Estopped by your patent claims
In patent law, you are bound by your own claims. The precision of words determines the breadth of protection.
Daily TribuneIn patent law, you are bound by your own claims. The precision of words determines the breadth of protection.
The Supreme Court, in Phillips Seafood Philippines Corp. v. Tuna Processors Inc. (TPI), once again underscored the pivotal role of patents in promoting national development and economic growth.
Patents, the Court reminded, are not mere monopolies but instruments that encourage the flow of knowledge by rewarding innovation. By granting inventors market exclusivity — the right to exclude others from making, using, selling, or importing their inventions — the law stimulates disclosure, ensuring that society benefits from creative discoveries.
Yet, as the Court emphasized, this exclusive right is not boundless. Like any other form of intellectual property, the protection granted by a patent is confined strictly to what is claimed. The claims define the metes and bounds of the inventor’s dominion. One cannot claim more than what is described — and neither can courts expand the coverage beyond what the patentee has clearly stated.
The controversy stemmed from TPI’s Patent I-3113811, titled “Method for Curing Fish and Meat by Extra Low Temperature Smoking.” TPI alleged that Phillips infringed upon its patent by using a similar process in curing its tuna products.
To determine infringement, the Supreme Court reviewed the findings of the Intellectual Property Office of the Philippines (IPOPHL), which compared the processes used by both parties.
TPI’s patented process consisted of: Burning or smoking material at 250° to 400°C; filtering the smoke to remove tar; cooling the filtered smoke to a temperature between 0° and 5°C while retaining ingredients with preservative and sterilizing effects; and smoking the tuna meat by exposing it to cooled, filtered smoke.
Phillips’ process, on the other hand, involved: Burning sawdust at 250° to 400°C; filtering the smoke to remove tar, odor, and other impurities; cooling the filtered smoke only to ambient temperature; exposing the frozen tuna meat to the filtered smoke by both smoking and direct injection; and cooling the smoked meat to 4°–5°C before inspection.
At first glance, the two methods may appear similar. But as the Court noted, the difference lies in the temperature and manner of application — details that are vital in determining patent infringement.
The Supreme Court took the occasion to elucidate the role of claims in patent law. Claims, it said, serve a dual purpose: they define the scope of protection granted to the inventor (definitional function) and notify the public and the courts of the extent of that protection (public notice function).
Thus, claims must be clear, concise, and supported by the description. They may take the form of either process claims (covering activities involving the use of materials) or product claims (covering compositions, apparatuses, or systems). Moreover, claims may be independent — defining the invention on their own — or dependent, referring back to and limiting another claim. Importantly, a dependent claim is only infringed if all the features of the claim it depends on are also infringed.
In short, the boundaries of a patent are drawn by its own words. Courts cannot stretch the protection beyond what the patentee expressly delineated.
Applying these principles, the Court found that while the first two steps of Phillips’ process resembled those in TPI’s patent, the subsequent steps diverged significantly in function, means, and result. The smoke in Phillips’ process was cooled only to ambient temperature, not between 0° and 5°C as claimed in TPI’s patent. Moreover, Phillips introduced an additional step — injecting the smoke directly into the tuna meat — which was not part of TPI’s claimed process.
In the end, the Court concluded that there was no infringement, as Phillips’ process fell outside the scope of TPI’s claims.
The lesson is simple yet profound: In patent law, you are bound by your own claims. The precision of words determines the breadth of protection. Inventors, like drafters of contracts, must choose their language carefully — lest they be estopped by their own claims.
For more of Dean Nilo Divina’s legal tidbits, please visit www.divinalaw.com. For comments and questions, please send an email to cad@divinalaw.com.