JPH0371401A - Modulation magnetic field generator - Google Patents

Abstract

PURPOSE:To obtain a modulation magnetic field generator in which damage due to contact at a generator side and the flaw of a magneto-optical recording medium are reduced and a gap between them is reduced as far as possible by composing the taking up part of a coil for magnetic field generation in such a way that the inner peripheral part of the part is neighbored to the recording medium nearer than the outer peripheral part. CONSTITUTION:A curved surface is formed so that a distance between the magneto- optical recording medium can be reduced as approaching the plane of a magnetic block 1 confronting with the medium from an outer periphery to an inner periphery, then a terminal 4 is formed on the plane. And a connecting point 6 and an insulating layer 7 leaving the outer end of the terminal 4 as it is are laminated on the inner end of the terminal so as to comprise the different connecting points 6 at an upper side. Also, a print coil 3 is formed on the insulating layer with a spiral conductor pattern, and the inner end of the coil is connected to the connecting point 6, and also, the outer end is connected to a terminal 5 provided at the magnetic block 1 from the edge of the insulating layer 7. In such a way, it is possible to reduce a probability to roll in dust, etc., and to evade or reduce the damage due to the contact is made at a wide area even when both media come into contact.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a modulated magnetic field generating device for magneto-optical recording.

(Prior Art) Conventionally, this type of modulated magnetic field generating device generally has a configuration as shown in FIG. 3. Here, the modulated magnetic field generating device 32 is disposed with an arm 35 at a position facing the optical head 31 so as to sandwich the magneto-optical disk 30, and receives a signal current from an information signal source 33 to the pulley. On the other hand, the magneto-optical disk 30 is rotationally driven by a swivel motor 34. The modulated magnetic field generating device 32a, for example, as shown in FIG. 4, forms a terminal 4 on a magnetic material plate with a conductor and a middle turn, and forms a connection point 6 extending upward at the inner end thereof. As shown, an insulating layer 7 is laminated, leaving the connection point and terminal 4, and a printed coil 3 is formed here with a spiral conductor i9 turns, thereby connecting the inner end of the coil to the connection point 6, and connecting the coil to the connection point 6. The outer end is configured to be connected to a terminal 5 provided from the insulating layer 70 grade to the magnetic material layer 1.

The modulated magnetic field generator 32 needs to apply a magnetic field necessary and sufficient to reverse the direction of magnetization of the magneto-optical recording medium, here the magneto-optical disk 30.

However, it is difficult to obtain a desired magnetic field strength due to demands for increased recording density and high-speed operation. Therefore, by increasing the signal current supplied to the modulated magnetic field generator, it is possible to obtain the desired magnetic field strength, but this increases power consumption and
This causes problems such as heat generation and disconnection of the conductor nosoturn.

(Problem to be Solved by the Invention) In order to obtain the desired magnetic field strength without increasing the signal current supplied to the modulated magnetic field generator, it is necessary to reduce the distance t between the modulated magnetic field generator ε and the magneto-optical recording medium. However, due to geometrical defects such as surface runout, uneven thickness, warping, etc. of the recording medium, the modulated magnetic field generating device may come into contact with the surface of the recording medium, or dust or the like may be caught in the recording medium. The surface is scratched or scratched to a depth greater than the thickness of the protective film. There is a risk that the casing and the modulated magnetic field generator itself may be damaged, making it impossible to perform recording or reproduction.

(Object of the Invention) The present invention has been made based on the above-mentioned circumstances, and even if there is a shape defect such as surface runout, uneven thickness, or warpage on the recording medium side, the modulated magnetic field generating device side due to contact Avoiding damage and scratches on the magneto-optical recording medium, which can be reduced.
It is an object of the present invention to provide a modulated magnetic field generating device that can reduce the distance between the two as much as possible.

(Means for Solving the Problems) Therefore, in the present invention, a magneto-optical recording medium is irradiated with a light beam from an optical head to raise its temperature, and a modulating magnetic field is applied to change the orientation of magnetic domains having magnetization orientation. , in a magneto-optical recording system for recording information, a plane in which a magnetic field generating coil, which is arranged so that the main magnetic field component is perpendicular to the recording layer of the recording medium, faces the recording layer of the recording medium. The recording medium is provided with a spiral winding portion, and the winding portion is configured such that its outer circumferential portion as well as its inner circumferential portion are close to the recording medium.

(Function) Therefore, even if there is a tilt of the modulated magnetic field generator, a surface runout of the magneto-optical recording medium, uneven thickness, warping, etc., the two
Even if there is contact, the contact is over a wide area, so damage can be avoided.
Some can be alleviated. Therefore, since the distance between the two can be made as small as possible, the desired magnetic field strength can be obtained with relatively low electric power.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to the drawings. Here, as shown in FIGS. 1(a) and 1(b), as the surface of the magnetic material facing the magneto-optical recording medium approaches from the outer circumference to the inner circumference, the distance from the recording medium becomes smaller. A terminal 4 is formed on this surface by conductor turns, and the above connection point 6'h= and the outer end of the terminal 4 are formed so as to form a connection point 6 extending upward at the inner end of the terminal 4. The insulating layer 7 is laminated thereon, leaving . A spiral conductor is placed on the insulating layer 7 of the housing. The printed coil 3 is formed by turning, and the inner end of the coil is connected to the connection point 6, and the outer end is connected to the terminal 5 provided from the green of the insulating layer 7 to the magnetic material layer 1. do. A comparison of the spacing between the magneto-optical recording media of the modulated magnetic field generating device having the above configuration and the conventional modulated magnetic field generating device shown in FIG. 4 will be explained with reference to FIG. 2. Now, assuming that the modulating magnetic field generating device is tilted approximately 10 degrees from a plane parallel to the magneto-optical recording medium, as is clear from Fig. 2, the opposing surface of the modulating magnetic field generating device becomes a curved surface. Therefore, the above-mentioned interval is reduced by a distance C compared to the conventional case (a). In other words, the distance may be narrowed by the distance C. In addition, in the conventional example shown in FIG. 2(a), the outermost circumferential machining and groove portions are in contact with the surface of the recording medium, so contact may occur due to surface runout, thickness unevenness, curling, etc. on the recording medium side. However, in the form of the present invention shown in FIG. 2(b), a part of the curved surface comes into contact with a large area, so the above-mentioned problem occurs. Injuries can be avoided and some b can be reduced.

In the above embodiment, reference numeral 2 denotes a protective layer covering the opposing surface of the modulated magnetic field generator.

In the embodiment described above, the curved surface of the opposing surface may be a cubic curved surface such as a spherical surface, but when manufacturing considerations are taken into consideration, it may be a quadratic curved surface that is cylindrical with respect to the rotation direction of the recording medium.

(Effects of the Invention) As described in detail above, the present invention prevents dust, etc., from mounting the modulated magnetic field generator even if there is a tendency due to error, surface runout, thickness unevenness, or warpage of the magneto-optical recording medium. The probability of getting caught is reduced, and even if contact occurs, the contact occurs over a wide area, so damage can be avoided or reduced. Therefore, the distance between the two can be reduced as much as possible, the desired magnetic field strength can be ensured even with a small output, and the reliability of both can be improved.

[Brief explanation of drawings]

FIGS. 1(a) and (b) are a top view and a sectional view showing an embodiment of the present invention, and FIGS. 2(a) and (b) are schematic diagrams showing a comparison between the conventional example and the embodiment of the present invention. FIG. 3 is a schematic diagram of a magneto-optical recording device showing the configuration of a bias magnetic field generator, and FIG. 4 is a top view and a sectional view of a conventional example. l... Magnetic block, 2... Protective film (insulating layer),
3... Printed coil, 4, 5... Terminal, 6...
Connection point, 7... Absolute R layer.

Claims (1)

[Claims] In the magneto-optical recording method, in which information is recorded by irradiating a magneto-optical recording medium with a light beam from an optical head to raise the temperature and applying a modulating magnetic field to change the orientation of magnetic domains with magnetization orientation, the main magnetic field is A magnetic field generating coil arranged such that a component thereof is perpendicular to the recording layer of the recording medium has a spiral winding portion in a plane facing the recording layer of the recording medium, and the winding A modulated magnetic field generating device characterized in that the inner circumferential portion of the portion is configured such that an inner circumferential portion thereof is closer to the recording medium than an outer circumferential portion thereof.