Jury's finding under doctrine of equivalents reversed
Energy Transportation Group, Inc. v. Sonic Innovations, Inc., et al., C.A. No. 05-422-GMS, June 7, 2011.
Sleet, C. J. Defendants’ motion for judgment as a matter of law of noninfringement and invalidity and for a new trial granted in part and denied in part. The jury’s finding of infringement under the doctrine of equivalents was reversed as to two claims of one of the patents-in-suit due to prosecution history estoppel. The jury’s finding of validity and infringement as to the other patent-in-suit was preserved. The defendants’ request for a new trial on the issues of infringement and invalidity was denied. Plaintiff’s motion for pre-judgment and post-judgment interest was granted. All other post-trial motions were denied.
This is a patent infringement case involving programmable digital hearing aids. On February 4, 2008, the jury returned a verdict for plaintiff following nine days of trial. Judgment was entered on February 8, 2008; and the parties filed their respective post-trial motions shortly thereafter. Substantial evidence existed in the record to support the jury’s finding that plaintiff’s patents were not invalid and that the defendants infringed all asserted claims of U.S. Patent No. 4,731,850 under the doctrine of equivalents and claim 19 of the’850 patent literally. The defendants did not infringe any asserted claim of U.S. Patent No. 4,879,749 under the doctrine of equivalents because of prosecution history estoppel. Plaintiff’s prosecution amendments surrendered claim scope that precluded operation of the doctrine of equivalents; thus the jury’s verdict that claims 1 and 2 of the ‘749 patent are infringed under the doctrine of equivalents cannot stand. Defendants were required to pay prejudgment interest on the final damages award at the prime rate calculated by spreading out the damages over the twenty-one quarterly royalty payments defendants would have made to plaintiff throughout the period in which defendants would have licensed the patents-in-suit and compounding the interest in each of the royalty payments on a quarterly basis and post-judgment interest on the final damages award pursuant to 28 U.S.C. § 1961. The remaining post-trial motions, including motions for a new trial, enhanced damages, and a finding of no willful infringement, were denied.
