Abstract: Optical information carrier comprising an optically transparent layer and a reflective layer adjacent to each other, and the interface between the layers comprises an optically readable information structure containing alternate areas with such different properties that a scanning light beam is modulated in correspondence with the information present in the structure. In the interface between the optically transparent layer, and the surface of the reflective layer, multiple gas-filled interconnected buffer spaces are provided at positions distributed over the interface, so as to provide for vapor pressure equalization across the carrier structure to maintain its flat shape.

Abstract: Optical information carrier comprising an optical transparent layer and a reflective layer adjacent to each other whereby the interface comprises an optically readable information structure containing alternate areas with such different properties, so that a scanning light beam is modulated in correspondence with the information present in said structure. Between the surface of the transparent layer and the surface of the reflective layer one or more gas-filled interconnected buffer spaces are realized at positions distributed over the interface between said layers.

Abstract: Optical information carrier comprising an optically transparent layer and a reflective layer adjacent to each other whereby the interface comprises an optically readable information structure containing alternate areas with such different properties, so that a scanning light beam is modulated in correspondence with the information present in said structure. Between the surface of optically transparent layer and the surface of the reflective layer, one or more gas-filled interconnected buffer spaces are provided at positions described over the interface between the layers, and an excavation is provided at the edge of the carrier.

Abstract: Cassette containing a recording carrier in tape form, and including means for transporting the recording carrier tape along an information transfer member forming part of the means for reading and/or writing and/or erasing the recording carrier tape. The cassette has an enclosure of hermetically sealed construction, and is filled with an inert low pressure gas which does not react chemically with the surface of the tape or with the surface of the tape guide means, if such means exists, such as hydrogen or helium gas at a pressure below 0.05 MPa.

Abstract: Device for guiding an information carrier which is in tape form and moves between two reels. The device is situated in the path of tape transport between the two reels and embodied as a slidable guide member along which the tape is moved with a certain tape tension. The guide member is a non-rotatable sliding member adapted to oscillate in a direction at right angles to the local direction of movement of the tape, with a maximum acceleration which is at least a few times greater than the transverse component of the tape tension divided by the mass of that part of the tape which is affected by the sliding member.

Abstract: Method for reproducing relief structures onto a substrate, whereby between a die surface comprising holes or protuberances corresponding to the negative shape of the relief to be reproduced, and a substrate a hardenable liquid is deposited. After depositing the die surface and the substrate are at least locally forced together whereby the respective section of the die surface does not move in relation to the substrate in any other direction than perpendicular to the contact surface. During the following hardening of said liquid there is no mutual movement between the die surface and the substrate both of which remain forced together with a pressure which is smaller than the pressure during the initial pressing stage. The substrate and the die surface are separated after the liquid is hardened.