JP2964510B2 - Magnetic recording / reproducing device - Google Patents

Description

The present invention relates to a magnetic recording / reproducing apparatus, and can be applied to, for example, a digital audio tape recorder for recording / reproducing a digital audio signal.

The present invention relates to a magnetic recording / reproducing apparatus, which detects a subcode area using a self-propelled counter circuit synchronized with a synchronization signal for ATF tracking control, thereby reliably detecting the subcode area. You can dub.

C Prior Art Conventionally, a magnetic recording / reproducing apparatus (hereinafter referred to as a digital audio tape recorder) for recording / reproducing a digital audio signal using a rotating drum is capable of dubbing subcode data.

That is, in the digital audio tape recorder, the magnetic tape is reproduced under the ATF (automatic track finding) tracking control.

At this time, the sub-code area is detected based on the synchronization signal for ATF tracking control, and based on the detection result, during the period in which the magnetic head scans the sub-code area,
The mode switches from the playback mode to the recording mode.

On the other hand, if the synchronization signal for ATF tracking control cannot be detected due to dropout, the subcode area is detected based on the output signal of the position detection sensor attached to the rotating drum.

Thus, in the digital audio tape recorder, only the subcode data in the subcode area is recorded again, and the subcode data can be dubbed.

D Problems to be Solved by the Invention Incidentally, in the position detection sensor, since the mounting error cannot be avoided, the detection accuracy of the subcode area is reduced accordingly.

Therefore, conventionally, in a digital audio tape recorder, an output signal of a position detection sensor is delayed by using a delay circuit capable of adjusting a delay time, thereby correcting a mounting error of the position detection sensor. In this case, a subcode area is detected.

Therefore, in order to detect the sub-code area with high accuracy based on the output signal of the position detection sensor as in the case of using the synchronization signal for ATF tracking control as a reference, the adjustment accuracy of the delay time must be adjusted accordingly. The sub-code data cannot be reliably dubbed if the adjustment accuracy is low.

The present invention has been made in view of the above points, and intends to propose a magnetic recording / reproducing apparatus that can reliably detect a subcode area and perform post-recording even when a synchronization signal for ATF tracking control cannot be detected. Things.

Means for Solving the Problem In order to solve the problem, the present invention relates to a rotating drum 2 provided with magnetic heads 20A and 20B around which a magnetic tape 10 is wound at a predetermined winding angle, and a magnetic head 20.
Repeating A, from the reproduced signal S _RF reproduced from the magnetic tape 10 at 20B, the detecting means 26 for detecting a synchronization signal for ATF tracking control, magnetic head 20A, the synchronization with sequentially counting the scanning cycle 20B Counting means 28 and the counting means
Control signal generating means 30 for generating a control signal _DMD indicating a period during which the magnetic heads 20A and 20B scan the subcode area on the magnetic tape 10 based on the count value _{DCNT of} 28, and the control signal generating means 30 Mode switching means 30 for switching the recording / playback mode based on the control signal _DMD generated in
If, when the synchronization signal for ATF tracking control by detecting means 26 has failed is detected based on the count value D _CNT at the time of the previously detected, for after-recording to rewrite only the sub-code area on the magnetic tape 10 And an output unit 34 for outputting the recording signal S _REC .

F action As a result, even if the synchronization signal for ATF tracking control cannot be detected due to the dropout, the count value DCNT of the counting means 28 which repeats the count operation in synchronization with the scanning cycle of the magnetic heads 20A and 20B is added to the count value _DCNT . By switching the recording / reproducing mode based on this, the subcode area can be detected with high accuracy and dubbing can be reliably performed.

G Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a digital audio tape recorder as a whole, which dubbs recording data D _REC .

That is, in the digital audio tape recorder 1, the rotating drum 2 winds the magnetic tape 10 obliquely at a winding angle of 90 degrees using the guide rollers 4 to 7 and the inclined guides 8 and 9, and rotates at a predetermined speed.

At this time, the capstan 12 is driven by the capstan motor 14 to cause the magnetic tape 10 to run at a predetermined speed together with the pinch roller 16, thereby scanning the magnetic tape 10 with the magnetic heads 20A and 20B mounted on the rotating drum 2. The trajectories are sequentially formed diagonally.

Further, as shown in FIG. 2, the digital audio tape recorder 1 comprises output signals FG and PG of a speed detection sensor and a head position detection sensor attached to the rotating drum 2.
Is supplied to the switching pulse signal generation circuit 22, and the signal level switches at the timing of starting the scanning of the magnetic heads 20A and 20B (FIG. 2 (A)).
Generate

Regenerative amplification circuit 24, the control signal D _MD switching operation based on, thereby the magnetic head 20A and 20B during the period of scanning the area other than the sub-code area, the magnetic head 20A and a reproduction signal S output from the 20B _{While the RF} (FIG. 2B) is amplified and output, the operation is stopped during the period when the magnetic heads 20A and 20B scan the subcode area.

The synchronization signal detection circuit 26 detects a synchronization signal for ATF tracking control from the output signal of the reproduction amplification circuit 24, and an ATF detection signal ATSY (FIG. 2 (C)) whose signal level rises at the timing when the synchronization signal is input. ) Is output.

The counter circuit 28 sequentially counts a predetermined clock signal CK and outputs a count value D _CNT (FIG. 2 (D)) to the decoder circuit 30, so that when the count value D _CNT reaches a predetermined value, the decoder circuit 30 Reset signal output from
The counter is reset by CTRST (FIG. 2 (E)) and the counting operation is repeated again. Thereby, the counting is sequentially performed at a half cycle of the switching pulse signal SWP (that is, a scanning cycle of the magnetic heads 20A and 20B). The operation is repeated.

Further counter circuit 28, the signal level of the ATF detection signal ATSY rises, loading a predetermined setting data D _SET (shown in broken lines in FIG. 2), counts the clock signal CK from the set data D _SET.

That is, the area where the synchronization signal is recorded is designated as A head 20A.
At the time t1 but the scanning, to load the configuration data D _SET value L1, at the time t2 for scanning the area where the remaining synchronizing signals are recorded A head 20A, set the value L2 data D _SET To load.

Similarly, at time t3 when the B head 20B scans the area where the synchronization signal is recorded, the setting data _DSET having the value L3 is loaded, while the B head 20B scans the remaining area where the synchronization signal is recorded. at the time t4 to scan, loading configuration data D _sET value L4.

As a result, in the counter circuit 28, the digital audio tape recorder 1 is switched from the reproduction mode to the after-recording mode. For example, even if it is not possible to detect the synchronization signal for ATF tracking control due to dropout at time t41, the previous time t3 Setting data D
Repeats the count operation based on _SET , magnetic head 20A
And the counting operation can be repeated in synchronization with the scanning of 20B.

The decoder circuit 30 outputs the reset signal CTRST, the count value D _CNT outputs the control signal D _MD whose signal level rises enters the predetermined set range, thereby the magnetic head 20A and 20B scans the subcode area during the interval, it raises the signal level of the control signal D _MD.

The recording signal generation circuit 34 performs recording data D _{REC to be} post-recorded.
A recording signal S _REC is converted into (FIG. 2 (G)), the through the recording amplifier circuit 38 the recording signal S _REC magnetic head 20A and 20B
Output to

In this case the recording signal generation circuit 34, AB head 20A based on the scan Germany quenching pulse signal SWP, together with identifying 20B generates a recording signal S _REC, during the period in which the signal level of the control signal D _MD rises, the Outputs the recording signal S _REC .

Thus, even when the synchronization signal for ATF tracking control cannot be detected due to the dropout, the recording signal S _REC for dubbing based on the count value of the counter circuit 28 that repeats the count operation in synchronization with the scanning of the magnetic heads 20A and 20B. By outputting the recording signal S _REC by detecting the sub-code area with remarkably higher accuracy than when the position detection sensor is used, whereby the post-recording can be reliably performed. .

Thus the counter circuit 28 and the decoder circuit 30 repeats the counting operation of the predetermined clock signal CK in the scanning period of the magnetic head 20A and 20B, loading a predetermined configuration data D _SET on the basis of the detection result CATSY the synchronization signal detection circuit 26 and while constituting a counter circuit of the self-propelled repeating the counting operation, the decoder circuit 30, based on the count result D _CNT of the counter circuit 28, a mode switching circuit for outputting a switching signal D _MD recording and reproducing modes Is configured.

In the above configuration, the counter circuit 28 outputs the clock signal
Sequentially counts the CK, reset signal CTRST which the count value D _CNT is output from the decoder circuit 30 when a predetermined value
The counting operation is repeated in the scanning cycle of the magnetic heads 20A and 20B.

At this time, the counter circuit 28 turns on the magnetic heads 20A and 20B.
At the timing of scanning the synchronizing signal recording area for ATF tracking control, loading a predetermined setting data D _SET, thereby counting operation is performed in synchronization with timing of scanning of the magnetic head 20A and 20B.

Thus by determining the count value D _CNT of the counter circuit 28 in the decoder circuit 30, the period which the magnetic head 20A and 20B scans the subcode area, it is possible to obtain a control signal D _MD whose signal level rises.

According to the above configuration, the counter circuit 28 that repeats the counting operation in the scanning cycle of the magnetic heads 20A and 20B supplies the predetermined setting data D at the timing when the magnetic heads 20A and 20B scan the synchronous signal recording area for ATF tracking control. By loading the _SET , the counting operation of the counter circuit 28 can be synchronized with the scanning timing of the magnetic heads 20A and 20B.

Therefore, by switching the recording / reproducing operation based on the count value of the counter circuit 28, the sub-code area can be detected with high accuracy and dubbing can be reliably performed.

In the above embodiment, the case where the magnetic tape is wound at a winding angle of 90 degrees has been described. However, the present invention is not limited to this, and can be widely applied to magnetic recording / reproducing apparatuses having various configurations.

Further, in the above-described embodiment, the case of recording / reproducing a digital audio signal has been described. However, the present invention is not limited to this, and is widely applied to a magnetic recording / reproducing apparatus which records / reproduces various data instead of the digital audio signal. be able to.

H Advantageous Effects of the Invention As described above, according to the present invention, ATF tracking is performed based on a rotating drum having a magnetic head on which a magnetic tape is wound at a predetermined winding angle, and a reproduction signal reproduced from the magnetic tape by the magnetic head. Detecting means for detecting a control synchronizing signal; counting means for repeating a counting operation sequentially in synchronization with a scanning cycle of the magnetic head; and a magnetic head for detecting a subcode area on the magnetic tape based on the count value of the counting means. Control signal generating means for generating a control signal indicating a scanning period of the data, mode switching means for switching the recording / reproducing mode based on the control signal generated by the control signal generating means, and ATF tracking control for detecting means. If no synchronization signal is detected, the subcode area on the magnetic tape is Output means for outputting a recording signal for post-recording that rewrites only the data. The recording / reproducing mode can be switched based on the count value of the counting means that repeats the counting operation, thereby realizing a magnetic recording / reproducing apparatus capable of detecting the subcode area with high accuracy and reliably performing the after-recording operation.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a digital audio tape recorder according to an embodiment of the present invention, and FIG. 2 is a signal waveform diagram for explaining the operation thereof. 1 ... Digital audio tape recorder, 2 ... Rotary drum, 10 ... Magnetic tape, 20A, 20B ... Magnetic head, 22 ... Switching pulse signal generation circuit, 26 ... Synchronization signal detection circuit, 28 ... Counter Circuit, 30... Decoder circuit, 34... Recording signal generation circuit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 27/28 G11B 15/467

Claims (1)

(57) [Claims] A synchronous drum for controlling ATF tracking is detected from a rotating drum having a magnetic head on which a magnetic tape is wound at a predetermined winding angle, and a reproduction signal reproduced from the magnetic tape by the magnetic head. Detecting means for performing the above operation, counting means for sequentially repeating a count operation in synchronization with a scanning cycle of the magnetic head, and a period in which the magnetic head scans a subcode area on the magnetic tape based on the count value of the counting means. Control signal generating means for generating a control signal indicative of: a mode switching means for switching a recording / reproducing mode based on the control signal generated by the control signal generating means; and a detecting means for controlling the ATF tracking control. If the synchronization signal has not been detected, based on the count value at the time of the previous detection, the Serial magnetic recording and reproducing apparatus characterized by comprising an output means for outputting a recording signal for after-recording to rewrite only the sub-code area.