GB1429134A - Tape transport apparatus - Google Patents

Abstract

1429134 Tape transport apparatus NORDDEUTSCHE MENDE RUNDFUNK KG 4 April 1974 [4 Aug 1973 (2)] 14964/74 Heading G2E [Also in Divisions G4-G6] In apparatus for feeding a record-carrying tape such as a film strip 3 from a delivery spool 2 to a storage spool 12, the tape is scanned to produce a signal dependent on the speed of the tape, and if the signal is not present the tape is rewound on to the spool 2. Thus if the tape has left the guiding channel, or not been properly accepted by the storage spool, the re-winding means is activated. When the apparatus is initially switched on, a slide 38 is driven by motor 33 in the direction of arrow 50. A belt 41 passing round pulleys 39, 40 is carried forward into engagement with the tape on spool 2 and hence drives the spool clockwise. A stripper finger 52 engages the leading end 53 of the tape and guides it into a track 4. This carries it past the scanning means 6, and a further scanning means 5 for reproducing the images on the film strip on a television screen. It is now picked up by a capstan drive and guided to the storage spool 12. This has a number of curved blades 69, between which are suction intake orifices 70, Fig. 4 (not shown). As spool 12 is driven clockwise, a current of air is generated which helps to carry the leading edge of the film into entrainment with the hub and flanges of spool 12, and hence winds on to it. As the perforations 10 in the film strip pass the light source 7, a series of pulses is produced by the photo-cell 8, which are passed to a logic circuit 20. The motor 13, which drives spool 12, has a series of black and white markings 17, on which is directed light from a source 15. The reflected light is received by a photo-sensitive element 16, the resultant pulses also being passed to the logic circuit 20. If, after movement of strip 3 past the scanning means 6 has been initiated, no pulses are received by logic circuit 20 after a given delay period, indicating a transport defect, a motor 26 is energized, which brings a friction roller 27 into contact with spool 2 and rewinds on to it any strip which has been fed from it. If the strip has been correctly accepted by spool 12 and is winding on to it, this exercises a braking effect on the spool, which alters the frequency of the output pulses 23 from element 16. The logic circuit compares these pulses with those from element 8, and if they correspond approximately, indicating that the strip is being properly wound on to spool 12, this is allowed to continue. If the frequency 23 is still that of the unbraked spool, the rewind motor 26 is again energized to rewind the strip back on to spool 2. When the strip has come to an end, no more pulses appear from element 8, so that motor 26 is once more energized to rewind the strip. This can also be effected before the strip has come to an end, by actuating a control panel 29 to simulate the absence of pulses from element 8.