JPH02134752A - magneto-optical recording device - 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 magneto-optical recording device, and more specifically to a bias magnetic field generator that generates a bias magnetic field to be applied to an information recording layer during information recording. It is about improvement.

[Conventional technology]

Conventionally, a bias magnetic field generator in a magneto-optical disk recording device is constructed as shown in FIG.

The optical head 41 is movable in order to record information over the entire range of the information recording area 44 of the magneto-optical disk 40. Further, the bias magnetic field generator 42 generates a generally uniform /? It is fixedly provided on the opposite side of the optical head 41 with the magneto-optical disk 40 interposed therebetween so as to generate an ias magnetic field.

In another conventional example shown in FIG. 5, a bias magnetic field generator 52 is connected to an optical head 51 on the opposite side to the magneto-optical disk 50 by a support member 56. As shown in the figure, the center line of the light beam 57 for reading and recording information of the optical head 51 and the center line of the bias magnetic field generated by the bias magnetic field generator 52 are arranged so as to roughly coincide with each other. The Ias magnetic field generator 52 can move to follow the movement of the optical head 51 within the information recording area 54. In addition, as a modification of this conventional example, a part A of the support member 56 that connects the magnetic field generator 52 and the optical head 51 is made of a spring material having spring characteristics, and the magneto-optical disk 50 is There is also a conventional example of a magnetic field generator having a configuration in which the magnetic field generator 52 is slightly lifted in the perpendicular direction from the surface of the magneto-optical disk 50 by utilizing the airflow generated by the rotation.

[Problem to be solved by the invention]

However, the above conventional example has the following drawbacks. That is, in the first conventional example shown in FIG. 4, the bias magnetic field generator becomes large and heavy in order to generate a uniform noquious magnetic field over the entire area of the information recording area 44. Furthermore, the bias magnetic field generating power supply also becomes large.

Therefore, it is difficult to generate a uniform bias magnetic field over the entire information recording area 44, resulting in non-uniformity.

Non-uniformity of the magnetic field in the middle of the magneto-optical disk 40 depending on the location within the information recording area 44 causes non-uniformity in the size and shape of recording bits during recording, which causes errors. Furthermore, the power consumption for generating the 1 bias magnetic field is large, and the temperature of the magneto-optical disk 40 itself increases due to the temperature rise of the bias magnetic field generator 42, which further changes the recording conditions during recording, causing errors to occur. It also has a serious drawback:

In addition, in the conventional example shown in FIG. 5, the disadvantages of the large size, weight, and large power consumption of the Gius magnetic field generator in the conventional example shown in FIG. Since the center line of the bias magnetic field generated by the generator 52 must be aligned with the center line, it is difficult to improve design accuracy, and position adjustment is required during manufacturing.
It has the disadvantage of high cost. Furthermore, the movement of the optical head 51 during information retrieval causes vibration resonance of the support member 56, causing the bias magnetic field generator to move slightly. For this reason,·
The bias magnetic field generator 52 contacts the magneto-optical disk 50 and the magneto-optical disk 50 or the bias magnetic field generator 52
There is a risk of damage.

In addition, since the distance between the bias magnetic field generator 52 and the magneto-optical F4 disk 50 changes due to vibration, recording bits become non-uniform, similar to the conventional example shown in FIG. 4, and this has the disadvantage of causing errors. .

〔the purpose〕

The present invention has been made in view of the problems of the prior art described above, and its objectives are to achieve a reduction in size and weight of the bias magnetic field generator, and to adjust the position of the bias magnetic field generator and the light beam of the optical head. It is an object of the present invention to provide a magneto-optical recording device that eliminates the need for optical recording.

[Means to solve the problem]

According to the present invention, the above object is provided in a magneto-optical recording device that records information using a light beam and a magnetic field in a recording layer in which information is expressed by the direction of a magnetic domain having a boride orientation. A bias magnetic field generator that generates a magnetic field is disposed on the same surface side with respect to the recording layer, and a light beam emitted from the optical head is provided so as to pass through a part of the bias magnetic field generator. This is achieved by a magneto-optical recording device characterized in that the recording layer is irradiated through a through-hole.

〔Example〕

Hereinafter, embodiments according to the present invention will be specifically and detailedly explained based on the drawings.

FIG. 1 is a schematic side sectional view showing a first embodiment of the magneto-optical recording device of the present invention.

In the figure, 1 indicates a magneto-optical disk. la.

1b and 1cVi constitute the magneto-optical disk 1: a substrate, a recording layer, and a capture layer. 2 indicates an optical head, 3 indicates a bias magnetic field generator, and 41#i indicates a bias magnetic field generation power source. A support member 5 connects the optical head 2 and the bias magnetic field generator 3. Reference numeral 6 indicates a bias magnetic field generating coil, 7 indicates a light flux, 8 indicates an objective lens, and 9 indicates an objective lens drive coil.

The bias magnetic field generator 3 is made of a soft magnetic material (for example, a ferrite core), and a bias magnetic field generating coil 6 is wound around the magnetic material. - The bias magnetic field generating power supply 4 is electrically connected to the bias magnetic field generating coil 6, and supplies positive and reverse bias magnetic field generating currents to the bias magnetic field generating coil 6 according to the modulation signal.

The bias magnetic field generator applies a positive and a reverse bias magnetic field to the magneto-optical disk l using this bias magnetic field generating current.

Further, the .9ias magnetic field generator 3 is supported by the optical head 2 by a support member 5 having elastic properties. Since it is supported by the elastic support member 5, the magneto-optical disk 1
The distance between the surface of the magneto-optical disk 1 and the bias magnetic field generator 3 is kept almost constant by the air flow generated by the rotation of the magneto-optical disk 1.

Furthermore, the bias magnetic field generator 3 is provided in a direction perpendicular to the magneto-optical disk 1 with the center axis C of generating the bias magnetic field as its central axis, and the beam 7 emitted by the optical head 2 passes therethrough and has a large beam. A through hole having a diameter is provided.

As shown in FIG. 1, a light beam 7 of an optical head 2 for recording information on a magneto-optical disk is condensed by an objective lens 8 and focused on a recording layer Ib of a magneto-optical disk l. The objective lens 8 is controlled to move in the vertical direction by an objective lens drive coil 9 so as to accurately focus on the recording layer lb with respect to the surface deflection caused by the rotation of the magneto-optical disk l.

Further, a through hole is provided through the bias magnetic field generator 3 so that the light flux 7 substantially coincides with the bias magnetic field generation center axis C of the bias magnetic field generator 3.

The bias magnetic field generated by the bias magnetic field generator configured in this way is as shown in FIG.

That is, it becomes possible to apply a bias magnetic field almost perpendicular to the magneto-optical disk 1 to the center 11tIlC of the bias generating coil as shown in FIG. 2, and by reversing the polarity of the bias magnetic field generating power source, It becomes possible to apply opposite bias magnetic fields to the disk 1. When overriding the recording of information, the bias magnetic field is applied and reversed at high speed according to the state of the recorded information.

Furthermore, FIG. 3 shows the distribution of the bias magnetic field generated by the 9-ear magnetic field generator 3 according to the present invention, and shows the center axis of the bias magnetic field generation. A magnetic field distribution diagram with respect to distance d in the disk surface direction from . Although the bias magnetic field is somewhat small near the center axis of bias magnetic field generation, it is sufficiently uniform for the recording bits, so it is large enough to cause no problem, and a nearly uniform bias magnetic field is generated.

If the bias magnetic field generator 3 according to the present invention is used, the surface of the substrate 18 of the magneto-optical disk l and the bias magnetic field generated? 53
It is possible to easily set the distance between the two micrometers to several micrometers, and it is possible to effectively generate the bias magnetic field necessary for recording information in the recording layer. Compared to the Ias magnetic field generator 42, it is possible to reduce the magnetic field by a large amount, and high-speed magnetic field reversal operation is possible.

Furthermore, since information is recorded and reproduced from the optical head 2 with respect to the center axis of the bias magnetic field generated by the bias magnetic field generator 3, the magneto-optical disk 1 Mechanical precision for aligning the respective central axes on both sides and alignment after assembly are no longer required, making it possible to significantly reduce costs.

FIG. 6 shows another embodiment of the bias magnetic field generator according to the present invention. The bias magnetic field generator 63 is integrated with an objective lens 68 and an objective lens drive coil 69, and is an objective lens that moves to correct the focal shift caused by surface blur caused by the rotation of the optical disk 61. The bias magnetic field generator 63 also moves together with the lens 68 and the objective lens drive coil 69. Naive, the bias magnetic field generator 63 has a through hole through which the light beam 67 for recording and reproducing information on the magneto-optical disk 61 passes, and the optical axis C and the bias magnetic field generator 63
The center axes of the bias magnetic fields generated by the two are constructed so that they generally coincide.

In this embodiment, since the distance between the bias magnetic field generator 63 and the magneto-optical disk 61 is always controlled to be constant, it is possible to use a magneto-optical disk such as a floating type bias magnetic field generator that uses an air flow. The flying height does not change due to a change in relative speed with the bias magnetic field generator. Therefore, it is possible to always apply a constant bias magnetic field to the recording layer of the magneto-optical disk, and it is possible to suppress fluctuations in recorded bits, making it possible to realize a highly reliable memory system with few errors. .

[The young fruits of invention]

As described above in detail, by using the bias magnetic field generator according to the present invention, the height of the device can be reduced because the bias magnetic field generator and the optical head can be placed on one side of the magneto-optical disk. becomes. In addition, since the central axis of the generated bias magnetic field and the optical axis roughly match, the degree of freedom in design increases, and the center of the generated bias magnetic field of the bias magnetic field generator and the optical axis can be aligned during manufacturing. Since precision and θ4 adjustment are not required, it is also possible to significantly reduce costs.

Furthermore, the bias magnetic field generator can be placed very close to the magneto-optical disk recording J#IIK, and the magnetic field can be kept constant at all times, so power consumption can be reduced. Further, it is possible to form uniform recording bits and provide a high-speed and highly reliable apparatus.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing a first embodiment of a magneto-optical recording device of the present invention, FIG. 2 is a schematic side view of a bias magnetic field generator according to the present invention, and FIG. 3 is a schematic side view of a bias magnetic field generator according to the present invention. FIGS. 4 and 5 are side views showing a conventional example of a bias magnetic field generator, and FIG. 6 is a schematic side view showing another embodiment of the present invention. 2... Optical head, 3: Bias magnetic field generator, 4: /J
bias magnetic field generation power supply, 5: bias magnetic field generation coil, 6
: Luminous flux. Agent Patent Attorney Jo Taira Yamashita Figure 1 Figure 2 Figure Δ1-Medicine Figure 4 Square Figure

Claims (2)

[Claims] (1) In a magneto-optical recording device that uses a light beam and a magnetic field to record information on a recording layer that expresses information by the direction of magnetic domains having magnetization orientation, an optical head that emits the light beam and a bias magnetic field generator that generates the magnetic field. A light beam emitted from the optical head passes through a through hole provided through a part of the bias magnetic field generator, and the light beam emitted from the optical head passes through a through hole provided through a part of the bias magnetic field generator, A magneto-optical recording device characterized in that a recording layer is irradiated with light. (2) The normal line at the point where the light beam of the optical head for recording the information is focused on the information recording layer and the center line of the bias magnetic field generated by the bias magnetic field generator,
A magneto-optical recording device according to claim (1), characterized in that they substantially match.