Optical information recording disc with differing front and rear sides

摘要

The first substrate (1) has a first information recording surface (2), storing an information that can be reproduced, and provided with cavities or pits in which the information can be recorded in spiral form or in the form of concentric circles, on the front side of disc. This first recording surface is coated with a first reflecting layer (3) for reproducing the information, and is then covered with a first protecting layer (4) to prevent any damage from dirt and shocks. There is a second substrate (5), a second recording surface (6), a second reflecting layer (7), and a second protecting layer, on the other side or back of disc. The sides have different transmission spectra, due to the different composition of the substrates.