A recording layer formed between a first substrate and a second substrate. The recording layer has recording surfaces on both sides thereof. A reflecting film is formed on an outside surface of the first substrate. The first and second substrates adjacent the recording layer have different refractive...http://www.google.com.au/patents/US6324155?utm_source=gb-gplus-sharePatent US6324155 - Optical information recording medium with flat reflecting film and reading system for reading information recorded thereon
