Abstract: A method for producing optical discs is provided. A substrate for an optical disc is formed by utilizing a molding process. A textured surface is formed at an outer diameter edge of the substrate. A protective coating is applied to cover the textured surface at the outer diameter edge. The protective coating adheres securely to the textured surface at the outer diameter edge to prevent seepage of moisture into the optical disc through the outer diameter edge surface. Thus, an improved optical disc which avoids moisture-caused warpage, corrosion and/or oxidation can be formed.

Abstract: A method for producing optical discs is provided. A substrate for an optical disc is formed by utilizing a molding process. A textured surface is formed at an outer diameter edge of the substrate. A protective coating is applied to cover the textured surface at the outer diameter edge. The protective coating adheres securely to the textured surface at the outer diameter edge to prevent seepage of moisture into the optical disc through the outer diameter edge surface. Thus, an improved optical disc which avoids moisture-caused warpage, corrosion and/or oxidation can be formed.

Abstract: A method for producing optical discs is provided. A substrate for an optical disc is formed by utilizing a molding process. A textured surface is formed at an outer diameter edge of the substrate. A protective coating is applied to cover the textured surface at the outer diameter edge. The protective coating adheres securely to the textured surface at the outer diameter edge to prevent seepage of moisture into the optical disc through the outer diameter edge surface. Thus, an improved optical disc which avoids moisture-caused warpage, corrosion and/or oxidation can be formed.

Abstract: A method and apparatus for vacuum assisted venting of an injection mold. The apparatus includes a main body structured to be mounted around an outer circumference of the injection mold and configured to facilitate application of a vacuum pressure therein. The method and apparatus are particularly directed towards preventing the accumulation of residual material inside an injection mold and reducing the frequency of disassembly and cleaning required for the injection mold.

Abstract: A method and apparatus for vacuum assisted venting of an injection mold. The apparatus includes a main body structured to be mounted around an outer circumference of the injection mold and configured to facilitate application of a vacuum pressure therein. The method and apparatus are particularly directed towards preventing the accumulation of residual material inside an injection mold and reducing the frequency of disassembly and cleaning required for the injection mold.

Abstract: A protective layer is applied to the surface of a compact disc precursor that must be protected from dust during manufacture. The layer is removable and preferably made of ethylene vinyl acetate.

Abstract: An in-line system for fabricating a double sided compact discs by bonding together an information bearing surface and another surface, has a prestressing station with means for deforming at least one of the surfaces in such away as to not disturb any of the data. It employs an adjustable spacer for maintaining an adjustable separation between symmetrical arcuate portions of the outer circumference of the information bearing surfaces in the bonding station. This adjustable spacer comprises two spacer arms that comprise wedge shaped portions for entry between the edges of said discs and maintaining a displacement of at least the outermost edges of said discs. There is also disc displacement means for bringing together the two information bearing surfaces by displacement of at least one of said information bearing surfaces orthogonal to the plane of the surfaces.

Abstract: Automatic process control of the optical disc bonding process is achieved by tacking the adhesive and deforming the composite prior to final bonding. A separator chuck is used to maintain the separation of the disc halves through tack curing and a disc deforming jig is used during final bonding to compensate for any tendency of the disc halves to deform during the bonding operation.

Abstract: Methods for bonding structurally asymmetrical or otherwise structurally dissimilar optical discs are provided. A bonded optical disc stack is formed from a first and a second optical disc by coating the back side of at least one of the optical discs with a light-curable bonding material and stacking the first and second optical discs back to back. The front side of the second optical disc is exposed to light for a first predetermined time period. The front sides of both the first and second optical discs are then exposed to light for a second predetermined time period. Finally, the front side of the first optical disc is exposed to light for a third predetermined time period. In this manner, when the second optical disc comprises program information and the first optical disc comprises a graphical image or other artwork, image pass-through due to simultaneous exposure and disc warpage due to one-sided exposure are significantly reduced.