JPS6069801A - Magnetic disc recording system - Google Patents

Abstract

PURPOSE:To make high-density recording possible by making respective magnetization directions of adjacent tracks nonparallel with each other and utilizing the inclination loss effect of a gap to eliminate the crosstalk which is caused when tracks are recorded close adjacently to one another. CONSTITUTION:An annular recording track band 3 is formed in the outside circumferential part near the circumferential edge on a magnetic disc 1 rotated around a rotation center O. A guard band is not formed between a recording track A and a recording track B adjacent to each other, and they are recorded close adjacently to each other. A magnetic head having a gap which intersects obliquely the radial direction of the magnetic disc, and thereby, the recording direction intersect obliquely the direction orthogonal to the breadthwise direction of tracks. That is, tracks A and B are so recorded that respective magnetization direction are not parallel with each other. Consequently, information on the adjacent track B does not interfere with information of the track B when information of the track A is reproduced; and even if it interferes with information of the track A, this interference appears as only a weak signal related to cosine components of the angle made between respective magnetization directions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a magnetic disk recording system capable of recording information at high density.

[Background 1] Conventionally, in magnetic disks, guard bands are generally provided between trunks in order to prevent crosstalk in which signals are detected from adjacent trunks and interfere with each other. Is it possible to narrow the width of the guard band to record information with high density in a limited recording area?
The reliability of the system has fallen to the bottom. If it is a simple r, IJ, r (IJ differential 41) signal, some crosstalk can be covered by devising a signal processing circuit.However, for example, with analog signals such as video information, crosstalk is '1 report (reproduced image) is significantly adversely affected.

On the other hand, recently developed electronic still cameras use ultra-small magnetic disks with a diameter of about 5c+n. In this type of ultra-small magnetic disk, since the curvature of the imprint track is large, the area in which recording is possible is inevitably limited to the vicinity of the outer periphery of the disk. 1 rank density is severely restricted. For example, in the case of a prototype electronic still camera (product name 1-Mabica 1; manufactured by Sony Corporation), one track and one frame is 5.
The maximum number of frames that can be recorded is 0 frames, and in response to the desire to increase the number of frames recorded, a new high-density recording iJ technology has been developed.

[Object of the Invention] Therefore, the main object of the present invention is to provide a magnetic disk recording method that allows information to be written with high density in a limited recording area of a magnetic disk.

An object of the present invention is to increase the recording density of magnetic disks, particularly ultra-small magnetic disks for recording analog signals, so that, for example, the number of frames recorded in electronic still cameras can be increased.

[Summary of the Invention 1 For this reason, the present invention provides at least one magnetic head having a camp oblique to the radial direction of a rotating magnetic disk, so that the respective magnetization directions in adjacent trunks are non-parallel, and the trunks are closely adjacent to each other. However, by eliminating the guard band, the crosstalk that becomes noticeable is divided by 7I using the gradient loss effect of the gap, thereby making high-density recording possible.

Hereinafter, the present invention will be specifically explained with reference to embodiments shown in the accompanying drawings together with other features.

[Example 1] Rotation 111j around the rotation center C) as shown in FIG.
:The magnetic disk 11 has an outer circumference t that is one inch closer to the periphery.
A plurality of recording tracks 2 are formed, and a circular recording rank band 3 is formed.

As shown in FIG. 2, which is an enlarged view of the PQ section in FIG. 3. Record the image 'L'j +, lj2. jr, as an example, the horizontal synchronization signal is 1J, 5I.
I.A.

To represent H13, 1st 4th tangent 1 rank A, l
'=, the recording directions are oblique to each other in a direction perpendicular to the width of the trunk. In other words, the magnetization direction of trunk A (two directions perpendicular to horizontal synchronization signal recording section HA) and the magnetization direction of track "3" (horizontal synchronization signal recording section 1
-I 131 orthogonal) J direction) or J! 'lt4
It is recorded that

Therefore, when generating the information of track A, there is no interference with the information of the adjacent trunk 13, or even if there is Ilj, there is only a weak signal related to the cosine component of the angle formed by the mutual magnetization directions. That is, crosstalk is substantially suppressed by using the slope loss effect. As a result, compared to the conventional example in which a guard band was formed, the recordable area was expanded by the area related to the guard band, and high-density recording became possible.

FIG. 3 shows a recording/reproducing magnetic head suitable for applying the above recording method.

A magnetic head 8 indicated by reference numeral 4 and a magnetic head B indicated by reference numeral 5 are integrally formed with a head separation band 6 interposed therebetween. A camp 4g is formed on the head +'+ij surface 7 of the magnetic head A (4) that forms a sliding part with the magnetic disk 1, and a camp 4g is formed on the head surface 8 of the magnetic head B (5).
A cap 5g is formed on the holder. Each gap 4[+5g is formed so as to be inclined with respect to the thickness direction of the magnetic head 1.5. The length of the gap 4g + jg in the thickness direction of the magnetic head, or the recording trunk 2 (@2
Corresponds to the track width in Figure). Integrated magnetic head 4
5 is installed perpendicularly to the disk surface of the magnetic disk 1 and is movable in the radial direction of the magnetic disk 1, and its movement is controlled by 'ζ based on a predetermined control signal.

In addition to the integrated magnetic head shown in FIG. 3, separate magnetic heads having different gap inclination angles may be provided. Also, different ki? The number of magnetic heads having a 7' angle of inclination is not limited to two, but a plurality of 2 V/2 magnetic heads may be provided. Furthermore, it is also possible to provide a 71.degree. structure in which sogzag camps (as many as the number of tracks) are formed over the entire width of the recording track band. In this case, the activating cap can be electronically controlled and no control system is required for moving the magnetic head. In addition, the third
The difference in gaps 4g and 5g related to the magnetic head is as follows.
As shown in Figure 1, adjacent tracks 13. A, rotational direction of the magnetic disk R1:
The positional relationship may be as shown in a), or the caps may be oriented counterclockwise to each other with respect to the radial direction of the disk, as shown in (I) of the same figure. In addition, the same figure (c) ~
As shown in (f), the cap of one magnetic head may be arranged in the radial direction of the disk. In both cases, the magnetic field has a gap oblique to the radial direction of the magnetic disk.

At least one track is provided, and the respective magnetization directions in adjacent tracks are non-parallel (the magnetization directions are perpendicular to the gap).

Next, FIG. 4 schematically shows a recording/reproducing circuit using the above magnetic head.

10 is a microcomputer equipped with an input/output section, and recording data to be recorded on the magnetic disk 1 is first inputted to this microcomputer.

Input data is subjected to FM modulation, MFM modulation, or NRZ modulation by the modulator 11. The modulated signal is amplified by the recording amplifier 12, applied to the magnetic head (-i, 5) via the switcher 13, and written to a predetermined track/reference of the magnetic disk 1. At this time, the magnetic head V
4.5 may be activated at the same time, or only one of them may be activated. The microcomputer 10 controls whether data is written twice (overwritten) or written twice. In addition, the control signal for shifting the phase of a specific signal at the time of re-entry and for tracking is also transmitted from the microcomputer to the servo amplifier 15 of the disk drive motor 1 and the tracking amplifier 16. commanded.

The re-4 signal read by the magnetic node 4 or 5 is
The signal is input to a regenerative amplifier 17 via a switcher 13.

The amplified signal is demodulated by the demodulator 18, and outputted as reproduced data to external equipment via the microcomputer 1(). In this example, the recording method described in "-" is adopted, so
There is almost no crosstalk effect on the reproduced data. For example, when a still image is recorded on the magnetic disk 1, when pure light is emitted and the still image is viewed on a color television receiver, there is little noise and the outline of the object is clear.6 This record is shown in Figure 6. An electronic still camera suitable for applying the method is shown. An image is received by a CCI chimp 21, which is a solid-state image sensor, through a VTR camera lens 20. The magnetic disk 22 on which image signals are recorded is housed in a pack with a window 23 open. During recording, the magnetic disk 22 is rotated at a predetermined speed by a motor, and the magnetic disk 24 is rotated by a motor at a predetermined speed to generate images on two concentric tracks of the disk (one side). Record the signal. In Fig. 6, 25 is the 7-eye ring, and 26.27 is the finder mirror.

28 is a camera structure, 29 is a self-timer, 30 is a release button, 31 is a mode switcher, 32 is a battery,
33 is a video circuit, and 34 is a camera circuit section.

[Effects of the Invention 1] As described in 2 above, the present invention is a recording method in which the trunks and trunks are recorded adjacent to each other, but the magnetization directions of the adjacent trunks are made non-parallel to suppress crosstalk. ,
By applying this recording method to magnetic disks regardless of diameter, and ultra-small magnetic disks with restrictions on the nfl area, information storage can be increased beyond the conventional recording density of guard band formation. For example, in an electronic still camera, the frame rate can be significantly improved from 50 frames to 70 frames.
This has the advantage of allowing up to 100 frames to be photographed.

[Brief explanation of drawings]

FIG. 1 is a pattern diagram showing the recording area of a magnetic disk according to an embodiment of the present invention, FIG. 2 is an enlarged view of the PQ section of FIG. 1, and FIG. 3 is an example of application of the embodiment of the present invention. Perspective view of IS in magnetic field, Figure 5 shows an example of a pond with an angle of inclination between two gaps. "a-tsuku circuit diagram, 6th
The figure is a perspective view of an electronic still camera suitable for applying the present recording method. ]...Magnetic disk, 2...IJ, trunk, j (...5 city I trunk (ishi, A
+B...1 rank of 1 insect contact, 1,5...
Magnetism, 48+! '))i...Magnetism-/
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Claims (1)

[Claims] (1) In a magnetic disk recording method in which information is recorded on a rotating magnetic disk using a magnetic head, at least one magnetic head having a gap diagonal to the radial direction of the magnetic disk is provided, and each magnetization direction in an adjacent trunk is A magnetic disk recording method characterized by non-parallel tracks and closely adjacent tracks.