JPH02267701A - Magnetic recording system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording system for magnetic disks, and particularly to improving the recording density thereof.

[Conventional technology]

The conventional recording method on magnetic disks is as follows.
If the rotation speed is kept constant, the recording frequency, that is, the track
It was a method that also kept the record sensitivity to laps constant. The advantage of this method is that it is easy to perform so-called random access, in which information can be retrieved from any location on the disk. An example of this is Japanese Patent Application No. 44-41747.

[“aM” that the invention seeks to solve]

The above conventional technology is not the best method from the viewpoint of recording density. In other words, the R14 recording density is different between the inner and outer circumferences of the disk, and there is a problem in effectively utilizing the area of the disk. Ta.

The purpose of the present invention is to write uniformly over the entire surface of a magnetic disk.
The objective is to provide a magnetic recording method that can achieve high density.

[Means to solve the problem]

In order to achieve the above object, information to be recorded is frequency-converted based on information about the radial position of the track on the disk where the magnetic head is located. By converting the inner periphery to a lower frequency and recording on the outer periphery, that is, the area where the linear velocity due to rotation is large, at a high frequency according to the speed, the linear recording density can be made constant over the entire surface of the disc.

The position information of the magnetic head can be obtained by adding track number information to a tracking signal recorded on the disk in advance, and reading this information with the magnetic head.

Alternatively, this can be realized by adding tracking information in the form of grooves to the disk in advance, recording the track NQ1'l\ information in the form of minute holes, and following these with an optical head that reads them with a light beam.

[Effect]

By knowing the radial position of the magnetic head in advance using the various methods mentioned above, in order to efficiently record at high density there, the frequency of the recorded information increases as the radial position increases. The recording density on the inner and outer peripheries of the disk can be made constant, and as a result, the recording capacity can be increased.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

<Example 1> This will be explained with reference to FIGS. 1, 2, and 3.

In FIG. 1, an example will be explained in which information is recorded using a magnetic head. First, in the case of information recording, a magnetic head 12 is placed on a rotating magnetic disk 11, and the radial position of this head is detected by a scale. On the other hand, the recorded information is frequency-converted according to its radial position so that the linear recording density is the same at any position, and is recorded from the magnetic head to the disk through a recording/reproducing circuit.

This conversion is proportional to the radius, and the frequency increases toward the outer circumference. In the case of reproduction, the information signal obtained by the head is passed through a recording/reproducing circuit, where the frequency is reversely converted in accordance with the radial position where the head is located, and after amplitude correction, it is taken out as a reproduced signal.

Here, the amplitude correction is to correct the difference in signal amplitude obtained from the head between the inner and outer circumferences of the disk. The signal amplitude obtained from the head is 5mV at the outer circumference, but it becomes a small signal of less than 1 mV at the inner circumference, so it is better to make this the same value in all areas and extract it as a reproduced signal. desirable in processing. Here, for example, I M H at a position with a radius of 60 mm
When a signal of z is recorded, the device at a radius of 150 mm has 2.5 Ml (by converting the recording signal frequency in proportion to the radial position so as to record the signal of z, it can be recorded anywhere on the disk. , the linear recording density can be made the same, and the recording capacity per disk can be greatly improved compared to the conventional method.

FIG. 2 shows the concept of a magnetic disk recorded in this manner. That is, the width d and pitch P of the recorded information 21 are recorded in the same way on the inner and outer circumferences, and the same linear recording density can be achieved on the inner and outer circumferences.

Here, as another example of the scale, the moving distance of the head is measured using the grooves of the diffraction grating as a reference. Or optical interferometer 81
A possible method is to use +1 to measure the distance traveled by the head.

Further, an example in which a clock signal recorded in advance on a magnetic disk is used instead of a scale will be described below. FIG. 3 shows a cross-sectional structure of a disk containing clock information.

A first recording film 32 for recording the previous clock signal on a magnetic disk substrate 31 made of aluminum, a second recording film 33 for recording information on top of the first recording film 32, and a recording film 32 for recording information on top of the magnetic disk substrate 31, and a recording film 32 for recording information from the collision of the magnetic head as the top layer. Anti-sliding film 34.
It has a structure in which a lubricating film (not shown) is laminated. Here, the first recording film 32 and the second recording film 33 have different magnetic properties to prevent erroneous recording and reproduction due to interference between them.

The magnetic head first reads the clock information, converts the frequency of the information to be recorded or reproduced at that position, and then records or reproduces the information. This enables linear recording in the same way without the need for a scale. Density can be kept constant.

FIG. 4 shows an outline of the disk surface of this embodiment.

There is an information area 42 after the clock area 41, and the physical size of the data recorded on the inner and outer peripheries is the same.

FIG. 5 shows a comparison of recording densities between the conventional method and the present method. In the conventional method, the recording density decreases toward the outer periphery, whereas in this method, the value remains constant regardless of the recording radius, indicating that the recording capacity per disc is large. . The same thing can be said about the recording capacity per revolution of the disk shown in FIG. 6, which shows that the present system has a large recording capacity.

<Example 2> A second example is shown in FIG. 7. This example has two types of uneven patterns 77 on the surface of a magnetic disk substrate 71, and a magnetic recording film 72 is formed thereon. Guide track 73. This means track Nα information 74, and this portion is followed by a composite head that is an integrated optical head 75 and magnetic head 76. Applying optical disc technology, the optical head follows the track and tracks Nα
After reading and detecting a predetermined position, the data is converted to a frequency corresponding to the radial position, and after recording in the data area with a magnetic head or reading the recorded data, inverse frequency conversion is performed.

In addition to the embodiments described above, as an example of the magnetic head position detection scale, the moving distance is measured by optical interferometry.

It is also possible to detect the head position by applying a method such as measuring the moving distance by changing the electric capacitance or using an electronic micrometer.

〔Effect of the invention〕

According to the present invention, by changing the recording frequency depending on the position of the magnetic head and keeping the recording linear density in the circumferential direction of the disk always constant, it is possible to increase the storage capacity on the negative magnetic disk.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a magnetic recording system according to an embodiment of the present invention, FIG. 2 is a plan view showing a magnetic disk according to the present invention, and FIG. 3 is a cross-sectional structure of a magnetic disk according to an embodiment of the present invention. 4 is a plan view of a disk of an embodiment using a disk with a built-in clock signal, FIGS. 5 and 6 are graphs showing the effects of the present invention, and FIG. 7 is a tracking system of a disk of an embodiment having a concave-convex pattern track. FIG. 11... Magnetic disk, 12... Magnetic head, 21
... Recording information, 31... Substrate, 32... First recording film, 33... Second recording film, 34... Scratch-resistant film,
41... Clock area, 42... Information area, 73
...Guide track, 74...Track Nα information,
75... Optical head, 76... Magnetic head. Early drawing graduation drawing first flash. Sword No. ■ -′+'+'t- No. Σ 1,000'g

Claims (1)

[Claims] 1. A rotating circular magnetic disk with a magnetic recording film, and a magnetic head for writing or reproducing information thereon;
A magnetic recording system comprising means for detecting the position of the magnetic head, characterized in that the number of rotations of the disk is fixed and the linear recording density is constant. 2. A magnetic recording method according to claim 1, characterized in that, as a method of keeping the linear recording density constant, the recording frequency is changed in accordance with the recording radius. 3. In the magnetic recording system according to claims 1 and 2, as means for detecting the position of the magnetic head,
A magnetic recording method that uses track information pre-recorded on the disk. 4. In the magnetic recording system according to claims 1 and 2, as means for detecting the position of the magnetic head,
A magnetic recording method characterized by optical detection using grooves carved into a diffraction grating. 5. A magnetic recording system according to claims 1 and 2, characterized in that optical interference is used as means for detecting the position of the magnetic head. 6. A rotating circular magnetic disk with a magnetic recording film and a magnetic head for writing or reproducing information thereon;
In a magnetic disk device consisting of a composite head integrated with an optical head that causes the magnetic head to follow a guide track prepared in advance on a disk, the number of rotations of the disk is fixed and the linear recording density is made constant. Features magnetic recording method.