Appeal No. 95-4788
Application 07/996,393
sweeping and for transferring and that reducing the amplitude of the vertical transfer clock pulses
will sufficiently sweep the residual charges. The admitted prior art discloses that conventional
imaging devices generate a great amount of power and heat in sweeping and transferring which
have an adverse effect on the characteristics of the sensor (specification, para. bridging pages 5-6).
Therefore, we agree with the examiner's finding that "[i]t is well known in the art of solid state
imaging that for sweep and transfer clock pulses generated during the vertical blanking period, the
power dissipation caused by the high repetition rates that are required can cause the generation
of undesirable heat contributing to an increase in unwanted charges due to thermal noise"
(Examiner's Answer, page 5). However, the admitted prior art does not suggest reducing the
voltage level used in sweeping to lower the overall power, and therefore the heat and undesired
characteristics, as a solution to the problem.
The admitted prior art in figure 4 discloses a driver 22 whose amplification factor is
controlled by a reference voltage from power circuit 26 (specification, page 4, lines 10-23). The
examiner's finding that "[i]t is also standard practice in the design of solid state imagers, as seen
in the admitted prior art device, to provide a means for varying the amplitude of clock pulse
voltages" (Examiner's Answer, page 5) is correct to the extent that the structure in figure 4
determines the amplitude in accordance with a reference voltage. However, the admitted prior
art does not suggest that the reference voltage is varied or that it takes on other than a single
value. While the admitted prior art driver may be capable of being modified to provide two
different amplifications the way appellant's apparatus is claimed, there must be a suggestion or
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Last modified: November 3, 2007