Opinion ID: 2810823
Heading Depth: 2
Heading Rank: 3

Heading: “whenever defective”

Text: We turn to the construction of “whenever at least one discharge lamp is removed from the output terminals or is defective.” The “direct current blocking means” recited in claim 1 is “operable to stop flow of the control signal from the DC input terminals, whenever at least one gas dis- 18 LIGHTING BALLAST CONTROL LLC v. PHILIPS ELECTRONICS NORTH AMERICA charge lamp . . . is defective.” 3 The district court construed “defective” to mean “whenever the direct current path between [two terminals] is broken.” A51. The court relied on the following language in the specification for support: “the [direct current blocking means] will be held discharged for any period of time as long as: (i) there is an unbroken direct current path DCP between terminal B+ and terminal CTa . . . .” The district court’s construction is supported by the intrinsic record. The DC blocking means does not block control signal when a lamp is inserted into its holders and has a working filament. There is no need to block current in this instance because the circuit is closed, and there is no danger that current will dissipate into the ballast circuitry. As the district court recognized, on the other hand, the DC blocking means blocks control signal when a lamp is removed or when the lamp has a broken filament, i.e., when the direct current path between the relevant terminals (terminals B+ and CTa) is broken. As a result, the district court’s claim construction was not erroneous.