JP4335898B2 - Information recording device - Google Patents

Description

  The present invention relates to an information recording apparatus that performs recording using an information recording medium.

  As an optical recording medium, a disk-shaped optical recording medium is well known as typified by a compact disk, but with the era of digital broadcasting and the like, a recording system with a larger capacity is required. In order to increase the density, it is necessary to reduce the recording pits in which information is recorded. For this purpose, it is necessary to reduce the light and the aperture light spot. Since the spot diameter of light is proportional to λ / NA where λ is the wavelength and NA is the aperture ratio of the lens, it is conceivable to reduce the wavelength or increase the aperture ratio in order to reduce the spot diameter.

  As a method for further densification in the future, it is considered to use a minute spot using near-field light (evanescent light). As a method for realizing this, a method using a solid immersion lens (SIL) and a minute aperture are used. There is a method to use.

  The one using SIL is considered to be the same as that using a larger aperture ratio of the objective lens. As an application of SIL to optical recording, G. Patent Document 1 proposed by Kino et al., In which the incident light is incident perpendicular to the spherical surface of the solid immersion lens and converges to the center of the plane on the exit side. In this method, when the refractive index of the SIL is n, the minimum beam diameter can be reduced to 1 / n of the diffraction limit beam diameter. By bringing the recording medium close to the lens, the minute beam propagates in the near-field light, and the medium can be irradiated with the light of the minute spot.

When light is irradiated to a small opening, near-field light is generated in the vicinity of the opening. Attempts have also been made to record small pits using the near-field light (Patent Document 2, etc.). By using near-field light, it is possible to form a spot below the convergence limit of the light spot, and a small spot corresponding to a recording density of 100 Gbit / in ² or more is formed on the magneto-optical recording medium or the phase change recording medium. There is also a report that it was formed.

  When these methods are used, the tolerance for the tilt of the optical recording medium is reduced due to the influence of aberration, etc., but the distance between the optical head and the optical recording medium needs to be reduced. If the distance becomes large or the distance control is insufficient, good recording cannot be performed. As a method for controlling the distance between the optical head and the optical recording medium, there are a method using a piezoelectric element and a method for detecting a tunnel current.

Further, as described in Patent Documents 3 and 4, for example, a method is known in which a flexible optical disk is rotated on a stabilizing plate having a flat surface to stabilize surface runout in the optical disk.
Japanese Patent No. 2553275 JP-A-7-191046 JP-A-7-105657 Japanese Patent Laid-Open No. 10-308059

  However, even if the conventional method of controlling the distance between the optical head and the optical recording medium using the vibration of the piezoelectric element is applied to a system using a conventional optical recording medium that performs high-speed rotation such as optical recording, the distance can be reduced. There is a problem of insufficient control.

  It is an object of the present invention to provide an information recording apparatus that performs recording using near-field light on an information recording medium at a low cost without greatly changing the configuration of this type of conventional apparatus. The purpose is to do.

In order to achieve the above object, the invention described in claim 1 includes a light generating means for recording information by making near-field light incident on a flexible optical recording medium, and the optical recording medium. And a light detecting means for reading information from near-field light that has passed through the optical recording medium, disposed on the opposite side of the light generating means and on the opposite side of the surface of the optical recording medium on which information is recorded. A rotation driving means for rotating the optical recording medium; and a light generating means which is provided at a position facing the optical recording medium and stabilizes the surface shake during rotation of the optical recording medium by a pressure difference of an air flow. And a distance stabilizing means for stabilizing the distance between the optical recording medium and the distance stabilizing means opposite to the surface on which the information is recorded in the optical recording medium. This structure is Thus, in the information recording apparatus using near-field light, the distance stabilizing means stabilizes the distance between the light generating means and the optical recording medium, and the distance stabilizing means is a surface on which information is recorded. Since it is provided on the opposite side, even if the distance stabilizing means and the optical recording medium come into contact, the recording surface does not damage the recording surface, so the effect of the scratch on errors is reduced and stable. As a result, good recording is performed.

According to a second aspect of the present invention, in the information recording apparatus according to the first aspect, the distance stabilizing means is provided with a light detecting means .

According to a third aspect of the present invention, in the information recording apparatus according to the first or second aspect, the light detection means detects the light transmitted from the optical recording medium to detect light for reading information. It is characterized by that.

According to a fourth aspect of the present invention, in the information recording apparatus according to the first or second aspect , the distance stabilizing means comprises a projecting member that projects in the direction of the optical recording medium .

The invention according to claim 5, in the information recording apparatus according to claim 1 Symbol placement, as light generating means for generating near-field light, characterized by using a device having an opening formed by processing the Si or SiO2 .

According to the present invention, an information recording apparatus using a near-field light, the distance comprises a stabilizing means can stabilize the distance between the light generating means and the optical recording medium, also the distance stabilizing means information Since it is provided on the side opposite to the recorded surface, even if the distance stabilizing means and the optical recording medium come into contact, the contact surface will not damage the recording surface. Thus, good recording can be performed stably.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an optical information recording / reproducing apparatus as a reference example for explaining an embodiment of the present invention. 1 is an optical recording medium as a flexible information recording medium, and 2 is an optical recording medium. A disk drive unit 3 serving as a rotation drive unit such as a spindle motor that rotates by setting the recording medium 1 on a chucking unit provided on the spindle shaft 2a, and 3 is a recording unit that writes information to the optical recording medium 1. An optical head as a light generating means provided with 4, a light detecting element as a light detecting means provided with a reproducing means for reading information written on the optical recording medium 1, and 5 via the optical recording medium 1 The distance between the optical head 3 and the optical recording medium 1 is stabilized by stabilizing the surface shake of the optical recording medium 1 during rotation by the pressure difference of the air flow based on Bernoulli's law. You The distance stabilizing member as a stabilizing means for.

  6 is a controller that controls the entire apparatus, 7 is an operation drive control of each part, and a movement drive of a positioning mechanism that moves the optical head 3, the light detection element 4, and the distance stabilizing member 5 in the radial direction of the optical recording medium 1. A servo control unit 8 for controlling the above and the like, and a signal processing unit 8 for processing a recording / reproducing signal.

  The reference example is a configuration example in which the optical head 3 is provided in the distance stabilizing member 5 and both functions are provided in one member.

  FIG. 2 is a schematic configuration diagram of an optical information recording / reproducing apparatus for explaining an embodiment of the present invention, and members corresponding to those described in FIG. However, in the present embodiment, a configuration example is shown in which the light detection element 4 is provided in the distance stabilizing member 5 and both functions are provided in one member.

  A specific example of the basic configuration of the optical recording medium 1 of the present embodiment will be described.

  A thin sheet of about 0.1 mm was used as the substrate 11 of the optical recording medium 1 having flexibility. For example, an optical recording medium 1 is formed by transferring a groove having a stamper pitch of 0.6 μm and a width of 0.3 μm by thermal transfer onto a sheet of polyethylene terephthalate having a thickness of 80 μm, and then forming a recording layer 12 by sputtering. It was. In addition, the optical recording medium of the present invention can also be used by forming a transparent protective film having a thickness of 5 μm by spin coating a UV resin on a sheet as a substrate and curing it with ultraviolet irradiation.

  FIG. 3 is a sectional view showing a part of the optical recording medium 1, and the spindle shaft shown in FIGS. 1 and 2 is arranged so that the recording layer 12 formed on the flexible substrate 11 faces the optical head 3. 2a is set in the chucking portion provided in 2a.

  As the recording layer 12, each element of R, M, O (where R represents one or more elements selected from Y, Bi, In and lanthanum series elements, and M represents Al, Cr, Mn, Sc, In, Ru) , Rh, Co, Fe, Cu, Ni, Zn, Li, Si, Ge, Zr, Ti, Hf, Sn, Pb, Mo, V, and N, O represents oxygen. X, Y, O elements (wherein X represents one or more elements selected from Mg, Fe, Zn, Mn, Ni, Li, Y represents Al, Fe, Cr, Ti, A material composed of one or more elements selected from Mn, Ni, Co, Cu, and V (O represents oxygen), a material composed of carbon or a carbon compound, an oxide of Te, Sb, Mo, Ge, or the like. be able to.

  Further, as the optical recording medium 1, it is also possible to use an optical recording medium having a configuration in which a protective layer 13 is provided on a recording layer 12 as shown in FIG. Examples of the protective layer include oxides such as SiO2, SiN, and SiC, nitrides, and carbides.

  As a method for recording information on the optical recording medium 1, the signal processing unit 8 generates a digital signal suitable for recording on the recording layer 12 of the optical recording medium 1 and irradiates light corresponding to the signal from the optical head 3. To do. In order to generate near-field light, in the present embodiment, a flat probe having a minute aperture, which will be described later, is installed on the light emitting side of the optical head 3. Good recording can be performed by installing a light source that generates light having a wavelength of 550 nm or less in the optical head 3 that generates near-field light.

  Also, information is reproduced by irradiating the recording layer 12 of the optical recording medium 1 with light generated from the optical head 3, detecting the transmitted light with the light detection element 4, and converting it into an information signal with the signal processing unit 8. I do.

  Next, an example of a step of forming a planar probe that is provided on the light emitting side of the optical head 3 and generates near-field light at a minute aperture will be described with reference to FIGS.

  First, as shown in FIG. 5A, a chemically amplified resist is applied to a glass substrate 21, and a cylindrical resist pattern 25 is formed using an electron beam. Then, as shown in FIG. 5B, the cylindrical resist pattern 25 is used as a mask, and dry etching is performed to form a protrusion 24 by conic etching so that the cross-sectional shape becomes a trapezoid. Further, as shown in FIG. 5C, a metal film 22 is formed as a light shielding portion while the resist pattern 25 is left. Finally, as shown in FIG. 5D, the planar probe 10 having the opening 23 is formed by removing the resist pattern 25 by wet etching.

  Thus, by using the method of forming the planar probe 10, the size of the diameter of the opening 10a in the planar probe 10 can be accurately controlled, and dry etching is performed in a conical shape in FIG. When performing, since the shape of the cone can be easily changed by changing the configuration of the etching gas, etc., various highly efficient planar probes can be formed.

  Further, by processing using Si as a substrate, a near-field light generating element can be easily produced, and pyramidal minute openings 10a can be formed by anisotropic etching of Si with an aqueous potassium hydroxide solution. Can be formed.

  FIG. 6 is an explanatory diagram of the operation of recording / reproducing by controlling the distance between the optical recording medium and the optical head in the optical information recording / reproducing apparatus of the present embodiment. The optical recording medium 1 having the property is rotated between the optical head 3 and the distance stabilizing member 5 for controlling the distance. The rotating optical recording medium 1 itself is small but rigid, and when it rotates, it has a force to become straight due to the action of centrifugal force. Therefore, the optical recording medium 1 is straightened by bringing the distance stabilizing member 5 closer to the optical recording medium 1, generating a repulsive force due to the pressure difference of the air flow based on Bernoulli's law, and applying it to the optical recording medium 1. Due to the balance between the force to become the repulsive force and the repulsive force from the distance stabilizing member 5, a large surface shake (a shake in the disc rotation axis direction) can be reduced, and the optical recording medium 1 can be rotated stably. .

On the film surface side of the optical recording medium 1, an optical head 3 provided with a planar probe 10 is installed, and the planar probe 10 generates near-field light. The distance stabilizing member 5 and the optical head 3 are installed so that the distance between them is constant. By rotating the distance stabilizing member 5 close to the optical recording medium 1 and stably rotating, the optical head 3 and the optical recording medium 1 The distance is kept constant. As described above, the optical head 3 and the distance stabilizing member 5 are moved in the radial direction of the optical recording medium 1 while keeping the distance between the optical recording medium 1 and the optical head 3 constant. Recording can be performed on the medium 1 using near-field light. At the time of recording, an electric signal corresponding to the information signal subjected to signal processing is input to the laser diode 9, and the near-field light is generated in the planar probe 10 by driving the laser diode 9 to emit light. Record with.

  Further, at the time of reproduction, information is reproduced through the signal processing unit 8 by irradiating light of a certain intensity from the optical head 3 and detecting the light transmitted through the recording layer 12 of the optical recording medium 1 by the light detecting element 4. . In the present embodiment, the distance stabilizing member 5 is not placed opposite to the recording layer 12 of the optical recording medium 1. For example, in the configuration example shown in FIG. 6, a columnar distance stabilizing means 5 having a transparent arcuate surface facing the optical recording medium 1 is used, and the distance stabilizing member 5 incorporates the light detection element 4. It also has a recording signal detection function.

  FIG. 7 shows an enlarged view of the main part of FIG. 6, but the upstream of the disk rotation direction in the portion A where the surface runout due to the action of air pressure generated based on Bernoulli's law by the distance stabilizing member 5 in the optical recording medium 1 is stabilized Regions (space portions where the distance stabilizing member 5 is not provided) B and C in which the action of air pressure is not generated are provided on the side and the downstream side, and “ The presence of a portion that becomes “escape” reduces the repulsive force in the optical recording medium 1 in the portion A where the surface runout is stabilized. By doing in this way, the effect of the stabilization force by an aerodynamic force will increase. Light is irradiated from the laser diode 9 to the opening 10a of the planar probe 10 which is a near-field light generating portion, and the recording layer 12 of the optical recording medium 1 is irradiated with the near-field light generated from the opening 10a of the planar probe 10. Recording / playback.

  As described above, the light applied to the optical recording medium 1 is transmitted, detected by the light detecting element 4 provided in the distance stabilizing member 5, and information is reproduced through the signal processing unit 8. As shown in FIG. 7, the distance stabilizing member 5 is installed not on the recording layer 12 side but on the substrate 11 side in the optical recording medium 1.

  In the above-described embodiment, an example in which the planar probe 10 having the opening 10a formed to generate near-field light has been described. However, a solid immersion lens (SIL) is installed on the light emitting side of the optical head 3. Thus, near-field light may be generated.

  Further, depending on the specifications of the apparatus, an optical head 3 which is a light generating means for generating near-field light and a light detection unit having the function of the light detection element 4 may be installed in the distance stabilizing member 5. Conceivable.

  In the above embodiment, the optical information recording / reproducing apparatus has been described as an example. However, a flexible optical recording medium such as an optical information recording single-function apparatus or an optical information reproduction single-function apparatus is used. The same effect can be obtained by applying to the apparatus.

The present invention is applied to an optical information recording / reproducing apparatus that performs recording and / or reproduction using an optical information medium having flexibility .

1 is a schematic configuration diagram of an optical information recording / reproducing apparatus as a reference example for explaining an embodiment of the present invention. 1 is a schematic configuration diagram of an optical information recording / reproducing apparatus according to an embodiment of the present invention. Sectional drawing which shows an example of a structure of the optical recording medium applicable to this embodiment Sectional drawing which shows an example of a structure of the optical recording medium applicable to this embodiment Explanatory drawing which shows an example of the formation process of the planar probe of the optical head which generate | occur | produces the near field light in this embodiment Explanatory drawing of operation | movement of the optical information recording / reproducing apparatus in this embodiment. FIG. 6 is an enlarged view of a main part of the optical information recording / reproducing apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical recording medium 2 Disk drive part 3 Optical head 4 Photodetecting element 5 Distance stabilization member 6 Controller 7 Servo control part 8 Signal processing part 9 Laser diode 10 Planar probe 10a Opening 11 Substrate 12 Recording layer 13 Protective layer 21 Glass substrate 22 Metal film 24 Protrusion 25 Resist pattern

Claims (5)

Light generating means for recording information by making near-field light incident on a flexible optical recording medium, and the optical recording medium opposite to the light generating means and the optical recording medium A light detecting means for reading information from near-field light passing through the optical recording medium; a rotation driving means for rotating the optical recording medium; and the optical recording. Distance stabilization provided at a position facing the medium to stabilize the surface shake during rotation of the optical recording medium by the pressure difference of the air flow and to stabilize the distance between the light generating means and the optical recording medium. An information recording apparatus comprising:
An information recording apparatus characterized in that the distance stabilizing means is provided on the side opposite to the surface on which information is recorded in the optical recording medium.
The information recording apparatus according to claim 1 , wherein the light detecting means is provided in the distance stabilizing means . 3. The information recording apparatus according to claim 1 , wherein the light detection means is configured to detect light transmitted from the optical recording medium for detecting light for reading information. 3. The information recording apparatus according to claim 1, wherein the distance stabilizing means is constituted by a projecting member projecting in the direction of the optical recording medium . The near-field as a light generating means for generating light, according to claim 1 Symbol placement of the information recording apparatus characterized by using a device having an opening formed by processing the Si or SiO2.

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