Abstract: Compositely micro-textured thin film, magnetic disc media, with methods and apparatus for producing such, which are characterized by the incorporation of a first stage of micro-texturing provided by etching of a disc substrate, with a second, disparate, micro-texturing stage depositing rounded globules of eutectic alloy on the etched substrate.

Abstract: Write-once and erasable recording media (1) and a method of manufacturing such media. According to one aspect of the invention, one or more active layers (26, 30) of the optical data storage medium is formed by spin-on techniques. According to this aspect of the invention, the material used in forming the active layer is formed before the formation of the center aperture (4) in the optical disc. This aspect of the invention provides a substantially smaller "wedge" than prior methods. According to one preferred aspect of the invention, tracking grooves (24) in a flexible sheet (22) are bonded to a substantially rigid substrate (18). The sheet is bound to the substrate such that the tracking marks are directed away from the substrate. The active layers of an optical recording media are then formed on the sheet by, for example, spin-on techniques.

Abstract: An optical storage medium is disclosed. In general, the storage medium includes a substrate, with a first, expansion layer, a second, reflective layer bonded to the first layer, and a third, retention layer bonded to the second layer, opposite the first layer. An opto-electronic system for recording data is also disclosed, along with a method of manufacture of the storage medium.

Abstract: A method and apparatus for recording and reading both permanently stored information and user-supplied information on an optical disk are disclosed. The optical disk is provided with permanent information via pits in a substrate of the disk. User-supplied information is recorded in an expansion/retention layer adjacent the substrate. The permanent and user-supplied information may be read via laser beams having unequal wavelengths.

Abstract: A method of achieving a bulk erasure of a dye polymer optical storage media which includes a substrate, an expansion layer, and a retention layer. The optical storage media is placed into a temperature controlled environment in which the temperature is increased at a first prescribed rate to a prescribed temperature exceeding the glass transition temperature of the retention layer of the media. Above the glass transition temperature, the retention layer is transformed from a glass-like state to a viscoelastic state. While in the viscoelastic state, the retention layer shape conforms to the expansion layer to achieve the unrecorded media configuration (i.e. flat). The temperature of the controlled environment is maintained at the prescribed temperature for a specified period of time to achieve the bulk erasure, then reduced at a second prescribed rate. By controlling the prescribed temperature and specified time period, the media is erased in bulk providing an unrecorded media ready for use.

Abstract: An optical storage medium is disclosed. In a preferred embodiment a substrate is provided with an expansion layer. A retention layer is provided opposite the substrate. A liquid reflective layer is provided adjacent the retention layer, either adjacent to or opposite the expansion layer. The reflective layer is enclosed by a protective layer. Improved expansion and retention layers are also disclosed.

Abstract: An improvement is disclosed relating to optical data storage media having two thermo-optically active layers which absorb light at distinct wavelengths--an expansion layer in which data appear as bulges formed upon the absorption of light, and a retention layer which fixes such bulges in place until it is selectively heated to a rubbery state permitting relaxation of the expansion layer and the consequent disappearance of the bulges. In accordance with the improvement, the retention layer is modified so that it absorbs a controlled amount of light at the wavelength which is absorbed by the expansion layer, with the result that it absorbs light at both wavelengths rather than just one. Direct heating of both layers by light absorption during recordation, and accordingly a faster recordation response, are thus achieved.

Abstract: Recordable/erasable optical storage media are disclosed. More particularly, it provides a method and apparatus for recording and erasing information on an optical storage medium. The medium of the present invention generally includes a rigid substrate and an active region or layer adjacent to the substrate. The active region is a single polymer layer that functions as both an expansion layer and a retention layer. Reflective and protective layers may or may not be present. Additionally, methods for writing and erasing on these media are described.

Abstract: An optical storage medium is disclosed. In general, the storage medium includes a substrate, with a first, expansion layer, a second, reflective layer bonded to the first layer, and a third, retention layer bonded to the second layer, opposite the first layer. An opto-electronic system for recording data is also disclosed, along with a method of manufacture of the storage medium.

Abstract: An optical storage medium is disclosed. In general, the storage medium includes a substrate, with a first, expansion layer, a second, reflective layer bonded to the first layer, and a third, retention layer bonded to the second layer, opposite the first layer. An opto-electronic system for recording data is also disclosed, along with a method of manufacture of the storage medium.

Abstract: An optical storage medium is disclosed. In general, the storage medium includes a substrate, with a first, expansion layer, a second, reflective layer bonded to the first layer, and a third, retention layer bonded to the second layer, opposite the first layer. An opto-electronic system for recording data is also disclosed, along with a method of manufacture of the storage medium.

Abstract: An optical storage medium is disclosed. In general, the storage medium includes a substrate, with a first, expansion layer, a second, reflective layer bonded to the first layer, and a third, retention layer bonded to the second layer, opposite the first layer. An opto-electronic system for recording data is also disclosed, along with a method of manufacture of the storage medium.

Abstract: The entire data content of a thermally erasable optical memory medium is erased simultaneously by irradiating the entire signal-retaining layer of the medium with light in such a manner that the signal-retaining layer is preferentially heated over other layers in the medium, particularly other thermo-optically active layers if any are present. The irradiation is most effectively achieved with a flash of light at high intensity and short duration.

Abstract: An improvement is disclosed relating to optical data storage media having two thermo-optically active layers which absorb light at distinct wavelengths and expansion layer in which data appear as bulges formed upon the absorption of light, and a retention layer which fixes such bulges inplace until it is selectively heated to a rubbery state permitting relaxation of the expansion layer and the consequent disappearance of the bulges. In accordance with the improvement, the retention layer is modified so that it absorbs a controlled amount of light at the wavelength which is absorbed by the expansion layer, with the result that it absorbs light at both wavelengths rather than just one. Direct heating of both layers by light absorption during recordation, and accordingly a faster recordation response, are thus achieved.

Abstract: Optical data storage media of various technologies, including those with multiple layers of varying absorptivities of light as well as those which are grooved to facilitate tracking, are improved by combining the absorptivity differences with height variations in the interface between the layers (and thereby the relative thicknesses of the layers). The result is a means of varying in a spatial manner in the media themselves the rate at which such media absorb energy. This offers a variety of benefits in both recordation and reading, including helping to focus the heat generated by incident recording beams, increasing tracking sensitivity for both recordation and reading, and preformatting the media as a guide for both recordation and reading.

Abstract: A cleaning apparatus for the capstan of a VHS-type video cassette player/recorder is disclosed which contains an absorbent pad in a cartridge which is both insertable and removable through one of the broad side walls of the cleaning cassette. A pin projecting from the cartridge and extending through an access hole in the opposite wall permits easy manual ejection of the cartridge when the absorbent pad needs cleaning or replacement.