Optical disk with textured edge

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.

1 - 27 . (canceled) 
     
     
         28 . An optical recording medium comprising:
 a substrate including a textured side surface at an outer diameter edge of the substrate: and   a protective coating flowed over the textured side surface at the outer diameter edge of the substrate, wherein   said textured side surface has a texture of No. 3 or higher number according to the SPI-SPE standard.   
     
     
         29 . The optical recording medium of  claim 28 , wherein
 the substrate comprises plastic that has been heated to a molten state and flowed into a mold, and   the textured side surface having the texture of No. 3 or higher number according to the SPI-SPE standard is formed at the outer diameter edge of the substrate by contacting molten plastic with a textured surface of a molding element of the mold.   
     
     
         30 . The optical recording medium of  claim 29  wherein the textured surface of the molding element has a texture of No. 3 or higher number according to the SPI-SPE standard. 
     
     
         31 . The optical recording medium claim  9 , wherein the textured surface of the molding element is oriented along a parting line of the mold and the textured side surface at the outer diameter edge of the substrate is configured to allow removal of the substrate from the mold once parable molding element of mold is separated from the mold along the parting 
     
     
         32 . The optical recording medium of  claim 31  wherein
 the substrate further comprises a second textured surface portion adjacent to the textured side surface, the second textured surface portion being formed by contacting the molten plastic with a second textured portion of a molding element of the mold, and 
 the second textured portion of the molding element is not oriented along the parting line of the mold. 
 
     
     
         33 . The optical disc of  claim 28 , wherein said textured side surface at the outer diameter edge of the substrate has a texture of No. 5 or higher number according to the SPI-SPE standard. 
     
     
         34 . The optical disc of  claim 28 , wherein said textured side surface at the outer diameter edge of the substrate has a texture of No. 3 according to the SPI-SPE standard. 
     
     
         35 . The optical disc of  claim 28 , wherein said textured side surface at the outer diameter edge of the substrate has a texture of No. 5 according to the SPI-SPE standard. 
     
     
         36 . The optical recording medium of  claim 28 , wherein the protective coating adheres securely to the textured surface at the outer diameter edge to prevent seepage of moisture into the optical recording medium through the outer diameter edge surface 
     
     
         37 . The optical recording medium of  claim 28 , wherein the substrate includes two or more textured substrate surfaces at the outer diameter edge, and the protective coating adheres to the two or more textured substrate surfaces. 
     
     
         38 . An optical recording medium comprising:
 a substrate of plastic having a texture of No. 3 or higher number according to the SPI-SPE standard pressed in a side surface of the substrate at an outer diameter edge of the substrate, the texture being impressed by a textured surface of a textured molding element contacting the plastic of the substrate at a time when the plastic of the substrate is heated to a temperature at which the plastic of the substrate is molten; and   a protective coating flowed over the textured side surface at the outer diameter edge of the substrate.   
     
     
         39 . The optical recording medium of  claim 38  wherein the textured surface of the molding element has a texture of No. 3 or higher number according to the SPI-SPE standard. 
     
     
         40 . An optical recording medium comprising:
 a substrate formed n a cavity of a mold, the substrate having a texture of No. 3 or a higher number according to the SPI-SPE standard impressed in a side surface of the substrate at an outer diameter edge of the substrate; and   a protective coating flowed over the textured side surface at the outer diameter edge of the substrate, wherein   the texture impressed in the side surface of the substrate at an outer diameter edge of the substrate is impressed by a surface of the cavity to which a texture has been applied that is oriented along a parting line of the mold and   the substrate is configured to be removable from the mold when a separable molding element of the mold is separated from the mold along the parting line.   
     
     
         41 . The optical recording medium of  claim 40  wherein the surface of the cavity to which a texture has been applied has a texture of No. 3 or higher number according to the SPI-SPE standard.