Appeal No. 1996-3996
Application 08/250,578
including both a standard play mode (SP), and a long play mode (LP). In order to record and
reproduce to a magnetic tape that includes both SP and LP modes, the inventor sets out as
objectives, an LP mode that has favorable signal R/R characteristics, a track pitch that is
identical for both modes, an improved signal to noise ratio, an identical cylinder rotation speed,
and the ability to handle both recording and reproduction in LP mode. To meet these
objectives, the claimed invention has a reduced tape speed for LP mode to 1/N of SP mode,
data compression of the signal to be recorded, and recording only for every N rotations in LP
mode. N is an even number.
Beginning on page 24 of the specification, Appellant has disclosed an embodiment
where the factor N is two. Figure 4 illustrates the basic mechanism of the invention, where
rotary head cylinder 5 rotates at a cylinder rotation speed that is the same for both SP and LP
modes. The tape 8 runs at a constant tape speed for LP mode that is half that of SP mode.
Figure 9 illustrates the track pattern in LP mode, where each track A and B has a width of one
track pitch t, and recording or reproduction is done during a period corresponding to one
rotation of every 2 rotations of the rotary head cylinder. Figure 10 illustrates the formation of
record data blocks wherein the amount of information is reduced to half. Compression of the
signal by half allows recording within a track pitch t for LP mode. Appellant also describes that
the RF pulses in the LP mode are identical to the RF pulses in the SP mode.
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