The defendant in a Taiwan patent civil lawsuit can argue the patent invalidity, say, lack of novelty or inventive step, and the civil court should determine whether the patent is valid. The Supreme Court made a judgment in November 2024 (2024 Tai Shang Zi No. 459) with respect to the court’s review of inventive step, not only reiterating the requirement of considering the technical levels of a skilled person, but also highlighting that the “primary prior art” should be determined first if the defendant provided combinations of multiple prior art references.
In the cited patent litigation, the patent-in-suit is a systemized method of programming a control device, comprising six steps of setting up and filling in data fields. The plaintiff asserted that the defendant’s controller and software development tool constituted an infringement. As its main defense strategy, the defendant provided multiple prior art references and argued that the combination of said references can prove the patent-in-suit invalid. However, each of the prior art references presented by the defendant disclosed only part of steps of the patent-in-suit, and both parties’ disputes focused on whether the skilled person can easily accomplish the invention of the patent-in-suit based on such prior art references. This case went through several adjudications. The Taiwan Intellectual Property and Commercial Court (hereinafter referred to as the “IPC Court") originally held that the patent-in-suit lacked inventive step and ruled against the plaintiff in both first and second instances. Dissatisfied with the judgments, the plaintiff appealed to the Supreme Court. The Supreme Court made a judgment (2022 Tai Shang Zi No. 186) in August 2022 to nullify the original judgment and remand it back to the IPC Court for the reason that the original trial did not investigate the technical levels of a skilled person at the time of filing the patent application, since this would affect whether the skilled person can modify, replace, change, or combine the prior art references. Furthermore, the original judgment did not holistically consider the secondary consideration factors, such as solving a long-felt but unresolved problem, and the commercial success facts about obtaining license, to avoid hindsight. Nevertheless, on remand, the IPC Court maintained that the patent-in-suit lacked inventive step and the plaintiff appealed again.
Responding to the appeal, the Supreme Court made the aforementioned judgment, 2024 Tai Shang Zi No. 459, nullifying the IPC Court’s retrial judgment and remanding the case back to the IPC Court again. This time, the Supreme Court pointed out that when examining the inventive step, the IPC Court did not first determine “primary prior art” from the multiple prior art references provided by the defendant, and defined the “primary prior art” as the “single prior art reference” that is expected to provide the best basis for the invention and disclose the technical information on which a skilled person can base to accomplish the invention most likely. The Supreme Court also stated that when determining inventive step, there should be a comparison on the difference between the “primary prior art” and the invention patent, and should consider whether a skilled person can easily accomplish the invention based on the contents disclosed in relevant prior art, rather than simply aiming at the individual component or step of the invention patent, by mechanically extracting the corresponding disclosed contents of each prior art references and then aggregating or combining them, to avoid revealing in hindsight. Therefore, the Supreme Court criticized the IPC Court for inferring that the patent-in-suit lacked inventive step merely because each prior art reference has disclosed part of elements of the patent-in-suit, while failing to determine the “primary prior art” at first. In addition, the Supreme Court also referred to the “could-would approach” in European patent practice, explaining that when determining the inventive step, it can also consider whether a skilled person is possible and willing to accomplish the invention by referring to the prior art.
The patent-in-suit in this case was granted and published in February 2001. At that time, the Patent Examination Guidelines of the Taiwan Intellectual Property Office (hereinafter referred to as the “TIPO") did not have relevant provisions on “primary prior art” for combination of multiple prior art references. TIPO incorporated this provision in its 2017 edition of the Patent Examination Guidelines. In addition, the Supreme Administrative Court, in its judgments, such as 2020 Pan Zi No. 355, has affirmed that the difference between the “primary prior art” and the patent being filed should be considered when determining inventive step in invalidation actions. Under the current administrative litigation practice of the IPC Court, it has been common for judges to require the parties to specify which of multiple prior art references should be considered as the “primary prior art.” As for civil patent litigation, it is worthwhile to observe how the Supreme Court’s opinion on the “primary prior art” and even the could-would approach regarding inventive step in this judgment will be responded or handled by the IPC Court in other civil patent litigation cases in the future. For a defendant arguing that a patent lacks inventive step based on a combination of multiple prior art references, it is recommended that the defendant should make preparations in advance. From the perspective of defending the patent’s inventive step, the plaintiff may consider how to effectively use the points raised in the Supreme Court’s aforementioned judgment in litigation.