JPH11144293A - Optical head and optical recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical head which is capable of enhancing a tracking accuracy and reading and writing accuracies and which is small in size and light in weight and an optical recorder in which the optical head is used. SOLUTION: This head is an optical head in which a solide-state immersion lens 12, an objective lens 13 and an optical mirror 14 are integrally formed on a slider 11 to be floated by air flow to be formed while rotating an optical recording medium 1 in an optical head which converges a luminous flux on the revolving optical recording medium. Moreover, this optical recorder is a recorder which supports an optical head 10 with the revolving optical recording medium 1 and a gap and which performs the writing or reading of information on the recording medium 1 via the optical head 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical head and an optical recording apparatus for recording or reproducing information by irradiating a light beam onto an optical recording medium.

[0002]

2. Description of the Related Art In recent years, in an optical recording apparatus for optically recording or reproducing information, in particular, a magneto-optical recording apparatus, a solid immersion lens (hereinafter, referred to as "SIL") for the purpose of improving recording density. ), A recording method in which the effective numerical aperture of the optical system is 1 or more has been proposed. An experimental example in which such a SIL is mounted on a flying head of a magneto-optical disk has been reported by BDTerris et al.
ysics Letter, 68 (2), 141-143 (1996).
FIG. 6 shows the flying head. In FIG. 6, a head 20 includes a slider 21 supported by a suspension 24 and an SIL mounted on the slider 21.
22 and the SIL 22 disposed above the SIL 22
The objective lens 23 is formed separately from the slider 21. The slider 21 is floated by an air bearing utilizing an air flow generated by rotation of the magneto-optical disk 30, and the SIL 22 mounted on the slider 21 is configured to maintain a constant gap with the magneto-optical disk surface 30a.

[0003]

However, as in the prior art, the head 20 has only the SIL 22 mounted on the slider 21 and another optical member such as the objective lens 23 is formed separately from the slider 21. If you do
For example, when the relative position between the central axis of the SIL 22 and the central axis of the objective lens 23 is parallel to the plane (x
There is a disadvantage that the displacement occurs in the (y-plane) and the tracking accuracy is reduced. The SIL 22 and the objective lens 23
The distance in the optical axis (z-axis) direction also fluctuates, so that the spot diameter of the light beam condensed on the magneto-optical disk surface 30a fluctuates. Furthermore, since the entire structure of the head 20 including the arm supporting the head 20 is large and thick, it is difficult to reduce the size of the optical recording apparatus. It has been difficult to configure a recording device in which a plurality of recording devices are stacked. Therefore, an object of the present invention is to provide a small and lightweight optical head which improves tracking accuracy, reading and writing accuracy, and an optical recording apparatus using the optical head.

[0004]

According to the present invention, there is provided an optical head for focusing a light beam on a rotating optical recording medium, the optical head being formed by rotating the optical recording medium. Slider (11) levitated by air flow
An optical head (10), wherein a solid immersion lens (12), an objective lens (13), and an optical mirror (14) are integrally formed. The present invention also provides an optical recording device that supports an optical head with a gap from a rotating optical recording medium and writes or reads information on or from the optical recording medium via the optical head. A solid immersion lens (12), an objective lens (13), and an optical mirror (14) are integrally formed on a slider (11) floating by an air flow formed by rotating 1), and an arm ( 15), wherein the arm (15) is configured such that the optical head (10) is movable in the radial direction of the optical recording medium (1).

[0005]

1 and 2 show an optical recording apparatus according to a first embodiment of the present invention. FIG. 1 is a plan view, and FIG. 2 is a sectional view. FIG. 2 shows a cross section taken along the AA plane in FIG. In the optical recording apparatus of the present embodiment, an optical disk 1 as an information recording medium is configured to be rotatable around a rotation shaft 2a by a spindle motor 2, and the optical disk 1
An optical head 10 supported on the tip end of a head arm 15 is disposed above the optical disk 1 while maintaining a constant distance from the optical disk 1. Note that the rotation direction of the optical disk 1 is a direction away from the head arm 15 to the optical head 10 (the direction of the arrow in the figure). The head arm 15 includes an arm body 15a made of a rigid body and a suspension 15b formed at an end portion and made of an elastic body. The optical head 10 is attached to a suspension 15b at the end portion.
The end of the arm body 15a on the side opposite to the optical head 10 side is attached to the rotating shaft 3a of the voice coil motor 3, and the optical head 10 is swung about the rotating shaft 3a as a center of rotation to move the optical head 10 in the radial direction of the optical disc 1. It is configured to be able to move at high speed.

The optical head 10 has a slider 11,
The slider 11 is formed so as to float by an air bearing utilizing an air flow generated by the rotation of the optical disc 1. The slider 11 has an SIL 12 and
The objective lens 13 and the microprism 14 are formed integrally along the optical path of the laser light L. The portion of the slider 11 sandwiched between the objective lens 13 and the SIL 12 is cut out to form a gap 17. In the microprism 14, a high reflection film 16 for reflecting the laser beam L is provided on a prism surface 14a of the microprism 14 to form a mirror surface.

The operation of the optical recording apparatus according to the embodiment will be described. By rotating the optical disc 1 at a predetermined speed to generate an air flow on the optical disc recording surface 1a, the slider 11 floats with a small gap from the optical disc recording surface 1a by an air bearing. The laser light L is emitted from a fixed optical system (not shown) arranged near the rotation axis 3a of the voice coil motor 3 and is converted into a parallel light beam by the optical head 1.
It is led to 0. In the optical head 10, the laser light L is reflected by the reflection surface 14 a of the microprism 14 and enters the objective lens 13. The laser beam L that has passed through the objective lens 13 passes through the gap 17 and enters the SIL 12, where it converges and focuses a recording spot on the optical disc recording surface 1a. Thus, information is recorded on the optical disk recording surface 1a, or information on the optical disk recording surface 1a is reproduced.

When the optical disk 1 is rotated at a constant speed, the gap between the optical disk 1 and the slider 11 is kept constant. Accordingly, the gap between the optical disk 1 and the slider 11 floating on the optical disk 1, that is, the floating amount of the slider 11 is made to correspond to the distance between the SIL 12 and the focal point of the recording spot, so that the recording spot is formed. Since the light can be focused on the optical disk recording surface 1a, the constant rotation speed of the optical disk 1 and the slider 11
Focusing of the laser beam L can be automatically performed by designing the flying height of the laser beam L to be optimal. The scanning of the optical head 10 in the radial direction of the optical disc 1, that is, tracking, is performed by controlling the rotation of the voice coil motor 3. The rotation of the voice coil motor 3 is controlled by the control device 4.

As described above, by forming the optical components necessary for the optical head 10, that is, the SIL 12, the objective lens 13, and the microprism 14 integrally with the slider 11, the relative positional relationship between the respective optical components can be improved. Fixed. This stabilizes the optical path of the laser beam L and eliminates fluctuations in the spot diameter, so that tracking can be performed stably and reading and writing accuracy is improved.
Further, the entire optical head 10 can be reduced in size, thickness, and weight. The optical disk 1 and the optical head 10
And a multi-platter optical recording apparatus in which a plurality of optical recording apparatuses are stacked in the same housing, so that a small-sized and large-capacity optical recording apparatus can be realized.

If the slider 11 is formed of a material transparent to the laser beam L, the slider 11 has an SI
It is not necessary to form a gap 17 between L12 and the objective lens 13. In the present embodiment, the head arm 15 is driven in the radial direction of the optical disk 1 by using the voice coil motor 3 which is a rotary actuator, but a linear actuator may be used.

FIG. 3 shows an optical recording apparatus according to a second embodiment of the present invention. In the optical recording apparatus of the present embodiment, a micro mirror 51 is arranged as an optical mirror instead of the micro prism 14 of the first embodiment. Micro mirror 51
Is formed by providing a high reflection film 52 on one side surface of a block of a suitable material (the same material as the slider 11). In addition, a square-shaped concave portion 41 surrounding the SIL 12 is provided on the bottom surface 11a of the slider 11, and in the concave portion 41, FIG.
The micro coil 42 having the coil-shaped wiring pattern shown in FIG. Using the micro coil 42,
By performing so-called magnetic field modulation, recording pits can be overwritten on the optical disc 1.

FIG. 5 shows an optical recording apparatus according to a third embodiment of the present invention. In the optical recording apparatus of the present embodiment, a fine movement actuator 54 is attached to the micro mirror 53. The fine movement actuator 54 is configured to swing the micromirror 53 surface around a line of intersection between the incident surface of the laser beam L and the micromirror 53 surface as a rotation center axis, and to change the installation angle of the micromirror 53. ing. By operating the fine movement actuator 54, the light beam to the optical disk 1 can be tilted by a small angle in the radial direction of the optical disk 1. Thus, the tracking operation of the optical head 10 is roughly adjusted by the voice coil motor 3 and the installation angle of the micro mirror 53 is adjusted and finely adjusted by the fine movement actuator 54 on the slider 11 to perform two-stage control. And extremely high-accuracy tracking becomes possible.

[0013]

As described above, according to the present invention, the optical components necessary for the optical head, that is, the SIL, the objective lens, and the microprism are integrally formed on the slider, so that the optical components between Since the relative positional relationship is fixed, tracking can be performed stably, and reading and writing accuracy is improved. Further, the entire optical head can be reduced in size, thickness, and weight. Further, a multi-platter type optical recording apparatus in which a plurality of optical recording media and optical heads are laminated in the same housing can be configured, and a small-sized large-capacity optical recording apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a plan view of an optical recording apparatus according to a first embodiment.

FIG. 2 is a sectional view of the optical recording apparatus according to the first embodiment.

FIG. 3 is a sectional view of an optical recording apparatus according to a second embodiment.

FIG. 4 is a bottom view of one embodiment of the microcoil.

FIG. 5 is a sectional view of an optical recording apparatus according to a third embodiment.

FIG. 6 is a cross-sectional view of an optical recording device according to a conventional optical head device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk 1a ... Optical disk recording surface 2 ... Spindle motor 2a ... Spindle motor rotating shaft 3 ... Voice coil motor 3a ... Voice coil motor rotating shaft 10 ... Optical head 11 ... Slider 12 ... Solid immersion lens (SIL) 13 ... Objective lens 14 ... microprism 14a ... microprism reflection surface 15 ... head arm 15a ... arm body suspension 15b ... suspension 16, 52 ... high reflection film 17 ... space 41 ... recess 42 ... microcoil 51,53 ... micromirror 54 ... fine actuator L ... Laser light

Claims (7)

[Claims] An optical head for condensing a light beam on a rotating optical recording medium, wherein a slider immersed in an air flow formed by rotating the optical recording medium is provided with a solid immersion lens, an objective lens, and an optical mirror. An optical head, wherein is integrally formed. 2. The slider according to claim 1, wherein the slider has an air gap or a transparent body that transmits the light flux along an optical path of the light flux, and the objective lens is opposite to the optical recording medium side of the gap or the transparent body. 2. The optical head according to claim 1, wherein the solid immersion lens is disposed on a side of the gap or the transparent body on the optical recording medium side. 3. 3. The optical head according to claim 1, wherein the optical mirror is formed by an optical prism and a reflection film provided on a prism surface of the optical prism. 4. The optical head according to claim 1, wherein the slider is provided with a coil for applying an external magnetic field to the optical recording medium. 5. The optical head according to claim 1, wherein an actuator for changing an installation angle of the optical mirror is arranged in the optical head. 6. An optical recording apparatus which supports an optical head with a gap from a rotating optical recording medium and writes or reads information on or from the optical recording medium via the optical head. The solid immersion lens, the objective lens, and the optical mirror are integrally formed on a slider that floats by an air flow formed by rotating the lens, and are supported by an arm. An optical recording device configured to be movable in a radial direction of a medium. 7. The optical recording apparatus according to claim 6, wherein a plurality of said optical recording media and said optical head are stacked in a direction of a rotation axis of said optical recording medium.