Beckman Coulter, Inc. v. Sysmex Am., Inc., No. 18 C 6563, Slip Op. (N.D. Ill. Apr. 26, 2019) (Rowland, Mag. J.).

Magistrate Judge Rowland granted in part defendants’ (collectively “Sysmex”) motion to compel more definite responses regarding plaintiff Beckman Coulter’s dates of conception and reduction to practice in this patent case involving automated software for testing specimens.

The Court held that Beckman Coulter had the burden of establishing its conception and reduction to practice and dates of conception and reduction to practice were material to Sysmex’s invalidity defenses. The Court held that Sysmex had to provide “actual or approximate specific dates.” Date ranges were insufficient and Beckman Coulter’s identification of “spring of 1997” was worse than a range in that it was an “ill-defined range.” An estimate of dates was allowed where the party could not identify a precise date in good faith, but not a range of dates and particularly not a six month range, such as spring.

The Court also noted that the Local Patent Rules had a “shifting sands” approach to claim construction which required each sides to set out clear positions by their respective deadlines. The Court noted that Sysmex would be limited in its number of prior art references pursuant to LPR 3.1 and that it would not be allowed to amend its final contentions absent leave of Court for good cause and without prejudice, pursuant to LPR 3.4. Additionally, the Court noted that fact discovery closed before claim construction and, while it may reopen after claim construction, that is only if a party seeks reopening fact discovery pursuant to LPR 1.3 and provides a valid reason for doing so. As such, Beckman Coulter was required to respond to the interrogatory with precise or approximate dates of conception and reduction to practice.