1. Field of the Invention
This invention relates to tape cassettes and video recording and reproducing systems using the same.
2. Description of the Prior Art
Development of a video recording and reproducing system comprising in combination a cassette type video tape and a VTR apparatus (Video Tape Recording Apparatus) has been recently particularly intense, and today such systems find wide acceptance in private homes. In the background of this development, we can get a glance into the efforts of the industry to achieve a great increase in the recording capacity for the video signals while still maintaining the bulk and size of the system and particularly the VTR apparatus at a minimum. Since, particularly in the case of the cassette type VTR apparatus, its dimensions largely depend upon the size of the tape cassette used therein, the larger the size of the tape cassette, the larger is the size of the VTR apparatus using such cassette. Further, since, therefore, the tape cassette could not be increased in size much more, the amount of tape accommodated in the cassette was necessarily limited which hindered increasing the recording capacity of video signals. Such drawback has, however, been overcome to some extent by reducing the thickness of magnetic tape due to the recent advance in the magnetic technology and by increasing the recording density by employing the guard bandless-azimuth recording method which is made possible by the improvement in the performance of magnetic material for the tape. As a result, the size of the tape cassette is reduced, and, therefore, the bulk and size of the VTR apparatus also is reduced, while nevertheless permitting the recording capacity of the video signals to be increased (elongation of picture recording time).
Of the video recording and reproducing systems of this character, there is a portable VTR system comprising, in combination, a portable TV (Television) camera and a portable VTR apparatus. Since this portable system has much importance particularly to the convenience in carrying, there is a stronger demand for further reducing the bulk and size of the VTR apparatus, and, therefore, there is also a stronger demand for reducing the size of the tape cassette. On the other hand, as has been mentioned above, although it is said that it is made possible to achieve a reduction in the size of the tape cassette by employing the thinner magnetic tape and the guard bandless-azimuth recording method, with the consideration of it as applied particularly to the portable system of the character described above in mind, the presently available tape cassette is still much too large and such circumstance makes it difficult to achieve a desired reduction in the bulk and size of the portable VTR apparatus. That is, if the emphasis is laid only on the reduction of the size of the VTR apparatus, it will be achieved by reducing the size of the tape cassette. This leads, however, to reduce the amount of tape accommodated in the cassette, thereby giving an alternate drawback that the total capacity of recording video signals is largely reduced.
Again, aside from the foregoing, although it is said that the increase in the video signal recording capacity is made possible by the reduction of the thickness of the magnetic tape and by the use of the guard bandless-azimuth recording method despite the reduction of the size of the cassette, as has been mentioned above, this trend of reducing the size of the tape cassette and of increasing the recording capacity is necessarily limited, and therefore, there remains room for so much improvement as desired with respect to a further minimization of the size of the tape cassette and a further increase in the recording capacity.