| 摘要 |
PURPOSE:To double-write information to be recorded simultaneously, and to back up information in a short time by forming two layers of recording layers onto a substrate and forming an optical isolating layer, through which incident light is transmitted and which reflects it, between the recording layers. CONSTITUTION:A first recording film 1b has light-transmitting properties, and laser beams from an optical head 5 focussed by an objective 6 oppositely mounted to the top face of a substrate 1a are transmitted. A light-transmitting first intermediate film 1d1, a semitransparent optical isolating film 1e, through which laser beams are transmitted by half and which reflects them by half, and a second intermediate film 1d2 are formed on the underside of the first recording film 1b1 in the order. A second recording film 1b2 and a protective film 1c are shaped on the underside of the second intermediate film 1d2 in the order. Consequently, recording is enabled simultaneously to the two recording films 1b1, 1b2 by one laser beams, thus allowing back-up even when information is not recorded respectively. Accordingly, even when information recording on the second recording film 1b2 is dissipated for any cause, dissipated information can be regenerated by regenerating information recorded to the first recording film 1b1. |
