Appeal No. 1998-2513
Application No. 08/171,427
to “addition amplifier” 1. An independent speed control signal is produced by means of
circuitry at elements 4, 5, and 6, with the output being directed to “addition amplifier” 1.
The output of “addition amplifier” 1 is supplied to motor driver 2, which drives capstan
motor 3.
Takeda teaches that the “reference voltage generation circuit” 7b is an
improvement over simple reference voltage 7 (Figure 3), which sets the reference for
rotational frequency. See Takeda, page 7, second paragraph of the English translation.
Although in voltage form, the rotational frequency reference is analogous to the capstan
speed instruction “(f)” which is input to speed error detector 21 in appellant’s prior art
Figure 3, as described in the instant specification.
[T]he capstan speed instruction (f), which corresponds to the regular
spinning speed of the capstan motor and which is needed when [the] head
correctly runs [above the] normal track, is the reference value. Also, the
reference value and the actual speed of a capstan motor 27, as measured
by a frequency generator 29 when capstan motor 27 spins, are compared in
a capstan speed error detector 21.
Specification (Paper No. 1), page 3, lines 14-20.
According to appellant’s assessment of Takeda, “tracking and speed control are
supplied independently via an adder 1 to capstan motor 3.” (Brief, page 8.) “Therefore,
Takeda suffers from the same deficiencies of the conventional methods....” (Id.)
The examiner explains, on page 6 of the Answer, that the claimed subject matter
was suggested because the combination of the APA and Takeda would not produce
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