JPH04219652A - Floating head of magneto-optical recording type recorder - Google Patents

Abstract

PURPOSE:To simplify the production of the floating head by forming a magnetism generating means of a magnetic field generating coil which is wound over the entire periphery on the side face of a floating body and nearly in parallel with an optical recording medium. CONSTITUTION:The magnetic field generating coil 43 built in the floating head 4 is energized to generate the perpendicular magnetic field in the direction reverse from the magnetization direction of a magnetic film 10 of a magneto- optical disk 1 at the time of recording information with this recorder. On the other hand, the laser beam from the semiconductor laser modulated in correspondence to recording information is converged toward the magnetic film 10 surface of the magneto-optical disk 1 via a collimator lens, beam shaping prism, beam spliiter, relay lens, and reflection prism 26 to direct the magnetization direction of this part reverse from the ambient, by which the recording of the information is executed. The need for providing the groove for mounting the coil 43 on the floating body 41 is eliminated in such a manner and the number of turns of the magnetic field generating coil 43 wound on the side face of the floating body 41 can be made large than heretofore. The production of the floating head is thus simplified.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a floating head for a magneto-optical recording device, and in particular to an improvement in a floating head that is easy to manufacture and capable of forming a strong perpendicular magnetic field toward the surface of an optical recording medium. be.

0002

[Prior Art] As this type of magneto-optical recording device,
To explain the recording principle using the optical modulation type magneto-optical recording method as an example, first, as shown in FIG. While applying an external magnetic field in the direction of the arrow to the optical recording medium,
In this state, a light beam from a light source modulated in accordance with the recorded information is passed through the objective lens (b) to the magnetic film of the optical recording medium (
a) Raise the temperature of the irradiated area to the Curie point by focusing it on the surface. In this case, when the temperature of the irradiated part of the magnetic film (a) reaches the Curie point, the magnetization disappears.

[0003] When the irradiation position of the light beam moves to another part as the optical recording medium moves, the temperature of the above part decreases, and the external magnetic field reverses the magnetization direction of the surrounding area (upward in the figure). It is magnetized again, and information is recorded on the magnetic film (a) as a reversal of magnetization, forming recording pits (c).

On the other hand, during reproduction, when a light beam is irradiated onto the magnetic film (a) of the optical recording medium as shown in FIG.
Due to the magnetic Kerr effect, the light is reflected as light that is optically rotated according to the magnetization direction of the irradiated area, and recorded information is reproduced by detecting the magnetization direction from the polarization direction of this reflected light.

[0005] Furthermore, when erasing recorded information, FIG.
As shown in Figure 1, a light beam is irradiated onto the recorded area to temporarily raise the temperature of this area to the Curie point, and an external magnetic field is applied in the opposite direction to that used during recording on the optical recording medium (downward in the figure) to erase the information. This is what we do.

By the way, in a conventional magneto-optical recording device, the means for generating an external magnetic field is a permanent magnet provided at a portion facing an optical head (He) with an optical recording medium (d) in between, as shown in FIG. It was composed of a magnet or electromagnet (e).

Therefore, as the optical head (He) equipped with the objective lens (b) moves and scans, the permanent magnet or electromagnet (e) also needs to move and scan in the radial direction of the optical recording medium (d). Therefore, there is a drawback that the driving means is complicated.

[0008] Therefore, Japanese Patent Application Laid-Open No. 60-261052 discloses a ``floating type'' optical head incorporating magnetic field generating means as a means to eliminate the above-mentioned drawbacks.

That is, this floating head (H) is shown in FIG.
~As shown in Figure 15, there is an air slider (H1) made of a soft magnetic material that floats due to the air flow accompanying the rotation of the optical recording medium (d), and a light source (f) attached to the air slider (H1). A prism (H2) that makes the beam incident on the optical recording medium (d) side, and the air slider (H
1) is attached to the optical path opening (H3) and the prism (H
2) an objective lens (b) for converging the light beam incident on the magnetic film (a) surface of the optical recording medium (d); and an aperture on the optical recording medium (d) side of the air slider (H1). Attachment groove (H4) provided along the opening edge of the section (H3)
The main part thereof consists of a coil (g) which is wound around the magnetic film (a) of the optical recording medium (d) and forms a substantially perpendicular magnetic field to the magnetic film (a) of the optical recording medium (d). ) is moved and scanned in the radial direction of the spring-like suspension (
k) and is disposed near the optical recording medium (d).

[0010] In this floating head (H), the coil (g) as a magnetic field generating means is mounted on the head side, so it has the advantage that its driving means is simplified compared to conventional devices. and prism (H2),
Since only the minimum number of components such as the objective lens (b) and the coil (g) are mounted on the air slider (H1), the head is lighter and access time is shortened, and the optical recording medium (d) Due to the configuration in which the air slider (H1) is floated by the air flow accompanying the rotation of the lens, it is possible to maintain a constant distance between the optical recording medium (d) and the air slider (H1), and the focusing mechanism of the objective lens (b) is It also has the advantage of simplifying the process.

[0011]

[Problems to be Solved by the Invention] By the way, although the floating head (H) equipped with the coil (g) as a magnetic field generating means has the above-mentioned advantages, the air slider (H1) itself is In order to make it float due to the flow, it is necessary to make it extremely small and lightweight, and it is difficult to machine the mounting groove (H4) for the coil (g) on this small air slider (H1). There was a problem with mass production.

Moreover, since the number of turns of the coil (g) wound in the mounting groove (H4) is also limited due to space reasons, the magnetic field strength generated from this coil (g) is also weak, and therefore recording Another problem is that it is difficult to generate the magnetic field strength required for erasing.

Therefore, in a magneto-optical recording device equipped with this type of floating head, a light beam is irradiated from the magnetic film (a) side of the optical recording medium (d) as shown in FIG. A method is adopted in which the distance between the coil (g) of the floating head and the magnetic film (a) is narrowed, thereby determining the required magnetic field strength.

However, when such a method of irradiating the light beam from the magnetic film (a) side is adopted, compared to the conventional method of irradiating the light beam from the transparent substrate (d') side, as shown in FIG. There is a problem that the recording/reproducing performance deteriorates significantly due to the fact that the light beam is easily affected by scratches, dust, etc. that exist on the irradiation side of the light beam. There was a problem in that compatibility with other types of recording media for recording and playback was lost.

The present invention has been made in view of the above-mentioned problems, and its object is to provide a magneto-optical recording device which is easy to manufacture and which can form a strong perpendicular magnetic field toward the surface of an optical recording medium. The purpose is to provide a floating head.

[0016]

[Means for Solving the Problems] In other words, the present invention provides a floating body that is placed near a rotating optical recording medium and floats due to the airflow accompanying the rotation of the optical recording medium, and a floating body that is provided on the floating body and that emits light from a light source. An objective lens for converging a beam onto a convergence surface of an optical recording medium, and a magnetic field generation means provided on the floating body for forming a magnetic field toward the convergence surface of the optical recording medium, the magnetic field generation means forming a magnetic field. The floating head of a magneto-optical recording device records or erases information by converging the beam on the convergence surface of an optical recording medium in a state in which the magnetic field generating means generates light over the entire periphery of the side surface of the floating body. This device is characterized by being composed of a magnetic field generating coil wound approximately parallel to the recording medium.

In such a technical means, the material constituting the floating body may include non-magnetic materials such as glassy carbon, barium titanate, calcium titanate, etc.
Soft magnetic materials such as n-Zn ferrite, Ni-Zn ferrite, and permalloy can be used. In particular, when the floating body is made of the latter soft magnetic material, the floating body is magnetized by the magnetic field generating coil wound around the entire side surface of the floating body, so it is more effective than when non-magnetic material is used. This has the advantage that a large generated magnetic field can be obtained.

Next, on the bottom side of the floating body, in order to efficiently receive floating pressure from the optical recording medium,
It is necessary to form at least a sliding surface and an air introduction surface. In addition, for the purpose of stabilizing the floating movement of the floating body, there are grooves that allow air to escape along the length of the floating body, i.e.
A central relief portion may also be formed. In this case, the number and shape of the grooves can be arbitrarily set depending on the purpose.

Furthermore, the shape of the optical path opening formed in the floating body and to which the objective lens is attached is formed into a substantially circular shape in accordance with the beam spot shape. When constructed from a soft magnetic material, by providing a gradient inward in the direction of beam incidence on the inner wall surface of the optical path opening, it is possible to concentrate the magnetic field from the magnetic field generating coil at the beam convergence point of the optical recording medium. It has the following advantages. In particular, the effect becomes remarkable when the slope angle of the inner wall surface of the optical path opening is set to be substantially the same as the beam condensing angle.

On the other hand, the magnetic field generating coil described above can be installed at any location as long as it is wound around the entire side surface of the floating body, but it is stronger on the optical recording medium side if it is placed closer to the optical recording medium side. This is advantageous in that a magnetic field can be obtained. Further, the number of turns of the magnetic field generating coil is set to an appropriate value depending on the relationship between the required magnetic field strength and the weight of the floating body, which increases according to the number of turns.

[0021] The scope of application of this technical means is not limited to magneto-optical recording devices using the "light modulation type magneto-optical recording system";
Naturally, it can be applied to a magneto-optical recording device using the "magnetic field modulation type magneto-optical recording method," and the optical recording medium incorporated in this device can be any medium such as a magneto-optical disk or a magneto-optical card. can be applied.

[0022]

[Operation] According to the above-mentioned technical means, since the magnetic field generating means is constituted by a magnetic field generating coil wound approximately parallel to the optical recording medium over the entire circumference of the side surface of the floating body,
There is no need to provide a coil mounting groove in the floating body, and the number of turns of the magnetic field generating coil wound around the side surface of the floating body can be increased compared to the conventional case.

[0023]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

That is, the magneto-optical recording device according to the embodiment has a magneto-optical disk (1) as shown in FIGS. 1 to 5.
a movable body (2) placed near the magneto-optical disk (1) to move and scan the recording area; a floating head (4) mounted on the movable body (2) via a spring material (3); , the main part thereof is composed of a driving part (5) that moves and scans the movable body (2), and as shown in FIG. 6, a semiconductor laser (80) which is a light source and a light source Collimator lens (
81), a beam shaping prism (82) that shapes the shape of the beam, and a beam splitter (83) that separates the incident beam entering the magneto-optical disk (1) and the reflected beam from the magneto-optical disk (1). 95), this beam splitter (83), and a pair of focus adjustment relay lenses (84) provided between (95) and the floating head (4).
and a λ/2 wavelength plate (86), a polarizing beam splitter (87), and a focusing lens (88) provided between the reproduced signal light receiving element (85) and the beam splitter (95),
A half mirror (90
), a focusing lens (91) and a knife edge (92);
A focusing lens (94) provided between the half mirror (90) and the light receiving element (93) for tracking error detection
It is made up of the following. In this magneto-optical recording device, the knife-edge method is used for focusing control as described above, and the push-pull method is used for tracking control.

First, the movable body (2) is composed of a bobbinless drive coil (20) formed by bonding wound coils with epoxy adhesive and integrally molding them, as shown in FIGS. 2 and 5. A coil body (22) formed into an elliptical cylindrical shape and having a rectangular opening (21) on the side facing the magneto-optical disk (1), and an opening (21) formed in the coil body (22). The coil body (22
) and a pair of reinforcing coil walls (25) forming an insertion portion (24) between the inner wall (23) of the coil body (22) and facing the opening (21) in the coil body (22). On the inner wall surface, there is a reflecting prism (26) that guides a laser beam from a light source (not shown) toward the magneto-optical disk (1).
is located.

Further, as shown in FIGS. 1 to 3, the floating head (4) floats due to the air flow accompanying the rotation of the magneto-optical disk (1) and directs the laser beam from the light source onto the magneto-optical disk (1). A floating body (41) made of alumina ceramics with an opening (40) for the optical path introduced to the side.
is attached to the optical path opening (40) of this floating body (41) to direct the laser beam from the light source to the magneto-optical disk (1).
A plastic objective lens (
42) and a magnetic field generating coil (43) wound around the entire side surface of the floating body (41),
The air inflow end and air outflow end of the surface of the floating body (41) facing the magneto-optical disk (1) are provided with tapers (44) and (45) for smoothing the inflow and outflow of air, and Approximately at the center of the slider surface (46) there is a center relief part (4) that stabilizes the floating movement of the floating head (4).
7), and is attached to the opening (21) of the movable body (2) via a phosphor bronze spring material (3) that biases it toward the magneto-optical disk (1). It is something.

[0027] Furthermore, the drive unit (5) is configured to move the movable body (2)
An aluminum carriage (50) provided on the bottom side of the body and fitted into a linear bearing (6), and the movable body (2)
) A pair of pure iron magnetic yokes (51) (51) are inserted into the insertion portions (24) of the magneto-optical disk (1) and are arranged across the track direction of the magneto-optical disk (1).
1) Arc-shaped magnets (52) (52) arranged along the length and made of rare earth iron permanent magnets, and a pure iron magnetic retainer that holds these magnets (52) (52). body(
53) and a pure iron magnetic fixed stand (54) that supports the entire members such as the carriage (50) and the linear bearing (6).

In the magneto-optical recording device configured in this way, the driving coil (20) is used as in the conventional device.
The movable body (2) moves in the track direction of the magneto-optical disk (1) due to the electromagnetic force accompanying the energization, and the floating head (4) is also moved and scanned along with this to perform track control, while the focus Floating head (4) for control
This is done by utilizing the floating phenomenon and the focus adjustment relay lens (84).

In order to record information using this magneto-optical recording device, a floating head (4
) to generate a perpendicular magnetic field in the opposite direction to the magnetization direction of the magnetic film (10) in the magneto-optical disk (1), while also generating a perpendicular magnetic field that is modulated in accordance with the recorded information. A laser beam from a semiconductor laser (80) is passed through a collimator lens (81) and a beam shaping prism (8
2), beam splitter (83), relay lens (84)
), and an objective lens (42) via a reflecting prism (26).
), the magnetic film (10) of the magneto-optical disk (1) is focused on the surface of the magnetic film (10), and the direction of magnetization of that portion is opposite to that of the surrounding area, thereby recording information.

Note that the reflected beam from the magneto-optical disk (1) returns along a part of the optical path and passes through the beam splitter (
83) and enters the light receiving element (85) for detecting the reproduced signal via the λ/2 wavelength plate (86), the polarizing beam splitter (87), and the focusing lens (88),
The light enters the light receiving element (89) for detecting a focusing error signal through the half mirror (90), the focusing lens (91), and the knife edge (92), and the light enters the light receiving element (93) for detecting the half mirror. The light enters through a mirror (90) and a focusing lens (94).

In order to reproduce the recorded information, the power to the magnetic field generating coil (43) must be stopped and the magnetic film (10) surface must be kept at a temperature that does not reach the Curie point so as not to adversely affect the recorded information. A modulated laser beam is applied to the above magnetic film (10).
Irradiates the surface. This laser beam is reflected as light that is optically rotated according to the magnetization direction of the irradiated area due to the magnetic Kerr effect, and the change in the polarization direction of this reflected beam is reflected by a beam splitter (83), a λ/2 wavelength plate (86), a Wollaston prism ( 87), half mirror (90) and focusing lens (
94), the light receiving element (93) discriminates the information, and the information is reproduced.

Next, to erase the recorded information, as shown in FIG. 8, the magnetic field generating coil (43) is energized in the opposite direction to generate a perpendicular magnetic field in the opposite direction to that during recording, while being unmodulated. A laser beam whose temperature reaches the Curie point of the magnetic film (10) at the irradiated area is focused onto the surface of the magnetic film (10) of the magneto-optical disk (1), and the magnetization direction of that area is aligned in the same direction as the surrounding area, thereby transmitting information. This is for erasing.

In this magneto-optical recording device, the magnetic field generating means incorporated in the floating head (4) is generated by a magnetic field generating coil (43) wound around the entire side surface of the floating body (41). This eliminates the need to provide a coil mounting groove in the floating body (41) as in the past, and the number of turns of the magnetic field generating coil (43) wound around the side of the floating body (41) is also lower than in the past. It becomes possible to increase the

Therefore, it has the advantage that manufacturing of the floating head (4) is simplified and productivity is improved, and a stronger perpendicular magnetic field can be generated toward the surface of the magneto-optical disk (1) than in the past. The transparent substrate (1) of the magneto-optical disk (1)
1) It becomes possible to irradiate the laser beam from the side.

Therefore, it has the advantage of being less susceptible to the effects of scratches, dust, etc. that exist on the laser beam irradiation side, and improves the recording and reproducing performance. This has the advantage of maintaining compatibility with other recording media that are irradiated with laser beams.

[0036]

According to the present invention, there is no need to provide a coil mounting groove in the floating body, and the number of turns of the magnetic field generating coil wound around the side surface of the floating body can be increased compared to the conventional one. Therefore, it has the effect of simplifying the manufacturing of the floating head and improving its productivity.In addition, it is possible to form a stronger perpendicular magnetic field toward the surface of the optical recording medium than in the past, so that the floating head faces the transparent substrate side of the optical recording medium. It becomes possible to irradiate the beam from For this reason, it is less susceptible to the effects of scratches, dust, etc. that exist on the beam irradiation side, and has the effect of improving recording and playback performance, and the beam is irradiated from the side of transparent substrates such as phase change optical recording media. This has the effect of maintaining compatibility with other recording media.

[Brief explanation of the drawing]

FIG. 1 is an enlarged perspective view of the main parts of a magneto-optical recording device according to an embodiment.

FIG. 2 is a sectional view taken along line II-II in FIG. 1;

FIG. 3 is a sectional view taken along line III-III in FIG. 1;

FIG. 4 is a partially enlarged view of FIG. 3;

FIG. 5 is a perspective view of FIG. 1 with the floating head and spring members omitted.

FIG. 6 is an explanatory diagram of a configuration of a magneto-optical recording device according to an embodiment.

FIG. 7 is an explanatory diagram when information is recorded in this magneto-optical recording device.

FIG. 8 is an explanatory diagram when erasing information in this magneto-optical recording device.

FIG. 9 is an explanatory diagram of the recording principle in a magneto-optical recording device.

FIG. 10 is an explanatory diagram of the reproduction principle in a magneto-optical recording device.

FIG. 11 is an explanatory diagram of the erasing principle in a magneto-optical recording device.

FIG. 12 is a sectional view of a main part of a conventional magneto-optical recording device.

FIG. 13 is a perspective view of a main part of a conventional magneto-optical recording device.

FIG. 14 is a perspective view of the floating head of FIG. 13;

15 is a sectional view taken along the line XIV-XIV in FIG. 14. FIG.

[Explanation of symbols]

1 Magneto-optical disk 4 Floating head 41 Floating body 42 Objective lens 43 Magnetic field generating coil

Claims (1)

[Claims] Claim 1: A floating body disposed near a rotating optical recording medium and floating by an air flow accompanying the rotation of the optical recording medium; The floating body includes an objective lens for converging, and a magnetic field generating means for forming a magnetic field toward the converging surface of the optical recording medium, which is provided on the floating body. In a floating head of a magneto-optical recording device that records or erases information by converging the beam, the magnetic field generating means generates a magnetic field that is wound around the entire side surface of the floating body substantially parallel to the optical recording medium. A floating head of a magneto-optical recording device characterized by being composed of a generating coil.