Mondis Tech. Ltd. v. LG Elecs. Inc

Authored by: Jeremy J. Gustrowsky

In a significant decision for patent law, the Federal Circuit Court of Appeals reversed a $14.3 million damages award against LG Electronics, holding that key claims of U.S. Patent No. 7,475,180—owned by Mondis Technology Ltd. and Maxell—were invalid for lack of an adequate written description. The patent covered a system for controlling display units, such as computer monitors or televisions, and specifically claimed an “identification number for identifying at least a type of said display unit.” This phrase was added during prosecution to overcome prior art, but the court found that the original patent application did not support this broader claim.

The court explained that a patent’s written description must clearly show that the inventors actually possessed the full scope of what is claimed, as of the filing date. In this case, the patent’s specification consistently described a system where each identification number corresponded to a specific device, not a type or class of devices. Even Mondis’ own expert admitted that the patent did not expressly describe an identification number for identifying a type of display unit. The court found that there was no substantial evidence for a reasonable jury to conclude otherwise.

Mondis argued that the presumption of patent validity and the fact that the patent examiner allowed the amendment should have been enough to uphold the claims. However, the Federal Circuit clarified that sometimes the patent’s own language is clear enough to show that the required written description is missing, and that examiner allowance alone is not proof of compliance with the law. Because the claims were invalid, the court also ruled that issues of infringement and damages were moot.

This decision underscores the importance of ensuring that any amendments to patent claims during prosecution are fully supported by the original disclosure. Patentees cannot rely on broadening their claims after filing unless the original application clearly supports the broader scope. The ruling serves as a reminder for both patent applicants and litigators to carefully consider the written description requirement under 35 U.S.C. § 112.