Abstract: The present invention provides a sputtering apparatus employed for producing an optical disc, for example, wherein a material to be processed by sputtering, such as a disc base plate, is placed in a vacuum chamber having an opening for entrance and exit of the material and a sputtering station, and is transported between the opening and the sputtering station by a rotary arm or arms, in such a manner as to simplify and reduce the size of the vacuum chamber and increase the production quantity per unit time.

Abstract: The sputtering apparatus for the present invention is used for manufacturing optical discs. On loading and unloading of disc substrates to and from a vacuum chamber, a disc entrance and exit opening provided on the vacuum chamber is closed by a tray having an opening at the center thereof on which the disc substrate is placed and a push up rod having a closing side closing the opening of the tray on the lower side thereof. Sealing of the disc entrance and exit opening may be made positive and the vacuum chamber is uniformly evacuated so that an excellent sputtering can be performed.

Abstract: The present invention relates to a submarine optical fiber cable which is comprised of a plurality of relatively large diameter tension wires wound around an optical fiber unit in a close fitting manner so as to form a single layer which acts as a tension body, and root portions between the first tension wires caused by winding the first tension wires which covered by relatively small diameter second tension wires. Due to the second tension wires, deformation of the tension body of the stranded wires can be prevented and the pressure resistance and the tensile strength can be improved.

Abstract: Cross-sectionally fan-shaped metal segments 10a, 10b and 10c, shown in FIG. 1, are longitudinally assembled along an optical fibre to form a pressure-resistant sheath 10 for protecting an optical fibre unit for use in a transmission medium of a submarine optical fibre cable. The inner surfaces 11a, 11b, and 11c, shown in FIG. 1, of the metal segments 10a, 10b and 10c as well as all the contact faces 12a, 12b, and 12c also shown in FIG. 1 are so roughened that the adhesion force associated with the optical fibre unit 1 and the pressure-resistant sheath 10 and the metal segments themselves 10a, 10b and 10c can be strengthened enough to protect the optical fibre unit. Water penetration which may occur in case of cable damages can also be prevented.

Abstract: In manufacturing a record matrix from a lacquer master having a sound groove in a surface thereof, a basic reduction solution containing borohydride compound and an acidic metal salt solution containing nickel salt, ammonium salt and lactic acid are sprayed against the surface of the master having the sound groove for effecting the electroless plating thereon of a nickel surface metal layer having thereon a projection strip coincident with the sound groove, a reinforcing layer is formed over the surface metal layer and its reinforcing layer are peeled off from the lacquer master along the boundary therebetween to provide the record matrix.