It has always been a challenge to determine whether an invention of a patent specification, when compared with prior art references, has an inventive step. This is because only when no prior art is found identical with the invention will the process of determining patentability enter the phase of "inventive step." During examination of inventive-step, the invention has to be compared with prior art references to determine whether any person having ordinary skill in the art (hereinafter referred to as a "PHOSITA") at the time of filing the patent application is able to complete the invention merely through simple modifications to prior art references. In a cancellation action procedure, to demonstrate that a PHOSITA can easily complete the patented invention, the cancellation petitioner often cites two or even three prior art references to support his/her arguments, usually stating that a PHOSITA can easily combine and/or adapt such references.

However, recent court practice requires that when combinations of two or more prior art references are asserted against the inventive step of an invention claimed by a patent, the cancellation petitioner needs to provide proof or an explanation that the PHOSITA is indeed "motivated" to combine multiple prior art references. According to the Patent Examination Guidelines since 2013 (hereinafter referred to as the "Guidelines"), it shall be determined by taking into consideration the following matters as to whether a PHOSITA is motivated to make obvious combinations of relevant prior art references by said disclosure of the relevant prior art references and by utilizing the ordinary skills at the time of filing:

(1) Any connection between prior art references and the invention patent in terms of their technical fields;

(2) Any connection between prior art references and the invention patent in terms of the problem intended to be solved;

(3) Any connection between prior art references and the invention patent in terms of their functions or effects;

(4) Any teachings or suggestions relevant to the invention patent included in prior art references.

The Guidelines further state that the absence of any of the above four matters does not necessarily lead to the conclusion of lacking the motivation to combine the prior art references.

However, should it be that a PHOSITA is motivated to combine multiple prior art references as long as one of said matters is satisfied by prior art references and the invention patent,, the Guidelines is silent about this.

As for specific criteria that should be adopted to determine whether a PHOSITA is motivated to combine prior art references to complete an invention, the IP Court (IPC) provides opinions in its 2016-Xing-Zhuan-Su-Zi-No. 65 judgment delivered in May 2017. The case involved a cancellation action followed by an administrative suit. The target patent that the cancellation action was filed against relates to the position of the rear seat pedals of a motorcycle (hereinafter after referred to as "the invention in question"). The cancellation petitioner cited two prior art references relating to motorcycles (hereinafter referred to as the "cited references") and argued that any PHOSITA can easily complete the invention in question by combining the cited references. Both prior art references disclose a motorcycle with rear seat pedals, but the positions are different from that specified in the claim (i.e., the invention in question) of the target patent. Though the target patent relates to modification of common mechanical structures, the IPC holds that a PHOSITA cannot obtain any motivation on the basis of the cited references to combine them and thereby easily complete the invention in question. A summary of the IPC’s opinions is as follows:

1.For inventive-step examinations, one should evaluate, by rigorously referring to technologies or knowledge disclosed in the cited references and taking into account technical content of the invention in question together with its purposes of invention and functions, whether the invention in question has overcome difficulties in choosing or combining prior art references and thus acquired outstanding technical features or an obvious inventive step. It is a violation against principles of inventive-step judgment to conclude without any careful review of the cited references and merely on the ground of what is disclosed in the patent specification that technical features of tandem foot pegs (i.e. pedals) of the invention in question can be easily conceived of.

2.The objective of the invention in question is for passengers to feel more comfortable when riding on the rear seat and resting their feet on the pedals, while that of the first prior art reference's purpose is to improve foot-peg comfort for motorcycle "riders," and that of the second is to prevent foot-peg struts from being too large. Therefore, the two prior art references differ from the invention in objective of invention and function.

3.Neither the first nor the second prior art reference discloses the positional features of the rear seat pedals specified in the invention in question.

4.The first prior art reference differs from the second in objective of invention and function. A PHOSITA would barely be motivated to combine the two references merely on the basis of the content of the two prior art references.

According to the Judgment, the IPC took the following steps to reach the conclusion: comparing the technical content, objectives and functions of the invention in question and prior art references in a comprehensive manner to confirm the degree of difference, then comparing the content of the two prior art references. Since the two prior art references differ from each other in their objectives and functions, they would barely motivate a PHOSITA to combine them to easily conceive of the invention in question.

It is always a challenge to avoid hindsight in determining whether an invention concerning modifications to common mechanical structures has an inventive step. The above IPC's opinions, i.e. rigorously cross-comparing the technical content, objectives and functions of prior art references and the invention in question, are of great reference value.