JP2006031925A - Data storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data storage device wherein a defect of a conventional technique is solved and multi-dimensional and multi-leveled recording and storage are realized. <P>SOLUTION: Multiple recording layers are provided and data recording locations whose characteristics can be changed are provided on the respective multiple recording layers to attain the multi-dimensional and multi-leveled recording and storage. A single laser beam can be used and it is not needed to perform re-focusing between recording layers like a conventional data storage device. Data recording density and a data transfer rate are increased. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention generally relates to data storage devices. In particular, the present invention provides a laser beam source to provide a multi-level data storage structure that allows data storage in multiple dimensions to achieve high density and high data transfer rates on optical recording media. It relates to data storage devices that utilize different physical properties.

The optical data storage density is typically determined by the diameter of the light spot formed on the recording surface by laser irradiation. When the diameter of the light spot is d, it is expressed by the following formula.
d = λ / (2NA)
Here, λ is the wavelength of the laser, and NA (numerical aperture) is the numerical aperture. Smaller and smallest spot diameters result in high density data recording and storage. Therefore, in order to increase the recording density of the optical recording medium, the wavelength of the laser is shortened and the numerical aperture of the objective lens is increased. However, there is a drawback in shortening the laser wavelength and increasing the numerical aperture of the objective lens in order to achieve a high recording density. The coma produced by an inclined optical disk increases in magnitude in proportion to the cube of the numerical aperture. Therefore, using a large numerical aperture reduces the margin for the angular tilt of the optical disk. If the optical disc is tilted slightly, the laser will form a blurred spot on it, and a high recording density cannot be achieved.

  A well-known Blu-ray disc (registered trademark of Sony) has a recording density not lower than 23 GB and a data transfer rate of about 36 MBps. However, the optical system of the Blu-ray Disc uses a laser with a wavelength of 405 nm and an objective lens with a numerical aperture of 0.85. As a result, the Blu-ray disc requires a thin light transmission layer of about 0.1 mm to achieve a sufficient tilt margin. Unfortunately, such a thin light transmissive layer cannot be produced by conventional injection molding machines. Further, the strictness that the variation in thickness is within the tolerance of 0.2 μm results in a considerably high manufacturing cost as compared with the conventional optical disc. In addition, by using an objective lens with a high numerical aperture, the working distance is about 0.3 mm and the risk of collision between the optical disk and the objective lens is increased.

  In the prior art, it is known to provide a plurality of recording layers in order to achieve a high recording density. For example, it has been proposed that a double-layer optical recording medium can double the recording density by recording on two recording layers from the same side of the disc. However, providing a double layer to give the first layer a large transmittance is a technical challenge, and one material, such as a material with a phase change, will cause the laser to increase as its thickness increases. This is because it is not transparent.

PCT Publication WI-A2-0206620 (Arieri) discloses a method for solving the problem in the readout process, i.e., each layer optically interfering with other layers. Arrieli's invention describes an optical data storage device comprising a plurality of recording layers and a focusing system for focusing the laser on the intended recording layer for reading therefrom. However, Arieri's invention requires a refocusing of the laser for different recording layers, resulting in a slow rate for data retrieval. Furthermore, the recording density of each recording layer depends on the accuracy of the focusing system.

U.S. Pat. No. 5,838,653 (Mr. Fan) discloses an optical information storage system that includes a plurality of information storage layers. Each storage layer or part thereof specifies the wavelength and the polarization. Information can be read out only from a special storage layer by using a laser beam corresponding to them with a specific wavelength and a specific polarization. However, Fan's invention requires a spectrum of lasers that can meet the required wavelength and polarization range. Using a modulator to change the wavelength and polarization of a single laser is complex and slows the rate of data retrieval.

  Thus, there is clearly a need for an improved data storage system that achieves high recording density and high data transfer rate.

  A data storage device (apparatus) described later includes a substrate and a recording layer, and the recording layer includes a phase-change layer and a magneto-optical layer formed on the substrate. Have. This data storage device utilizes two physical properties: the amplitude of the laser reflected from it and the polarization level. A laser directed to the data storage device penetrates the substrate or cover and heats the recording layer. By adjusting the laser output, the phase change layer is switched between a crystallized state and an amorphous (non-crystalline) state. A phase change layer in the fully amorphous state exhibits a relative reflectance of 0%, whereas a phase change layer in the fully crystallized state exhibits a reflectance of 100%. By distinguishing and varying the laser power, different possible reflectance levels can be provided. Therefore, multi-level recording can be realized in the phase change recording layer using different reflectance levels.

  When the laser is directed onto the recording layer, the magneto-optic layer is heated simultaneously. When the magneto-optic layer temperature reaches the Curie temperature or compensation temperature of the layer, a bias magnetic field is applied to change the polarization level in the magneto-optic layer. The polarization of the reflected or transmitted laser or light beam can be detected through the effect of the magneto-optic layer. Accordingly, the reflectivity and polarization level of the reflected laser from the data storage device are combined to provide a medium for recording and storage having multiple dimensions and multiple levels.

In its first aspect, the present invention is a data storage device comprising:
A first recording layer having a first surface and a second surface opposite to the outer side of the first surface, the first recording layer having a first plurality of data storage locations, wherein the first plurality A first recording layer such that each of the data storage locations has a first physical property that is variable through at least two states for indicating a first data value;
A second recording layer stacked adjacent to a second surface of the first recording layer, the second recording layer having a second plurality of data storage locations, wherein the second plurality of data storages A second recording layer wherein each of the locations has a second physical characteristic that can be varied through at least two states for indicating a second data value;
A plurality of data axes formed generally perpendicular to the second surface of the first recording layer, each of the plurality of data axes being associated with a corresponding one of the first plurality of data storage locations; A data axis extending through a corresponding one of the second plurality of data storage locations,
A processed beam having first and second beam characteristics is processed from a laser beam directed toward the first recording layer and the second recording layer along one of the plurality of data axes, the laser beam Is first processed with one of at least two states determining the first beam characteristic by a corresponding one of the first plurality of data storage locations, followed by a corresponding one of the second plurality of data storage locations. Processed with one of the at least two states that determine the second beam characteristic by the first and second beam characteristics of the processed beam, respectively, corresponding to one of the first plurality of data storage locations and A data storage device is provided that is adapted to indicate a corresponding first and second data value of a second plurality of data storage locations.

In its second aspect, the present invention is a data storage device comprising:
A first recording layer having a first surface and a second surface opposite to the outside of the first surface, the first recording layer being made of a first material and having a first plurality of data storage locations A first recording layer, wherein each of the first plurality of data storage locations has a first physical characteristic that is variable through at least two states for indicating a first data value When,
A second recording layer laminated adjacent to the second surface of the first recording layer, the second recording layer being made of a second material and having a second plurality of data storage locations; Each of the second plurality of data storage locations has a second physical characteristic that is variable through at least two states for indicating a second data value, and the first physical characteristic is A second recording layer that is different from the second physical characteristics;
The first physical property is reflectivity, the second physical property is optical polarization, and at least one of the at least two states of each of the first plurality of data storage locations is reflectivity thereof. One of the at least two states of each of the second plurality of data storage locations corresponds to its optical polarization level;
The first material is a phase change material changeable into at least two states having at least two crystallization levels, and the second material is magnetic changeable into at least two states having at least two polarization states. An optical material,
The data storage device further includes a plurality of data axes formed substantially perpendicular to the second surface of the first recording layer, and each of the plurality of data axes is included in the first plurality of data storage locations. And a data axis extending through a corresponding one of the second plurality of data storage locations; and
A processed beam having first and second beam characteristics is processed from a laser beam directed toward the first recording layer and the second recording layer along one of the plurality of data axes, the laser beam Is first processed with one of at least two states determining the first beam characteristic by a corresponding one of the first plurality of data storage locations, followed by a corresponding one of the second plurality of data storage locations. Processed with one of the at least two states that determine the second beam characteristic by the first and second beam characteristics of the processed beam, respectively, corresponding to one of the first plurality of data storage locations and A data storage device is provided that is adapted to indicate a corresponding first and second data value of a second plurality of data storage locations.

In its third aspect, the present invention is a data storage device,
A first recording layer having a first surface and a second surface opposite to the outside of the first surface, the first recording layer being made of a first material and having a first plurality of data storage locations A first recording layer, wherein each of the first plurality of data storage locations has a first physical characteristic that is variable through at least two states for indicating a first data value When,
A second recording layer laminated adjacent to the second surface of the first recording layer, the second recording layer being made of a second material and having a second plurality of data storage locations; Each of the second plurality of data storage locations has a second physical characteristic that is variable through at least two states for indicating a second data value, and the first physical characteristic is A second recording layer that is different from the second physical characteristics;
The first physical property is optical polarization, the second physical property is reflectivity, and one of at least two states of each of the first plurality of data storage locations is optical therewith. Corresponding to the polarization level, one of the at least two states of each of the second plurality of data storage locations corresponds to the reflectance level therein;
The first material is a magneto-optical material capable of changing to at least two states having at least two polarization states, and the second material is changeable to at least two states having at least two crystallization levels. Phase change material,
The data storage device further includes a plurality of data axes formed substantially perpendicular to the second surface of the first recording layer, and each of the plurality of data axes is included in the first plurality of data storage locations. And a data axis extending through a corresponding one of the second plurality of data storage locations; and
A processed beam having first and second beam characteristics is processed from a laser beam directed toward the first recording layer and the second recording layer along one of the plurality of data axes, the laser beam Is first processed with one of at least two states determining the first beam characteristic by a corresponding one of the first plurality of data storage locations, followed by a corresponding one of the second plurality of data storage locations. Processed with one of the at least two states that determine the second beam characteristic by the first and second beam characteristics of the processed beam, respectively, corresponding to one of the first plurality of data storage locations and A data storage device is provided that is adapted to indicate a corresponding first and second data value of a second plurality of data storage locations.

  Hereinafter, the present invention will be described with reference to embodiments of the accompanying drawings. FIG. 1 is a longitudinal sectional view of a data storage device in which a first recording layer and a second recording layer are formed on a substrate according to the first embodiment of the present invention, and FIG. 2 is a diagram of FIG. 1 according to the second embodiment of the present invention. FIG. 3 is a longitudinal sectional view of a data storage device in which a reflective layer is formed on the second recording layer in addition to the structure. FIG. 3 shows a first protective layer in addition to the structure of FIG. 2 according to the third embodiment of the present invention. FIG. 4 is a longitudinal sectional view of a data storage device in which a second protective layer is formed. FIG. 4 shows an interface layer between the first recording layer and the second recording layer in addition to the structure of FIG. 3 according to the fourth embodiment of the present invention. FIG. 5 is a longitudinal sectional view of a data storage device in which the substrate is formed. FIG. 5 shows data in which the substrate is replaced with a cover layer and the substrate is formed on the reflective layer in the structure of FIG. 3 according to the fifth embodiment of the present invention. FIG. 6 is a longitudinal sectional view of the storage device, according to the sixth embodiment of the present invention. Is a longitudinal sectional view of a data storage device substrate is changed is and substrate placed in the cover layer is formed on the reflective layer in the structure of FIG.

  Hereinafter, a data storage device for solving the above-described drawbacks of the prior art will be described. FIG. 1 shows a data storage device 20 according to a first embodiment of the invention in longitudinal section. As shown in FIG. 1, the data storage device 20 includes a substrate 22 and a storage layer 24 stacked adjacent to the substrate 22. Substrate 22 and storage layer 24 are sized and dimensioned to provide a data storage device 20, preferably in the form of a disc.

  The storage layer 24 includes a first recording layer 26 and a second recording layer 28. The first recording layer 26 has a first surface 30a and a second surface 30b facing the outside of the first surface 30a. The second recording layer 28 is laminated adjacent to the second surface 30 b of the first recording layer 26 attached to the substrate 22, and is on the side opposite to the first surface 30 a of the first recording layer 26.

  The substrate 22 structurally supports the first recording layer 26 and the second recording layer 28. The substrate 22 is preferably made from one of polycarbonate, polymethylmethacrylate (PMMA), amorphous polyolefin, ceramic and glass. The thickness of the substrate 22 is preferably in the range of 0.1 mm to 1.2 mm, and the diameter is, for example, about 120 mm.

The first recording layer 26 includes a first plurality of data storage locations 32a, and the second recording layer 28 includes a second plurality of data storage locations 32b. The first recording layer 26 is made of a first material, and each of the first plurality of data storage locations 32a has a first physical characteristic that is variable through at least two states for indicating a first data value. Have. The second recording layer 28 is comprised of a second material, and each of the second plurality of data storage locations 32b has a second physical characteristic that can be varied through at least two states for indicating a second data value. Have.

  The first material and the second material are preferably different so that the first physical property is distinct from the second physical property. Alternatively, the first material and the second material may be the same. It is sufficient that at least one of the first material and the second material can be processed, and the first physical property and the second physical property can be distinguished. Instead, the first physical characteristics may be different from the second physical characteristics by changing the manufacturing process of at least one of the first recording layer 26 and the second recording layer 28.

  The data storage device 20 further includes a data axis 46 formed generally perpendicular to the second surface 30 b of the first recording layer 26. Each data axis 46 extends correspondingly through one of the first plurality of data storage locations 32a or one of the second plurality of data storage locations 32b. A laser beam 48 can be directed along one of the data axes 46 to the first recording layer 26 and the second recording layer 28, from which a processed beam 50 is obtained. The laser beam 48 is preferably directed through a substrate 20 that can transmit light. The processed beam has a first beam characteristic and a second beam characteristic.

  The laser beam 48 is aligned with each of the first recording layer 26 and the second recording layer 28 to form a mark on each of the first recording layer 26 and the second recording layer 28, and on each of them. Each of the marks corresponds to one of the first plurality of data storage locations 32a and one of the second plurality of data storage locations 32b and represents the data.

  When the laser beam 48 is directed along one of the data axes 46 toward the first surface 30a of the first recording layer 26, the laser beam 48 initially corresponds to the first plurality of data storage locations 32a. One of those at least two states determines a first beam characteristic and subsequently processed by a corresponding one of the second plurality of data storage locations 32b, at least of those One of the two states is adapted to determine the second beam characteristic. The determined first beam characteristic and second beam characteristic of the processed beam 50 correspond to a corresponding one of the first plurality of data storage locations 32a and a corresponding one of the second plurality of data storage locations 32b, respectively. One first data value and a second data value are indicated.

  The first physical property is preferably reflectance and the second physical property is preferably optical polarization. However, the first and second physical characteristics in the data storage device of the present invention are not limited to reflectance and optical polarization, respectively. One of at least two states of each of the first plurality of data storage locations 32a corresponds to its reflectance level, and one of at least two states of each of the second plurality of data storage locations 32b is its optical polarization. It only needs to correspond to the level.

  The first material can suitably be made from one or more mixtures of, for example, copper or brass compound elements. The one or more elements can preferably be selected from Te, Ge, Sb, Bi, Pd, Sn, As, Ag, In, Se, S, Si, P and organic recording materials. The first material allows the first recording layer 26 to function as a phase change material, with at least two of these states being at least two crystallization levels. The first physical property can vary between a generally crystallized state and a generally amorphous (non-crystalline) state, with at least two crystallization levels extending between them to form a grade. Therefore, changing a part of the first recording layer 26 between a substantially crystallized state and a substantially amorphous state changes at least one of the reflectance and transmittance of the part of the first recording layer 26. become.

  The first physical property of the first material can be varied by a laser beam 48 having a magnitude corresponding to at least two crystallization levels.

  A generally low reflectivity is achieved when the corresponding one of the first plurality of data storage locations 32a is in a completely amorphous state. Increasing the corresponding one crystallization of the first plurality of data storage locations 32a results in an increase in its reflectivity. A generally high reflectivity is achieved when the corresponding one of the first plurality of data storage locations 32a is fully crystallized.

  The second material is preferably one or more of Fe, Co, Ni and one of Tb, Cr, Gd, Mn, Pt, Pd, Al, Au, Ag, Cu, Mg. Or made from a mixture with multiple. The second material allows the second recording layer 28 to function as a magneto-optical material, and at least two of those states become at least two polarization states. The second physical property of the second material can vary between two optical polarization levels, and at least two polarization states stretch between them to form a grade. Therefore, changing the second physical property of the portion of the second recording layer 28 between the two polarization levels changes at least two polarization states of the portion of the second recording layer 28.

  The second recording layer 28 is preferably generally magnetically anisotropy, and the second material has a high cohesive force to allow small recorded data bits to be formed, which As a result, the amount of the second plurality of data storage locations 32b on the second recording layer 28 can be increased.

  The second physical properties of the second material can be varied such that the heat generated by the laser beam 48 on the portion of the second material can achieve their Curie temperature or compensation temperature. The magnetic direction of the magnetic field applied to can also be changed. The magnetic field is generated by one of a permanent magnet or an electromagnet.

  Each of the first recording layer 26 and the second recording layer 28 includes vacuum processing, electron beam vacuum processing, ion plating, chemical vapor processing, plasma CVD, laser processing, spinning coating, molecular beam epitaxy, Formed by processing a corresponding one of the first material and the second material by one of the sputtering.

  Preferably, each of the first recording layer 26 and the second recording layer 28 is dope by sputtering a mixture further containing argon and containing at least one of nitrogen and oxygen. Can do.

  The range of magnitude and the level range are preferably set in advance so that the data storage device 20 is easy to use. The magnitude range cooperates with the first plurality of values including the first data value. The level range cooperates with a second plurality of values including a second data value.

  The first beam characteristic and the second beam characteristic of the processed beam 50 have respective magnitudes and optical polarization levels. Accordingly, by detecting the magnitude and optical polarization level of the processed beam 50 and identifying one of the corresponding magnitude ranges and one of the optical polarization level ranges, the corresponding one of the plurality of first values. And the corresponding one of the plurality of second values.

  Accordingly, the first data value and the second data value are stored in one of the plurality of data storage locations 32a and 32b on the first recording layer 26 and the second recording layer 28, respectively. The reflected beam 50 is reflected therefrom to obtain a corresponding one of a plurality of first values and a corresponding one of a plurality of second values.

  One of the first plurality of data storage locations 32a and one of the second plurality of data storage locations 32b combine (combined forms) at least two numerical bits of data along each of the data axes 46. ) As an accumulation.

  However, four identifiable states are achieved for the first physical property, eg, as four identifiable levels of reflectivity, or two identifiable states for the second physical property. It can also be achieved, for example, as two polarization levels. In this case, one of the first plurality of data storage locations 32a and one of the second plurality of data storage locations 32b has eight combined recording levels along each of the data axes 46, with the data therein As accumulation, it can be converted into 3 binary bits and accumulated.

  The first recording layer 26 and the second recording layer 28 supply a multilevel recording structure to the data storage device 20. The variable first physical characteristic of each of the first plurality of data storage locations 32a and the variable second physical characteristic of each of the second plurality of data storage locations 32b are the first recording layer 26. And the second recording layer 28 can be provided with a multidimensional data recording capability. Therefore, the data storage device 20 can functionally achieve a multidimensional and multilevel optical recording medium.

  In addition, one of an AND operator, an OR operator, a NAND operator, and a NOR operator can be applied to the obtained first data value and second data value to obtain further data therefrom. .

  FIG. 2 shows a data storage device 70 according to a second embodiment of the present invention, which comprises two main elements: a substrate 22, a first recording layer 26 and a second recording layer 28. And a storage layer 24 having Structural form and position between the first plurality of data storage locations 32a and the second plurality of data storage locations 32b corresponding to the substrate 22 and the storage layer 24, and the first recording layer 26 and the second recording layer 28 The description of the relationship is described in the description of the first embodiment shown in FIG.

  The data storage device 70 further includes a reflective layer 72 stacked adjacent to the surface of the second recording layer 28 that is away from the first recording layer 26. The reflection layer 72 is for dissipating excessive accumulation of heat generated when the laser beam 48 is applied to the second recording layer 28 during the process of reading and writing data. The reflective layer 72 is made of at least one of Au, Al, Ag, Ti, Cr, Cu, Pd, W, and Pt.

  FIG. 3 shows a data storage device 80 according to a third embodiment of the present invention, which comprises three main elements: a substrate 22, a first recording layer 26 and a second recording layer 28. And the reflective layer 72. Structure between the substrate 22, the storage layer 24, the reflective layer 72, and the first plurality of data storage locations 32a and the second plurality of data storage locations 32b corresponding to the first recording layer 26 and the second recording layer 28 The description of the specific form and the positional relationship is described in the description of the second embodiment shown in FIG.

  The data storage device 80 further includes a first protective layer 82 and a second protective layer 84. The first protective layer 82 is laminated adjacent to the first surface 30a of the first recording layer 26, while the second protective layer 84 is laminated adjacent to the first recording layer 28 and the reflective layer 72 and the second layer. It is interposed between the recording layer 28. The first recording layer 26 and the second recording layer 28 are disposed and interposed between the first protective layer 82 and the second protective layer 84. Each of the first protective layer 82 and the second protective layer 84 is made of at least one of a metal oxide, nitride, copper or brass compound element, fluoride, or carbide.

Alternatively, the first protective layer 82 each of the second protective layer _{84, SiO 2, SiO, Al} 2 O 3, GeO 2, In 2 O 3, TeO 2, TiO 2, Ta 2 O 5, MoO 3 , WO ₃ , Si ₃ N ₄ , AlN, BN, TiN, ZnS, CdS, CdSe, ZnTe, AgF, PdF ₂ , SiC, and mixtures thereof may be used. The first protective layer 82 and the second protective layer 84 are for preventing the first recording layer 26 and the second recording layer 28 from corroding.

  FIG. 4 shows a data storage device 90 according to a fourth embodiment of the present invention, which comprises five main elements: a substrate 22, a first recording layer 26 and a second recording layer 28. The storage layer 24, the reflective layer 72, the first protective layer 82, and the second protective layer 84. The substrate 22, the storage layer 24, the reflective layer 72, the first protective layer 82, the second protective layer 84, and the first plurality of data storage locations 32a and second corresponding to the first recording layer 26 and the second recording layer 28. The description of the structural form and positional relationship with the plurality of data storage locations 32b is described in the description of the third embodiment shown in FIG.

  The data storage device 90 further includes an interface layer 92 that is stacked between the first recording layer 26 and the second recording layer 28. Preferably, interface layer 92 is optically transparent to laser beam 48 directed therethrough. The interface layer 92 is preferably made of one of an insulating material and a metallic material, one of a magnetic material and a non-magnetic material. The interface layer 92 adjusts the temperature of the second recording layer so that the heat generated by the laser beam 48 is at a minimum temperature when the laser beam 48 is applied to the second recording layer during the data recording process. It is for improving the control.

  FIG. 5 shows a data storage device 100 according to a fifth embodiment of the present invention, which comprises five main elements: a substrate 22, a first recording layer 26 and a second recording layer 28. The storage layer 24, the reflective layer 72, the first protective layer 82, and the second protective layer 84. The storage layer 24, the reflective layer 72, the first protective layer 82, the second protective layer 84, the first plurality of data storage locations 32a corresponding to the first recording layer 26 and the second recording layer 28, and the second plurality of data. The description of the structural form and positional relationship with the data storage location 32b is described in the description of the third embodiment shown in FIG.

  In the fifth embodiment, the substrate 22 shown in the third embodiment of the present invention is replaced with a cover layer 102, and the cover layer 102 is laminated adjacent to the first surface 30 a of the first recording layer 26. Yes. In this embodiment, the substrate 22 is spatially changed and arranged on the surface of the reflective layer 72 laminated outside the second protective layer 84. As a result, the reflective layer 72 is laminated between the second protective layer 84 and the substrate 22.

  The data storage device 100 in the fifth embodiment is suitable when a short wavelength laser light source, for example, a 405 nm violet blue laser diode is used to generate the laser beam 48. In the fifth embodiment, the laser beam is transmitted through the cover layer 102 and into the data storage device 100. Cover layer 102 is preferably made from at least one of polycarbonate, cellulose triacetate, polydicyclopentadiene, methyl methacrylate, methyl propyl acrylate, such as solvent casting, polymerization casting, die coating, etc. Formed using one method. In addition, the cover layer can be further formed using one method such as spin coating following UV processing or lamination processing applying a pressure sensitive adhesive layer. It is preferable that the thickness of the cover layer 102 does not exceed 3 μm.

  FIG. 6 shows a data storage device 120 according to a sixth embodiment of the present invention, the data storage device 100 comprising six main elements: a substrate 22, a first recording layer 26 and a second recording layer 28. The storage layer 24, the reflective layer 72, the first protective layer 82, the second protective layer 84, and the interface layer 92. The storage layer 24, the reflective layer 72, the interface layer 92, the first protective layer 82, the second protective layer 84, the first plurality of data storage locations 32 a corresponding to the first recording layer 26 and the second recording layer 28, and the first The description of the structural form and positional relationship between the plurality of data storage locations 32b is described in the description of the fourth embodiment shown in FIG.

  In the sixth embodiment, the substrate 22 shown in the fourth embodiment of the present invention is replaced with a cover layer 112, and the cover layer 112 is laminated adjacent to the first surface 30a of the first recording layer 26. Yes. In this embodiment, the substrate 22 is spatially changed and arranged on the surface of the reflective layer 72 laminated outside the second protective layer 84. As a result, the reflective layer 72 is laminated between the second protective layer 84 and the substrate 22.

  The data storage device 120 in the sixth embodiment is similar to the data storage device 100 in the fifth embodiment in that a short wavelength laser light source, such as a 405 nm violet blue laser diode, is used to generate the laser beam 48. It is suitable for the case where it exists. In the sixth embodiment, the laser beam is transmitted through the cover layer 112 and into the data storage device 120. The cover layer 112 is preferably made from at least one of polycarbonate, cellulose triacetate, polydicyclopentadiene, methyl methacrylate, methyl propyl acrylate, and can be formed by one method such as solvent casting, polymerization casting, or die coating. Formed using. In addition, the cover layer can be further formed using one method such as spin coating following UV processing or lamination processing applying a pressure sensitive adhesive layer. It is preferable that the thickness of the cover layer 112 does not exceed 3 μm.

  The present invention has been presented and described in six embodiments for overcoming the aforementioned drawbacks of conventional data storage devices. Although the present invention has disclosed only six embodiments, it will be apparent to those skilled in the art that many variations and modifications can be made without departing from the scope and spirit of the invention.

1 is a longitudinal sectional view of an embodiment of a data storage device according to the present invention. FIG. 6 is a longitudinal sectional view of another embodiment of a data storage device according to the present invention. FIG. 6 is a longitudinal sectional view of another embodiment of a data storage device according to the present invention. FIG. 6 is a longitudinal sectional view of another embodiment of a data storage device according to the present invention. FIG. 6 is a longitudinal sectional view of another embodiment of a data storage device according to the present invention. FIG. 6 is a longitudinal sectional view of another embodiment of a data storage device according to the present invention.

Explanation of symbols

20, 70, 80, 90, 100, 120 Data storage device 22 Substrate 26 First recording layer 28 Second recording layer 30a, 30b Surface 32a, 32b Data storage location 46 Data axis 48, 50 Laser beam 72 Reflective layer 82, 84 Protective layer 92 Interface layer 102, 112 Cover layer

Claims (49)

A data storage device,
A first recording layer having a first surface and a second surface opposite to the outer side of the first surface, the first recording layer having a first plurality of data storage locations, wherein the first plurality A first recording layer such that each of the data storage locations has a first physical property that is variable through at least two states for indicating a first data value;
A second recording layer stacked adjacent to a second surface of the first recording layer, the second recording layer having a second plurality of data storage locations, wherein the second plurality of data storages A second recording layer wherein each of the locations has a second physical characteristic that can be varied through at least two states for indicating a second data value;
A plurality of data axes formed generally perpendicular to the second surface of the first recording layer, each of the plurality of data axes being associated with a corresponding one of the first plurality of data storage locations; A data axis extending through a corresponding one of the second plurality of data storage locations,
A processed beam having first and second beam characteristics is processed from a laser beam directed toward the first recording layer and the second recording layer along one of the plurality of data axes, the laser beam Is first processed with one of at least two states determining the first beam characteristic by a corresponding one of the first plurality of data storage locations, followed by a corresponding one of the second plurality of data storage locations. Processed with one of the at least two states that determine the second beam characteristic by the first and second beam characteristics of the processed beam, respectively, corresponding to one of the first plurality of data storage locations and A data storage device adapted to indicate a corresponding first and second data value of the second plurality of data storage locations. The first physical property is reflectivity, the second physical property is optical polarization, and at least one of the at least two states of each of the first plurality of data storage locations is reflectivity thereof. The data storage device of claim 1, wherein the data storage device corresponds to a level and one of the at least two states of each of the second plurality of data storage locations corresponds to an optical polarization level therein. The laser beam is first directed toward the first recording layer, and subsequently directed toward the second recording layer along one of the plurality of data axes, from which a processed beam is subsequently obtained. The data storage device according to claim 1 or 2, wherein the data storage device is adapted to be used. The first recording layer is made of a first material, the second recording layer is made of a second material, and the first material is either a different material from the second material or the same material. The data storage device according to claim 1. The first material is a phase change material changeable into at least two states having at least two crystallization levels, and the second material is magnetic changeable into at least two states having at least two polarization states. 5. A data storage device according to claim 4, wherein the data storage device is an optical material. The first physical property of the first material can vary between a generally crystallized state and a generally amorphous state, and is stretched and graded to have at least two crystallized states. Is supposed to form
By changing a part of the first material between a substantially crystallized state and a substantially amorphous state, at least one of the reflectance and the transmittance of the part of the first material can be changed. The data storage device according to claim 5. The first physical property of the first material is changeable by a laser beam having a size, the size of the laser beam corresponding to at least two crystallization levels. Data storage device. The second physical property of the second material is variable between two optical polarization levels, and is stretched between them to form a grade so as to have at least two polarization states. And
Claims wherein at least two polarization states of the portion of the second material are changed by changing a second physical property of the portion of the second material between two optical polarization levels. Item 8. The data storage device according to any one of Items 5 to 7. The second physical property of the second material is variable by the heat generated by the laser beam on the portion of the second material and the magnetic direction of the magnetic field applied thereto. The data storage device according to any one of 5 to 8. The data storage device of claim 9, wherein the magnetic field is generated by one of a permanent magnet and an electromagnet. The first material is one element selected from at least one of Te, Ge, Sb, Bi, Pd, Sn, As, Ag, In, Se, S, Si, P, and an organic recording material. 11. A data storage device according to any one of claims 4 to 10, which is made. The second material is made of at least one of Fe, Co, and Ni and at least one of Tb, Cr, Gd, Mn, Pt, Pd, Al, Au, Ag, Cu, and Mg. The data storage device according to any one of claims 4 to 11. Each of the first recording layer and the second recording layer is formed by one of vacuum processing, electron beam vacuum processing, ion plating, chemical vapor processing, plasma CVD, laser processing, spinning coating, molecular beam epitaxy, and sputtering. 13. A data storage device according to any one of claims 4 to 12, formed by processing a corresponding one of a first material and a second material. 14. The concentrated liquid treatment according to claim 4, wherein each of the first recording layer and the second recording layer is subjected to a concentrated liquid treatment by sputtering a mixture containing argon and containing at least one of nitrogen and oxygen. The data storage device described in 1. Furthermore, a substrate for structurally supporting the first recording layer and the second recording layer is included, the first recording layer is laminated adjacent to the substrate, and the first surface faces the substrate. The data storage device according to claim 1. The data storage device of claim 15, wherein the substrate is made from one of polycarbonate, polymethylmethacrylate, amorphous polyolefin, ceramic and glass. Furthermore, a substrate for structurally supporting the first recording layer and the second recording layer is included, the second recording layer is laminated adjacent to the substrate, and is spatially formed between the substrate and the first recording layer. Between them,
Furthermore, the cover layer is laminated adjacent to the first recording layer, and the first surface of the first recording layer faces the cover layer,
The substrate is made of one of polycarbonate, polymethyl methacrylate, amorphous polyolefin, ceramic and glass, and the cover layer is made of at least one of polycarbonate, cellulose triacetate, polydicyclopentadiene, methyl methacrylate, methylpropyl acrylate. 15. A data storage device according to claim 1, wherein the data storage device is made. And further comprising an interface layer stacked between the first recording layer and the second recording layer, the interface layer being optically transparent to a laser beam directed through it. Item 18. A data storage device according to any one of Items 1 to 17. 19. The data storage device of claim 18, wherein the interface layer is made of one of an insulating material and a metallic material that is one of a magnetic material and a non-magnetic material. The first recording layer further includes a first protective layer stacked adjacent to the first surface of the first recording layer, and a second protective layer stacked adjacent to the second recording layer. The layer and the second recording layer are between or stacked between the first protective layer and the second protective layer, and each of the first protective layer and the second protective layer is a metal oxide, nitride, copper or brass. 20. A data storage device according to claim 1, wherein the data storage device is made of at least one of the following compound elements, fluorides and carbides. Further, it includes a reflective layer laminated adjacent to the surface of the second protective layer and facing the outside of the second recording layer, and this reflective layer has a laser beam applied to the second recording layer. 21. The data storage device of claim 20, wherein the data storage device is adapted to dissipate excessive accumulation of heat sometimes generated by the laser beam. The first recording layer further includes a first insulating layer stacked adjacent to the first surface of the first recording layer, and a second insulating layer stacked adjacent to the second recording layer. layer and the second recording layer are or laminated is between the first insulating layer and the second insulating layer, each of the first insulating layer and the second insulating layer, SiO _2, SiO, Al ₂ O _{3, GeO 2, In 2 O 3,} TeO 2, TiO 2, Ta 2 O 5, MoO 3, WO 3, Si 3 N 4, AlN, BN, TiN, ZnS, CdS, CdSe, ZnTe, AgF, PdF 2, SiC 20. A data storage device according to any one of the preceding claims, made from at least one of: and a mixture thereof. Furthermore, a reflection layer is laminated so as to be adjacent to the surface of the second insulating layer and to face the outside of the second recording layer, and this reflection layer has a laser beam applied to the second recording layer. 23. A data storage device according to claim 22, adapted to dissipate the excessive accumulation of heat sometimes generated by the laser beam. Further, the reflective layer includes a reflective layer laminated adjacent to the surface of the second recording layer and facing the outside of the first recording layer, and a laser beam is applied to the second recording layer. 20. A data storage device according to any one of the preceding claims, adapted to dissipate the excessive accumulation of heat sometimes generated by the laser beam. 25. The data storage device according to claim 21, wherein the reflective layer is made of at least one of Au, Al, Ag, Ti, Cr, Cu, Pd, W, and Pt. 26. A data storage device according to claim 1, wherein the first recording layer and the second recording layer store at least two numeric bits of data. And a plurality of magnitude ranges that cooperate with a first plurality of predefined values and including a first data value;
A plurality of level ranges, the level range cooperating with a second plurality of predefined values and including a second data value, the first beam characteristic and the second beam characteristic of the processed beam Are the processed beam size and optical polarization level, respectively.
This detects the size and optical polarization level of the processed beam and identifies a plurality of corresponding magnitude ranges by identifying one of the magnitude ranges and one of the level ranges. One of the first values and one of the plurality of second values can be identified,
A first stored on the first recording layer and the second recording layer, respectively, at one of the plurality of data storage locations of each of the first recording layer and the second recording layer from which the processed beam is reflected. 27. A data storage according to claim 1, wherein the data value and the second data value are obtained from a corresponding one of a plurality of first values and a corresponding one of a plurality of second values. device. The data stored in the data storage device can be obtained by applying one of an AND operator, an OR operator, a NAND operator, and a NOR operator to the obtained first and second data values. The data storage device according to any one of claims 1 to 27. A data storage device,
A first recording layer having a first surface and a second surface opposite to the outside of the first surface, the first recording layer being made of a first material and having a first plurality of data storage locations A first recording layer, wherein each of the first plurality of data storage locations has a first physical characteristic that is variable through at least two states for indicating a first data value When,
A second recording layer laminated adjacent to the second surface of the first recording layer, the second recording layer being made of a second material and having a second plurality of data storage locations; Each of the second plurality of data storage locations has a second physical characteristic that is variable through at least two states for indicating a second data value, and the first physical characteristic is A second recording layer that is different from the second physical characteristics;
The first physical property is reflectivity, the second physical property is optical polarization, and at least one of the at least two states of each of the first plurality of data storage locations is reflectivity thereof. One of the at least two states of each of the second plurality of data storage locations corresponds to its optical polarization level;
The first material is a phase change material changeable into at least two states having at least two crystallization levels, and the second material is magnetic changeable into at least two states having at least two polarization states. An optical material,
The data storage device further includes a plurality of data axes formed substantially perpendicular to the second surface of the first recording layer, and each of the plurality of data axes is included in the first plurality of data storage locations. And a data axis extending through a corresponding one of the second plurality of data storage locations; and
A processed beam having first and second beam characteristics is processed from a laser beam directed toward the first recording layer and the second recording layer along one of the plurality of data axes, the laser beam Is first processed with one of at least two states determining the first beam characteristic by a corresponding one of the first plurality of data storage locations, followed by a corresponding one of the second plurality of data storage locations. Processed with one of the at least two states that determine the second beam characteristic by the first and second beam characteristics of the processed beam, respectively, corresponding to one of the first plurality of data storage locations and A data storage device adapted to indicate a corresponding first and second data value of the second plurality of data storage locations. The first physical property of the first material can vary between a generally crystallized state and a generally amorphous state, and is stretched and graded to have at least two crystallized states. And changing at least one of the reflectance and transmittance of the first material portion by changing a portion of the first material between a substantially crystallized state and a substantially amorphous state. Can be changed,
30. The method of claim 29, wherein the first physical property of the first material can be varied by a laser beam having a certain size, the size of the laser beam corresponding to at least two crystallization levels. Data storage device. The second physical property of the second material is variable between two optical polarization levels, and is stretched between them to form a grade so as to have at least two polarization states. And changing the second physical property of the portion of the second material between the two optical polarization levels allows the at least two polarization states of the portion of the second material to be changed. And
This allows the second physical property of the second material to be varied by the heat generated by the laser beam on the portion of the second material and the magnetic direction of the magnetic field applied thereto. The data storage device according to claim 29 or 30. 32. The data storage device of claim 31, wherein the magnetic field is generated by one of a permanent magnet and an electromagnet. The first material is one element selected from at least one of Te, Ge, Sb, Bi, Pd, Sn, As, Ag, In, Se, S, Si, P, and an organic recording material. Made,
The second material is made of at least one of Fe, Co, and Ni and at least one of Tb, Cr, Gd, Mn, Pt, Pd, Al, Au, Ag, Cu, and Mg. 33. A data storage device according to any one of claims 29 to 32. Each of the first recording layer and the second recording layer is formed by one of vacuum processing, electron beam vacuum processing, ion plating, chemical vapor processing, plasma CVD, laser processing, spinning coating, molecular beam epitaxy, and sputtering. 34. A data storage device according to any of claims 29 to 33, formed by processing a corresponding one of a first material and a second material. 35. The concentrated liquid treatment according to claim 29, wherein each of the first recording layer and the second recording layer is subjected to a concentrated liquid treatment by sputtering a mixture containing argon and containing at least one of nitrogen and oxygen. The data storage device described in 1. Furthermore, a substrate for structurally supporting the first recording layer and the second recording layer is included, the first recording layer is laminated adjacent to the substrate, and the first surface faces the substrate. 36. A data storage device according to any one of claims 29 to 35. The data storage device of claim 36, wherein the substrate is made from one of polycarbonate, polymethylmethacrylate, amorphous polyolefin, ceramic and glass. Further, the reflective layer includes a reflective layer laminated adjacent to the surface of the second recording layer and facing the outside of the first recording layer, and a laser beam is applied to the second recording layer. In some cases, excessive heat generated by the laser beam is dissipated, and the reflective layer is at least one of Au, Al, Ag, Ti, Cr, Cu, Pd, W, and Pt. 38. A data storage device according to any of claims 29 to 37, made from one. A first protective layer stacked adjacent to the first surface of the first recording layer, the first protective layer being stacked between the substrate and the first recording layer;
A second protective layer stacked adjacent to the second recording layer, wherein the first recording layer and the second recording layer are between or stacked between the first protective layer and the second protective layer. And
Further, it includes a reflective layer laminated adjacent to the surface of the second protective layer and facing the outside of the second recording layer, and this reflective layer has a laser beam applied to the second recording layer. Sometimes it dissipates the excessive accumulation of heat generated by the laser beam,
Each of the first and second protective layers is made of at least one of metal oxides, nitrides, copper or brass compound elements, fluorides, carbides, and the reflective layer comprises Au, The data storage device according to any one of claims 36 to 38, which is made of at least one of Al, Ag, Ti, Cr, Cu, Pd, W, and Pt. A first insulating layer stacked adjacent to the first surface of the first recording layer, the first insulating layer being stacked between the substrate and the first recording layer;
A second insulating layer stacked adjacent to the second recording layer, wherein the first recording layer and the second recording layer are between or stacked between the first insulating layer and the second insulating layer. And
Furthermore, a reflection layer is laminated so as to be adjacent to the surface of the second insulating layer and to face the outside of the second recording layer, and this reflection layer has a laser beam applied to the second recording layer. Sometimes it dissipates the excessive accumulation of heat generated by the laser beam,
Each of the first insulating layer and the second insulating layer is made of SiO ₂ , SiO, Al ₂ O ₃ , GeO ₂ , In ₂ O ₃ , TeO ₂ , TiO ₂ , Ta ₂ O ₅ , MoO ₃ , WO ₃ , Si _{3. N 4, AlN, BN, TiN} , ZnS, CdS, CdSe, ZnTe, AgF, PdF 2, SiC and data according to any one of claims 36 to 38 is made from at least one in a mixture thereof Storage device. And further comprising an interface layer stacked between the first recording layer and the second recording layer, the interface layer being optically transparent to a laser beam directed through it. Item 41. The data storage device according to any one of Items 29 to 40. 42. The data storage device of claim 41, wherein the interface layer is made of one of an insulating material and a metallic material that is one of a magnetic material and a non-magnetic material. A first insulating layer stacked adjacent to the first surface of the first recording layer, the first insulating layer being stacked between the substrate and the first recording layer;
A second insulating layer stacked adjacent to the second recording layer, wherein the first recording layer and the second recording layer are between or stacked between the first insulating layer and the second insulating layer. And
Furthermore, a reflection layer is laminated so as to be adjacent to the surface of the second insulating layer and to face the outside of the second recording layer, and this reflection layer has a laser beam applied to the second recording layer. Sometimes it dissipates the excessive accumulation of heat generated by the laser beam,
Furthermore, a cover layer is laminated adjacent to the first insulating layer, and a first insulating layer is laminated between the cover layer and the first recording layer,
Furthermore, a substrate for structurally supporting the first recording layer and the second recording layer is included, and the reflective layer is further laminated adjacent to the substrate and between the second insulating layer and the substrate. Are stacked
Each of the first insulating layer and the second insulating layer is made of SiO ₂ , SiO, Al ₂ O ₃ , GeO ₂ , In ₂ O ₃ , TeO ₂ , TiO ₂ , Ta ₂ O ₅ , MoO ₃ , WO ₃ , Si _3. N ₄ , AlN, BN, TiN, ZnS, CdS, CdSe, ZnTe, AgF, PdF ₂ , SiC, and mixtures thereof, and the reflective layer includes Au, Al, Ag, Made of at least one of Ti, Cr, Cu, Pd, W, Pt, and the substrate is made of one of polycarbonate, polymethyl methacrylate, amorphous polyolefin, ceramic and glass; The cover layer is at least one of polycarbonate, cellulose triacetate, polydicyclopentadiene, methyl methacrylate, and methylpropyl acrylate. Data storage device according to claim 36, wherein it is made from One. And a plurality of magnitude ranges that cooperate with a first plurality of predefined values and including a first data value;
A plurality of level ranges, the level range cooperating with a second plurality of predefined values and including a second data value, the first beam characteristic and the second beam characteristic of the processed beam Are the processed beam size and optical polarization level, respectively.
This detects the size and optical polarization level of the processed beam and identifies a plurality of corresponding magnitude ranges by identifying one of the magnitude ranges and one of the level ranges. One of the first values and one of the plurality of second values can be identified,
A first stored on the first recording layer and the second recording layer, respectively, at one of the plurality of data storage locations of each of the first recording layer and the second recording layer from which the processed beam is reflected. 44. A data accumulation according to any of claims 29 to 43, wherein the data value and the second data value are obtained from a corresponding one of a plurality of first values and a corresponding one of a plurality of second values. device. The data stored in the data storage device can be obtained by applying one of an AND operator, an OR operator, a NAND operator, and a NOR operator to the obtained first and second data values. 45. A data storage device according to any of claims 29 to 44. A data storage device,
A first recording layer having a first surface and a second surface opposite to the outside of the first surface, the first recording layer being made of a first material and having a first plurality of data storage locations A first recording layer, wherein each of the first plurality of data storage locations has a first physical characteristic that is variable through at least two states for indicating a first data value When,
A second recording layer laminated adjacent to the second surface of the first recording layer, the second recording layer being made of a second material and having a second plurality of data storage locations; Each of the second plurality of data storage locations has a second physical characteristic that is variable through at least two states for indicating a second data value, and the first physical characteristic is A second recording layer that is different from the second physical characteristics;
The first physical property is optical polarization, the second physical property is reflectivity, and one of at least two states of each of the first plurality of data storage locations is optical therewith. Corresponding to the polarization level, one of the at least two states of each of the second plurality of data storage locations corresponds to the reflectance level therein;
The first material is a magneto-optical material capable of changing to at least two states having at least two polarization states, and the second material is changeable to at least two states having at least two crystallization levels. Phase change material,
The data storage device further includes a plurality of data axes formed substantially perpendicular to the second surface of the first recording layer, and each of the plurality of data axes is included in the first plurality of data storage locations. And a data axis extending through a corresponding one of the second plurality of data storage locations; and
A processed beam having first and second beam characteristics is processed from a laser beam directed toward the first recording layer and the second recording layer along one of the plurality of data axes, the laser beam Is first processed with one of at least two states determining the first beam characteristic by a corresponding one of the first plurality of data storage locations, followed by a corresponding one of the second plurality of data storage locations. Processed with one of the at least two states that determine the second beam characteristic by the first and second beam characteristics of the processed beam, respectively, corresponding to one of the first plurality of data storage locations and A data storage device adapted to indicate a corresponding first and second data value of the second plurality of data storage locations. The first physical property of the first material is variable between two optical polarization levels, and is stretched between them to form a grade so as to have at least two polarization states. And
Changing at least two polarization states of the first material portion by changing a first physical property of a portion of the first material between two optical polarization levels;
This allows the first physical property of the first material to be varied by the heat generated by the laser beam on the portion of the first material and the magnetic direction of the magnetic field applied thereto. 47. A data storage device according to claim 46. 48. The data storage device of claim 47, wherein the magnetic field is generated by one of a permanent magnet and an electromagnet. The second physical property of the second material can vary between a generally crystallized state and a generally amorphous state, stretched between them to have at least two crystallized states and grades And changing at least one of the reflectance and transmittance of the portion of the second material by changing a portion of the second material between a substantially crystallized state and a substantially amorphous state. Can be changed,
49. This allows the second physical property of the second material to be varied by a laser beam having a certain size, the size of the laser beam corresponding to at least two crystallization levels. A data storage device according to any one of the above.

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