Abstract: A method for initializing a phase change information storage device. The method includes the steps of: providing a data storage device having a phase change data storage medium, and exposing the phase change data storage medium with a first, energy exposure for about 1 &mgr;sec or less.

Abstract: There are provided an optical recording medium and a method of manufacturing the optical recording medium. The optical recording medium has a pattern of microscopic depressions and projections molded thereon with a high fidelity of replication. The method of manufacturing the optical recording medium comprises the steps of forming a photoresist layer on a substrate; exposing a predetermined area of the photoresist layer formed on the substrate to form a plurality of trains of depressions in the photoresist layer; removing the photoresist layer between the adjoining depression trains to form a master; plating the master with a metal; separating the metal coating to form a master stamper; replicating the master stamper repeatedly an odd number of times to form a mother stamper; replicating the mother stamper to form a resin substrate; and forming at least a light-transparent layer on a surface of the resin substrate on which the mother stamper is replicated.

Abstract: Methods for forming a single-side-readable DVD having graphical information viewable from the DVD's frontside disc are provided. A first, frontside disc having a first and a second surface, with the second surface comprising program information and coated with a semi-reflective coating, is bonded to a second, backside disc having a third and a fourth surface. A first portion of the fourth surface comprises spillover program information and a second portion of the fourth surface comprises graphical information. The fourth surface is coated with a reflective coating. During DVD formation, the frontside and backside discs are adhesively bonded back to back so that the second surface of the frontside disc faces the fourth surface of the backside disc. Because the frontside disc comprises a semi-reflective coating, the graphical information on the second portion of the fourth surface of the backside disc is viewable through the frontside disc.

Abstract: There is provided a process of producing a laminate type optical disk comprising the steps of: (1) molding a pair of substrates of a transparent resin at least one of which substrates has irregularities on its one main surface; (2) forming a metal thin film on said one main surface having the irregularities, and then (3) laminating the pair of the substrates while the metal thin film is located inside and bonding the substrates by means of an adhesive which is supplied between the substrates, the process being characterized in that after the step (1), a waiting treatment is carried out in which the molded substrates are cooled to such a temperature that a difference between said temperature and a temperature of an atmosphere surrounding the substrates is not greater than 5° C. while keeping a moisture (or water) content of the substrates not larger than 0.1% by weight, and then the step (2) is carried out.

Abstract: Light-readable information-recording media are fabricated according to a method wherein the back of a production stamper is laser-scribed, diamond-scribed, etched, or marked by other means to produce an image. This production stamper is then used to form a substantially transparent substrate having information recorded on it by means of pits and lands. During the formation of the substrate, the image is transferred from the back of the stamper to the surface of the substrate. The resulting watermark may be visible under normal light conditions. Information-recording media bearing indelible watermarks according to the present invention are also disclosed.

Abstract: An optical recording medium capable of improving uniformity of thickness of a protective film and suppressing warping. The medium is configured to comprise a substrate, an optical recording film formed on the substrate, and a light transmitting protective film formed above the optical recording layer, wherein the protective film comprises a polymer sheet produced by melt casting and an adhesive layer for bonding the polymer sheet to the-optical recording layer. As the polymer sheet, a polycarbonate sheet, a cyclic polyolefin sheet, etc. can be used. As the adhesive layer, an ultraviolet curing resin, a heat curing resin, an epoxy resin-based adhesive agent or a pressure-sensitive tackiness agent may be used alone or mixed or stacked.

Abstract: An optical information medium is provided. The medium comprises a supporting substrate, an information recording layer thereon, and a light-transmitting layer thereon and a recording or reading laser beam enters the recording layer through the light-transmitting layer, and in such medium, recording/reading characteristics are improved when the beam spot of a laser beam has a small diameter and the linear velocity is high with the function of the light-transmitting layer to protect the information recording layer maintained at a sufficient level. Also provided is a medium wherein storage stability is improved.

Abstract: An optical disc prepared so that, in bonding a disc substrate to a light transmitting sheet, an air bubble incidentally trapped on a bonding surface between the disc substrate and the light transmitting sheet may be reduced in size. An apparatus used for the preparation of the optical disc includes a sheet holding mechanism (32) for holding a light transmitting sheet (19) to be bonded to a signal recording surface (14) of a disc substrate (11), a disc holding mechanism (33) for holding the disc substrate (11) on the light transmitting sheet (19) held on the sheet holding mechanism (32) so that its signal recording surface (14) will face the light transmitting sheet (19), and a thrusting mechanism (34) for thrusting the disc substrate (11) held on the sheet holding mechanism (32) onto the light transmitting sheet (19). The thrusting mechanism (34) progressively thrusts the disc substrate (11) from its center side to its outer peripheral side to drive the air bubble towards the outer peripheral side.

Abstract: An improved method and means for eliminating scratches and other mechanical surface damage from polycarbonate compact disc plastic surfaces. The method consists in applying a liquid of suitable composition to the surface of a compact disc or plastic object, allowing an average of 10 seconds or less for the solvent to soften the plastic substrate, and removing the liquid by draining and evaporation. No abrasive, filler or polishing compounds are required. Suitable liquids include those comprising a solvent for the plastic and a non-solvent diluent and a small quantity of surfactant.

Abstract: A method of making a stamper for use in a data storage disk molding process. The method includes making a first stamper including the steps of providing a stamper body having an information layer thereon. The information layer is covered with a first metal layer. A second stamper is made from the first stamper, which includes the steps of covering the first metal layer with a second metal layer to form a stamper assembly, wherein the first metal layer and the second metal layer are bonded together. The first metal layer and the second metal layer are removed from the stamper assembly to form the second stamper, wherein removal of the first metal layer and the second metal layer is nondestructive to the information layer. In one application, the first metal layer and the second metal layer are made of nickel.

Abstract: A process for producing an article having a finely uneven surface coated with a film, which has high heat resistance and which neither cracks nor peels off from a substrate, by forming a film of a sol material between a substrate and a mold in such a manner that the film is in close contact with them and applying heat to form a gelled film, which has a surface configuration that is the inversion of the surface configuration of the mold, on the surface of the substrate, wherein the sol material contains (A) R2SiX2 (R is an alkyl group and X is an alkoxyl group or halogen atom) and (B) R′SiX′3 (R′ is an aryl group or substituted aryl group and X′ is an alkoxyl group or halogen atom).

Abstract: Preventing a molded disc substrate from generating a separation pattern. To this end, a molding die 1 includes a pair of stationary die 6 and movable die 7, and an outer circumference ring 16 for molding an outer circumference end of the disc substrate 2. The outer circumference ring 16 is so mounted as to be movable along forward and backward directions in parallel with a moving direction of the movable die 7 toward the stationary die 6, and has a retaining surface 39 for retaining the outer circumference of the molded disc substrate 2.

Abstract: The present invention provides a method for manufacturing optical disk substrates whereby grooves and pits of optical disk substrates are formed highly accurately and finely, so that resulting optical disks can be of large-capacity and reduced in noise level. A coat of an organic material is provided on a substrate which is to be a master, on which a mask material is patterned as an etching mask. After the coat of the organic material is etched, the mask material is removed, whereby a master is obtained. A metallic coat is formed to the master. A metallic main body portion is integrally formed on the metallic coat. A metallic portion comprising the metallic coat and metallic main body portion is separated from the master. A metallic stamper is thus formed.

Abstract: A method for molding a thermoplastic resin by filling a molten thermoplastic resin into a mold which comprises carrying out the molding of the resin while reducing the solidification temperature of the resin surface which contacts with the mold during the step of filling the resin. According to this molding method, the state of the mold surface can be faithfully transferred to molded articles.

Abstract: An improved substrate and stamper holder and method of forming substrates are disclosed. According to a preferred embodiment of the invention, a substrate for a DVD has a moat with a capillary barrier shape. Under one embodiment, the moat has a region with an abrupt outer diameter transition. One embodiment has the outer diameter transition at approximately at a right angle relative to a registering surface of the substrate. Another embodiment of the invention provides a wider moats. The improvements reduce the likelihood of resin wicking past the moats.

Abstract: The invention intends to provide a method of manufacturing an optical disc capable of efficiently manufacturing a high quality optical disc by a consecutive product line, and to improve productivity in an injection molding step. The method is constituted by bonding two disc halves wherein a first disc half storing information therein and molded by a mold of a first injection molding unit and second disc half storing information therein, which information is different from that stored in the first disc half, and molded by a mold of a second injection molding unit are paired with and bonded to each other.

Abstract: The present invention is to provide a production method for an optical disc, capable of obtaining a good S/N ratio without deterioration of the stamper quality due to reaction with an electron attractive group contained in a resist material. The processes of forming a resist film on a substrate, patterning the resist film on the substrate by an electron beam cutting, forming a nickel alloy thin film on the patterned resist film, forming a nickel layer on the nickel alloy thin film by the electrocasting, and injection molding of a resin, using the nickel layer peeled off from the nickel alloy thin film as a stamper, are provided. The nickel alloy thin film has a composition containing Ni element as the main component as well as Ru element by less than 25% by weight.

Abstract: Provided is a method for producing optical disc substrates having a low degree of birefringence. The method has good mass-producibility, in which the pattern transferability on the substrates produced is good. In producing optical disc substrates having a diameter of from 80 to 120 mm and a thickness of from 0.5 to 0.7 mm, through injection molding or injection-compression molding, a resin for the substrates is injected and charged into the cavity of a mold at a resin filling rate of not lower than 65 cm3/sec, said resin filling rate being obtained by dividing the cavity volume (cm3) of the mold, into which the resin is charged, by the time (sec) taken from the start of resin injection through the tip of the nozzle of the injection-molding machine to the arrival of the resin at the deepest end of the cavity of the mold.

Abstract: A mould for manufacturing disc-like objects including at least two mould parts which are mutually movable between a closed position in which they bound a mould cavity, which mould cavity is connected to an injection conduit for admitting heated, plasticized plastic under pressure into said mould cavity, and an opened position in which a disc-like object can be removed. The mould also has a device for removing a central portion from a disc-like object to form a central hole present therein, which device comprises a cylindrical part which is movable in axial direction in the closed situation of the mould cavity. The mould has the feature that at least one of the two mould parts is tempered only in the middle zone of the mould cavity for tempering the inflowing plastic during the inflow thereof via the pressure line and thus during the filling of the mould cavity.

Abstract: Disclosed is an article for the optical storage of data having low birefringence prepared from a mixture of a polycarbonate and a cycloaliphatic polyester. The article may optionally have stabilization and mold release additives that retain transparency, color and processability.

Abstract: An injection-compression molding apparatus includes a stationary mold provided with a nozzle for injecting molten resin, and a movable mold driven by a servo motor. In compressing the resin, high-speed position control of the movable mold is first performed, which is then switched to speed feedback control which enables delicate regulation of clamping pressure in accordance with pressure fluctuations in the resin.

Abstract: The present invention relates to a process for producing DVD's using injection molding techniques, without the use of compression, from a polymer having a glass transition temperature (Tg) of greater than 110° C. as measured by Differential Scanning Calorimetry (DSC) at 10° C./min., an elastic modulus (G′) of less than or equal to 1000 dynes/cm2 at a temperature of 240° C., as measured by Dynamic Mechanical Spectroscopy measurements at a temperature ramp rate of 3° C./min., and a shear rate of 1 radian/sec using a parallel plate geometry (under nitrogen), and a complex viscosity (Eta*) of less than 2000 poise, as measured according to Dynamic Mechanical Spectroscopy measurements, using shear rate sweeps at 280° C., and a shear rate of 1 radian/sec using a parallel plate geometry (under nitrogen).

Abstract: An optical data recording medium in which the shape of the dye spectrum of a dye film having a thin film thickness per unit absorbance is controlled so as to enable improvements in the recording speed during high speed recording, jitter, and modulation, wherein the optical data recording medium is characterized in that 0<D/C≦100, and 80≦D/B, where D (nm) is the mean film thickness of the light-absorbing layer, C (Abs) is the maximum absorbance (based on molecular absorption) of the light-absorbing substance, B (Abs) is the maximum absorbance (based on association absorption) of the light-absorbing substance, D/C is the unit absorbance thickness based on the molecular absorption, and D/B is the unit absorbance thickness based on the association absorption.

Abstract: In order to realize a compact construction of an apparatus for producing an optical recording medium while shortening the time required for transporting a mold, there is provided an apparatus for producing an optical recording medium by curing a curable resin (102b) between a substrate (101) and a mold (103), including: a mold fixing mechanism (2) for fixing the mold (103); a transporting mechanism (1) for transporting the substrate (101) to which the curable resin (102b) has been applied to a position where the mold (103) is fixed, and placing the substrate (101) on the mold (103) such that the surface of said substrate to which the curable resin (102b) has been applied faces the mold (103); a resin curing mechanism (3) for curing the curable resin (102b) which has been sandwiched between the mold (103) and the substrate (101) by the action of the transporting mechanism (1); and a separating mechanism (4) for separating the resin (102) that has been cured by said resin curing mechanism (3), together with the

Abstract: In an optical recording medium manufacturing method for forming an optical recording medium by hardening photo curing resin between a resin plate (11) and a template in order to provide a technique for manufacturing an optical recording medium that has excellent optical properties and that is not apt to undergo failure during production, the resin plate (11) is produced by a heating step (104) for heating thermoplastic resin (10) to a predetermined temperature to be melted, a feeding step (103, 105) for feeding the melted thermoplastic resin (10) into a mold (1), and a molding step (101, 102) for molding the thermoplastic resin (10), which has been fed into the mold (1), into the resin plate (11) by compression. Since molding is performed by the mold in a low-pressure and low-temperature environment, it is possible to prevent deterioration due to oxidation, and molding strains.

Abstract: Mold cycle time is accelerated by employing thermally insulating surface temperature boosters, which are of a minimum thickness to promote cooling by heat transfer through the boosters. According to the thermal transfer properties of the insulating boosters and the respective temperatures of the molten material and the dies, the temperature of the cavity surface is raised by contact with the molten material to equal or exceed the temperature required to produce a molded article, preferably just until the time that the mold is fully filled. Heat transfer through the boosters to the dies then cools and solidifies the molded article until it can be removed from the mold. The temperature boosters result in increased cavity surface temperatures, such that the mold dies can be kept at substantially lower temperatures. The overall result is a reduction in mold cooling time and therefore acceleration of mold cycling.

Abstract: A process and device for resurfacing damaged compact discs by melting a thin layer of the optical surface of said compact disc so that it reflows and fills any scratches or other imperfections. The result is a smooth and optically transparent surface equivalent to the condition of a new compact disc.

Abstract: The present invention provides a method for manufacturing an optical component that have increased transmittance in the ultraviolet region of the spectrum. The method includes the steps of cutting out a part from a block material; polishing optical sides of the part; subjecting the part to heat treatment at a temperature of between 100 and 900° C.; and subjecting the part to acid treatment.

Abstract: A system and method cure a combination of a top and a bottom substrate with a resin disposed in-between. A cure platform includes a chuck on which the combination rests. A cure device cures the resin. An actuation assembly separates the chuck from the platform to thermally isolate the chuck during a curing operation performed by the cure device. A post cooling assembly may be provided to cool the chuck and the combination after a curing operation is performed by the cure device.

Abstract: A method of making a stamper for use in a data storage disk molding process. The method includes making a first stamper including the steps of providing a stamper body having an information layer thereon. The information layer is covered with a first metal layer. A second stamper is made from the first stamper, which includes the steps of covering the first metal layer with a second metal layer to form a stamper assembly, wherein the first metal layer and the second metal layer are bonded together. The first metal layer and the second metal layer are removed from the stamper assembly to form the second stamper, wherein removal of the first metal layer and the second metal layer is nondestructive to the information layer. In one application, the first metal layer and the second metal layer are made of nickel.

Abstract: In the method of manufacturing an optical recording medium according to the present invention, when an optical recording medium having at least first and second minute concave and convex surfaces formed thereon is manufactured, the first and second minute concave and convex surfaces are simultaneously molded on both surfaces of a substrate of the optical recording medium. Therefore, it is possible to manufacture a multilayer optical recording medium having an excellent symmetrical structure with respect to a vertical cross section direction of the substrate, i.e., in the thickness direction of the optical recording medium. Moreover, it is possible to effectively suppress the deformation thereof resulting from curing or shrinkage of an light curing resin or the like, absorption or removal of vapor in the air into or from a substrate, a transparent intermediate film or the like, and so on.

Abstract: A method and apparatus are provided for improving the durability of lubricating layers on the surfaces of disks. The lubricating layers on the disks are exposed to ultraviolet and infrared radiation of sufficient duration and energy to reduce the total thickness of the layer but retain at least about 40% of the thickness of the remaining layer in bonded form. The useable lifetime of the lubricating surface is prolonged by treatment of the lubricating layer in this manner.

Abstract: A method of making a stamper for use in a data storage disk molding process. The method includes making a first stamper including the steps of providing a stamper body having an information layer thereon. The information layer is covered with a first metal layer. A second stamper is made from the first stamper, which includes the steps of covering the first metal layer with a second metal layer to form a stamper assembly, wherein the first metal layer and the second metal layer are bonded together. The first metal layer and the second metal layer are removed from the stamper assembly to form the second stamper, wherein removal of the first metal layer and the second metal layer is nondestructive to the information layer. In one application, the first metal layer and the second metal layer are made of nickel.

Abstract: An injection molding process wherein the times of heating to melt a resin are reduced to minimize the thermal hysteresis and to decrease the deterioration of physical properties caused by the thermal hysteresis, so that high quality information recording disks may be produced. A molding process wherein the plasticating and the injection and filling of a material resin are carried out in separate cylinders, allows constant molding for a long period of time. A material resin such as polycarbonate is supplied without predrying to an injection apparatus for a first time molding. Resin is kneaded by the apparatus while volatile components are heated to be vaporized and exhausted through a vent port. An inert gas atmosphere is provided within the cylinder to prevent the material resin from being oxidized. Since predrying can be dispensed with, the thermal hysteresis will be extremely small and the deterioration of the resin caused by such heating may be suppressed.

Abstract: A molded resin article is prepared by introducing a thermoplastic resin having a temperature greater than a transfer starting temperature into the cavity of a mold, which is retained at a temperature less than the transfer starting temperature, and injection-molding the thermoplastic resin in the mold in which the heat capacity of a surface on the cavity side is set such that the temperature of the thermoplastic resin near the surface of the mold, which resin is cooled in said mold to a temperature less than the transfer starting temperature, is increased again to a temperature exceeding the transfer starting temperature after the cavity is filled with the thermoplastic resin.