Abstract: A press molding apparatus and its method of operation for making an information carrier disc which comprises the steps of maintaining a mass of granular transparent synthetic material in a vacuum, radiating heat from an infrared heating unit to plasticize the synthetic material, and press-molding the plasticized synthetic material.

Abstract: Process for forming a polymeric layer on a substrate comprises placing a substrate to be coated in a mold having a removable lid, injecting a liquid monomer into the mold and into contact with the surface of the substrate to be coated, holding the substrate in place in said mold prior to curing said monomer, radiation curing the liquid monomer, releasing the hold on said substrate prior to significant shrinkage of the curing liquid monomer, and venting said mold to atmospheric pressure at the portion of the mold remote from the surface of the substrate being coated and prior to significant shrinkage of said liquid monomer whereby the substrate moves toward the removable lid. Thereafter, the substrate, which now has a polymeric layer affixed thereto, is removed from the mold.

Abstract: A transparent record disc is provided which may appropriately have video signals optically recorded thereon, the record is composed of a lamination, for example, of pliant transparent plastic on a base of hard transparent plastic. The base provides strength for the record and the pliant plastic permits the video recording to be impressed into the record by simple embossing means, rather than by stamping or molding by which the surface of the record is actually raised above its melting point and caused to flow. An improved process for forming the video recordings on the disc record is also provided.

Abstract: A transfer apparatus is provided for advancing a molded article from the molding station to the flash trimming station of an automated molding press. The transfer apparatus is comprised of a support member having a retainer and an expandable clamp member. The expandable clamp member is mounted within the retainer. The expandable clamp member, in its fully expanded position, has an interior size sufficient to hold a molded article by flash formed about the outer edge of the molded article. In the contracted position, the clamp has an inner edge larger than the size of the flash formed about the outer edge of the article. The transfer apparatus is pivotally mounted to oscillate between the molding station and the flash trimming station. In use, the transfer apparatus is positioned with the clamp member in the fully expanded position between the molds of the molding station so as to form a molding surface against which the flash can be molded in a uniform configuration.

Abstract: At least one layer of a conductive organic polymer, formed by electropolymerization on the anode in a two electrode cell, is bonded to a plastic substrate by compression with sufficient heat and pressure to cause it to bond to the substrate and release from the anode. Improved sandwich-type capacitive electronic discs having an information pattern in ultra thin outer conductive layers which are homogeneous and which contain no conductive particles are formed by this process by providing as the anode a mastering disc containing an information pattern which is the negative of the desired information pattern.

Abstract: A radiation-sensitive carrier body directly utilized as a stamper has a glass substrate, a first highly adhesive layer securely adhered to the substrate, a radiation-sensitive layer which discharges a gas component upon being irradiated with a laser beam and which locally forms a protuberance due to the absorbed energy, a second highly adhesive layer securely adhered to the specific material of the radiation-sensitive layer and which deforms in accordance with deformation of the layer, and a metal layer which has a high releasability to allow easy separation from a optical disk substrate material such as an acrylic material when the carrier body is used as a stamper substrate for manufacturing optical disks. A protuberance formed on the carrier body such as a continuous spiral protuberance allows formation of a corresponding spiral groove in the acrylic material, serving as a pre-track into which desired information will be digitally written by a user.

Abstract: Thin, flexible capacitive electronic discs are formed by directly compression molding a powder composition having a particle size such that no particles are larger than about 400 micrometers and a substantial portion is between about 25 and 300 micrometers and comprising a thermoplastic resin, conductive carbon black particles and suitable additives. An information track is embossed into at least one surface of the disc, preferably simultaneously with the molding step. The discs are from about 0.15 to 0.6 mm thick. Preferably, the discs are about 0.2 mm thick, which is about one-tenth of the thickness of present commercial discs.

Abstract: Capacitive electronic discs having thin conductive layers are prepared by coating a core disc with a finely particulate conductive composition comprising a thermoplastic resin, conductive carbon black particles and suitable additives. The powder coating is compressed under heat and pressure to fuse the powder to the surface of the core disc. An information pattern is embossed therein, preferably simultaneously.

Abstract: Information storage mediums such as video discs and digital audio discs are fabricated by extruding a mass of electrically conductive synthetic resin into a block assembly composed of a pair of separable blocks in which the mass is molded into a cake that is then carried by one of the blocks as separated into a press in which the cake is pressed into an information storage medium or disc blank. The blank is transferred into a trimmer for trimming an overflow off the disc blank as an annular scrap, which is in turn chopped by a chopper into pieces for reuse. A disc from which the scrap has been removed is fed to a hot stamping machine in which an identification foil piece is attached with heat to the disc. The disc with the foil piece stamped thereon is punched to form a central hole by a punching machine.

Abstract: A preform for use in making a video recorded disc in a body of plastic material having substantially flat top and bottom surfaces and a peripheral surface extending between the top and bottom surfaces. The peripheral surface includes a first portion intermediate the top and bottom surfaces and of a peripheral size greater than that of the top and bottom surfaces. Second and third portions extend from the first portion to the top and bottom surface, respectively. Each of the second and third portions has a peripheral dimension which decreases from that of the first portion to that of the top or bottom surface so that the surface of each of the second and third portions is angled away from the top and bottom surfaces, respectively. When the preform is engaged by the molds for making a disc the angled surfaces of the second and third portions serve to minimize if not eliminate the trapping of air and gasses along the surface of the record being formed which cause defects in the record surface.

Abstract: An upper press block for a disc record press comprises a support member surrounding a mould member to which a stamper plate is fixed. Means for adjusting the axis of the stamper plate relative to the support member are provided by four lever arms evenly spaced around the mould member, each lever arm being pivotally mounted to the support member and engaging the periphery of the mould member. Each lever arm is disposed between two opposing cams which may be rotated to adjust the mould block position in a lockable manner.

Abstract: A method and apparatus is provided for trimming flash from the outer edge of thermoplastic molded records and then finishing the outer edge. A molded record having flash on its outer edge is supported on a turntable and then rotated about its center. The flash and the outer edge of the record immediately adjacent the flash are selectively heated, preferably by using a focused infrared lamp, to a temperature above the glass transition temperature. A cutter is then advanced tangentially through the flash to remove the heat-softened flash from the record. The trimmed outer edge is then finished by bringing a shaped surface into contact with the softened edge and holding it there while rotating the record until the outer edge has the desired finished configuration. The heating is discontinued and the trimmed and finished outer edge is allowed to solidify.

Abstract: A transparent record disc is provided which may appropriately have video signals optically recorded thereon, the record is composed of a lamination, for example, of pliant transparent plastic on a base of hard transparent plastic. The base provides strength for the record and the pliant plastic permits the video recording to be impressed into the record by simple embossing means, rather than by stamping or molding by which the surface of the record is actually raised above its melting point and caused to flow. An improved process for forming the video recordings on the disc record is also provided.

Abstract: Stamper plates and backing plates in a tool for the pressing of video discs are recessed to permit the formation of an annular ridge which encircles the information region of a disc and is provided for use in the mechanical removal of a disc from its container. Apertures in an annular recess in a stamper plate are aligned with apertures in the associated backing plate to lead to a manifold which communicates with atmosphere. Air which may be present in the ridge of plastics material during the pressing operation thereby escapes to atmosphere, and blemishes in the ridge due to air entrapment are substantially avoided.

Abstract: Chlorophenyl trialkoxysilane, when added to a fractionated methyl alkyl siloxane lubricant for capacitive electronic discs, improves the playback performance and surface quality of the discs.

Abstract: A specific laser-sensitive layer is formed on a substrate so as to manufacture an original disk. The laser-sensitive layer absorbs energy from a laser beam and locally expands and deforms. The laser beam which has a predetermined beam energy to indicate pretrack information for, for example, a self-write/read type optical disk, is used to irradiate the laser-sensitive layer. A spiral projected pattern is locally formed on the laser-sensitive layer, such that a gas is discharged from laser-incident portion which then expands and deforms. A structure so obtained is used as an original disk.

Abstract: The invention relates to an optically readable information disk, a method of manufacturing same, as well as a device for carrying out the method, in which the information disk which comprises an optically readable information track of information areas situated at a higher and a lower level, is manufactured entirely from a radiation-cured layer of a lacquer containing oligomeric acrylates or methacrylates which on an average per molecule comprise between one and four acrylate groups or methacrylate groups, has a viscosity of 1,000-15,000 cP and comprises a photoinitiator in a concentration of 0.1 to 0.5% by weight. Suitable lacquers comprise notably 1,1'-isopropylene-bis(p-phenoxyethylmethacrylate) or 1,1'-isopropylene-bis(p-phenoxyethylacrylate).

Abstract: A device for producing information recording disks comprises a stamper mount for placing a stamper thereon, a stamper-fixing shaft for fixing the stamper, and a pressing plate for pressing a backing plate toward the stamper after a liquid resin is injected in the space between the backing plate and the stamper. Injection is effected via a passage made at the center of the stamper mount, and the injected resin is stretched outwardly radially by pressing the backing plate. An ultraviolet ray is irradiated to the stretched resin through the backing plate to harden the resin. An injection valve movably received in the stamper-fixing shaft may be used so that uninjected resin is prevented from being hardened. The injection valve may have a center projection as well as a flange portion at its top so that machining for making a center hole of the disk is unnecessary. The periphery of the flange portion may be wetted by the resin before the backing plate is placed on the flange portion.

Abstract: A method of manufacturing capacitance video discs comprising thermoplastic resins and conductive carbon black, wherein said conductive carbon black having an average primary particle size of 25 millimicrons or less is washed by water or an inorganic acid, heated at temperatures of 400.degree. to 1,200.degree. C. in a non-oxidizing atmosphere and wherein the coarse particles having a grain size of 0.05 mm or more are substantially eliminated. This method can provide video discs having reduced surface defects and stability after a moisture-proof test.

Abstract: Video discs are cleaned with a water-based solution to remove water soluble salts from the surface of the discs, thereby reducing the moisture sensitivity of the discs.

Abstract: Release properties of stampers used in the manufacture of capacitive electronic discs are improved by passivating the molding surface of the stamper with an oxidizing agent.

Abstract: A preform for use in making a video recorded disc in a body of plastic material having substantially flat top and bottom surfaces and a peripheral surface extending between the top and bottom surfaces. The peripheral surface includes a first portion intermediate the top and bottom surfaces and of a peripheral size greater than that of the top and bottom surfaces. Second and third portions extend from the first portion to the top and bottom surface, respectively. Each of the second and third portions has a peripheral dimension which decreases from that of the first portion to that of the top or bottom surface so that the surface of each of the second and third portions is angled away from the top and bottom surfaces, respectively. When the preform is engaged by the molds for making a disc the angled surfaces of the second and third portions serve to minimize if not eliminate the trapping of air and gasses along the surface of the record being formed which cause defects in the record surface.

Abstract: The invention relates to a process for obtaining information-carrying disks by moulding from a recorded matrix. The invention makes it possible to obtain a disk having a recording area and intact areas, which are separated by stop areas. The invention more particularly applies to the production of video disks and disks useable in information technology. It facilitates the installation of covers on the disks.

Abstract: Provided is an information recording medium manufacturing device of the type in which a radiation curable layer-forming liquid resin is injected into a gap between a planar stamper carrying an information recording signal pattern to be transcribed and a planar flexible carrier member having at least one signal pattern carrying surface through means, for injecting the liquid resin, then the liquid resin is uniformly developed all over the surface of the carrier member by pressing a holding plate against the carrier member, and is set by irradiating radiant rays so as to form a transfer layer, thereby to obtain an information recording medium by separating from the stamper the carrier member united with the transfer layer.

Abstract: A video disc is molded in an apparatus which includes a pair of opposed mold members each having a mold cavity in its surface which faces the other mold member and a stamper is mounted across the mold cavity in each of the mold members. Each stamper has on its surface a surface relief pattern arranged along a spiral path. The stampers are arranged on the mold members so that any imperfections in the mold members which may pass through the stampers and be impressed on the disc being molded are aligned with areas of the stamper which do not contain information which impacts the picture quality so that such imperfections are impressed in areas of the disc which will not adversely impact the perceived picture quality during playback of the disc.

Abstract: A method of fabricating an information signal recorded medium of the electrostatic capacity type is disclosed. The medium is made of a vinyl chloride resin composition comprising a conductive material such as carbon black. The resin composition is applied with water or steam when kneaded at high temperatures, by which deposition of undesirable inorganic impurities such as alkali metal or alkaline earth metal salts on the medium surface can be avoided as will otherwise be experienced. The water or steam is substantially removed by completion of the kneading.

Abstract: A method for manufacturing an information memory disk comprises a process for preparing a die having an annular first rugged portion corresponding to tracks, and an annular second rugged portion corresponding to a positioning mark and concentrically located against the tracks, a process for manufacturing by the use of the die a blank having an annular rugged tracks corresponding to the first rugged portion and an annular rugged positioning mark corresponding to the second rugged portion, a process for detecting the position of the center of the blank on the basis of the positioning mark, a process for boring a hole centering around the center of the positioning mark through the blank, and a process for forming a light reflecting layer on the annular rugged track.

Abstract: A method for manufacturing high information density storage disks, suitable for optical reading, out of transparent synthetics having a high glass temperature and high dimensional stability. The present injection molding method avoids potential double diffraction disruptive effects created by frictional or shearing forces. The synthetic material which is to be pressed is injected into one of the mold halves at a temperature that significantly exceeds the pressing temperature of the compression form and is injected so as to form a lump of the material. The pressing step wherein the compression form is closed down to a squeezing gap width is initiated prior to the termination of the injection operation. Likewise the cooling operation is initiated prior to the termination of the pressing step and both the cooling and pressing operations chronologically proceed at approximately an exponential rate.

Abstract: A substrate of a recording member comprising a hard base, a first organic substance layer which is formed on the base, and a second organic substance layer which is made of a solvent-soluble organic substance and which is formed on a surface of the first organic substance layer opposite to a surface thereof lying in contact with the base. This substrate can be reused.

Abstract: High density information discs, such as video discs, which have been treated with an ammonium salt become resistant to and stable under conditions of high relative humidity, even after repeated exposure to such conditions for extended periods of time. The treatment with the ammonium salt is accomplished by use of a bath of an aqueous solution of the ammonium salt, with the preferred ammonium salt being ammonium chloride.

Abstract: An apparatus for molding information discs includes a pair of mold plates, at least one of which is movable toward and away from the other, and adapted to form a mold cavity therebetween, a center hole forming pin slidably mounted in one of the mold plates and a center plate in the other mold plate in alignment with the center hole forming pin. The center hole forming pin has a recess in its end which faces the center plate and a plurality of passages extending substantially radially therethrough from the recess to the outer surface thereof. The passages allow the flow of mold material therethrough as the center hole forming pin is moved through the mold material in the forming of the center hole to reduce the force necessary to move the pin through the mold material.

Abstract: A center plate for an apparatus for molding recorded discs is disclosed which includes a cylindrical body having an internal recess and a plug secured across the bottom end of the recess. The plug has a pair of passages therethrough opening into the internal recess. An adapter is secured to the plug. The adapter has a pair of ports and a separate universal connection between each of the ports and a separate one of the passages in the plug. This provides for a flow of a heat control medium through the center plate and permits ease of connecting pipes to the ports to provide the flow of the heat control medium.

Abstract: A video disc member is described having a uniform value of birefringence over the entire information storage surface of the disc. This value of birefringence is the same at the inner information storage radius as at the outer information storage radius. The preferable composition of the video disc is a specially prepared polymethylmethacrylate, referred to as PMMA. The method of molding the improved video disc member includes an extended drying time for said composition and increasing the melting temperature. The increase in melt temperature provides a low and uniform value of birefringence. The improved drying cycle eliminates splay marks, blisters and other surface imperfections as compared to manufacturer recommended drying times.

Abstract: A method and device for manufacturing a record carrier is disclosed in which a liquid moulding resin is deposited in a cavity formed in the surface of a mould which also has at least one data track. Thereafter a flexible substrate, having a central projection, is deformed into a convex shape and is pressed against the moulding resin. As the projection on the substrate enters the mating cavity in the mold, the resin is squeezed out of the cavity and rolled out across the mould surface by the substrate which is flattened into a planar form during the pressing step. The moulding resin is then cured and the assembly of the substrate with attached, cured resin layer is removed from the mould.

Abstract: A laminated recorded disc of the type having a core material surrounded by a surface layer of a conductive material is made from a preform having a core surrounded by the conductive material. The preform is made in a mold in which the conductive material is first injected into the mold and then the core material is injected into the conductive material. The disc is made from the preform by placing the preform between the platens of a compression mold and closing the heated platens against the preform. The heated platens heat and apply pressure to the preform to cause the materials of the preform to flow radially outwardly until the materials fill the mold cavity formed by the completely closed platens.

Abstract: Method for the manufacture of flexible disks from engraved moulds by means of a compression press comprising starting with a roll of plastic material and bringing a strip of material between the open plates of a compression press without making a preliminary hole in said strip. A preliminary hole is made during the closing of the plates by means of a first punch matched to a complementary punch, said punches serving as centering means for the two moulds, then by the guidance of the first punch in the complimentary punch for the centering of the moulds with respect to one another. The central hole is cut when the plates are closed by means of the complementary punch which is maintained in the raised position throughout the end of the pressing cycle.

Abstract: Video discs are dried by first spraying the surface with liquid fluorocarbon to remove water and heating the disc so as to prevent water condensation during evaporation of the fluorocarbon, preferably in a fluorocarbon vapor.

Abstract: A molding apparatus for molding a recorded disc includes a pair of mold plates adapted to form a mold cavity therein and a center hole forming pin slidably mounted in one of the mold plates. The center hole forming pin is larger in diameter than the hole to be formed and has a projection on its end which is of a diameter equal to the hole to be formed and a length about one-half the length of the hole to be formed. The other mold plate includes a projection extending therefrom of a diameter equal to the diameter of the hole to be formed and a length one-half the length of the hole. In the molding of the disc the projection on the center hole forming pin engages the projection on the other mold plate to form a hole in which a flash is spaced from the edges of the hole.

Abstract: High density information discs, such as video discs, which have been treated with a fluorinating agent become resistant to and stable under conditions of high temperature and high relative humidity, even after exposure to such conditions for extended periods of time. The treatment with the fluorinating agent is accomplished by use of a bath of an aqueous solution of a "soft" fluorinating reagent, such as fluorosilicic acid or fluoroboric acid.

Abstract: A method for manufacturing modulated disc records (i.e. video or audio records) including bonding a plastics material foil to the unmodulated face of a stamper plate before the stamper plate is secured between the rams of the record press. This method obviates the necessity for backsanding the stamper plate, as hitherto adopted procedure which was time consuming, unreliable and often hazardous.

Abstract: A process whereby the reflective coating of a video disc is applied to the disc directly in the press in which the disc is stamped by the use of fluid organometallic compounds.

Abstract: An apparatus for molding recorded discs includes a pair of opposed mold plates at least one of which is adapted to move toward and away from the other. The mold plates have opposed surfaces which are adapted to form a mold cavity therebetween. A center plate is mounted in each of the mold plates with each center plate having a surface adjacent the opposed surface of the mold plate. One of the center plates has a passage therethrough with a center hole forming pin slidably mounted in the passage. The one center plate has an annular groove in the surface of the passage adjacent the end surface of the center plate. The groove is adapted to receive some of the molding material to form a seal between the center plate and the center hole forming pin and thereby minimize the extent of the formation of flash on the surface of the molded disc.

Abstract: A mold for molding an information record having a relatively large diameter hole therethrough includes upper and lower mold members movable toward and away from each other. The upper mold member has a hole-forming pin extending therethrough and slidable therein. The pin has a recess in its end surface which faces the lower mold member. The recess has in a surface thereof at least one re-entrant which forms a lip. In molding a record, a plastic preform is placed between the mold members. The heated mold members are closed against the preform causing the plastic material to flow outwardly and fill the cavity between the mold members. The hole-forming pin is pushed through the plastic material with some of the plastic material filling the recess to form the hole in the record. When the mold members are separated the plastic material in the recess in the pin is retained in the recess by the lip.

Abstract: High density information discs that have been compression molded from a conductive carbon-containing polyvinylchloride molding composition are cleaned with a water based solution to remove water soluble salts from the surface of the disc, followed by a high temperature aqueous wash wherein the temperature is from about 110.degree. to about 130.degree. F. These discs have improved environmental stability.

Abstract: An improved apparatus and method of molding a high density information disc which includes maintaining the molding composition at an elevated temperature between the extrusion step and the record pressing step, such that the resultant disc is of improved quality. A heated shot cup is provided to maintain the extruded molding composition at the elevated temperature and in which the same is molded into a preform from which the disc is pressed.

Abstract: It has been found that a layered recording disc having an inexpensive core layer and high quality recording groove-accepting outer layers can be made in a relatively simple manner through an application of the technique known as coextrusion, wherein a common die, e.g. a coextrusion die (10) having a die orifice (11) for a plurality of streams (13, 23, and 33) provides a multilayer coextrudate (60) having a plurality of layers (64, 74, and 84). The coextrudate (60) can be cut into segments (60a) with a suitable cutting means (20). The coextrudate segments can be substantially of record thickness with a circular periphery. Alternatively, coextrudate segments (60b) can be much thicker than a record and much smaller in surface area. In either case, segments can be compression molded into discs (100) having the desired profile and/or grooves.

Abstract: Method for the manufacture of flexible disks from engraved moulds by means of a compression press comprising starting with a roll of plastic material and bringing a strip of material between the open plates of a compression press without making a preliminary hole in said strip. A preliminary hole is made during the closing of the plates by means of a first punch matched to a complementary punch, said punches serving as centering means for the two moulds, then by the guidance of the first punch in the complimentary punch for the centering of the moulds with respect to one another. The central hole is cut when the plates are closed by means of the complementary punch which is maintained in the raised position throughout the end of the pressing cycle.

Abstract: The invention relates to a method of manufacturing a plastic record carrier, in particular a video disc, in which a mold is provided with a fluid molding resin. A substrate is then deformed into a convex shape and pressed against the resin disposed on the center of the mold. The molding resin is rolled over the surface of the mold with a circular fluid front while the shape of the substrate is simultaneously changed from convex to planar form. After the molding resin has been spread over the entire mold and the planar substrate bears against the resin layer, the molding resin is then cured. The substrate is preferably deformed by flexibly supporting a planar substrate about its edge and then applying a different gas pressure on both sides of the substrate. The molding resin is preferably radiation-curable and is cured by exposure to, for example, ultra-violet light through the substrate.

Abstract: An improved method for replicating a spiral groove pattern. The pattern is recorded in a photoresist layer which is then developed to reproduce the pattern in the photoresist layer. The pattern is transferred to a metal layer and formed in the surface of a plastic substrate. The improvement comprises the additional steps of asymmetrically irradiating the photoresist layer and removing the irradiated photoresist surface layer to produce a photoresist layer of uniform thickness.

Abstract: An information carrying element comprising a substrate having adhered to at least one surface thereof a separate layer having a thickness of 1.0 to 100 microns and a circular or spiral pattern of surface variations provides a particularly useful element when said separate layer comprises an abrasion resistant polymer layer derived from 30 to 100% by weight of an epoxy-terminated silane.