JPH04182901A - Magnetic recording system - Google Patents

Abstract

PURPOSE:To prevent the higher harmonic components of servo signals written at low frequencies from being superposed on a data signal and from degrading S/N by setting the azimuth of the servo signals used for positioning a magnetic head in a deep layer part at 10 deg. with respect to the data signal in a front layer part and recording the servo signals. CONSTITUTION:A magnetic recording medium 1 is formed with the deep layer part of the magnetic layer formed on a base file 5 as a servo signal layer 3 and the front layer part as a data signal layer 2. The servo signals 3a, 3b are recorded on the servo signal layer 3 and the data signal 2a is recorded on the data signal layer 2. The servo signals 3a, 3b are so recorded as to have the azimuth theta with respect to the data signal 2a. The higher harmonic components of the servo signals 3a, 3b written at the low frequencies are suppressed by the inclination loss of the magnetic head if the reading out of the data signal 2a is executed in this state. The practicably effective value of theta is >=10 deg.. The superposing of the higher harmonic components of the servo signals is decreased in this way at the time of the reading out of the data signal and the S/N of the data signal is improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to a so-called deep servo method in which data signals are recorded in the surface layer of a magnetic recording medium and servo signals used for positioning a magnetic head are recorded in the deep layer. Concerning magnetic recording methods.

[Conventional technology]

In recent years, the storage capacity of magnetic recording devices has been increasing, and two methods have been adopted to increase the capacity: increasing linear recording density and increasing track density. Both of these methods have been adopted to increase the capacity of floppy disk devices, which are a type of magnetic recording device, but among these, especially for those whose storage capacity exceeds 10)4B due to improved track density, some kind of servo drive is used. It is said that closed-loop positioning control of the magnetic head using a method is required.

Servo systems currently used in large-capacity floppy disk drives for this purpose include sector servo systems and deep servo (Embedded Servo) systems, but in order to further increase capacity, high positioning accuracy is required. It is said that the deep servo method is advantageous because it can obtain the following.

FIG. 2 is a sectional view showing an example of a magnetic recording medium using the conventional deep servo method as described above.

In the example shown in FIG. 2, the deep part of the magnetic layer formed on the base film 8 is used as the servo signal layer 7, the surface part is used as the data signal layer 6, servo signals are recorded on the servo signal layer 7, and the data signal layer Data signals are recorded on the magnetic head 6 and read out by a magnetic head 9.

FIG. 3 is a sectional view showing another example of a conventional deep servo type magnetic recording medium.

In the example of FIG. 3, the deep part of the magnetic layer formed on the base film 13 is the servo signal layer 12, the surface part is the data signal layer 10, and the servo signal layer 12 and the data signal layer 1
A guard hand layer 11 is provided which is subjected to direct current magnetization (no signal is recorded) during zero. Gart band layer 11
uses the separation loss caused by widening the magnetic head 14 and the servo signal layer 12 to reduce the S/N ratio caused by harmonic components of the servo signal written at low frequency interfering with the data signal. Prevent the ratio from deteriorating.

[Problem to be solved by the invention]

In the case of the conventional deep servo magnetic recording method described above, as shown in the example of FIG. This has the disadvantage of worsening the /N ratio.

On the other hand, in the case shown in the example shown in Fig. 3, the above drawback is solved by the separation loss for the servo signal that is generated by providing a guard band layer, but it takes time to erase only the guard band layer. However, when recording a data signal, the guard band layer subjected to DC erasure acts as a DC bias magnetic field, resulting in a peak shift when writing the data signal.

[Means to solve the problem]

The magnetic recording method of the present invention is a deep servo magnetic recording method in which a data signal is recorded in the surface layer of a magnetic recording medium and a servo signal used for positioning a magnetic head is recorded in the deep layer. The method includes recording the servo signal with a signal azimuth difference of 10 minutes or more.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are a plan view and a sectional view showing an example of a magnetic recording medium to which the present invention is applied.

In FIG. 1, a magnetic recording medium 1 includes a base film 5
The deep layer of the magnetic layer formed above is used as a servo signal layer 3, the surface layer is used as a data signal layer 2, servo signals 3a and 3b are recorded on the servo signal layer 3, and data signal 2a is recorded on the data signal layer 2. are doing. Servo signals 3a and 3
b is recorded so as to have an azimuth θ with respect to the data signal 2a. This can be achieved by tilting the magnetic head of the servo signal writing device by an angle θ and writing the servo signal thereby.

A magnetic head for writing and reading data signals is provided in parallel with the data signal 2a.

When data signals are read in this state, harmonic components of the servo signals written at low frequencies are suppressed by the tilt loss of the magnetic head. In the design example, in the case of θ-20", the harmonic component of the servo signal superimposed on the data signal is reduced by about 20 dB compared to θ-0°, and the reduction in the servo signal at this time is about 0.5 dB. A practically effective value of θ is 10° or more.

〔Effect of the invention〕

As explained above, the magnetic recording method of the present invention provides an appropriate azimuth of 7I to the servo signal recorded in the deep servo signal layer, thereby reducing the harmonic components of the servo signal when reading the data signal. The effect is that the superposition can be significantly reduced, and therefore the S/
This has the effect of improving the N ratio. Furthermore, since it is not necessary to provide a guard band layer between the servo signal layer and the data signal layer, there is also the effect that the time for recording servo signals can be shortened. Furthermore, there is also the effect that peak shifts do not occur when writing data signals.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are a plan view and a sectional view showing an example of a magnetic recording medium to which an embodiment of the present invention is applied;
The figure is a sectional view showing an example of a magnetic recording medium using the conventional deep servo method, and FIG. 3 is a sectional view showing another example of the magnetic recording medium using the conventional deep servo method. 1... Magnetic recording medium, 2, 6, 10...
・Data signal layer, 3, 7, 12... Servo signal layer, 5, 8, 13... Base film, 9, 1
4...Magnetic head, 11...Gart band layer.

Claims (1)

[Claims] In a deep servo magnetic recording system in which a data signal is recorded in a surface layer of a magnetic recording medium and a servo signal used for positioning a magnetic head is recorded in a deep layer, the azimuth of the servo signal with respect to the data signal is set to be 10 degrees or more. A magnetic recording method comprising recording the servo signal.