JPH0544906Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention records an audio PCM signal on a magnetic recording medium using a rotating head on one diagonal track every unit time, and reproduces the same. The present invention relates to a magnetic recording and reproducing apparatus that can read subcode data without error, particularly when performing a high-speed search.

[Technical background of the invention and its problems] An audio signal is transmitted onto a magnetic recording medium every unit time by a helical scan type rotating head.
When recording diagonal tracks one by one and reproducing them, the audio signal is converted to PCM.
A magnetic recording and reproducing device called R-DAT (rotating head type digital audio tape recorder) is currently being developed as a device for recording and reproducing data by recording and reproducing data.

In this R-DAT, for example, two rotating heads are provided as shown in FIG.
Two rotating heads 1A and 1B are arranged on the rotating drum 3 at angular intervals of 180°. On the other hand, the magnetic tape 2 as a magnetic recording medium is wound along the circumferential surface of the rotating drum 3 in an angular range section of, for example, 90°.
Then, the rotary heads 1A and 1B rotate, for example, every minute.
The magnetic tape 2 is rotated at a speed of 2000 rpm, and the magnetic tape 2 is transferred at a predetermined running speed to the rotary head 1A.
and 1B, a diagonal track is formed on the magnetic tape 2 as shown in FIG. 4b, and a signal is recorded.

In order to improve the recording density, the width directions of the gaps of the rotary heads 1A and 1B are arranged in different directions with respect to the direction orthogonal to the scanning direction. That is, the azimuth angles are different, and the rotary head 1
A and 1B are each provided with an azimuth angle of ±20°.

As shown in Figure 4b, the track format in this R-DAT is centered around PCM data, with ATF signal areas for tracking on both sides, and AUX data is recorded on both sides of the center. subcode area (SUB
-1, SUB-2) are provided. In addition, each signal has a PLL area for synchronization, and there is a gap between each signal so that each signal can be recorded independently. .

In the above-mentioned R-DAT, since the wrapping angle of the magnetic tape around the rotating drum is as small as 90°, the magnetic tape cannot be wrapped around the rotating drum.
High-speed searches are possible using FF and REW, and by reading the search information recorded on the magnetic tape during this high-speed search, high-speed access to any location is possible. The above-mentioned high-speed search is performed by adjusting the running speed of the magnetic tape during normal recording and playback in order to read search information such as the program number of the song recorded on the magnetic tape, the cue signal of the song, and the absolute time in a short time. speed of 100 times or 200
This is done by setting the speed to about double the speed of the magnetic tape, and rotating the rotating drum on which the head is mounted at a speed that matches the double speed of the magnetic tape.

During this high-speed search, as in normal playback, in order to read the subcode data attached to each data to identify the data recorded on the magnetic tape, the signal reproduced during the search is read. A drum servo controls the rotation speed of the rotating drum to make the frequency the same as during normal reproduction, and the rotation of the reel for winding the magnetic tape is also controlled by a reel servo to maintain a constant speed.

When a conventional device performs a high-speed search from a stopped state, it is performed as follows.

Based on the input signal to instruct high-speed search, the system control unit drives and controls the reel servo system every time the drum is touched, and the drum motor and reel motor are turned on almost simultaneously to drive the rotation of the rotating drum and Winding drive of the magnetic tape is started. Then, when it becomes possible to read the subcode data recorded on the magnetic tape, the system control section reads the contents from the signal processing section and controls the servo while determining whether or not it is the search position that is the search target. The search operation continues while controlling the system.

As mentioned above, in the past, when performing a high-speed search from a stopped state, the drum motor and reel motor were turned on and driven almost simultaneously, so the rotation of the drum motor started up and was not recorded on the magnetic tape. Until the subcode data can be read, the rotation of the reel shaft causes the magnetic tape to enter the winding state at the speed used during high-speed search. Therefore, the subcode data cannot be read until the drum motor starts rotating, that is, when the high-speed search starts, and when a malfunction occurs when searching for music selection or absolute time, it is difficult to read the subcode data. A problem arose.

[Purpose of the invention] The present invention was devised to eliminate the above-mentioned conventional problems.When performing a high-speed search from a stopped state, the present invention detects that the rotational speed of the drum motor has locked and detects this. After checking,
It is an object of the present invention to provide a magnetic recording and reproducing device which prevents malfunctions during music selection operations and high-speed searches such as absolute time by turning on a reel motor and winding a magnetic tape.

[Summary of the idea]

The present invention controls the rotational speed of the rotating drum carrying the magnetic tape and head during the high-speed search so that the relative speed of the rotating drum matches the relative speed during normal playback when performing a high-speed search from a stopped state. A drum servo, a reel servo that controls the rotational speed of the reel that runs the magnetic tape, and a lock detection section that is installed in the drum servo and detects that the rotational speed of the drum motor is locked are provided to start a high-speed search. In some cases, the rotational drive of the reel motor is started after it is detected that the rotational speed of the drum motor is locked, so that the subcode data recorded on the magnetic tape can be reliably read even when a high-speed search is started. It was made so that it could be done.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing an embodiment of a magnetic recording/reproducing apparatus according to the present invention.

In the figure, 11 is a mechanism block, and heads 1A and 1B are arranged at an angular interval of 180°.
A rotary drum 3 having a magnetic tape 2 wound thereon in a 90° angular range section and rotationally driven by a drum motor 4, a reel motor 5 driving a reel shaft for winding the magnetic tape 2, and a magnetic tape 2. The vehicle is equipped with a capstan motor 6 that drives and controls the traveling speed of the vehicle to a constant value. The drum motor 4 is provided with a frequency generator 7 for detecting its rotation and a pulse generator 8 for generating head switching pulses, and the reel motor 5 and capstan motor 6 are also provided with a frequency generator 7 for detecting their respective rotations. Generators 9 and 10 are provided.

12 is an operation unit through which the user selects and operates operation modes such as recording, playback, and high-speed search; 13;
1 is a system control section that drives and controls the operations of the mechanism block 11 described above, a servo block 14 described later, a signal processing section 19, etc., based on instruction signals from the operation section 12. A servo block 14 includes a drum servo 15, a reel servo 16, a capstan servo 17, and a reference signal generation circuit 18. The drum servo 15 receives a signal from the frequency generator 7, a signal from the pulse generator 8, a reference signal from the reference signal generation circuit 18,
A regenerated PLL clock is supplied from the signal processing section 19, and a rotational drive control signal for controlling the rotational speed of the drum motor 4 is generated from this output. Note that the drum servo 15 described above has a lock detection section 15.
The lock detection section 15A detects that the rotational speed of the drum motor 4 is locked, and this lock detection signal is sent to the system control section 13.
is supplied to A signal from the frequency generator 9 and a reference signal from the reference signal generation circuit 18 are supplied to the reel servo 16, and a rotational drive control signal for controlling the rotational speed of the reel motor 5 is generated from this output. Further, the capstan servo 17 is supplied with a signal from the frequency generator 10, a reference signal from the reference signal generation circuit 18, and a tracking error signal from an ATF (Automatic Trac Finding) circuit 21 for tracking.
A rotational drive control signal for controlling the rotational speed of the capstan motor 6 is generated from this output. 19 is a signal processing section, and during recording, the input terminal (IN) is connected to the low-pass filter 22, A/
The recording signal supplied via the D converter 23 is supplied to the RF amplifier 20 after being subjected to necessary signal processing.
After performing the necessary signal processing on the playback signal from
It is output from the output terminal (OUT) via the D/A converter 24 and the low-pass filter 25, and the required output obtained by further signal processing is sent to the servo block 14.
The reference signal generation circuit 18 of FIG.

Next, the operation of the apparatus configured as described above during a high-speed search will be explained.

It is now assumed that the mechanism block 11 is in a stopped state. When an input operation to instruct high-speed search is performed using the operation unit 12, the system control unit 13 confirms that the operation mode is high-speed search, and the control signal from the system control unit 13 is transmitted to the servo block. The drum motor 4 is first turned on and driven to rotate. and,
Lock detection section 15 provided in drum servo 15
When it is detected by A that the rotational speed of the drum motor 4 has been locked, this lock detection signal is transmitted from the lock detection section 15A to the system control section 1.
3.

The system control unit 13 is the lock detection unit 1 described above.
When the lock detection signal from 5A is received, a control signal is supplied to the reel servo 16 of the servo block 14, and this time the reel motor 5 is turned on and the reel shaft is rotationally driven, thereby winding (or rewinding) the magnetic tape. The process starts from the time when the rotational speed of the drum motor 4 is locked. At this time, the reel servo 16 controls the rotation of the reel motor 5 so that the rotation starts gradually.

FIG. 2 shows an example of the actual circuit configuration of the reel servo 16 described above.

The reel servo 16 is a motor drive amplifier 1
6 ₁ , a buffer amplifier 16 ₂ , a switching transistor 16 ₃ , a time constant circuit 16 ₆ consisting of a resistor 16 ₄ and a capacitor 16 ₅ .
Note that T ₁ is an error signal input terminal, T ₂ is a soft start terminal, and T ₃ is an output terminal.

Soft start terminal _T2 is connected to system control unit 13
Normally, an "H" level signal is supplied to this soft start terminal _T2 from the system control unit 13, and the switching transistor ₁₆₃ is turned on, and the charge in the capacitor ₁₆₅ is transferred to the soft start terminal T2. It is discharged via the switching transistor ₁₆₃ , and the error signal input terminal _T1
An output signal corresponding to the error signal supplied to the motor drive amplifier 16 ₁ is extracted from the motor drive amplifier 16 1 and is supplied to the reel motor 5 from the output terminal T ₃ via the buffer amplifier 16 ₂ .

During a high-speed search, an "L" level signal is supplied from the system control section 13 to the soft start terminal _T2 . At this time, the switching transistor ₁₆₃ is turned off, and the output of the motor drive amplifier ₁₆₁ is connected to the resistor ₁₆₄ and the capacitor 16.
A time constant circuit ₁₆₆ consisting of ₅ and 5 is interposed.
Therefore, at the beginning of the high-speed search, the voltage supplied to the reel motor 5 gradually increases due to the time constant determined by the above-mentioned time constant circuit ₁₆₆ , so that the rotation of the reel motor 5 does not change at the above-mentioned time. It will be launched gradually over a period determined by a fixed number.

In addition, the system control unit 13 outputs “L” to the soft start terminal T ₂ of the reel servo 16 described above.
Almost simultaneously with the supply of the level signal, the input reference signal to the drum servo 15 is switched to the reproduction PLL clock (PB PLL CK) supplied from the signal processing section 19 instead of the reference signal from the reference signal generation circuit 18. As a result, the drum motor 4, whose rotation was previously controlled by the drum servo 15 based on the reference signal supplied from the reference signal generation circuit 18, is now controlled by the reproduction signal supplied from the signal processing section 19.
A drum servo that follows the rotational speed of the reel motor 5 is applied based on the PLL clock.

As described above, after the drum motor 4 is turned on and driven to rotate, and after detecting that the rotational speed of the drum motor 4 is locked, the reel motor 5 is turned on and rotated so as to gradually start up. By applying a drum servo that follows the rotational speed of the reel motor 5 to the drum motor 4, the sub recording on the magnetic tape 2 is started immediately after the reel motor 5 is turned on and rotated. Can read code data. Then, the system control unit 13 reads the contents of the read subcode data from the signal processing unit 19, and performs a high-speed search operation until the search for the search position is completed while determining whether the search position is the specified search target. The process continues, and when the search position is found, the process moves to the next instructed operation. Incidentally, FIG. 3 is a flowchart showing the above-mentioned operating procedure.

Further, as shown in FIG. 3, the operating procedures in the above-mentioned embodiment include driving the drum motor, detecting and confirming that the rotational speed of the drum motor is locked, driving the reel motor, and reproducing the input reference signal to the drum servo. Switching to PLL clock,
As explained in the procedure above, the input reference signal to the drum servo may be switched to the playback PLL control from the beginning.

That is, the procedure may be to switch the input reference signal to the drum servo to the regenerated PLL clock, drive the drum motor, confirm detection of locking of the rotational speed of the drum motor, and drive the reel motor.

〔effect〕

According to the present invention described above, when performing a high-speed search from a stopped state, first the drum motor is turned on and driven to rotate, and after detecting and confirming that the rotational speed of the drum motor has locked, the reel motor is turned on. Since the configuration is such that the drum motor is driven in rotation, it is possible that the magnetic tape will start running before the drum motor starts rotating, that is, before the subcode data recorded on the magnetic tape can be read. Therefore, even when a high-speed search operation is started near the search target position, subcode data can be reliably read, and malfunctions can be prevented when searching for music selection operations, absolute time, etc.

[Brief explanation of the drawing]

Fig. 1 is a block configuration diagram of a magnetic recording/reproducing device which is an embodiment of the invention, Fig. 2 is a circuit diagram showing an example of a reel servo of the invention, and Fig. 3 is an example of the operating procedure of the invention. The flowchart shown in FIG. 4 is a diagram for explaining the outline of R-DAT. 1A, 1B... Rotating head, 2... Magnetic tape, 3... Rotating drum, 4... Drum motor, 5
... Reel motor, 15 ... Drum servo, 15
A...Lock detection section, 16...Reel servo.

Claims (1)

[Claim for Utility Model Registration] In a magnetic recording/reproducing device that has a head mounted on a rotating drum and is capable of performing high-speed searches from a stopped state, there is a drum servo that controls the rotational speed of a drum motor that rotationally drives the rotating drum so that the speed matches the relative speed during normal playback; and a drum servo that controls the rotational speed of a reel motor that rotationally drives a reel that runs the magnetic tape. It is equipped with a reel servo and a lock detection section that is provided on the drum servo and detects that the rotational speed of the drum motor is locked, and detects that the rotational speed of the drum motor is locked at the start of high-speed search. A magnetic recording and reproducing device characterized in that a reel motor is later driven to rotate.