1. Field of the Invention
This invention relates to a tape cassette such as a video cassette which accommodates a record media, for instance, a tape-like media in a casing.
2. Discussion of Background
Generally speaking, an information media of a video cassette is apt to capture dirt and dust in handling, which may damage the information media. Therefore, the information media is protected by being accommodated in a synthetic resin casing. This case is constructed by fastener-fixing or melt-bonding an upper half casing and a lower half casing at a plurality of fixing portions, which are formed by an ABS resin (acrylonitrile butadiene styrene copolymer resin), a PS resin (polystyrene species resin), a PP resin (polypropylene species resin) or the like. The upper half casing and the lower half casing are integrated by fixing opposedly protruded projections respectively provided on the upper and lower half casings, by screws or by ultrasonic melt bonding and the like. The fixing of the projections are performed at positions which are as proximate as possible to the outer peripheral portion, other than at the central portion thereof, to prevent deformation and the like.
As shown in FIGS. 3 and 4, the fixing portions of the upper and lower half casings are disposed as proximate as possible to the outer peripheral portion, other than at the central portion, at least one of which is a fixing portion P.sub.1 of which position is inside of a rotatable front lid 3. Protrusions 1.sub.1 and 2.sub.1 are opposely provided on the inner faces of the upper half casing 1 and the lower half casing 2, at these fixing portions P and P.sub.1. However, the following problems are caused in the fixing operation at the fixing portion P.sub.1 of which position is inside the position of the front lid 3, which are compounded by the integration cycle.
(1) In case of the fastening by screws, a failure in fixing such as the slackening of a screw, destruction of a screw ridge or the like is caused by a clearance C between the upper half casing 1 and the front lid 3.
(2) In case of the fixing by the ultrasonic melt-bonding, the ultrasonic vibration during the melt-bonding process transmitted to the front lid 3, the front lid 3 and the upper half casing 1 are melted and bonded together, and the rotating function of the front lid 3 is in failure.