In determining the existence of patent infringement in Phillips Seafood Philippines Corp. vs. Tuna Processors, Inc., G.R. No. 214148 (06 February 2023), the Supreme Court applied the literal infringement test and doctrine of equivalents test, and introduced the all elements test into Philippine jurisprudence. Furthermore, it emphasized that the extent of protection granted to patent holders is limited to the claims of their patent.
Claiming to be one of the patentees of Philippine Patent No. I-31138 entitled “Method for Curing Fish and Meat by Extra Low Temperature Smoking”, Tuna Processors, Inc.’s predecessor-in-interest filed a complaint for patent infringement against Phillips Seafood Philippines Corporation before the Intellectual Property Office. Patent I-31138 covers “…the process of curing tuna meat by exposing it to a filtered smoke cooled in a cooling unit to between 0° and 5°C while retaining ingredients exerting highly preservative and sterilizing effects.” Phillips Seafood Philippines Corporation, on the other hand, raised the invalidity of Patent No. I-31138 and claimed that unlike Patent No. I-31138, its process of curing tuna meat does not require a cooling unit.
First, the Supreme Court clarified that the burden of proof rests on Tuna Processors, Inc. and its predecessors-in-interest. As a general rule in patent infringement, the burden of proving patent infringement rests on the plaintiff. However, for process patents, the Intellectual Property Code creates a presumption that an identical product was obtained from the patented process if (a) the product is new or (b) there is a substantial likelihood that the identical product was made by the process and the patentee was unable, despite reasonable efforts, to determine the process actually used. Since (a) smoked tuna fish is not a new product, and (b) the use of filtered smoke cooled to between 0° and 5°C is not the only way to produce smoked tuna fish, the Supreme Court ruled that the burden of proving that the process to obtain the identical product is different from the patented process rests on the defendant, Tuna Processors, Inc.
The Supreme Court then applied the literal infringement test and the doctrine of equivalents test to determine the existence of infringement. Under the literal infringement test, courts consider the elements of the invention as expressed in the claim(s). If the allegedly infringing product or process falls within the literal meaning of the claim(s), there is patent infringement. On the other hand, under doctrine of equivalents test, the courts consider whether the elements in the allegedly infringing product or process are equivalent to the elements expressed in the patent’s claim(s). There is patent infringement if the allegedly infringing product or process appropriates the innovative concept of the patent, and despite the modifications introduced in the infringing product or process, it still performs substantially the same functions, in the same way, to produce the same result.
Significantly, the Supreme Court introduced the all elements test, derived from the U.S. case of Warner-Jenkinson v. Hilton Davis, 520 U.S. 17 (1997). It is supported by Section 75.2 of the Intellectual Property Code which states that in determining the extent of protection conferred by a patent, elements in the allegedly infringing device or process which are equivalent to the elements expressed in the claims should also be considered. Accordingly, the doctrine of equivalents must be applied to the individual elements—not to the invention as a whole.
Applying the literal infringement test, the Supreme Court found no literal infringement because Phillips’ process does not fall within the literal meaning of Patent I-31138’s claims. The elements of cooling the filtered smoke to 0° and 5°C in a cooling unit before applying it to the tuna meat are absent. Similarly, the Supreme Court found no infringement under the doctrine of equivalents test because, although the function and result of the processes are substantially the same, the means used by the parties to cure the tuna meat are different. Finally, Supreme Court found no infringement under the all elements test. The equivalents of all the elements in Patent I-31138 are not present in Phillips’ process.
In sum, the Supreme Court held that Tuna Processors, Inc. and its predecessors-in-interest failed to discharge their burden of proving that Phillips appropriated the innovative concept of Patent I-31138. The evidence on record is insufficient to establish that Phillips’ process cures the tuna meat in substantially the same way as Patent I-31138.