摘要:
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.
摘要:
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.
摘要:
An optical recording medium has a substrate having an annular grooves, a recording layer including an organic coloring matter and formed on the substrate, and a metallic reflection layer. The recording layer has a thickness so as to have an absorbance between 0.65 and 0.75. Information is recorded in the recording layer by a laser beam having a wavelength between 600 and 700 nm, using an objective lens having a numerical aperture between 0.55 and 0.70.
摘要:
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.
摘要:
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.
摘要:
A substrate has a disk-like shape with a thickness of about 1.2 mm, and a diameter of D1, and further a central hole of diameter D2. A signal recording layer is formed on the substrate, and further a transparent sheet, through which a laser beam passes to record and reproduce information, is stacked up on the signal recording layer. The transparent sheet has a circular shape with a diameter d1, and the central hole thereof has a diameter d2. In a size-relationship of these diameters, d1 is formed to be smaller than D1, and d2 is formed to be larger than D2. In the other words, the transparent sheet, which is attached on the substrate so as to cover the signal recording layer, has outer and inner ends being positioned inside both an outer peripheral end of the substrate and a peripheral end of the central hole, so that a damage such as tearing off the peripheral end of the transparent sheet can be avoided since the peripheral end is inwardly apart from a finger-touch-area.
摘要:
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.