JPH02308404A - Magnetic disk recording system - Google Patents

Abstract

PURPOSE:To constitute the subject system so that information can be read without an error at the time of densification by writing a prescribed number of specific patterns whose bit shift becomes maximum subsequently to a pre scribed number of signals of a prescribed interval in a sink area in a recording format. CONSTITUTION:A GAP part 1 is an area for absorbing an uneven rotation of a medium and exists between an ID part 2 and a data part 3. In the ID part 2, information corresponding to a name plate of the next data part 3 is written. A sink area 4 is written in the ID part 2 and the beginning of the data part 3, and allows a synchronizing circuit to generate easily a sampling clock signal for fitting a frequency and a phase to a signal of the ID part 2 or the data part 3 written in a magnetic recording medium. In the sink area 4, in the beginning, '00' or '11' signal is written continuously, and thereafter, a pattern of '110110' is written repeatedly. In such a way, by writing a prescribed number of specific patterns whose bit shift becomes maximum subsequently to a prescribed number of signals of a prescribed interval in the sink area 14, information can be read without an error at the time of densification.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording method on a magnetic disk, and particularly to a formatting method in perpendicular magnetic recording.

[Conventional technology]

Conventionally, in the pull-in signal area (hereinafter referred to as sync signal) used in magnetic recording, either the minimum bit sequence or the maximum bit interval used in the data area is written, and a synchronization circuit (hereinafter referred to as VF○) is written. was tuned to the data frequency and in phase with the data in this region.

[Problem to be solved by the invention]

However, since these sync bytes are written at the same frequency, it is easy for the VFO to synchronize, but it is not possible to judge the quality of the data.Especially in the case of perpendicular magnetic recording, the peak shift of the read data is due to the characteristics of the medium. significantly influenced.

This is due to the interaction between the characteristics of the medium and the magnetic head used for reading, and it is necessary to make corrections on the reading circuit side. However, as described above, it was not possible to determine how to perform correction using the sync signal in the conventional format.

[Failure to solve the problem]

The present invention first writes a certain number of sync signals at the same bit interval (which may be the minimum or maximum of the data bits used), completes the VFO pull-in in this written area, and then continues to use it. A format is provided in which this area can be used to adjust the phase relationship between the VFO synchronization signal and the read data by alternately writing a fixed number of data with the minimum bit interval and the maximum bit interval of data bits. It is.

That is, the present invention provides a signal with a fixed number of bit intervals in a sync area to facilitate synchronization with a phase synchronization circuit that generates a sampling clock synchronized with a read signal in a recording format written on a magnetic disk medium. This is a magnetic disk recording method characterized by alternately writing a fixed number of signals with the maximum bit interval and the minimum bit interval of the data bit intervals used subsequently, or writing a fixed number of specific patterns.

〔Example〕

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

First, the recording format of the medium and the contents of the sync area of the conventional medium will be explained with reference to FIGS. 2 and 3. In Figure 2, GA
PI is an area for absorbing rotational unevenness of the medium and is 10 parts 2
and data section 3, between data section 3 and 10 section 2. 10
In part 2, information corresponding to the name tag in the next data part 3 is written. The data section 3 is so-called information. Sink area 4 is written at the beginning of 10 part 2 and data part 3, and VF
This is to make it easier for the O circuit to generate a sampling clock signal that matches the frequency and phase of the signal of the data section 2 or data section 3 written on the magnetic recording medium. Conventionally, the contents of the sink area 4 are a1βI as shown in FIG.
I OII or aI A II I If was written.

FIG. 1 shows the sink area 14 of the present invention. The figure is MF
It is written about the M recording method. In this invention, first the II OOIT or IT 11 II times signal is written continuously, and then the pattern "110110" is written repeatedly.

FIG. 5 shows a conventional read signal in the sink area. In this signal, the medium is almost a sine wave at high density,
It is difficult to distinguish them regardless of the magnetic head.

FIG. 4 shows II 00 II in the sink area of the present invention.
Or ' l 1 '' pattern followed by < ”
This shows the read wave number waveform near the switching of the 110" pattern. With this method, after the VFO synchronizes with the read signal, it is possible to predict the peak shift of the signal written in the data section or ID section that follows after the VFO synchronizes with the read signal. It is possible to adjust the readout circuit within this region so that the phases match by using the VFO sampling clock synchronized with the VFO.

〔Effect of the invention〕

As explained above, the present invention writes a certain number of specific patterns that maximize the bit shift following a certain number of signals at certain intervals in the sink area of the recording format, thereby increasing information density. This has the effect of allowing you to read without errors.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the recording format repo to the sync area according to an embodiment of the present invention, FIG. 2 is a diagram showing the recording method to the medium, and FIG.
Figure 4 showing the recording format in the sink area according to the conventional example
This figure is a waveform diagram of the read signal in the sink area of FIG. 1, and FIG. 5 is a waveform diagram of the read signal in the sink area of FIG. 3. 1...GAP section, 2...ID section, 3.
...Data area, 414...Sink area Attorney Susumu Uchihara 1 Figure 2HIIIOIIOIlo Figure 4

Claims (1)

[Claims] A predetermined number of pull-in signals are written at the same bit interval in a recording area for recording the format of a magnetic recording medium to facilitate synchronization with a synchronization circuit that generates a sampling clock signal synchronized with a read signal. Magnetism characterized by writing a predetermined number of signals with the maximum bit interval and minimum bit interval used in the data area alternately after the pull-in signal, or writing a predetermined number of specific patterns that maximize the bit shift. Desk recording method.