Reported / Citable
Background
In a patent infringement lawsuit, Defendant BOE Technology Group Co. (BOE) sought permission from the court to amend its “invalidity contentions”—the formal claims arguing why the plaintiff’s patent is invalid. BOE wanted to add two older projector models, the 5550c and the 810p, as examples of “prior art” that would invalidate the patent held by Longitude Licensing Limited.
BOE filed its motion after the court’s deadline for serving these contentions had already passed. It argued that the delay was justified because the older products were difficult and expensive to find and analyze. BOE claimed it had acted diligently by first focusing on more recent and accessible products before turning to the older projectors. The plaintiff, Longitude, opposed the motion, arguing that BOE had not provided an adequate reason for failing to search for this art before the deadline.
The Court’s Holding
Magistrate Judge Roy S. Payne denied BOE’s motion. The court analyzed the request based on three factors: the defendant’s diligence, the importance of the new evidence, and the potential prejudice to the plaintiff. While the court acknowledged that the new prior art was important for BOE’s defense—noting the 5550c projector would be its only prior-art basis for invalidating one of the patents—it ultimately found that BOE had not been diligent.
The court stated that while identifying system prior art can be difficult, parties cannot use that difficulty as an excuse to “skirt the Court’s deadlines by conducting searches for new products that only begin after the deadline.” Because fact discovery was set to close within a month and expert reports were due shortly thereafter, the court found that allowing the late amendment would prejudice Longitude by leaving it with insufficient time to respond to the new invalidity theories. Concluding that BOE’s lack of diligence and the prejudice to Longitude outweighed the importance of the new art, the court denied the motion.
Key Takeaways
- Courts require parties in patent litigation to be diligent in discovering and disclosing prior art before established deadlines.
- A strategic decision to delay searching for more difficult or expensive prior art does not excuse a failure to meet court-ordered deadlines for invalidity contentions.
- When ruling on a motion to amend contentions late, courts will weigh the moving party’s diligence, the importance of the new evidence, and the prejudice the delay causes the opposing party.
- Even highly important evidence may be excluded if the party seeking to introduce it was not diligent and the introduction would prejudice the opposing party at a late stage of the case.
Why It Matters
This order serves as a strong reminder that procedural deadlines in patent litigation are firm and that litigants must manage their discovery strategies accordingly. The Eastern District of Texas, a key venue for patent disputes, is known for strictly managing its docket. The court’s decision emphasizes that parties cannot justify missing deadlines by citing the cost or difficulty of their investigation, especially if they chose to delay that investigation for strategic reasons. This reinforces the principle that diligence is paramount, and a failure to act in a timely manner can result in the exclusion of potentially case-critical evidence, significantly impacting a party’s ability to present its defense.