Pioneer Electronic Corporation

Pioneer Video Corporation

Shinichi Hanzawa

Haruhisa Maruyama

Masaaki Motokawa

Masahide Itoigawa

Yoshitaka Nonaka

Mitsuhiko Sasano

Junichi Watanabe

Kenji Kamimura

Yoshikazu Hirai

A disc substrate inject-molded comprises; a first circular surface having an inner non-data region formed around a center hole thereof and an outer data region formed around the non-data region; a second circular flat surface opposite and parallel to the first circular surface; and a ring shaped stack-rib formed on the non-data region.

Disc substrate used for an optical disc and a molding die for molding

An optical disc has a pair of light-transmissible circular substrates each having an inner non-data region disposed around a center hole thereof, a data region disposed around the inter non-data region for bearing signals corresponding to information to be recorded and an outer non-data region disposed around the data region which are formed on a major surface of the substrate. The optical disc has a reflective layer formed on the data region and a protective layer made of an ultraviolet ray setting resin containing metal ions formed on the reflective layer. The optical disc has an adhesive layer made of an adhesive composition containing an ultraviolet ray setting component and an anaerobic hardening component disposed between the protective layers of the circular substrates for adhering the circular substrates.

Optical disc and method for manufacturing the same

In order to provide a laminated optical disc having a sufficient display portion and a reliable print display, a pair of disc substrates are bonded together to form an optical disc, in which one disc substrate is colored and contents of recorded matters are displayed on the surface thereof so as to eliminate the ground solid print layer for the print display layer and to avoid deformation or warping of the disc.

Laminated optical discs

A laminate optical disc which has excellent heat resistance and also has sufficient bond strength. Radiation-curing adhesive layers are formed on a pair of transparent base plates excluding the outermost circumferential portions, respectively, and an ultraviolet-curing resin is applied to the outermost circumferential portion. Then, the pair of transparent base plates are bonded together by the radiation-curing adhesive layers, and also ultraviolet light is irradiated to the ultraviolet-curing resin to fix the base plates firmly to each other along the outermost circumferential portions. In a process for producing a laminate optical disc, radiation-curing adhesive layers are formed respectively on a pair of transparent base plates, and then irradiated with a radiation excluding at least the outermost circumferential portion to be tackified. After the thus treated base plates are bonded together by the radiation-curing adhesive layers, the outermost circumferential portions of these layers are irradiated until they lose tackiness.

Process of reproducing optical discs and optical discs produced by the

An optical pickup for emitting a laser beam is provided for reading data recorded on an optical disc. The axis of the laser beam is tilted at a skew angle from a perpendicular line to the surface of the disc. Error rate in reproduced data read out by the pickup is determined, and an inferior disc having a rare error rate is eliminated.

Growing community of inventors

Yamanashi, Japan

Shinichi Hanzawa