JP2001034982A - Information recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a device and to speed up access time by providing a fixed optical system that is composed by fine optical parts at an arm part. SOLUTION: A fixed optical system that is provided at a swing arm is composed of three transparent substrates 51, 52, and 53, which are bonded one another. An optical system that is composed of a semiconductor laser 54 and mirrors 55 and 56 is provided on the substrate 51, an optical system that is composed of a collimate lens 57, a condensation lens 58, a mirror 59, a polarization beam splitter 60, and a λ/4 plate 61 is provided on the substrate 52, and an optical system that is composed of mirrors 62 and 63 and a photodiode 64 is provided on the substrate 53. Since an optical element for transmitting light is provided on the substrate 52 and only the optical system for reflection and a photosemiconductor element are provided on the substrates 51 and 53, so that a photodiode substrate, namely an Si substrate, can be used for the substrate 53, and a laser substrate, namely a compound semiconductor substrate, can be used for a laser substrate as a fixed optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a write-once optical disk device, an erasable phase-change optical disk or a magneto-optical disk device, a read-only optical disk device, and the like. The present invention relates to an information recording / reproducing apparatus for performing reproduction.

[0002]

2. Description of the Related Art FIG. 1 shows a configuration example of a conventional optical pickup. Referring to FIG. 1, this optical pickup comprises a linearly polarized semiconductor laser (LD) 1, a collimator lens 2, a polarization beam splitter 3, a 1/4
It comprises a wave plate 4, an objective lens 5, a condenser lens 6, and a photodiode (PD) 7. In addition,
Although the optical pickup actually has optical components for focus detection and track detection, they are not shown in FIG. Further, as the information recording / reproducing medium 9 on which information is recorded and reproduced by the optical pickup, for example, a medium on which information is recorded with a difference in reflectance is used.

In such a configuration, light emitted from the LD 1 (light having a polarization parallel to the paper surface) is converted into parallel light by a collimator lens 2, and then the parallel light is split into a polarizing beam splitter 3 and a quarter-wave plate. The light is changed from linearly polarized light to circularly polarized light through an optical isolator constituted by 4, and is recorded via an objective lens 5 in an information recording / reproducing medium (optical memory (optical disk, etc.)) 9
And is reflected by the surface of the information recording / reproducing medium 9.
Then, when this light is reflected by the surface of the information recording / reproducing medium 9, the turning direction of the circularly polarized light changes. Therefore, when the reflected light passes through the ４ wavelength plate 4, the reflected light becomes polarized light perpendicular to the paper surface.
The light is reflected by the condenser lens 6 and condensed by the condenser lens 6 and enters the PD 7.

In the above configuration, the spot size on the surface of the information recording / reproducing medium 9 can be obtained only up to about the wavelength of light due to the diffraction limit of light. That is, the spot size w on the surface of the information recording / reproducing medium 9 can be expressed by the following equation.

[0005]

(Equation 1)

Here, θ ′ is the emission angle of the objective lens 5, and NA (numerical aperture) of the objective lens 5 and NA = sin
There is a relationship of θ '. Λ is the wavelength of the light emitted from LD1. As can be seen from Equation 1, the information recording / reproducing medium 9
The spot size w on the surface can be obtained only up to about the wavelength of light.

Therefore, Japanese Patent Laid-Open No. Hei 5-189796 discloses that
A configuration in which another hemispherical lens (solid immersion lens) is inserted between the objective lens 5 and the information recording / reproducing medium 9 as in a liquid immersion method of a microscope to increase the effective NA (numerical aperture). Technology has been proposed. FIG.
(A) and (b) show a configuration in which another hemispherical lens (solid immersion lens) 10 is inserted between the objective lens 5 and the information recording / reproducing medium 9.

2A, the solid immersion lens 10 is brought close to the information recording / reproducing medium 9 at a distance equal to or shorter than the wavelength, so that the spot size of the light condensed on the end face of the lens 10 is reduced. This is based on the fact that it is proportional to the reciprocal of the refractive index of 10, and if the refractive index of the lens 10 is n, the spot size w 'on the surface of the information recording / reproducing medium 9 is as follows.

[0009]

(Equation 2)

In the case where the shape of the solid immersion lens 10 is a super hemispherical lens as shown in FIG.
Since Snell's law is applied on the surface of the solid immersion lens 10, the spot size w 'can be further reduced as in the following equation.

[0011]

(Equation 3)

When the objective lens 5 and the solid immersion lens 10 are integrated on a substrate, when the refractive index of the substrate is n ₁ and the refractive index of the solid immersion lens is n ₂ , the spot size w ′ is Equations 4 and 5) are obtained.

[0013]

(Equation 4)

[0014]

(Equation 5)

Here, Equation 4 is a case where the solid immersion lens 10 is a hemisphere as shown in FIG. 2A, and Equation 5 is a case where the solid immersion lens 10 is a super hemisphere as shown in FIG. 2B. .

However, in the above configuration, the distance between the information recording / reproducing medium 9 and the solid immersion lens 10 must be close to about 100 nm, which is smaller than the wavelength of light. Therefore, the document "USP 5,497,35
9 or BDTerris, HJ Mamin, and D. Rugar, “Near fi
eld optical data strage ”, Appl.Phys.Lett., 68, No.2,
141, 1996 ", a flying head 21 as shown in FIG. 3 is proposed. The flying head 21 is provided with a solid immersion lens 10 (radius r = 0.5 mm, refractive index n = 1.83) on the slider 20 by bonding, and is further separated from the solid immersion lens 10 by a predetermined distance. An objective lens 5 (NA = 0.5) is provided.
The flying head 21 is held by a suspension 19.

In this configuration, a spot size of 360 nm is obtained using a light source having a wavelength of 830 nm. In a conventional information recording / reproducing medium (such as an optical disk), light condensed from the objective lens 5 accesses a recording layer through a transparent substrate having a certain thickness, whereas a solid immersion lens 10 is used. Since the recording layer of the information recording / reproducing medium (such as an optical disk) 9 must be located at a position close to the solid immersion lens 10, the information recording / reproducing medium 9 has a recording layer It is necessary to use an information recording / reproducing medium having no substrate between itself and the lens 10 or having an extremely thin protective layer on the surface.

In order to move the flying head 21 to a target position on the information recording / reproducing medium 9 (optical disk) 9, the flying head 21 is fixed to the tip of a swing arm 20, as shown in FIG. The arm 20 is moved to the information recording / reproducing medium 9
A configuration has been proposed in which it is moved in parallel to the plane of FIG.

FIG. 5 shows the fixed optical system 30 and the movable optical system 31 in the configuration of FIG. Here, the fixed optical system 30 includes a collimating portion, a portion for detecting an information signal, a tracking signal, and the like. In contrast, the movable optical system 31 has mirrors 23, 2
4, an objective lens 5, a solid immersion lens 10 and the like are provided, and mirrors 23 and 24, the objective lens 5, the solid immersion lens 10 and the like are installed on a swing arm 20, and the mirror 23 is connected to the swing arm 20.
It is installed on the rotating shaft part.

In the configuration shown in FIG. 4 and FIG.
1 is derived as follows. That is, the laser light is sent from the fixed optical system 30 to the mirror 24 on the floating head 21 via the mirror 23 installed near the rotation axis of the swing arm 20, and is reflected there and sent to the floating head 21. Can be

[0021]

However, in the conventional information recording / reproducing apparatus, as shown in FIG. 5, the fixed optical system 30 and the movable optical system 31, which are the optical system of the swing arm 20 and the flying head 21, are provided. However, although the movable optical system 31 is small, the size of the fixed optical system 30 is large, which is not effective in reducing the size of the entire apparatus.

Further, in a portion where the fixed optical system 30 and the movable optical system 31 are connected, since the swing arm 20 is twisted, the optical axis may be shifted.
Further, the solid immersion lens 10 and the objective lens 5
Are not integrated, it is necessary to accurately align the positions of the two lenses 10 and 5, so that there is a limit in performing stable recording and reproduction.

An object of the present invention is to provide an information recording / reproducing apparatus using a swing arm and a flying head, which can reduce the size of the entire apparatus and can shorten the access time. And

[0024]

According to one aspect of the present invention, there is provided an information recording / reproducing apparatus for recording / reproducing information on / from an information recording / reproducing medium, comprising at least a head unit. And an arm unit, and a rotation driving unit that supports the arm unit and rotationally drives the arm unit, wherein the arm unit is provided with a fixed optical system composed of micro optical components. .

According to a second aspect of the present invention, in the information recording / reproducing apparatus according to the first aspect, the fixed optical system provided on the arm portion includes at least a laser light source for emitting a laser beam, and a light receiving element. , Signal detection means.

According to a third aspect of the present invention, in the information recording / reproducing apparatus according to the first aspect, the head portion is configured as a monolithic head in which a solid immersion lens and an objective lens are formed on one substrate. It is characterized by having.

According to a fourth aspect of the present invention, in the information recording / reproducing apparatus according to the first aspect, the head section includes a solid immersion lens and an objective lens formed on a plurality of substrates, and the plurality of substrates are bonded to each other. It is characterized in that it is configured as an integrated monolithic head.

According to a fifth aspect of the present invention, in the information recording / reproducing apparatus according to the first aspect, the fixed optical system provided in the arm portion is provided with a head position detecting means. Features.

According to a sixth aspect of the present invention, there is provided the information recording / reproducing apparatus according to the first aspect, wherein the fixed optical system provided on the arm and the head are optically coupled. Optical means is provided.

According to a seventh aspect of the present invention, in the information recording / reproducing apparatus according to the sixth aspect, the coupling optical means includes:
It is characterized in that it has a function of deflecting the angle of light incident on the head section.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 6 is a diagram showing a configuration example of the information recording / reproducing apparatus according to the present invention. Referring to FIG. 6, in this information recording / reproducing apparatus, a swing arm (arm portion) 42 is supported by a rotation drive device (rotation drive means) 41, and a fixed optical system 43 is provided on the swing arm 42. ing. A floating head (head unit) 44 is arranged on the swing arm 42 via a connecting means 45.

Here, the flying head 44 is configured to float on the information recording / reproducing medium 9 such as an optical disk, so that light propagates between the flying head 44 and the swing arm 42. . Further, as the connection means 45, a suspension such as a spring or a structure which does not shift the optical axis is used. In particular, since the optical system has a portion that acts as an isolator, the direction of light oscillation also becomes a problem. Therefore, it is preferable that the flying head 44 and the swing arm 42 be fixed so as not to be twisted.

FIG. 7 shows a configuration example of the fixed optical system 43 provided on the swing arm 42. FIG.
In the example, the fixed optical system 43 includes three transparent substrates 51,
52 and 53 are provided. The substrate 51 is provided with an optical system including a semiconductor laser 54 (a type enclosed in a can) and two mirrors 55 and 56. The substrate 52 is provided with a collimator lens 57 and a condenser lens 58.
, Mirror 59, polarization beam splitter 60, λ /
An optical system composed of four plates 61 is provided, and an optical system composed of two mirrors 62 and 63 and a photodiode 64 is provided on the substrate 53.

That is, the substrate 52 is provided with an optical element that mainly transmits light. The substrate 51 and the substrate 5
3 is provided with only a reflection optical element and an optical semiconductor element, whereby a photodiode substrate, that is, a Si substrate can be used as the substrate 53, and a laser substrate is used as the substrate 51. That is, a compound semiconductor substrate can be used. In this case, the semiconductor laser 54
7 may be the same as that shown in FIG. 7 if it is a surface-emitting type semiconductor laser. However, in the case of an edge-emitting type semiconductor laser, the light is emitted in the horizontal direction with respect to the substrate 51. In the case of a laser, a 45 ° mirror is preferably formed on the substrate 51 and emitted in a direction perpendicular to the substrate 51. At this time, since the reflectance of light may be low depending on the substrate 51, a material having a high reflectance such as Al may be vapor-deposited on the reflection surface at that time. Also,
The substrate between the mirrors of the substrate 51 and the substrate 53 may be removed in consideration of light use efficiency.

As described above, each optical system provided on each of the substrates 51, 52, and 53 is provided with a corresponding one of the substrates 51, 52, and 53.
53 are bonded together to form one optical system, that is, a fixed optical system 43.

Each optical element used in this embodiment is a minute element (small optical component) of mm or less. Therefore, the optical element may be configured using individual components, but can be manufactured on one substrate by a micro-optical element manufacturing technique using a semiconductor process. According to this, the accuracy of the position can be obtained with an accuracy similar to that of the semiconductor process. When the substrates 51, 52, and 53 are bonded, a mark for positioning may be prepared in advance. Further, the substrate 52 may be a substrate obtained by bonding two transparent substrates. In this case, for bonding the two transparent substrates, a resin adhesive or anodic bonding can be used. Further, the front and rear of the lenses 57 and 58 may be hollow.

Further, in the example of FIG. 7, a heat sink 66 is arranged on the semiconductor laser 54 provided on the substrate 51. When a semiconductor laser 54 enclosed in a can is used, the substrate 51
If the shape of the can is formed, the arrangement of the semiconductor laser 54 can be facilitated. In the configuration of FIG. 7, a prism for shaping the beam from the semiconductor laser 54 is not provided.
Is a toroidal lens, so that the semiconductor laser 54
Can be shaped.

FIG. 8 shows a configuration example of the flying head 44. In the example of FIG. 8, the flying head 44 has an objective lens 84 disposed on one surface of a transparent substrate 83,
A solid immersion lens 85 is provided on the other surface of the substrate 83.
Are arranged. Here, the two lenses 84 and 85 are arranged so that the optical axis X matches. In the example of FIG. 8, the solid immersion lens 85 is a hemispherical lens. At this time, it is assumed that the objective lens 84 has an aspheric surface and a refractive index of n1, the solid immersion lens 85 has a radius of r1 and a refractive index of n2, and the substrate 83 has a refractive index of n0. The solid immersion lens 85 is arranged so that the center of the solid immersion lens 85 is located at the focal position of the objective lens 84.

When recording or reproducing a signal on or from the information recording / reproducing medium 9, the flying head 44
It is designed to float above at a distance less than the wavelength of light,
A fine structure may be formed on the surface of the flying head 44 with respect to the information recording / reproducing medium 9, that is, the surface on the side of the solid immersion lens 85, so that a stable flying distance is obtained. Further, the objective lens 84 may be a spherical surface instead of an aspheric surface. Further, the solid immersion lens 85
May be a super hemisphere. Further, a second solid immersion lens can be provided inside the solid immersion lens 85.

FIG. 9 shows another example of the structure of the flying head 44. In the configuration example of FIG.
Reference numeral 4 denotes a monolithic substrate obtained by bonding substrates on which two lenses are formed. That is, in the flying head 44 of FIG. 9, the first surface 91 of the objective lens is disposed on one surface of the first substrate 90, the second surface 92 of the objective lens is disposed on one surface of the second substrate 93, A solid immersion lens 94 is arranged on a surface opposite to the second substrate 93. That is, in the example of FIG.
It is composed of two refraction surfaces 91 and 92. In addition, the three lenses 91, 92, and 94 are arranged so that the optical axes X coincide. Further, in the example of FIG. 9, the two surfaces 91 and 92 of the objective lens are aspherical, and the solid immersion lens 94 is a hemispherical lens. At this time, the refractive index of the objective lens is n1, the radius of the solid immersion lens 94 is r1, and the refractive index is n2,
The refractive indices of the substrates 90 and 93 are n1. Further, the solid immersion lens 94 is arranged so that its center is located at the focal position of the objective lenses 91 and 92.

When recording or reproducing a signal on or from the information recording / reproducing medium 9, the flying head 44 moves the information recording / reproducing medium 9.
It is designed to float above at a distance less than the wavelength of light,
A fine structure may be formed on the surface of the flying head 44 with respect to the information recording / reproducing medium 9, that is, the surface on the side of the solid immersion lens 94 so that a stable flying distance is obtained. Also, the first surface 91 or the second surface 9 of the objective lens
2 may be a spherical surface instead of an aspheric surface. Further, the solid immersion lens 94 may be a super hemisphere. Further, a second solid immersion lens can be provided inside the solid immersion lens 94.

In the example of FIG. 9, two substrates 90, 9
In order to precisely position 3, the substrates 90,
Small grooves 95 and 96 are provided on the surface of 93, respectively. Each of the grooves 95 and 96 has a spherical surface.
By fitting the 93, the two substrates 90 and 93 can be precisely positioned. In particular, in this example, the groove 9
Since 5,96 are spherical, with accurate position accuracy,
Objective lenses 91 and 92 and solid immersion lens 9
4 can be aligned with the optical axis X. Further, the lens 9
The distance between the lenses 1 and 92 and the lens 94 can also be accurately adjusted. In addition, as the minute sphere 97, a sphere having little variation, for example, used as a spacer of a liquid crystal can be used.

In the above example, in order to precisely position the two substrates 90 and 93, minute grooves 95 and 96 are provided on the surfaces of the substrates 90 and 93 to be bonded, respectively.
The two substrates 90 and 93 were precisely positioned by inserting the minute spheres 97 into the 96 and fitting the two substrates 90 and 93, but other means for precisely positioning the two substrates 90 and 93 include other means. Various means may be used. For example, alignment marks used in a semiconductor process are provided on the surface of each substrate (marks are patterned on the surface of the substrate), and the two substrates 9 are observed while observing with a microscope.
The positions of 0 and 93 can also be adjusted. If an alignment mark is used, the optical axis can be aligned with an accuracy on the order of μm. Further, for example, by providing an uneven structure on each substrate and fitting the uneven structure, the positions of the two substrates 90 and 93 can be adjusted.

FIG. 10 shows a connection example between the fixed optical system 43 and the flying head 44. In the example of FIG. 10, the fixed optical system 43 of FIG. 7 is mounted on the swing arm 42, and the swing arm 42 has a connection unit 45.
The flying head 44 is arranged via (for example, a suspension). The movable mirror 7 as a coupling optical unit for optically coupling the fixed optical system 43 and the flying head 44 is provided in a direction in which light is emitted from the fixed optical system 43.
1 is installed, and light from the fixed optical system 43 is
1 and enters the flying head 44, where the objective lens (84 in the example of FIG. 8 and 91 and 92 in the example of FIG. 9) and the solid immersion lens (FIG.
In the example of FIG. 9, the light is condensed at 85) and in the example of FIG. 9, the light is incident on the information recording / reproducing medium 9.

The signal light from the information recording / reproducing medium 9 is supplied to the objective lens (84 or 91, 9) of the flying head 44.
2) The light is directed to the movable mirror 71 via the solid immersion lens (85 or 94), is reflected by the movable mirror 71, and enters the fixed optical system 43. The flying head 44 floats on the information recording / reproducing medium 9,
The attitude of the flying head 44 may be inclined due to the rotation speed of the information recording / reproducing medium 9, the surface roughness of the information recording / reproducing medium 9, and the like. Even at that time, the movable mirror 71 is
It is necessary to have a function of finely adjusting the reflection angle so that light always enters at a constant angle. Fine adjustment of the reflection angle at the movable mirror 71 is performed by rotating the movable mirror 71 with a piezoelectric element or moving the movable mirror 71 with electrostatic force.

FIGS. 11A and 11B show an example of the configuration of a movable mirror 71 having a function of finely adjusting the reflection angle. FIGS. 11A and 11B are exploded views of the movable mirror 71, and the structure of FIG. 11A is arranged on the structure of FIG. 11B. FIG. 11 (a),
In (b), 71a is a post for mounting the mirror surface of 71b. This post 71a has a mirror surface 7
Attach hinge portions 71c on both sides of 1b. In the examples shown in FIGS. 11A and 11B, the movable mirror 71 is provided with electrodes 73a and 73b to which a voltage for adjusting the reflection angle is applied, and the voltage is applied to the electrodes 73a and 73b to cause electrostatic force. Occurs, and the mirror surface 71 of the movable mirror 71
The structure is such that b is drawn to the electrode side and rotated by the deformation of the hinge 71c.

In this case, in order to detect the attitude of the flying head 44, four minute mirrors 74 are provided on the movable mirror 71 side of the flying head 44 as shown in FIG.
a, 74b, 74c, and 75d are provided.

FIG. 13 shows a specific example of the connection between the fixed optical system 43 and the flying head 44, that is, the movable mirror 71. In the example of FIG. 13, the movable mirror 71 of FIG. 12 includes an active diffraction grating 80 and a fixed mirror 81.

That is, the active diffraction grating 80 is provided in the direction of light emission of the fixed optical system 43, and the light from the fixed optical system 43 is diffracted by the active diffraction grating 80.
The flying head 44 is deflected and reflected by the fixed mirror 81.
The signal light from the flying head 44 (the signal light from the information recording / reproducing medium 9) is reflected by the fixed mirror 81, deflected by the active diffraction grating 80, and
3. Here, even when the attitude of the flying head 44 may be inclined due to the rotation speed of the information recording / reproducing medium 9 or the surface roughness of the information recording / reproducing medium 9, the active diffraction grating 80 always has a constant angle to the flying head 44. Has a function of finely adjusting the deflection angle so that light from the fixed optical system 43 is incident.

The active diffraction grating 80 includes:
For example, an acousto-optic effect element can be used. The acousto-optic effect is such that when an ultrasonic wave is poured into a medium, a compressional wave having a refractive index is generated by a photoelastic effect, and the compressional wave can be used as a diffraction grating. Is changed, the diffraction angle can be changed. The active diffraction grating 80 has a transmitted light component, and this transmitted light component can be used for detecting the attitude of the flying head 44.

Next, the operation of the information recording / reproducing apparatus having such a configuration will be described. First, in FIG. 6, before the information recording / reproducing medium 9 rotates, the swing arm 42 stands by at a home position (a position not affected by disturbance or the like). When the information recording / reproducing medium 9 rotates and enters a recordable or reproducible state, the rotation arm 41 moves the swing arm 42 to a designated position. At this time, the flying head 44 floats from the information recording / reproducing medium 9 by aerodynamic action. Upon reaching the target position, a signal can be recorded or reproduced on the information recording / reproducing medium 9 with a change in light intensity or a magnetization direction.

More specifically, when the fixed optical system 43 provided on the swing arm 42 is as shown in FIG. 7, the light from the semiconductor laser 54 of the fixed optical system 43 propagates as follows. That is, the divergent light emitted from the semiconductor laser 54 becomes parallel light by the collimator lens 57, and the parallel light is reflected by the left and right mirrors 62 and 63 of the substrate 53 and enters the polarization beam splitter 60 of the substrate 52. The polarization beam splitter 60 reflects or transmits light depending on the polarization state of the light. In the example of FIG. 7, it is assumed that polarized light in the horizontal direction with respect to the paper surface is reflected, and polarized light in the front-back direction is transmitted. Since the laser light from the mirror 63 is polarized in the horizontal direction, the laser light is reflected by the polarization beam splitter 60 and is incident on the λ / 4 plate 61, so that the optical system of the flying head 44 (the objective lens (84 or 91, 92), The light enters the information recording / reproducing medium 9 from a solid immersion lens (85 or 94). Thereafter, the signal light from the information recording / reproducing medium 9 is transmitted to the optical system of the flying head 44 (the objective lens (84 or 9)).
1,92), solid immersion lens (85 or 9)
4)), the light is incident on the λ / 4 plate 61, becomes polarized in the front-back direction with respect to the paper surface by the λ / 4 plate 61, passes through the polarization beam splitter 60, and is reflected by the mirror 59 of the substrate 52.
The light is reflected by the two mirrors 56 and 55 of the substrate 51, enters the condenser lens 58 of the substrate 52, becomes converged light by the condenser lens 58, and enters the photodiode 64.

When the flying head 44 is configured as shown in FIG. 8, when recording information on the information recording / reproducing medium 9, the collimated light from the fixed optical system 43 enters the objective lens 84, where it is converged. And enters the solid immersion lens 85. The convergent light that has entered the solid immersion lens 85 has a minute spot size on the bottom surface of the solid immersion lens 85 due to the above-described operation, and the information recording / reproducing medium 9 in the proximity position
And recording on the information recording / reproducing medium 9 is performed.

When the flying head 44 is configured as shown in FIG. 9, when recording information on the information recording / reproducing medium 9, the collimated light from the fixed optical system 43 is incident on the first surface 91 of the objective lens. Then, the light is refracted here, enters the second surface 92 of the objective lens of another substrate, becomes further refracted and converges, and enters the solid immersion lens 94. The convergent light that has entered the solid immersion lens 94 has a minute spot size on the bottom surface of the solid immersion lens 94 due to the above-described action, and reaches the information recording / reproducing medium 9 at a close position.
Recording on the information recording / reproducing medium 9 is performed. When reproducing the information recorded on the information recording / reproducing medium 9,
When light from the fixed optical system 43 enters the mark on the information recording / reproducing medium 9, the reflected light travels in the opposite direction to the incident light, returns to the fixed optical system 43, and is reflected by the fixed optical system 43. By detecting changes in the signal and reading the signal,
Reproduction is performed.

The structure of the movable mirror 71 is as shown in FIGS. 10, 11 (a) and 11 (b).
When the mirror 4 is as shown in FIG.
The rotation of 1 is performed by detecting the attitude of the flying head 44 from the signal light returned from the flying head 44 on the detection system side of the fixed optical system 43. Specifically, the light intensity from the mirrors 74a, 74b, 74c, and 75d of the flying head 44 is detected by the photodiode 64 (specifically, an arrayed photodiode) of the fixed optical system 43, and an arithmetic unit (shown in FIG. ), Each mirror 74a, 74b, 74c,
By detecting the light intensity difference from 75d, the attitude of the flying head 44, that is, the amount of tilt angle of the flying head 44 from the normal position is calculated (the attitude of the flying head 44 is detected). As described above, the tilt angle amount is calculated by the arithmetic unit, and the calculated tilt angle amount is converted into a voltage amount applied to the electrodes 73a and 73b to rotate the movable mirror 71. Thus, even if the attitude of the flying head 44 changes, light can be accurately incident on the flying head 44, and stable recording and reproduction can be performed.

As described above, in the present invention, by providing the fixed optical system 43 composed of micro optical components on the swing arm 42, the size of the entire apparatus can be reduced. Here, the fixed optical system 43 includes at least a laser light source 54 that emits laser light, a light receiving element 64, and signal detection means.

In the present invention, the flying head 44 is configured as a monolithic head in which a solid immersion lens 85 and an objective lens 84 are formed on one substrate as shown in FIG. , The solid immersion lens 94 and the objective lens 9
1 and 92 are formed on a plurality of substrates 90 and 93, and the plurality of substrates 90 and 93 are bonded together to form a monolithic head. As described above, by employing a monolithic head as the flying head 44, the weight of the flying head 44 can be reduced. Further, since the solid immersion lens and the objective lens are made monolithic, the alignment of the optical axis becomes unnecessary, and the apparatus can be simplified, the number of manufacturing steps can be reduced, and the cost can be reduced.

In the present invention, the swing arm 42
The floating optical system 43 is provided with a floating head 44.
Is provided, and coupling optical means 71 is provided for optically coupling between the fixed optical system 43 provided on the flying arm 44 and the flying head 44, and the coupling optical means is provided. 71 has a function of deflecting the angle of light emitted to the flying head 44 in accordance with the attitude of the flying head 44 detected by the attitude detecting means, so that even if the attitude of the flying head 44 changes. Light can be accurately incident on the flying head 44, and stable recording and reproduction can be performed.

[0059]

As described above, according to the first to seventh aspects of the present invention, the head, the arm,
In an information recording / reproducing apparatus having a rotation driving means for supporting the arm section and rotating the arm section, the entire information recording / reproducing apparatus is reduced in size by providing a fixed optical system composed of micro optical components in the arm section. Can be

In particular, according to the third and fourth aspects of the present invention, the weight of the head portion can be reduced by forming the head portion as a monolithic head. Also,
By making the solid immersion lens and the objective lens monolithic, the alignment of the optical axis becomes unnecessary, the apparatus can be simplified, the number of manufacturing steps can be reduced, and the cost can be reduced.

According to the fifth, sixth, and seventh aspects of the present invention, the head attitude detecting means is provided, and furthermore, a coupling for optically coupling with the fixed optical system head is provided. Since the optical unit has a function of deflecting the angle of light incident on the head unit, the light can be accurately incident on the head unit even when the attitude of the head unit changes. Reproduction can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a conventional optical pickup.

FIG. 2 is a diagram showing a configuration example in which a solid immersion lens is inserted between an objective lens and an information recording / reproducing medium.

FIG. 3 is a diagram illustrating a configuration example of a conventional flying head.

FIG. 4 is a diagram showing a configuration example of a conventional information recording / reproducing apparatus using a swing arm and a flying head.

FIG. 5 is a diagram showing a configuration example of a fixed optical system and a movable optical system in the configuration of FIG. 4;

FIG. 6 is a diagram showing a configuration example of an information recording / reproducing apparatus according to the present invention.

FIG. 7 is a diagram illustrating a configuration example of a fixed optical system provided in a swing arm.

FIG. 8 is a diagram illustrating a configuration example of a flying head.

FIG. 9 is a diagram showing another configuration example of the flying head.

FIG. 10 is a diagram illustrating a connection example between a fixed optical system and a flying head.

FIG. 11 is a diagram illustrating a configuration example of a movable mirror having a function of finely adjusting a reflection angle.

FIG. 12 is a diagram showing four mirrors provided on a flying head.

FIG. 13 is a diagram illustrating a specific example of a movable mirror that is a connection between a fixed optical system and a flying head.

[Explanation of symbols]

 Reference Signs List 9 information recording / reproducing medium 41 rotation driving device 42 swing arm 43 fixed optical system 44 floating head 45 connection means 51, 52, 53 substrate 54 semiconductor laser 55, 56 mirror 57 collimating lens 58 light collecting lens 59 mirror 60 polarizing beam splitter 61 λ / 4 plate 62, 63 mirror 64 photodiode 66 heat sink 71 movable mirror 73a, 73b electrode 71a, 71b mirror surface 74a, 74b, 74c, 74d mirror 80 active diffraction grating 81 fixed mirror 83 substrate 84 objective lens 85 solid immersion lens 90 First substrate 93 Second substrate 91 First surface of objective lens 92 Second surface of objective lens 94 Solid immersion lens 95, 96 Groove 97 Sphere

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D118 AA01 AA11 BA01 BB02 BD01 BD05 BF02 BF03 CD03 DA28 DC03 EB02 EF09 FA08 5D119 AA01 AA08 AA11 AA22 BA01 CA06 DA01 DA05 DA11 EA02 JA43 JA44 JA52 JB03 MA05 MA06

Claims (7)

[Claims] 1. An information recording / reproducing apparatus for recording / reproducing information on / from an information recording / reproducing medium, comprising at least a head unit, an arm unit, and a rotary drive for supporting the arm unit and rotating the arm unit. Means, wherein the arm section is provided with a fixed optical system composed of micro optical components. 2. The information recording / reproducing apparatus according to claim 1, wherein the fixed optical system provided on the arm unit includes at least a laser light source that emits a laser beam, a light receiving element, and signal detection means. An information recording / reproducing apparatus characterized in that: 3. The information recording / reproducing apparatus according to claim 1, wherein the head section is configured as a monolithic head in which a solid immersion lens and an objective lens are formed on one substrate. Information recording and playback device. 4. The information recording / reproducing apparatus according to claim 1, wherein the head section is a monolithic head in which a solid immersion lens and an objective lens are formed on a plurality of substrates, and the plurality of substrates are integrated by bonding. An information recording / reproducing apparatus characterized by being constituted. 5. The information recording / reproducing apparatus according to claim 1, wherein the fixed optical system provided in the arm section is provided with a head section attitude detecting means. . 6. The information recording / reproducing apparatus according to claim 1, wherein coupling optical means is provided for optically coupling between a fixed optical system provided on said arm section and a head section. An information recording / reproducing apparatus characterized in that: 7. The information recording / reproducing apparatus according to claim 6, wherein the coupling optical means has a function of deflecting an angle of light incident on the head unit.