JP2005203046A - Information recording medium, information recording method and recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high-speed recording and high-density recording regarding an information recording medium, an information recording method, and an information recording device in which the information is recorded and reproduced utilizing a light beam. <P>SOLUTION: Voltage is applied to a recording layer sandwiched between a pair of transparent or translucent electrodes. The layer is arranged in which absorption or reflectance spectrum changes with applied voltage as the recording layer itself or other layer adjacent to the recording layer with a state where transmittance is high to the light beam for the recording or reproducing. The end of the transparent or translucent electrode is concentrically arranged at an inner circumference portion of the disc as the recording medium. This electrode is connected to the electrode on the surface of a substrate and the voltage is applied via the disc press or its neighborhood having the electrode corresponding to this. A group of slip rings are used which can move a brush from an immovable part to a movable part of a drive device. When multibeam parallel recording is performed, speeding up is made possible. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an information recording medium that records and reproduces information using light, an information recording method, and an information recording apparatus.

  An optical disc is characterized in that the recording medium (disc) can be removed from the recording / reproducing apparatus and the recording medium is inexpensive. Therefore, it is desirable to increase the speed and density without losing this feature in the optical disc apparatus.

  There are various known principles for recording information by irradiating the recording film with light. Among them, the recording layer containing a dye having absorption at the wavelength of the recording light source and the substrate surface in contact with the recording layer are altered by laser irradiation for recording. Optical discs with a recording layer made of an organic material that performs the above are most shipped at a low price. This type of optical disc includes a CD-R and a DVD-R.

On the other hand, those using atomic arrangement changes due to heat, such as phase changes of film materials (also called phase transitions or phase transformations), have the advantage that an information recording medium that can be rewritten many times can be obtained. For example, as described in Japanese Patent Laid-Open No. 2001-344807, the basic configuration in the case of these phase change optical discs includes a protective layer, a GeSbTe-based recording film, a protective layer, and a reflective layer on a substrate. Among the phase change optical disks, a recording layer of Te oxide having a high transmittance is used, and as with the DVD-R, a multi-layered structure of up to four layers that cannot be rewritten but can be written once is under development. It has been reported.
JP 2001-344807 A

  In order to increase the effective recording density (effective surface density) of an optical disc, it is desirable to make multiple layers taking advantage of the light's long reach and transparency. However, in the case of three or more layers, the transmittance and recording sensitivity of each layer are traded. The relationship was off, and either the playback signal quality or the recording sensitivity had to be sacrificed. The layer spacing is required to be 20 μm or more so that the light spot is sufficiently spread in adjacent layers and information is not mixed at the time of reading. There is also known a transparent organic or inorganic material that performs three-dimensional recording including the thickness direction. However, if two-photon absorption is used, the recording medium is a single crystal and is expensive and easily broken, and the recording sensitivity is poor. Causes diffraction and scattering of light. In addition, since the recording medium is thick, the optical system is different from the optical disk and becomes a confocal optical system.

  An object of the present invention is to solve these problems and achieve stable large-capacity high-speed recording.

  In order to achieve the above object, the present invention adopts a system in which a plurality of laminated electrochromic materials are made transparent or colored by voltage, and only the colored layer can be recorded / reproduced. Recording is performed by changing only the portion irradiated with the high-power pulse laser beam to a state in which coloring is not applied even when a coloring voltage is applied. The optical system has the advantage that the optical system of the conventional optical disk can be used, but it is necessary to apply a voltage to the disk and apply a current, so how to apply the voltage to the rotating disk and record at high speed Is a problem. In order to solve this problem, in the present invention, the disk mounting portion fixed to the recording medium rotating shaft for mounting the recording medium of the drive device, or the disk pressing portion for pressing and fixing the disk or the vicinity thereof is used. A recording medium capable of applying a voltage to a plurality of electrodes of the recording medium and a drive device are provided.

  An information recording apparatus according to the present invention includes a rotating shaft, a disk mounting portion fixed to the rotating shaft, and a disk-shaped recording medium mounted on the disk mounting portion. The rotating disc holder and the electrode exposed to the disk contact surface of the disk mounting portion, and the electrode sandwiching the recording layer of the disk-shaped recording medium mounted on the disk mounting portion, or other conductive material A plurality of pin-shaped or strip-shaped contact electrodes that are in contact with each other, a power source, and a conductive path that is connected to the power source and feeds power to the plurality of pin electrodes.

  An information recording apparatus according to the present invention includes a rotating shaft, a disk mounting portion fixed to the rotating shaft, and a disk-shaped recording medium mounted on the disk mounting portion by pressing and fixing the disk-shaped recording medium. The disc pressing portion that rotates as a unit, and the electrode that is exposed on the disc contact surface of the disc pressing portion and sandwiches the recording layer of the disc-shaped recording medium placed on the disc placement portion, or other conductive material A plurality of pin-shaped or strip-shaped contact electrodes that are in contact with each other, a power source, and a conductive path that is connected to the power source and feeds power to the plurality of contact electrodes.

  The plurality of pin electrodes are preferably biased in a direction protruding from the disk contact surface. The conductive path may be installed in the rotating shaft or in the disc pressing portion. Both of these may be passed from one to the other. Moreover, it may have an elongate conductor whose contact position is movable in the longitudinal direction in contact with the rotating shaft, and the conductor may constitute a part of the conductive path.

  An information recording method according to the present invention includes a step of placing a disk-shaped recording medium having a plurality of recording layers that develop color by applying a voltage sandwiched between a pair of electrodes, on a disk mounting portion fixed to a rotating shaft; A step of pressing and fixing the disc-shaped recording medium placed on the placing portion by a disc pressing portion that rotates integrally with the disc-shaped recording medium; and a disc contact surface of the disc placing portion or a disc holding portion. A voltage in a direction in which the recording layer sandwiched between the plurality of pin-shaped or strip-shaped contact electrodes provided on the disk contact surface sandwiches one of the recording layers is colored. And a step of selectively recording information on a recording layer sandwiched between a pair of electrodes to which a voltage is applied by irradiating a disk-shaped recording medium with light. The recording layer that develops color when voltage is applied contains an electrochromic material. You may apply the voltage of the direction which increases the transmittance | permeability of the recording layer pinched | interposed to the electrode pair which pinches | interposes recording layers other than the recording layer which selectively records information. In the present invention, color development is defined as an increase in absorption with respect to the wavelength of laser light used for recording or reproduction. Therefore, it may be colored before color development.

  The information recording medium of the present invention can be significantly multi-layered as compared with the prior art, and can reduce electrical displacement and reliably realize electrical connection from the drive device to the recording medium, increasing the effective recording density. High-speed recording is possible, and the recording capacity per recording medium can be greatly increased. The recording / reproducing apparatus of the present invention can perform high-speed recording / reproducing with a large capacity and a long life.

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

  The configuration of the recording medium of the present invention is specifically as follows. As shown in FIG. 1, a metal reflection layer 2 is first formed on a substrate 1, and then a first transparent electrode 3, an electrochromic material layer 4, a solid electrolyte material layer 5, and a second transparent electrode 7 are arranged in this order. If necessary, two or more sets of the films formed in (1) are laminated with the spacer layer 6 interposed therebetween. When a voltage is applied between the electrodes sandwiching the recording layer, it is preferable to increase the absorptance and reflectance of the recording or reading laser beam. Thereby, only an arbitrary layer can absorb light, and the other layers can hardly absorb light. Thereby, since there is no interference of other layers, the film thickness per layer can be reduced to about 1/100 of the conventional thickness, and a plurality of layers can be arranged within the focal depth of the focusing lens. Multi-layer and larger capacity than disk. Of course, recording and reproduction may be performed by moving the focal position so that the layers other than the first and second layers do not fall within the focal depth. In such a case, since pits and grooves representing address information may be deformed when multilayered, a plurality of laser beams may be used, and one beam is focused on the reflective layer immediately above the substrate. It is preferable that the focal position of another beam whose positional relationship in the in-plane direction is substantially fixed be on the recording or reproducing layer. In the case of a multi-layer medium, it is necessary to read the address at the moved focal position by providing a layer with transferred pits and grooves again. When the reflectivity of the electrochromic material layer is high, the metal reflective layer may be omitted. Finally, it is bonded to another similar substrate.

  Examples of the electrochromic material include tungsten oxide and a polymer of thiophene organic molecules (polythiophene and derivatives thereof). Furthermore, as the electrochromic material, many electrochromic materials that have been published at present are used, such as various materials described in "Electrochromic Display" published on June 28, 1991 by Sangyo Tosho Co., Ltd. Is possible. Due to high recording sensitivity, even in the case of high linear velocity recording, or when an array laser or surface emitting laser is used as a means for simultaneously irradiating light on multiple locations (including multiple layers) on a recording medium However, high transfer speed can be realized without power shortage. A voltage may be applied to a plurality of electrode pairs of the recording medium alternately or sequentially in at least two pairs simultaneously or in pulses. This can be achieved by using a material that changes its color unless a low sustain voltage or intermittent sustain voltage is applied, or by simultaneously recording and reproducing multiple layers by positioning the focal position of each beam of the array laser in each layer. This is necessary when using some beams as a reference for focusing or tracking.

  A recording medium having a plurality of recording layers is used, and a voltage is applied between many electrode pairs. At the time of recording, erasing, or reading, only the electrodes on both sides of the layer on which the recording is performed differ from the other electrodes. Apply voltage. The different voltage includes a voltage having a reverse polarity.

  Further, in the present invention, the electrochromic material layer is a definition of a layer of a material that directly develops color (changes absorption or reflection spectrum) when voltage is applied (current flows). A material not currently called an electrochromic material may be used. However, when the layer has a thickness of 50 nm, at least one of recording and reproduction, preferably both, the light absorption can be reduced to 10% or less, more preferably 5% or less when a predetermined voltage is applied to the light wavelength. . In addition, a layer including a region that emits light when voltage is applied (current flows) and a region that emits or decolors by receiving the light may be included.

  FIG. 10 shows another configuration example of the recording medium according to the present invention. In this recording medium, a reflective layer, a transparent electrode, a conductive organic material layer, a solid electrolyte layer, and a transparent electrode are formed in this order, and two or more sets other than the reflective layer are repeatedly laminated on the substrate.

  The transparent electrode of each layer or the end of the electrode extended from the transparent electrode is formed on the inner periphery of the disk so as to be concentric. You may make it become radial as shown in FIG. In the case of a radial shape, it is preferable to provide two or more radial electrodes in one transparent electrode layer in order to avoid voltage non-uniformity due to the surface resistance of the transparent electrode.

  As shown in FIG. 2, it is preferable that a plurality of metal pins 16 penetrating the substrate are provided on a part of at least one of the substrates 14. The metal pin is connected to the concentric electrode 15. The opposite side of the metal pin is connected to a plurality of transparent electrodes 12 on the film forming substrate 11 by a conductive material 13. The metal pin does not have to be a literal pin shape, and may be a belt-like metal such as an arc shape or an annular shape whose center coincides with the disc center. Further, it is not essential to penetrate the substrate, and the vicinity of the center hole of the disk may be bypassed.

  The concentric electrodes or the concentric lead portions of the transparent electrode may not be continuous, but a plurality of electrodes may be arranged on each circle. The end portion (concentric portion) of the transparent electrode may be coated with a material containing metal or carbon fine particles to improve conductivity and reinforce.

  FIG. 3 is a diagram showing the structure of a multilayer disk recording / reproducing apparatus according to an embodiment of the present invention. This multi-layer disc recording / reproducing apparatus is an information recording apparatus that records information by giving information in a concave-convex shape in advance to the recording medium or by applying energy such as light to the recording medium. FIG. 19 is a diagram showing an example of a multilayer recording medium in which information is given in advance in the form of irregularities on the recording medium. This device comes out of the voltage transmission mechanism from the stationary part of the recording / reproducing apparatus to the rotating shaft 31 below the disk mounted on the disk receivers (disk mounting portions) 24, 24 ', and rotates the rotating shaft. Drive device through a lead wire 21 toward the shaft tip, a pin-shaped, concentric circular, concentric cylindrical or conical frustum-shaped electrode 25 corresponding to the number of electrodes on the disk at the tip of the rotating shaft, a ball bearing 28 and an arm 27 The disk retainer 23 that is fixed to the disk and rotates together with the rotation shaft while pressing the disk, the pin shape of the rotation shaft provided on the disk retainer, the concentric circle, the concentric cylinder, or the conical cone Concentric, pin, or concentric cylindrical or conical conical cylindrical electrode 22 corresponding to the trapezoidal electrode, and a metal pin electrode with a built-in spring corresponding to the concentric electrode on the inner periphery of the disk With 9. However, at least one of the electrodes of the rotating shaft top and the disk presser that are in contact with each other is not pin-shaped but concentric or concentric circles are further divided into arcs, and when the disk is inserted into the drive device, the disk Means for moving the presser toward the disk and controlling it to contact the concentric electrodes on the inner periphery of the disk and the top of the rotating shaft is provided. In FIG. 3, it is difficult to understand if many electrodes near the disk presser are written, so only three are written. Reference numeral 30 denotes a connection portion between the ball bearing and the disk presser.

  The concentric, concentric cylindrical or concentric frustoconical electrodes may not be continuous, and a plurality of electrodes may be arranged on each circle. The electrode may be a wedge-shaped metal piece. The lead-out portion to the inner periphery of the transparent electrode may be formed by applying a material containing metal or carbon fine particles on the transparent electrode.

  FIG. 4 is a structural diagram showing another example of a multilayer disk recording / reproducing apparatus according to the present invention. This apparatus is an information recording apparatus that records information by giving information in a concave-convex shape to the recording medium in advance, or by applying energy such as light to the recording medium, and includes a disk receiver (disk mounting portion) 48, A lead wire 40 arranged from the spring built-in pin electrode 41 arranged at 48 'toward the tip of the rotating shaft, and the lead wire is connected to a laminated cylindrical electrode 49 or a truncated cone-shaped electrode corresponding to the number of electrodes of the disc at the tip of the rotating shaft. Means for contacting the plurality of electrodes 47 on the apparatus side with rotating laminated concentric cylindrical or conical cylindrical electrodes corresponding to the number of electrodes of the disk, and holding the disk when rotating the disk together with the rotating shaft A rotating disk presser 44 is provided. The pin electrode does not have to be in the form of a pin (thin column or cylinder), and may be, for example, a belt-like electrode that forms an arc. In FIG. 4, it is difficult to understand if a large number of electrodes near the disk receiver are written, so only three are written. Each of the plurality of electrodes on the device side is narrow and long, and the whole is in the form of one long belt, and the contact position can be changed when the contact portion with the rotating electrode is worn.

  Each of the concentric, concentric cylindrical, or conical frustum-shaped electrodes may not be continuous, and a plurality of electrodes may be arranged on each circle.

  FIG. 6 is a diagram showing the structure of a multilayer disk recording / reproducing apparatus according to one embodiment of the present invention. This apparatus is an information recording apparatus that records information by giving information to the recording medium in the form of irregularities or by applying energy such as light to the recording medium, and passes through a rotation holding mechanism 62 such as a ball bearing. A disk holding means 63 that is fixed to the drive device by an arm 68 having a spring property, and that rotates together with the rotating shaft while pressing the disk when rotating the disk, the disk pressing means is a rotation holding mechanism such as the ball bearing or the like. Is electrically connected to the stationary part of the drive device through another slip ring-like voltage transmission mechanism 57, 67 (67 is a belt-like brush group), and corresponds to the concentric electrode of the disc provided in the disc pressing means. Pin electrode 59 with a built-in spring, a rotation holding mechanism such as the ball bearing or slip When the disk is inserted into the drive device, the disk presser is moved toward the disk and brought into contact with the concentric electrodes of the disk. It has a means to control. Each of the concentric electrodes of the disk may be further separated into a plurality of arcs in the circumferential direction. In FIG. 6, it is difficult to understand if many electrodes near the disk presser are written, so only three are written. FIG. 12 is a side view of the slip ring.

  A plurality of electrodes obtained by dividing each of the concentric electrodes may be formed by implanting wedge-shaped metal pieces.

  The recording medium (disc) may be a laminate of two discs, and a plurality of metal pins may penetrate through at least one substrate and may be connected to a plurality of electrodes formed on the substrate. Further, the inner diameter of one disk may be smaller than the inner diameter of the other disk, and concentric electrodes of the disk having the smaller inner diameter may be exposed at a portion of the inner diameter difference. However, in this case, it is desirable to reinforce the electrode on the substrate by applying or pasting a conductive material.

  The recording medium is provided with information in the form of irregularities in advance, or the recording medium for recording information by applying energy such as light to the recording medium has at least an electrochromic material layer between two transparent or translucent electrodes Information recording apparatus in which two or more sets are stacked, the recording medium is stationary, and the electrode on the recording medium side and the power source are connected by a connector having a plurality of metal contacts inside the insulator cover It is also good.

<Example 1>
(Configuration, manufacturing method)
A polythiophene-based material was used for the electrochromic material layer. Specifically, the polythiophene-based material layer contains about 80 vol% of HC Starck's product name Bytron P, the remaining main component is t-butyl alcohol, and a small amount of surfactants NS210, polyvinyl alcohol, 3-GPTMS. It is the layer which apply | coated and heat-dried the liquid containing (3-glycidoxypropyltrimethylsilane). A solid electrolyte material is laminated thereon. The solid electrolyte material is made of PMMA (polymethyl methacrylate) and lithium triflate (lithium trifluorosulfonate) as the main components and coated with a small amount of propylene carbonate, ethylene carbonate, acetonitrile, cyclohexanon and Hitachi Chemical's UV curable resin H-9. And then UV-irradiated and heat-dried. Since it is formed by coating, the film thickness is reduced at the land portion of the substrate and is increased at the groove portion. The electrochromic material layer is colored by applying a voltage between the upper and lower electrodes. When a blue laser having a wavelength of about 405 nm was used as the light source, a polyaniline-based material (derivative) was used.

  This medium was manufactured as follows. First, a land / groove recording groove (width: 0.615 μm) having a diameter of 12 cm, a thickness of 0.6 mm, a track pitch of 0.615 μm, and a depth of about 70 nm is formed on the surface. A polycarbonate substrate having a header portion indicating addresses, synchronization signals and the like by pit rows at the beginning of each sector and a clock expressed by a wobble in the groove was used. The substrate is almost the same as the DVD-RAM substrate. The use of a lake substrate is not necessarily optimal, and it is more preferable to use a substrate having a format that hardly affects even when there is crosstalk between layers. For example, a sample servo format substrate. FIG. 17 is a schematic plan view of the groove.

As shown in FIG. 1, the Ag ₉₄ Pd ₄ Cu ₂ translucent reflective layer 2 is 20 nm thick, the ITO transparent electrode 3 is 100 nm, the electrochromic material layer 4 is 100 nm, and the solid electrolyte layer 5 is formed on the polycarbonate substrate 1. 100 nm, WO ₃ protective layer 6 50 nm, ITO transparent electrode 7 100 nm, and then repeat in the same manner, electrochromic material layer, solid electrolyte layer, WO ₃ protective layer, ITO transparent electrode, electrochromic material layer, solid electrolyte layer , WO ₃ protective layer, ITO transparent electrode, an electrochromic material layer, solid electrolyte layer, WO ₃ protective layer, and the recording layer sandwiched on both sides by ITO transparent electrode in this order ITO transparent electrode stacked five layers. During film formation, the transparent electrode, each layer between the next transparent electrode, the transparent electrode, and the inner peripheral mask were sequentially enlarged so that each transparent electrode was concentrically exposed on the inner peripheral portion of the disk. Each layer on the transparent electrode and the transparent electrode thereon may be formed in the same mask shape. Furthermore, a substrate having an inner diameter (diameter) of 15 mm and an outer diameter of 41 mm, with electrodes penetrating from the front to the back, and a polycarbonate substrate having an inner diameter of about 41 mm, an outer diameter of 120 mm, and a thickness of 0.6 mm were attached to the outer circumference. . Light was incident from the side of the laminated substrate. The inner peripheral substrate and the outer peripheral substrate may be integrated to form a single polycarbonate substrate.

The ITO transparent electrode was formed by sputtering, and the WO ₃ protective layer was formed by vacuum deposition. The reason why the vacuum deposition is used is to protect from ion bombardment during sputtering when the underlying layer is made of an organic material, and to prevent a high resistance layer from being formed due to oxygen being taken away by the organic material layer. . Deterioration of characteristics became faster when subjected to ion bombardment. The thickness of the WO ₃ layer is preferably thin (about 30 nm) in terms of light transmittance. The ITO transparent electrode can also be formed by electron beam vapor deposition or laser vapor deposition (a method of evaporating and forming a film by irradiating a target with high-power laser light, also called PLD method). _{The three} layers can be made thinner than 50 nm or omitted. However, the ITO film formed by vapor deposition is slightly lower than the sputtered ITO film in terms of transmittance and conductivity. For the purposes of protection, vacuum deposition, or known transparent conductive inorganic material can be formed by coating can be used in place of WO _3.

The WO ₃ protective layer can be used not only as a protective layer but also as a light reflecting layer for autofocus and / or tracking and / or reproduction. This is because this layer is also colored by voltage application, and the reflectance tends to be high. When used as a light reflecting layer, it may not be added to all the recording layers, but may be provided every other plural layers such as every other layer or every other two layers. It is desirable to attach it to a layer to which irregularities such as grooves are transferred. In such a case, the servo signal is obtained from a laser beam focused on the light reflection layer, and the reproduction signal is obtained from a beam focused on the same or another layer. These beams may be the same single beam.

  The period from the transparent electrode to the transparent electrode was about 0.4 μm. The period of 0.1 μm or more is necessary for preventing the change of the recording state due to thermal diffusion to the adjacent layer. The range of 15 μm or less was necessary in order to prevent optical problems such as a collision failure and aberration of the lens with the substrate. A more preferable range was 0.2 μm or more and 2 μm or less. If it is 0.4 μm or less, the laser element interval is not widened, and no optical problem occurs even if a one-chip array laser is used as it is. It is also possible to provide the array laser with a step corresponding to the layer period of the disk for each element so that the laser element is perfectly opposed (parallel) to the disk.

  Although voltage can be applied to each layer from a separate power source for each layer, the number of power sources can be reduced and power consumption can be reduced as follows. That is, as shown in FIG. 5, the voltage is applied by sequentially applying intermittent pulsed negative voltage (negative on the solid electrolyte side) to each layer from one power source. When selecting a layer to be recorded / reproduced, a plus voltage is applied in this order or even if this order is disturbed for the time width necessary for recording / reproduction. Return to the negative negative voltage application sequentially from the layer where the negative voltage should have been applied. Since the speed of natural coloring when the voltage is removed is slow, a high transmittance can be maintained on average even when an intermittent negative voltage is applied. FIG. 16 is a diagram showing another method of sequentially applying intermittent voltage from the single power source to each layer of the multilayer disk of the present invention. When the recording layer is made of a material or a layer structure that rapidly disappears in 5 seconds or less when the voltage is removed, the above intermittent negative voltage application is not necessary.

Each recording layer may have a three-layer structure in which one more layer is added on the solid electrolyte layer. In the case of the three-layer structure, for example, IrO _x or NiO _x which is an oxidation color development type first color development layer (x is a positive number less than 1). ) Layer 150 nm, a solid electrolyte layer Ta ₂ O ₅ layer 300 nm, and a reduction coloring type second coloring layer WO ₃ layer 200 nm. In the case of two layers, for example, two layers of an OH ion storage layer 200 nm made of Cr ₂ O _{3 and a} coloring material layer 200 nm made of IrO _x are used. A metal electrode such as W-Ti may be used instead of the transparent electrode farthest from the light incident side. When the electrochromic material layer is formed by coating, the groove is gradually filled by lamination, and the distance between the electrodes on both sides of the recording layer is closer to the land portion than to the groove portion. The electrolyte layer is a layer in which positive ions such as hydrogen, lithium, sodium, and magnesium are stably held and moved inside.

The material used for the electrochromic material layer is preferably an organic material such as a thiophene-based organic oligomer or polymer. In particular, a conductive organic material is preferable. For example, in the case of a thiophene polymer such as BaytronP (polyethylenedioxythiophene), the laser wavelength was set to 660 nm. The polymer of thiophene is formed by coating, vacuum deposition or electrolytic polymerization. In the electropolymerization, poly (3-methylthiophene) which is a thiophene derivative is used as a monomer, LiBF ₄ is used as a supporting electrolyte, and benzonitrile is used as a solvent. On the other hand, if polyaniline is used, a large reproduction signal can be obtained with a blue (wavelength of about 400 nm) laser.

The recording layer of the present embodiment is composed of a solid electrolyte made of a material obtained by mixing an acrylic ultraviolet curable resin with Li triflate (formal name: Li trifluorometanesulfonate: CF ₃ SO ₃ Li) and a plasticizer. And a layer of PEDT / PSS, that is, an electroactive conductive polymer coloring material layer made of a mixed material of poly (3,4 etylenedioxythiophene) and poly (stylene sulfonate).

Another example of the layer structure is described in Helmut W. Heuer et al., Advanced Functional Materials vol.12, No.2 pp89-94 (Feb. 2002), electrochromic Window Based on conducting Poly (3,4-ethylenedioxythiophene) Among the materials and layer structures described as the coloring control window glass material in the paper of -Poly (styrene sulfonate), an ion storage / dark current blocking layer composed of (CeO ₂ ) ₆₇ (TiO ₂ ) ₃₃ , Li triflate ( full name Li trifluoromethane _{sulfonate, Li trifluoromethansulfonate: CF 3 SO 3} Li) electrolyte layer, and PEDT / PSS layer or made of mixed material of poly and (3,4 etylenedioxythiophene) and poly (stylene sulfonate) It is three layers of an electroactive conductive polymer coloring material layer. Before forming the thiophene-based polymer layer, if the end of the thiophene-based polymer is subjected to a treatment for attaching any of a cyano group (—NC), a thiol group (—SH), or an S-acetyl group (—SAc), preferable. This is because the longitudinal direction of the thiophene polymer is oriented as much as possible in the film thickness direction so that a current in the film thickness direction can easily flow. As the organic electrolyte layer, a polyethylene oxide-potassium thiocyanate system is also preferable.

  Instead of the above PEDT / PSS layer, Electrochromic Linear and StarBranched poly (3,4-ethylenedioxychiophene-didodecyloxybenzene) Polymers in Micromolecules vol.33 pp2083-2091 (2000) by Fei Wang et al. When Star-branched poly (3,4-ethylenedioxychiophene-didodecyloxybenzene) (abbreviation SPEB), which is a polythiophene-based polymer material that develops color, is fast in color development / decoloration and good characteristics can be obtained. The above electrolyte is used as the electrolyte.

  When a dielectric or semiconductor layer made of a transparent oxide or the like is provided between the solid electrolyte layer and the electrochromic material layer, it acts as a barrier layer for Li ions, and Li ions are captured by the electrochromic layer and become solid. Coloring / decoloring repeated deterioration factors such as not returning to the electrolyte layer side can be suppressed. For example, a chromium oxide layer having a thickness of about 10 to 50 nm may be used.

  The electrolyte layer and the electron active conductive polymer coloring material layer can be further formed by forming a thiophene polymer layer by field polymerization and incorporating a dopant such as Li triflate into the film. It is preferable to add a difference in the film thickness direction to the dopant concentration.

The merit of using the organic material layer described so far is that it has conductivity, conductivity increases with increasing temperature, and can also have photoconductivity, so photocarriers are accelerated by an electric field and the temperature increases That is, it is possible to promote coloring and increase the recording sensitivity, and it is not necessary to enter and exit the film for color decoloration as in WO ₃ . Coloring occurs when polarons due to positive charges are extinguished by the incorporation of electrons into the molecule, and the energy difference from the excited state corresponds to the energy of visible light. In order to assist this electron transfer, ions such as Li ions and hydrogen ions (protons) move. It is also preferable to vaporize a monomer or a low molecular weight having a few molecules bonded thereto to form an oligomer or polymer on the substrate by high-speed vacuum deposition. To make an oligomer or polymer on the substrate, the molecules are excited by irradiating with blue or near ultraviolet light during vacuum deposition. In addition to thiophene polymers (polythiophene for short), metal phthalocyanines such as Lu-diphthalocyanine, heptyl viologen, tungsten succinate complex, styryl compounds 3,3dimethyl-2- (P-dimethylaminostyryl) indolino [2, 1-b] oxazoline (IRPDM) (light source wavelength 5145 nm), 3,3 dimethyl-2- (P-dimethylaminocinnamylidenevinyl) indolino [2,1-b] oxazoline, polyaniline and poly for blue laser recording and reproduction (Laminated film with 2-acrylamido-methane-2-propanesulfonic acid (abbreviated PANPS)) (described in the paper by Advanced Materials Vol.13, No. 19, 1455 (2001) by D. DeLongchamp and PT Hammond) etc. It can be used. Furthermore, a layer of TCNQ (7,7,8,8-Tetracyanoquinodimethane) may be formed to provide a photoconductive effect. When these organic substances were used, the other parts of the disk were the same as in the above example.

As an inorganic electrochromic material to replace WO ₃ , Prussian blue (K _x Fe ^II _y Fe ^III _z (CN) ₆ , MoO ₃ , Nb ₂ O ₅ , V ₂ O ₅ , TiO ₂ , NiOOH, CoOOH, Rh ₂ O ₃ , IrO _x (x is a positive number less than 1), ZrNCl, InN, SnN _x (x is a positive number less than 1), MnO _x (x is a positive number less than 2) ), WO ₃ —MoO ₃ composite (mixed) thin film, etc. These materials can also be used in place of WO _{3 for} the protective layer.

When an inorganic material is used for the electrochromic material layer, both the organic material as described above and the inorganic material described below can be used as the solid electrolyte material. Thus, there is an advantage that it can be unified by a dry (vacuum) process such as sputtering, vacuum deposition, and electron beam deposition. Sputtering is particularly preferable because of high reproducibility of film formation. For example, a structure in which one of the following laminated films is sandwiched between transparent or translucent electrodes is employed. _{WO 3 -Ta 2 O 5 -IrO x} , WO 3 -Cr 2 O 3, WO 3 -MgF 2, WO 3 -RbAg 4 I 5, WO 3 -SiO, WO 3 -ZrO 2, WO 3 -LiClO 4, _{WO 3 -LiF, WO 3 -Na 3} Zr 2 Si 2 PO 12 (NASICON), and the like WO 3 -NaYSi ₄ O _12. These are materials described in Science Forum, Yoshio Taniguchi, “Organic Electronics Materials, Current Status, Fundamental Technologies, Research Strategy” on August 85, 1986, 1st Edition, 1st printing, pages 85-86. Those using ₂ O ₅ are those described on pages 168-186 of Seiyo Bunko Co., Ltd., Nobuyoshi Baba et al., “Electrochromic Display”, 1991. One part or all of these WO ₃ may be replaced with other inorganic electrochromic materials such as MO ₃ .

  The use of a laminated film made of all of these inorganic materials is also effective for a layer-selective multi-layer optical disk device that uses a voltage other than the configuration of the present invention for the voltage transmission path.

  In an electrochromic material, when a current such as a metal such as Li or a cation such as hydrogen moves from a predetermined place or most of the electrons in the ground state in the light spot are excited, light absorption is automatically performed. Since the current decreases and the current hardly flows, it is possible to prevent a large current from flowing through the entire disk or an excessive current from flowing in the light spot irradiated portion to make the recording mark too large. That is, as a phenomenon, when light is applied while applying a voltage between the first electrode and the second electrode, the current near the irradiated area increases, and the voltage continues to be applied even after the light irradiation ends. In this case, the current decreases after a certain time, and a change in the state of the recording layer (electrochromic layer or the like) is observed. In some cases, the current automatically decreases during light irradiation.

  The electrochromic material may be one that is not currently called an electrochromic material, as long as the absorption or reflection spectrum changes depending on the voltage. For example, an effect such as the Franz Keldish effect that occurs in crystals may be used. Small disks and recording media can be made even with single crystals. However, it is preferable to use light absorption of 10% or less, more preferably 5% or less in the state of less absorption.

  Instead of the electrochromic material, a mixed material of an electroluminescent (EL) material and a photochromic material may be used. The light emitted from the EL material changes the color of the photochromic material so that light absorption occurs with respect to the wavelength of recording or reading light. As the EL material, inorganic materials such as ZnO and organic materials can be used. For example, Vol. 33, No. 2 (June 1998) of Toyota Central R & D Review, pages 3-22. Among the organic EL materials described in the above description, materials that match the emission wavelength to discolor photochromic materials such as diallylethene and fulgide are used in combination with the photochromic materials. In the case of a layer of these organic materials, it is formed by a method such as vacuum deposition, vapor phase growth or coating. In the case of coating, it was sufficiently diluted with a solvent so that the film thickness difference would not become too large between the groove part and the part between the grooves. The organic EL material includes an electron or hole transport layer material and a light emitting layer material, and a doping material for improving efficiency. As the hole transport layer material, a starburst amine (m-MTDATA) in which trifellamine is a star-shaped molecule is used. ) Blue light is emitted by using a benzoxazole Zn complex (Zn (BOX) 2) film thickness of 40 nm as the light emitting layer material. This emitted light is preferably blocked by a transparent or translucent electrode so that it does not reach other layers.

  As the photochromic material, fulgide, diarylethene and the like can be used. In the case of fulgide, absorption occurs in the vicinity of a wavelength of 500 nm by blue light irradiation, so that recording can be performed with a Kr laser having a wavelength of 514.5 nm.

  An overcoat layer made of an ultraviolet curable resin was formed on the laminated film and bonded to another similar disk.

  When a voltage is applied to the transparent electrodes on both sides of a recording layer to be recorded or read out while irradiating a laser beam having a wavelength of 660 nm, only the layer is colored so that the laser beam is absorbed and reflected. Therefore, information can be selectively recorded and read out. FIG. 14 is a block diagram of a switching circuit for applying a voltage to a desired recording layer. The voltage application is not necessarily limited to only one recording layer. When recording is simultaneously performed on a plurality of recording layers by an array laser, a voltage is applied between a plurality of pairs of electrodes. When simultaneous recording was performed using, for example, a four-element array laser as the laser light source, the data transfer speed could be increased nearly four times. When simultaneously recording on a plurality of recording layers with an array laser, a voltage in a coloring direction is applied between a plurality of pairs of electrodes simultaneously or sequentially. Further, if the voltage between the electrodes of the recording layer that is not recorded is set to a finite value without setting it to 0, it is possible to prevent the coloring from taking time due to the capacitance between the electrodes and the response speed of the coloring material.

  The thickness from the transparent electrode to the transparent electrode of each layer is reduced to a thickness that is about the depth of focus of the lens, and when the color is developed so that the light absorption coefficient increases toward the back layer, the focal position is moved in the depth direction to record in high density. Convenient to do. Further, if the thickness of each layer is made a little thinner, it is advantageous for volume hologram recording and the like. The light absorption coefficient of each layer may be made substantially the same to reduce the film thickness, and multi-level recording may be performed so that only the layer close to the incident side is recorded in the low power irradiation up to the back layer in the high power irradiation.

  A reverse voltage was applied to erase the color. It is also a feature of the present invention that the distribution of the light absorption coefficient of each layer during recording and reproduction can be changed. At the time of recording, the electrochromic material concentration of each layer and the coloring voltage application time to each layer are set so that the absorption rate when measured with a single layer is 20%, 30%, 40%, and 50% from the light incident side. In other words, when all layers are made uniform at 20% during reproduction, it is advantageous because the light reflected by the Ag-Pd-Cu reflective layer contains the information of each layer uniformly.

  For example, in the case of the present embodiment, if the four layers are divided into two groups and the electrochromic layers in the same group are colored and decolored at the same time, it is necessary for color development and decoloration. Time can be shortened. Within the same group, better recording characteristics can be achieved by adjusting the voltage and the degree of dilution of the electrochromic material with an acrylic polymer so that the light absorption rate of the layer farther from the light incident side is higher as described above. can get.

  As another method to prevent the time required for color development / decoloration from becoming a limiting factor for recording / reproduction speed, color development is performed sequentially from the back layer as viewed from the light incident side, and color erase is performed sequentially from the previous layer. Is effective. In this way, it is possible to prepare the color by starting to apply voltage to the adjacent layers during the color development of one layer, and the speed can be increased. In addition, the coloring and decoloring are caused by the surface resistance of the transparent electrode sequentially from the lead electrode side of the disk (in this embodiment, the inner circumference side), so this can be used or the radial direction of the disk can be divided into a plurality of zones. For example, when recording a continuous moving image by dividing the transparent electrode, the waiting time can be shortened by performing coloring or decoloring in accordance with the progress of recording. In this case, an insulating layer is required between the transparent electrodes in each zone.

  Recording is performed such that the electrochromic action of the film is lost by the action of laser light and / or current, and no color is developed even when a voltage is applied, or the absorption spectrum is different from that before recording. On the contrary, recording may be performed by increasing the color development, but when the voltage is set to 0 or a reverse voltage is applied, it is necessary to be in an optically same state as an unrecorded portion so that the recording cannot be seen. There is.

When recording is performed such that the electrochromic layer or the solid electrolyte layer changes phase between crystal and amorphous or between crystal and crystal, rewriteability can be expected. If the coloring or decoloring speed can be changed by an order of magnitude or more depending on the phase, it is possible to read out by reading only the region in either phase after voltage application. In the case of an inorganic material such as WO ₃ , positive ions are easier to move and the speed is higher in the amorphous state.

As another method, an organic or inorganic material in which at least one of a refractive index and an extinction coefficient is changed by a physical change (phase change, etc.) due to heat or electric current, or a chemical change (for example, reaction with Li ion). A layer may be stacked as another layer, and recording may be performed by changing the layer. For example, it is preferable to use a phase change recording film having a composition of In ₅₀ Se ₄₅ Tl ₅ because the transmittance is high with respect to light having a wavelength of 780 nm or 660 nm, particularly light having a wavelength of 780 nm. At the time of recording, it is indirectly heated by light absorption of the electrochromic material layer. Although the electrochromic material layer has photoconductivity although it is large or small depending on the material, the heating effect by the current of the photocarrier also occurs. When the phase change recording layer is provided, the phase change recording layer undergoes crystallization or amorphous phase change by heating. Since the phase change recording layer has a high refractive index, the thickness of the transparent electrode layer is preferably selected to have an antireflection effect in order to prevent reflection at the interface. By optically designing the refractive index change due to the phase change so that it can be easily seen as a difference in reflectance particularly when the electrochromic layer is colored, each of the multilayer recording films can be read out almost independently.

  As yet another method, a magnetic material whose magnetization direction is changed by heat or current and a magnetic field may be formed as a recording layer adjacent to the electrochromic material or the solid electrolyte material. For example, a transparent magneto-optical material such as garnet is conceivable, and the design is such that the difference in Kerr rotation angle increases as the temperature rises.

  It is preferable that the optical film thickness from the transparent electrode to the transparent electrode is approximately one wavelength or an integral multiple thereof with respect to the wavelength of the readout light, since any recording layer is optically equivalent.

(Other examples of transparent electrodes)
As a material for the transparent electrode, a composition of (In ₂ O ₃ ) _x (SnO ₂ ) _1-x , where x is in the range of 5% to 99%, and more preferably, x is 90%. To 98% of material, to which 50% or less of SiO ₂ is added, to SnO ₂ to which other oxides such as 2 to 5% of Sb ₂ O ₃ are added, A known transparent electrode material such as can be used.

Further, if the transparent electrode between the recording layers is divided into two layers and a heat insulating layer is provided between them, and the heat insulating layer is also an organic material, it is optically preferable for the same reason as described above. The heat insulating layer may have electrical conductivity, but it is more preferable that the heat insulating layer does not exist, and many materials such as an acrylic oligomer, a polymer, and a vacuum deposited film of metal phthalocyanine can be used. An inorganic material such as ZnS—SiO ₂ may be used. In addition, a conductive organic material layer whose absorption edge changes with a temperature rise by current or a preheated laser beam may be used.

  In a small recording medium in which a large sheet resistance is not a problem, the transparent electrode can be formed of a conductive polymer such as polyacetylene or polythiophene. In this case, the refractive index difference with the electrochromic layer is smaller than that of the inorganic transparent electrode, which is preferable in that adverse effects such as interference of light reflected at the interface can be avoided. A hydrophobic surface treatment agent, a silane coupling agent, or a thin copper group element (Cu, Ag, Au) layer having an average thickness of 0.5 to 3 nm may be provided as the underlayer.

(Other examples of substrates)
In this embodiment, a polycarbonate substrate 77 having a tracking groove directly on the surface is used, but the recording / reproducing wavelength is λ on the whole or part of the substrate surface with the substrate having the tracking groove. In some cases, the substrate has a groove having a depth greater than or equal to λ / 15n (n is the refractive index of the substrate material). The groove may be formed continuously in one round or may be divided in the middle. It has been found that when the groove depth is about λ / 12n, it is preferable in terms of the balance between tracking and noise. Further, the groove width may vary depending on the location. It may be a substrate having a format capable of recording / reproducing in both the groove portion and the land portion, a substrate having a format in which recording is performed on either one, or a substrate having a sample servo format in which tracking servo marks are intermittently provided. In the type in which recording is performed only on the groove, it is preferable that the track pitch is about 0.7 times the wavelength / NA of the focusing lens and the groove width is about a half thereof.

  A spacer layer having a thickness of 20 to 40 μm may be sandwiched between several layers of the multilayer recording layer (for example, it is particularly preferable that every five layers match the number of beams or the number of beams−the number of pre-irradiated beams). It is preferable to transfer a concave / convex pattern including at least one of tracking grooves and pits from a nickel stamper to the spacer layer and use it for detection of a tracking signal, an address, a clock, a synchronization signal, and the like. Apply a thin layer of electrochromic material or solid electrolyte material on the pattern transferred to the spacer layer, so that the thickness of the layer is thick at the concave portion and thin at the convex portion, so that the electrochromic material layer and the solid electrolyte material layer When both are applied to form a structure sandwiched between the transparent electrode layers, it is also preferable to detect the address signal and the like so that the concave portions are strongly colored when a positive voltage is applied. In this case, when two or more spacer layers are used, it is preferable to provide an element that compensates for spherical aberration in the optical system.

  When recording / reproducing light is incident from the bonded substrate side, the bonded substrate may be made as thin as about 0.1 mm and the NA of the focusing lens may be increased to 0.85. Then, the track pitch can be reduced to about 3/4.

When a separate photoconductor layer is provided, a very thin conductor layer (metal layer or transparent electrode layer) should be provided between the recording layer and the photoconductor layer in order to suppress mutual diffusion and reaction. The reliability increases during rewriting. However, an average film thickness of 1 nm or more and 10 nm or less is necessary so that photocarriers generated in the photoconductor layer penetrate. It may be a striped or network discontinuous film. For example, an electrode layer of Al or W ₈₀ Ti ₂₀ having a thickness of 5 nm is provided between the recording layer and the photoconductor layer. If an Al layer formed by vacuum deposition is applied after the recording layer is formed and before the transparent electrode is formed by sputtering, an effect of protecting the organic material from ion bombardment can also be obtained.

  For the transparent electrode in the recording area, the entire disk may be separated into one or a plurality of fan-shaped transparent electrodes, or may be separated concentrically in the radial direction. A voltage may be applied between the electrodes in the in-plane direction to cause coloring. Separation is preferable because the interelectrode capacitance is reduced, so that the voltage rises and falls earlier. Since the time and current required for color development and decoloration are in a practical range, the interelectrode capacitance is particularly preferably 0.1 F or less. However, in order to have good device characteristics, the structure is 0.01 F or more. Good to do. One transparent electrode of the pair of transparent electrodes may not be separated into a plurality, but one may be separated. Also, the upper and lower electrodes may be separated. In this case, the positions of the cuts between the upper and lower electrodes may be the same or may not be the same. The transparent electrode of each layer was formed by gradually increasing the inner mask at the time of formation so that each electrode was exposed concentrically on the inner periphery.

The inner diameter of each transparent electrode gradually increases with distance from the substrate. For example, the transparent electrode closest to the substrate is exposed in a ring shape on the innermost side, and a voltage can be applied from this portion. . The transparent electrode above it is exposed in a ring shape with a slightly larger diameter.
If this exposed portion is provided with a ring-shaped metal portion with a width (for example, 90%) slightly narrower than the radial width to increase the conductivity and mechanical strength, the manufacturing cost will increase slightly, but in terms of performance Particularly preferred. As another method, the reflective electrode serving as the electrode and the transparent electrode are each provided with a radial lead-out electrode at the innermost circumference, and the lead-out electrode reaches the innermost circumference of the disk. In order to connect to different electrodes on the shaft, they may be connected to a plurality of electrodes on the end face of the disk center hole. It is also preferable to reduce the sheet resistance by forming a metal layer on the lead electrode and a transparent electrode on the circumference of 1 to 5 mm in the radial direction just outside the lead electrode. When the disk is placed, each electrode of the disk receiving portion on the rotating shaft comes into contact with the extraction electrode on the disk side or the electrode connected thereto. When contacting the electrodes on the end face of the center hole, the electrodes to be connected need to be aligned with each other in the disk rotation direction by a combination of convex portions and concave portions. The method of connecting from the concentric transparent electrode to the concentric metal electrode provided on the surface of the bonded substrate through the bonded substrate penetrating electrode and connecting it to the concentric circular electrode is preferable in that alignment is not required. However, even in the case of a radial transparent electrode, if the position of the radial electrode is aligned with the position of the substrate through electrode of the bonded substrate, the electrodes on the surface side of the bonded substrate (side facing the outside after bonding) are concentric. When the disc is set in the drive device, alignment is not necessary.

  As shown in FIG. 2, metal pins (thin metal cylinders or metal wires) penetrate through the inner peripheral portion of the laminated substrate like a printed circuit board, and concentric metal layers corresponding to the number of transparent electrodes on both sides. Are formed, and metal pins connect corresponding electrodes on the front surface and the back surface. The side to be attached to the substrate having the recording layer is solder-plated on the metal wiring on the surface of a normal printed circuit board. In this case, a conductive adhesive tape layer or a low melting point metal such as In or an alloy layer is formed. The conductive pressure-sensitive adhesive tape is obtained by mixing a conductive material such as metal powder, carbon powder, and metal mesh with at least one of the base film and the pressure-sensitive adhesive. Since In or a low melting point alloy is soft at a low melting point as used for pressure bonding of the face plate of the image pickup tube, when it is pressed against the substrate having the recording layer, it deforms and adheres to the transparent electrode. If the temperature is raised to around 100 degrees and the pressure bonding is performed, the pressure becomes even softer and the pressure bonding becomes easier. With such a disk structure, electrical connection can be reliably and uniformly performed with high reproducibility and reliability. Each of the concentric portions of the transparent electrode drawn out to the inner periphery of the disk and the concentric electrodes on the surface of the bonded substrate does not necessarily have to be a circle (ring), and may be divided into a plurality in the circumferential direction. In this case, the two electrodes corresponding to the pair of transparent electrodes sandwiching the recording layer are aligned inward and outward as shown in FIG. 22 so that a predetermined voltage is applied regardless of how the disk is mounted on the rotating shaft. Arranged.

  This disk is mounted in a drive device similar to a conventional optical disk drive device such as a DVD-RAM. However, only a mechanism for transmitting voltage to the disk is added. In this embodiment, the voltage transmission mechanism is a ball bearing or a slip ring. The slip ring is a combination of a ring-shaped metal on the rotating shaft side and a strip-shaped metal called a stationary brush. Conductive grease was used for the ball bearing. The voltage transmission mechanism is provided on the disk side of the disk rotation motor, on the outside (periphery) of the disk rotation motor, or on the side opposite to the disk of the disk rotation motor.

  As shown in FIG. 3, there is a lead wire 21 from the voltage transmission mechanism to the tip of the rotary shaft inside or on the surface of the disc rotating shaft 31, and the lead passes inside the inner diameter of the disc before the tip of the rotating shaft. It is connected to the electrode 25 corresponding to the number of electrodes of the disk at the tip of the rotating shaft. In the figure, this electrode is provided on the side surface of the tip of the rotating shaft that is perpendicular to the center line of the rotating shaft at the tip of the rotating shaft, cylindrical, or conical, and is pin-shaped, concentric, concentric It may be cylindrical or concentric truncated cone. On the drive device side, there is a disk retainer 23 which is fixed to the drive device by a spring through a ball bearing and rotates together with the rotation shaft by pressing the disk when rotating the disk. The disk retainer is a small disk and an outer ring. It consists of. The small disk and the ring are connected to each other at three positions of 120 degrees by different spring materials. The small disc has a concentric electrode or pin electrode corresponding to the pin electrode or concentric electrode at the top of the rotating shaft, and the ring is formed with a pin electrode corresponding to the concentric electrode on the substrate surface at the inner periphery of the disk. The small disk and the ring may be integrated. When not integrated, the corresponding electrodes are connected by a conducting wire passing through one of the above-mentioned three springs of 120 degrees.

  Electric power was supplied to each electric wire of the disk rotating shaft from the circuit board of the recording apparatus by a voltage transmission mechanism of a combination of a plurality of brushes and rings (commonly called slip rings). The rotating shaft diameter (outer diameter of the ring) of the brush (which may be a simple strip-shaped metal plate or a large number of aggregates thereof) and the ring portion was 3 mm. From each ring, the wiring from each ring goes up to the disk receiving part in the rotating shaft. Six separated electric wires are connected to the electrode of the disk receiver so as to be able to handle a multilayer disk of up to five layers through the vicinity of the surface of the rotating shaft of the disk rotation motor. When the disc is inserted into the drive device, the disc presser is lowered from the top with respect to the disc placed on the disc placement portion 24. First, the ring portion presses the inner periphery of the disc. At times, the corresponding electrodes come into contact. Next, the small disk slightly lifted by the three springs of 120 degrees is pressed against the top of the rotating shaft, and the corresponding electrodes come into contact with each other. As a result, the stationary electrode in the drive and each electrode on the disk are connected via the disk presser. The small disk may also have a ring shape with a hole in the center.

  In the case of a brush and a ring, if the rotational axis of the portion is made as thin as possible, the diameter is 5 mm or less, more preferably 3 mm or less, and the linear velocity is reduced, wear can be suppressed and the life can be extended. The diameter is preferably from 0.5 mm to 5 mm, particularly preferably from 1 mm to 3 mm. If it is too thin, the mechanical strength is insufficient, and the wear of the brush is rather fast. If it is too thick, the lifetime will be less than one year due to wear. In this case, it is also preferable to have a structure in which the upper and lower portions (left and right in the case of horizontal placement) of the portion are supported by bearings so that no force other than the rotational direction is applied to the portion. The brushes may be independent for each electrode, but here, six brushes are combined into one spring plate. In this way, the operation can be stably performed without mutual interference even when the number of electrodes is about 50.

  A ball bearing may be used instead of the combination of a brush and a ring. However, downsizing becomes difficult. The ball bearing was filled with grease made conductive by mixing fine powders of metal such as carbon, Au, or Ag to improve conductivity. In the case of a brush and a ring (slip ring), if the disk rotating shaft is always rotating while the recording and / or reproducing device is in a normal operation state, a large amount of wear powder is generated due to wear. It has no lifetime. Therefore, it is preferable that the ring is slid only when erasing / coloring is necessary and the ring and the brush are separated from each other. Since the color is slightly colored even at a voltage of 0, the ring and the brush can be separated at least during reading or recording. When a disc is inserted into the drive device, a brush or a group of brushes (for example, an insulating base sheet such as polyethylene terephthalate or a plurality of long strips (thin tapes) of metal arranged at predetermined intervals) is longitudinal. When the disc is fixed in place and needs to be recorded / reproduced, place at least one of the brush group and ring group toward the other party. It is better to move it to contact. Similarly, the brush group and the ring group are brought into contact with each other only when erasing and coloring are necessary. When a disk drive part including a motor and an optical head is drawn out and can be pulled out as in a notebook personal computer CD-ROM device, when the drawer is pushed in, the ring may push the group of brushes and contact.

  In this way, when the brush group and the ring group are attached to or separated from each other, it is preferable to use one or two rings at the end for position detection so that the position of each ring corresponding to each brush is properly aligned. . Here, as shown in the block diagram of FIG. 18, a method of applying servo by detecting the electrostatic capacitance between the brush and the ring is used, but other known detection methods may be used. When the misalignment is detected, the relative position is corrected by applying a servo that moves the brush in a direction perpendicular to the disk surface.

  In addition, the life of the brush group can be extended by providing a control mechanism for changing the contact position with the ring so that the brush group is gradually drawn out or pulled in as time passes. As shown in FIG. 7, the brush group 73 has a tape shape (or belt shape), and is wound very slowly or intermittently from one shaft 71 to the other shaft 72 like a tape of a tape recorder. If the contact position with the ring 70 at the position corresponding to the magnetic head of the tape recorder is changed, the life can be further extended. Reference numeral 74 denotes a roller (capstan) for pressing the tape-shaped brush group against the cylindrically stacked ring. Thus, when changing the contact position with the ring on the brush side, the ring is made of a metal that is not easily worn, such as tungsten or a known wear-resistant metal, and the brush is a soft or easily worn metal or semiconductor such as silver. It is desirable to form from a material such as copper, aluminum or the like. Further, if the surface of the tape base material is made sticky so that the wear powder adheres to the tape, the spread of the wear powder in the recording / reproducing apparatus can be suppressed. The tape may be formed by alternately bonding elongated electrodes and elongated insulating materials without using a base material. One winding shaft 72 has another slip ring, and a voltage is supplied through the brush group 75. The brush group 75 may be brought into contact with one of the capstans 74 instead of the winding shaft. In this case, it is assumed that the electrode is exposed on both sides as in the above-described laminated type, and a laminated cylindrical electrode is provided on the capstan. In order to avoid the adverse effect of abrasion powder on the rotating shaft, it is better to use a capstan located behind the tape feed. An electric wire 76 is connected to each brush (long strip electrode), and a voltage is applied from a pulse power source. It is more preferable that at least one of the brush and the ring has very fine holes and is impregnated with a lubricant.

  Such a combination of a brush and a ring is used when another voltage application optical disk is used, or when a voltage transmission mechanism is provided at a position opposite to the disk with respect to the rotary motor in the configuration of FIG. When provided, the recording / reproducing apparatus having another configuration, for example, a combination of a brush and a ring, a rotating shaft, a disk receiving portion, and an apparatus for transmitting a voltage to the disk has an effect of extending the life. That is, the voltage transmission mechanism may be on the disk side of the disk rotation motor or on the opposite side. In the case of the opposite side as shown in FIG. 21, a space is required in the lower part of the motor.

  To summarize the main points of the recording medium part, the recording medium is an information recording medium for recording information by light irradiation, and is a layer of a material whose light absorption or reflection spectrum changes at least by applying a voltage on a substrate. Two or more unit structures with single or multiple layers sandwiched between transparent or semi-transparent electrodes are stacked, and the ends of these transparent electrodes or electrodes extending from the transparent electrodes are concentric or radial on the inner periphery of the disk It is formed in such a manner that another substrate is further stuck thereon. A part of at least one of the substrates is provided with a plurality of metal pins penetrating the substrate or bypassing the vicinity of the central hole of the substrate and reaching the opposite surface, and concentric electrodes are provided on the surface side of the substrate. good. Each of the concentric electrodes may not be continuous, and a plurality of electrodes may be arranged on each circle. The plurality of electrodes may not correspond to the same potential, but may correspond to different transparent electrodes in the recording area. It is further preferable to reinforce by applying or attaching a material containing metal or carbon fine particles to the electrode of the mating substrate to which the electrode is to be bonded or the electrode on the drive device side.

  As a first modification of the present embodiment, as shown in FIG. 4, information is recorded in advance on the recording medium in the form of irregularities, or information is recorded by applying energy such as light to the recording medium. A recording apparatus, which is a concentric or concentric cylinder corresponding to the number of electrodes of the disk at the tip of the rotating shaft, the conducting wire 40 extending from the spring built-in pin electrode 41 disposed on the concentric circle of the disk receiver toward the tip of the rotating shaft. Means for connecting to a cylindrical or frustoconical electrode 49, means for contacting a plurality of concentric cylindrical or concentric frustoconical electrodes corresponding to the number of electrodes of the disc, and rotating the disc It is also possible to use an information recording apparatus comprising disk pressing means 44 that presses the disk and rotates together with the rotating shaft. The coloring control method and recording method are the same as in the above example. In this case, the voltage is transmitted to the stationary part of the drive—the vicinity of the disk presser—the lower surface of the disk.

  Through the inside of the disk receiver, six separate electric wires (only three of them are drawn) 40 are connected to the electrodes of the disk receiver so as to be able to handle a multilayer disk of up to five layers. Each electric wire is connected to a pin electrode located on each circumference of the concentric circles. Electric power was supplied to each electric wire of the disk rotating shaft from the circuit board of the recording apparatus by a voltage transmission mechanism of a combination of a plurality of brushes and rings (commonly called slip rings). The rotating shaft diameter (outer diameter of the ring) of the brush (strip-shaped metal plate or a large number of aggregates thereof) and the ring portion was 3 mm. From each ring, the wiring from each ring is lowered toward the disk receiving portion in the rotating shaft. The details of the brush and the ring are the same as described above, and the brush may be a winding method. Each of the concentric electrodes of the disk is not continuous, and a plurality of electrodes may be arranged on each circle. The electrode may be a wedge-shaped metal piece. The electrode may be formed by applying or pasting a material containing metal or carbon fine particles.

  As a modification of this embodiment, as shown in FIG. 11, a voltage transmission mechanism of a combination of a plurality of brushes and rings is provided below the motor that drives the rotating shaft, and power is supplied from the circuit board of the recording apparatus. You may make it do.

  As shown in FIG. 8, the structure of the disk receiving portion is concentrically formed among a plurality of pin electrodes including springs located on a concentric circle 81 provided on the disk receiving 80 and each pin electrode of the disk receiving. Assume that each of the four conducting wires is gathered and has a conducting wire toward the rotary shaft tip 83. The number of pin electrodes on one concentric circle may be four or less, for example, one.

  Further, as another modification of the present embodiment, as shown in FIG. An information recording apparatus for recording information by providing information on the recording medium in the form of projections or depressions in advance, or by applying energy such as light to the recording medium, and a spring 68 through a rotation holding mechanism 62 such as a ball bearing, The disk pressing means 63 is fixed to the drive device by the disk, and rotates when the disk is rotated to hold the disk and rotate together with the rotating shaft. The disk pressing means is electrically connected to the stationary part of the drive device through the rotation holding mechanism such as the ball bearing. A concentric electrode corresponding to each part of a rotation holding mechanism such as a ball bearing and the like, and a pin with a built-in spring corresponding to the concentric electrode 65 of the disk provided in the disk pressing means. Electrical connection means (conductive wire) 58, and when the disc is inserted into the drive device, The click presser is moved toward the disk, an information recording apparatus having a means for controlling so as to be in contact with the concentric electrodes of the disk. The coloring control method, recording method, and the like are the same as in the above embodiment. Each of the concentric electrodes may not be continuous, and a plurality of electrodes may be arranged on each circle. The electrode may be a wedge-shaped metal piece. The electrode may be coated with a material containing metal or carbon fine particles.

  In this case, the voltage is transmitted to the stationary part of the drive device—the disk retainer—the upper surface of the disk (that is, the surface opposite to the disk rotation motor). Therefore, the substrate on which the film is formed becomes the motor side, that is, the disk receiving side, and the optical head is usually arranged on the same side as the disk rotation motor with respect to the disk. In this case, recording is performed directly over the substrate, not through the adhesive layer.・ I will play it. When all layers are formed by sputtering or vacuum deposition and the groove shape is inherited up to the upper layer, this is less likely to be affected by uneven thickness of the adhesive, which is desirable.

  In the case of organic materials, the uneven pattern of the substrate is buried when applied, so that the film is formed on the substrate on the disk holding side, and the metal pin that penetrates the substrate is not brought into contact with the transparent electrode of the opposite substrate or its extension electrode. It is necessary to attach a transparent electrode or an extension electrode thereof to the vicinity of the penetrating metal pin and connect the electrode on the disk and the pin electrode with a conductive paste or the like.

  In the case of an electrode arrangement in which concentric circles are further divided into arcs as shown in FIG. 22, the transparent electrode is drawn to indicate which electrode on the disk mounting portion or disk pressing portion corresponds to which electrode on the disk. It is desirable that detection is performed on the drive device side by the difference in resistance value, capacitance, and focus error signal depending on the length.

  The brush group and the ring group may be located at the position shown in FIG. In this case, the cylinder of the ring group is fixed to the arm and stationary, and the brush group rotates together with the rotating shaft. The voltage is transmitted to the stationary part of the drive device—a part of the ring group of the disk presser—the brush group—the lower surface of the disk. Even when the voltage transmission mechanism is provided at the lower part of the motor shown in FIGS. 11 and 21, it is possible to provide a ring group on the stationary side and a brush group on the rotating side as shown in FIG.

  The inner periphery of the disk may have a single plate structure. In this case, the disk holder or the electrode of the disk receiver is brought into contact with the transparent electrode layer on the disk or a reinforced one thereof. When a thick substrate having a thickness of 1.0 mm to 1.2 mm is used like a Blu-ray disc, there is no problem in strength even if there is no cover layer having a thickness of about 0.1 mm in the inner peripheral portion. The 0.1 mm cover layer can also be regarded as the other substrate.

  The electrical connection from the stationary part to the rotating part of the drive device may be a light emitting diode or a combination of a laser and a light receiving element, or a combination of coils in addition to the contact method as described above. However, when the current cannot be sufficiently supplied, it is necessary to arrange a plurality of sets, and occupy a certain volume in the drive device.

  In the present invention, a portion that is a groove in the concave portion of the substrate is called a groove. The land between the grooves is called a land. When light is incident on the film through the substrate, the groove looks convex when viewed from the incident side. For this reason, even in a method in which light is incident from the side opposite to the substrate, the convex side when viewed from the incident side is sometimes called a groove. This part is a convex part when attention is paid only to the substrate, and is a land part between the grooves, so that the terminology is opposite to the definition of the present invention. In the case of so-called in-groove recording, in which recording is performed on only one of the land and the groove, the recording characteristics are better when the light incidence is from the substrate side or from the opposite side of the substrate and the recording is performed on the convex portion when viewed from the light incidence side In many cases, it is good, but since it is not a large difference, it may be recorded in the recess as viewed from the light incident side.

  The standard recording / reproducing laser beam is incident from the side of the laminated substrate. A metal reflection layer may be provided on the uppermost surface without providing a metal reflection layer on the substrate surface, and if necessary, a metal reflection layer may be provided to allow laser light to enter from the substrate side.

  Although all the embodiments have been described for the disk, a stationary recording medium that does not rotate may be used. In that case, the position of the laser beam is changed. The concentric stepped electrode exposure is a linear stepped exposure.

  An apparatus using a stationary recording medium is an information recording apparatus for recording information by giving information in a concave-convex shape in advance to the recording medium or applying energy such as light to the recording medium, and the recording medium is at least Two or more sets of electrochromic material layers between two transparent or semi-transparent electrodes are stacked, the recording medium is stationary, and the recording medium side electrode and power supply are located inside the insulator cover. The information recording apparatus may be characterized by being connected by a connector incorporating a plurality of metal contacts.

(Record / Erase / Play)
Information was recorded / reproduced on the recording medium. The operation of this information recording / reproducing will be described below. First, as a motor control method for recording / reproducing, a method employing a ZCLV (Zoned Constant Linear Ve1ocity) method in which the number of revolutions of the disk is changed for each zone for recording / reproducing will be described. The ZCLV method was optimal in order to obtain uniform effects of preheating and preliminary irradiation when using a multi-laser beam, which will be described in detail later. For recording, the original digital signal was modulated by 8-16, and one recording mark was recorded in a multi-pulse recording waveform consisting of a larger number of pulses as a longer mark.

(Multi-beam recording)
In this example, the optical axis including the installation angle of the laser is tilted so that each light spot on which the multi-beams are focused has a focal position on a different layer, or the effective laser light emission position is different. Add. Accordingly, normal recording may be performed on each recording medium. The multi-beam light source may be an individual laser or an array laser, but an array laser is particularly preferable for four or more beams. It is desirable to focus any one of the beams on a layer having a well-defined groove or pit shape as a reference beam, and then determine the relative position of each beam.

  In the case of a conventional phase change write-once type four-layer recording medium with four-beam simultaneous recording, the layer interval is large to prevent interlayer crosstalk, so it is necessary to tilt the optical axis greatly, and it is difficult to collect light due to aberrations, and the lens is attached to the disc. The problem of colliding occurs. For example, in the case of a laser array with a beam spacing of 100 μm, the tilt angle becomes 1/5 when the layer spacing is 20 μm. In addition, it is extremely difficult to make the thickness of each spacer layer determining the layer interval uniform with an accuracy of 100 nm or less, which causes a focus shift. Adding a step corresponding to the layer spacing to the emission surface of each chip is effective in making the disk surface and the laser beam perpendicular to each other, but it is difficult to make the step large and highly accurate. Further, the recording sensitivity is low due to light absorption of each layer, and there is a possibility that the recording speed will be slow due to insufficient power.

  However, in the case of the voltage layer selection type multi-layer recording medium, the above-mentioned problems of the phase change recording medium can be solved. First, if the layer spacing is 0.1 μm (100 nm) or less, the tilt angle is sufficiently small with respect to the irradiation beam spacing of about 10 μm. However, the layer period is about 300 nm here.

  In this embodiment, a normal one-chip array laser is used. However, it is also preferable that each laser chip of the array laser is cut off and bonded with a gap between the chips on the silicon substrate. The light spot interval (irradiation beam interval) is about 1/8 of the beam interval depending on the NA ratio between the collimator lens (NA about 0.1) and the focusing (condensing) lens. However, it is possible to widen the spot interval on the disk, to reduce the incident inclination of the beam, and to obtain the preheating coloring time by the following mechanism. However, if the distance is too wide, there is a problem that when the light is condensed by one lens, aberrations appear in the beams at both ends. Assuming that the number of beams entering one lens is 5, in order to keep the aberration of the beams at both ends sufficiently small, it is particularly preferable that the NA is 0.85 or less with an outgoing beam interval of 50 μm or less. In the vicinity of NA 0.6, 70 μm or less is particularly preferable. If aberrations appear due to the influence of oblique incidence by narrowing the beam interval, it is preferable to place a stepped glass or quartz at the laser emission part to provide an optical path difference. In the case of the present invention, the thickness of one layer is 100 times larger, resulting in a step of about 40 μm, which facilitates high-precision machining.

  The voltage layer selection type multi-layer recording medium can record even with little light absorption, so the layer corresponding to the number of beams may be colored and recorded. However, in the case of higher speed recording, as shown in FIG. Control as follows. In FIG. 9, 91 is an electrochromic material layer, 92 is a transparent electrode, and 93 and 94 are substrates. First, the first deepest layer corresponding to the first beam that hits the disc is turned into a light colored state by applying a voltage so that autofocus and tracking are possible, so that the recording state does not change even when laser light is irradiated. Keep it. When it is difficult to prevent the recording state from changing, a dummy layer that does not perform recording may be used. In this case, the most advanced beam is not subjected to power modulation and dedicated to continuous heating. The layers up to the number of beams from this layer are not perfectly focused, but exist in a range where the optical power density is high, so apply a pulse voltage of a higher voltage in advance than normal coloring or A low voltage application is started almost simultaneously with or slightly behind the layer, slightly colored, and pre-irradiated by irradiation with the preceding beam. The recording medium is accelerated in coloration by preliminary irradiation, and light absorption rapidly increases. Therefore, when the second layer is irradiated from the back by the second beam, a sufficient amount of absorption is obtained. Since the recording track is spiral, if the second beam is arranged so that it hits the same place on the disc after several revolutions of the disc after the first beam is irradiated, it takes a time in ms until it is sufficiently colored after preliminary irradiation. The second beam is irradiated even in a sufficiently colored state. If waiting for 3 revolutions, the waiting time is about 0.1 seconds (more precisely, the reciprocal of the number of revolutions per second expressed in rps × 3). Sufficient coloring is achieved with a single digit acceleration. That is, the effect is great if the light spot position of the next beam is within plus or minus number of beams × 3 tracks with respect to the light spot position of the preceding beam with the outer peripheral direction as the positive direction.

  When waiting for a large number of rotations, the effect of preliminary irradiation is lost, the beam spot interval becomes too wide, the number of lasers per wafer decreases, and the laser price increases. However, in the case of a 100 μm pitch laser array, there is a possibility that the spot interval is up to 20 μm. For example, if the track pitch is about 0.6 μm, there is a possibility that 33 tracks are separated, that is, until 33 waits. The same applies to the third and fourth beams. In this way, recording / reproduction is performed in a state where only the target layer is sufficiently colored. Recording was performed by losing the coloring function by heat only at the place irradiated with the high power laser.

  In addition to the effect of preliminary irradiation, it is possible to use a delay in coloring or decoloring from the inner periphery to the outer periphery due to the surface resistance of the transparent electrode. In this case, it takes about 1 second for the coloring and decoloring front to move from the innermost circumference to the outermost circumference of a 120 mm diameter disk. For example, when the rotational speed is 30 rps, The erasing front will proceed. In order to give a difference between coloring and transparency between adjacent layers at a point on a certain radius with the maximum spot interval of 20 μm, it is only necessary to start applying a coloring voltage at intervals of 1/50 seconds. When the number of layers is greater than the number of beams, recording is performed in the same manner by jumping the layers by the number of beams in order to record / reproduce to other layers.

  The mechanism by which coloring is accelerated by preheating and / or preliminary irradiation will be described in a little more detail. For that purpose, it is necessary to first describe the coloring mechanism. Each recording layer is basically composed of two or three layers, and as shown in FIG. 15, the solid electrolyte layer and the electrochromic material layer play the main roles. The solid electrolyte layer is formed by solidifying what was initially an electrolytic solution, and its operation is easy to consider when considered with a liquid electrolyte.

  In the electrochromic layer, the polyethylenedioxythiophene molecules are in some state of relatively high molecular weight polystyrene sulfonic acid (PSS) molecules, corresponding to the positively charged Li ionized in the electrolyte. Polystyrene sulfonic acid molecules take electrons from polyethylene dioxythiophene molecules and are negatively charged. A positive charge is generated in polyethylenedioxythiophene, and polarons and bipolarons are formed. A molecule in which polaron or bipolaron is formed has almost no light absorption in the visible region. When a voltage is applied with the electrode on the electrolyte side positive and the electrode on the electrochromic layer side negative, Li ions in the electrolyte move to the electrochromic layer side and collect on the surface of the layer. Some Li ions penetrate into the electrochromic layer. Since electrons are injected from the electrode on the electrochromic layer side, the electron concentration in the electrochromic material layer is increased, and the electrons are combined with the positive charge of the polythiophene dioxythiophene molecule. This causes coloration. Some of the electrons trapped in the PSS are attracted by Li ions and exit in the direction of the electrolyte.

  When light is irradiated in this coloring process to generate photocarriers and the temperature of the electrochromic layer increases, the conductivity of the hopping conductivity increases. Then, the electron injection is greatly accelerated, and electrons are generated as photocarriers, so that coloring is greatly promoted. This phenomenon is used for preliminary irradiation with a preceding beam. As long as the material is known to have hopping conduction, semiconducting conduction, or photoconductivity, the same effects can be obtained with materials other than those described in this embodiment. Many inorganic electrochromic materials are semiconducting and also have photoconductivity.

  Even when the color change rate is not sufficiently improved due to the temperature rise and the conductivity rise due to the photocarrier, the change in the absorption edge due to the temperature rise can be used as another preliminary irradiation effect. Both effects may be used. Usually, when the temperature rises, the organic polymer does not maintain the planarity of the molecule, and in many cases, the three-dimensional deformation occurs on the time average and the light absorption edge moves in many cases. This effect also speeds up coloring or decoloring due to the preheating effect. The change in the absorption edge due to the temperature rise is more often caused in the visible range when the transmittance increases. This is because the probability of existing in the ground state is decreased, the flatness of the polymer molecule is lost and the absorption is reduced, or the number of molecules whose absorption is reduced by emitting electrons is larger than in the reverse case. If the effect of increasing the transmittance while the temperature is higher is greater than other effects, place the pre-illuminated beam on the most light incident side and focus the subsequent beams sequentially on the back layer. Is good. In such an arrangement, it is possible to use the effect that the transmittance of the portion of the recording mark is increased by recording and the average amount of light transmitted to the inner layer is increased. Since the various processes described above are orders of magnitude faster than the movement of Li ions, coloring / decoloring can be greatly speeded up. In addition to preheating, speeding up of coloring due to photochemistry or physical effects may be used.

  On the other hand, when using a recording medium having a characteristic in which decoloration is accelerated by heating, the first beam is focused on the foremost layer, and one layer at the back begins to be decolored. Even when erasing starts, the color is still dark when the second beam hits, so recording and playback are easy, but when the third beam hits, the color is erased so as not to interfere with recording and playback of the two layers behind. ing. For example, a phenomenon in which absorption is attenuated by absorption saturation can be used.

  In order to obtain the preheating effect described above, the array laser generates a plurality of substantially parallel laser beams from a plurality of sources (lasers) arranged substantially on the same straight line, but separates the laser elements and widens the intervals. However, it is preferable to arrange them in a straight line by using a cleavage plane of a silicon single crystal.

  After irradiating the first layer with the first light spot from the first laser beam and irradiating the first layer with the first light spot, a second light incident side adjacent to the first layer is provided. Information is recorded or reproduced by positioning the light spot so that the second light spot is irradiated to the layer. A light spot formed on each layer of a multilayer recording medium from a plurality of laser beams can be obtained by positioning or controlling adjacent beams on the same track in the radial direction of the substrate or within plus or minus number of beams × 3 tracks. Although an irradiation effect was obtained, if there was a position shift beyond that, the preliminary irradiation effect was insufficient for recording and reproduction without the influence of other layers. As long as it is within one plus or minus track, there is an advantage that writing can be started from almost the innermost track or the outermost track at the same time.

  In this way, arranging a large number of laser beam spots on the same track or adjacent tracks in the circumferential direction of the disk makes it easy to check the address, and any beam is off the outermost or innermost track. It is also preferable in that there is no. It is necessary to detect a positional shift by providing means for detecting a tracking error signal or a track address signal with at least two laser beams close to both ends of the plurality of laser beams.

  The above multi-layer recording medium is a preheating / preliminary irradiation beam that does not record information in a predetermined cycle but is colored by voltage application and can increase the reflectance so that the recording state is not destroyed in the layer irradiated with the preheating light spot. It is preferable to have a dedicated focus / tracking layer.

  In the optical head mounted on the recording apparatus, a semiconductor laser array having an optical wavelength of 660 nm is used as a laser beam for information recording. The laser beam is narrowed down onto the recording layer of the optical disk by an objective lens having a lens NA of 0.65, and information is recorded by irradiating the laser beam. Instead of the array laser, two or more individual laser beams may be guided to a predetermined position.

  Such promotion of coloring / decoloring by the preceding beam is effective not only in the case of parallel high-speed recording / reproduction, but also in the case where it is necessary to start recording or reading in a short time after layer selection. It is conceivable that the preceding beam and the recording / reproducing beam are used for two beams, or one beam is used for preceding irradiation for 1 to 3 rotations of the disk, and recording or reading is performed for the next rotation. Subsequently, when the voltage is reversed and the DC light is irradiated once, the color erasing can be promoted.

In the recording medium of this example, a contrast ratio of light reflectance of about 2: 1 was obtained between the recording mark and the other portions. If the contrast ratio is less than this, the fluctuation due to the noise of the reproduction signal exceeds 9% of the upper limit value, which is outside the range of the practical reproduction signal quality. If SiO ₂ is contained in the transparent electrode to be (SiO ₂ ) ₄₀ (In ₂ O ₃ ) ₅₅ (SnO ₂ ) ₅ , the refractive index is lowered and optically advantageous, and the contrast ratio is 2.5: 1. It was done above.

  When recording is performed by amorphization of an electrochromic material layer or a separately provided chalcogenide material layer, erasing is performed by lowering the applied voltage and continuously irradiating laser light to crystallize the amorphous region. Erasing may also be performed by irradiating a pulse laser and repeating a pulse wider than any recording pulse.

  The recorded information is also reproduced using the optical head. The layer to be reproduced is colored by preheating in the same manner as in recording, a laser beam is irradiated onto the recorded mark, and the reflected light from the mark and the part other than the mark is detected, thereby obtaining a reproduction signal.

  In the case of multiple beams, the focal position of each beam does not necessarily have to be on a separate layer. For example, two beams may be recorded / reproduced on the same layer. The method using multiple beams of this embodiment is also effective for a voltage layer selection type optical disk apparatus other than the apparatus structure of the present invention.

  In the case of a plurality of beams, the reproduction signal of each beam is restored to a single time-series signal by multiplexing means (combining means) if necessary. If each of the plurality of readout beams is irradiated with a high-speed pulse in time series, this time series can be facilitated. The amplitude of the reproduction signal is increased by a preamplifier circuit, and the 8-16 demodulator converts it into 8-bit information every 16 bits. With the above operation, the reproduction of the recorded mark is completed. When mark edge recording is performed under the above conditions, the mark length of the 3T mark that is the shortest mark is about 0.4 μm. The recording signal includes repeated dummy data of 4T mark and 4T space at the start and end of the information signal. VFO is also included in the start end. Of course, signals other than 8-16 modulation can be used as the signal modulation method.

1 is a cross-sectional view of an information recording medium according to an embodiment of the present invention. The figure which shows the cross-section of the multilayer disc of one Example of this invention. The figure which shows the cross-sectional structure in the surface which passes along the rotating shaft centerline near the disc attachment part of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows the cross-sectional structure in the surface which passes along the rotating shaft centerline near the disc attachment part of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows the method of sequential intermittent voltage application to each layer from the single power supply of the multilayer disk of this invention. The figure which shows the cross-sectional structure in the surface which passes along the rotating shaft centerline near the disc attachment part of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows the mechanism which moves the contact surface of the brush of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows arrangement | positioning of the spring loaded pin electrode of the disc receiving part of the multilayer disc recording / reproducing apparatus of this invention. The figure which shows the structure which records / reproduces to the multilayer disk of this invention at high speed with a multi laser beam. 1 is a cross-sectional view of an information recording medium according to an embodiment of the present invention. The figure which shows the cross-sectional structure in the surface which passes along the rotating shaft centerline near the disc attachment part of the multilayer disc recording / reproducing apparatus of one Example of this invention. The side view of the voltage transmission ring group and brush group which have the mechanism which moves the contact position of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows the structure of the multilayer disc recording medium and recording / reproducing apparatus of one Example of this invention. The figure which shows the structure of the switching circuit which applies a voltage to each layer of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows the coloring and decoloring principle of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows the pulse voltage applied to the layer which writes from the coloring / decoloring switching circuit of the multilayer disc recording / reproducing apparatus of one Example of this invention. FIG. 3 is a detailed view showing a spiral groove, groove wobbling and recording status of the multilayer disk recording / reproducing apparatus according to one embodiment of the present invention. The figure which shows the structure of the position shift correction circuit of the mechanism which moves the contact position of the ring group and brush group of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows the principle which can read the structure of the cross section along the pit part of the multilayer disc recording medium of one Example of this invention, or the recording track of a ROM disc, and the information of a pit arrangement | sequence. The figure which shows the cross-sectional structure in the surface which passes along the rotating shaft centerline near the disc attachment part of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows the cross-sectional structure in the surface which passes along the rotating shaft centerline near the disc attachment part of the multilayer disc recording / reproducing apparatus of one Example of this invention. The figure which shows one example of arrangement | positioning of the transparent electrode drawer | drawing-out part of the inner peripheral part of the multilayer disc medium of one Example of this invention.

Explanation of symbols

1: Substrate 2: Reflective layer 3: Transparent electrode 4: Electrochromic material layer 5: Solid electrolyte layer 6: Protective layer 7: Transparent electrode 11: Substrate 12: Transparent electrode layer 13: Conductive material 14: Bonded substrate 15: Concentric circle Electrode 16: Metal penetrating pin 18: Conductor 19: Spring built-in metal pin 20 arranged on the disk retainer 20: Metal penetrating metal pin 21: Conductor 22 along the rotation axis 22: Concentric electrode of the disk retainer 23: Disk retainer 24: Disk receiver 25 : Spring-loaded electrode 26 at the tip of the rotating shaft 26: Concentric electrode 27 of the disk: Arm 28 that supports the disk presser: Ball bearing 29: Each transparent electrode 30: Connection portion 31: Rotating shaft 39: Rotating shaft 40: Conductor 41: Disk receiving Spring loaded pin electrode 42: Transparent electrode 43: Conductive material 44: Disc holder 45: Disc through metal pin 46: D Disc concentric electrode 47: Brush group 48, 48 ': Disc receiver 49: Cylindrical slip ring ring group 57: Cylindrical slip ring ring group 58: Conductive wire 59: Disc holding spring built-in pin electrode 60: Substrate through electrode 61: Rotating shaft 62: Ball bearing 63: Disc holder 64, 64 ': Disc receiver 65: Concentric electrode 66: Conductive material 67: Slip ring brush group 68: Arm 69: Transparent electrode 70: Ring group 71: Winding Shaft 72: Winding shaft 73: Tape-shaped brush group 74: Roller 75: Feeding brush group 76: Old electric wire 80: Disc receiver 81: Concentric mark or concentric electrode 82: Spring built-in pin electrode 83: Rotating shaft 91: Electrochromic Material layer 92: Transparent electrode 93: Substrate 94: Substrate 96: Substrate 97: Reflective layer 98: Transparent electrode 99: Electro Trochromic material layer 100: Solid electrolyte layer 101: Transparent electrode 105: Conductive material 106: Transparent electrode 107: Substrate through electrode 108: Spring-loaded metal electrode 109: Conductor 110: Motor 111: Cylindrical ring group 112: Brush group 113 : Rotating shaft 114: disc press 116: roller 118: brush group 119: roller 120: ring group 121: extraction electrode 122: recording layer group 123: substrate 124: transparent electrode 125: solid electrolyte layer 126: electrochromic material layer 127: Recording layer 128: Power source 129: Laser light 130: Electrochromic material layer 131: Transparent electrode 132: Pit 133: Power source 135: Concentric electrode 136: Conductive material 137: Ball bearing 138: Conductor 139: Spring-loaded metal pin electrode 140: Transparent electrode 141: rotation Brush group 142: stationary cylindrical ring group 143: disk pressing and fixing portion 144: substrate through metal pin 145: rotating shaft 146: brush group mounting rod / conducting wire passage 147: disk pressing member 148: disk receiving portion 149: drive device fixing arm Combined conductor passage 150: Disk holding attachment ring and conductor passage 151: Conductive material 152: Conductor 153: Spring loaded metal pin electrode 154: Substrate through metal pin 155: Concentric electrode 156: Brush group attachment rod / conductor passage 157: Brush group 158: Motor case 159: Disc holding member 160: Cylindrical ring group 161: Fixed ring / conducting wire passage 162: Rotating shaft 163: Transparent electrode 164: Feed line 171: Leading portion of the first transparent electrode to the inner periphery of the disc 171 ′: second lead portion 172 of the first transparent electrode: second The transparent electrode lead-out portion 172 ′ of the second transparent electrode: the second lead-out portion 173 of the second transparent electrode: the third transparent-electrode lead-out portion 173 ′: the second lead-out portion 174 of the third transparent electrode : Fourth transparent electrode lead 174 ': fourth transparent electrode second lead 175: fifth transparent electrode lead 175': fifth transparent electrode second lead 176: second 6 transparent electrode lead-out portion 176 ': sixth transparent electrode second lead-out portion 177: disc center hole

Claims (13)

A rotation axis;
A disk mounting portion fixed to the rotating shaft;
A disc holding portion that presses and fixes the disc-shaped recording medium placed on the disc placing portion, and rotates integrally with the disc-shaped recording medium;
A plurality of contact electrodes that are exposed on a disk contact surface of the disk mounting portion and that are in contact with electrodes sandwiching a recording layer of a disk-shaped recording medium mounted on the disk mounting portion;
Power supply,
An information recording apparatus comprising: a conductive path connected to the power source and supplying power to the plurality of contact electrodes. A rotation axis;
A disk mounting portion fixed to the rotating shaft;
A disc holding portion that presses and fixes the disc-shaped recording medium placed on the disc placing portion, and rotates integrally with the disc-shaped recording medium;
A plurality of contact electrodes that are exposed on a disk contact surface of the disk pressing portion and that are in contact with electrodes sandwiching a recording layer of a disk-shaped recording medium mounted on the disk mounting portion;
Power supply,
An information recording apparatus comprising: a conductive path connected to the power source and supplying power to the plurality of contact electrodes.   3. The information recording apparatus according to claim 1, wherein the plurality of contact electrodes are biased in a direction protruding from the disk contact surface.   3. The information recording apparatus according to claim 1, wherein the conductive path is installed in the rotating shaft or on the surface of the rotating shaft.   3. The information recording apparatus according to claim 1, wherein the conductive path is installed in the disc pressing portion.   6. The information recording apparatus according to claim 5, wherein the information recording apparatus has an elongated conductor that is in contact with the rotating shaft and whose contact position is movable in a longitudinal direction, and the conductor constitutes a part of the conductive path. Recording device.   3. The information recording apparatus according to claim 1, wherein the contact electrode is a pin-shaped or strip-shaped electrode, and directly or other than an electrode sandwiching a recording layer of a disk-shaped recording medium mounted on the disk mounting portion. An information recording apparatus which contacts through a conductive substance. Installing a disk-shaped recording medium having a plurality of recording layers that develop color by applying a voltage sandwiched between a pair of electrodes, on a disk mounting portion fixed to a rotating shaft;
A step of fixing the disc-shaped recording medium placed on the disc placing portion by pressing it with a disc pressing portion that rotates together with the disc-shaped recording medium;
A plurality of contact electrodes provided on a disk contact surface of the disk mounting portion or a disk contact surface of the disk pressing portion are sandwiched between a pair of electrodes that sandwich one recording layer of the plurality of recording layers. Applying a voltage in a direction in which the recording layer is colored;
And a method of selectively recording information on a recording layer sandwiched between a pair of electrodes to which the voltage is applied by irradiating the disk-shaped recording medium with light.   9. The information recording method according to claim 8, wherein the recording layer that develops color when voltage is applied includes an electrochromic material.   9. The information recording method according to claim 8, wherein a voltage in a direction in which the transmittance of the recording layer sandwiched therebetween is increased is applied to the electrode pair sandwiching the recording layer other than the recording layer for selectively recording information. An information recording method characterized by the above.   11. The information recording method according to claim 10, wherein a voltage is applied to the plurality of electrode pairs in a time-sharing manner.   9. The information recording method according to claim 8, wherein the contact electrode is a pin-shaped or strip-shaped electrode, and is directly or other conductive with an electrode sandwiching a recording layer of a disk-shaped recording medium mounted on the disk mounting portion. An information recording method comprising contacting through a substance.   A plurality of sets of a pair of transparent electrodes, an electrochromic material layer and a solid electrolyte material layer between them, and two substrates sandwiching them, one of these two substrates penetrating the substrate or the center hole of the substrate It has a conductive path made of a pin-like or strip-like conductive material that bypasses the vicinity, and they are electrically connected to any one of the transparent electrodes directly or via another conductive material, respectively. Information recording medium.

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