Hamamatsu Corporation

I'll research this company and its litigation context.

Hamamatsu Corporation is the North American marketing and sales subsidiary of Hamamatsu Photonics K.K. (HPK), a Japanese photonics manufacturer. It is a New Jersey corporation headquartered at 360 Foothill Road, Bridgewater, NJ, and a wholly owned subsidiary of Photonics Management Corp., an HPK holding company (D. Mass. record, SiOnyx v. Hamamatsu). HPK was founded September 29, 1953, is based in Hamamatsu City, Shizuoka, Japan, and is listed on the Tokyo Stock Exchange Prime Market (code 6965). HPK reported consolidated net sales of ¥212.05 billion for the fiscal year ended September 30, 2025, and about 6,601 consolidated employees (4,262 at the parent). No separately published revenue or headcount exists for Hamamatsu Corporation itself.

Operations. HPK develops and manufactures photonic devices and systems. Its stated product lines are photomultiplier tubes, opto-semiconductors, imaging devices, light sources, imaging and analyzing systems, and laser equipment and components, sold into medical, manufacturing, analytical, measurement, and academic-research markets. Hamamatsu Corporation distributes HPK products in North America; HPK acquired Denmark-based NKT Photonics in 2024 and renamed it Hamamatsu Photonics A/S.

Litigation posture. This is an operating company, not an NPE. The two tracked matters are one plaintiff-side and one defendant-side case arising from the same dispute. Hamamatsu Corporation's sole "plaintiff" appearance is a defensive inter partes review petition at the PTAB, not an infringement suit; its defendant appearance is the resulting Federal Circuit appeal. Neither involves plaintiff-friendly venues such as the Eastern District of Texas; the underlying dispute was litigated in the District of Massachusetts.

Notable cases. In IPR2016-01910 (filed September 30, 2016), Hamamatsu Corporation challenged SiOnyx, LLC's U.S. Patent 8,680,591; the PTAB's March 28, 2018 final written decision invalidated many claims but upheld claim 26, and the Federal Circuit affirmed (Sionyx, LLC v. Hamamatsu Corporation, nonprecedential, April 3, 2019). The parallel litigation, SiOnyx, LLC and Harvard v. Hamamatsu Photonics K.K. et al. (1:15-cv-13488), concerned a 2007 NDA covering laser-textured "black silicon" photodetector technology. The Federal Circuit (SiOnyx, LLC v. Hamamatsu Photonics K.K., 981 F.3d 1339 (Fed. Cir. 2020)) affirmed transfer of the disputed U.S. patents to SiOnyx and reversed as to the foreign counterparts.