Multilayer disc manufacturing apparatus, and disc bonding method

Abstract

There are provided a multilayer disc manufacturing apparatus and method, capable of computing a rotational eccentricity of a disc with no contact with the disc and a high accuracy, and producing the disc with lower costs without having to rotate the disc or perform any complicated operations. The multilayer disc manufacturing apparatus ( ) is for manufacturing a multilayer disc by bonding one disc ( ) to another disc ( ). The apparatus includes means for fixing, in place, one ( ) of the discs which form together a multilayer disc, means ( ) for projecting a light onto a boundary ( ) between an embossed signal recording area ( ) and non-signal recording area on the one disc ( ) fixed in place, means ( ) for capturing a return light from the boundary ( ) illuminated with the light projected from the light projecting means ( ), means ( ) for positioning the center of a signal recording area on the other disc ( ) and means ( ) for varying the position of the centering means ( ) in relation to the disc fixing means.