Abstract: A packaging structure of the present invention is provided for an ink tank having an ink supply port and an atmosphere communicating port. It has a seal member for sealing the ink supply port, a seal member for sealing the atmosphere communicating port, and an integrated covering member for integrally covering the ink tank having at least these seal members. A partial breakage of the covering member leads to open the atmosphere communicating port at first. Thus, the combination of the packaging structure and the ink tank is constructed so as to open the atmosphere communicating port at first with reliability. It is functionally required at the time of pulling out the ink tank from the package and also at the time of physical distribution without causing an ink leakage, regardless of the shape of the ink tank.

Abstract: A roller-shaped stamper has a scale portion with a light transmitting forming portion for forming the light transmitting portion on the resin, and a light shield forming portion for forming the light shielding portion of the resin, wherein the forming portions are alternately arranged with a constant pitch in a direction of rotation of said roller-shaped stamper; a plurality of scale portions are arranged in a direction normal to the direction of rotation of the roller-shaped stamper; and a groove disposed between the plural scale portions and extending in the direction of rotation of the roller-shaped stamper for exhausting air otherwise trapped between the resin and the roller-shaped stamper.

Abstract: Optical recording mediums are prepared by extrusion molding. In the extrusion molding, a thermoplastic resin heated to a given temperature is pressed between a roll stamper and a roll opposite thereto. A gap between the roll stamper and the roll is precisely defined by belt members fixed on each side of the roll where the roll does not come into touch with the thermoplastic resin. The joints of the respective belt members are formed at positions different from each other on the periphery of the roll. Alternatively the gap may be defined by cutting the roll substrate at a part on which the stamper member is fixed, or by interposing endless belts with a given thickness between the roll stamper and the roll. The stamper member provided on the roll stamper is reduced in stress, and has a surface precision of 10 .mu.m or less.

Abstract: The present invention provides a process using a roll stamper which molds a substrate sheet for information recording mediums by continuously transferring preformat patterns on a resin sheet. The roll stamper has the feature that the preformat pattern on the roll stamper has a value of b/a of greater than 1 when the length of the preformat pattern in the direction parallel to the direction in which the resin sheet is transported is defined as a and the length in the direction perpendicular thereto as b.

Abstract: An optical recording medium is disclosed which comprises a substrate containing a polycarbonate resin and a recording layer. The substrate contains copolycarbonate resin having constitutional units represented by the formulae (x) and (y) ##STR1## wherein Z of the formula (x) is a direct bond, alkylidene, --O--, --S-- or --SO.sub.2 --; X is H, halogen, alkyl, aryl, aralkyl, alkoxy, aryloxy or aralkyloxy; R.sub.1 is H, alkyl or aralkyl; m is an integer of 1 to 3; Y of the formula (y) is alkylidene, aryl-substituted alkylene, aryl, --O--, --S--, --CO-- or --SO.sub.2 --; and each of R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is H, halogen or alkyl!.

Abstract: A roll stamper for forming an information recording medium substrate has a stamper member having a pattern corresponding to a pre-format for an information recording medium formed in its obverse surface, fixation members fixed to both end portions of a reverse surface of the stamper so as to be integral with the stamper member, and fit grooves formed in a circumferential surface of a specular roll base parallel to the axis of the specular roll base. The fixation members are fitted in the fit grooves, and the stamper member is fixed on the circumferential surface of the specular roll base. The roll stamper also includes a mechanism for applying a tensile force to the stamper member. This roll stamper is used in an apparatus having an extruder for melting and extruding a resin to form a resin sheet and a specular roll facing the roll stamper to continuously form the information recording medium substrate.

Abstract: A process for manufacturing a substrate sheet for information recording mediums using a roll stamper including a flexible stamper member having a pattern corresponding to a preformat for an information recording medium, a first fixing member and a second fixing member integrally joined to both ends of the stamper member, and a pair of fit grooves capable of fittingly receiving the fixing members and formed in the periphery of a specular roll substrate in parallel to the axial direction of the specular roll substrate. The fixing members are fitted to the fit grooves so the stamper member is fixed along the periphery of the specular roll substrate between fit grooves. The first fixing member has a first member with a coefficient of linear expansion substantially equal to the coefficient of linear expansion of the stamper member and a second member having a larger coefficient of linear expansion than the coefficient of linear expansion of the first member.

Abstract: A method for preparing a substrate sheet for an optical recording medium has the steps of controlling a roll stamper having a preformat pattern on the peripheral surface thereof and a molding roll disposed with a predetermined gap between the same and the roll stamper so that they have a predetermined temperature, feeding a thermoplastic resin heated to a predetermined temperature to the gap from a means for extruding the thermoplastic resin disposed on the upstream side of the gap, while the roll stamper and the molding roll are rotated at a predetermined rotational frequency, and then molding the thermoplastic resin into a sheet by pressing the resin between the roll stamper and the molding roll to transfer the preformat pattern to the resin.

Abstract: A roll stamper used in a process of continuously forming a uniform sheet of a resin from which information recording medium bases are obtained. This roll stamper has a stamper member having in its surface a pattern corresponding to a pre-format pattern of an information recording medium, fixing members fixed on opposite end portions of a reverse surface of the stamper member so as to be integral with the stamper member, and a specular roll base having an engagement groove formed in its circumferential surface parallel to its axis. The stamper member is fixed on the specular roll base by fitting the fixing members in the engagement groove. A recess formed in a circumferential surface of the roll stamper as a gap between the fixing members is filled with a filler so that the roll stamper circumferential surface is substantially smooth. Side surfaces of the fixing members and/or the engagement groove are shaped as to suitably retain the filler.

Abstract: A method for molding a substrate sheet for an optical recording medium by transferring a preformat pattern from a molding roll to a resin sheet molded by melting and extruding a resin. The molding roll has a roll base, a stamper detachably fixed on the peripheral surface of the roll base, and a resin layer interposed between the roll base and the stamper.

Abstract: A roll stamper which molds a substrate resin sheet into an information recording media by continuously transferring preformat patterns on the substrate resin sheet, and a production process therefor. The preformat pattern on the roll stamper has a value of b/a of greater than 1 when the length of the preformat pattern in a direction parallel to the direction in which the resin sheet is transported is defined as a and the length in a direction perpendicular thereto as b.

Abstract: An apparatus and method for manufacturing a substrate sheet for information recording mediums having a roll stamper consisting of a flexible stamper having a pattern corresponding to a preformat for an information recording medium, the flexible stamper being fixed along the corresponding periphery of a roll substrate. A roll is placed opposite the roll stamper. A molten-resin sheet wider than the flexible stamper member is formed. The apparatus has means for bringing the edges of a resin sheet into contact with the roll substrate before releasing the resin sheet from the roll stamper. The temperature is controlled, so that a temperature difference on the surfaces of edges of a resin sheet and a preformat pattern transfer area of the resin sheet is kept within 30.degree. C. when the resin sheet is separated from the roll stamper after the molten-resin sheet has been pressed between the roll stamper and roll.

Abstract: A roll stamper for forming a substrate sheet for information recording mediums has a flexible stamper member having a pattern corresponding to a preformat for an information recording medium; a first fixing member and a second fixing member respectively joined to both ends of the stamper member in an integral form; and a pair of fit grooves capable of fittingly receiving the fixing members, formed in the periphery of a specular roll substrate in parallel to the axial direction of the specular roll substrate. The fixing members are so fitted to the fit grooves that the stamper member is fixed along the periphery of the specular roll substrate between the fit grooves.The first fixing member has a first member showing a coefficient of linear expansion substantially equal to the coefficient of linear expansion of the stamper member and a second member having a larger coefficient of linear expansion than the coefficient of linear expansion of the first member.

Abstract: A roll stamper for forming an information recording medium substrate has a stamper member having a pattern corresponding to a pre-format for an information recording medium formed in its obverse surface, fixation members fixed to both end portions of a reverse surface of the stamper so as to be integral with the stamper member, and fit grooves formed in a circumferential surface of a specular roll base parallel to the axis of the specular roll base. The fixation members are fitted in the fit grooves, and the stamper member is fixed on the circumferential surface of the specular roll base. The roll stamper also includes a mechanism for applying a tensile force to the stamper member. This roll stamper is used in an apparatus having an extruder for melting and extruding a resin to form a resin sheet and a specular roll facing the roll stamper to continuously form the information recording medium substrate.

Abstract: A process for producing a resin molding having a concave-convex pattern on the surface includes the steps of providing an original die having a concave-convex pattern on the surface and a substrate having a flat surface, thereby counterposing the concave-convex pattern surface and the flat surface to each other through a spacer and forming a cell with a cavity formed by the original die, the substrate and the spacer; making an internal pressure of the cell cavity lower than an external pressure thereof, thereby filling at least one of a liquid polymerizable component and a liquid resin into the cavity due to a pressure difference between the external pressure and the internal pressure; curing at least one of the polymerizable component and the liquid resin in the cavity, thereby making a replica; and peeling the original die from the replica, thereby obtaining a resin molding.

Abstract: A process for producing a roll stamper which molds a substrate sheet for information recording mediums by continuously transferring preformat patterns on a resin sheet. The roll stamper has the feature that the preformat pattern on the roll stamper has a value b/a of greater than 1, where the length of the preformat pattern in the direction parallel to the direction in which the resin sheet is transported is defined as a and the length in the direction perpendicular thereto as b.

Abstract: A substrate for an optical card having tracking grooves in a stripe form formed on the surface of an extrusion-molded thermoplastic resin sheet is characterized in that the direction of the tracking grooves is in parallel to the extrusion direction of the thermoplastic resin sheet, and the recording or reproduction using the optical card is characterized by that the optical card is bent and reciprocally moved along the direction of tracking grooves.

Abstract: A roll-stamper for forming substrates of an information-recording medium includes at least one stamper being fastened along a peripheral face of a mirror roller, carrying on a surface thereof patterns each corresponding to a preformat for an information recording medium, also having stoppers fixed along both edges on the reverse side thereof, and being fastened to the mirror roller by inserting the stoppers respectively into negative stopping-grooves cut into the mirror roller in parallel with the axis of the mirror roller.

Abstract: Disclosed are a master holder of a stamper electroforming apparatus and an electroforming method using this master holder. The master holder is for use in a stamper electroforming apparatus that forms a metal film by electroforming on a conductive film formed on a master having a minute relief pattern on its surface; and this master includes: a contact ring for electrically connecting the conductive film to a power source; and a structure for controlling the rate at which the metal film is formed, which structure is provided on the contact ring and adapted to control the metal-film-formation rate such that the thickness of a peripheral portion of the metal film gradually decreases in the vicinity of the contact ring.

Abstract: A process for producing a stamper having a roller form is disclosed. The process includes the steps of: forming a layer of a photoresist on a stamper substrate having a roller form; causing a flexible exposure mask having a predetermined pattern to substantially contact the roller stamper substrate and exposing the roller stamper substrate to light by the medium of the exposure mask; subjecting the photoresist layer to development thereby to form on the stamper substrate a pattern of the photoresist corresponding to the pattern of the exposure mask; and forming on the stamper substrate an unevenness pattern corresponding to the pattern of the photoresist.