GB2051454A - Cassette selection arrangement - Google Patents

Abstract

The arrangement which permits the successive playback of selected tape cassettes in a predetermined sequence comprises a magazine or store of tape cassettes assembled in the form of a planar matrix, and a gripper mechanism which in dependence upon previously specified and stored instructions automatically withdraws tape cassettes from the magazine and delivers them in succession to at least one playback device. Furthermore the system includes, for one or more similar playback devices, a driving mechanism including an intermittently operating gear, whereby the cassettes are successively brought into a condition of readiness and the tape loop associated with the cassette is threaded into the playback station. <IMAGE>

Description

SPECIFICATION Automatic multiple tape cassette system This invention relates to an automatic multiple tape cassette system, in particular of the kind comprising a plurality of tape cassettes accommodated in a magazine and means for the automatic transference of selected cassettes in the magazine to and from at least one tape playback device in a predetermined sequence.

Systems of the above kind are already known, for example in German published Patent Specification 20 36 44. In this known system the tape cassettes are arranged upstanding in star formation upon a rotary table and, by suitable angular movements of the rotary table, are selectively delivered to a play back station from which, after play back has been completed, they are returned to the rotary table. Furthermore, transporting devices for magnetic tape cassettes are known wherein the cassettes are carried, in the form of one or more endless series, on conveyor belts and are selectively taken to a playback station and after playback has been completed are returned to their respective positions in the endless series.

However, these known arrangements have the disadvantage that for the purpose of withdrawing the cassettes by hand (during replacement) or by purpose-built devices (during automatic operation) the tape cassettes must be transported to a predetermined withdrawal position, in which operation it is necessary that all of the cassettes which are arranged upon the same rotary table, or upon the same endless belt, must be moved together. This operation requires the movement of a large mass and is correspondingly time-consuming and wasteful of power. Furthermore the known arrangements have the disadvantage that access to the individual tape cassettes is complicated by the fact that there are always a number of cassettes which are head downwards and consequently titles are legible only with difficulty.

Accordingly, the present invention provides an automatic multiple tape cassette system comprising a plurality of tape cassettes accommodated in a magazine, and means for the automatic transference of selected cassettes in the magazine to and from at least one tape playback device in a predetermined sequence, wherein the tape cassettes are arranged in a planar matrix in the magazine.

In contrast to the above prior art, the system in accordance with the invention has the advantage that unrestricted manual access to the stored cassettes is always available. It is to be regarded as a further advantage that once an arrangement has been chosen for the cassettes in the storage magazine the cassettes may be left in that arrangement, thus providing for the attendant a system which is easily supervised and memorized. Of particular advantage of an embodiment of the invention is the fact that the number of stored cassettes is not dependent upon any strict limitation and that item sequence times are available which are substantially smaller than the rewind times for the played back cassette.

The embodiment of the invention to be described later is based upon the following considerations of a general nature regarding the desirable characteristics of an automatic multiple tape cassette system.

In the quadruplex technique it is known to use tape cassettes of three minute and six minute playing duration. The relatively long playing time of the professional BCN cassette gives rise to consideration of the use of automatic multiple cassette mechanisms in the running of programmes. The operating conditions depend to a large extent upon the wishes of the user whether it be for a commercial or non-commercial television station, or an instructional or educational exercise.A viable and flexible system must admit the following possibilities of use:~ (a) continuous reproduction, (b) continuous recording (c) parallel recording, (d) duplicating, (e) editing, (f) classification of programme material, and (g) random access to the programme store for (1) news items, (2) commercial spots, (3) editing, (4) assembling, (5) slide programmes with or without sound accompaniment, (6) programme preview, (7) station identification, and (8) interval fillers.

From these possible uses there arise the following system requirements: ~the identification of the cassette and its contents, ~the facility of programming for programme operation, ~the facility of programming for production operation, ~short item sequences, ~manual servicing for all use possibilities, ~capability of remote servicing.

These demands may be satisfied partly by mechanical and partly by electronic features.

The movement of the cassette along the path to be taken in transferring the cassette to and from the playback device, the threading and unthreading of the tape at the playback device, and the winding of the tape to its starting point each demand a certain time period, which can only be influenced within certain limits.

The item sequence time therefore depends essentially upon the number of playback de vices and the rewinding time for an item. It is known that cassettes, in contrast to cartridges, have the advantage that before being withdrawn from the playback device they do not need to be rewound. Consequently, if the number of the necessary cassettes is not greater than the number of cassette reception places in a multiple cassette machine, the rewinding time can be left out of consideration. This also applies even when in one or more cassettes there are items of long playing time. During this playing time it is in fact possible to reactivate for rewinding particular cassettes which have already been replaced after playback. This means that the number of playback devices determines the shortest item sequence time.If one furthermore takes into consideration the fact that continuous editing is possible only with at least two slave machines, then the basic equipment offered for a multiple cassette machine is a construction with two playback devices, which nevertheless is in practice designed with three playback devices, in which case readjustment can easily be made on the site.

Two playback devices will give minimum item sequences of about 12 sec and three playback devices will give sequence times of about 7 sec. Obviously this applies only for a plurality of short items in succession. If a short item is interposed between two longer ones the time can obviously be still shorter than 7 sec.

The relationships between the time cycles are represented in Fig. 9. The functions "select cassette", "insert cassette" and "file cas sette are assigned to the magazine, and all other functions are assigned to the playback devices. The critical path of this diagram is represented by the functions "record" and "reproduce", since the course of the horizontal line forming this part of the diagram cannot be interrupted by pauses. The loading of the three unoccupied playback devices proceeds relatively quickly, because as soon as the-first cassette has been inserted the cassette for the next playback device can be selected. If the playback devices are to be freshly loaded after an item, then the operation of selecting the cassettes can only be commenced after the preceding cassette has been filed.This determines the minimum time of each item if a plurality of short items follow in succession. Continuous operation is then possible when the sum of the times of three succeeding items is greater than 21 sec.

Therefore the construction using three playback devices will be the normally preferred one on account of the many advantages, and not least on account of the high degree of operational reliability.

The fact that the tape driving mechanism of a portable version of a B-format video cassette recorder can be employed in automatic multiple tape cassette systems is a notable advantage from the point of view of operation and supervision. In this case, because no account needs to be taken of the limitations in respect of power, space and weight of the relevant portable machine, it is possible to put into practice all the characteristics of a modern studio machine, such as slow motion, jogging, individual picture feed and high selection speeds.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a perspective view of an embodiment of an automatic multiple tape cassette system according to the invention, Figure 2 illustrates the mechanical section of the system of Fig. 1, Figure 3 is a more detailed view of part of Fig. 2, Figure 4 shows an intermittently operating self-locking gear associated with a playback device of the system for effecting timed intermittent movements of a driving shaft and a rising cassette table, Figure 5 shows the gear of Fig. 4 in perspective view, Figure 6 is a diagram of the cycle of movement of the gear of Fig. 4 when a cassette is being loaded onto a playback device, Figure 7 shows the cycle of movement of the gear of Fig. 4 when a cassette is being unloaded, Figure 8 is a block schematic electrical diagram of the system of Fig. 1, and Figure 9 is a timing diagram of the insertion and withdrawal operations using three tape playback devices.

In Fig. 1 there is shown an embodiment of the invention having a magazine for 32 video tape cassettes arranged in a planar matrix.

The cassettes are filed in 4 superposed rows of 8 adjacent columns. A gripper mechanism, which will be described later in more detail, withdraws from the rearwardly open side of the magazine the particular cassette intended for the next playback operation and delivers the cassette to a selected one of three playback devices. The playback devices are situated in the lower compartment of the magazine cupboard indicated by the reference 1, and are located in substantially the same plane as that of the cassette matrix. During the playback of the cassette taken from the magazine, the gripper mechanism is capable of delivering a second similar cassette to a rewinding device (which may be a playback device operating in a rewind mode) where, contemporaneously with the playback operation of the first mentioned cassette, the second cassette can be rewound to the start of the tape or reversed to a selected tape position. The apparatus at the right hand side of the switching cupboard has the function of supervising and monitoring the equipment and a block schematic diagram thereof will be described later.

In the mechanical section of the system shown in Fig. 2, a hoist carriage 5 carrying a trolley 6 is arranged to move upon two vertical columns 3, 4. The hoist carriage can be moved in a vertical direction by means of electric motors, and the trolley 6 is moved by means of a further electric motor horizontally upon suitable guide tracks of the hoist carriage 5. Advantageously the electric motors used for driving the mechanism are situated in stationary portions of the apparatus and drive the working parts through gear belts. In Fig. 2 there is also shown a belt transmission between a lower belt pulley 7 and a higher belt pulley 8, the latter serving to intermittently drive a driving shaft secured to it which cooperates with a respective playback device in a manner to be described later.Three pulley sets 7, 8 are provided, each associated with a respective playback device, although only one such set is shown. The playback devices are mounted behind the back plate on which the pulley 8 is mounted, the latter cooperating with the playback device through the apertures shown in Fig. 2.

In the more detailed view of Fig. 3 the trolley 6 is shown movably mounted by means of rollers 10, 11, 12 upon suitable guide rails 13, 14 of the hoist carriage. A gear belt 15 transmits to the trolley 6 the torque of a motor mounted in the hoist carriage and thereby effects the movement of the trolley in the horizontal direction. The trolley 6 carries at the bottom a telescopic tongs 20, the jaws 21, 22 of which can be opened and closed by means of a driving motor 23 and a leadscrew spindle having a left-hand and a right-hand thread. By means of an electric motor (not shown in the drawing) the telescopic tongs can be moved in the direction normal to the plane of the drawing and can thereby withdraw a cassette from the cassette magazine by holding it between the jaws 21, 22 and transfer it to a playback device, and carry out the operation in the reverse direction.The motors used for driving the hoist carriage, the trolley and the telescopic tongs are advantageously step motors, which when digitally controlled make possible accurate reproduction of the control instruction.

For the purpose of playing back the cassetted magnetic tapes, a playback mechanism may be employed of the kind described in U.K. Patent Application 7906149. The cassette table and tape threading motions of such playback device, described in the aforementioned application as derived from a main shaft, are operated in the present system by the driving shaft secured to the driving pulley 8. In Fig. 4 there is shown a plan view of the arrangment of the gear wheels of an intermittently operating and self-locking gear associated with the driving pulley 8. Fig. 5 shows the entire drive in a perspective view, whilst Figs. 6 and 7 illustrate the cooperation between the driving and driven wheels during the operations of loading and unloading the playback device respectively.It will be seen by inspection of the figures that the gear effects movement in close succession of the playback device main shaft and cassette table in the correct order for loading and unloading the playback device.

The invention is not, however, restricted to the use of playback devices of the kind disclosed in the aforementioned Patent Application, and the devices can be of any kind conventionally used in multiple cassette systems and which can receive a cassette from the gripper mechanism. In such case the gearing or mechanical coupling from the pulley 8 would be designed to effect movement of a received cassette into an operative position in the device and, if the tape threading is effected mechanically, subsequent threading of the tape. The pulley 8 would also carry out the reverse operations prior to removal of the cassette by the gripper mechanism.

Fig. 8 is an electrical block schematic diagram of the automatic tape cassette system wherein there are shown three playback devices 31, 32, 33. The playback devices are controlled by a computerised control unit 34.

To this control unit there is also connected the manipulator 35 (corresponding to the mechanism of Fig. 2) for transporting the cassettes to and from the playback devices. A keyboard is provided in combination with a display device 36, so that the necessary operating instructions or commands may be given for a desired television programme and the current operating condition of the system can be indicated.

For the purpose of reproducing a prescribed television programme consisting of a sequence of items, a suitable sequence of operations is keyed into the system by the keyboard 36, so that selected cassettes are successively transferred automatically to and from the magazine into vacant ones of the playback devices 31, 32 and 33, and the latter are automatically switched into playback operation at the appropriate times in accordance with the desired sequence of items which has been keyed into the system. The resulting video signals are amplified in respective reproduction amplifiers 37, 38, 39 and are delivered through an output selector switch 40 to a so-called video processor 41, which incorporates circuit arrangements for compensating time errors and for compensating signal discontinuities.From this video processor the signals can be delivered to an output terminal 42 of the arrangement.

Besides being used for the reproduction of prerecorded material according to a selected programme, the system can also be used for the recording of video signals. For this purpose the video signals to be recorded are introduced at 43 and are delivered through an input selector switch 44 to the individual playback devices, which then proceed to operate in the recording mode. The system also permits one to play back signals from one cassette and to record upon one or two other cassettes. For this purpose one of the playback stations is switched over to the reproduction mode, and the signal is delivered through the corresponding reproduction amplifier to the output selector switch. In the video processor the signal is corrected and eventually delivered to a further input 46 of the input selector switch 44.

As an extension of the operating possibilities the system includes a picture store 47.

This picture store 47 is designed as a digital store and can receive and store a complete television picture. The input of the picture store 47 is connected through a further output selector switch 45 to the output of the video processor 41 as well as to the outputs of the reproduction amplifiers 37, 38, 39.

The output of the picture store 47, as well as the output of the video processor 41, is connected to a selector switch device 48, whereby the signal from the video processor or the output signal of the picture store can be selectively delivered to the output terminal 42. All of the output signals of the various components of the system can be connected to a crossbar 49, the output of which is connected to a monitoring device 50.

With the picture store 47 the operational possibilities of the system are extended as follows: whilst the signals from the one cassette are being reproduced, for example by the playback device 31, and are being delivered through the video processor 41 and the selector device 48 to the output terminal 42, and therefrom, for example, to a broadcast transmitter, the next following cassette, for example, is inserted in the playback device 32. By means of a momentary switching operation at the playback device 32 and a subsequent rewinding of the cassette to the starting position, the first picture from the cassette in the playback device 32 is taken through the selector switch 45 and recorded in the picture store 47. By suitable switching of the crossbar 49, this picture is rendered visible by means of the monitoring device 50, so that during the time of transmission of the content of the cassette situated in the playback device 31, the first picture of the cassette which is next in the time sequence is rendered visible. Moreover it is also possible by the aid of the picture store, to play back a predetermined scene on one of the cassettes into another one of the cassettes via the selector switch 44, in such a manner that the latter can be used for a still picture for a predetermined period without further use of a picture store.

A time code generator 51 produces in known manner signals for recording upon one of the longitudinal tracks of the magnetic tapes, as is at present conventional practice in the technique of television magnetic tapes.

Claims (13)

1. Automatic playback and changing equipment for tape cassettes, characterized by the arrangement of the tape cassettes in a planar matrix.

2. An automatic multiple tape cassette system comprising a plurality of tape cassettes accommodated in a magazine, and means for the automatic transference of selected cassettes in the magazine to and from at least one tape playback device in a predetermined sequence, wherein the tape cassettes are arranged in a planar matrix in the magazine.

3. A system according to claim 2, in which the transference means comprises a gripper mechanism allowing selective access to any tape cassette in the matrix.

4. A system according to claim 3, wherein the gripper mechanism is movable in three planes mutually at right-angles to each other.

5. A system according to claim 4, wherein the gripper mechanism comprises a hoist carriage which is motor driven to move in a first (X) direction, a trolley mounted on the hoist carriage for motor driven movement in a second (Y) direction, and a gripper tongs mechanism mounted on the trolley for motor driven movement in a third (Z) direction, the gripper tongs being motor driven for opening and closing movement.

6. A system according to claim 2, 3, 4 or 5, wherein a plurality of playback devices are provided in substantially the same plane as that of the matrix.

7. A system according to claim 2, comprising an intermittently operating gear associated with the playback device arranged to effect movements in close succession of a main shaft and a lifting table for receiving a cassette intended for playback.

8. A system according to claim 7, wherein the main shaft is capable of being coupled to a playback device in accordance with U.K.

Patent Application 7906194.

9. Automatic playback and changing equipment for tape cassettes comprising a plurality of recording and playback devices, a plurality of inputs for signals to be recorded on the devices, the inputs being connected to the devices through an input selector, and a respective reproduction amplifier associated with each recording and playback device, the outputs of the amplifiers being connected through an output selector to a video processor comprising circuits for compensating time errors and for compensating signal discontinuities, and an output of the video processor being connected to an input of the input selector, a further output of the video processor being provided for reproduction signals.

10. Automatic playback and changing equipment according to claim 9, further comprising a further output selector connected to the amplifiers, and a picture store connected to the output of the further output selector, an output of the picture store being connected to an input of the input selector, and a further output of the picture store and an output of the video processor being selectively connectable to an output terminal of the equipment.

11. Automatic playback and changing equipment according to claim 10, further comprising a monitoring device selectively connectable through a crossbar to the outputs of the reproduction amplifiers, an output of the video processor, and an output of the picture store.

12. Automatic playback and changing equipment according to claim 9, wherein a computerised control unit controls the timing of the automatic operation of the system.

13. A system according to claim 2, substantially as described herein, with reference to the accompanying drawings.