Appeal No. 95-3876
Application 08/222,009
grounded and the insulated gate bipolar transistor IGBT is
therefore switched off." The specification also describes
that the IGBT is switched off when transistors Q3 and Q6 are
turned on (and, hence, transistors Q4 and Q5 are turned off)
(specification, page 30, lines 10-13): "Subsequently, when an
exposure gets proper, the transistors Q3 and Q5 [sic, Q6] are
switched on and the insulated gate bipolar transistor IGBT is
switched off to terminate the flash firing." In my opinion,
it is apparent from Iwata that appellants' transistors Q4 and
Q5 can alone perform the function of "removing the enabling
voltage," which is broadly defined as turning off the voltage
to the gate of the IGBT. In summary, the function of
"removing the enabling voltage" is performed by:
(1) switching on transistor Q3; or (2) switching off
transistors Q4 and Q5; or (3) both switching on transistor Q3
and switching off transistors Q4 and Q5. I would construe the
"control means . . . for removing the enabling voltage at the
gate" to correspond any of these structures. Since
appellants' transistors Q4 and Q5 are identical to transistors
22 and 23 in Iwata, the claimed "control means . . . for
removing the enabling voltage at the gate" does not define
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