Appeal No. 2003-2156
Application No. 09/849,761
appeal, irrespective of whether the unmuting and muting
functions are recited per se. This analog receiver muting
function was apparently only applicable to one band of
frequencies, and there was no signal summing operation.
The teachings of this just-discussed prior art was
applied to digital-to-analog converters according to the
discussion at pages 3 and 4 of the specification as filed in
a second example of what prior art squelching techniques
were utilized to function in a muting and unmuting
situation. This discussion makes reference to prior art
Figures 1 and 2. When the digital input signals to these
DACs were all zeros for a given time, the prior art
mute/unmute control muted the output signal. On the other
hand, any time the input signal was not zero, the output
signal was immediately unmuted. Again, these functions
relate to the corresponding functions of the claims on
appeal, yet still apparently applied to only one band of
frequencies and no signal summing operation. The top of
page 4 indicated that this approach was used in prior art CD
players.
5
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007