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Federal Circuit Reversed Improperly Narrowing Claim Construction

September 09, 2011
Tull, Susan Y.

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Last Month at the Federal Circuit - October 2011

Judges: Newman (dissenting), Clevenger, Linn (per curium)

[Appealed from: D.N.H., Judge Barbadoro]

In Markem-Imaje Corp. v. Zipher Ltd., No. 10-1305 (Fed. Cir. Sept. 9, 2011), the Federal Circuit held that the district court erred in construing a critical claim term, vacating the court’s SJ of noninfringement and remanding for further proceedings under the corrected construction.

Markem-Imaje Corp. (“Markem”) sued Zipher Ltd. and Videojet Technologies, Inc. (collectively “Zipher”) for a DJ that Markem did not infringe Zipher’s U.S. Patent No. 7,150,572 (“the ’572 patent”). The ’572 patent describes a device for transfer printing, where ink is transferred to a material substrate by moving a ribbon with ink into contact with the substrate, and then impressing upon the ribbon with a print head, causing the ink to transfer to the substrate. In transfer printers, the ink ribbon is generally wound on two spools: one spool supplies and positions the ribbon; the other spool takes up the ribbon after printing. The ribbon must be kept at a certain tension to prevent breakage from too much tension or slackening from too little tension.

The ’572 patent “is directed to an improvement in controlling the movement and tension of the ribbon.” Slip op. at 3-4. Prior art printing devices typically drive only the take-up spool, applying a constant resistant torque to the supply spool. The printing device of the ’572 patent, however, drives both the
take-up spool and the supply spool using stepper motors, which, when still, apply a holding torque to keep the ribbon in place.

Claim 1 of the ’572 patent describes a tape drive comprising two motors, at least one of which is a stepper motor, on which tape spools are mounted. The spools are each “drivable” by one of the motors. The tape drive of claim 1 also includes a controller that “energizes both said motors to drive the spools in a tape transport direction, and said controller calculates a length of tape to be added to or subtracted from tape extending between said spools in order to maintain tension in said tape between predetermined limit values and controls said motors to drive the spools to add or subtract the calculated length of tape . . . .” Id. at 8 (emphases added).

The district court construed the term “drive” and “drivable” in the ’572 patent to mean “rotate” and “rotatable.” It was undisputed that Markem’s accused devices rotated both spools during the tape tension adjustment process, but only rotated a single spool to each adjustment. If tape tension was too high, the supply spool was rotated, and if tape tension was too low, only the take-up spool was rotated. Given its construction of “drive,” which required that both spools rotate together to adjust the tape, the district court granted SJ of noninfringement.

On appeal, Zipher argued that the district court erred in limiting the meaning of “drive” to “rotate,” and urged the construction “hold steady in a commanded position” instead. The district court had acknowledged that the ordinary meaning of “drive” was broad enough to encompass rotation of the spools as well as the application of a holding torque that prevented rotation, but found that other usages in the specification supported the narrower construction. The Federal Circuit disagreed, finding that
“[n]othing in the specification or the overall invention as presented in the claim and as argued to the patent examiner [during prosecution] requires the narrow construction.” Id. at 12. But rather, as the Court noted, motor functions in the specification included “rotating, holding steady, stopping, accelerating, decelerating, and all the other drive functions the motors perform.” Id. at 12-13 (citation omitted). Accordingly, the Court found that the specification did not support the district court’s construction.

Turning next to the prosecution history, the Federal Circuit considered the examiner amendment in which “controls said motors to add or subtract the calculated length of tape” was changed to “controls said motors to drive the spools to add or subtract the calculated length of tape” in order to “more clearly define the scope of claim [1].” Id. at 14. The Court could “discern no indication that the added phrase ‘to drive the spools’ in the examiner’s amendment was intended or understood to limit ‘drive’ to ‘rotate,’ for that was not an issue of examination.” Id. Indeed, “[t]he examiner’s amendment accord[ed] with the ’572 patent’s requirement that the motors apply torque to the spools, whether the torque cause[d] the rotation or resist[ed] it.” Id. The Court thus held that the term “drive” was properly construed to mean “the application of torque to the spools, whether the torque causes rotation or resists it” (id. at 16), vacating the judgment of noninfringement and remanding for determination under the correct construction.

In addition, Zipher challenged the district court’s construction that the claims require “some method of deriving a tension measurement.” Id. at 15. Zipher argued that the district court’s construction improperly imported a limitation into the specification, where the claim did not explicitly recite measuring tension. The Federal Circuit agreed. “That a device will only operate if certain elements are included is not grounds to incorporate those elements into the construction of the claims.” Id. Accordingly, the Court reversed the district court’s determination that the claims require “some method of deriving a tension measurement.” Id. at 16.

In her dissent, Judge Newman concurred with the Court’s holding with respect to the term “drive” but disagreed with respect to the phrase “some method of deriving a tension measurement.” Judge Newman concluded that some method of tension measurement was indeed necessary to carry out the invention, and that the majority’s opinion “ignore[d] the paramount importance of the specification in claim construction.” Newman Dissent at 1. “Where the specification clearly and consistently sets the scope of a disputed claim, that scope governs the construction of the claim.” Id. at 2. Agreeing with the district court’s construction, Judge Newman concluded that some method of measurement was contemplated and required by the specification.

Summary authored by Susan Y. Tull, Esq.