TAPE RECORDER CASSETTES PULSE MODULATED FOURIER TRANSFORM MAGNETIC RESONANCE SPECTRO METER UTILIZING QUADRATURE PHASE DETECTION AND HIGH PASS FILTER TO ELIMINATE UNDESIRED STRONG RESONANCE LINES

摘要

1448375 Counters ACTION DESIGN Ltd 7 Nov 1974 [8 Nov 1973] 51950/73 Heading G4D [Also in Division B8] A tape recorder cassette I has a counter 7 located in one corner provided with a spring biased pivoted arm 2 for bearing upon tape 4 to count the number of times the tape is played, the counter being such that it counts as a result of movement of the arm in one direction but is unchanged by movement of the arm in the opposite direction. In the embodiment of Fig. 1 the tape contacting end 2SP1/SP of the arm is smoothly curved. The other end 211 is arcuate and toothed, the teeth meshing with those of gear wheel 5 mounted on axle 6 of counter 7. The arm is spring biased towards the hub surface of spool 3 or to a position away from the surface. The spring (not shown) may act on axle 6 or directly on arm 2. Just before tape 4 is fully wound on to spool 8 the counter registers a single count. The counter is read through window 9. In the embodiment of Fig. 4 (not shown) the unwinding of the tape is counted. Arm (2a) swings inwardly as the tape unwinds until it strikes a stop 10 positioned such that the counter reads an exact integral count. A spring (11) biases the arm towards spool 8a.