GB2177679A - Tape-loading apparatus for cassettes - Google Patents

Abstract

A tape-loading apparatus includes a supply spool 1 of magnetic tape 2, one track of which has a cue-tone signal recorded thereon at predetermined intervals to define pre-set lengths intermediate each signal for cutting and loading into respective cassettes. A full-track monitoring head 3 detects each cue-tone signal and a tape cutter 4 cuts the tape after a set time lapse. A half-track monitoring head 6 is positioned between the monitoring head 3 and the cutter 4, and the cutter is de-activated if the monitoring head 6 fails to detect the cue-tone signal or detects at least a substantial attenuation of the signal, thereby indicating that the tape 2 is twisted or otherwise misaligned. <IMAGE>

Description

SPECIFICATION Tape-loading apparatus for cassettes This invention relates to ta pe-loa di ng apparatus for cassettes.

Known apparatus of this type includes a supply spool of magnetic tape having a cue-tone signal recorded on one track of the tape at intervals defining predetermined lengths of blank or pre-recorded tape for loading into respective cassettes. The apparatus also includes a full-track monitoring head for detecting the cue-tone signal, which is used to activate a cutterfor cutting the tape into these required lengths.

However, problems may arise when the tape, fed from the supply spool, becomes twisted, either be fore orafter passing overthe monitoring head,there by preventing correct loading ofthe tape into the cassette for replay. Even if the tape becomes twisted before passing over the head, such twisting generally remains undetected bythe head and usually no provision is made downstream ofthe monitoring head to detect any twisting after the tape has passed the head.

Furthermore, such known apparatus is not always sufficiently reliable to ensure that the tape is cut at precisely the correct point.

It is therefore an object ofthe present invention to provide apparatus of the above-mentioned type, which is capable ofdetectingtwisting ofthetape prior to it being loaded into the cassette.

It is another object ofthe present invention to provide a more reliable apparatus ofthe abovementioned type than those known hitherto.

According to the present invention there is provided tape-loading apparatus for cassettes, said apparatus comprising a spool for retaining magnetic tape for loading into said cassettes, full-track monitoring means for detecting a cue-tone signal recorded on a track of said tape at intervals defining predetermined lengths of said tape, means for cutting said tape in response to said detected signal, half-track monitoring means, positioned between said full-track monitoring means and said cutting means, for monitoring said track, and means for de-activating said cutting means, if said half-track monitoring means fails to detect said cue-tone signal ordetects at least a substantial attenuation of said signal.

The invention will now befurtherdescribed by way of example only with reference to the accompanying drawings, wherein Figure 1 shows schematically the tape-loading apparatus, in accordance with the present invention, Figure 2 shows a block diagram of a circu it for controlling said apparatus and Figure3showsa more detailed circuitdiagram of that shown in Figure 2.

In Figure 1, a tape-loading apparatus includes a supplyspool 1,which retains magnetictape 2, one track ofwhich has a cue-tone signal recorded thereon at predetermined intervals along the length ofthe tape, to define pre-set lengths intermediate each cue toneforcutting and loading into respective cassettes.

These pre-set lengths ofthetape may be eitherblank or pre-recorded.

The tape 2 is fed to a full-track monitoring head 3, which monitors all tracks on the tape, including the one upon which the cue-tone is recorded, sothatthe head 3 detects each cue-tone as the tape 2 passes.

Once the cue-tone has been detected bythe head 3, a signal is passed to a tape cutter 4, which is arranged to cut the tape 2, after a set time lapse during which thetape 2 is constrained to follow a path comprising tape guide means, tape tension and speed monitor ing means, etc., as shown generally at 5.

The apparatus also includes a spool 6, which retains leadertape 7 to be spliced onto the ends ofthe cut lengths of tape 2. These cut lengths of the tape 2 are then each loaded into a cassette (not shown).

Problems arise with this apparatus, however, when the tape 2 becomes twisted along its path from the supply spool 1 to the cutter 4. Such twisting tends to remain undetected by the monitoring head 3, which monitors all the tracks on the tape 2, so that, irrespective of the tape orientation, the head 3 still detects the cue-tone. This then allows the twisted tape to be loaded into the cassettes, which prevents correct operation thereof.

To alleviate this problem, the present invention provides a second monitoring head 6, positioned between the monitoring head 3 and the cutter 4, and preferably closely adjacent the cutter. The monitoring head 6 is a half-track head and is positioned to monitor only the track of the tape 2, upon which the cuetone is recorded, when the tape is correctlyorientated. If, therefore the tape 2 becomes twisted or otherwise misaligned, the monitoring head 6 will not detectthe cue-tone or at least any cue-tone which it does detect will be considerably attenuated.If this condition is detected by the head 6,theapparatus, including the cutter 4, is immediately de-activated, and preferably a warning light (not shown) is illumin atedtowarna useroftheapparatusthatafaulthas occurred.

It can be envisaged that, not only is the half-track head 6 capable of detecting twisting of the tape, but it can also be used as a check forthe first head 3, both to ensure that the cue-tone is actually present and to determine exactly when the tape should be cut, thereby enabling the lengths ofthetape 2to be cut more precisely.

A circuit arrangement for putting the present inven- tion into effect is shown in Figures 2 and 3.

Referring now to these Figures, a signal 8 is generated bythefull-track head 3, when a cue-tone is detected on the tape 2, and this signal 8 is passed to an opto-isolator 9, wherein a LED 10 is activated and causes photo-transistor 11 to conduct, which triggers a timer 12.

If, when the cue-tone passes the half-track head 6, the tape 2 has not become twisted or misaligned, the head 6 generates a signal 13, which is passed to a pre-amplifier and filter circuit 14, which amplifies and filters the signal by a dual operational amplifier 15.

The filter has a bandwidth of 350Hz to 5KHz at the -3dB point, and the cue-tone has a typical frequency of 1 to 2 KHzfor a tape-winding speed of approximately 14 m/s.

The output of the pre-amplifier and filter circuit 14 is passed to a precision rectifier circuit 16, wherein the signal is rectified and integrated, via IC 17,zener diode 18 and diode 19. A LED 20 is illuminated, via a transistor2l,forthe duration ofthe signal, so asto assista userin setting uptheapparatusforcutting, cassette-loading, etc. The rectified signal is passed to a voltagefollowercircuit 22, wherein It 23 is used to supplyaSchmitttrigger24withcorrectworkingvol- tage pulses.

If, therefore, the half-track head 6 detects a normal cue-tone signal, Schmitt trigger 24 transmits a pulse to re-setthe timer 12 and the cutting process ofthe tape 2 is allowed to proceed.

If, however,thetape 2 has become twisted or misaligned, the half-track head 6 fails to detect a cue-tone signal or detects one which has been attenuated to below a predetermined level, in which case the Schmitttrigger 24 does not transmit a re-set signal to the timer 12.

A signal 25 is then generated, to activate the cutter 4, which illuminates a LED 26 in the opto-isolator9 and thus causes photo-transistor 27to conduct.

With the timer 12 not re-set, outputs from the timer 12 and the opto-isolator 9 pass through a logic unit 28 to trigger a transistor 31 into conduction causing a relay 30 to be energised,which de-activatesthe apparatus and thus prevents the cutting process from taking place. Also a second timer 29 energises a user error indicator (not shown), preferably for 30 secs., to warn a user of the apparatus that a fault has occurred.

Theindicatormaytaketheformofa LED or an audible alarm. The apparatus is preferably only de-activated momentarilyto enable a userto correctthe detected twisting ofthe tape before the tape is cut.

Claims (5)

1. Tape-loading apparatus for cassettes, said apparatus comprising a spool for retaining magnetic tape for loading into said cassettes, full-track monitoring meansfordetecting a cue-tone signal recorded on a track of said tape, means for cutting said tape in response to said detected signal, half-track monitoring means, positioned between said full-track monitoring means and said cutting means, for monitoring said track, and means for de-activating said cutting means if said half-track monitoring meansfailsto detect said cue-tone signal or detects at least a substantial attenuation of said signal.

2. Tape-loading apparatus as claimed in claim 1 and including means for indicating to a user of the apparatus when said half-track monitoring means has failed to detect said cue-tone signal or has detected at least a substantial attenuation of said signal.

3. Tape-loading apparatus as claimed in claim 1 or 2 wherein, following de-activation, said cutting means is arranged to be re-activated after a predetermined length oftime.

4. Tape-loading apparatus as claimed in any preceding claim and including means for indicating to a user of the apparatus when said half-track monitoring means has detected a cue-tone signal.

5. Tape-loading apparatus substantially as herein described with reference to the accompanying drawings.