Appeal No. 1998-0153
Application No. 08/497,227
BACKGROUND
The appellant's invention relates to a buzzer driving device using a hysteresis circuit
to compensate for fluctuations in signal levels. An understanding of the invention can be
derived from a reading of exemplary claim 1, which is reproduced below.
1. A device connectable with a direct current source (1) for
driving a buzzer (15), comprising:
switch means (2) for coupling said direct current source (1) to said
buzzer (15);
a charging /discharging circuit (3) connected with the direct-current
source (1) via said switch means (2) and which performs charging and
discharging at a predetermined time constant (CR) when the switch means
(2) is turned on and off, respectively, and produces an output voltage in
accordance therewith;
a hysteresis circuit (25) to which said output voltage of the
charging/discharging circuit (3) is input and which operates while the output
voltage rises to or above an operation threshold value (V ) after the start of
T
the charging of the charging/discharging circuit (3) and thereafter becomes
inoperative and remains inoperative unless the output voltage falls to or
below a stop threshold value (V ) which is smaller than the operation
S
threshold value (V ) due to the discharging of the charging/discharging circuit
T
(3); and
driving circuit (14), connected between said hysteresis circuit (25)
and said buzzer (15) for outputting a drive signal for said buzzer (15) in
response to the operation of the hysteresis circuit (25).
The prior art references of record relied upon by the examiner in rejecting the
appealed claims are:
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