GB2095213A - Cassette with tape usage meter - Google Patents

Abstract

A cassette or cartridge (30) containing a tape (33) capable of having information recorded thereon, the tape having signals, e.g. perforations, recorded along its length, preferably at regular intervals the cassette or cartridge further comprising means for detecting (38) and means for counting the signals (39) and means for displaying the count within the cassette and/or communicating the count to a separate reading device or playing machine. The arrangement is particularly suitable for video cassettes although is equally applicable to audio cinematographic and microfilm tapes, and may include means to disable the cassette after a pre-determined period of use. The signals received by the detecting means are lengthened within an electronic circuit so that their length is rendered just less than the length of the period between the pulses generated during the fastest possible playing speed, the counter thus recording a single continuous signal during the even faster fast-forward or rewind speeds. <IMAGE>

Description

SPECIFICATION Cassette tape usage meter This invention relates to cassettes or cartridges containing tape capable of having information recorded thereon and in particular to cassettes or cartridges including means for monitoring the tape usage.

Cassettes and cartridges are used in a number of fields, for example, audio recording, video recording, microfilm storage and cinematographic recording. There is a demand for monitoring the usage of the tape and the position of information recorded on the tape in many fields. For example, for information retrieval purposes, it is desirable to be able to quickly locate the position of particular stored information, and in the video cassette market where cassettes are hired or leased, it is desirable to monitor the usage of the tape in individual cassettes to allow a detection of the total running time throughout the life of a tape to indicate when replacement is due.

There are various methods of monitoring tape usage. German Auslegeschrift No. 2 047 667 discloses a tape cassette insertion counter and United States Patent Specification No. 2 477 146 discloses a tape magazine with an odometer-type counter. The latter device relies upon a mechanical device which is geared to the rotation of the spool in the cassette.

Magnetic recording tape has been provided with specific signals recorded onto the tape which are subsequently used for detecting the position of recorded information on a tape. Examples of such use include the video field in which specific signals are recorded onto the tape, for cueing or run detection, and in the computer field where such signals are used for data retrieval.

United States Patent Specification Nos.

2 364 556 and 2 477 146 disclose the use of a magnetic recording head alone within a cassette which is used for translation of the information recorded upon the magazine media. The magnetic recording head is not used for tape usage monitoring.

Rental of pre-recorded video cassettes in the consumer market is an expanding business.

Generally a fee is charged for a specific rental period but there is no way of knowing, controlling or charging for the number of times the tape is viewed within that period. Accordingly there is a demand for monitoring the usage of such tapes.

It is an object of the present invention to provide a cassette or cartridge which includes means for monitoring tape usage.

Therefore according to the present invention there is provided a cassette or cartridge containing a tape capable of having information recorded thereon, the tape having periodic signals, preferably regular signals, recorded along its length, the cassette or cartridge further comprising means for detecting and means for counting said periodic signals.

The invention provides a cassette or cartridge which has monitoring means integral therewith and accordingly it is possible to provide cassettes in which the extent of tape usage can be determined and means for data retrieval.

The invention is particularly useful in the rental of pre-recorded video cassettes. At the time a cassette is rented the value of the count may be logged and upon return the new value of the count is determined, the difference between the two values being an indication of the tape usage. Thus, it is possible to monitor, and if desired levy a charge for, the extent of tape usage. According to one aspect of the invention described hereinafter the cassette may be disabled after the tape has been used for a predetermined period.

In accordance with one embodiment of the invention, the cassette additionally comprises visual display means for displaying the number of signals counted. Suitable display means include liquid crystal displays, and light emitting diode displays. The preferred display is a liquid crystal display because of its adequate life time, small current consumption and small physical dimensions. The cassette may provide an output which is utilized by the recording/playing machine for providing an external display on the machine, in place of or in combination with the display on a cassette.Alternatively, the visually read display may be dispensed with, and means arranged so that the accummulated count may be communicated to a separate reading device, either by means of an electrical connector on the exterior of the cassette or cartridge, engagable by the reading device, or by means of a momentary illuminated light emitting display within the cassette or cartridge which transfers information to photosensitive cells which form part of the reading device.

The cassette preferably includes a magnetic recording tape, more preferably a video recording tape. Most formats of video tape have a frame synchronising or control track upon which near regular signal pulses are recorded, and where such signals are present upon the tape recording it is convenient to make use of them. In a perfect system these pulses would be recorded at exactly regular intervals, but in practical machines such precision is not achieved, and very minor differences occur, due for example to small changes in tape speed. These differences, however, do not significantly effect the described operation of the metering device. If such a conventional control track is not used, regular signals may be found within the video information track, or may be deliberately added to a prerecorded tape destined for hire by using part of the tape not used for information signals.

The magnetic tape cassettes in accordance with the invention are provided with a magnetic sensing head which contacts the tape and picks up the regular signals as the tape is passed by the sensing head. The cassette also includes the necessary electrical circuitry to amplify and rectify the signal picked up by the sensing head and to count the rectified signals and provide a display or a suitable output for the playing machine or reading device.

Most video recorders operate at variable tape speeds and it is desirable that the detection and counting means accommodate this. In many cases it may not be necessary or desirable to monitor the tape when it is moving at fast-forward or rewind speeds. Electrical circuitry for achieving this may be incorporated within the cassette and a convenient means of speed discrimination is to cause a lengthening of the duration of a detected synchronising pulse so that its length is rendered just less than the length of the period between pulses generated by the fastest viewing speed.

Thus, at speeds faster than viewing speeds, for example, rewind speed, the train of pulses would merge with one another to produce a single continuous pulse while that faster speed was maintained.

It is possible to identify particular zones within a length of tape by counting the detected synchronising pulses and thus one can gain access to a particular frame or passage of recorded information. Thus, the cassette of the invention may be used for retrieving stored data. This indexing may be performed entirely within the cassette and accordingly no modification of existing playback machines is necessary to provide these features.

A further use of the data obtained by counting the detected pulses is to compare the count detected with a predetermined value and upon reaching the predetermined value implement a certain function, for example, disablement of the cassette. This embodiment is of particular advantage in the hire or rental trade for video cassettes since it is possible to programme the cassette so that it is disabled after a certain predetermined period of tape play.Disablement may take the form of a mechanical lock within the cassette which is activated when the counted pulses reach a predetermined value or an electrical device which is used to simulate the end of tape detection system used within the replay machine. Forexample, in certain machines, the end of tape detection is optical and the lead-in of the tape is transparent, the stop mechanism being activated by a photoreceptor receiving light passed through the tape. In such a device, the disablement means may illuminate the photoreceptor which controls the stop mechanism is activated. This may be followed by a mechanical lock which is engaged within the cassette to prevent further use.

The invention is also applicable to other tapes such as cinematographic, microfilm and paper tapes, particularly those which are encoded by punching perforations. Cassettes of this type may include optical means, for example a photocell, which detect pulses of light as the tape is run. The regular signals may be produced by the individual frames of the cinematographic film or microfilm records, by the regular darkened areas or bands e.g. at one edge of the tape, or by perforations, e.g. sprocket holes for tape drive, in any of the tapes.

The invention will now be described with reference to the accompanying drawings, in which: Figure 1 represents a diagram of the format of a video tape, Figure 2 represents a block diagram of the detection system suitable for use with a cassette in accordance with the invention, Figure 3 represents a diagram of the format of the video cassette in accordance with the invention, Figure 4 represents a block diagram of a cassette in accordance with the invention and the possible output therefrom, Figure 5 represents a circuit diagram of a tape usage meter for a video cassette in accordance with the invention.

Figure 1 diagrammatically shows a video tape (1) which is divided into linear zones (tracks) across its width, which are allocated to various purposes. In the tape shown in Figure 1 there is a track 2 dedicated to sound information, track 3 dedicated to video information which comprises a series of regular traces and track 4 dedicated to picture synchronising pulses. The picture synchronising pulses 4 are spaced at regular intervals along the tape and may be used in the invention as a means of monitoring the tape usage. In certain formats additional tracks may be incorporated, e.g. for bidirectional play, or for other purposes Figure 2 is a block diagram showing the sensing means and associated circuitry to provide a display all of which may be included within a cassette.The electrical circuitry is designed to amplify and rectify the output from the sensing head and to lengthen the duration of the synchronising pulse so that at rewind speed only a single continuous pulse is detected. Suitable circuitry is available in the electronic industry and may readily be constructed to occupy small physical dimensions for incorporation within a cassette. The display is preferably a liquid crystal display.

The electronic circuitry includes means to count the pulses and to display the number of counts.

Optionally, the circuitry can include means to compare the count with a predetermined value stored within the electronic device, such that on reaching the predetermined value the cassette is disabled as described above. The circuitry may also be used to indicate the speed at which the tape is run by measuring the time elapsed between detected signals from the tape.

Figure 3 shows the general layout of a VHS type of video cassette which is currently available.

The cassette 30 has overall outside dimension of 1 8.8x 10.3 x2.5 cm. Within the cassette case are two spools 31, 32 which support the magnetic tape 33 (represented by a dashed line). The tape 33 follows a path from spool 31 to take-up spool 32 through guiding spindles 34. The portion 35 of the tape is engaged by the "lace-up" mechanism of the video recorder when the tape guard (not shown) is retracted as the cassette is inserted in the video recorder.

The cassette further comprises an aperture which accepts a lamphouse which is part of the optical system on the playing machine which detects the end of the tape in the cassette and switches off the tape drive. A spool locking device 37 is provided to immobilise the spool 31,32 when the cassette is removed from the playing machine.

The enclosed volume within the cassette is not fully occupied by the above described components and accordingly it is readily possible to incorporate a magnetic sensing head, display and associated electronic package together with batteries within the confines of the cassette. The exemplified layout shows a sensing head 38, display and electronic package 39 and batteries 40, all positioned within the cassette. One advantage of having the sensing circuitry entirely within the cassette is that the tape usage of individual cassettes is readily monitored. Furthermore, disablement means may be included within the cassette to disable the cassette after a predetermined period of use. A further advantage of including all the components within the cassette is that it is not readily possible for a hirer to tamper with the counting or disabling means.

Figure 4 is a block diagram of the various functions of a cassette in accordance with the invention. The cassette may be designed to display the number of pulses counted, which display may be used as an indication of time or run and of the length of tape used. Furthermore, the display count may be used as an index for identification of recorded material and for information retrieval. The count of pulses may also be used to trigger disabling means for the cassette after a predetermined count.

Figure 5 represents a schematic electrical fault diagram which exemplifies the main metering function of the device and is constructed using "off-the-shelf" components. For simplicity a light emitting diode is used and the count displayed iri binary form. The references 7611, 4020, 4040, 4027 and ULN 2003 refer to integrated circuits which are commercially available. The numbers within the integrated circuits denote the connection pins used. Q5 to Q1 1 are outputs from l.C. 4040 to ULN 2003 which drives the light emitting diode display.

The circuit illustrated has been assembled on a small printed circuit board and incorporated into a VHS cassette. However, it will be readily appreciated that the size of such a circuit is very large compared to the size of a minaturised assembly which could readily be made using known techniques.

Claims (15)

1. A cassette or cartridge containing a tape capable of having information recorded thereon, the tape having periodic signals recorded throughout its length characterised in that the cassette or cartridge further comprises means for detecting and means for counting said periodic signals.

2. A cassette or cartridge as claimed in Claim 1 in which said periodic signals are regular signals.

3. A cassette or cartridge as claimed in Claim 1 or Claim 2 characterised in that the cassette or cartridge additionally comprises visual display means for displaying the number of regular signals counted.

4. A cassette or cartridge as claimed in any one of claims 1 to 3 characterised in that the tape is a magnetic tape and the detecting means comprises a magnetic sensing head which contacts the tape at least when the cassette is in use.

5. A cassette or cartridge as claimed in Claim 4 which is a video cassette.

6. A cassette or cartridge as claimed in Claim 5, in which the regular signals comprise the frame synchronising pulse or are contained in the video signal tracks recorded on the tape.

7. A cassette or cartridge as claimed in any preceding claim characterised in that the counting means does not count each of said signals when the tape is at fast-forward and/or fast rewind speed.

8. A cassette or cartridge as claimed in Claim 7 characterised in that the signals received by the detecting means are lengthened within an electronic circuit so that the length is greater than the length of the period between pulses during fast rewind and/or fast forward speed whereby the counter records a single pulse during said fast speeds.

9. A cassette or cartridge as claimed in any preceding claim characterised in that the cassette includes means to communicate the count to a separate reading device or playing machine.

10. A cassette or cartridge as claimed in any preceding claim characterised in that it additionally comprises means to prevent tape movement when the counts recorded have reached a pre-determined value.

11. A cassette or cartridge as claimed in any one of claims 1 to 3 characterised in that the tape is transparent having recorded information thereon and the detecting means is optical.

12. A cassette or cartridge as claimed in Claim 11 characterised in that the regular signals comprise frames of information recorded on the tape.

13. A cassette or cartridge as claimed in Claim 11 characterised in that the tape is a cineomatographicfilm or film bearing microfilm records.

14. A cassette as claimed in any one of Claims 1 to 3 characterised in that the tape is a paper tape having regular signals recorded thereon in the form of perforations and the detecting means is optical.

15. A cassette or cartridge as claimed in Claim 1 substantially as herein described with reference to any one of the Examples.