## Facts

- Delta-X Corporation owned U.S. Patent No. 4,286,925 covering a control circuit that shuts off electric power to an oil-well pump when “fluid pound” occurs, a condition that can damage the pump rod.
- Delta-X sued Baker Hughes Production Tools, Inc. and Baker CAC for infringement of claims 1 and 2, including infringement under the doctrine of equivalents, based on Baker’s rod pump controllers.
- The parties disputed the meaning of “electrical comparator” in claim 1; Baker sought an instruction that the term was not synonymous with a computer.
- The district court declined Baker’s requested instruction and, in parts of the charge, placed responsibility on the jury to interpret the claims and compare them to the accused devices.
- A jury found infringement under the doctrine of equivalents and found willful infringement.
- Post-trial, the district court granted Baker judgment notwithstanding the verdict (JNOV) on willfulness and denied Delta-X’s requests for enhanced damages, attorneys’ fees, and costs.
- Delta-X appealed the JNOV on willfulness and the denial of enhanced relief; Baker cross-appealed, arguing prejudicial instructional error on infringement and claim interpretation.

## Issues

1. Whether the district court could grant JNOV on willfulness when Baker failed to move for a directed verdict at the close of evidence.
2. Whether any procedural error in granting JNOV was harmless because the district court independently denied enhanced damages, attorneys’ fees, and costs.
3. Whether the jury instructions on claim interpretation and infringement (including treatment of “electrical comparator” and doctrine of equivalents) contained prejudicial error requiring reversal or a new trial.

## Decision

- The district court erred in granting JNOV on willfulness because Baker had not made the required directed-verdict motion during trial.
- The JNOV error was harmless because the district court independently determined Delta-X was not entitled to enhanced damages, attorneys’ fees, or costs.
- The Federal Circuit found no prejudicial error in the jury instructions when viewed as a whole.
- The Federal Circuit affirmed the district court’s judgment in full, leaving the infringement judgment intact and the denial of enhanced monetary relief undisturbed.

## Legal Principles

- A post-verdict motion for JNOV (now JMOL under Rule 50(b)) must be preceded by a directed-verdict motion (Rule 50(a)); absent that prerequisite, granting JNOV is procedural error.
- An improper JNOV ruling may be harmless if the district court independently exercises its discretion on remedies (such as enhanced damages and fees) and that independent determination supports the same outcome.
- Enhanced damages under 35 U.S.C. § 284 and attorneys’ fees under 35 U.S.C. § 285 require a discretionary, case-specific determination; denial may be sustained even if a willfulness finding is set aside.
- Alleged instructional error is reviewed for prejudice in the context of the instructions as a whole; ambiguous or imperfect phrasing does not justify reversal absent a showing of prejudicial confusion affecting the verdict.

## Conclusion

The Federal Circuit held that JNOV on willfulness was procedurally improper without a directed-verdict motion, but affirmed because the error did not affect the outcome: the district court independently denied enhanced damages, fees, and costs, and the infringement verdict stood in the absence of prejudicial instructional error.


Delta-X Corp. v. Baker Hughes Prod. Tools, Inc., 984 F.2d 410 (Fed. Cir. 1993)