JPH11203644A - Speed control method of information recording medium - Google Patents

Abstract

(57) [Problem] To provide a speed control method for an information recording medium capable of controlling the traveling speed at a low cost and with higher accuracy when recording / reproducing a high density information recording medium. An information recording medium applied to the present invention includes a plurality of information recording tracks (I, II) in which data blocks (1-1, 2-1,...) And gap portions (3, 3,. ,... VII) are arranged in parallel and parallel to the traveling direction, and the servo burst signal recording section (5-1) is provided in the continuous area (3A) of the gap section over each information recording track (I, II,. , 5-2...) And the signal non-recording portion (6-
1, 6-2...) Are alternately arranged in a direction orthogonal to the traveling direction. In the speed control of the present invention, the servo burst signals recorded in the servo burst signal recording units (5-1, 5-2...) Are used as clock signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the speed of an information recording medium, and more particularly, to controlling the traveling speed at a low cost and with higher accuracy when recording / reproducing a high-density information recording medium. The present invention relates to an information recording medium speed control method that can be performed.

[0002]

2. Description of the Related Art In an information recording medium such as a tape streamer, a track density is increased in order to increase a recording density and reduce a size. A servo for tracking is replaced with an open loop control using a conventional stepping motor. Various techniques have been proposed for controlling the position of a recording / reproducing head with high accuracy by recording a signal. The present inventors have already applied for a patent for the novel technology relating to the high-density information recording medium as an information recording medium and a recording / reproducing method thereof (Japanese Patent Application No. 8-33700).
9).

In the information recording medium disclosed in the above-mentioned application, a plurality of information recording tracks in which data blocks and gap portions are alternately arranged are arranged in parallel and parallel to the traveling direction, and the gap portions extending over each information recording track are arranged. Is a medium in which a specific servo burst portion is formed in a direction perpendicular to the running direction in a continuous area of the medium. In recording / reproducing on such an information recording medium, a recording / reproducing head having a plurality of head gaps is used, and recording / reproducing from the center of the information recording track is performed based on a change in the intensity of the reproduced signal obtained from the servo burst section. A deviation of the position of the reproducing head is detected, and the position of the recording / reproducing head is controlled with high accuracy based on the deviation.

[0004] The traveling speed of the information recording medium is as follows.
Normally, means for processing a signal generated by the frequency generation pattern on the motor side, measuring the number of rotations of the capstan, or detecting a clock signal separately written on the medium with a fixed head is used. Controlled.

[0005]

In the above-described high-density information recording medium, it is necessary to control the traveling speed with high accuracy. However, according to the conventional speed control method, finer setting of the frequency generation pattern and more complicated arithmetic processing of the generated signal are required, and an encoder for measuring the rotation speed of the capstan is required. In addition, since two heads, a head for reading a servo signal and a head for reading a clock signal, are required, the cost of a drive device is increased, and a higher density and a lower price are promoted. I can't satisfy the practical demands.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to record / reproduce information recording media having a high density as described above and to operate at a low cost and with higher precision. An object of the present invention is to provide a method for controlling the speed of an information recording medium capable of controlling the speed.

[0007]

According to the present invention, there is provided a method for controlling a speed of an information recording medium, comprising:
In the information recording medium, a plurality of information recording tracks in which a data block of a predetermined length and a gap portion are alternately continuous are arranged in parallel and parallel to a traveling direction, and the gap portion over the information recording tracks is The continuous area is provided with a servo burst section in which servo burst signal recording sections and signal non-recording sections are alternately arranged in a direction orthogonal to the traveling direction, and the servo burst extended perpendicular to the traveling direction. The signal recording section is formed with a length of at least twice the arrangement pitch of the information recording tracks, and in the speed control, the servo burst recorded in the servo burst signal recording section of the servo burst section is used. The signal is used as a clock signal.

That is, in the above speed control method, the running speed of the information recording medium is controlled by using the servo burst signal as a clock signal. Therefore, in the process of creating the information recording medium, the operation of writing the clock signal is not necessary, and the drive device does not need to separately provide a mechanism for generating a control signal for speed control.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for controlling the speed of an information recording medium according to the present invention will be described with reference to the drawings. FIG.
FIG. 3 is a schematic plan view showing an information recording track and a servo burst portion of an information recording medium applied to the speed control method of the present invention, partially enlarged. FIG. 2 is a schematic plan view showing the relationship between the position of the head gap of the recording / reproducing head and the servo burst signal to be used. FIG. 3 is a flowchart showing an outline of a running speed control algorithm.

The speed control method of the present invention is disclosed in Japanese Patent Application No. 8-33.
This is applied to the information recording medium disclosed in No. 7009. As shown in FIG. 1, such an information recording medium includes a data block (1-1, 2-1,...) Having a predetermined length and a gap portion (3, 3).
..) Alternately continue on a plurality of information recording tracks (I 1, I 2
,... VII) are arranged in parallel with the traveling direction.
In FIG. 1, for convenience of explanation, reference numerals (I, II,... VII)
The case where there are seven information recording tracks, as shown by, is illustrated, and only portions related to tracking control and speed control of the information recording medium are extracted and shown. A set of one data block in the information recording tracks (I, II,... VII) is denoted by code (1-1, 1-2. , 2-2
.. 2-7).

Further, each information recording track (I, II,... VI
In the continuous region (3A) of the gap portion (3) over I),
A data ID signal section (9, 9...) And a servo burst section (4) corresponding to the information recording tracks (I, II,... VII) are provided. The data ID signal section (9) is provided as necessary for the purpose of recording information such as a distance from a data recording start point and a track number. Servo burst part (4)
Is provided for controlling the tracking of the head (7) (recording / reproducing head). Servo burst part (4)
Are composed of servo burst signal recording sections (5-1, 5-2...) And signal non-recording sections (6-1, 6-2...) Arranged alternately in a direction orthogonal to the running direction.

The servo burst signal recording sections (5-1, 5-2,...) Extended in the direction perpendicular to the running direction are arranged at an array pitch (track arrangement interval) of the information recording tracks (I, II,... VII). ., And the signal non-recording portions (6-1, 6-2,...) Have the same length as the servo burst signal recording portions (5-1, 5-2,...). Is done. Moreover, servo burst signal recording units (5-1, 5-2 ...)
Each of the boundary lines between the signal-free recording portions (6-1, 6-2,...) Extends in the traveling direction.
It is set so as to be located substantially at the center of the information recording track shown in (V) and (VII).

A head (7) disposed opposite to the recording surface of the information recording medium reads and writes signals.
One or more head gaps (recording / reproduction head gaps), preferably four head gaps (8-1) to
(8-4) are provided at intervals equal to the arrangement pitch of the information recording tracks (I, II,... VII), and the head (7)
Are designed to simultaneously read or write signals by these head gaps (8-1, 8-2...). As described above, the head gap (8-1, 8-2)
..) Enables accurate tracking control.

That is, the tracking control in the information recording medium is performed with four head gaps (8-1, 8).
-2...) And a servo burst signal recording section (5-1, 5-) of the servo burst section (4).
2), the head (7) from the center of the information recording track (I, II,.
The deviation of the position of is detected. Then, based on the detected deviation, at least one head gap (8-1), (8
Or (8-4) is the servo burst signal recording section (5-1), (5-2)... Or (5-7) and the signal non-recording section (6-1), (6-2) .. Or (6-7), in other words, four head gaps (8-
The high-density information recording tracks (I, II) are controlled by controlling the head (7) so that the phase difference between the reproduction signals of the two pairs of head gaps in (1) to (8-4) becomes 90 degrees. ,…
With respect to VII), the position of the head (7) can be controlled with high accuracy.

According to the speed control method of the present invention, in the above information recording medium, the servo burst signal recorded in the servo burst signal recording section (5-1, 5-2...) Of the servo burst section (4) is converted into a clock signal. The biggest feature is that it is used as

Specifically, as shown in FIG. 2, the servo used by the four positions (A) to (D) where the head (7) is located with respect to the information recording tracks (I, II,... VII). Set the burst signal. First, when the head (7) is located at the position (A) and between the positions (A) and (B), four head gaps (8-1, 8-2,...) While the head gap (8-1) is running, the servo burst signal recording unit (5-
Since the signal is superimposed on 1), the signal of the servo burst signal recording section (5-1) can be completely read by the head gap (8-1). Therefore, when the head (7) is located between the positions (A) and (B), the servo burst signal obtained by the head gap (8-1) is used as a clock signal.

Next, when the head (7) is located between the positions (B) and (C), the head gap (8-4) is similarly set to the servo burst signal recording section (5-2).
The servo burst signal obtained by the head gap (8-4) is used as a clock signal. When the head (7) is located between the positions (C) and (D), the servo burst signal obtained by the head gap (8-3) is similarly used as a clock signal. Position (D)
If it is located between (A) and (A), the servo burst signal obtained by the head gap (8-2) is used as a clock signal.

As described above, the four head gaps (8-
1, 8-2...), While the information recording medium is running,
Since the signal is always superimposed on any of the servo burst signal recording sections (5-1, 5-2...), The servo burst signal can be detected at a constant time interval proportional to the traveling speed. Therefore,
Using a suitable algorithm, a clock signal can be generated from the servo burst signal, and the speed of the information recording medium can be controlled by the clock signal.

As the above control algorithm, for example, an algorithm as shown in FIG. 3 can be mentioned. That is, in controlling the traveling speed of the information recording medium, first, each head gap (8-1,
8-2...), The servo burst signals are read out (step (S1)). Next, after the obtained peak values of the servo burst signals are detected by the arithmetic processing circuit of the drive device, these are converted into digital signals (step (S2)). Then, an operation of a Boolean algebraic OR function is performed from the position of the head (7) and the converted digital signals to select one digital signal and generate it as a predetermined clock signal (step (S)
3)).

Subsequently, the counter is reset by the generated clock signal, and the counter value at the time of resetting is stored (step (S4)). Next, the stored counter value is compared with a preset traveling speed set value (step (S5)). As a result of the comparison, if the counter value is within a predetermined allowable range with respect to the set value, the motor torque is maintained and the traveling speed is maintained (step (S6)).

On the other hand, when the counter value is out of the allowable range of the set value, the level of the counter value is further determined (step (S7)). As a result, when the counter value is lower than the allowable range of the set value, The motor speed is increased to increase the traveling speed (step (S8)). If the counter value is higher than the allowable range of the set value, the motor torque is decreased to decrease the traveling speed (step (S9)). Then, by repeating the above steps, the traveling speed of the information recording medium is maintained at the determined constant speed.

As described above, in the speed control method of the present invention,
Since the servo burst signal is used as a clock signal to control the traveling speed of the information recording medium, it is not necessary to separately perform a clock signal writing operation in the process of creating the information recording medium. There is no need to separately provide a control signal generation mechanism for speed control. Therefore, when recording / reproducing a high-density information recording medium, the traveling speed can be controlled at low cost and with high accuracy by a simple control algorithm.

In the speed control method of the present invention,
As in the above embodiment, two or more head gaps (8
-1, 8-2...) Are used,
By positioning at least one head gap in the servo burst signal recording section (5-1, 5-2...) And controlling the speed based on the timing of the reproduced waveform obtained from the servo burst signal recording section, higher precision is achieved. In addition, the traveling speed of the information recording medium can be controlled.

In particular, in particular, the servo burst signal recording section (5-
The length of the information recording tracks (I, II,...)
VII) is set to twice the arrangement pitch, and four head gaps (8-1, 8-) are set at intervals equal to the arrangement pitch.
The traveling speed of the information recording medium can be controlled with even higher precision by controlling the speed using the head (7) provided with 2).

[0025]

As described above, according to the information recording medium speed control method of the present invention, the servo burst signal is used as a clock signal to control the traveling speed of the information recording medium. In recording / reproducing the recorded information recording medium, the traveling speed can be controlled at low cost and with high accuracy by a simple control algorithm.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an information recording track and a servo burst portion of an information recording medium in a partially enlarged manner.

FIG. 2 is a schematic plan view showing a relationship between a position of a head gap of a recording / reproducing head and a servo burst signal to be used.

FIG. 3 is a flowchart showing an outline of a traveling speed control algorithm.

[Explanation of symbols]

 1-1, 2-1 ...: data block 1-2, 2-2 ...: data block 3: gap section 3A: continuous area of gap section 4: servo burst section 5-1, 5-2 ...: servo burst signal Recording section 6-1, 6-2 ...: No signal recording section 7: Head 8-1, 8-2 ...: Head gap I, II, ...: Information recording track

Claims (3)

[Claims] 1. A method for controlling the speed of an information recording medium, comprising:
In the information recording medium, a plurality of information recording tracks in which a data block of a predetermined length and a gap portion are alternately continuous are arranged in parallel and parallel to a traveling direction, and the gap portion over the information recording tracks is The continuous area is provided with a servo burst section in which servo burst signal recording sections and signal non-recording sections are alternately arranged in a direction orthogonal to the traveling direction, and the servo burst extended perpendicular to the traveling direction. The signal recording section is formed with a length of at least twice the arrangement pitch of the information recording tracks, and in the speed control, the servo burst recorded in the servo burst signal recording section of the servo burst section is used. A method for controlling the speed of an information recording medium, comprising using a signal as a clock signal. 2. Using a recording / reproducing head provided with two or more head gaps, positioning at least one of said head gaps in a servo burst signal recording section, and reproducing a waveform obtained from said servo burst signal recording section. 2. The speed control method for an information recording medium according to claim 1, wherein the speed control is performed based on the timing. 3. The length of a servo burst signal recording portion of a servo burst portion on an information recording medium is set to twice the arrangement pitch of information recording tracks, and four head gaps are provided at intervals equal to the arrangement pitch. 3. The speed control method for an information recording medium according to claim 1, wherein the speed control is performed using the recording / reproducing head.