Abstract: A method of manufacturing an optical data storage medium, comprising at least one substrate (11) and a plurality of layers deposited on the substrate (11) is described. The medium includes at least one of a transparent spacer layer and transparent cover layer (12). The layer (12) is provided by applying a liquid onto the rotating substrate (11) and rotating the substrate (11) further in order to spread out the liquid into a layer substantially uniformly between an inner radius ri and an outer radius ro, and solidifying the liquid layer (12) by means of exposure to UV radiation. After applying the liquid onto the rotating substrate the liquid layer (12) is heated by heating means (14) in such a way that the temperature rise of the liquid layer (12) at ri has a value ?Tri, while the temperature rise of the liquid layer (12) between ri and ro gradually increases, and the temperature rise of the liquid layer (12) at ro has a value ?Tro>?Tri.

Abstract: A method of manufacturing an optical data storage medium, comprising at least one substrate (11) and a plurality of layers deposited on the substrate (11) is described. The medium includes at least one of a transparent spacer layer and transparent cover layer (12). The layer (12) is provided by applying a liquid onto the rotating substrate (11) and rotating the substrate (11) further in order to spread out the liquid into a layer substantially uniformly between an inner radius ri and an outer radius ro, and solidifying the liquid layer (12) by means of exposure to UV radiation. After applying the liquid onto the rotating substrate the liquid layer (12) is heated by heating means (14) in such a way that the temperature rise of the liquid layer (12) at ri has a value dTri, while the temperature rise of the liquid layer (12) between ri and ro gradually increases, and the temperature rise of the liquid layer (12) at ro has a value dTro>dTri.

Abstract: A method of manufacturing an optical storage medium is provided, which comprises at least a transparent spacer layer (22) or transparent cover layer. This layer is provided by spincoating a liquid layer (22) between an inner radius ri and outer radius ro and substantial solidification by means of exposure to e.g. UV-radiation. The solidification of the liquid (22) is started at ri at a moment in time defined as t=ti. The solidification of the liquid (22) at ro takes place at a moment in time defined as t=to and to=ti+d and d>1 s. The solidification of the liquid (22) between ri and ro takes place at a moment in time between ti and to. The advantage is that the radial thickness uniformity of the solidified liquid (22) is substantially improved and better than +/??m.

Abstract: The invention describes an optical data storage medium comprising a substrate (2), a spacer layer (5) and a cover layer (8). The medium comprises two information layers (3, 4) and (6, 7). The invention further describes methods of manufacturing such an information medium (1), which relate to the manner in which the information layers are provided with data patterns. The invention further discloses a method wherein an UV light (10)-transparent stamper (9) is used in combination with a photopolymerization lacquer and/or pressure-sensitive adhesives.

Abstract: A description is given of a method of manufacturing a stamper for use in the manufacture of Small Form Factor (SFF) optical data storage media. A conventional master plate (2) is provided with a series of areas with spiral- or concentric-shaped information tracks (3a-3h), having a relief structure, with the center of each area (3a-3h) being located outside the axis of rotation (9) of the master plate (2). This is done by using a conventional master recorder and a separate master plate support structure (1) without the necessity for complex movements of the master recorder writing head. The master plate (2) thus obtained is used to produce the stamper, containing a negative replica of the surface of the master plate (2).

Abstract: A magnetic device which can be driven by means of electromagnetic radiation and has a radiation-sensitive element consisting of cobalt-doped yttrium-iron garnet. Exposure to electromagnetic radiation produces a decrease of the magnetic permeability of the element which decrease is permanent until the element is demagnetized and occurs at temperatures from 77.degree. K to room temperature.

Abstract: A heating device formed as a double-wall tubular heat pipe with a closed annular space between outer and inner walls containing a vaporizable liquid heat-transporting medium, and a cylindrical bore defined within said inner tube as the heating space for objects to be heated, said annular space having end walls closing its ends, and means for transmitting heat through one of said end walls into said space.