| 摘要 |
PURPOSE:To reduce cracking tracking channel sections and information pit sections to be transferred to a base by forming the shape of the side surface of a projected section of recessed and projected preformat patterns on the surface of a mold for cast molding inclined outwardly in the depth direction. CONSTITUTION:Metal such as chrome or the like is adhered on a glass plate by means of deposition or the like, on which a photoresistor is formed and exposed, and metal patterns of recessed and projected preformat patterns are provided on the glass plate. Both of side surfaces 3 of patterns 2 of a projected section and a plane surface 4 of a glass plate 1 are included by the angle theta. Thus, the cracking on tracking channel sections and information pit sections of a base can be controlled by cast molding liquid resin by means of said mold 5 for cast molding and making an angle theta formed by the plane surface 4 of the glass plate 1, and a side surface 3 of the patterns 2 of the projected section 60 deg. or less, normally 20 deg.-60 deg.. |
