Abstract: In an injection molding machine 1 for supplying clean air 10 to a die 8 in a direction perpendicular to a direction that opens/closes the die 8, in order to effectively pass the clean air 10 through an opened space in the die 8 so as to prevent dust from depositing on a die cavity surface or a molded product when the die 8 is opened and a ventilating hole 12 is provided in a safety door 11 provided so as to be in parallel with the die opening/closing direction.

Abstract: The transfer plate is energized and heated uniformly in the state in which the transfer plate heated through the electric resistance heating is separated slightly from the specular surface of the specular plate, then, immediately before the die is closed, the transfer plate is pressed against the specular surface to adhere thereto and, at the same time, the resin material is supplied to the cavity quickly and, after that, at the same time as the molded product is shaped completely, the transfer plate is de-energized so that the resin material in the cavity is quenched at the controlled temperature of the specular plate that is set to be lower than the heating temperature of the transfer plate.

Abstract: In an injection molding machine 1 for supplying clean air 10 to a die 8 in a direction perpendicular to a direction that opens/closes the die 8, in order to effectively pass the clean air 10 through an opened space in the die 8 so as to prevent dust from depositing on a die cavity surface or a molded product when the die 8 is opened and a ventilating hole 12 is provided in a safety door 11 provided so as to be in parallel with the die opening/closing direction.

Abstract: The transfer plate is energized and heated uniformly in the state in which the transfer plate heated through the electric resistance heating is separated slightly from the specular surface of the specular plate, then, immediately before the die is closed, the transfer plate is pressed against the specular surface to adhere thereto and, at the same time, the resin material is supplied to the cavity quickly and, after that, at the same time as the molded product is shaped completely, the transfer plate is de-energized so that the resin material in the cavity is quenched at the controlled temperature of the specular plate that is set to be lower than the heating temperature of the transfer plate.

Abstract: The stamper 16 is disposed opposing to the cavity 3 formed between the fixed mold 1 and the movable mold 2, as a holding means of the circumference of the stamper the flat type of holding means 17 is provided, and when using this molded product for molding a disk, the air for releasing the mold is blown out from a plurality of air passages into the cavity. The air from the outer circumference side of the disk is blown out from one of the air supply opening provided on at least one of the recessed portion 28 formed on the holding means 17 and the mirror plate 15 opposing to the recessed portion 28 simultaneously, before or after the operation time of opening the mold during the time of restoring stroke of the holding means from being pushed against the resilient means 32 through the gap 30 between the inside projection wall 27 of the holding means 17 and the stamper surface 16a.

Abstract: A mold for injection molding thin discs for DVD has a cavity (C) bounded by a information-bearing stamper (29) surface, a mirror plate (31) opposite to the stamper surface, and the tip (33s) of an inserting block (33) at a central opening in the mirror plate. The tip surface (33s) protrudes into the cavity past the surface of the mirror plate between 10 .mu.m and 70 .mu.m. The mirror plate molding surface is slightly frusto-conical, with a gradient Y/R gradually increasing the depth of the cavity toward the periphery. R is approximately 40 mm and Y lies in the range of 5 .mu.m and 30 .mu.m. The mirror plate is preferably manufactured flat on the surface facing the mold, but bolted down onto a frusto-conical backing plate or on top of a central ring, so that it is stressed into the desired shallow cone shape. The invention includes a method of injecting resin with lower clamping force of about 2 tons and then applying a higher force of about 17 tons.

Abstract: Into the cavity formed by closing a stationary mold with a movable mold, material is filled through a gate portion of a female cutter. After the material is filled into the cavity, a male cutter is advanced at a high speed from a starting position S to a vicinity position P of the female cutter, at the position P the advance speed is changed to a low speed and the male cutter advances at the low speed to an advancing limit position E to carry out the gate cutting. Then, the filled material solidifies while being cooled.

Abstract: Method and apparatus for producing a bonded composite disk including a first and a second disk component which are bonded together, using a mold including a first mold half having first concentric elements whose axial end faces cooperate with an annular information-bearing stamper or an annular blank stamper, to provide a first molding surface, and a second mold half having a second concentric elements whose axial end faces provide a second molding surface cooperating with the first molding surface to define a cavity for forming each of the first and second disk components.

Abstract: A mold for molding a disk substrate includes a stationary mold half having a first molding surface and a movable mold half having a second molding surface, which cooperate with each other to define therebetween a mold cavity. Each of at least one of the stationary and movable mold halves has at least one air supply passage for supplying compressed air, and a plurality of air blow passages having respective air inlets in communication with the at least one air supply passage and respective air outlets open to the mold cavity at respective circumferential positions of the mold cavity about a centerline of the mold, for introducing the compressed air from the air supply passage into the mold cavity, to facilitate removal of the molded substrate from the corresponding mold half or halves. The air supply passage and the air blow passages cooperate to provide a plurality of air passages ending at the air outlets which have a substantially same resistance to a flow of the compressed air therethrough.

Abstract: A mold for molding discs includes a outer stamper retainer with an outer peripheral retaining foot to closely contact on the surface of a stamper not to permit compressed air to lead outwards and an inner peripheral retaining foot to contact permit compressed air for releasing molded discs from the stamper to be blown through a groove located between the both feet resulting in increasing the performance of compressed air for releasing molded discs from the stamper.

Abstract: Two disc bases D having different information are molded in a time by a pair of cavities formed when clamping the molds 1 and 2, which are filled with the molten resin by being injected. After taking out the disc bases from the mold by a product taking out apparatus, those are coated with a reflection layer by a sputtering apparatus and subsequently coated with a protection layer by a coating apparatus and finally bonded by a bonding apparatus to obtain a single disc VD. This disc VD can avoid the mechanical troubles such as distortion, bending, twisting or peeling off of the bonded portion in a time lapse after being bonded, because those disc bases VD are molded in a pair of cavities 3, 3 formed in a mold using the material of the same lot, i.e. under the same condition. Representative drawing FIG. 1.

Abstract: A mold for molding a substrate of a disk, including a stationary and a movable mold half which are movable relatively to each other, a positioning ring portion on the movable mold half, for positioning an annular stamper at its center hole, and an ejector sleeve located radially inwardly of the positioning ring portion and movable to remove the substrate from the movable mold half. The ejector sleeve includes a recessing end portion which extends in an axial direction thereof beyond an end face of the positioning ring portion into the mold cavity when the stationary and movable mold halves are placed in the closed position. The recessing end portion has an outer circumferential surface which is perpendicular to the end face of the positioning ring portion, so that an annular recess partly defined by a circumferential shoulder surface is formed by the recessing end portion of the ejector sleeve. The circumferential shoulder surface is formed by the outer circumferential surface of the recessing end portion.

Abstract: A mold for molding an optical disk including a pair of mold halves which cooperate to form a mold cavity for forming the optical disk, an annular plate-like stamper and a stamper holding member. One of the pair of mold halves has an annular recess in a radially inner portion thereof. The stamper has a center hole and is positioned in the mold cavity. The stamper holding member is removably accommodated in the annular recess for supporting the stamper at an inner peripheral portion. The stamper holding member includes a first ring member having an annular collar portion extending radially outwardly from an axial end of the first ring member, and a second ring member removably fitted on an axial end portion of the first ring member. The stamper is positioned such that the inner peripheral portion is interposed between the annular collar portion of the first ring member and an inner portion of the second ring member.

Abstract: A mold is for molding DVD discs to be joined together, back-to-back, to make a single disc. The mold includes a movable moldhalf and a stationary moldhalf. On one of the half-molds an inserting block extends a small distance into the mold cavity, so that the central part of the cavity is thinner than the outer part. The inner part and the outer part correspond approximately to the outer information band and the inner portion of the disc which is grasped. The mold is preferably used in a method using first a lower compression force during resin injection and then an increased force.

Abstract: Method and apparatus for forming a first and a second component disk which are bonded together to produce a bonded composite disk, wherein a first mold for forming the first component disk includes first mutually concentric components cooperating to define a molding surface for forming a bonding surface of the first component disk, while a second mold for the second component disk includes second mutually concentric components cooperating to define a molding surface for forming the bonding surface of the second component disk, and wherein the first mutually concentric components are dimensioned such that at least one of first annular boundaries between adjacent ones of the first mutually concentric components, which boundaries are located on the molding surface, has a diameter different from that of the corresponding second annular boundary between adjacent ones of the second mutually concentric components.

Abstract: In a mold for molding data discs having a stationary cylindrical member and a movable cylindrical member fixed to a stationary moldhalf and movable moldhalf respectively, in each of which a stationary mirror plate and a movable mirror plate are fixed, an outer peripheral ring is set on the outer peripheral surface of the movable mirror plate, having a protrusion in the lower portion of a small inner peripheral surface of the outer peripheral ring for preventing leakage of air blowing into a cavity to release the discs from the stamper.

Abstract: A mold for molding digital data discs has interchangeable stampers. An outer peripheral stamper retainer and a mirror block with a convex portion allow interchange without dismounting the mold. The outer stamper peripheral retainer has a plurality of arcuate slots connected or disconnected to a plurality of rods provided with a stationary half-mold and to a corresponding plurality of holder bushings and a mirror block with a convex portion whose diameter fits an inner diameter of the outer stamper peripheral retainer. The outer stamper peripheral retainer and the mirror block correspond in size with a disc to be molded.

Abstract: A mold for molding disk substrata is capable of changing a set position of a stamper plate on a mold cavity. A pair of mirror plates are respectively for forming the surface of a disc cavity or for back stay of stamper plate. The set position of mounting the stamper plate is capable of being performed due to changing selectively the set position of the mirror plate. An inner stamper holder and stamper plate are held on the mirror plate by vacuum force to admit setting operations to ease.

Abstract: A central aperture of a molded disc being severed by protruding of the gate cutter and also a molded disc being released from a cavity by blowing of air from the passage provided between an inner periphery of the central stamper holder and an outer periphery of the bushing into the cavity, the molten resin with which the protruded gate cutter is surrounded, is pressed by the first protrusion of an ejector sleeve for preventing occurrence of a round corner D formed along the edge of the central aperture and for preventing generating of the clouds on the surface of the information area of the disc.

Abstract: A disc base formed concentrically in the recited order from its center opening to its outer circumferential edge with clamp areas on its two faces, a groove by a stamper holder and a signal area both leading from one of the clamp areas on its one face, and a stack rib on its other face. The diameter of the concentric circuit of the top of the stack rib is slightly larger than the diameter of the concentric circuit of the groove formed by the stamper holder, and the angle of the outer slope of the stack rib is larger than the angle of the inner slope of the same. Also disclosed is a mold for molding the disc base.