Abstract: Debris suppression is effected in a sealed disk unit, of the kind having a generally enclosed record element/cover sheet inter-space, by controlling the temperature gradient across the inter-space so that thermophoretic forces, exerted by air molecules, drive ablative debris particles toward the cover sheet.

Abstract: Optical disc write/read apparatus and systems of the type having a flexible record disc and turntable which interface in a manner forming a generally enclosed space between record portions of the disc and opposing turntable portions is provided with inner and outer ventilation means which effect a continuous, controlled air flow through said space during write/read operations.

Abstract: High information density retrieval method and system which employ the scanning of an optical disk, having a thermally-deformable record layer overlying a reflective support, with a read light beam. The optical disk tracks contain information in the form of variable-width, approximately 0.5.pi. phase-depth, pit regions interleaved between nominal thickness land regions. The pits have varying track lengths within a pit-length range constituting a disk fractional band-width of greater than 4.0 and read light reflected from the tracks is split-detected. The split-detected, electrical analog signal is peak-detected to reconstruct recorded digital data on the disk.

Abstract: A recording element adapted for real-time writing and reading with light of a single given wave-length utilizes a recording stratum, including a heat-deformable dye-binder layer, overlying a reflective support and is characterized by the dye-binder layer having optical constants such that its reflectance versus thickness variation curve has a first reflectance minimum having a high depth of modulation and the recording stratum having a nominal thickness sufficiently greater than the thickness corresponding to the first reflectance minimum to effect reflection of a significant portion of light of such given wavelength.