Optical read-write system for disc memories - has disc sandwiched between covers to prevent errors due to dust particles or surface scratches (NL 20.12.77)

摘要

A disc memory system based upon micron sized elements is constructed to avoid errors due to dust particles or scratches. The recording disc (2) is sandwiched between a transparent glass top plate (1) and a bottom plate (3). The bottom plate is located against sealing rings (4) that provides an enclosed volume that may be filled with an inert gas when the recording disc is metallic. This prevents corrosion. The reading system consists of a laser source (8), modulator (9) and focussing lens (10).