Sony Corporation

Sony Disc & Digital Solutions Inc.

Sony Disc Technology, Inc.

Shinsuke Kishi

Hideaki Yoshimura

Osamu Matsuura

Kazuhiro Miura

Toshiyuki Kashiwagi

Shin Masuhara

Yuji Akiyama

Nobuyuki Arakawa

Asao Kurosu

A large capacity recording medium is formed by bonding at least two disc-shaped recording plates to provide a structure adapted to absorb any manufacturing errors in the direction of the height of the recording medium.

Optical disc and disc cartridge containing the same

A spaceis formed at a tip portion of a nozzleso as to decrease a thermal transfer of the nozzle. Alternatively, a center portion of one of a semi-spherically protruded surface of the tip portion of the nozzleand a semi-spherically recessed surface of a sprue bush protrudes so that the radius of curvature of one semi-spherical surface is the same as the radius of curvature of the other semi-spherical surface. As a result, since the nozzleand the sprue bushare surface-contacted, heat of the tip portion of the nozzleabsorbed to the sprue bushis increased. Thus, the temperature of the tip portion of the nozzlecan be lowered easily. After the resin material injected into the molding cavityis cooled, when the sprue portion is removed from the fixed die, a tip portion of a rod-shaped protrusion portion of the sprue can be properly cut.

Injection molding apparatus and injection molding method

A resin ringis press-fitted into a grove portion formed in an inner periphery surface of an interlocking ring. The resin ringis made of a hard resin such as Teflon. The resin ringas a low frictional lubricative member is interposed between the interlock ringand an outer periphery ring. In addition, a cavityas a closed space is formed between a stamperas a molding surface of a fixed side mirrorand a mirror side molding surfaceof a moving side mirror. While the moving side mirroris being press-contracted to the fixed side mirror, when a resin material is filled into the cavity, the outer periphery ringis slidably held in a groove of the moving side mirrorwith predetermined clearances. In the interlock ring, a plurality of openingswhich relieve gas produced by the disc resin material filled into the cavityare formed.

Molding die for disc substrate

A clamping apparatus includes a fixed die plate () fixed to a frame (), four tie rods (), () extending in the horizontal direction and respectively fixed to the fixed die plate () in parallel to each other, a moving die plate () supported to the four tie rods (), () so that the moving die plate () can slide freely and a clamping mechanism for moving the moving die plate () forward and backward along the four tie rods (), (). This clamping apparatus comprises a guide mechanism () for downwardly or upwardly supporting the moving die plate () and which allows the moving die plate () to move in the opposite direction of gravitation.

Clamping apparatus

The present invention is directed to an injection molding apparatus and method capable of preventing the occurrence of over-packing. The apparatus includes a pair of dies for forming a plurality of cavities therebetween; die closing devices for closing the pair of dies under a prescribed pressure; an injection device for injecting a molten resin into respective cavities under a prescribed pressure; and, a control device for controlling the die closing devices and the injection device. Further, the apparatus comprises a plurality of pressure sensors for detecting respective pressures in respective cavities and a control device that controls the injection device and/or the die closing devices to reduce the rate of injection of the molten resin and/or the force of closing the dies and, otherwise, stops the injection and/or the die closing operation when the pressure difference between cavities is found to be greater than a prescribed value on the basis of sensed values from the respective pressure sensors.

Injection molding apparatus and method

An optical disc capable of preventing damages on a printing plate and an injection compression molding die capable of producing such optical disc substrate without raising the accuracy of the die are provided. An optical disc substrate according to one embodiment of the present invention has a ring-formed projected portion on the outer periphery of the printable plane slightly recessed inwardly from the outer edge of the disc. Such optical disc substrate can be produced using a molding die in which a readout-side mirror has a ring-formed groove on the inner surface thereof in the vicinity of a sliding portion between such readout-side mirror and a cavity ring.

Optical disc and injection compression molding die for producing the same

An optical disc molding device has a pair of molds for injection molding a disc substrate within cavities, and a stamper supported within at least one cavity, for molding a data recording surface in such a manner that the inside diameter side of the stamper supporting surface of the cavity protrudes inwardly in the disc thickness direction from the data recording surface. The flatness of a laminated reference plane has thus been deteriorated by burrs occurring on a disc substrate.

Optical disc molding device and molding method for optical disc

A multi-cavity injection molding apparatus capable of simultaneously molding a plurality of optical disk substrates with a simple construction. The injection molding apparatus is constituted of a mold unit having a plurality of cavities and an injection unit for supplying a molten resin to the mold unit. The injection unit is provided with a plurality of nozzles for injecting the molten resin into the cavities, respectively.

Growing community of inventors

Saitama, Japan

Shinsuke Kishi