducing amplifier 13 amplifies the signal, then improves the frequency characteristics using a waveform equalizer (not shown), and then extracts the data as a digital signal using a signal detector (not shown). The extracted data is supplied to the demodulator 14 and is subjected to 8-10 demodulation. Demodulator 1
The output signal of 4 is supplied to a decoder 15. Decode 1
In step 5, in addition to error correction processing, deinterleaving is performed to rearrange the data to its original order, and processing is performed to restore data that has been time-axis compressed to its original state, convert it into continuous data, and output it. For these processes, the decoder 15 also serves as the recording system RAM 7. The output data of the decoder 15 is supplied to the D/A converter 16 and converted into an analog audio signal, and then outputted via the LPF 17 and the output amplifier 18 . The output amplifier 18 is a voltage controlled amplifier and has an input terminal for gain control. A D/A converter 19 is connected to this input terminal, and the D/A converter 19 supplies a voltage according to a control signal from the control circuit 11 to an input terminal for gain control of the output amplifier 18.

The servo circuit 20 includes a drum servo, a capstan servo,
Performs servo control such as reel servo.

The control circuit 11 is composed of a microcomputer, and performs processing such as controlling mechanisms such as a tape drive mechanism (not shown), interfacing with the keyboard 21, driving the display device 22, and subcode processing to be described later.

Note that switching between recording and reproduction is performed by a switch 24 in accordance with a command from the control circuit 11.

In the audio signal recording and reproducing apparatus according to the present invention, if the recording level setting switch (not shown) of the keyboard 21 is on during recording, the operating position of the variable resistor 2 is written on the tape as a subcode. That is, the recording level setting switch is a switch that is turned on only during the period when the recording level is set by operating the variable resistor 2 during recording, and the processor in the control circuit 11 turns on the recording level setting switch according to the turning on of the recording level setting switch. As shown in FIG. 4, recording level data corresponding to the output voltage of the rotary encoder 3 is immediately created as a subcode and output to the encoder 6 (step 31). As a result, the encoder 6 formalizes the data as a subcode (ancillary information) of the audio signal information at that time, and the data is supplied to the rotary head 10 via the modulator 8 and recording amplifier 9 and recorded on the tape. It is written in the subcode area that is formed. Next, it is determined whether the recording level setting switch is on or not (step 32). If the recording level setting switch is on, the process returns to step 31 and the recording level data corresponding to the output voltage of the rotary encoder 3 is subcoded. and output it to the encoder 6. If the recording level setting switch is off, a recording level adjustment end command has been generated, and data including the reference level flag and the above recording level data to indicate that the recording level has been finally set is created as a subcode, and the encoder 6
(Step 33). This allows encoder 6
In this step, data including a reference level flag and recording level data is formatted as a subcode of audio signal information at the time when the recording level is finally set. Therefore, a subcode area containing the data is formed on the tape.

When the processor of the control circuit 11 receives a reproduction operation mode command from the keyboard 21, as shown in FIG. Determine (step 41),
If the automatic playback volume control switch is off, normal playback mode control is performed (step 42). On the other hand, if the automatic playback volume control switch is on, a high speed search drive command is generated (step 43). The tape is driven at high speed by the servo circuit 20 in response to this high speed search drive command. At this time, subcodes are sequentially extracted from the decoder 15 and supplied to the control circuit 11. Therefore, next, it is determined whether the content of the subcode is a reference level flag (step 44). When the reference level flag is detected, the recording level data included in the subcode in which the reference level flag was detected is read and written to the RAM (not shown) in the control circuit 11 as reference level data (step 45), and the playback operation mode is started. A high speed reverse drive command is generated to return to the tape playback start position where the command was generated (step 46). Next, it is determined whether the tape reproduction start position has been reached (step 47). Determination as to whether the tape playback start position has been reached is carried out, for example, by placing a subcode on the tape in blue, which indicates the position at which the automatic playback volume control switch is turned on, as a flag, and detecting it. When the tape playback start position is reached, the playback mode is controlled (step 48) and the recording level data of the subcode obtained from the decoder 15 is read (step 49).
A control signal corresponding to the difference between the reference level data stored in M and the read recording level data is output to the D/A converter 19 (step 50). Then decoder 1
It is determined whether the reference level flag is detected from the subcode from 5 (step 51). If the reference level flag is not detected, the process returns to step 49, and if the reference level flag is detected, this routine is ended and playback mode control is continued.

If the recording level data read in step 49 is lower than the reference level data, the control signal indicates to increase the playback level by an amount corresponding to the difference, and therefore, the gain of the output amplifier 18 is adjusted according to this control signal. Rise.

On the other hand, if the read recording level data is higher than the reference level data, the control signal indicates that the playback level should be lowered by an amount corresponding to the difference, and therefore the gain of the output amplifier 18 is adjusted according to this control signal. descend.

Therefore, the audio signal output from the output amplifier 18 becomes a signal that corresponds to the original volume level change.

If the reference level flag is not detected in step 44 and this state continues for more than a predetermined time (step 52),
Alternatively, when the end of the tape has been reached (step 53), it is assumed that there is no need to adjust the automatic playback level, and a high-speed reverse drive command is issued (step 54), and it is determined whether the tape playback start position has been reached. (Step 55), and if it has been reached, normal playback mode control is performed (Switch 42).

In the above embodiment, a voltage control amplifier is used as the output amplifier 18 to adjust the playback level, but a variable resistor is provided at a stage subsequent to the D/A converter 16, and the variable resistor is connected to the control circuit. It may be driven by a motor according to a control signal from 11. The playback level is not limited to being adjusted at the analog level, but may be adjusted at the digital signal stage after the D/A converter 16.

In addition, in the embodiment described above, steps 44 and 52
．． As a result of executing step 53, if the reference level flag is not detected, the control returns to the tape playback start position and enters playback mode control, but the present invention is not limited to this, and for example, a shift may be made to a stop mode in which the operation is stopped.

Furthermore, the present invention is applicable not only to digital audio tape recorders but also to digital audio disc recording and reproducing apparatuses capable of recording and reproducing.

Effects of the Invention As described above, in the audio signal recording and reproducing apparatus of the present invention, the recording level manually adjusted during recording is recorded on the recording medium as accompanying information of the audio signal, and the accompanying information is read from the recording medium during playback. The playback output level is adjusted according to the difference between the recording level indicated by the accompanying information and the reference level, so even if the recording level is changed during recording until the final setting, the playback level will remain the same as the volume level of the original audio signal. You can make changes.

The present invention is particularly effective in cases where the recording level cannot be determined immediately, such as in live recording.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the variable resistor and rotary encoder in the device shown in FIG. 1, FIG. 3 is a diagram showing the characteristics of the rotary encoder, and FIG. 4 and 5 are flow diagrams showing the operation of the control circuit in the apparatus of FIG. 1. Explanation of symbols of main parts 2...Variable resistor, 3...Lower encoder, 6
... Encoder, 10... Rotating head, 11...
Control circuit, 15...Decoder applicant Pioneer Corporation

Claims (3)

[Claims] (1) An audio signal that adjusts the audio signal to a recording level determined by a manual recording level adjustment means during recording, records it on a recording medium as a digital signal, and reads the digital signal from the recording medium during playback and reproduces it as an audio signal. The recording/playback apparatus includes means for detecting a recording level by the recording level adjustment means, a recording means for recording the recording level as incidental information of an audio signal on a recording medium at any time during recording, and a recording means for detecting the recording level from the recording medium during playback. An audio signal recording and reproducing device comprising: a reading means for reading information; and a reproduction level adjusting means for adjusting a reproduction output level according to a difference between a recording level indicated by the read accompanying information and a reference level. (2) The recording means records the recording level at that time and a flag indicating the end of the recording level adjustment as the accompanying information in response to the recording level adjustment end command, and the playback level adjusting means records the accompanying information read by the reading means. 2. The audio signal recording and reproducing apparatus according to claim 1, wherein the recording level when the flag is included in the recording level is set as the reference level. (3) The audio signal recording and reproducing apparatus according to claim 1 or 2, wherein the reading means first reads the accompanying information including the flag from a recording medium during reproduction.