JPH10116449A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the damage of a magnetic tape by prerolling the magnetic tape at any point being within a specific range by a magnetic tape running system when a recording and reproducing part is in a recording and reproducing operation preparing state. SOLUTION: When a preroll command is supplied from a tape control circuit 22, the minimum preroll time preliminarily set in a minimum preroll time setting means 42 is detected and the maximum preroll time preliminary set in a maximum preroll time setting means 43 is detected and a randomization calculation is performed by a preroll time randomization calculating means 41 in order to disperse a preroll time in between the minimum preroll time and the maximum preroll time. Thus, parts in which the magnetic tape is to be touched with a recording and reproducing head as a rotary recording and reproducing means are dispersed based on this calculation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for recording, for example, recording data supplied from a host computer or supplying reproduced data to the host computer.

[0002]

2. Description of the Related Art Conventionally, there is a data recorder which operates as a tape streamer by providing an interface with a host computer in a drive device for recording digital data on a tape.

This data recorder is connected to a host computer via an interface unit, for example, a S
They are connected by a CSI interface. This interface unit has a formatter function for creating a file format on a tape and exchanging data on the file format in order to be recognized as a magnetic tape device by a host computer.

The interface unit has a buffer memory for temporarily storing data transferred between the host computer and the data recorder. The transfer operation of the data transfer between the host computer and the data recorder depends on the capacity of the buffer memory.

In other words, when the data recording speed on the data recorder side is constant, the data transfer speed and the mode of data transfer from the host computer are arbitrary, so that the buffer memory has a large capacity and high-speed data transfer is performed. Was like that.

Here, when the data to be recorded on the data recorder runs out, the data recording operation is stopped, the tape is rewound once to find the beginning, and the tape is run again. Recording was resumed at the same timing. Also, when the data recorder is not prepared to perform the data recording operation,
The host computer waits for data transfer.

In this case, in the data recorder, a predetermined tension is applied to the tape and the drum is rotated after a lapse of a predetermined period from a command to move the tape, so that a so-called standby-on state is set. This is to prevent tape damage caused by the contact surface of the drum sliding on a certain magnetic surface of the tape when the tape is stopped for a long time while the drum is rotated. Then, after this, the tape was run by the tape running system to perform recording or reproduction, and after recording or reproduction, the tension applied to the tape was released and the drum was stopped, so that a so-called standby-off state was established. .

On the other hand, a VTR (video tape recorder)
In the case of editing an image using, or performing on-air transmission, after pre-rolling to a position several seconds before the in-point indicating the recording / playback start position, by approaching from the pre-roll position, the in-point , An accurate recording or reproducing operation is performed.

Similarly, in the data recorder using the helical scan method, a predetermined tension is applied to the tape and the drum is rotated after a lapse of a predetermined period from a command to move the tape, so that a so-called standby-on operation is performed. Was in the state of. And after this,
The following operation was performed. First, as shown in FIG. 9, in step S20, the system controller of the data recorder receives the time designation of the in point from the interface unit. Next, in step S21, the system controller of the data recorder receives a pre-roll time designation set to a fixed value from the interface unit. After the system controller of the data recorder receives the pre-roll start command from the interface unit in step S22, in step S23, the system controller of the data recorder calculates a pre-roll position corresponding to the pre-roll time. Then, in step S24, the system controller of the data recorder sends a preroll operation command to the servo system so that the preroll is performed at a fixed preroll position with respect to the in point.

In this manner, the tape is pre-rolled to a position several seconds before the in-point by the tape running system, the approach is started from the pre-roll position, and the tape is run at a constant speed from the in-point to perform recording or reproduction. After recording or reproduction, the tension applied to the tape is released and the drum is stopped, so that the tape is in a so-called standby-off state.

[0011] Such a pre-roll operation is performed by moving the tape while searching for the pre-roll position, so that normal rotation and reverse rotation of the tape running and a sudden change in the tape running speed occur. Therefore, the tape near the pre-roll position is easily damaged. In addition, the tape at the pre-roll position continues to be damaged by the head trace because the tape at the pre-roll position is on standby at the pre-roll position until recording and reproduction start.

In order to prevent tape damage due to such standby-on, from the viewpoint of tape protection, when a command to move the tape is not received after a certain period of time, the tension applied to the tape is released and the drum is stopped. In this case, it is desirable to set a so-called standby-off state. However, if the command to move the tape is intermittent, every time the command to move the tape is interrupted,
Even in the standby-off state, if the pre-roll is repeated at the same position with respect to the same in point, the tape damage accumulates.

On the other hand, when an image is edited using a VTR or when air is sent out, it is not common to use the same in point repeatedly. In the recorder,
For management of data information, it is necessary to repeatedly read or write data at the same position recorded in, for example, a header portion. Therefore, pre-rolling to the same position is repeated, so that tape damage is concentrated.

[0014]

As described above, in the conventional data recorder, since the pre-roll position on the tape is fixed, the pre-roll is repeated to the same position, so that tape damage is caused at this pre-roll position. There was the inconvenience of concentrating.

The present invention has been made in view of the above points, and has as its object to provide a magnetic recording / reproducing apparatus capable of reducing tape damage caused by a pre-roll.

[0016]

The magnetic recording / reproducing apparatus of the present invention applies a predetermined tension to a magnetic tape and rotates a rotary recording / reproducing means to prepare for a recording / reproducing operation. By running the magnetic tape to record the recording data supplied from the data supply source on the magnetic tape, supply the reproduction data reproduced from the magnetic tape to the data supply source, after the recording and reproduction operation is completed, In a magnetic recording / reproducing apparatus having a recording / reproducing unit which releases a predetermined tension applied to the magnetic tape and stops the rotation of the rotary recording / reproducing means to bring the recording / reproducing operation to an end state, the recording / reproducing unit includes the recording / reproducing unit. In the reproducing operation preparation state, the magnetic tape traveling system prerolls the magnetic tape to any point within a predetermined range. A.

According to the present invention, the following operations are performed. First, when a recording operation (WR) command and recording data are supplied to the recording / reproducing unit from the data supply source, a control command for data signal processing and tape running control is supplied to the recording / reproducing unit.

An instruction is supplied to the recording / reproducing unit to control the addition of an error correction code or the like to the data in the signal processing and the control relating to the error correction processing. Also, an in-point command indicating a recording start point and a pre-roll command indicating a pre-roll start are supplied to the recording / reproducing unit.

In the present invention, in particular, when controlling the pre-roll time, randomization calculation of the pre-roll time is performed. A preset minimum pre-roll time is detected. The minimum pre-roll time is determined by the phase of the magnetic tape running system, and is the minimum time until the PLL circuit in the drive circuit locks the phase with respect to the capstan motor, the supply reel motor, and the take-up reel motor. The minimum pre-roll time is obtained by detecting a time until the phase lock signal of the PLL circuit is detected, and the minimum pre-roll time is set in the recording / reproducing unit in advance. Then, a predetermined minimum pre-roll time can be detected by a predetermined access.

Further, a preset maximum pre-roll time is detected. The maximum pre-roll time is the maximum time for recording data to be stored up to the maximum storage capacity of the buffer memory for temporarily storing recording data during data recording, and the reproduction data is stored up to the maximum free storage capacity of the buffer memory during data reproduction. It is the maximum time to be discharged. The maximum pre-roll time is previously calculated from the recording speed or the reproduction speed of the recording / reproducing unit with respect to the maximum storage capacity or the maximum free storage capacity of the buffer memory, and the maximum pre-roll time is set in the recording / reproducing unit in advance. Then, a predetermined maximum pre-roll time can be detected by a predetermined access.

The pre-roll time randomization calculation is performed using a random value equal to or longer than the minimum pre-roll time and equal to or shorter than the maximum pre-roll time. A pre-roll position corresponding to the pre-roll time calculated by the random value is calculated, and a pre-roll operation command is transmitted to a servo circuit of the tape traveling system so that the pre-roll is performed at the pre-roll position.

In this way, the tape is pre-rolled to a random position within the pre-roll range several seconds before the in-point by the tape running system, the approach starts from the pre-roll position, and the tape runs at a constant speed from the in-point. The recording or reproduction is performed, and after the recording or reproduction, the tension applied to the tape is released and the drum is stopped, so that a so-called standby-off state is set. In this way,
The portion where the magnetic tape hits the rotating recording / reproducing means during pre-rolling can be dispersed.

[0023]

FIG. 1 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to the present embodiment. First, the configuration of this device will be described. As shown in FIG. 1, the magnetic recording / reproducing apparatus includes a recording / reproducing unit 10 for recording / reproducing data.
And a recording / reproducing unit control device 1 that interfaces with a host computer and controls the operation of the recording / reproducing unit. The recording / reproducing unit control device 1 connects a host computer (not shown) and a data recorder as the recording / reproducing unit 10 by, for example, a SCSI interface or the like. The SCSI interface is SCSI (Sma
ll Computer System Interfa
ce: An interface conforming to ANSI X3.131-1986) standard. The host computer includes, for example, a file generation unit that converts various data such as document data, graphic data, program data, image data, and audio data into a file, and a communication unit that transmits or receives file data.

FIG. 2 shows the configuration of the recording / reproducing unit control device 1. The recording / reproducing unit control device 1 interfaces with a host computer and controls a recording / reproducing unit 10, and creates a specific format on a tape and exchanges data in the format. Control unit 24 for controlling data, buffer memory 25 for temporarily storing data between the host computer and recording / reproducing unit 10, and control data used for host interface control unit 20 and format control unit 24. And a control table 23 stored therein. Also, in this example,
The host interface control unit 20 has, as functional blocks, a data control circuit 21 for controlling a data processing system of the recording and reproducing unit 10 and a tape control circuit 22 for controlling a tape running system of the recording and reproducing unit 10.

The host interface control unit 20 controls the data recorder as the recording / reproducing unit 10 as if using a control program, as if by MT (Magnetic Tape).
It has a tape stream emulation function that is externally controlled to operate like a tape streamer such as a storage (magnetic tape storage device).

Here, the specific format created on the tape by the format control unit 24 is as follows. Specifically, a logical volume equivalent to one drive in a hard disk or the like is set on the tape, for example. In one logical volume, volume information (VSIT: Volume S) including position information of various data in the logical volume and the like is included.
et Information Table (DIT) is arranged, and subsequently, directory information (DIT: Directory Information) composed of information in the directory.
Tion Table) is arranged. In this format, data is, for example, 1 ID (= 4 tracks) of a tape.
Blocking of data by assigning track set ID numbers in units, processing of combining data at file breaks specified by the host computer, and addition of subcodes as data that can be searched for during playback At the same time, it is generated by processing such as creation of directory information based on the track set ID number.

The function of this format and the function of each unit will be described below. The volume information (VSIT) and the directory information (DIT) are stored in a logical starting position (LOBT: Logical Beginning O) of the tape.
f Tape). Directory information (DIT) includes file control information,
It is recorded on a tape so that the recording / reproducing unit 10 can search at high speed. Directory information (DIT)
When a tape is loaded into the recording / reproducing unit 10, the tape is read by the format control unit 24, and is read from the buffer memory 2.
5.

When a write command (WR) is issued from the host computer and the file data is subsequently supplied to the format control unit 24, the format control unit 2
4 sequentially accumulates the file data in the buffer memory 25 and sends the next write command (W
If R) is not issued, the buffer memory 25
EOD (End Of) at the end of the data stored in
After adding data called Data), the data stored in the buffer memory 25 is transferred to the recording / reproducing unit 10. The recording / reproducing unit 10 records the data supplied from the format control unit 24 so as to form a helical track on the tape.

Here, when the command is issued again from the host computer, the EOD described above is recognized by the format control unit 24 to which position on the tape the data is recorded, and based on this recognition, This is information necessary for controlling the recording / reproducing unit 10.

Next, if the command from the host computer is a write command (WR), the format control unit 24 stores the file data to be written next in the buffer memory 25 when the next file data is stored in the buffer memory 25. After the EOD is added to the end of the data, the data is transferred to the recording / reproducing unit 10, and the position of the tape of the recording / reproducing unit 10 is moved to the position of the EOD recorded on the tape. Thus, the data supplied to the recording / reproducing unit is sequentially recorded from the position of the EOD recorded on the tape. Therefore, the previously recorded EOD is erased by the next newly recorded data, and this new EO is erased.
By adding D, the user area is extended as a result.

During the data write operation by the write command (WR), the format control unit 24 updates the directory information stored in the buffer memory 25, and ends the data write operation by the write command (WR). Then, the directory information stored on the buffer memory 25 is recorded at the position of the directory information recorded on the tape, thereby updating the directory information on the tape. Therefore, the next time any command is supplied from the host computer,
The format control unit 24 is configured to read the updated directory information to always obtain accurate information of the directory on the tape, and to control the recording / reproducing unit 10 based on the accurate information. I have.

The host interface control means 2
The 0 data control circuit 21 has a communication unit for transmitting the file data reproduced by the recording / reproducing unit 10 and stored in the buffer memory 25 to the host computer and receiving the file data transmitted from the host computer.

The format control unit 24 generates a buffer memory state detecting unit for detecting the capacity of the buffer memory 25 at the time of communication with the host computer and generates directory information to generate the above-mentioned format. DIT), a directory information table forming unit, a directory information reading unit that reads directory information when a tape is loaded (threading), an identifier detecting unit that detects an identifier such as an EOD, and an EOD writing unit that writes an EOD to a buffer memory. Have.

The buffer memory 25 stores the above-mentioned volume information (VSIT), directory information (DIT), and the like. The contents such as volume information (VSIT) and directory information (DIT) stored in the buffer memory 25 are sequentially updated on the buffer memory 25 in accordance with the state of the recording / reproducing unit 10 during the recording operation.

The format control unit 24 also controls the recording / reproducing unit 1 when loading (threading) the tape.
0, the position of the directory information (DIT) on the tape is recognized by looking at the contents of the volume information (VSIT) stored in the buffer memory 25, and the recording / reproducing unit 10 is recognized based on this recognition. The control unit 10 controls the recording / reproducing unit 10 to read directory information (DIT) recorded on the tape. Recording and playback unit 1
Directory information (DIT) from 0 is stored in the buffer memory 25. Thus, the format control unit 24 can see the directory information (DIT) stored in the buffer memory 25.

That is, the format control unit 24 reads the volume information (VSIT) at the time of tape loading (threading), and determines the position of the directory information (DIT) on the tape based on the read contents of the volume information (VSIT). The directory information (DIT) is obtained by recognizing and controlling the recording / reproducing unit 10 based on the recognition.

Then, the format controller 24 controls the volume information (VSI
T), the control corresponding to the command from the host computer is performed based on the directory information (DIT) by the data control circuit 2 of the host interface control unit 20.
1 and the tape control circuit 22, the data control circuit 21 and the tape control circuit 2
2 to access the recording / reproducing unit 10.

In the recording / reproducing section 10 having such a format, in particular, the volume information (VSIT) and the directory information (DI
T) needs to be accessed frequently, and when a write command is issued again from the host computer, the tape is moved to the position of the EOD recorded on the tape to move from the position of the EOD recorded on the tape to the position of the EOD recorded on the tape. Since the volume information (VSIT), the directory information (DIT), and the EO
It is necessary to perform a pre-roll operation at a pre-roll position before the tape running direction when the position of D is set to the in point. The magnetic recording / reproducing apparatus according to the present embodiment, during this pre-roll, sets the position of the pre-roll to a random value within the pre-roll range between the minimum pre-roll time and the maximum pre-roll time, thereby reducing tape damage due to pre-roll at the same position. It is designed to decrease.

Although FIGS. 1 and 2 show only an example in which the recording / reproducing unit controller 1 is provided separately from the recording / reproducing unit 10, the recording / reproducing unit controller 1 is provided in the recording / reproducing unit 10. The configuration may be made in such a manner. FIG.
Has shown only an example in which the host interface control means 20 and the format control means 24 are separately provided in the recording / reproducing unit control apparatus 1, but the host interface control means 20 and the format control means 2
The data control circuit 21 and the tape control circuit 22 may be provided in the formatter as a formatter.

FIG. 3 shows a tape control circuit 2.
2 is a functional block diagram. In FIG. 3, the tape control circuit 22 has an in-point designating means 30 for designating an in-point which is a recording / reproducing start point, and a pre-roll command means 31 for sending a pre-roll start command. The in-point designating unit 30 has a function of supplying a command for moving the tape to the recording / reproducing unit 10 and positioning the tape at the in-point to the pre-roll control unit 40 of the system control circuit 4 in the recording / reproducing unit 10. Also, the pre-roll command means 31
Sends an instruction to the recording / reproducing unit 10 to move the tape to the pre-roll position in the reverse direction of the tape traveling direction, perform pre-rolling, and position the tape at the pre-roll point.
It has a function of supplying to the pre-roll control means 40 of the system control circuit 4 within 0.

The in point indicates, for example, the position of the volume information (VSIT), directory information (DIT) and EOD in the format described above. Therefore, a pre-roll start command is sent to perform a pre-roll operation at a pre-roll position before the IN point in the tape running direction. Here, the pre-roll time command indicating the pre-roll time is not supplied to the recording / reproducing unit 10. Also, even if the pre-roll time command is issued to the recording / reproducing unit 1
0, the recording / reproducing unit 10
In this case, the pre-roll control means 40 of the system control circuit 4 performs processing such that this command is ignored.

In FIG. 1, the recording / reproducing unit 10 comprises:
It has a signal processing system, a tape running system, and a system control circuit 4 for controlling the signal processing system and the tape running system. The signal processing system includes a signal processing circuit 2 for adding an error correction code and the like to the data and performing an error correction process, an RF circuit 3 for performing an equalizing process on the data, and a helical track provided on a drum 7 on a tape 7. And a recording / reproducing head 6 for forming The tape running system includes a servo circuit 5 for controlling the servo drive of the reel motor and the capstan motor, a tape 7, and reels 8 and 9 around which the tape 7 is wound and rotated by the reel motor. In this example, in particular, the system controller 4
Has a pre-roll control means 40 for randomizing the pre-roll time and dispersing the pre-roll position as a functional block.

FIG. 4 shows a functional block diagram of the system control circuit. The system control circuit includes a pre-roll control means 40 for randomizing the pre-roll time and controlling the pre-roll position to be dispersed, and a pre-roll position calculating means 4 for calculating the pre-roll position based on the tape traveling speed from the randomized pre-roll time.
4 and a pre-roll command to drive the capstan motor 52, the supply reel 53 and the take-up reel 54 via the drive circuit 50 of the servo circuit 5 to be rotated in the direction opposite to the tape running direction to position the pre-roll at the pre-roll position. And a pre-roll operation instructing means 45 for issuing. The pre-roll control means includes a minimum pre-roll time setting means 42 for setting a minimum pre-roll time, a maximum pre-roll time setting means 43 for setting a maximum pre-roll time, and dispersing a pre-roll time between the minimum pre-roll time and the maximum pre-roll time. And a pre-roll time randomizing calculating means 41 for performing randomizing calculation. Here, the minimum pre-roll time is a time determined by the phase adjustment in which the phase of the servo circuit 5 of the tape running system is locked, and the maximum pre-roll time is a time determined by the storage capacity of the buffer memory 25. That is, the minimum pre-roll time setting means 42 sets the detected phase of the servo system phase lock, for example, by detecting the phase lock signal of the PLL circuit of the servo circuit 5 of the tape running system. The maximum pre-roll time setting means 43 sets this time detected by detecting the storage capacity or free space of the buffer memory 25.

FIG. 5 is a block diagram of the servo circuit. The servo circuit includes a drive circuit 50 for driving each actuator, a drum motor 51 for rotating a drum on which a recording / reproducing head is mounted, a capstan motor 52 for rotating a capstan, and a supply reel motor 53 for rotating a supply reel. A take-up reel motor 54 for rotating the take-up reel, and a threading solenoid 55 for pulling out the tape and contacting the recording / reproducing head. The drive circuit 50 includes a drum motor 51, a capstan motor 52, a supply reel motor 53, and a take-up reel motor 5.
4. Positioning control and speed control are performed on the threading solenoid 55.

Here, the servo circuit 5 supplies an operation command from the system control circuit 4 of the recording / reproducing unit 10 based on a command from the tape control circuit 22 of the host interface control unit 20 in the recording / reproducing unit control device 1. It is configured to perform an operation by being performed.

Specifically, when a threading operation command from the system control circuit 4 is supplied to the drive circuit 50 of the servo circuit 5 based on a threading command from the tape control circuit 22, the servo circuit 5 A drive current is supplied from 50 to the threading solenoid 55, and the threading solenoid 55 has a function of drawing out the tape to a predetermined path and bringing the tape into contact with the drum at a predetermined angle to perform a threading operation.

Further, after the threading operation, the servo circuit 5 supplies a drive-on operation command from the system control circuit 4 to the drive circuit 50 of the servo circuit 5 based on a standby-on command from the tape control circuit 22. A drive current is supplied from the drive circuit 50 to the drum motor 51, and the drum motor 51 rotates at a predetermined speed in a state where a predetermined tension is applied to the tape, so that a standby-on operation is performed. Further, the servo circuit 5 has a function of performing a standby-off operation so as to perform an operation opposite to the above-described standby-on operation.

Further, after the standby-on operation, when the pre-roll operation command from the system control circuit 4 is supplied to the drive circuit 50 of the servo circuit 5 based on the pre-roll command from the tape control circuit 22, the servo circuit 5 drives A drive current is supplied from the circuit 50 to the capstan motor 52, the supply reel 53, and the take-up reel 54, and the capstan motor 523, the supply reel 53, and the take-up reel 5 are driven at a predetermined speed in a standby-on state.
4 has a function of rotating in the direction opposite to the tape running direction and positioning at the pre-roll position to perform a pre-roll operation.

The operation of the magnetic recording / reproducing apparatus thus configured will be described. First, an outline of the operation of the magnetic recording / reproducing apparatus will be described. The operation at the time of data recording will be described. During data recording, the file generation unit of the host computer sequentially generates file data. The file data generated by the file generation unit is transmitted to the host interface control unit 2 in the recording / reproduction unit control device 1 by the communication unit.
0 is supplied to the data control circuit 21. The file data supplied to the data control circuit 21 is sequentially supplied to the buffer memory 25 via the format control unit. The data control circuit 21 receives a write command (WR) from the host computer.

The buffer memory state detector of the format controller 24 detects whether the buffer memory is full. Writing is continued until the buffer memory becomes full, and when the buffer memory becomes full, the data control circuit 2 of the host interface control unit 20
1 and a write control signal for the recording / reproducing unit 10 to the tape control circuit 22. The EOD writing unit of the format control unit 24 is a buffer memory 25.
The EOD is written in the data area of the EOD.

The data control circuit 21 and the tape control circuit 2 of the host interface control unit 20
2 is a system control circuit 4 of the recording / reproducing unit 10 for transmitting a control signal for causing the recording / reproducing unit 10 to perform a write operation.
To supply. Thereby, the data read from the buffer memory 25 is sequentially supplied to the recording / reproducing unit 10,
It is recorded so as to form a helical track on the tape.

That is, the recording data compiled for each ID by the format control unit 24 of the recording and reproducing unit control device 1 is supplied to the signal processing system of the recording and reproducing unit 10. In the signal processing system, the recording data is added with an error correction code by the signal processing circuit 2 in the recording / reproducing unit 10 and is modulated so that it can be recorded on a tape. The signal-processed recording data is supplied to the RF circuit 3. The recording data is equalized by the RF circuit 3. When the tape is unloaded, directory information (DIT) stored in the buffer memory 15 is supplied to the recording / reproducing unit 10 and is recorded on the tape via a signal processing system.

On the other hand, in the tape running system, a predetermined tension is applied in a state where the tape 7 wound around the reels 8 and 9 is brought into contact with the drum at a predetermined angle by the threading solenoid 55, and the drum motor 51 applies the drum to the drum. The recording / reproducing head 6 provided in the above is rotated to be in a standby-on state. Thereafter, the capstan motor 52, the supply reel motor 53, and the take-up reel motor 54 are driven by the control of the servo circuit 5 to perform pre-roll. Then, data is recorded by the recording / reproducing head 6 while running the tape at a constant speed from the in point, which is the recording start point, for the first time starting from the pre-roll position.

Specifically, the tape control circuit 22
When a threading operation command from the system control circuit 4 is supplied to the drive circuit 50 of the servo circuit 5 based on the threading command from the drive circuit 50, a drive current is supplied from the drive circuit 50 to the threading solenoid 55, and the threading solenoid 55 Is drawn out to a predetermined path and brought into contact with the drum at a predetermined angle to perform a threading operation.

Further, after the threading operation, when a standby-on operation command from the system control circuit 4 is supplied to the drive circuit 50 of the servo circuit 5 based on a standby-on command from the tape control circuit 22, the drive circuit 50 A drive current is supplied to the motor 51, and the drum motor 51 rotates at a predetermined speed in a state where a predetermined tension is applied to the tape, whereby a standby-on operation is performed.

Further, after the standby ON operation, based on the pre-roll command from the tape control circuit 22,
When a pre-roll operation command from the system control circuit 4 is supplied to the drive circuit 50 of the servo circuit 5, a drive current is supplied from the drive circuit 50 to the capstan motor 52, the supply reel 53 and the take-up reel 54, and the standby ON state At a predetermined speed at the capstan motor 52,
The supply reel 53 and the take-up reel 54 rotate in the direction opposite to the tape running direction and are positioned at the pre-roll position, and the pre-roll operation is performed.

Here, the pre-roll time is randomized by the pre-roll control means 40 so that the pre-roll positions are dispersed on the tape so that tape damage due to the pre-roll is reduced. That is, the pre-roll control means 40 performs the following operation. When a pre-roll command is supplied from the tape control circuit 22, the minimum pre-roll time preset in the minimum pre-roll time setting means 42 is detected, and the maximum pre-roll time preset in the maximum pre-roll time detection means 43 is detected. A randomizing calculation is performed by the time randomizing calculating means 41 so as to disperse the preroll time between the minimum preroll time and the maximum preroll time.

Next, the data reproduction will be described. At the time of data reproduction, a read command (RD) from the host computer is supplied to the data control circuit 21 of the host interface control unit 20 in the recording and reproduction unit control device 1 by the communication unit. The data control circuit 21 receives a read command (RD) from the host computer.

The data control circuit 21 and the tape control circuit 2 of the host interface control unit 20
Reference numeral 2 denotes a system control circuit of the recording / reproducing unit 10 for transmitting a control signal for causing the recording / reproducing unit 10 to perform a read operation.
To supply. As a result, the helical track on the tape is sequentially reproduced in the recording / reproducing unit 10.

In the signal processing system, the reproduction signal from the tape 7 is supplied to the RF circuit 3. The reproduction signal is supplied to the signal processing circuit 2 after being equalized by the RF circuit 3. The reproduced data is subjected to error correction processing and the like in the signal processing circuit 2 and is supplied to the recording / reproducing unit control device 1. The reproduction data is subjected to processing such as recognition of a file break at the recording / reproduction unit control device 1. The data for which such processing has been completed is output in accordance with the file number and the requested data size from the host computer.

That is, in the recording / reproducing unit controller 1, the buffer memory state detector of the format controller 24 detects whether or not the buffer memory is full.
Writing of the reproduction data is continued until the buffer memory becomes full. When the buffer memory becomes full, the format control unit 24 sends the recording / reproduction unit 10 to the data control circuit 21 and the tape control circuit 22 of the host interface control unit 20. Supply a read stop control signal to Further, the format control unit 24 detects the EOD of the EOD data area of the buffer memory 25.

On the other hand, in the tape running system, a predetermined tension is applied in a state where the tape 7 wound around the reels 8 and 9 is brought into contact with the drum at a predetermined angle by the threading solenoid 55, and the drum motor 51 applies the predetermined tension. The recording / reproducing head 6 provided in the above is rotated to be in a standby-on state. Thereafter, the capstan motor 52, the supply reel motor 53, and the take-up reel motor 54 are driven by the control of the servo circuit 5 to perform pre-roll. Then, data is reproduced by the recording / reproducing head 6 while running the tape at a constant speed from the in point, which is the reproduction start point, for the first time from the pre-roll position into the run.

Specifically, the tape control circuit 22
When a threading operation command from the system control circuit 4 is supplied to the drive circuit 50 of the servo circuit 5 based on the threading command from the drive circuit 50, a drive current is supplied from the drive circuit 50 to the threading solenoid 55, and the threading solenoid 55 Is drawn out to a predetermined path and brought into contact with the drum at a predetermined angle to perform a threading operation.

Further, after the threading operation, when the standby-on operation command from the system control circuit 4 is supplied to the drive circuit 50 of the servo circuit 5 based on the standby-on command from the tape control circuit 22, the drive circuit 50 A drive current is supplied to the motor 51, and the drum motor 51 rotates at a predetermined speed in a state where a predetermined tension is applied to the tape, whereby a standby-on operation is performed.

Further, after the standby ON operation, based on the pre-roll command from the tape control circuit 22,
When a pre-roll operation command from the system control circuit 4 is supplied to the drive circuit 50 of the servo circuit 5, a drive current is supplied from the drive circuit 50 to the capstan motor 52, the supply reel 53 and the take-up reel 54, and the standby ON state At a predetermined speed at the capstan motor 52,
The supply reel 53 and the take-up reel 54 rotate in the direction opposite to the tape running direction and are positioned at the pre-roll position, and the pre-roll operation is performed.

That is, at the time of data reproduction, a predetermined tension is applied in a state where the tape 7 wound around the reels 8 and 9 is brought into contact with the drum at a predetermined angle by the threading solenoid 55, and the drum motor 51 , The recording / reproducing head 6 provided at the second position is rotated to be in a standby-on state. After this, the servo circuit 5
, The capstan motor 52, the supply reel motor 53, and the take-up reel motor 54 are driven to perform pre-rolling. Then, the data is reproduced by the recording / reproducing head 6 while the tape is running at a constant speed from the pre-roll position to the in point which is the reproduction start point. Here, the pre-roll time is randomized by the pre-roll control means 40 so that the pre-roll positions are dispersed on the tape, and tape damage due to the pre-roll is reduced.

Here, the pre-roll time is randomized by the pre-roll control means 40 so that the pre-roll positions are dispersed on the tape so that tape damage due to the pre-roll is reduced. That is, the pre-roll control means 40 performs the following operation. The minimum pre-roll time preset in the minimum pre-roll time setting means 42 is detected, and the maximum pre-roll time preset in the maximum pre-roll time setting means 43 is detected,
The randomizing calculation is performed by the preroll time randomizing calculating means 41 so as to disperse the preroll time between the minimum preroll time and the maximum preroll time.

As described above, the system control circuit 4 controls the servo circuit 5 to control the cueing of the tape 7 or to perform recording / reproduction in response to a request from the tape control circuit 22 of the recording / reproduction unit control device 1. Control unit 1
According to the request from the data control circuit 21 of
The signal processing of the signal processing circuit 2 at the time of recording and reproduction is controlled. In this example, in particular, the pre-roll control means 40 in the system control circuit 4 randomizes the pre-roll value between the maximum pre-roll time and the minimum pre-roll time by the in-point designation and the pre-roll command from the tape control circuit 22. It operates to calculate and control the pre-roll positions to be dispersed on the tape.

FIG. 8 is a diagram for explaining the operation of the magnetic recording / reproducing apparatus of the present embodiment. Data 81 is recorded on the tape 80 in front of the recording direction, as indicated by diagonal lines.
The minimum pre-roll position 83 is a position moved from the IN point 82 indicating the recording end point in the direction opposite to the recording direction by the minimum pre-roll time T _MIN . A position moved from the in point 82 in the direction opposite to the recording direction by the maximum pre-roll time T _MAX is the maximum pre-roll position 84. Here, a range longer than the minimum pre-roll time T _{MIN and} shorter than the maximum pre-roll time T _MAX is the pre-roll range TP. Control is performed so that the pre-roll time is randomized in the pre-roll range TP. The pre-roll position is used to advance the tape in preparation for a case where continuous shooting is performed by continuous recording from the in point 82 indicating the recording end point. Accordingly, the minimum pre-roll time T _MIN is determined by the PL in the drive circuit 50 with respect to the capstan motor 52, the supply reel motor 53, and the take-up reel motor 54 for recording.
The length is set to the minimum length necessary for the servo lock performed by the L circuit. Further, the maximum pre-roll time T _MAX is set to the maximum length for storing the recording data up to the maximum storage capacity of the buffer memory 25. The minimum pre-roll time T _MIN and the maximum pre-roll time T _MAX described above are
It does not indicate the actual time of the pre-roll, but indicates the logical length on the tape from the in point to the pre-roll position.

FIG. 6 is a flowchart showing the operation of the magnetic recording / reproducing apparatus of this embodiment. The operation of each step in this flowchart is the operation of the system controller 4 in the recording / reproducing unit 10. First, when a recording operation command (WR) and recording data are supplied from the host computer to the recording / reproducing unit controller 1, the data control circuit 21 and the tape control circuit are provided in the host interface controller 20 of the recording / reproducing unit controller 1. 22 is a system control circuit 4 of the recording / reproducing unit 10.
And a control command for data signal processing and tape running control.

Specifically, the data control circuit 21
Supplies a command for causing the system control circuit 4 to control the addition of an error correction code or the like to the data in the signal processing circuit 2 and the error correction processing. Further, the tape control circuit 22 supplies an in-point command indicating a recording start point and a preroll command indicating a preroll start to the system control circuit 4. Step S1
In step S2, the system control circuit 21 receives the in-point command and the pre-roll command.

In this example, in particular, in step S3, the pre-roll control means 40 in the system control circuit 21 performs a random calculation of the pre-roll time. FIG.
9 shows a flowchart of the operation of randomizing the pre-roll time. Specifically, in FIG.
At 10, the minimum pre-roll time T _MIN set in the minimum pre-roll time setting means 42 is detected. The minimum pre-roll time T _MIN is a minimum time until the PLL circuit in the drive circuit 50 locks the phase of the capstan motor 52, the supply reel motor 53, and the take-up reel motor 54. The minimum pre-roll time T _MIN can be obtained by detecting the time until the phase lock signal of the PLL circuit is detected. For example, the minimum pre-roll time T _MIN is set in the minimum pre-roll time setting means 42 at the time of factory shipment. Then, the minimum pre-roll time T _MIN set by the minimum pre-roll time setting means 42 can be detected by a predetermined access.

In step S11, the maximum pre-roll time T _MAX set in the maximum pre-roll time setting means 43 is detected. The maximum pre-roll time T _MAX is the maximum time during which recording data is accumulated up to the maximum storage capacity of the buffer memory 25 during data recording, and the maximum pre-roll time at which reproduction data is discharged up to the maximum free storage capacity of the buffer memory 25 during data reproduction. It is a limited time. Maximum pre-roll time T
_MAX is calculated in advance from the recording speed or the reproducing speed of the recording / reproducing unit 10 with respect to the maximum storage capacity or the maximum free storage capacity of the buffer memory 25, and is set in the maximum pre-roll time setting means 43 at the time of factory shipment, for example. To do. Then, the maximum pre-roll time T _MAX set by the maximum pre-roll time setting means 43 can be detected by a predetermined access.

[0074] preroll randomized calculating unit 41 in step S12, the minimum preroll T _MIN or more,
A random value less than or equal to the maximum pre-roll time T _MAX is calculated. Specifically, the minimum pre-roll time T _MIN is 2.0
The pre-roll range TP when the maximum pre-roll time T _MAX is 2.2 seconds is divided into, for example, 10 equal parts and shifted by 0.02 seconds. In this case, the previous pre-roll time is stored, and the current pre-roll time is shifted by at least 0.02 seconds so as to be at least different from the previous pre-roll time. Also, the pre-roll range TP is set to 10
A random value may be obtained by taking an exclusive OR (EXOR) of the data of the equally divided points and a predetermined bit stream.

In step S4, the system control circuit 4 of the recording / reproducing unit 10 calculates a pre-roll position corresponding to the pre-roll time calculated as a random value. Then, the system control circuit 4 of the recording / reproducing unit 10 sends a pre-roll operation command to the servo circuit 5 in step S5 so that the pre-roll is performed at the pre-roll position.

In this way, the tape is pre-rolled to a random position within a pre-roll range several seconds before the in-point by the tape running system, the approach starts from the pre-roll position, and the tape runs at a constant speed from the in-point. The recording or reproduction is performed, and after the recording or reproduction, the tension applied to the tape is released and the drum is stopped, so that a so-called standby-off state is set.

Although the data recorder has been described in the above example, it is needless to say that the invention can be applied to a helical scan video tape recorder.

In the above example, the operation at the time of data recording has been mainly described with reference to FIGS. 6 and 7, but the preroll time can be similarly controlled to a random value at the time of reproduction.

In the above example, when a command to move a tape for recording or the like is not received in the standby-on state, the system control circuit 4 inside the recording / reproducing unit 10 as a data recorder is controlled by the servo circuit 5 via the servo circuit 5. 5, an example in which the pre-roll time of the tape 7 is controlled to a random value by the reels 8 and 9 has been described, but from the host computer side or another device that performs the same operation via the interface, for example, from a dedicated experiment data collection device. You may make it control.

According to the above example, after a predetermined tension is applied to the magnetic tape and the rotary recording / reproducing means is rotated to prepare for the recording / reproducing operation, the magnetic tape is run by the magnetic tape traveling system to read the data. The recording data supplied from the supply source is recorded on the magnetic tape, the reproduction data reproduced from the magnetic tape is supplied to the data supply source, and after the recording / reproduction operation is completed, the predetermined data given to the magnetic tape is In the magnetic recording / reproducing apparatus having the recording / reproducing unit 10 which releases the tension and stops the rotation of the rotary recording / reproducing means to end the recording / reproducing operation, when the recording / reproducing unit 10 is in the recording / reproducing operation preparation state, Since the magnetic tape is pre-rolled to any point within a predetermined range by the magnetic tape traveling system, wear of the magnetic tape 7 is reduced. Parts manner without concentrating, the recording and reproducing head 6 as the magnetic tape 7 is rotated reproducing means
By dispersing the portion corresponding to, the tape damage due to the pre-roll can be reduced.

Further, according to the above example, in the above description, the pre-roll point is determined by randomizing calculation within the above-described predetermined range, so that the portion where the magnetic tape 7 hits the recording / reproducing head 6 as the rotary recording / reproducing means is determined. It can be further dispersed.

Further, according to the above example, in the above description, the predetermined range is longer than at least the minimum pre-roll time determined by the phase adjustment of the magnetic tape running system. The recording or reproducing operation can be performed from the beginning, and the portion where the magnetic tape 7 hits the recording / reproducing head 6 as the rotary recording / reproducing means can be dispersed.

According to the above example, in the above description, the predetermined range is shorter than the maximum pre-roll time determined by at least the storage capacity of the buffer memory for temporarily storing the recording data or the reproduction data. It is possible to operate the recording / reproducing operation of the unit 10 at the maximum recording / reproducing speed without stopping the recording / reproducing operation.
Can be dispersed at the position corresponding to the recording / reproducing head 6 as the rotating recording / reproducing means.

[0084]

According to the present invention, the magnetic tape is caused to travel by the magnetic tape traveling system after a predetermined tension is applied to the magnetic tape and the rotary recording / reproducing means is rotated to prepare for the recording / reproducing operation. The recording data supplied from the data supply source is recorded on the magnetic tape, and the reproduction data reproduced from the magnetic tape is supplied to the data supply source. In a magnetic recording / reproducing apparatus having a recording / reproducing unit which releases a predetermined tension and stops the rotation of the rotary recording / reproducing means to end the recording / reproducing operation, when the recording / reproducing unit is in the recording / reproducing operation preparation state, Since the magnetic tape is pre-rolled to any point within a predetermined range by the magnetic tape traveling system, the wear of the magnetic tape 7 is locally reduced. Not concentrated on, by dispersing a portion magnetic tape 7 hits the recording head 6 as a rotation recording and reproducing means, an effect that it is possible to reduce the tape damage.

Further, according to the present invention, in the above description, the preroll point is determined by randomizing calculation within the predetermined range, so that the portion where the magnetic tape 7 hits the recording / reproducing head 6 as the rotary recording / reproducing means. There is an effect that the particles can be further dispersed.

Further, according to the present invention, in the above description, the predetermined range is longer than at least the minimum pre-roll time determined by the phase adjustment of the magnetic tape running system. Recording or reproduction operation can be performed from the
Has an effect that the portion corresponding to the recording / reproducing head 6 as the rotating recording / reproducing means can be dispersed.

According to the present invention, in the above description, the predetermined range is smaller than a maximum pre-roll time determined by at least a storage capacity of a buffer memory for temporarily storing the recording data or the reproduction data. It is possible to operate at the maximum recording / reproducing speed without stopping the recording / reproducing operation of the unit 10 and to disperse the portion where the magnetic tape 7 hits the recording / reproducing head 6 as the rotary recording / reproducing means. .

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating a configuration of a recording / reproducing unit control device according to an embodiment of the magnetic recording / reproducing device of the present invention.

FIG. 3 is a functional block diagram illustrating a configuration of a tape control circuit according to an embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 4 is a functional block diagram illustrating a configuration of a system control circuit according to an embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 5 is a block diagram illustrating a configuration of a servo circuit according to an embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 6 is a flowchart showing the operation of pre-roll time randomization of the embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 7 is a flowchart showing an operation of a pre-roll time randomization calculation in one embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 8 is a diagram for explaining the operation of one embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 9 is a flowchart showing a conventional operation of a fixed pre-roll time.

[Explanation of symbols]

1 recording / reproducing unit control device, 2 signal processing circuit, 3 RF
Circuit, 4 system control circuit, 5 servo circuit, 6 recording / reproducing head, 7 tape, 8 reel, 9
Reel, 10 recording / reproducing unit, 20 host interface control unit, 21 data control circuit, 22
Tape control circuit, 23 control table, 24
Format control unit, 25 buffer memory, 30 in-point designation means, 31 pre-roll command means, 40 pre-roll control means, 41 pre-roll time randomization calculation means, 42 minimum pre-roll time setting means, 43 maximum pre-roll time setting means, 44 pre-roll position calculation means 45 pre-roll operation command means, 50 drive circuit, 51 drum motor, 52 capstan motor, 53 supply motor, 54 take-up motor, 55 threading motor, 80 tape, 81 recorded data, 82 in point, 83 minimum pre-roll position , 83
Maximum pre-roll position, T _MIN Minimum pre-roll time, T
_MAX maximum pre-roll time, TP pre-roll range

Claims (4)

[Claims] After applying a predetermined tension to a magnetic tape and rotating a rotary recording / reproducing means to prepare for a recording / reproducing operation, the magnetic tape is run by the magnetic tape traveling system and supplied from a data supply source. The recorded data to be recorded is recorded on the magnetic tape, the reproduced data reproduced from the magnetic tape is supplied to the data supply source, and after the recording / reproducing operation is completed, the predetermined tension applied to the magnetic tape is released. A magnetic recording / reproducing apparatus having a recording / reproducing unit which stops the rotation of the rotating recording / reproducing means and terminates the recording / reproducing operation, when the recording / reproducing unit is in the recording / reproducing operation preparation state,
A magnetic recording / reproducing apparatus wherein the magnetic tape is pre-rolled to any point within a predetermined range by the magnetic tape traveling system. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the pre-roll point is determined by randomizing calculation within the predetermined range. 3. The magnetic recording / reproducing apparatus according to claim 1, wherein the predetermined range is longer than at least a minimum pre-roll time determined by a phase adjustment of the magnetic tape traveling system. 4. The magnetic recording / reproducing apparatus according to claim 1, wherein the predetermined range is smaller than at least a maximum pre-roll time determined by a storage capacity of a buffer memory for temporarily storing the recording data or the reproduction data. Characteristic magnetic recording / reproducing device.