Appeal No. 1999-1123
Application No. 08/576,915
identical control apparatus, as suggested by Kapes, Jr.
(column 3, lines 35-39).”
Dahlquist discloses control circuits 22-1 through 22-P
for supplying print voltages to styli 23-1 through 23-P,
respectively (Figure 2; column 6, lines 29 through 31). Each
of the control circuits includes two MOS transistors 49a and
49b that are connected together in series as a voltage divider
that applies voltage to the stylus connected thereto (Figure
4A; column 7, lines 52 through 61). The drain of transistor
49a is connected to D/A converter 45, and the source of this
transistor is connected to the drain of transistor 49b. The
source of transistor 49b is connected to a bias voltage V. A
programmable one-shot multivibrator 46 is connected to the
gate of transistor 49b, and to the gate of transistor 49a via
level converter 48 (column 7, lines 61 through 64). When the
one-shot multivibrator is triggered, the voltage supplied to
transistor 49a is sufficient to allow it to conduct and to
thereby cause the voltage on stylus 23-p to rise to
approximately the level of the output voltage from D/A
converter 45 (column 7, line 61 through column 8, line 1).
During this time, transistor 49b is turned off “so as to
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