JP2003115120A - Information recording/reproducing device, optical system and optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording/reproducing device, in which the high recording density for a recording medium and the highly accurate tracking control are attainable, and also to provide an optical system and optical element suitable therefor. SOLUTION: A recording/reproducing light DL is converged on a minute opening 19H which is formed on a thin film 19 located at an almost center of a flat surface part 18U of an immersion lens SIL formed by a medium having the high refractive index, to generate a near-field light NP1 for the recording/ reproducing operation, then minute recording pits DP are formed on land part 20L. The size of the thin film 19 is made a little larger than that of a spot of the recording/reproducing light DL. Tracking light TL is totally reflected at the position where no thin film 19 exists in the flat surface part 18U, being the nearest position to the minute opening 19H. Then a tracking spot TS over the groove part 20G is made to be minute for generating a near-field light NP2 for tracking, and the recording/reproducing position becomes near to the tracking position in the recording medium 20, then the highly accurate tracking and the high density recording are attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus using near-field light, its optical system and optical element.

[0002]

2. Description of the Related Art In an information recording / reproducing apparatus which is an apparatus for recording information on a recording medium and / or reproducing (reading) information from the recording medium by using light, the recording capacity of the recording medium is increased. Therefore, it is necessary to improve the recording density. For that purpose, it is conceivable to reduce the recording spot, which is a unit for recording information, and increase the recording density in two directions, that is, the circumferential direction and the radial direction of the disc-shaped disk. For example, when near-field light is used as the recording / reproducing light, the recording spot can be made smaller, so that the recording density can be improved.

In order to improve the recording density by reducing the recording spot, it is necessary to record the information at an accurate position on the recording medium and read the recorded information from the accurate position for reproduction. . Therefore, there is a need for a technique of accurately positioning an optical head including an optical element on the recording medium to perform tracking control.

As a technique for improving the tracking accuracy when the near-field light is used for such recording and reproduction, for example, there is a technique disclosed in Japanese Patent Laid-Open No. 7-192280. By arranging the scanning control head including the system in parallel with the scanning head that performs recording and reproduction by the near-field light, the scanning head can be accurately tracked to a predetermined position on the recording medium. But,
If the distance between the scanning head and the scanning control head is integrally changed due to thermal expansion or contraction of the member, or if the rigidity of the connecting member is low, the scanning head vibrates during tracking and the vibration Problems such as not being reflected in tracking control occur.

In order to solve this problem, for example, there is a technique disclosed in Japanese Patent Laid-Open No. 2001-110070, in which the near-field light for recording / reproducing and the propagating light for tracking having different wavelengths are the same. Since it is emitted from the near-field light generating member of, the above-mentioned, since the scanning head and the scanning control head are separated, the tracking failure due to the deviation of the correlation between the scanning head and the scanning control head does not occur, Stable and highly accurate tracking can be performed.

[0006]

However, here, a solid immersion lens or the like is used as the near-field light generating member,
Although the recording spot due to the near-field light is made small by shortening the wavelength, it is impossible to obtain a small recording spot exceeding the diffraction limit.

In view of the above problems, the present invention makes it possible to reduce the recording spot due to the near-field light to improve the recording density of the recording medium and to perform tracking control on the recording medium with high accuracy. It is an object of the present invention to provide an information recording / reproducing apparatus and a technique relating to an optical system and an optical element suitable for the information recording / reproducing apparatus.

[0008]

In order to solve the above problems, the invention of claim 1 uses near-field light to record information on a recording medium having a tracking pattern or to record information on the recording medium. An information recording / reproducing apparatus for reproducing information, comprising: (a) a light supply means for supplying first and second light; and (b) recording information on the recording medium or recording on the recording medium. A first near-field light for recording / reproducing for reproducing the recorded information based on the first light;
And an optical element having a second region for generating near-field light for tracking for detecting the tracking pattern based on the second light.

According to a second aspect of the present invention, in the information recording / reproducing apparatus according to the first aspect, a minute opening for generating the near-field light for the recording / reproducing is provided in the first area. Has been formed.

Further, the invention of claim 3 is the information recording / reproducing apparatus according to claim 1 or 2, wherein the near-field light for tracking is in the second region, It is generated by totally reflecting the second light.

The invention according to claim 4 is the information recording / reproducing apparatus according to claim 1 or 2, wherein the near-field light for tracking is generated in the second area. A minute opening is formed to allow it.

Further, the invention of claim 5 is the information recording / reproducing apparatus according to any one of claims 1 to 4, wherein the first area and the second area overlap each other. Do not fit.

According to a sixth aspect of the present invention, in the information recording / reproducing apparatus according to the fifth aspect, the light supply unit supplies the first light to the optical element, and the second angle. An optical adjusting unit that relatively changes the angle at which light is applied to the optical element.

According to a seventh aspect of the present invention, in the information recording / reproducing apparatus according to the fifth aspect, the optical supply means changes the incident angle of the second light to the optical element stepwise. By so doing, the optical adjustment means is provided that can change the relative positional relationship between the first area and the second area in stages to a plurality of positional relationships.

Further, the invention of claim 8 is an optical system used for producing an optical action with a recording medium having a tracking pattern, wherein information is recorded or recorded on the recording medium. A first area in which a minute opening is formed for generating near-field light for recording / reproduction for reproducing information recorded on a recording medium based on the first light; A second region that is provided externally and that totally reflects the second light to generate near-field light for tracking for detecting the tracking pattern; and guides the first light to the minute aperture, A single light collection element that directs the second light to the second region.

According to a ninth aspect of the invention, there is provided an optical element used for producing an optical action with a recording medium having a tracking pattern, wherein information is recorded on the recording medium or the information is recorded on the recording medium. A first area in which a minute aperture for generating recording / reproducing near-field light for reproducing information recorded on a recording medium is formed, and a tracking near-field for detecting the tracking pattern. And a second region in which a minute opening for generating light is formed.

According to a tenth aspect of the present invention, there is provided an optical element used for producing an optical action with a recording medium having a tracking pattern, the main body being formed of a high refractive index medium, A minute opening is formed for generating near-field light for recording / reproducing for recording information on the recording medium or reproducing the information recorded on the recording medium based on the first light. A first region and a second region which is provided outside the first region and totally reflects the second light to generate near-field light for tracking for detecting the tracking pattern. .

Correspondence between the invention of each claim and each embodiment described later is as follows when seen in the drawings (only the drawing peculiar to each embodiment is pointed out).

Invention of Claim 1 ... FIGS. 8 to 34.

Invention of Claim 2 ... FIGS. 8 to 34.

Invention of Claim 3 ... FIGS. 8 to 14 and 18
-FIG. 24, FIG. 30-FIG. 34.

Invention of Claim 4 ... FIGS. 15 and 16.

Invention of Claim 5: FIGS. 8 to 14 and 1
6, FIG. 17, and FIGS. 20 to 29.

Invention of Claim 6 ... FIGS. 6, 7, 9, and 10.

Invention of Claim 7: FIG. 6, FIG. 7, FIG.
FIG. 14.

Invention of Claim 8: FIGS. 8 to 14, 20
~ Figure 24.

Invention of Claim 9 ... FIG.

Invention of Claim 10: FIGS. 8 to 14 and 2
0 to 24, 30 to 34.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings.

<1. Example of Information Recording / Reproducing Device> First,
An information recording / reproducing apparatus using near-field light according to the present invention will be described. FIG. 1 is a diagram conceptually showing an information recording / reproducing apparatus A which is an example of an embodiment of the present invention.
The details are shown in FIG. 2 and FIG. 3 divided by the one-dot chain line DI.

The information recording / reproducing apparatus A includes a recording medium accommodating portion 4 for accommodating a disk-shaped recording medium 20, a near-field light generating device NE, and the near-field light generating device NE with respect to the recording medium 20. A near-field light generator driving device M that relatively moves in the radial direction of the, a tracking control unit CONT that controls the operation of the near-field light generator driving device M, and an external output device OS that outputs reproduced information. is doing.

The recording medium housing portion 4 has a support rotating body SP for the recording medium 20, and further has a rotation driving device (not shown) for rotating the support rotating body SP. As a result, the near-field light generator NE can move in the circumferential direction relative to the recording medium 20.

The near-field light generator NE is arranged in the vicinity of the recording medium 20 accommodated in the recording-medium accommodating portion 4, and is a solid immersion lens SIL as a typical example of an optical element for generating near-field light.
The case of using can be mentioned. Therefore, here, the recording / reproducing light DL for generating the near-field light NP1 and NP2 for irradiating the recording medium 20 from the solid immersion lens SIL and the light generator 1 for obtaining the tracking light TL, and the tracking light A tracking light adjusting section 2 for variously adjusting the use light and an optical element peripheral section 3 around the solid immersion lens SIL and the recording medium 20 are provided. In the present invention, the recording / reproducing light DL and the tracking light TL are propagating light,
Also referred to as “first light” and “second light”, the recording / reproducing light DL and the tracking light TL are finally optical elements such as the solid immersion lens SIL and are used for recording / reproducing and tracking proximity respectively. Also called "first light" and "second light" on the optical path until the field lights NP1 and NP2 are generated. That is, as will be described later, the recording / reproducing light D
Near-field light NP1 is generated from L (first light), and near-field light NP2 is generated from tracking light TL (second light).

The recording medium 20 has a tracking pattern for tracking control, and the tracking pattern is formed by the unevenness of the land portion 20L and the groove portion 20G, and the land portion 20L and the groove portion 20G are They are arranged in concentric circles or spirals alternately in the radial direction. Although not shown in the drawing, the recording medium 20 has the substrate on the side of the supporting rotary body SP and the recording layer on the side of the solid immersion lens SIL. The substrate is formed of a material such as SiO2 (silicon dioxide). Further, the recording layer may be formed of a material used for recording information, and for example, by irradiating a thin film of a photochromic molecule with light of a specific wavelength, optical characteristics such as absorptance of an irradiated portion are changed. By utilizing the nature of
Recording of digital information is performed. Further, at the time of reproduction, it is possible to reproduce (read) the recorded digital information by irradiating light of relatively weak intensity and detecting a change in absorption rate or the like.

The light generating section 1 includes a first laser diode 1
A first collimator lens 11 and a diffraction grating 12 are provided, and the first laser diode 1A is composed of a semiconductor laser or the like and generates a predetermined laser beam L1 for irradiating the recording medium 20. The laser light L1 from the first laser diode 1A is converted by the first collimator lens 11 into parallel light having a predetermined luminous flux width, and separated by the diffraction grating 12 into 0th-order light and 1st-order diffracted light. Here, the 0th-order light is the recording / reproducing light DL,
The first-order diffracted light is the tracking light TL. The recording / reproducing light DL and the tracking light TL reach the solid immersion lens SIL through separate optical paths. Here, as shown in FIG.
In order to obtain both the recording / reproducing light DL and the tracking light TL from only one light source, that is, the first laser diode 1A, the recording / reproducing light DL and the tracking light T
The wavelengths of L are the same, but the wavelength is not limited to this, and the recording / reproducing light DL and the tracking light TL are used.
One of them may be used as a different wavelength by wavelength conversion.

First, the optical path of the recording / reproducing light DL generated in the light generating section 1 to the solid immersion lens SIL will be described below. The recording / reproducing light DL generated in the light generator 1 is incident on the first beam splitter 13. The first beam splitter 13 has a polarization transmittance characteristic and transmits the P wave to the recording / reproducing light DL and reflects the S wave (P wave when the electric field vibration surface is in the plane of the drawing in the figure). At this time, the emitted light of the first laser diode 1A is horizontally polarized (see FIG.
Is arranged so that the vibration surface of the electric field is a wave within the plane of the drawing), and the first laser diode 1A and the first beam splitter 13 have
The positional relationship is such that it passes through the beam splitter 13.

The recording / reproducing light DL that has passed through the first beam splitter 13 consists of only the horizontal polarization component, and then passes through the quarter-wave plate 15. At this time, the recording / reproducing light DL consisting of only the horizontally polarized component becomes circularly polarized light. The circularly polarized recording / reproducing light DL enters the half mirror 16 and is half transmitted and half reflected by the semi-transparent surface 16A. The light that has passed through the half mirror 16 is converged by the first condenser lens 17 and is incident on the solid immersion lens SIL.

Next, the optical path of the tracking light TL generated by the light generator 1 to the solid immersion lens SIL will be described below. The tracking light TL generated in the light generator 1 enters the second beam splitter 21.
The second beam splitter 21 includes the first beam splitter 1
As in the case of 3, the P-wave transmits the tracking light TL and the S-wave reflects the tracking light TL. As described above, at this time, the first laser diode 1A is arranged so that the emitted light is horizontally polarized (a wave in which the vibration plane of the electric field is in the plane of the paper in FIG. 2).
A and the second beam splitter 21 are the tracking light T
There is a positional relationship in which L passes through the second beam splitter 21 in the state of the P wave.

The tracking light TL that has passed through the second beam splitter 21 is composed of only the horizontal polarization component, and then enters the tracking light adjusting section 2.

The tracking light adjusting section 2 comprises a quarter-wave plate 22, a total reflection mirror 25, and a shield plate 28. The tracking light TL that has entered the tracking light adjustment unit 2 first passes through the quarter-wave plate 22. At this time, the tracking light TL including only the horizontally polarized component becomes circularly polarized light. After the circularly polarized tracking light TL is reflected by the total reflection mirror 25, only the inner side of the light flux of the tracking light TL is shielded by the shielding plate 28, and only the outer edge of the light flux is tracked by the tracking light adjusting unit 2. Shoot out from. The shield plate 28 is made of, for example, Al, Ni,
A substantially disc-shaped plate made of a metal such as Cr may be used, and the tracking light TL after passing through the shield plate 28 becomes a cylindrical light. Although the total reflection mirror 25 is fixed here, the present invention is not limited to this, and various angles of the total reflection mirror 25 with respect to the tracking light TL can be set by a mechanism similar to the movable parallel plate 50 described later. The change may be made so that the optical path of the tracking light TL emitted from the tracking light adjusting unit 2 can be shifted.

The tracking light TL emitted from the tracking light adjusting section 2 is incident on the half mirror 16.
The semi-transmissive surface 16A transmits half and reflects half. The tracking light TL reflected by the half mirror 16 is made into convergent light by the first condenser lens 17, and is incident on the solid immersion lens SIL.

Here, the optical paths of the recording / reproducing light DL and the tracking light TL incident on the solid immersion lens SIL are deviated. The deviation of the optical path is adjusted by the installation angle of the total reflection mirror 25.

The recording / reproducing light DL incident on the solid immersion lens SIL generates near-field light NP1 for recording / reproducing in the solid immersion lens SIL, and generates a recording / reproducing spot on the land portion 20L of the recording medium 20. Recording pits DP are formed to record digital information. Also, the recording / reproducing optical DL
When the intensity of is relatively weaker than when the recording pit DP is formed, reflected light is generated on the land portion 20L of the recording medium 20. Details of the optical action of the recording / reproducing light DL in the optical element peripheral portion 3 including the solid immersion lens SIL and the recording medium 20 will be described later.

The light reflected on the land portion 20L of the recording medium 20 travels to the first beam splitter 13 substantially in the reverse optical path. Specifically, the light passes through the solid immersion lens SIL, passes through the condenser lens 17, and enters the half mirror 16. Then, the recording / reproducing light DL half-transmitted through the semi-transparent surface 16A of the half mirror 16 is incident on the quarter-wave plate 15. Here, since the recording / reproducing light DL that is incident on the quarter-wave plate 15 is once reflected by the recording medium 20, the polarization direction is reversely rotated as compared to when it is incident on the solid immersion lens SIL side. Becomes That is, the quarter-wave plate 1
After passing through 5, the light becomes vertical polarized light (a wave in which the vibration surface of the electric field is perpendicular to the paper surface in FIG. 3). Then, it is incident on the first beam splitter 13. At this time, since the recording / reproducing light DL is an S wave, it is reflected by the first beam splitter 13,
The light is condensed by the second condenser lens 26, is detected by the first detection sensor (information light detection sensor) 1B, and is output from the external output device O.
Send a reproduction signal to S.

On the other hand, the tracking light TL incident on the solid immersion lens SIL generates near-field light NP2 for tracking on the recording medium 20 side, and the groove portion 2 of the recording medium 20 is generated.
A tracking spot TS is generated above 0G. Then, in the flat portion 18U and the recording medium 20, interaction, reflected light, etc. occur. Details of the optical action and the like of the tracking light TL incident on the solid immersion lens SIL in the optical element peripheral portion 3 including the solid immersion lens SIL and the recording medium 20 will be described later. In this case, the light for recording and reproducing information on the recording medium 20 and the light for generating the tracking spot TS for performing tracking on the recording medium 20 are both near-field light NP1 and NP2. .

The tracking light TL reflected by the flat surface portion 18U and the recording medium 20 to be reflected light travels to the second beam splitter 21 almost in the reverse optical path.
Specifically, the condenser lens 17 passes through the solid immersion lens SIL.
And is incident on the half mirror 16. Then, the tracking light TL half-reflected from the semi-transparent surface 16A of the half mirror 16 passes through the shielding plate 28, and the total reflection mirror 25.
And is incident on the quarter-wave plate 22. Here, since the tracking light TL that is incident on the quarter-wave plate 22 is once reflected by the recording medium 20, the polarization direction is opposite to that when it is incident on the solid immersion lens SIL side. Become. That is, after passing through the quarter-wave plate 22, it becomes vertically polarized light (a wave in which the vibration plane of the electric field is perpendicular to the paper surface in FIG. 3). Then, it is incident on the second beam splitter 21. At this time, since the tracking light TL is an S wave, it is reflected by the second beam splitter 21, condensed by the third condenser lens 27, and tracking information is obtained by the second detection sensor (tracking information light detection sensor) 2B. The detected tracking information is sent to the tracking controller CONT.

Based on the tracking information sent to the tracking controller CONT, an instruction is sent to the near-field light generator driving device M to perform tracking. The outline of the procedure for recording information on the recording medium 20 and reproducing the recorded information has been described above. The tracking operation is always performed while the information is recorded and reproduced. When recording and / or erasing information, the wavelength and output of the recording / reproducing light DL used are changed.

Optical element peripheral portion 3 including the solid immersion lens SIL
For the above, an enlarged view is shown in FIG. Figure 8 (a)
8A is a cross-sectional view of the optical element peripheral portion 3, FIG. 8B is a bottom view of the solid immersion lens SIL, and FIG. 9A and 9B are views for explaining the positional relationship between the spot generated by the field light NP1 and the near-field light NP2 for tracking and the recording medium 20, and FIG.
(d) is a diagram illustrating the recording pits DP formed on the recording medium 20.

First, regarding the structure of the solid immersion lens SIL,
This will be described with reference to FIGS. 8 (a) and 8 (b). The optical element is
It is mainly composed of a solid immersion lens SIL. Solid immersion lens SI
L is composed of a high refractive index material such as lanthanum silica glass or lead silica glass as a substantially hemispherical body portion 18, and is formed in a substantially flat surface with a spherical portion 18S formed in a substantially hemispherical shape. And a flat surface portion (bottom surface portion) 18U. In addition, a thin film 19 for forming a substantially circular minute opening is formed near the center of the flat portion 18U of the solid immersion lens SIL, and a minute opening 19H is formed in the thin film 19. The minute opening 19H is formed so as to be smaller than the size of a light spot formed by condensing the recording / reproducing light DL near the flat portion 18U of the solid immersion lens SIL. As a result, the near-field light NP1 having a smaller spot than the light spot at the focus position can be exuded from the bottom surface side of the solid immersion lens SIL. That is, it is possible to obtain a small light spot that exceeds the diffraction limit of the original recording / reproducing light TL. A metal film of Al, Ni, Cr or the like can be used for the thin film 19, and the minute opening 19H is formed by a well-known fine processing technique such as photolithography. Here, the size of the thin film 19 may be a little larger than the spot of the recording / reproducing light DL, and the tracking light TL is focused on the portion of the flat surface portion 18U where the thin film 19 is not provided. , When totally reflected, solid immersion lens SIL
Near-field light NP2 is generated from the bottom side of the. Note that, if the tracking light TL is irradiated substantially vertically to the portion of the flat surface portion 18U where the thin film 19 is not provided, the tracking light TL is transmitted through the flat surface portion 18U. 18U is formed.

Next, the optical function of the optical element peripheral portion 3 will be described. The recording / reproducing light DL is converged by the first condenser lens 17, and enters the solid immersion lens SIL from the predetermined incident position to the inside of the solid immersion lens SIL. The recording / reproducing light that has entered the solid immersion lens SIL is condensed on the substantially central portion of the flat portion 18U of the solid immersion lens SIL. Since the solid immersion lens SIL is formed of a medium having a high refractive index, the light spot condensed in the medium is a minute spot as compared with the spot formed in the air. For example, depending on the refractive index of the high-refractive index medium forming the solid immersion lens SIL, the diameter of the light spot formed inside the solid immersion lens SIL is set to half or less of the wavelength of the recording / reproducing light DL in air. It can also be designed to be Therefore, the wavelength of the recording / reproducing light DL is 400 n.
If it is about m, the flat portion 18U inside the solid immersion lens SIL
The diameter of the light spot formed in the vicinity can be narrowed down to about 200 nm.

When the minute opening 19H is formed at the position of this light spot, a part of the near-field light oozes out as it is from the minute opening 19H. Since the minute aperture 19H is formed smaller than the light spot diameter, the spot diameter of the near-field light NP1 becomes smaller than the spot diameter of the recording / reproducing light DL formed inside the solid immersion lens SIL. Since the near-field light NP1 is non-propagating light, it exists only in the area (near field area) near the minute aperture 19H formed in the solid immersion lens SIL.

Near-field light N leached from the minute aperture 19H
P1 is irradiated onto the land portion 20L of the recording medium 20,
A recording / reproducing spot DS is generated on the land portion 20L, a recording pit DP is formed on the land portion 20L, and reflected light is generated on the land portion 20L.

On the other hand, the tracking light TL is made into convergent light by the first condenser lens 17, and enters the inside of the solid immersion lens SIL from a predetermined incident position of the spherical surface portion 18S of the solid immersion lens SIL. The tracking light TL incident on the solid immersion lens SIL is condensed on a portion of the flat portion 18U of the solid immersion lens SIL where the thin film 19 is not provided and is totally reflected, and the near-field light NP2 is directed to the recording medium 20 side. Generate. Since the material forming the solid immersion lens SIL is a high-refractive index medium, a spot generated by condensing the tracking light TL on the flat surface portion 18U is generated in the air like the recording / reproducing light DL. The tracking spot TS generated by the near-field light NP2 is also comparatively small. The near-field light NP2 is irradiated above the groove portion 20G of the recording medium 20 to generate the tracking spot TS above the groove portion 20G, but since it does not reach the groove portion 20G, it interacts with the groove portion 20G. Does not occur. Here, if
When the near-field light NP2 is applied to the land portion 20L of the recording medium 20, energy loss occurs, and as a result, the tracking light TL that is reflected by the flat surface portion 18U and the recording medium 20 and reaches the second detection sensor 2B. Will decrease in intensity.

FIG. 9C is a view of the recording medium 20 seen from above, and the position of the solid immersion lens SIL is indicated by a broken line for reference. The recording / reproducing spot DS by the near-field light NP1 is generated on the land portion 20L, and the tracking spot TS by the near-field light NP2 is generated above the groove portion 20G. Here, the tracking spot TS
Is located at a position deviated from the recording / reproducing spot DS in both the circumferential direction and the radial direction of the recording medium 20, and by doing so, the thin film 19 does not block the tracking light, With respect to the recording medium 20, the position where the recording / reproducing spot DS is generated and the position where the tracking spot TS is generated can be set as close to the radial direction as possible. Here, if the tracking spot T
Assuming that S is displaced from the recording / reproducing spot DS only in the radial direction of the recording medium, the recording / reproducing spot DS and the tracking spot TS in the radial direction are more than in the state shown in FIG. 9C. The distance can only be set far. Therefore, in the situation as shown in FIG. 9 (c), the width of the land portion 20L can be made relatively narrow, so that the recording density in the radial direction on the recording medium 20 is improved. The width of the land portion 20L can be reduced to the diameter of the minute recording / reproducing spot DS as long as the tracking accuracy permits.

FIG. 9D shows recording pits DP formed on the recording medium 20. The recording medium 20 rotates,
Since the optical element moves relatively to the recording medium 20 along the tracking pattern, the recording pit DP is formed along the tracking pattern. here,
Not only the width of the land portion 20L can be made relatively narrow, but also the near-field light NP generated in the minute aperture 19H is generated.
Since the minute recording / reproducing spot DS is obtained by 1, the recording pit DP can be made to be a relatively small pit, and as a result, the interval between the recording pits DP on the land portion 20L (circumferential direction). It becomes possible to narrow the pitch).

FIGS. 1 to 3 and 8 show an example of the embodiment according to the present invention. The light generating section 1, the tracking light adjusting section 2 and the optical element peripheral section 3 will be further described later. There are specific examples that do, and various embodiments of the present invention can be configured by combining various specific examples. Hereinafter, specific examples of the light generating section 1, the tracking light adjusting section 2, and the optical element peripheral section 3 will be described, and combinations of specific examples will be described later.

<2. Specific Example of Light Generation Unit 1> FIG.
In the above, the first specific example of the light generating section 1 is shown, but the light generating section 1 has the following second specific example.

<2.1. Second Specific Example> FIG. 4 is a diagram showing a second specific example of the light generating section 1. In this example, the second laser diode 21A, the third laser diode 22A, the second collimator lens 211, and the third collimator lens 212 are provided. The second and third laser diodes 21A and 22A are composed of semiconductor lasers or the like, and generate the recording / reproducing light DL and the tracking light TL for irradiating the solid immersion lens SIL, respectively. The recording / reproducing light DL from the second laser diode 21A is converted into parallel light having a predetermined luminous flux width by the second collimator lens 211, and the tracking light TL from the third laser diode 22A is similarly converted to the third collimator. It is converted into parallel light having a predetermined light flux width by the lens 212. Here, the wavelengths of the recording / reproducing light DL and the tracking light may be the same wavelength or different wavelengths. Further, the light generated from the second and third laser diodes 21A and 22A is arranged so as to be horizontally polarized (a wave in which the vibration surface of the electric field is in the plane of the paper in FIG. 4).

<3. Specific Example of Tracking Light Adjusting Unit 2> In FIG. 3 described above, the first specific example of the tracking light adjusting unit 2 is shown. However, the tracking light adjusting unit 2 has the following specific examples. . In the specific examples shown below, since there are similar parts to each other, such parts are designated by the same reference numerals.

<3.1. Second Specific Example> FIG. 5 is a diagram showing a second specific example of the tracking light adjusting section 2.
In this example, the shield plate 28 is removed from the first specific example of the tracking light adjusting unit 2 shown in FIG.
That is, here, the tracking light TL is emitted from the tracking light adjustment unit 2 without becoming a cylindrical light beam. The rest of the description is similar to that of the first specific example, and therefore the description is omitted here. Here, similarly to the first specific example, the total reflection mirror 25 is not limited to a fixed one, and a relative angle with respect to the tracking light TL is set by a mechanism similar to that of a movable parallel flat plate 50 described later. The relationship may be changed and the optical path of the tracking light TL after being reflected by the total reflection mirror 25 may be shifted.

<3.2. Third Specific Example> FIG. 6 is a diagram showing a third specific example of the tracking light adjusting section 2.
In FIG. 6, in order to clarify the rotation direction of the movable parallel flat plate 50 and the deviation direction of the optical path, which will be described later, the rotation directions 50A and 50B of the movable parallel flat plate 50 and the deviation directions 50C and 50D of the optical path are shown. Attached. In this example, a quarter
The wave plate 22, the movable parallel plate 50, the rotary shaft rod 51, the total reflection mirror 25, and the shield plate 28 are included. Tracking light TL incident on the tracking light adjusting unit 2
First passes through the quarter wave plate 22. At this time, the tracking light TL including only the horizontally polarized component becomes circularly polarized light. The circularly polarized tracking light TL is incident on the movable parallel plate 50. The movable parallel flat plate 50 is made of a glass plate or the like as a material, and has a rotating shaft 5 on the side surface.
50A shown in the figure with the rotary shaft rod 51 as an axis according to an instruction from the rotary motor control unit MR which is connected to a rotary motor (not shown) by 1 and mainly includes a CPU and the like.
And a mechanism for rotating in the direction of 50B. Therefore, by changing the angle formed by the tracking light TL incident on the movable parallel plate 50 and the movable parallel plate 50 variously, the refraction of the tracking light TL in the movable parallel plate 50 is utilized to make the movable type parallel. The optical path of the tracking light TL after passing through the parallel plate 50 can be variously shifted in the directions of 50C and 50D. As a concrete example, the movable parallel plate 50 is moved to the state shown in FIG.
FIG. 6 (b) shows the state after the rotation in the 0B direction. 6 (b), in order to clarify the rotation of the movable parallel plate 50, the position (state of FIG. 6 (a)) 50a of the movable parallel plate 50 before rotation is shown. The optical path of the tracking light TL before the rotation of the movable parallel plate 50 is also shown by a broken line in order to clarify the shift direction of the. Figure 6
As shown in FIGS. 6A and 6B, by rotating the movable parallel plate 50 in the direction of 50B, the tracking light TL incident on the movable parallel plate 50 and the movable parallel plate 50 are separated. The optical path of the tracking light TL after changing the angle formed and passing through the movable parallel plate 50 is denoted by 50D in the figure.
Can be shifted in the direction of. The tracking light TL that has passed through the movable parallel plate 50 is reflected by the total reflection mirror 25, and the shielding plate 28 shields only the inside of the light flux of the tracking light TL, and only the outer edge of the light flux is the tracking light adjustment unit. Eject from 2. Further, here, the shielding plate 28 is provided after the tracking light TL is reflected by the total reflection mirror 25, but it may be provided on the light source side of the movable parallel plate 50.

<3.3. Fourth Specific Example> FIG. 7 is a diagram showing a fourth specific example of the tracking light adjusting section 2.
This example is obtained by removing the shield plate 28 from the third specific example of the tracking light adjusting section 2 shown in FIG. Therefore, the description is omitted to avoid duplication of description.

<4. Specific Example of Optical Element Peripheral Part 3> Although the first specific example of the optical element peripheral part 3 is shown in FIG. 8 described above, the optical element peripheral part 3 has the following specific examples.

<4.1. Second Specific Example> FIGS. 9 and 10 are views showing a second specific example of the optical element peripheral portion 3. FIG. Here, the solid immersion lens SI of the tracking light TL is used.
By switching the incident area linked with the incident angle with respect to L in two steps, two recording pit rows DPA and DPB are formed on the land portion 20L. FIG. 9 shows a state before switching the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL, and FIG.
Shows the state after switching the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL. Therefore, the difference between FIG. 9 and FIG. 10 is that the incident area interlocked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL is slightly changed, and the incident angle of the tracking light TL with respect to the solid immersion lens SIL is changed. Recording / playback spot D associated with changes in the incident area linked to
There is no difference in the structure of the solid immersion lens SIL and the like except that the positions of S and the tracking spot TS change. Therefore, similar parts are designated by the same reference numerals, and description thereof will be omitted here.

Further, in FIG. 9, as in FIG.
10 (a) is a sectional view of the optical element peripheral portion 3, FIGS. 9 (b) and 10 (b) are bottom views of the solid immersion lens SIL, and FIGS. (c) is a solid immersion lens S
9 (d) and 10 (d) are views for explaining the positional relationship between spots generated by the near-field light NP1 and NP2 for recording / reproducing and tracking emitted from the IL and the recording medium 20, and FIGS. 5 is a diagram illustrating recording pit rows DPA and DPB formed on the recording medium 20. FIG.

FIG. 9 is almost the same as FIG.
8 is different from FIG. 8 in that the radial width of the land portion 20L of the recording medium 20 is wide, the row of the recording pits DP is the recording pit row DPA, and the tracking light TL is switched. The previous tracking light TL and the recording medium 20 are the tracking light TLA and the recording medium 20A, respectively, and the tracking light TLB and the recording medium 20 after the tracking light TL is switched.
B, the tracking spot TSB and the recording pit row DPB formed on the recording medium 20B are only points indicated by broken lines. The state after switching the tracking light TL is shown in FIG. 10 and will be described later.

In FIG. 9, since the width of the land portion 20L in the recording medium 20A in the radial direction is wide, the width shown in FIG.
As shown in, the recording pit row DPA is not formed substantially at the center of the land portion 20L in the radial direction, but is formed at a slightly displaced position. The other parts in FIG. 9 are similar to those in FIG.

Next, FIG. 10 showing the state after switching the tracking light TL from FIG. 9 will be described. Figure 1
Contrary to FIG. 9, the tracking light TLB after switching the tracking light TL is indicated by a thick line at 0, and the recording medium 20B, the tracking spot TSB, and the recording pit row DPB are indicated by a solid line at 0. On the other hand, the tracking light T before switching the tracking light TL
LA, recording medium 20A, tracking spot TSA
The recording pit row DPA is indicated by a broken line.

In FIG. 10, the position of the spot of the near-field light NP2 on the recording medium 20 in FIG. 9 is changed from the width of the land portion 20L to the recording / reproducing spot DS in the radial direction.
The distance is slightly shorter than the distance obtained by subtracting the diameter of. Note that, here, even after the tracking light TL is switched, the position where the tracking light TL is focused on the plane portion 18U is the near-field light NP2 due to the thin film 19.
It is a position where the generation of That is, the tracking light TL is condensed at a position where the thin film 19 is not provided on the flat surface portion 18U. Further, the movement of the spot of the near-field light NP2 with respect to the recording medium 20, that is, the switching, is performed by the solid immersion lens S of the tracking light TL.
This is performed by changing the incident area linked to the incident angle with respect to IL. This change of the incident area of the tracking light TL in association with the incident angle of the solid immersion lens SIL is performed by shifting the optical path of the tracking light TL in the tracking light adjusting unit 2 and condensing it from the tracking light adjusting unit 2. This is achieved by relatively changing the incident angle of the tracking light TL to the lens 17 and the incident angle of the recording / reproducing light DL to the condenser lens 17.
Thus, the solid immersion lens SIL of the tracking light TL is
By switching the incident area linked to the incident angle with respect to, the tracking spot TSB and the recording / reproducing spot DS are generated at the positions shown in FIG. 10C, and as a result, FIG. As shown, the recording pit row DPB is formed at a position different from the recording pit row DPA shown in FIG. 9D.

That is, here, the near-field light is changed by relatively changing the incident angles of the recording / reproducing light DL and the tracking light TL which are incident on the first condenser lens 17 by the tracking light adjusting section 2. The relative positional relationship between the minute aperture generated by NP1 and the position generated by the near-field light NP2 is changed.

Further, here, the distance between the tracking spots before and after the switching of the incident area linked to the incident angle of the tracking light TL with respect to the solid immersion lens SIL, that is, the distance between the tracking spot TSA and the tracking spot TSB is Too close,
In order to prevent the recording pit rows DPA and DPB from overlapping, switching of the incident area is set in association with the incident angle of the tracking light TL with respect to the solid immersion lens SIL. 9 and 10, the recording medium 20 is shown as if it is moving with respect to the solid immersion lens SIL. However, this is for convenience of illustration and FIG. 9 and FIG.
The recording medium 20 is actually rotated, and the solid immersion lens SIL moves in the radial direction of the recording medium 20 with respect to the recording medium 20.

Here, as shown in FIGS. 9 and 10, by switching the two tracking spots TSA and TSB generated by switching the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL. Two recording pit rows DPA and DPB can be formed on one land portion 20L of the recording medium 20. Therefore, the recording density in the radial direction of the recording medium 20 can be improved.

<4.2. Third Specific Example> FIGS. 11 to 1
FIG. 4 is a diagram showing a third specific example of the optical element peripheral portion 3. Here, by a method similar to that of the second specific example of the optical element peripheral portion 3 shown in FIGS. 9 and 10, the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL is switched to four stages. As a result, four recording pit rows DP1 to DP4 are formed in the land portion 20L. FIG. 11 shows the solid immersion lens S of the tracking light TL.
FIG. 12 shows a state before switching the incident area linked to the incident angle with respect to IL, and FIGS. 12 to 14 show steps after switching the incident area linked with the incident angle with respect to the solid immersion lens SIL of the tracking light TL. It shows the state. Therefore, in FIGS. 11 to 14, only the incident area of the tracking light TL linked with the incident angle of the solid immersion lens SIL is slightly changed. There is no change in the structure except for the positions of the spot DS, the tracking spot TS and the recording pit DP. Therefore, similar parts are designated by the same reference numerals, and description thereof will be omitted here.

First, FIG. 11 will be described. Similar to FIG. 9, FIG. 11A is a sectional view of the optical element peripheral portion 3, and FIG. 11B is a bottom view of the solid immersion lens SIL.
FIG. 11C is a diagram for explaining the positional relationship between the spots generated by the near-field light NP1 and NP2 for recording and reproduction emitted from the solid immersion lens SIL and the recording medium 20, and FIG. FIG. 3D is a diagram illustrating a recording pit row DP1 formed on the recording medium 20.

FIG. 11 is almost the same as FIG. 9, and the difference between FIG. 11 and FIG. 9 is that the width of the land portion 20L in the recording medium 20 in the radial direction is further widened. , The recording pit row DPA is shown in FIG.
Then, the recording pit row DP1 and the tracking spots TS2, TS3, TS4 and the recording pit row DP2, D4 after switching the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL.
P3 and DP4 are points indicated by broken lines. The state after the stepwise switching of the incident area interlocked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL is shown in FIGS. 12 to 14 and will be described later.

In FIG. 11, since the width of the land portion 20L in the recording medium 20 in the radial direction is wide,
As shown in (d), the recording pit row DP1 has the land portion 20.
It is not formed substantially at the center of L in the radial direction, but is formed at the end. The other parts in FIG. 11 are the same as those in FIG. 9, so description thereof will be omitted.

Next, FIG. 12 is a diagram for explaining the state after switching the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL from the state shown in FIG. In FIG. 12, after switching the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL, the recording / reproducing and tracking near-field lights NP1 and NP2 emitted from the solid immersion lens SIL are generated. 12 (a) for explaining the positional relationship between the spots and the recording medium 20 and FIG. 12 (b) for explaining formation of the recording pit row DP2 formed on the recording medium 20.

In FIG. 12, a tracking spot TS2 generated after switching the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL.
And the recording pit row DP2 are shown by solid lines, while the solid immersion lens SIL of the other tracking light TL is shown.
Tracking spots TS1 and TS generated corresponding to the switching of the incident area linked to the incident angle with respect to
3, TS4 and recording pit rows DP1, DP3, DP4
Is indicated by a broken line.

Further, in FIG. 12, the position of the tracking spot TS1 generated on the recording medium 20 in FIG.
It is moved a little longer than the diameter of, and is also moved slightly in the circumferential direction. It should be noted that here, even after the incident area linked with the incident angle of the tracking light TL with respect to the solid immersion lens SIL is switched, the position where the tracking light TL is focused on the flat portion 18U is the near-field light by the thin film 19. The position is such that the production of NP2 is not inhibited. That is, the tracking light TL is condensed at a position where the thin film 19 is not provided on the flat surface portion 18U. In addition, the solid immersion lens SI of the tracking light TL
By switching the incident area linked to the incident angle with respect to L, the tracking spot TS2 and the recording / reproducing spot DS are generated at the positions shown in FIG. 12A, and as a result, FIG. As shown in
A recording pit row DP2 is formed at a position different from the recording pit row DP1 shown in FIG. 11 (d).

Further, from FIG. 12, the tracking light TL
FIG. 13 and FIG. 14 show the state after switching the incident area linked with the incident angle with respect to the solid immersion lens SIL. Change from FIG. 12 to FIG. 13 and FIG. 13 to FIG.
The change to 4 is similar to the above-described change from FIG. 11 to FIG. Since the tracking spots TS3 and TS4 and the recording / reproducing spot DS are formed at the positions shown in FIG. 14A, as a result, as shown in FIG.
As shown in (b) and FIG. 14 (b), at a position further different from the recording pit row DP2 shown in FIG. 12 (b),
Recording pit rows DP3 and DP4 are formed.

Thus, as shown in FIGS. 11 to 14, four-step tracking spots TS1 to TS are generated by switching the incident position of the tracking light TL linked with the incident angle of the solid immersion lens SIL.
By switching 4 the recording / playback spot DS
Of the recording medium 2 without jumping over the groove portion 20G.
Four recording pit rows DP1 to DP4 can be formed on one land portion 20L at 0. Therefore, the recording density in the radial direction of the recording medium 20 can be further improved.

<4.3. Fourth Specific Example> FIG. 15 is a diagram showing a fourth specific example of the optical element peripheral portion 3. In FIG. 8, the near-field light NP2 for tracking is generated in a portion of the plane portion 18U where the thin film 19 is not present. The near-field light NP2 is also generated.
As in FIG. 8, FIG. 15 (a) is a sectional view of the optical element peripheral portion 3, FIG. 15 (b) is a bottom view of the solid immersion lens SIL, and FIG. 15 (c) is Near-field light N for recording / reproducing and tracking emitted from the solid immersion lens SIL
15D is a diagram for explaining the positional relationship between the spots generated by P1 and NP2 and the recording medium 20, and FIG.
It is a figure explaining the recording pit DP formed in 0.

Since many parts in FIG. 15 are similar to those in FIG. 8, the same symbols are used and the description thereof is omitted. In addition, FIG.
The difference between FIG. 8 and FIG. 8 is the size of the thin film 19 and the recording medium 2
0 width of the groove portion 20G in the radial direction, the optical path of the tracking light TL, and the near-field light NP for tracking
2 is generated and the position of the tracking spot TS generated by the near-field light NP2 is different. Hereinafter, parts different from those in FIG. 8 will be described together with the features in FIG.

First, the structure of the optical element peripheral portion 3 in the fourth specific example will be described. 15 (a) and FIG.
As shown in (b), a thin film 19 for forming a minute aperture is formed almost entirely on the flat surface portion 18U of the solid immersion lens SIL,
A minute opening 19H is formed near the center of the thin film 19.
Here, the wavelengths of the recording / reproducing light DL and the tracking light TL are different, but as in the case of FIG. 8, the thin film 19 has the wavelength of the recording / reproducing light DL and the tracking light TL.
Do not allow light of the same wavelength to pass through. Further, here, the width of the groove portion 20G of the recording medium 20 in the radial direction is narrowed, and the reason for this will be described later.

Next, optical functions such as information recording / reproducing and tracking operations in the fourth specific example of the optical element peripheral portion 3 shown in FIG. 15 will be described. As shown in FIG. 15 (a), the near-field light NP leached from the minute aperture 19H
1 is irradiated onto the land portion 20L of the recording medium 20,
A recording / reproducing spot DS is generated to form a recording pit DP on the land portion 20L, while reflected light is also generated. Further, the tracking light TL incident on the solid immersion lens SIL also receives the solid immersion lens SI as in the recording / reproducing light DL.
A near-field light NP2 is generated by generating a spot in the minute aperture 19H in the flat portion 18U of L,
A tracking spot TS is generated.

FIG. 15C is a view of the recording medium 20 seen from above, and the position of the solid immersion lens SIL is indicated by a broken line for reference. The recording / reproducing spot DS by the near-field light NP1 is generated on the land portion 20L, and the tracking spot TS by the near-field light NP2 is also generated on the land portion 20L. Here, the positions where the recording / reproducing spot DS and the tracking spot TS occur are the same. Therefore, on the recording medium 20, the position for recording / reproducing information and the position for tracking are the same position, so that tracking can be performed with high accuracy. Note that, here, the near-field light NP2 generated in the flat surface portion 18U has a narrow interval between the flat surface portion 18U and the land portion 20L, and thus the land portion 20 is similar to the near-field light NP1.
Since it is possible to reach L, the near-field light NP2 is
The tracking spot TS is generated on the land portion 20L.

FIG. 15D shows recording pits DP formed on the recording medium 20. Here, not only can tracking be performed with high accuracy, but a minute recording / reproducing spot DS can be obtained by the near-field light NP1 generated in the minute aperture 19H, so the recording pit DP should also be a relatively minute pit. Is possible.
Further, since recording / reproducing and tracking of information are performed at the same position on the land portion 20L, it is possible to narrow the radial width of the groove portion 20G in the recording medium 20. Furthermore, since tracking is also performed by the near-field light NP2 generated in the minute aperture 19H, the tracking spot TS becomes a minute spot. Therefore, it is possible to narrow the interval (circumferential pitch) between the recording pits DP on the land portion 20L, and the width of the land portion 20L is smaller than that of the minute recording / reproducing spot DS and tracking spot TS. It is possible to make it as narrow as the diameter. Further, since tracking is not performed in the groove portion 20G, the width of the groove portion 20G in the radial direction is set so that the width of the groove portion 20G is too narrow when recording and reading information, and the groove portions 20G are adjacent to each other. The recording density can be improved because it can be narrowed to the extent that there is no crosstalk in which the optical effects on the arranged land portions 20L affect each other.

Although the thin film 19 is provided on the entire planar portion 18U here, the invention is not limited to this.
The size of the thin film 19 may be larger than the spots of the recording / reproducing light DL and the tracking light TL generated by being condensed on the minute opening 19H.

<4.4. Fifth Concrete Example> FIG. 16 is a diagram showing a fifth concrete example of the optical element peripheral portion 3. Figure 15
In the above, the near-field light NP1 and the near-field light NP2 are both generated in the same minute opening 19H, but here, the near-field light NP1 and the near-field light NP2 are generated in separate minute openings. Then, as in FIG. 15, FIG. 16A is a cross-sectional view of the optical element peripheral portion 3,
FIG. 16B is a bottom view of the solid immersion lens SIL.
FIG. 6C is a diagram for explaining the positional relationship between the recording medium 20 and the spots generated by the recording / reproducing and tracking near-field light NP1 and NP2 emitted from the solid immersion lens SIL, and FIG. FIG. 3D is a diagram illustrating the recording pit DP formed on the recording medium 20.

Since many parts in FIG. 16 are similar to those in FIG. 15, parts similar to those in FIG. 15 are designated by the same reference numerals, and their description will be omitted. Further, the difference between FIG. 16 and FIG. 15 is that the number of minute apertures and the optical path of the tracking light TL are
This is that the place where the near-field light NP2 for tracking is generated and the position of the tracking spot TS generated by the near-field light NP2 for tracking are different. Hereinafter, parts different from FIG. 15 will be described together with the features in FIG. 16.

First, the structure of the optical element peripheral portion 3 in the fifth specific example will be described. 16 (a) and 16
As shown in (b), a small opening 19Ha for recording / reproducing is formed near the center of the thin film 19, and a small opening 19Hb for tracking is formed at a position slightly apart from the small opening 19Ha for recording / reproducing. There is. The distance between these two minute openings 19Ha and 19Hb is
The spots of the recording / reproducing light TL and the tracking light TL focused on Ha and 19Hb can be brought close to each other so that they do not overlap. Here, the minute openings 19Ha, 19 are formed not only in the radial direction of the recording medium 20 but also in the circumferential direction.
By shifting the position of Hb, the positions of the minute openings 19Ha and 19Hb can be brought closer to each other in the radial direction as much as possible without overlapping the spots of the recording / reproducing light DL and the tracking light TL on the flat surface portion 18U. The reason why the positions of the minute openings 19Ha and 19Hb should be brought closer to each other in the radial direction will be described later. The recording / reproducing optical DL
And when the wavelength of the tracking light TL is different,
Even if the spots of the recording / reproducing light DL and the tracking light TL do not overlap with each other, they do not affect each other. Therefore, the minute openings 19Ha, 19H are located at positions where the spots of the recording / reproducing light DL and the tracking light TL overlap.
b may be arranged.

Next, optical functions such as information recording / reproducing and tracking operations in the fifth specific example of the optical element peripheral portion 3 shown in FIG. 16 will be described. As shown in FIG. 16A, the near-field light N leached from the minute aperture 19Ha
P1 is irradiated onto the land portion 20L of the recording medium 20 to generate a recording / reproducing spot DS, and the land portion 20L
While forming the recording pit DP on the upper side, reflected light is also generated. Further, the tracking light TL that has entered the solid immersion lens SIL is condensed on the minute aperture 19Hb to generate the near-field light NP2 and generate the tracking spot TS. Here, in order to focus the recording / reproducing light DL and the tracking light TL at different positions, the tracking light adjusting unit is used in the same manner as described in the first specific example of the optical element peripheral portion 3. In 2, the optical paths of the recording / reproducing light DL and the tracking light TL incident on the solid immersion lens SIL are adjusted so as to be deviated.

FIG. 16C is a view of the recording medium 20 seen from above, and the position of the solid immersion lens SIL is indicated by a broken line for reference. The recording / reproducing spot DS by the near-field light NP1 is generated on the land portion 20L, and the tracking spot TS by the near-field light NP2 is generated immediately above the groove portion 20G. Here, as in the case shown in FIG. 8, since the plane portion 18U and the groove portion 20G are separated from each other, the near-field light NP2 does not reach the groove portion 20G. Here, similarly to the case shown in FIG. 8, by shifting the positions of the minute openings 19Ha and 19Hb not only in the radial direction of the recording medium 20 but also in the circumferential direction, the recording / reproducing light DL and the tracking light DL on the flat surface portion 18U. Micro aperture 19H without overlapping the spots of light TL
Since the positions of a and 19Hb can be brought closer to each other in the radial direction, tracking can be performed with high accuracy.

FIG. 16D shows the recording pits DP formed on the recording medium 20. Here, not only can accurate tracking be performed, but the near-field light NP1 generated in the minute aperture 19Ha
Since the minute recording / reproducing spot DS is obtained, the recording pit DP can also be a relatively minute pit. In addition, the minute opening 19Hb is formed in the groove portion 20G.
Since a minute tracking spot TS is obtained by the near-field light NP2 generated in the recording medium 20
It is possible to narrow the width of the groove portion 20G in the radial direction. Furthermore, the minute openings 19Ha, 19Hb
By moving the position of the land portion 20L in the radial direction as much as possible, the width of the land portion 20L in the radial direction is set to the tracking spot TS.
It can be as narrow as the diameter of. Therefore, here, it is possible to narrow the interval (circumferential pitch) between the recording pits DP on the land portion 20L, and set the widths of the groove portion 20G and the land portion 20L to the minute tracking spots TS and, respectively. Since the recording / reproducing spot DS can be made as narrow as the diameter thereof, the recording density can be improved.

Although the thin film 19 is provided on the entire planar portion 18U here, the invention is not limited to this.
The thin film 19 may be as small as a region where the recording / reproducing light DL and the tracking light TL generate spots on the flat surface portion 18U.

<4.5. Sixth Concrete Example> FIG. 17 is a diagram showing a sixth concrete example of the optical element peripheral portion 3. FIG.
In the above, the near-field light NP1 and the near-field light NP2 are generated in the separate minute openings 19Ha and 19Hb, but here, the near-field light NP1 and the near-field light NP2 are generated.
Are generated at both ends of the same slit-shaped opening 19S. Then, as in FIG. 16, FIG. 17 (a) is a sectional view of the optical element peripheral portion 3, FIG. 17 (b) is a bottom view of the solid immersion lens SIL, and FIG. 17 (c) is Solid immersion lens SI
A recording medium 2 and a spot generated by the near-field light NP1 and NP2 for recording and reproduction emitted from L and for tracking.
FIG. 17 is a diagram for explaining the positional relationship with 0, and FIG. 17D is a diagram for explaining the recording pits DP formed on the recording medium 20.

Since many parts in FIG. 17 are the same as those in FIG. 16, the same parts as those in FIG. 16 are designated by the same reference numerals and the description thereof will be omitted. Further, the difference between FIG. 17 and FIG. 16 is that the two minute apertures 19Ha and 19Hb for generating the near-field light NP1 and NP2 are one slit-shaped aperture 1.
The point is 9S. Hereinafter, the parts different from FIG. 16 will be described together with the features in FIG.

First, the structure of the sixth example of the optical element peripheral portion 3 will be described. 17 (a) and FIG.
As shown in (b), the slit-shaped opening 19S is formed so that one end is arranged near the center of the thin film 19, and the other end of the slit-shaped opening 19S is formed with respect to one end. The slit-shaped openings are formed at positions displaced not only in the radial direction of the recording medium 20 but also in the circumferential direction. By doing so, both ends of the slit-shaped opening 19S can be brought close to each other in the radial direction of the recording medium 20 without overlapping the spots of the recording / reproducing light TL and the tracking light TL. Here, the width of the slit of the slit-shaped opening 19S is as shown in FIG.
Similar to the minute opening 19H, the recording / reproducing light DL and the tracking light TL are formed so as to be smaller than the size of the light spot formed by being condensed in the vicinity of the flat portion 18U. The reason why both ends of the slit-shaped opening 19S are brought closer to each other in the radial direction of the recording medium 20 will be described later. Incidentally, here, the recording / reproducing light TL is used.
If the wavelengths of the tracking light TL are the same, and the spots of the recording / reproducing light TL and the tracking light TL overlap with each other, they affect each other, and in such a case, in the longitudinal direction of the slit-shaped opening 19S. It is necessary to lengthen the length of the so that the spots of the recording / reproducing light TL and the tracking light TL do not overlap. The width of the slit is preferably 200 nm or less, and the length of the slit in the major axis direction is preferably 500 nm or more.

Next, optical functions such as information recording / reproducing and tracking operations in the sixth specific example of the optical element peripheral portion 3 shown in FIG. 17 will be described. As shown in FIG. 17A, the recording / reproducing light DL is condensed at one end of the slit-shaped opening 19S, and the near-field light NP1 becomes the recording medium 20.
Side, and the tracking light TL is condensed at the other end of the slit-shaped opening 19S, and the near-field light NP2 oozes out to the recording medium 20 side. Here, the long axis direction of the circularly polarized light of the recording / reproducing light DL and the tracking light TL and the longitudinal direction of the slit-shaped opening 19S are parallel to each other, so that both ends of the slit-shaped opening 19S are brought close to each other by the edge effect. Field lights NP1 and NP2 are generated. Therefore, in the sixth specific example of the optical element peripheral portion 3, the longitudinal direction of the slit and the long axis direction of the circularly polarized light are parallel to each other.
It is assumed that the slit-shaped opening 19S and the other part of the information recording / reproducing apparatus A are arranged.

The near-field light NP1 leached from one end of the slit-shaped opening 19S is the land 2 of the recording medium 20.
The recording / reproducing spot DS is generated by being irradiated onto 0L to form the recording pit DP on the land portion 20L, while reflected light is also generated. In addition, the slit-shaped opening 19S
The near-field light NP2 that oozes out from the other end portion of the above-mentioned optical disc generates a tracking spot TS above the groove portion 20G.

FIG. 17C is a view of the recording medium 20 seen from above, and the position of the solid immersion lens SIL is indicated by a broken line for reference. The recording / reproducing spot DS by the near-field light NP1 is generated on the land portion 20L, and the tracking spot TS by the near-field light NP2 is generated above the groove portion 20G. Here, since the distance between the recording / reproducing spot DS and the tracking spot TS can be reduced in the radial direction of the recording medium 20, tracking can be performed with high accuracy. Note that, as in the case shown in FIG. 16, since the planar portion 18U and the groove portion 20G are separated from each other, the near-field light NP2 is not included in the groove portion 20.
Does not reach G.

FIG. 17D shows recording pits DP formed on the recording medium 20. Here, not only can tracking be performed with high accuracy, but a minute recording / reproducing spot DS can be obtained by the near-field light NP1 generated in the slit-shaped opening 19S, so the recording pit DP is also a relatively minute pit. It is possible. Further, since the minute tracking spot TS is obtained by the near-field light NP2 generated in the slit-shaped opening 19S with respect to the groove portion 20G, the radial width of the groove portion 20G in the recording medium 20 can be narrowed. It is possible. Furthermore, the slit-shaped opening 19S
Since the distance between the recording / reproducing spot DS and the tracking spot TS can be shortened in the radial direction by bringing the positions of both ends of the recording medium 20 closer to the radial direction with respect to the recording medium 20, the land portion 20L in the radial direction. Can be narrowed to about the diameter of the tracking spot TS. Therefore, it is possible to narrow the interval (pitch in the circumferential direction) between the recording pits DP on the land portion 20L, and to reduce the groove portion 20G and the land portion 2.
The width of 0L is a small tracking spot T
Since the diameter of S and the recording / reproducing spot DS can be reduced to about the diameter, the recording density can be improved.

Although the thin film 19 is provided on the entire planar portion 18U here, the invention is not limited to this.
The thin film 19 may be as small as an area where the recording / reproducing light DL and the tracking light TL generate spots on the flat surface portion 18U, and may be small as long as the slit-shaped opening 19S can be formed.

<4.6. Seventh Concrete Example> FIG. 18 is a diagram showing a seventh concrete example of the optical element peripheral portion 3. Here, a tracking light transmission film 190 for forming a minute opening 19H provided in the flat surface portion 18U of the solid immersion lens SIL.
Is made of a material that does not transmit the recording / reproducing light DL but only the tracking light TL. And
Similar to the specific example shown in FIG. 8 and the like, recording and reproduction of information by the near-field light NP1 and tracking by the near-field light NP2 are performed on the recording medium 20.

First, FIG. 18 will be described. Similar to FIG. 8, FIG. 18A is a sectional view of the optical element peripheral portion 3, and FIG. 18B is a bottom view of the solid immersion lens SIL.
FIG. 18C is a diagram for explaining the positional relationship between the spots generated by the near-field light NP1 and NP2 for recording and reproduction emitted from the solid immersion lens SIL and the recording medium 20, and FIG. FIG. 3D is a diagram illustrating the recording pit DP formed on the recording medium 20.

Since many parts in FIG. 18 are similar to those in FIG. 8, only different parts will be described here. The same parts as those in FIG. 8 are designated by the same reference numerals and the description thereof will be omitted. The difference between FIG. 18 and FIG. 8 is that the tracking light transmission film 190 formed on the flat portion 18U of the solid immersion lens SIL and the optical path of the tracking light TL are different. Further, due to the above differences, some differences also occur in other parts. Hereinafter, parts different from those in FIG. 8 will be described together with the features in FIG.

First, the structure of the optical element peripheral portion 3 in the seventh specific example will be described. 18 (a) and 18
As shown in (b), the planar light-transmitting film 190 for forming a minute aperture is formed almost entirely on the plane portion 18U of the solid immersion lens SIL, and the minute aperture is formed in the vicinity of the center of the tracking light-transmitting film 190. 19H is formed. here,
The wavelengths of the recording / reproducing light DL and the tracking light TL are different, and the tracking light transmitting film 190 is formed by the recording / reproducing light D.
It has a characteristic of not transmitting the light of the wavelength of L but the light of the wavelength of the tracking light TL, and plays the role of a filter which selectively transmits the light of the wavelength of the specific range. As the thin film 19 having such characteristics, there is a dichroic film or the like.

Next, optical functions such as information recording / reproducing and tracking operations in the seventh specific example of the optical element peripheral portion 3 shown in FIG. 18 will be described. As shown in FIG. 18A, the near-field light NP leached from the minute aperture 19H
1 is irradiated onto the land portion 20L of the recording medium 20,
A recording / reproducing spot DS is generated to form a recording pit DP on the land portion 20L, while reflected light is also generated. Further, when the tracking light TL that has entered the solid immersion lens SIL is condensed in a region having the minute aperture 19H in the flat surface portion 18U of the solid immersion lens SIL and totally reflected,
Similar to the case of FIG. 8, the near-field light NP2 is generated and the tracking spot TS is generated.

FIG. 18C is a view of the recording medium 20 seen from above, and the position of the solid immersion lens SIL is shown by a broken line for reference. The recording / reproducing spot DS by the near-field light NP1 is generated on the land portion 20L, and the tracking spot TS by the near-field light NP2 is also generated on the land portion 20L. Here, the positions where the tracking spot TS and the recording / reproducing spot DS occur are the same. Therefore, on the recording medium 20, the position for recording / reproducing information and the position for tracking are the same position, so that tracking can be performed with high accuracy. In addition, here, as in the case of FIG.
The near-field light NP2 generated in 8U is the land portion 20.
Since it is possible to reach L, the near-field light NP2 is
The tracking spot TS is generated on the land portion 20L.

FIG. 18D shows the recording pits DP formed on the recording medium 20. Here, not only can tracking be performed with high accuracy, but a minute recording / reproducing spot DS can be obtained by the near-field light NP1 generated in the minute aperture 19H, so the recording pit DP should also be a relatively minute pit. Is possible.
Further, since recording / reproducing and tracking of information are performed at the same position on the land portion 20L, it is possible to narrow the radial width of the groove portion 20G in the recording medium 20. Furthermore, since the near field light NP2 is also used for tracking, the tracking spot TS becomes relatively small.
Therefore, the recording pit DP on the land portion 20L
Since it is possible to narrow the interval (pitch in the circumferential direction) between them and to narrow the width of the groove portion 20G and the land portion 20L, it is possible to improve the recording density.

FIG. 19 shows a light transmitting film 190 for tracking.
6 is a conceptual diagram showing the transmission characteristics of the wavelength (λ1 (DL)) of the recording / reproducing light DL and the wavelength (λ2 (TL)) of the tracking light TL with respect to FIG.

FIG. 19A shows the case where the wavelength of the tracking light TL is longer than the wavelength of the recording / reproducing light DL, and the transmittance of the tracking light TL is α. At this time, since the wavelength of the recording / reproducing light DL can be set to be relatively short, the throughput of the near-field light NP1 generated in the minute aperture 19H can be improved.

FIG. 19B shows the tracking light T
This is a case where the wavelength of L is shorter than the wavelength of the recording / reproducing light DL, and the transmittance of the tracking light TL is β.
At this time, since the wavelength of the tracking light TL can be set to be relatively short, the tracking spot TS generated on the land portion 20L of the recording medium 20 should be made smaller than that shown in FIG. You can Therefore, by reducing the tracking spot TS, the radial width of the land portion 20L can be narrowed, and thus the recording density can be further improved.

<5. Combination of Specific Examples> Above, the first and second specific examples of the light generating section 1, the first to fourth specific examples of the tracking light adjusting section 2, and the optical element peripheral section 3 are described.
The first to the seventh concrete examples of No. have been described. Then, any one of the first or second specific examples of the light generating section 1, any one of the first to fourth specific examples of the tracking light adjusting section 2, and the optical element peripheral section. Various embodiments of the present invention can be configured by combining with any one of the first to seventh concrete examples of No. 3. However, the combination of the second or fourth specific example of the tracking light adjusting section 2 and any one of the first to third and seventh specific examples of the optical element peripheral section 3 is for the reason described later. Excluded.

The reason is as follows. In the second or fourth specific example of the tracking light adjusting unit 2, since the shielding plate 28 is not provided, the central portion of the light flux of the tracking light TL is not shielded, and the tracking light TL incident on the solid immersion lens SIL is Since the flat portion 18U does not totally reflect, the flat portion 18U of the solid immersion lens SIL uses the near-field light NP2 for tracking generated by the total reflection of the tracking light TL. ~ The second or fourth specific example of the tracking light adjusting unit 2 cannot be applied to the third and seventh specific examples.

As described above, not only the near-field light NP1 is used for recording / reproducing information on / from the recording medium 20, but also the near-field light N for detecting a tracking pattern.
By using P2 to bring the positions of the near-field light NP1 and the near-field light NP2 closer to each other in the optical element, it is possible to record or reproduce information with high resolution or high density, and perform accurate tracking. Is possible. Further, depending on the position of the tracking spot TS generated by the near-field light NP2, the radial width of the land portion 20L or the groove portion 20G, or both the land portion 20L and the groove portion 20G in the recording medium 20 can be narrowed. Therefore, it is possible to improve the recording density. Further, when the recording / reproducing spot DS and the tracking spot TS are located at the same position, highly accurate tracking is possible.

<6. Modifications><6.1. Solid Immersion Mirror> In the embodiments described above,
As an optical element for generating the near-field light NP1, NP2,
Although the example using the solid immersion lens SIL has been described, the present invention is not limited to this, and the solid immersion mirror SIM may be used as an optical element that generates the near-field lights NP1 and NP2. Here, a specific example of the solid immersion mirror SIM is shown in FIGS.
It is shown in FIG. When the solid immersion mirror SIM is used, since the solid immersion mirror SIM itself has a light condensing function, it is not necessary to provide the first condenser lens 17, and therefore the following description of the case of using the solid immersion mirror SIM is given. Then, the thing except the 1st condensing lens 17 is demonstrated.

20 to 24 are views showing a solid immersion mirror SIM having the same operation as the combination of the solid immersion lens SIL and the first condenser lens 17 shown in FIG.
25 to 29 show the solid immersion lens SI shown in FIG.
FIG. 35 is a diagram showing a solid immersion mirror SIM that exhibits the same operation as that of a combination of L and the first condenser lens 17, and FIGS. 30 to 34 are solid immersion lens SIL shown in FIG. 18.
FIG. 11 is a diagram showing a solid immersion mirror SIM that has the same effect as a combination of the first and the first condenser lens 17. 20 (a), 21 (a), 22 (a), 23 (a), 24 (a), 25 (a), 26 (a), 27 (a), FIG. 28
(a), FIG. 29 (a), FIG. 30 (a), FIG. 31 (a), FIG. 32 (a),
33 (a) and 34 (a) are sectional views of the solid immersion mirror SIM.
20 (b), 21 (b), 22 (b), 23 (b), 24
(b), FIG. 25 (b), FIG. 26 (b), FIG. 27 (b), FIG. 28 (b),
29 (b), 30 (b), 31 (b), 32 (b), 33
20 (b) and FIG. 34 (b) are bottom views of the solid immersion mirror SIM.
(c), FIG. 21 (c), FIG. 22 (c), FIG. 23 (c), FIG. 24 (c),
25 (c), 26 (c), 27 (c), 28 (c), 29
(c), FIG. 30 (c), FIG. 31 (c), FIG. 32 (c), FIG. 33 (c),
FIG. 34 (c) shows a top view of the solid immersion mirror SIM.

<6.1.1. First Specific Example of Solid Immersion Mirror> First, the solid immersion mirror SIM shown in FIG. 20 will be described. In FIG. 20, the solid immersion mirror SIM has a main body 180 made of a high refractive index material such as lanthanum silica glass or lead silica glass, and the first surface 180S, which is the upper surface side of the main body 180, is convex. The second surface 180U, which is formed in a circular shape and is on the lower surface side, is formed in a substantially flat shape. First side 1
A reflection film MI1 for reflecting light inside the solid immersion mirror SIM is formed in the central portion of 80S. A reflective film MI2 for reflecting light inside the solid immersion mirror SIM is also formed on the second surface 180U, and a minute opening 19H is formed near the center of the reflective film MI2. A tracking opening 180H is formed at a position slightly apart from 19H. Incidentally, the reflective film MI2 around the minute opening 19H and the tracking opening 180H.
Is used not for reflection but for shading.
The reflection films MI1 and MI2 are made of Al, Au, Ag, Cu, Ni.
It is formed by a thin film technique such as a well-known sputtering method using a metal material such as.

When the recording / reproducing light DL which is parallel light is incident on the first surface 180S of the solid immersion mirror SIM, the first surface 18S
The light enters the solid immersion mirror SIM from the peripheral portion where the reflective film MI1 of 0S is not formed. The light incident on the inside of the solid immersion mirror SIM receives the reflection film M formed on the second surface 180U.
It is reflected by I2 and further reflected by the reflection film MI1 formed on the first surface 180S. As a result, the recording / reproducing light DL that has entered the solid immersion mirror SIM is condensed near the substantially central portion of the second surface 180U, and its light spot becomes a minute spot compared to the spot formed in the air. . Then, when the minute aperture 19H formed on the second surface 180U of the solid immersion mirror SIM is present at the position where the spot is formed, the near-field light NP1 of the minute light spot oozes out downward from the minute aperture 19H. It will be.

Regarding the tracking light TL, the light flux is slightly inclined with respect to the recording / reproducing light DL, and the solid immersion mirror SI is
After entering the first surface 180S of M and exhibiting reflection similar to that of the recording / reproducing light DL, when performing total reflection at the tracking opening 180H formed on the second surface 180U, tracking is performed on the recording medium 20 side. The near-field light NP2 for light is generated. The generation of the recording / reproducing spot DS, the tracking spot TS, and the recording pit DP is exactly the same as that shown in FIG. Here, since the wavelength of the recording / reproducing light DL and the tracking light TL can be reduced and the numerical aperture can be increased by using the solid immersion mirror, the spot diameter generated by the near-field light NP2 for tracking is reduced. Alternatively, it is possible to increase the throughput of the near-field light NP1 for recording / reproducing in the minute aperture 19H.

<6.1.2. Solid immersion mirror second to fifth
21 to 24 show an example in which the solid immersion mirror SIM shown in FIG. 20 is further modified. 21-
The solid immersion mirror SIM shown in FIG. 24 is made of the same material as the solid immersion mirror SIM shown in FIG. In addition, as for the structure, the second surface 180U, which is the lower surface side of the solid immersion mirror SIM, is the same as the solid immersion mirror SIM shown in FIG.
A reflective film (light-shielding film) MI2 is formed on the surface of FIG.
Except for the solid immersion mirror SIM shown in FIG. 2, a minute opening 19H is formed at a substantially central position of the reflection film (light shielding film) MI2, and a tracking opening 180H is formed at a position slightly apart from the minute opening 19H. . In the solid immersion mirror SIM shown in FIG. 22, a minute opening 19H is formed at a position slightly displaced from the center of the reflection film MI2, and a tracking opening 18 is formed at a position slightly apart from the minute opening 19H.
0H is formed. Note that, here, the positional relationship between the minute aperture 19H and the tracking aperture 180H in the solid immersion mirror SIM shown in FIGS. Further, here, the formation of the recording / reproducing spot DS, the tracking spot TS, and the recording pit DP is the same as that shown in FIG. 20, that is, exactly the same as the case shown in FIG. . Therefore, here, the same reference numerals are given to the same parts as those in FIG. 20, and the description thereof will be omitted. In addition, FIGS.
The structure of the solid immersion mirror SIM shown in is slightly different from the structure of the solid immersion mirror SIM shown in FIG. 20, and due to the difference in this structure, the recording / reproducing light DL and the tracking light TL are included.
The optical path of is also slightly different. The features will be briefly described below together with the respective differences.

<6.1.3. Second Specific Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 21, the first surface 180S, which is the upper surface side of the main body 180, is formed in a spheroidal shape, and the concave surface 180D is formed substantially in the center. Has been done. The second surface 180U, which is the lower surface side, is formed in a substantially flat shape. A reflection film MI1 for reflecting light inside the solid immersion mirror SIM is formed on a portion of the first surface 180S other than the recessed portion 180D. Therefore, here, when the recording / reproducing light DL that is parallel light is incident on the first surface 180S of the solid immersion mirror SIM, the solid immersion mirror SIM is projected from the recessed portion 180D of the first surface 180S where the reflective film MI1 is not formed. It is incident on the inside. After that, similarly to the description in FIG. 20, the near-field light NP1 is reflected inside the solid immersion mirror SIM, and as a result, the near-field light NP1 seeps out to the lower side. Also, the tracking light TL
As to the recording / reproducing light DL, when the tracking light TL is incident on the recess 180D of the solid immersion mirror SIM after slightly inclining the light flux with respect to the recording / reproducing light DL, after the same reflection as the recording / reproducing light DL is shown, Near-field light NP2 for tracking is generated on the recording medium 20 side when totally reflected by the tracking opening 180H formed on the second surface 180U.
Here, due to the structure of the solid immersion mirror SIM, the second surface 180U
It is possible to increase the numerical apertures of the recording / reproducing light DL and the tracking light TL that form a spot at
It is possible to increase the throughput of recording / reproducing light in the minute opening 19H. Further, since the tracking spot TS generated above the recording medium 20 can be made small, the radial width of the groove portion 20G of the recording medium 20 necessary for tracking can be made narrow, so that the recording density is increased. It is possible to

<6.1.4. Third Specific Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 22, the first surface 180S that is the upper surface side of the main body 180 is formed in a paraboloid of revolution, and the second surface 180U that is the lower surface side. Is substantially flat, and the third surface 180W, which is the side surface portion, is substantially flat. A reflective film MI1 for reflecting light inside the solid immersion mirror SIM is formed on the entire first surface 180S. Here, on the third surface 180W of the solid immersion mirror SIM, the recording / reproducing light DL that is parallel light is solid immersion mirror S.
When entering the IM, the light entering the solid immersion mirror SIM is reflected by the reflective film MI1 formed on the first surface 180S. As a result, the recording / reproducing light DL that has entered the solid immersion mirror SIM is condensed on the minute opening 19H, and the near-field light NP1 oozes out to the lower side. Also, with respect to the tracking light TL, when the light flux is slightly inclined with respect to the recording / reproducing light DL and is incident on the third surface 180W of the solid immersion mirror SIM, after exhibiting the same reflection as the recording / reproducing light DL. The near-field light NP2 for tracking is generated on the recording medium 20 side when totally reflected by the tracking opening 180H formed in the second surface 180U.

In FIG. 22, the recording / reproducing light DL shown in FIG.
The positional relationship between the recording medium 20 and the incident direction of the tracking light TL with respect to the optical element peripheral part 3 is different. It is assumed that the entire information recording / reproducing apparatus A is arranged so as to be in a direction substantially orthogonal to. Therefore, here, the incident directions of the recording / reproducing light DL and the tracking light TL with respect to the optical element peripheral portion 3 can be made substantially parallel to the radial direction of the recording medium 20.

<6.1.5. Fourth Specific Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 23, the first surface 180S that is the upper surface side of the main body 180 is formed in a substantially flat shape, and the second surface 180U that is the lower surface side is rotated. It is formed in a parabolic shape. A reflection film MI1 for reflecting light inside the solid immersion mirror SIM is formed at the center of the first surface 180S. Here, when the recording / reproducing light DL which is parallel light is incident on the first surface 180S of the solid immersion mirror SIM, the first surface 1
Light enters the solid immersion mirror SIM from the peripheral portion of the 80S where the reflective film MI1 is not formed. After that, similar to the description in FIG. 20, the light is reflected inside the solid immersion mirror SIM, and as a result, the near-field light NP1 is emitted from the minute aperture 19H.
Will seep out to the lower side. Also, with respect to the tracking light TL, when the light flux is slightly inclined with respect to the recording / reproducing light DL and is incident on the first surface 180S of the solid immersion mirror SIM, after exhibiting the same reflection as the recording / reproducing light DL. ,
Tracking opening 180 formed on the second surface 180U
When total reflection is performed at H, the near-field light NP2 for tracking is generated on the recording medium 20 side. In addition, here, in the second surface 180U, a portion where the minute opening 19H and the tracking opening 180H are present is the recording medium 20.
It may be a plane parallel to the surface of the. This is to prevent the position where the near-field light NP2 is generated from being too far away from the recording medium 20 so that tracking by the near-field light NP2 becomes impossible. In addition, here, the second surface 180U of the solid immersion mirror SIM is formed into a paraboloid of revolution, so that the second surface 180U is larger than the solid immersion mirror SIM shown in FIG.
Since the portion where the surface 180U approaches the recording medium 20 is reduced, the mounting accuracy of the solid immersion mirror SIM is relaxed.

<6.1.6. Fifth Specific Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 24, the first surface 180S that is the upper surface side of the main body 180 is formed in a substantially flat shape, and the second surface 180U that is the lower surface side is substantially The third surface 180W, which is a flat surface and is a side surface, is formed in a paraboloid of revolution. Here, the first surface 180S is relatively larger in area than the second surface 180U, and the third surface 180W also has a reflective film MI for reflecting light inside the solid immersion mirror SIM.
3 is formed. Therefore, here, when the recording / reproducing light DL, which is parallel light, is incident on the first surface 180S of the solid immersion mirror SIM, the recording / reproducing light DL is reflected by the third surface 180W and enters the minute opening 19H formed in the second surface 180U. Collect light.
Note that the incident light of the solid immersion mirror SIM is entirely provided by the provision of the light shielding member 150, so that all of the incident light of the third solid immersion mirror SIM is incident.
It is assumed that it has been previously shaped into a beam shape that is reflected by the surface 180W. However, here again, the small aperture 19
Since the recording / reproducing light DL is condensed on H, the minute opening 19
The near-field light NP1 oozes out from H to the lower side. As for the tracking light TL, the light flux is slightly inclined with respect to the recording / reproducing light DL, and the solid immersion mirror SIM is used.
When the light is incident on the first surface 180S of the above, after exhibiting the same reflection as the recording / reproducing light DL, when the light is totally reflected by the tracking opening 180H formed on the second surface 180U,
Near-field light NP2 for tracking is generated on the recording medium 20 side. Here, due to the structure of the solid immersion mirror SIM, the recording / reproducing light D that forms a spot on the second surface 180U.
The numerical apertures of L and the tracking light TL are increased,
It is possible to improve the throughput of recording / reproducing light in the minute opening 19H. Further, the spot of the tracking light TL formed on the recording medium 20 can be reduced.

<6.1.7. Sixth Concrete Example of Solid Immersion Mirror> The solid immersion mirror SIM shown in FIG. 25 has many parts similar to those of the solid immersion mirror SIM shown in FIG. 20. The difference lies in the lower surface of the solid immersion mirror SIM. On the surface 180U, the tracking opening 180H is formed, but the tracking small opening 19Hb is formed, and the small opening 19H for generating the near-field light NP1 for recording and reproduction is formed. Minute aperture 19 for recording and reproduction
Only the point where the name is changed to Ha and the point where the optical path of the tracking light TL is changed accordingly.
Since the positional relationship between a and 19Hb is the same as that shown in FIG. 16, description thereof will be omitted. Further, in FIG. 25, the same parts as those in FIG. 20 are designated by the same reference numerals, and the description thereof will be omitted.

Here, the tracking light TL is slightly tilted with respect to the recording / reproducing light DL, and the solid immersion mirror SI is
When the light is incident on the first surface 180S of M, the light enters the solid immersion mirror SIM from the peripheral portion of the first surface 180S where the reflection film MI1 is not formed. The light incident on the inside of the solid immersion mirror SIM is reflected by the reflection film MI2 formed on the second surface 180U, and further, the reflection film MI formed on the first surface 180S.
Reflect at 1. As a result, the tracking light TL incident on the solid immersion mirror SIM is condensed on the tracking minute opening 19Hb formed on the second surface 180U, and the near-field light N is moved downward from the tracking minute opening 19Hb.
P2 oozes out. Here, the recording / reproducing spot DS,
Since the formation of the tracking spot TS and the recording pit DP is exactly the same as that shown in FIG. 16, it is omitted here. Here, by using the solid immersion mirror, the recording / reproducing light DL and the tracking light TL are used.
Since the wavelength can be reduced and the numerical aperture can be increased, the spot diameter generated by the near-field light NP2 for tracking is reduced, and the throughput of the near-field light NP1 for recording and reproduction in the minute aperture 19Ha is increased. You can

<6.1.8. 7th ~ 1st of solid immersion mirror
Specific Example of 0> FIGS. 26 to 29 show an example in which the solid immersion mirror SIM shown in FIG. 25 is further modified. FIG. 26
The solid immersion mirror SIM shown in FIG. 29 is made of the same material as the solid immersion mirror SIM shown in FIG. Further, regarding the structure, as in the solid immersion mirror SIM shown in FIG. 25 except for the solid immersion mirror SIM shown in FIG. The film (light-shielding film) MI2 is formed, and the reflective film (light-shielding film) MI2 is formed with a minute opening 19Ha for recording and reproduction and a minute opening 19Hb for tracking. Further, in FIG. 27, as compared with the case of the solid immersion mirror SIM shown in FIG. 25, the minute opening 19Ha for recording and reproduction is provided.
The position where the minute opening 19Hb for tracking is formed is slightly deviated, but the minute opening 19Hb for recording and reproduction is formed.
The positional relationship between a and the minute opening 19Hb for tracking is the same as in FIG.

Incidentally, here, the recording / reproducing spot D is used.
S, tracking spot TS, and recording pit D
The formation of P is the same as that shown in FIG. 25, that is, exactly the same as the case shown in FIG. In addition, here, the same portions as those in FIG. 25 are denoted by the same reference numerals, and description thereof will be omitted.

The structure of the solid immersion mirror SIM shown in FIGS. 26 to 29 is the same as the structure of the solid immersion mirror SIM shown in FIGS. 21 to 24 except for the second surface 180U. Since the optical path of the light DL is also the same, the description thereof is omitted, but the optical path of the tracking light TL is slightly different due to the difference of the second surface 180U. The differences and features of each will be briefly described below.

<6.1.9. Seventh Concrete Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 26, when the tracking light TL is slightly inclined with respect to the recording / reproducing light DL and is incident on the first surface 180S of the solid immersion mirror SIM. , The recessed portion 18 of the first surface 180S where the reflective film MI1 is not formed.
After entering the solid immersion mirror SIM from 0D and showing the same reflection as the tracking light TL shown in FIG.
Microscopic aperture 19 for tracking formed on surface 180U
A small aperture 1 for tracking that creates a spot on Hb
The near-field light NP2 oozes out from 9Hb to the lower side. Here, due to the structure of the solid immersion mirror SIM, the numerical apertures of the recording / reproducing light DL and the tracking light TL that form spots on the second surface 180U are increased so that the recording / reproducing minute aperture 19Ha is close to the recording / reproducing area. The throughput of the field light NP1 can be increased. In addition, the recording medium 2
The tracking spot TS generated above 0 can also be made small.

<6.1.10. Eighth Concrete Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 27, when the tracking light TL is slightly inclined with respect to the recording / reproducing light DL and is incident on the third surface 180W of the solid immersion mirror SIM. , Fig. 2
After exhibiting the same reflection as the tracking light TL shown in FIG. 2, a spot is generated on the tracking minute opening 19Hb formed on the second surface 180U, and the near-field light NP2 is downward from the tracking minute opening 19Hb. Soak into. In FIG. 27, the positional relationship between the recording medium 20 and the incident direction of the recording / reproducing light DL and the tracking light TL shown in FIG. 3 with respect to the optical element is different, but here, the recording / reproducing light DL and the tracking light are different. It is assumed that the entire information recording / reproducing apparatus A is arranged such that the incident direction of the TL with respect to the optical element is substantially orthogonal to FIG. Therefore, here, the incident directions of the recording / reproducing light DL and the tracking light TL with respect to the optical element can be made substantially parallel to the radial direction of the recording medium 20.

<6.1.1.1. Ninth Specific Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 28, when the tracking light TL is slightly inclined with respect to the recording / reproducing light DL and is incident on the first surface 180S of the solid immersion mirror SIM. , Fig. 2
After exhibiting the same reflection as the tracking light TL shown in FIG. 3, a spot is generated on the tracking minute aperture 19Hb formed on the second surface 180U, and the near-field light NP2 oozes out to the lower side. The portion of the second surface 180U having the minute opening 19Ha for recording and reproduction and the minute opening 19Hb for tracking may be a surface parallel to the recording medium 20. This is to prevent the position where the near-field light NP2 is generated from being too far away from the recording medium 20 so that tracking by the near-field light NP2 becomes impossible. Here, the second surface 1 of the solid immersion mirror SIM
By making 80U into a paraboloid of revolution, compared to the solid immersion mirror SIM shown in FIG. 25, the portion where the second surface 180U approaches the recording medium 20 is reduced, so that the solid immersion mirror SIM is attached. Accuracy is relaxed.

<6.1.12. Tenth Specific Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 29, the tracking light TL is slightly tilted with respect to the recording / reproducing light DL,
When the light is incident on the first surface 180S of the solid immersion mirror SIM, it shows the same reflection as the recording / reproducing light DL, and then the second surface 18S.
A spot is generated on the tracking minute opening 19Hb formed at 0U, and the tracking minute opening 19Hb is formed.
The near-field light NP2 oozes out from the lower side. Here, due to the structure of the solid immersion mirror SIM, the numerical apertures of the recording / reproducing light DL and the tracking light TL forming a spot on the second surface 180U are large, and the throughput of the recording / reproducing light in the minute aperture 19H is improved. Can be achieved. Further, the spot of the tracking light TL formed on the recording medium 20 can be reduced.

<6.1.13. Eleventh Specific Example of Solid Immersion Mirror> The solid immersion mirror SIM shown in FIG. 30 has many parts similar to those of the solid immersion mirror SIM shown in FIG. 20, and the difference lies in the lower surface of the solid immersion mirror SIM. Surface 180U
And the accompanying change in the optical path of the tracking light TL. Further, here, it is assumed that the wavelengths of the recording / reproducing light DL and the tracking light TL which are incident on the solid immersion mirror SIM are different. Note that, in FIG. 30, portions similar to those in FIG. 20 are denoted by the same reference numerals, and description thereof will be omitted.

First, the structure of the solid immersion mirror SIM shown in FIG. 30 will be described. Here, the second surface 180U on the lower surface side of the solid immersion mirror SIM shown in FIG.
A reflection film MI2 for reflecting light is formed inside the solid immersion mirror SIM except for a substantially central portion of 80U, and a substantially central portion of the second surface, that is, the reflective film MI2 is not formed. Light-transmitting film 190 for tracking on a part
Are formed. Furthermore, the light transmitting film for tracking 1
A minute opening 19H is formed near the center of 90.
The tracking light transmission film 190 has a property of selectively transmitting light depending on the wavelength of light, and is formed of a dichroic film or the like. Here, the tracking light transmission film 190 does not transmit the light of the wavelength of the recording / reproducing light DL, but transmits the light of the wavelength of the tracking light TL. In addition, here, the light transmitting film 1 for tracking is used.
90 does not transmit the light having the wavelength of the recording / reproducing light DL, but reflects or absorbs the light.

Next, 52, the tracking light TL will be described. The tracking light TL is formed on the first surface 180S of the solid immersion mirror SIM almost in parallel with the recording / reproducing light DL.
Is incident, the light is incident on the inside of the solid immersion mirror SIM from the peripheral portion of the first surface 180S where the reflection film MI1 is not formed. The light incident on the inside of the solid immersion mirror SIM is the second surface 1
It is reflected by the reflective film MI2 formed on 80U,
The light is reflected by the reflective film MI1 formed on the surface 180S. As a result, the tracking light T incident on the solid immersion mirror SIM
When the L is totally reflected in the area where the minute opening 19H is formed in the tracking light transmission film 190 formed near the center of the second surface 180U, the near field light NP2 for tracking is recorded on the recording medium 20. Raise to the side. here,
Recording / playback spot DS, tracking spot T
The formation of S and the recording pit DP is exactly the same as in the case shown in FIG. 18, and is therefore omitted here. Here, by using the solid immersion mirror, the recording / reproducing light DL is
Since the wavelength of the tracking light TL can be reduced and the numerical aperture can be increased, the spot diameter generated by the near-field light NP2 for tracking can be reduced, and the small aperture 19 can be formed.
The throughput of the near-field light NP1 for recording and reproduction in H can be increased.

<6.1.14. 12th of solid immersion mirror
Fifteenth Specific Example> FIGS. 31 to 34 show an example in which the solid immersion mirror SIM shown in FIG. 30 is further modified. The solid immersion mirror SIM shown in FIGS. 31 to 34 is made of the same material as the solid immersion mirror SIM shown in FIG. Further, regarding the structure, as in the solid immersion mirror SIM shown in FIG. 30, except for the solid immersion mirror SIM shown in FIG. 32, the second surface 180U on the lower surface side of the solid immersion mirror SIM has a second surface.
The solid immersion mirror SI except for the substantially central portion of the surface 180U
A reflection film MI2 for reflecting light is formed inside M, and the reflection film MI2 is formed in the substantially central portion of the second surface.
The light-transmitting film 1 for tracking is formed on the portion where 2 is not formed.
90 is formed. Further, a minute opening 19H is formed near the center of the tracking light transmitting film 190. Further, in the solid immersion mirror SIM shown in FIG. 30,
The light transmitting film 190 for tracking is formed substantially in the center of the second surface 180U, and the minute opening 19H is formed near the center of the light transmitting film 190 for tracking. With respect to the solid immersion mirror SIM shown in FIG. The tracking light transmission film 190 is formed on the entire second surface 180U, and the minute opening 19H is formed at a position slightly deviated from the vicinity of the approximate center of the tracking light transmission film 190.

Incidentally, here, the recording / reproducing spot D is used.
S, tracking spot TS, and recording pit D
The generation of P is the same as that shown in FIG. 30, that is, exactly the same as the case shown in FIG. Further, here, the same parts as those in FIG. 30 are designated by the same reference numerals, and the description thereof will be omitted.

Next, the solid immersion mirror S shown in FIGS.
The IM structure is the same as in FIGS. 21 to 24 except for the second surface 180U.
The structure is the same as that of the solid immersion mirror SIM shown in
Further, since the optical path of the recording / reproducing light DL is also the same, the description thereof is omitted, but the optical path of the tracking light TL is slightly different due to the difference of the second surface 180U. The differences and features of each will be briefly described below.

<6.1.15. Twelfth Specific Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 31, the tracking light TL is substantially parallel to the recording / reproducing light DL.
When the light is incident on the first surface 180S of the solid immersion mirror SIM, the light is incident on the inside of the solid immersion mirror SIM from the recess 180D of the first surface 180S where the reflection film MI1 is not formed, and is similar to the tracking light TL shown in FIG. After showing a perfect reflection,
The light transmitting film 1 for tracking formed on the second surface 180U
Near-field light NP2 for tracking is generated on the recording medium 20 side when total reflection is performed in a region in which the minute aperture 19H is formed in 90. Here, due to the structure of the solid immersion mirror SIM, the numerical apertures of the recording / reproducing light DL and the tracking light TL that form spots on the second surface 180U are increased, and the near-field light NP1 for recording / reproducing in the minute aperture 19H is increased. Throughput can be increased. Also, the tracking spot TS formed on the recording medium 20 can be made small.

<6.1.16. Thirteenth Concrete Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 32, the tracking light TL is substantially parallel to the recording / reproducing light DL,
When the light is incident on the third surface 180W of the solid immersion mirror SIM, it shows the same reflection as the tracking light TL shown in FIG. 22, and then a minute portion of the tracking light transmission film 190 formed on the second surface 180U. Near-field light NP2 for tracking is generated on the recording medium 20 side when the light is totally reflected in the area where the opening 19H is formed. In FIG. 32, FIG.
The positional relationship between the recording medium 20 and the incident direction of the recording / reproducing light DL and the tracking light TL with respect to the optical element is different. Here, the recording / reproducing light DL and the tracking light TL are incident on the optical element. It is assumed that the entire information recording / reproducing apparatus A is arranged so that the direction is substantially orthogonal to FIG. Therefore,
Here, the recording / reproducing light DL and the tracking light T
The incidence direction of the L on the optical element can be made substantially parallel to the radial direction of the recording medium 20.

<6.1.17. Fourteenth Concrete Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 33, the tracking light TL is substantially parallel to the recording / reproducing light DL.
When the light is incident on the first surface 180S of the solid immersion mirror SIM, it shows the same reflection as the tracking light TL shown in FIG. 23, and then the minute opening 19H of the tracking light transmission film 190 formed on the second surface 180U. Near-field light NP2 for tracking is generated on the recording medium 20 side when the light is totally reflected in the area in which is formed. The portion of the second surface 180U on which the tracking light transmission film 190 is provided may be a surface parallel to the recording medium 20. This is to prevent the position where the near-field light NP2 is generated from being too far away from the recording medium 20 so that tracking by the near-field light NP2 becomes impossible. Here, by making the second surface 180U of the solid immersion mirror SIM into a paraboloid of revolution, the second surface 180U approaches the recording medium 20 as compared with the solid immersion mirror SIM shown in FIG. Since the number of parts is reduced, the mounting accuracy of the solid immersion mirror SIM is relaxed.

<6.1.18. Fifteenth Specific Example of Solid Immersion Mirror> In the solid immersion mirror SIM shown in FIG. 34, the tracking light TL is substantially parallel to the recording / reproducing light DL,
When the light is incident on the first surface 180S of the solid immersion mirror SIM, it shows the same reflection as the tracking light TL shown in FIG. 24, and then the minute aperture 19H of the tracking light transmission film 190 formed on the second surface 180U. Near-field light NP2 for tracking is generated on the recording medium 20 side when the light is totally reflected in the area in which is formed. Here, solid immersion mirror SI
Due to the structure of M, the numerical apertures of the recording / reproducing light DL and the tracking light TL forming a spot on the second surface 180U are large, and the throughput of recording / reproducing light in the minute aperture 19H can be improved. Further, the spot of the tracking light TL formed on the recording medium 20 can be reduced.

<7. Others> In the above-described embodiment, the light that causes the tracking spot TS on the recording medium 20 is all near-field light, but the present invention is not limited to this, and the tracking light TL is not limited to this. The tracking light TL is transmitted as propagating light at the position where the near-field light NP2 is generated on the recording medium 20 side when totally reflected by the plane portions 18U and 180U of the optical element, and the propagating light is transmitted. The spot generated on the recording medium 20 may be used as a spot for tracking the recording medium 20.

Further, in the above-described embodiment, the near-field light NP1 for recording and reproduction is all the minute openings 19H, 19H.
Although it is the near-field light generated in a, it is not limited to this, and the thin film 19 or the tracking light transmitting film 190 in the region where the minute openings 19H and 19Ha are formed.
And the near-field light NP1 is generated when the recording / reproducing light DL is focused on the bottom surface of the optical element, for example, the flat surface portion 18U of the solid immersion lens SIL or the flat surface portion 180U of the solid immersion mirror SIM in that region. It may be something like this. Examples of such a structure include structures such as minute dielectrics and metal projections.

In the embodiment shown in FIGS. 16 and 25 to 29, the near-field light NP2 for tracking is used.
Although only one microscopic aperture 19Hb for tracking that causes the light is generated, the present invention is not limited to this, and the proximity generated when the tracking light TL is totally reflected in the flat surface portion 18U in FIGS. Field light N
As the relative positional relationship between the spot of P2 and the near-field light NP1 for recording and reproduction is changed stepwise, a plurality of microscopic apertures 19Hb for tracking are provided so that the near-field light NP2 for tracking is generated. Micro aperture 1
9Hb is changed stepwise, and a minute opening 19 for recording / reproduction is used.
The relative positional relationship between the near-field light NP1 generated from Ha and the near-field light NP2 generated from the tracking minute opening 19Hb may be changed stepwise.

In the specific examples using the solid immersion mirror SIM shown in FIGS. 20 to 24, the tracking aperture 1 for generating the near-field light NP2 for tracking is used.
Although only one 80H is provided, the present invention is not limited to this, and the flat surface portion 18 in FIGS.
The near-field light NP2 spot generated when the tracking light TL is totally reflected at U and the near-field light N for recording and reproduction
As if the relative positional relationship with P1 was changed stepwise,
A plurality of tracking openings 180H are provided so that tracking near-field light NP2 is generated.
80H is changed stepwise, and a minute opening 19 for recording / reproduction is used.
The relative positional relationship between the near-field light NP1 generated from Ha and the near-field light NP2 generated from the tracking opening 180H may be changed stepwise.

In the second specific example of the optical element peripheral portion 3 shown in FIGS. 9 and 10, the recording / reproducing light DL and the tracking light T are emitted from the same light source as shown in FIG.
When L is obtained, +1 generated in the diffraction grating 12
Only the second-order diffracted light is used as the tracking light TL, and in order to change the position where the tracking light TL enters the solid immersion lens SIL, the tracking light adjusting unit 2
In the above, the optical path of the tracking light TL is shifted, but the present invention is not limited to this, and the -1st order diffracted light generated in the diffraction grating 12 is used as another tracking light T.
It may be configured to be used as L and to switch and use two tracking lights (+ 1st order diffracted light and −1st order diffracted light).

The specific embodiments described above include inventions having the following configurations.

(1) An optical element used when producing an optical action with a recording medium having a tracking pattern, wherein the second light of the first and second light supplied is used. A micro-aperture for generating near-field light for recording and reproduction based on the first light, and having the optical characteristic of selectively transmitting the second light, and totally reflecting the second light. Accordingly, an optical element comprising: a filter that generates near-field light for tracking for detecting the tracking pattern; and a support body that supports the filter.

With this structure, the recording / reproducing spot is reduced by the near-field light for recording / reproducing that occurs in the minute aperture, so that it is possible to record or reproduce information with high resolution or high density. Further, since the tracking light is near-field light due to the total reflection light, and the tracking spot is also small, it is possible to narrow the area required for tracking in the recording medium. Further, the position of the minute aperture and the position where the near-field light for tracking is generated can be made to be the same, and as a result, the position to perform the tracking and the recording / reproducing on the recording medium can be made to be the same, so that the accurate tracking can be performed. Is possible.

(2) An information recording / reproducing apparatus for recording information on a recording medium having a tracking pattern or reproducing the information recorded on the recording medium by using near-field light. And a light supply means for supplying a second light,
(b) Near-field light for recording and reproducing for recording information on the recording medium or reproducing information recorded on the recording medium by receiving the first and second lights, and the tracking An optical element for respectively generating a near-field light for tracking for detecting a pattern, wherein the optical element is transparent to the second light, while blocking the first light. Have the characteristics of
A first region in which a minute aperture for generating the near-field light for recording and reproduction is formed, and a second region in which the near-field light for tracking is generated by totally reflecting the second light. An information recording / reproducing apparatus comprising:

With this structure, the spot of the near-field light for recording and reproduction generated in the minute aperture becomes minute, so that the recording density can be improved. Further, since the near-field light for recording / reproducing and the near-field light for tracking can be generated at the same position, the spots of near-field light for tracking and recording / reproducing can be made to be at the same position on the recording medium. Therefore, tracking can be performed with high accuracy.

(3) An information recording / reproducing apparatus having the invention of any one of claims 1 to 4 or the structure of (2), wherein the first area and the second area are shared. An information recording / reproducing apparatus characterized by:

With this configuration, since the near-field light for recording / reproducing and the near-field light for tracking are generated at the same position, the spots of the near-field light for tracking and the near-field light for recording / reproducing are at the same position on the recording medium. Therefore, tracking can be performed with high accuracy.

(4) An information recording / reproducing apparatus having the invention of any one of claims 1 to 4 or the configuration of (2), wherein the spot of near-field light for tracking is near-field light for recording / reproduction. An information recording / reproducing apparatus, characterized in that it is formed in the range of occurrence of

With this configuration, accurate tracking is possible.

(5) In the invention of claim 6, the tracking pattern is formed by alternately arranging a recording / reproducing area and a tracking area which are distinguished from each other in a predetermined direction, and the optical element is a recording element. An information recording / reproducing apparatus, wherein a near-field light spot for reproduction is generated on a recording / reproducing area, and a near-field light spot for tracking is generated above a tracking area.

With this structure, the width of the recording / reproducing area can be narrowed to about the diameter of the spot generated by the near-field light for recording / reproducing generated in the minute opening, that is, the diameter of the minute opening, and recording on the recording medium. The density can be improved.

(6) In the invention of claim 7, the tracking pattern is formed by alternately arranging a recording / reproducing area and a tracking area, which are distinguished from each other, in a predetermined direction, and the optical element is a recording element. A near-field light spot for reproduction is generated on the recording / reproducing area, and a near-field light spot for tracking is generated on the tracking area. By gradually changing the relative positional relationship between the spot of the field light and the spot of the near-field light for tracking into a plurality of positional relationships, the near-field for the recording / reproducing in the predetermined direction of the recording / reproducing area. An information recording / reproducing apparatus capable of changing the position of a light spot without jumping over the tracking area.

With this structure, the recording density in the recording / reproducing area of the recording medium can be improved, and as a result, the recording density of the entire recording medium can be improved.

(7) In the information recording / reproducing apparatus having the structure of (2), the wavelength of the second light is relatively longer than the wavelength of the first light.

With this configuration, since the wavelength of the first light can be set to be relatively short, it is possible to increase the throughput of the near-field light for recording / reproducing in the minute aperture, and to achieve higher resolution and higher speed. Recording and reproduction becomes possible.

(8) In the information recording / reproducing apparatus having the structure of (2), the wavelength of the first light is relatively longer than the wavelength of the second light.

With this configuration, since the wavelength of the second light can be set to be relatively short, the spot of the near-field light for tracking becomes small, and the area required for tracking on the recording medium can be narrowed. Therefore, the recording density can be improved.

(9) In the invention of claim 8, the optical system is characterized in that the first and second regions are provided in the solid immersion lens.

Since the wavelengths of the first and second lights can be reduced by using the solid immersion lens, the spot diameter generated by the near-field light for tracking can be reduced, and the proximity for recording / reproduction in a minute aperture can be reduced. The field light throughput can be increased.

(10) In the invention of claim 8, the single condensing element is a solid immersion mirror, and the first region and the second region are provided in the solid immersion mirror. Optical system to do.

By using the solid immersion mirror, the wavelengths of the first and second lights can be reduced and the numerical aperture can be increased. Therefore, the spot diameter generated by the near-field light for tracking can be reduced and the fine aperture can be reduced. It is possible to increase the throughput of the near-field light for recording / reproducing in.

(11) In the invention of claim 9, the optical element is characterized in that the first and second regions are provided in the solid immersion lens.

Since the wavelengths of the first and second lights can be reduced by using the solid immersion lens, the spot diameter generated by the near-field light for tracking is reduced, and the proximity for recording / reproduction in a minute aperture is reduced. The throughput of field light can be increased, and light of the same wavelength can be used for tracking and recording / reproducing.

(12) In the invention of claim 9, the optical element is characterized in that the first and second regions are provided in the solid immersion mirror.

By using the solid immersion mirror, the wavelengths of the first and second lights can be reduced and the numerical aperture can be increased. Therefore, the spot diameter generated by the near-field light for tracking can be reduced, and the fine aperture can be reduced. It is possible to increase the throughput of the near-field light for recording / reproducing in, and to use the light of the same wavelength for tracking and recording / reproducing.

(13) In the invention of claim 10, the optical element is characterized in that the first and second regions are provided in the solid immersion lens.

Since the wavelengths of the first and second lights can be reduced by using the solid immersion lens, the spot diameter for generating the near-field light for tracking is reduced, and the proximity for recording / reproduction in a minute aperture is reduced. The field light throughput can be increased.

(14) In the invention of claim 10, the optical element is characterized in that the first and second regions are provided in the solid immersion mirror.

By using the solid immersion mirror, the wavelengths of the first and second lights can be reduced and the numerical aperture can be increased, so that the spot diameter generated by the near-field light for tracking can be reduced and a small aperture can be formed. It is possible to increase the throughput of the near-field light for recording / reproducing in.

(15) An optical element having the structure of (1), wherein the support for supporting the filter is a solid immersion lens.

Since the wavelengths of the first and second lights can be reduced by using the solid immersion lens, the spot diameter generated by the near-field light for tracking can be reduced, and the proximity for recording / reproduction in a minute aperture can be reduced. The field light throughput can be increased.

(16) An optical element having the structure of (1), wherein the support for supporting the filter is a solid immersion mirror.

By using the solid immersion mirror, the wavelengths of the first and second lights can be reduced and the numerical aperture can be increased. Therefore, the spot diameter generated by the near-field light for tracking can be reduced, and the fine aperture can be reduced. It is possible to increase the throughput of the near-field light for recording / reproducing in.

(17) An information recording / reproducing apparatus which records information on a recording medium having a tracking pattern or reproduces the information recorded on the recording medium by using near-field light. And a light supply means for supplying a second light,
(b) Near-field light for recording / reproducing for recording information on the recording medium or reproducing the information recorded on the recording medium based on the first and second lights, and the tracking An optical element having a single slit-type opening for generating tracking near-field light for detecting a pattern, respectively, and the first and second lights are the slit-type opening. An information recording / reproducing apparatus characterized in that light is condensed on both ends of the information recording / reproducing apparatus.

With this structure, the spot of the near-field light for tracking generated on the recording medium becomes small, and the area required for tracking on the recording medium can be narrowed. As a result, the recording density on the recording medium is improved. Can be made.

[0187]

As described above, according to the first aspect of the invention, since the recording / reproducing on the recording medium and the detection of the tracking pattern are both performed by the near-field light, the recording / reproducing spot is made small. As a result, the recording pits formed on the recording medium can be reduced and the recording pits can be formed at a high density on the recording medium. Also, by making the tracking spot small, it is necessary for tracking on the recording medium. Since such a region can be narrowed, the recording density of the recording medium can be improved.

According to the second aspect of the invention, the recording pits formed on the recording medium are formed by generating near-field light for recording / reproducing in the minute aperture to reduce the spot for recording / reproducing. Since recording pits can be reduced and high density recording pits can be formed on the recording medium, the recording density can be improved.

According to the third aspect of the present invention, by totally reflecting the second light in the optical element,
Since the near-field light for tracking is generated, a special device for generating the near-field light for tracking is not necessary in the optical element.

According to the invention of claim 4, the near-field light for tracking is also generated in the minute aperture, whereby the spot for tracking is further reduced, and the area required for tracking on the recording medium is reduced. Since the width can be narrowed, the recording density of the recording medium can be improved.

According to the invention described in claim 5, the near-field light for recording / reproducing and the near-field light for tracking are:
Since they occur at different positions, the degree of freedom in selecting the material forming the optical element can be increased regardless of the presence or absence of the minute aperture. Further, light having the same wavelength can be used for recording / reproducing and tracking.

According to the sixth aspect of the invention, recording is performed by relatively changing the angle at which the first light is given to the optical element and the angle at which the second light is given to the optical element. Since near-field light for reproduction and near-field light for tracking can be easily generated at different positions,
The recording / reproducing spot and the tracking spot can be generated at different positions.

According to the invention described in claim 7, by changing the incident angle of the second light to the optical element in a stepwise manner, the near-field light for recording / reproducing and the near-field light for tracking are obtained. Since it is possible to change the relative positional relationship that occurs to a plurality of positional relationships stepwise, the relative positional relationship between the recording / reproducing spot and the tracking spot is changed to a plurality of positional relationships stepwise. be able to.

According to the invention described in claim 8, the near-field light for recording and reproducing generated in the minute aperture, and the second
With the near-field light for tracking due to the total reflection of the light, it is possible to record or reproduce information with high resolution or high density, while reducing the recording pits formed on the recording medium to reduce the recording pit. Since the recording pits can be formed with high density and the spot for tracking becomes small, the area required for tracking on the recording medium can be narrowed, and thus the recording density can be improved. Also, since the near-field light for recording and reproducing and the near-field light for tracking are generated at different positions,
The degree of freedom in selecting the material in the area where the minute opening is formed is increased, and the light-shielding property in the area where the minute opening is formed can be improved. As a result, the spot diameter of the near-field light for recording / reproducing can be reduced or reduced. It is possible to improve the throughput of near-field light for recording and reproduction in the minute aperture. Furthermore, one condensing element condenses both the first and second lights at a predetermined position of the optical element, and the position where the near-field light for recording and reproducing is generated and the position where the near-field light for tracking is generated. Since and can be set close to each other, as a result, the tracking position and the recording / reproducing position on the recording medium can be close to each other, and accurate tracking can be performed.

According to the ninth aspect of the invention, the near-field light for recording / reproducing and the near-field light for tracking are generated by generating the near-field light for recording / reproducing and the near-field light for tracking respectively from different minute apertures. Since the spot can be made minute, the recording density can be improved. Further, light having the same wavelength can be used for tracking and recording / reproducing. Further, since the same optical element is provided with the minute aperture, the recording / reproducing position and the tracking position can be set close to each other, so that accurate tracking becomes possible.

According to the invention described in claim 10,
In an optical element that has a first region in which a minute aperture is formed and is mainly formed of a high refractive index medium, near-field light for recording and reproduction is generated in the minute aperture, so that high resolution or high density is achieved. Information can be recorded or reproduced.
In addition, since near-field light for recording / reproducing and tracking is generated in the same optical element, the recording / reproducing position and the recording / reproducing position on the recording medium can be set close to each other, and accurate tracking becomes possible. . Further, the near-field light for tracking is generated by total reflection of the second light outside the periphery of the first region, so that the degree of freedom in selecting the material of the first region in which the minute aperture is formed is high. Therefore, since the light shielding property of the first region can be improved, it is possible to reduce the spot diameter generated on the recording medium by the near-field light and to improve the throughput of the near-field light for recording / reproducing in the minute aperture. Is possible.

[Brief description of drawings]

FIG. 1 is a diagram conceptually showing an information recording / reproducing apparatus A which is an example of an embodiment of the invention.

FIG. 2 is a diagram showing details of part of the information recording / reproducing apparatus A shown in FIG.

3 is a diagram showing details of part of the information recording / reproducing apparatus A shown in FIG.

FIG. 4 is a diagram showing a second specific example of the light generator 1.

FIG. 5 is a diagram showing a second specific example of the tracking light adjusting unit 2.

FIG. 6 is a diagram showing a third specific example of the tracking light adjusting unit 2.

FIG. 7 is a diagram showing a fourth specific example of the tracking light adjusting unit 2.

FIG. 8 is a diagram showing a first specific example of an optical element peripheral portion 3.

9 is a diagram showing a second specific example of the optical element peripheral portion 3. FIG.

10 is a diagram showing a second specific example of the optical element peripheral portion 3. FIG.

FIG. 11 is a diagram showing a third specific example of the optical element peripheral portion 3.

FIG. 12 is a diagram showing a third specific example of the optical element peripheral portion 3.

FIG. 13 is a diagram showing a third specific example of the optical element peripheral portion 3.

FIG. 14 is a diagram showing a third specific example of the optical element peripheral portion 3.

FIG. 15 is a diagram showing a fourth specific example of the optical element peripheral portion 3.

FIG. 16 is a diagram showing a fifth specific example of the optical element peripheral portion 3.

FIG. 17 is a diagram showing a sixth specific example of the optical element peripheral portion 3.

FIG. 18 is a diagram showing a seventh specific example of the optical element peripheral portion 3.

FIG. 19 is a diagram illustrating a seventh specific example of the optical element peripheral portion 3.

FIG. 20 is a diagram showing a first specific example of a solid immersion mirror SIM.

FIG. 21 is a diagram showing a second specific example of the solid immersion mirror SIM.

FIG. 22 is a diagram showing a third specific example of the solid immersion mirror SIM.

FIG. 23 is a diagram showing a fourth specific example of the solid immersion mirror SIM.

FIG. 24 is a diagram showing a fifth specific example of the solid immersion mirror SIM.

FIG. 25 is a diagram showing a sixth specific example of the solid immersion mirror SIM.

FIG. 26 is a diagram showing a seventh specific example of the solid immersion mirror SIM.

FIG. 27 is a diagram showing an eighth specific example of the solid immersion mirror SIM.

FIG. 28 is a diagram showing a ninth specific example of the solid immersion mirror SIM.

FIG. 29 is a diagram showing a tenth specific example of the solid immersion mirror SIM.

FIG. 30 is a diagram showing an eleventh specific example of the solid immersion mirror SIM.

FIG. 31 is a diagram showing a twelfth specific example of the solid immersion mirror SIM.

FIG. 32 is a diagram showing a thirteenth specific example of the solid immersion mirror SIM.

FIG. 33 is a diagram showing a fourteenth specific example of the solid immersion mirror SIM.

FIG. 34 is a diagram showing a fifteenth specific example of the solid immersion mirror SIM.

[Explanation of symbols]

1 Light generator 2 Tracking light adjustment unit 3 Optical element periphery 4 Optical recording medium container 19 thin film 19H, 19Ha, 19Hb Micro aperture 19S slit-shaped opening 20 recording media 20L land section 20G groove part 50 movable parallel plates 51 Rotating axis rod 180H tracking aperture 190 Light-transmitting film for tracking A Information recording / reproducing device CONT tracking controller DL recording / reproducing light DS recording / playback spot DP recording pit M Near-field light generator driving device MR rotation motor controller NE near-field light generator NP1, NP2 near-field light OS external output device SIL solid immersion lens SIM solid immersion mirror TL tracking light TS tracking spot

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5D090 AA01 CC16 FF02 FF11 FF31                 5D118 AA14 BA01 CD03 CG24 CG26                       DA33                 5D119 AA22 BA01 EA02 FA08 JA34                 5D789 AA22 BA01 CA21 CA22 CA23                       EA02 FA08 JA34 JA66

Claims (10)

[Claims] 1. An information recording / reproducing apparatus for recording information on a recording medium having a tracking pattern or reproducing the information recorded on the recording medium by using near-field light, comprising: (a) first and A light supply means for supplying a second light; and (b) a near-field light for recording and reproducing for recording information on the recording medium or reproducing the information recorded on the recording medium. Optical element having a first region generated based on the second light, and a second region generating tracking near-field light for detecting the tracking pattern based on the second light. An information recording / reproducing apparatus comprising: 2. The information recording / reproducing apparatus according to claim 1, wherein a minute opening for generating the near-field light for recording / reproducing is formed in the first area. Information recording / reproducing apparatus. 3. The information recording / reproducing apparatus according to claim 1, wherein the near-field light for tracking totally reflects the second light in the second region. An information recording / reproducing apparatus characterized by being generated by causing it. 4. The information recording / reproducing apparatus according to claim 1, wherein a minute aperture for generating the near-field light for tracking is formed in the second region. An information recording / reproducing apparatus characterized by being provided. 5. The information recording / reproducing apparatus according to claim 1, wherein the first area and the second area do not overlap with each other. Information recording / reproducing apparatus. 6. The information recording / reproducing apparatus according to claim 5, wherein the light supply unit supplies the first light to the optical element at an angle,
An information recording / reproducing apparatus comprising: an optical adjusting unit that relatively changes the angle at which the light is given to the optical element. 7. The information recording / reproducing apparatus according to claim 5, wherein the optical supply unit changes the incident angle of the second light to the optical element in a stepwise manner. An information recording / reproducing apparatus, comprising: an optical adjusting unit capable of changing the relative positional relationship between the area and the second area in a stepwise manner into a plurality of positional relationships. 8. An optical system used for producing an optical action with a recording medium having a tracking pattern, wherein information is recorded on the recording medium or information recorded on the recording medium. A first area in which a minute opening for generating near-field light for recording / reproduction for reproducing is generated based on the first light; and a second area provided outside the first area. Second region that totally reflects the light of the above to generate near-field light for tracking for detecting the tracking pattern, and guides the first light to the minute aperture, And a single light-collecting element that guides the light to the second region. 9. An optical element used for producing an optical action with a recording medium having a tracking pattern, wherein information is recorded on the recording medium or information recorded on the recording medium. And a minute area for generating a near-field light for tracking for detecting the tracking pattern. And a second region having an opening formed therein. 10. An optical element used when an optical action is produced between a recording medium having a tracking pattern, the main body being formed of a high refractive index medium, and information for the recording medium. A first region in which a minute opening is formed for generating near-field light for recording / reproduction for recording or reproducing information recorded in the recording medium, based on the first light; A second region which is provided outside the first region and which totally reflects the second light to generate near-field light for tracking for detecting the tracking pattern. element.