JPH07307058A - Level control circuit and recording device - Google Patents

Abstract

PURPOSE:To always record signals with an optimum level without adversely affected by the input level of a previous time by temporarily initializing the level control function during a recording medium exchange or a program change while the program is being reproduced. CONSTITUTION:A cassette tape recorder section is provided with a level control circuit 20, a recording/reproducing circuit 21 and a recording head 22. CD reproduced audio signals from a D/A converter 8 are supplied to the circuit 20, processed by the circuit 21 and recorded to a tape TP by a head 22. During a reproducing, the signals read by a head 22 are reproduced and are outputted by a speaker 10 through a switch 23 and an amplifier section 9. A level detecting circuit 20d controls the continuity condition of a transistor Q1 in accordance with the output level of an amplifying circuit 20c. The input signal level is changed by a resistance R1 and ZCE of the transistor Q1. The circuit 20d gives the current which corresponds to the output level of the circuit 20c. Thus, an ALC operation is realized and the output level of an output terminal 20b is suppressed when a large level input is applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a level control circuit known as AGC or ALC and a recording apparatus equipped with the level control circuit.

[0002]

2. Description of the Related Art AGC (Auto Gain Control) and ALC
As (Auto Level Control), a level control circuit that performs automatic gain adjustment and automatic level adjustment for an input signal is known, and is widely used in recording devices such as tape recorders and disk recorders.

By the way, a player portion for a disc-shaped recording medium known as a compact disc (CD) or a mini disc (MD) and a player and a recorder portion for a tape-shaped recording medium such as a compact cassette tape or DAT are integrated. The device provided on the CD is known as, for example, a CD radio-cassette, and the dubbing from the CD to the tape can be easily performed.

A reproducing apparatus has been developed in which a plurality of recording media such as CDs, MDs, compact cassette tapes and DATs are stored in a player equipped with a changer system, and the stored disks or tapes are selectively reproduced. For example, CD changer players have become widespread, and devices (for example, changer CD radio-cassettes) provided with a recording function part such as a tape recorder part and a disk recorder part have been developed.

A device having such a recording function is usually equipped with a level control circuit. For example, when recording a CD reproduction sound on a tape as a recording signal, the recording sound is distorted by a large input level. It is designed so that you will not get chilled.

[0006]

In a changer CD radio-cassette recorder, it is possible to continuously record the reproduced sound from different CDs on a tape.
Since the reproduction level may be greatly different for each CD, especially in such a case, a problem may occur due to the function of the level control circuit.

It is now assumed that a certain CD is reproduced at the CD changer portion and the reproduced sound is supplied to the tape recorder portion for dubbing recording. In this case, the reproduced CD sound is once adjusted in level by the level control circuit and supplied to the recording circuit section.

It is assumed that reproduced sound from a certain CD is supplied as an input to the level control circuit at a level shown as L _{in1 in} FIG. 6 (a). The level control circuit controls the output level by comparing the detection level indicated by the broken line with the input level. For example, if the input level exceeds the detection level at the time point T ₁ , the change in the input level will be as shown in FIG. The output level is set in response as shown in FIG. That is, in this case, the level is suppressed and output is performed. T
_When the performance of the music (program) played on the CD ends at ₂ points and the input level drops, the level control circuit restores the level suppression state to the normal state with a predetermined recovery time that can be set by the CR time constant. Now, input L
Considering only _in1 and ignoring the input L _in2 in FIG. 6 (a), the response to the input after the time point T ₂ is shown in FIG. 6 (b).
become that way.

Here, at the time T ₂ when the reproduction of the input L _in1 is completed, the CD reproduced by the changer system is exchanged, and then the CD is reproduced, and the reproduced sound is reproduced from the time T ₃ as shown in FIG. ) At the level indicated as L _in2 . Since this input L _in2 does not exceed the detection level shown by the broken line, the level should not be suppressed and should be output. However, from the time T ₃
Up to the _4th point, the level control circuit is still input L
_In the recovery period from the response to _{in1, the} input L _in2 is output with its level suppressed from the time point T _{3 to the} time point T ₄ as shown in FIG. 6 (c).
For this reason, it becomes impossible to record at an appropriate level, and the recorded voice becomes uncomfortable in some cases.

[0010] Such a problem is not always reproduced CD
(Or other recording medium such as MD, tape, etc.) does not occur only when it is replaced. For example, in one CD, the level may greatly differ for each program (song, etc.), and may be reproduced. It may also occur when the existing program changes.

[0011]

The present invention has been made in view of the above problems, and an object thereof is to prevent unnecessary level control by the recovery time of the control level of the level control circuit. .

Therefore, as a level control circuit,
Signal generating means for generating a signal in response to a position change of the reproducing side recording medium, and level control means for automatically controlling an output level according to the input audio signal level by inputting a reproduced audio signal from the reproducing side recording medium. , A function control means capable of stopping the function of the level control means based on a signal from the signal generation means. Further, the recording device is provided with a level control circuit having such a configuration so that the recording input signal is controlled.

Here, the signal generating means generates a signal in response to replacement of the recording medium to be reproduced, or in response to a change in the program to be reproduced when reproducing the recording medium in which a plurality of programs are recorded. To do so.

[0014]

With the above structure, the level control function is once cleared and the function is initialized when the recording medium on the reproducing side such as a CD is exchanged or when the program is changed, that is, when the music being reproduced is changed. It becomes a state. That is,
The recovery time from the response of the previous input level is also cleared and the next input level can be properly responded to.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A level control circuit and a recording device according to an embodiment of the present invention will be described below with reference to FIGS. An example of a recording device is a recording / reproducing device in which a 6-series CD changer player and a tape recorder are integrally formed, for example, a recording / reproducing device in the form of a CD radio cassette type. FIG. 3 is a block diagram of a recording / reproducing apparatus equipped with a 6-series CD changer player, in which 1 is a disc changer section and 2 is a reproducing head section. Reference numeral 2a denotes a disc insertion portion, and the tray 2b is pulled out to the disc insertion portion 2a, and the user puts the CD on the tray 2b and stores the tray 2b, so that the disc D is loaded into the reproducing head portion 2. It

The disc thus conveyed inside the apparatus by the tray 2b is reproduced by the reproducing head unit 2 or conveyed to the accommodating unit 1a of the disc changer unit 1 according to a user's operation. . Reference numeral 2c denotes a sensor, which can detect whether or not the disc D is placed on the tray 2b.

The storage unit 1a can store six discs D, and the discs are managed by disc numbers such as disc 1 to disc 6 depending on the storage position. In the disc changer unit 1, the storage unit 1a is moved up and down in the UD direction in the figure by the lifting motor 1b,
The disc to be moved (loading and unloading) between the reproducing head unit 2 and the reproducing head unit 2 is selected. Storage 1a
The disc selected at the ascending / descending position is moved between the reproducing head units 2 by the loading mechanism 1d driven by the loading motor 1c.

The user can reproduce the disc D inserted from the disc insertion portion 2a or the disc D loaded from the storage portion 1a by the reproduction head portion 2. Reference numeral 3 denotes a spindle motor, 4 denotes an optical head, and the disk D loaded in the reproducing head unit 2 is driven to rotate by CLV by the spindle motor 3 and
The recording data is read by the laser irradiation from the optical head 4.

That is, the laser light emitted from the laser diode in the optical head 4 passes through an optical system such as a diffraction grating, a beam splitter, and a quarter wave plate, and is emitted from the objective lens onto the disk recording surface. Then, the reflected light is extracted from the above optical system by a beam splitter, irradiated onto a detector through a cylindrical lens or the like, and converted into an electric signal.

An RF calculator 5 is supplied with the signal extracted by the detector of the optical head 4 and generates an RF signal as reproduction data, a focus error signal EF, and a tracking error signal ET by calculation processing.
Focus error signal EF, tracking error signal E
T is supplied to the servo circuit 7 and applied as a focus drive signal FD and a tracking drive signal TD to the biaxial mechanism that supports the objective lens of the optical head 4. A sled drive signal SD is also generated based on the tracking error signal ET and is supplied to a sled mechanism that drives the optical head 4 in the disk radial direction.

The RF signal output from the RF calculation unit 5 is supplied to the decoder 6 and subjected to EFM demodulation, CIRC error correction processing and the like. Then, it is converted into analog audio signals (L, R) by the D / A converter 8 and output as audio from the speaker 10 via the T _CD terminal of the switch 23 and the amplifier 9.

In the decoder 6, the subcode data C
Clock error signal E _SP for _SUB and spindle servo
Are taken out and supplied to the control unit 11. Control unit 1
_{Reference numeral} 1 denotes a microcomputer, which controls each unit according to a user's operation or sub code data C _SUB . Further, the spindle servo signal SS is supplied to the servo circuit 7, the spindle drive signal SPD is applied to the spindle motor 3, and the servo circuit 7 is controlled by the track jump signal (jump pulse) TJ to execute the access operation of the optical head 4. Let

Reference numeral 12 denotes an operation section provided with various operation keys provided on an outer casing panel of the apparatus, such as operation keys for storing / removing a disk to / from the disk changer section 1, reproduction, stop, fast forward, fast rewind, AMS, etc. Reproduction mode operation keys such as CD operation keys, shuffle reproduction, and program reproduction are provided, and operation keys for reproduction, recording, stop, fast forward, rewind, etc. for the cassette tape recorder are provided. 13 is a display unit. Display 1
In 3, the time information of the CD being reproduced, the operating state of the cassette tape recorder, various mode states, etc. are displayed under the control of the controller 11.

As the cassette tape recorder, a level control circuit 20, a recording / reproducing circuit 21, and a recording / reproducing head 22 are provided. The level control circuit 20 outputs from the D / A converter 8, that is, a CD reproducing audio signal. The recording / reproducing circuit 21 processes the recording signal through the level control circuit 20, and the recording / reproducing head 22 can record the CD reproduction audio signal on the magnetic tape TP. There is. Further, during tape reproduction, the signal read from the recording / reproducing head 22 is subjected to reproduction signal processing by the recording / reproducing circuit 21, and is supplied from the T _T terminal of the switch 23 to the amplifying unit 9 and the speaker 10
Is output as audio from.

In such a recording / reproducing apparatus, the user can perform the recording operation on the cassette tape recorder and the CD reproducing operation to dub the reproduced music from the CD onto the tape. And
Especially, since a plurality of CDs are stored in the disc changer unit 1, in addition to dubbing from one CD, a plurality of Cs
Select the song order program over D and record it on tape, or shuffle the one or more CDs, and play the songs that are played in random order on the tape. Various dubbing, such as dubbing, can be performed.

At the time of these dubbing recordings, the CD reproduced sound is supplied to the level control circuit 20 as described above, and the level control circuit 20 is constructed as shown in FIG. 20a is an input terminal, 20
Reference numeral b is an output terminal, 20c is an amplifier circuit, and 20d is a level detection circuit. The level detection circuit 20d detects the output level of the amplification circuit 20c, and accordingly applies a current to the base of the transistor Q ₁ . Therefore, the transistor Q
The conduction state of ₁ is controlled according to the output level of the amplifier circuit 20c.

Here, the input signal level is changed by the resistance between the resistor R ₁ and the collector-emitter of the transistor Q ₁ . That is, as the transistor Q ₁ becomes conductive and the collector-emitter impedance becomes lower, the level of the input signal is attenuated and output, and therefore the level detection circuit 20d.
Supplies a rectified current according to the output level of the amplifier circuit 20c to the transistor Q ₁ , so that the so-called ALC operation is realized so that the output level of the output terminal 20b is suppressed when a large level is input.

The resistor R ₂ and the capacitor C _{1 form} a so-called time constant circuit, and the resistor R ₂ and the capacitor C ₁ determine the recovery time of the ALC level (holding level) and ON / OFF of the ALC function. The circuit configuration up to this point is similar to that of a so-called normal ALC circuit, but in the case of this embodiment, a transistor Q ₂ is further connected,
By turning on the transistor Q ₂ , the capacitor C
It is designed to be able to discharge ₁ .

A control signal S _C is supplied from the control unit 11 to the base of the transistor Q ₂ via the resistor R ₃ to control the on / off of the transistor Q ₂ . Then, by turning on the transistor Q ₂ and discharging the capacitor C ₁ , the recovery time as the ALC circuit is cleared and the ALC function is reset to the initial state.

Therefore, the level control circuit can properly respond even if, for example, CDs or programs having different reproduction levels are continuously reproduced and input. This will be described with reference to FIG.

Now, from the disc changer unit 1 to a certain C
It is assumed that D is loaded into the reproducing head unit 2 and reproduced, and the reproduced sound is supplied to the tape recorder unit for dubbing recording. At this time, it is assumed that the level control circuit 20 is supplied with an input level of L _{in1 in} FIG. The level control circuit 20 compares the detection level indicated by the broken line with the input level to perform the output level control. For example, if the input level exceeds the detection level at the time point T ₁₁ , the change of the input level is shown in FIG. The output level is set in response as shown in 2 (c). That is, in this case, the level is suppressed and output is performed.

At time T ₁₂ , since the performance of the music (program) played on the CD is completed and the input level is lowered, the level control circuit normally maintains the level suppression state with the predetermined recovery time by the capacitor C ₁ and the resistor R _2. The state will be recovered, but in this embodiment, as shown in FIG.
(B) the control signal S _C from the control unit 11, for example, T ₁₃ point as shown in the transistor Q ₂ is applied to the transistor Q ₂ is turned. Therefore, the capacitor C ₁ is discharged and the ALC function is reset. That is, considering only the input L _in1 , the input L in FIG.
_{When in2} is ignored, the response to the input after the time point T ₁₂ is as shown in FIG. 2 (c).

Here, at the time T ₁₂ when the reproduction of the input L _in1 is completed, the CD is exchanged by the operation of the disc changer unit 1, and then the exchanged CD is reproduced by the reproducing head unit 2, and T ₁₄ From the point in time, the reproduced sound is L _{in2 in} FIG.
It is assumed that it is supplied at the level shown as. At this time A
Since the LC function has been reset to the initial state, input L
_It is possible to properly respond to _{in2 as} shown in FIG. That is, the influence of the recovery period of the response to the input L _in1 as in the conventional case appears in the input L _in2 .

That is, in the present embodiment, the control unit 11 turns off the ALC function at a predetermined timing, so that A
The inconvenience caused by the influence of the LC recovery time is eliminated. This A
In order to effectively perform the LC function reset operation, the control unit 1
1 indicates the control signal S by the processing as shown in FIG. 4 or FIG.
_C should be generated.

FIG. 4 shows a process of resetting the ALC function when the CD is exchanged. That is, (F
100), and a CD exchange request is made (F101). When there is a CD exchange request, for example, when the user performs an operation to select another CD in the disc changer unit 1, or when a program reproduction or shuffle reproduction is performed, a song (program) of another CD is selected as the next song. This is the case when the CD reproduced by the reproducing head unit 2 is exchanged with the end of the performance of the current music.

When such a CD exchange request is made, first, C which has been reproduced and played by the reproducing head unit 2 until now.
Stop D (F102). Then, at this time, it is determined whether or not the recording operation is being executed in the tape recorder unit (F103). Then, when the tape recorder is in the recording operation, the control signal S _C is output to turn off the ALC function as described above (F104). If recording is not in progress, the level control circuit 20 is not functioning and nothing is done.

Then, the disc changer unit 1 is caused to perform a CD exchange operation (F105), and when the exchange is completed (F10
6) When the tape recorder is recording, the output of the control signal S _C is stopped and the ALC function is turned on (F
107, F108). Then, the reproduction head unit 2 starts reproduction of the CD (F109).

That is, the control unit 11 temporarily turns off the ALC function each time the CD to be reproduced is exchanged during the recording operation of the tape recorder unit, so that the reproduction level of each CD is considerably increased. Even if they are different, the level control circuit 20 can properly perform the ALC operation from the start of reproduction of each CD.
Therefore, it is possible to always record on the magnetic tape TP at a suitable recording level.

Further, FIG. 5 shows a process for resetting the ALC function when the track being accessed is performed on the CD being reproduced even if the CD is not exchanged.
That is, it is assumed that a request to move to the next program (song, track) is made during the CD performance (F200) (F201).
The case where there is a movement request is, for example, when the user performs an AMS (cue) operation or direct track number input, or when performing track access as the next tune in program reproduction or shuffle reproduction.

When such a movement request is made, a mute process is normally performed so that unnecessary voice output is not made during access (F202). Then, at this time, it is determined whether or not the recording operation is being performed in the tape recorder unit (F203). Then, when the tape recorder is in the recording operation, the control signal S _C is output and the ALC function is turned off as described above (F204). If recording is not in progress, the level control circuit 20 is not functioning and nothing is done.

Then, the servo circuit 7 is controlled to cause the reproducing head unit 2 to execute the access operation. That is, first, a track jump is executed so that the track number obtained as subcode data from the CD becomes the target track number (F205, F206), and then the start time of the target track (the elapsed time of the subcode in the song is 00). Access to the position (minute 00 second) (F207, F208, F209). Finally, access is made at the frame level (position where the frame number in the music of the sub chord is 00) (F210, F211, F212), and the access operation is ended.

After the access is completed, if the tape recorder is in the recording operation, the output of the control signal S _C is stopped and the ALC function is turned on (F213, F214). And
The mute is released (F215), and the reproduction head unit 2 starts reproduction of the CD (F216).

As described above, the control unit 11 temporarily turns off the ALC function each time an access operation is performed on the CD to be reproduced during the recording operation of the tape recorder unit. Even if there are music (programs) that are considerably different from each other, the level control circuit 20 appropriately responds from the start point of reproduction of each music.
The LC operation can be performed, and therefore, also in this case, it is possible to always record on the magnetic tape TP at a suitable recording level.

Further, as another example of processing, the control unit resets the ALC function once at the time when the music changes even during the normal reproduction in which the first music is reproduced from the first music in order of the track number. Good. That is, by checking the P-channel data of the subcode that becomes "1" between songs, or by checking the index code that becomes "00" between songs on the Q channel of subcode. , The timing to move to the next song can be detected, and at this time, the level control circuit 20 can reset the ALC function by giving the control signal S _C for a predetermined time.
Alternatively, when muting is performed in the period between songs, the period control signal S _C may be output and reset using a signal for obtaining the mute on timing and the mute release timing.

Although the above embodiment has been described as a recording / reproducing apparatus having a CD changer section and a tape recorder section, the present invention can be applied to various devices other than this. For example, the reproduction part may be an ordinary CD player (without a changer function), an MD player, a tape player such as a DAT or a compact cassette tape, or an MD changer or a tape changer. Further, the recording portion may be a disc recorder such as an MD recorder in addition to the tape recorder. A configuration in which such a level control circuit is arranged in the reproducing circuit system is also conceivable. Further, the present invention can be applied to the case where the reproduction part and the recording part are separate bodies. For example, when the CD changer and the cassette tape recorder are separate units, the level control circuit mounted in the recording device, that is, the cassette tape recorder is configured so that the control signal S _C is supplied from the CD changer side. It suffices that the cable or the like for supplying the control signal S _C is connected between the devices.

[0046]

As described above, according to the present invention, for example, when the recording medium on the reproducing side such as a CD is exchanged or when the program is changed, that is, when the music being reproduced is changed,
Since the level control function is once cleared and the function returns to the initial state, there is an effect that an appropriate level adjustment operation is performed without being affected by the input level of the previous time with respect to a new input, which is always suitable. There is an effect that recording can be performed at various levels.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a level control circuit according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of the level control circuit according to the embodiment.

FIG. 3 is a block diagram of an embodiment.

FIG. 4 is a flowchart of a function reset control of the level control circuit according to the embodiment.

FIG. 5 is a flowchart of a function reset control of the level control circuit according to the embodiment.

FIG. 6 is an explanatory diagram of an operation of a conventional level control circuit.

[Explanation of symbols]

1 Changer Section 2 Playback Head Section 3 Spindle Motor 4 Optical Head 5 RF Calculation Section 6 Decoder 7 Servo Circuit 11 Control Section 12 Operation Section 13 Display Section 20 Level Control Circuit 20c Amplification Circuit 20d Level Detection Circuit 21 Recording / Playback Circuit 22 Recording / Reproduction head 23 switches Q _1, Q ₂ transistor C ₁ capacitor R _1, R _2, R ₃ resistors

Claims (6)

[Claims] 1. A signal generating means for generating a signal according to a position change of a reproducing side recording medium, and a reproduced audio signal from the reproducing side recording medium are inputted, and an output level is automatically adjusted in accordance with the input audio signal level. A level control circuit comprising: a level control unit for controlling; and a function control unit capable of stopping the function of the level control unit based on a signal from the signal generating unit. . 2. The level control circuit according to claim 1, wherein the signal generating means generates a signal in response to replacement of a recording medium to be reproduced. 3. The signal generating means, when reproducing a recording medium on which a plurality of programs are recorded, generates a signal according to a change in a program to be reproduced. Level control circuit. 4. A signal generating means for generating a signal according to a position change of a reproducing side recording medium, and a reproduced audio signal from said reproducing side recording medium are inputted, and an output level is automatically adjusted according to the input audio signal level. A level control circuit that controls and supplies the recording means with a level control means; and a function control means that can stop the function of the level control means based on a signal from the signal generating means. A recording device characterized by being performed. 5. The recording apparatus according to claim 4, wherein the signal generating means generates a signal in response to replacement of a recording medium to be reproduced. 6. The signal generating means according to claim 4, wherein when reproducing a recording medium having a plurality of programs recorded therein, the signal generating means generates a signal in accordance with a change of the program to be reproduced. Recording device.