Abstract: An interchangeable optically readable storage disk has a substrate with a recording surface, and a cover thereon which may comprise a second substrate with a further recording layer. The disk includes a protecting arrangement at the circumference of the substrate, which includes a balancing arrangement. The balancing may be effected by apertures in the protecting arrangement, or balancing masses affixed thereto.

Abstract: A display device is provided having a layer of liquid crystal in a space enclosed by a rim of sealing material between two supporting plates. One supporting plate has a pattern of electrodes to be driven individually with supply electrodes and a number of external connection electrodes. The supply electrodes and connection electrodes are connected to at least one non-encapsulated IC-crystal provided on the one supporting plate. To provide protection for IC-crystal and to minimize a non-effective display area, the IC-crystals are accommodated in recesses of the rim of sealing material of the display device.

Abstract: In a display device having a liquid display medium, for example liquid crystal, the support plates must be kept accurately spaced apart. This is done by means of a monolayer of grains having a hard core and a thermoplastic envelope.