(54) A TAPE CASSETTE SYSTEM FOR THEREPRODUCTION OF VIDEO INFORMATION(71) We, ROBERT BOSCH GMBH, of Robert-Bosch-Strasse 7, 6100 Darmstadt,Federal Republic of Germany, a GermanCompany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:This invention relates to a tape cassette system for the continuous reproduction of video information stored upon magnetic tape in a plurality of cassettes.
A known system of this kind comprises a number of cassettes in an endless arrangement and two similar playback devices, the cassettes being alternately delivered to the devices for the purpose of playback and subsequent rewinding. However, this known cassette system has the disadvantage that on account of the necessity for rewinding the tape upon the playback device, the length of tape within the cassettes, and consequently the maximum time period available for reproduction from a single cassette, must in practice be limited.
Moreover, even if the entire length of tape in a cassette is not reproduced in any particular case, the minimum time period for the reproduction from the cassette must be at least as long as the cassette changeover time (including the necessary rewinding) in respect of the other playback device newly to be charged with the tape.
In the periodical "Fernseh-und Kinotechnik" No. 11/1976 there is disclosed a further cassette system for the reproduction of video information. wherein the cassettes are arranged in a rotating holder device, and two tape drive devices can call-up and play back the cassettes from the holder device in a desired sequence. The system has the same disadvantages as the previously de scribed known cassette system; that is. upon a certain playback time for each cassette being exceeded. the rewind time becomes so great that the rewinding operation must be performed manually outside the machine.
According to the present invention there is provided a cassette system for the continuous reproduction of video information stored upon magnetic tape in a plurality of cassettes, comprising an endless track for accommodating a predetermined number of said cassettes, the cassettes being displaceable around the track, a plurality of cassette playback devices arranged at respective locations adjacent the endless track, and a respective rewinding device associated with but separate from each playback device for rewinding the magnetic tape which has been played back in that playback device, the arrangement being such that a selected cassette may be brought adjacent a selected playback device by displacement of the cassettes around the track and then directly transferred from the track to the selected playback device, the selected cassette being transferred back to the track after playback of at least a selected part of the tape therein via the respective rewinding device whereby a fresh cassette can be transferred to the selected playback device while the previous cassette is being rewound.
The cassette system according to the present invention has the advantage that by separating the playback and rewinding devices it avoids to a greater extent than heretofore the restrictions appertaining to the minimum duration between switching from one cassette to another and the maximum duration for the individual contribution from each cassette.
In a preferred embodiment of the invention it is of particular advantage that each playback device is also capable of recording so that during the reproduction of information stored in one cassette. information can be newly recorded using one of the otherwise vacant playback devices.
An embodiment of the invention will now be described with reference to the accom i,anying drawing, wherein:Figure 1 is a schematic front elevation of an embodiment of a cassette system accord ing to the invention,Figure 2 shows the same cassette system in plan view.
In Figure 1 a finite number of video magnetic tape cassettes, some of which are iXdicåted by the reference characters 5 to 11 and 36 td 40, is so arranged updn an endless track 1 that, within the extent of the vertical portions of the endless track, each may be withdrawn out of the track towards either side thereof in the plane of the drawing.
Between the vertical portions of the endless track 1 there is arranged a first tape drive device for recording and reproduction 101, and associated with and below the latter there is arranged a separate rewinding device 102. At the same height as the tape drive device l01 there are arranged on the outside of the endless track 1 two further tape drive devices 103 and 105 also having respective separate rewinding devices 104 and 106 associated therewith. The cassettes are displaceable around the track, and when a cassette is brought to a position laterally adjacent an unoccupied device 101, 103 or 105 it can be transferred from the track directly to such', device.
In Figure 2 there is shown in plan view the positions with respect to the endless track 1 of the tape drive devices 101, 103 and 105 and the respective rewinding devices 102, 104 and 106 with cassettes accommodated therein.
In the operation of the cassette system illustrated, selected cassettes situated upon the endless track 1 are delivered in a preselected sequence by an automatic control arrangement (not shown) directly to vacant ones of the tape drive devices 101, 103 and 105. For this purpose the cassettes are so arranged that they may, in each case, be withdrawn in either direction from the track 1, and the control arrangement ensures that each cassette intended for a playback operation is delivered to the nearest unoccupied playback device as measured along the length of the track. Accordingly the cassettes are displaceable upon the track 1 selectively either in the clockwise direction or in the counterclockwise direction. In order that the control arrangement shall be able to distinguish one cassette from another, each cassette bears a respective characteristic identifying mark by which the position of the cassette within the track can be determined by the control arrangement.
After the reproduction from all or a selected portion of the tape in a cassette has been completed in one of the playback devices l()l, 103 or 105. the cassette is immediately transported to the respective rewinding device 102, 104 or 106 associated with the playback device hosed in the reproduction from that cassette, and is rewound therein into the starting position. During this rewinding operation it is possible for the emptyplayback device to be recharged with a new cassette from the track, so that rio time is lost in the rewinding operation.
After the compietion of the rewinding operation, the endless track 1 is so controlled by the control arrangèment that the nearest unoccupied cassette position (as measured along the length of the track) is brought adjacent the rewinding devide for transfer of the cassette to the track.
In consequence of the arrangement of the rewinding devices 102, 104 and 106 along the endless track 1, separate from their associated tape drive devices, it is no longer necessary that the minimum playing time of the magnetic tape in each cassette shall take into account the rewind time when changing cassettes in respect of another tape drive device, and furthermore the playing times of each tape need not be limited to a maximum duration of a few minutes in order to avoid the rewinding operation overtaxing' the capacity of the playback device.
The described cassette system is therefore able to store on the tapes a large number of program contributio'ns and, substantially without any limitations being imposed upon the duration of the individual contributions of the tapes, to play them back (each in full or part) without any interval in accordance with a preselected sequence under the control of the control arrangement to provide a complete programme for viewing.
Furthermore, since at least one, and preferably all, of the tape drive devices 101, 103 and 105 are capable of recording as well as reproducing, it is possible that during the reproduction from one cassette on a first tape drive device, fresh information can be recorded on another cassette using one of the otherwise vacant tape drive devices.
Finally, although the preceding description has described the devices 102, 104 and 106 as rewinding devices, it is of advantage that at least one, and preferably all, of the device5 are also capable of winding-on to a selectable extent. Thus it is possible that one or more of the cassettes may have several programme contributions distributed arbitrarily thereon. The devices 102. 104 and 106 can then be used, when necessary and under the control of the control arrangement, to wind on each such cassette after a particular programme contribution thereof has been reproduced to the start of the next programme contribution which will be required of that cassette in the next reproduction-opera- tion therefrom. Also. when used in the rewinding mode. it is not necessary that the tape be fully rewound if the next program me contribution from the relevant cassette does not start at the beginning of the tape.
It is to be understood that although the embodiment described above has only two playback devices on the outside of the track and only a single one such device on the inside of the track, the number of such devices both inside and outside the track may be increased if desired.
WHAT WE CLAIM IS:1. A cassette system for the continuous reproduction of video information stored upon magnetic tape in a plurality of cassettes, comprising an endless track for accommodating a predetermined number of said cassettes, the cassettes being displaceable around the track, a plurality of cassette playback devices arranged at respective locations adjacent the endless track, and a respective rewinding device associated with but separate from each playback device for rewinding the magnetic tape which has been played back in that playback device, the arrangement being such that a selected cassette may be brought adjacent a selected playback device by displacement of the cassettes around the track and then directly transferred from the track to the selected playback device, the selected cassette being transferred back to the track after playback of at least a selected part of the tape therein via the respective rewinding device whereby a fresh cassette can be transferred to the selected playback device while the previous cassette is being rewound.
2. A cassette system as claimed in claim 1, wherein at least two playback devices are provided on the outside of the endless track.
3. A cassette system as claimed in claim 1 or 2, wherein at least one playback device is provided on the inside of the endless track.
4. A cassette system as claimed in any preceding claim, wherein the cassettes are displaceable selectively in either direction along the track and a control arrangement automatically provides that each cassette intended for playback is brought to the nearest vacant playback device.
5. A cassette system as claimed in claim 4. wherein after a rewinding operation the control arrangement further provides that each cassette is introduced into the nearest unoccupied position of the endless track.
6. A cassette system as claimed in claim 4 or 5, wherein each cassette bears a respective characteristic identifying means by which the position of the cassette within the track can be determined by the control arrangement.
7. A cassette system as claimed in any preceding claim, wherein at least one of the playback devices is also capable of recording information upon the magnetic tape in a cassette delivered thereto.
8. A cassette system as claimed in any preceding claim, wherein at least one of the rewinding devices is also capable of winding-on to a selectable extent the tape in a cassette delivered thereto.
9. A cassette system substantially as described herein with reference to the accompanying drawing.
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