JPS5894136A - Magnetic transferring recorder - Google Patents

Abstract

PURPOSE:To record a signal with its unevennesses whose dimensions in both directions of the width of the track and the wavelength coincide with a magnetized pattern in a magnetic recording and reproducing device, by irradiating a laser beam upon a magnetic layer through a special optical system. CONSTITUTION:A laser beam from a laser oscillator 11 is irradiated, after the laser beam is modulated by an optical modulator 12 in accordance with a signal 13 to be recorded, upon a magnetic layer 3 or a non-magnetic layer, on which the magnetic layer is to be formed, of a magnetic recording medium 1 through an optical system containing a cylindrical lens 15 and an optical filter 14 which evens the strength distribution of the laser beam at least in the direction of the width of the track on the magnetic layer 3 or the non-magnetic layer within the width of the track, and an unevenness is formed according to the signal 13. The magnetic recording medium 1, on which the signal 13 is recorded by the unevenness, is used as a medium for transferring the recorded information to other magnetic recording media by impressing the magnetic field upon the other media while the medium 1 is in contacted with the other media.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an apparatus for magnetically transferring a signal t@2 recorded on a first magnetic recording medium in the form of unevenness to a magnetic recording medium, and particularly to The present invention relates to a means for forming unevenness in a magnetic recording medium C:.

The technical backbone of the invention is a method for recording and reproducing video signals, audio signals, etc. on a magnetic recording medium using a melting point magnetic head.

Although it is currently widely used, it is not necessarily sufficient in terms of recording density χ and 8/N.

In contrast, in recent years, laser beams or electron beams have been used to record signals in the form of convexes and convexes, and mechanical methods have been developed.

Also, video discs that can be reproduced electrostatically or optically are being actively developed and have already reached the stage of practical use. According to recent laser beam processing technology, it is possible to easily form irregularities on the order of submigron.
/N recording and playback can be performed. However, such video disks require special playback devices to play back the unrecorded signal Y, and these are more expensive than the magnetic recording and playback devices that have been used in the past.

In order to solve problems 1 with such conventional video discs, etc., the inventors recorded signals in the form of concavities and convexities on a first magnetic recording medium. A method V is proposed in which a signal recorded on a first magnetic recording medium is magnetically transferred to a second magnetic recording medium by applying a magnetic field to these 1.s2 magnetic recording media by bringing the medium into contact with the medium. (Japanese Patent Application No. 54-82609, etc.). According to this method, unevenness can be formed on the submicron order according to the signal recorded on the first magnetic recording medium, so it is possible to form irregularities on the submicron order. The recording density of the recorded signals is also extremely high, and since the signal recording method in @2's magnetic recording medium itself is magnetic, in principle, the reproduction should be performed using a conventional magnetic recording and reproducing device. is possible.

By the way, the recording pattern, that is, the magnetization pattern on the magnetic recording medium in the conventional magnetic recording Nti device CN is different from the recording pattern due to unevenness on a video disk, for example! For example, in a VTR of this type, approximately α8μ in the wavelength direction.
m,) It has an elongated pattern of about 29.2 μm in the rack width direction. Therefore, the device must be designed to most efficiently reproduce such magnetization patterns!
Considering this, it is desirable that the magnetization pattern of the signal transferred and recorded on the second magnetic recording medium is also an elongated pattern similar to the magnetization pattern in the normal magnetic system. The unevenness corresponding to the signal recorded on the magnetic recording medium @l also needs to be an elongated pattern similar to the magnetization pattern described above.

Therefore, the inventors have proposed a magnetic transfer recording*t that can be formed on the first magnetic recording medium with the above-mentioned elongated concavo-convex pattern, or a non-fiber layer on which this magnetic layer is formed. We have already proposed a device in which elongated irregularities are formed by irradiating a magnetic layer with a laser beam modulated by a recording T signal, which is converted into an elongated circular beam using a ν-lindracal lens. ing(
(Japanese Patent Application No. 56-42910).

However, there is no problem with this method if the intensity distribution of the laser beam is flat, but in reality, the intensity distribution of the laser beams -f and -A is not flat, so even though the shape of the unevenness is generally an elongated pattern, , its dimensions in the track width direction g and in the wavelength direction are difficult to match with those of the magnetization pattern in the magnetic recording/reproducing device. Because the power in the center is strong, the width of the unevenness formed by this is not the same in the wavelength direction at the center in the track width direction and at both ends in the track width direction, and this is different from that of the magnetization pattern in the magnetic recording/reproducing apparatus 1:. It is very difficult to match.

OBJECT OF THE INVENTION The object of this invention is that I! A magnetic transfer recording device capable of recording signals on a magnetic layer of a magnetic recording medium by using a laser beam as unevenness whose dimensions in both the track width direction g and the wavelength direction match those of a magnetization pattern in a magnetic recording and reproducing device. It is to provide the following.

Summary of the Invention This invention provides a magnetic layer of a first magnetic recording medium or a non-magnetic layer C on which this magnetic layer is formed: a 1 kV lintrical lens with a laser beam modulated by a signal to be recorded;
The laser beam is irradiated through an optical system including an optical filter that flattens the intensity distribution in at least the track width direction on the magnetic layer or the nonmagnetic layer at least with a track width of 4, and the signal is The unevenness is formed according to the shape! It is a feature.

Embodiment of the Invention The first factor is the transfer process in an embodiment of this invention! In the figure, l is a magnetic recording medium IIl having a magnetic layer 1v on which signals are recorded in an uneven form on a base layer z, and 4 is a flat magnetic layer #Y on a base layer 5. Set it up! This is the second magnetic recording medium.

At the time of transfer recording, the surface flv of the ζ binary material layer of the magnetic material layer I is brought into contact with the surface flv, and the magnets 7 and 81 are placed between different magnetic poles with these first and second magnetic recording media 1.4f in between. are placed so that they face each other, and a DC magnetic field is applied in the thickness direction. and,! $1. M2 magnetic recording medium 1'm4 is placed in the track direction f1.8 with respect to the magnet 7.8. Move lOc relative sea. In this way, the magnetic layer 6 of the second magnetic recording medium 4 is magnetized with a varying strength depending on the unevenness of the magnetic layer 3 of the magnetic recording medium l of jll. That is, a magnetization pattern corresponding to the unevenness of the magnetic layer 1 is formed on the magnetic layer 1, and magnetic transfer recording is performed.

In this case, the magnetic layer 6 of the second magnetic recording medium 4 is uniformly magnetized in advance with a magnetic field in the opposite direction to the magnetic field generated by the magnet 1.8.
At the time of transfer recording, the direction of magnetization of the magnetic layer 1 may be reversed depending on the unevenness of the magnetic layer 1 of the magnetic recording medium L.

Note that this transfer process can be modified in various ways. For example, the magnetic field for transfer may be an alternating current magnetic field or a composite magnetic field of direct current and alternating current magnetic fields, and the direction of application may also be in the planar direction or both the thickness direction and the planar direction. But that's okay, Sara Cl!
! It is also possible to increase the transfer efficiency by magnetizing the magnetic layer 1v of the magnetic recording medium 1 in advance.

Figure 82 shows a signal to the first magnetic recording medium l! This figure shows the configuration of an apparatus for recording in the form of unevenness. Note that the laser beam explained in this example is as follows.

TEM-Tru with Yuko. In Figure 2, the radar oscillator 1
The radar beam output from 1 is optically modulated @1! The intensity of the laser beam changes according to the signal 11 to be recorded (that is, the signal 1g, which is modulated by two).

The Rade beam thus modulated by the optical modulator 12 is first turned into a laser beam with a flat intensity distribution in the diameter direction by an optical filter 14 having a predetermined transmission characteristic in which the transmittance varies depending on the position.

The laser beam transmitted through this optical filter 141 is converted from a circular beam to an extremely circular beam by a semi-cylindrical V-one trigonal lens 15≦2, and then condensed by a condensing lens Jig, as indicated by an arrow 11. IJI moving relatively in the direction
Magnetic layer 1g of magnetic recording medium 1: irradiated. As a result of this, irregularities corresponding to the signal 11 are formed on the magnetic layer 3.

Figures 3(a) and 3(b) are views of the lens system vV linear lens 15 in Figure 82 as viewed from the direction S parallel to the cylindrical surface and from the direction perpendicular to this, respectively, and the focal point of this lens system is the cylindrical lens 15. In the direction parallel to the cylindrical surface of 15, P.

In the orthogonal direction, P is farther than Pl. djA perpendicular to the optical axis of the lens system and passing through PBmPH'l respectively
, B, the laser beam will have an elongated shape. Therefore, by placing the first magnetic recording medium 1%' near surface A or surface B, elongated unevenness Y is formed on the magnetic layer 1. I can do T. However, since the major axis direction of the beam differs by 90° between the vicinity of the surface A and the vicinity of the plane B, it is necessary to change the moving direction of the first magnetic recording medium l depending on the major axis direction of the beam.

Next, the structure and operation of the optical filter will be explained using FIGS. 4 to 6.

The intensity distribution in the diameter direction of the laser beam output from the Rade oscillator 11 is, for example, a backlash 1 distribution as shown in Figure 4 (a). are doing. When the laser beam with this glass distribution is irradiated onto magnetic material #1 to form unevenness, the width of the unevenness in the wavelength direction at the center in the track width direction becomes wider as described above.
When this laser beam is passed through an optical filter 4 showing a gas distribution such that the transmission characteristics, that is, the transmittance decreases in the center and increases outward in the diametrical direction, as shown in Figure I, Figure $4 (b
) as shown in the diametric direction FiiJ (bi-isotropically flat intensity distribution. In other words, the intensity distribution is flat within the track width not only in the wavelength direction but also in the track width direction. As a result, the unevenness formed on the magnetic layer 1 has a constant width in the wavelength direction no matter where it is located in the track width direction.
Magnetization pattern at tl
It becomes possible to form. @6 The reason is optical filter 1
-flj'i' of the specific configuration of No. 4 is shown, and in this example, a disc-shaped C: is formed.

It is assumed that the transmittance is minimum at the center and increases outward.

Note that the intensity distribution Y of the laser beam, at which intensity level it should be flattened, depends on the material of the magnetic layer 3σ) of the first magnetic recording medium l on which the unevenness is formed and the magnetic pattern track of the magnetic recording/reproducing device. Irregularities that should match the width dimension (
7)) Depending on the rack width direction, the optical filter 1
4σ) transmittance and focal length of the cylindrical lens 15.

The position of the $1 magnetic recording medium l on the optical axis of the lens system! You just have to choose appropriately.

This invention can be implemented in various modifications, for example, in the above embodiment, the optical filter 14 is placed in front of the cylindrical lens 15, and the force l is placed between the cylindrical lens 15 and the condenser lens 16.

Alternatively, it may be placed between the condenser lens 11 and the first magnetic recording medium l.

Further, in the above embodiment, an optical filter 14 whose transmittance changes T so as to exhibit a Gaussian distribution in an isodirection from the center is used to flatten the intensity distribution in the diametrical direction of the laser beam in an isodirection. .

The intensity distribution of the laser beam in the wavelength direction does not necessarily have to be flattened. That is, as mentioned above, the magnetization pattern in the conventional magnetic recording/reproducing device is 1, for example, V of the β method.
In the case of TR, it has an elongated pattern of approximately 0.8 μm in the wavelength direction and approximately 29.2 μm in the rack width direction.
If the optical system Y needle is set so that the condensing width of the laser beam in the wavelength direction is, for example, 0.8 μm or less, the wavelength direction of the unevenness is determined as shown in Fig. 7 (a) and (b). Using an optical filter whose transmittance shows a Gaussian distribution only in the direction, but whose transmittance is constant in the wavelength direction!

Laser beam intensity distribution t-1118 diagram (1) # (
b) As shown in C, it may be flat only in the track width direction and remain Gaussian distributed in the wavelength direction.
This is a specific configuration example of the transmission filter shown in the figure, which is formed into a rectangular plate shape, and in the long side direction (track width direction) gl, the transmittance is minimum at the center, increases outward, and increases in the short side direction. (Wavelength direction) The transmittance is constant in yz.

Further, it goes without saying that the second magnetic recording medium of the present invention may be in any form of disk, sheet, or tape.

Furthermore, in the above example, the magnetic layer of the $1 magnetic recording medium was directly irradiated with the laser beam Y to form the unevenness L, but it was also possible to form the unevenness L by directly irradiating the magnetic layer of the $1 magnetic recording medium. Irradiate the substrate with laser light to create irregularities!
After forming the above-mentioned non-magnetic layer &: chemical treatment such as steaming, the magnetic layer is formed! Forming the first magnetic recording medium! You may get it.

As described in detail, according to the present invention, the magnetic layer of the @l magnetic recording medium is coated with 4M to make the size of the elongated unevenness in the wavelength direction in the track width direction uniform by 3 in the track width direction. Because you can.

Traditional magnetic recording! It is possible to easily match the magnetization pattern applied to the W generator with the dimensions of the unevenness in both the track width direction and the wavelength direction.

This makes it possible to transfer and record the two signals as an elongated magnetization pattern on the second magnetic recording medium. The effect of efficiently reproducing data as it is can be obtained.Furthermore, in the present invention, a laser beam is irradiated onto the magnetic layer or non-magnetic layer of the first magnetic recording medium through an optical system including an optical filter and a cylindrical lens! This is because unevenness is formed in the magnetic layer according to the signal.

Magnetic recording! ! Another advantage is that even if the width of the reproducing air head in the dependent device differs, it can be easily accommodated by changing the focal length of the cylindrical lens, changing the transmittance of the optical filter, etc.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a cross-sectional view for explaining the six-layer transfer process according to the present invention, and M21/ is a cross-sectional view for explaining the six-layer transfer process according to the present invention. Figure 4 (1) (b) shows the diameter of the laser beam before and after passing through the optical filter. Indicates the intensity distribution in the direction T factor. Figure 115 is a diagram showing an example of the transmission characteristics of the same optical filter.
@Figure 6 is a diagram showing a specific configuration diagram of the same optical filter, 弗7
Figure 3) (b) shows the optical filter used in this invention as well as σ)
The transmission characteristics in the track width direction and wavelength direction are shown for example TI
/, No. 81J (4) (b) is a diagram showing the intensity distribution of the laser beam in the track width direction S and wavelength direction after passing through the optical filter, and FIG. 9 is a factor showing a specific example of the configuration of the optical filter. There it is. 1--First a-like recording medium, 4--@2 magnetic recording medium, 7.8-Magnet, 11--Laser oscillator, 12--Intensity Im device, 1-J---Recording signal , 14-Optical filter, ts-V lintrical lens, Figure 2 □ Figure 13, 1s +6 1 1°1. Figure 1g4 Figure 5 (word';,, xm>

Claims (1)

[Claims] When the second magnetic recording medium l comes into contact with the first magnetic recording medium in which signals are recorded in the form of unevenness on the magnetic layer, these! J1. 1st. Magnetic recording medium i: magnetic field? From addition 62, 1st
The signal V recorded in the form of unevenness on the magnetic recording medium of
A laser beam modulated by a recording signal is applied to the magnetic layer of the magnetic recording medium or the non-magnetic layer on which this magnetic layer is formed! Irradiation is performed through an optical system Y that includes a cylindrical lens and an optical filter that flattens the intensity distribution of the laser beam on the d-column layer or non-magnetic layer at least in the track width direction at least within the track width. Magnetism is characterized by forming unevenness according to the above signal. Muyo recording device.