Cassette having an information disc

DETAILED DESCRIPTION It is an object of the invention to provide a cassette of which does not have the drawbacks of the prior-art cassettes, which combines an optimum rigidity of the housing with an optimum accessibility to the disc for different types of pick-ups, and which requires a minimal number of parts.
To this end the invention includes a first opening having a shape which is asymmetrical relative to a radius of the disc perpendicular to the front wall.
The use of an asymmetrical opening surprisingly results in the effect that both for asymmetrically shaped translating pick-ups and pivotal pick-ups adequate space for access to the disc surface can be obtained with an opening of a width which is slightly smaller than one third of the width of the cassette.
In apparatuses comprising a translating pick-up, the use of the cassette in accordance with the invention makes it necessary to allow for the orientation of the suspension construction of the pick-up relative to the disc radius.
In this respect the cassette imposes a limitation on the freedom in designing the apparatus.
However, in practice this limitation is not essential because for the construction of an apparatus it is irrelevant whether the suspension construction is situated at one side of the radius or at the other side of the radius.
It is merely required that the designer of the apparatus knows in advance at which side the suspension construction is to be arranged.
Pivotal type optical pick-ups are frequently used in optical audio-disc players which read Compact Discs (CDs).
Typically, the radius of the pivotal movement of the objective is approximately 30 mm.
CDs have a radius of 60 mm or 40 mm.
In cassettes in accordance with the invention containing discs of these diameters the customary pivotal devices can be employed without any problems.
A wide variety of embodiments are possible within the scope of the invention.
A preferred embodiment of a cassette in accordance with the invention includes a first main wall has a second opening for giving a drive spindle of a drive arrangement access to the centre of the disc