The assessment of inventive step is of paramount importance in examining patent applications. Very often, examiners have to assess the inventive step of a claimed invention in view of multiple references. The rules in the Patent Examination Guidelines ("Guidelines") regarding the determination of patentability based on multiple references are as follows:

If a claimed invention could have been easily made by combining, modifying, substituting or adapting the teachings of one or more prior art references in view of the common knowledge at the time of filing, then the claimed invention as a whole is obvious. In that case, the examiner should determine that the claimed invention can be easily arrived at.

Because of these rules, examiners treat prior art references as if they were pieces of a mosaic and combine them without indicating which reference is the primary reference. Moreover, examiners often ignore the "teaching away" of the prior art. These practices result in many findings based on hindsight.

At a recent conference held by the Intellectual Property Court, the representative from the Intellectual Property Office ("IPO") discussed possible amendments to the Guidelines to avoid findings based on hindsight. The proposed amendments would clearly define the technical level of a person having ordinary skill in the art ("PHOSITA") at the time of filing and would provide principles to help examiners give objective reasoning based on available evidence. The proposed amendments are expected to make patent examination less subjective. The proposed amendments cover the following areas:

  1. Definition of PHOSITA

According to the Guidelines, a PHOSITA as a hypothetical person. However, technological development often involves interdisciplinary knowledge and requires the efforts of a group of persons (such as an R&D or manufacturing team) rather than a single person. Therefore, the IPO plans to adopt the European standards and amend the definition of PHOSITA in the assessment of inventive step to mean a group of skilled persons from different fields.

  1.  Identification of primary reference

The IPO plans to require examiners to choose the closest prior art reference or the most appropriate prior art reference as the primary reference. This requirement would enable the examiners to determine a starting point for examination.

  1. Steps and factors in inventive step assessment

Under the proposed amendments, examiners should, in assessing inventive step, consider the following factors when determining whether there would be motivation to combine two or more references:

  • whether the references relate to the same field
  • whether the technical problems addressed by the references are the same or related
  • whether the effects/functions of the references are the same or related
  • the teachings or suggestions of the prior art that are related to the claimed invention

If it is determined that there would be motivation to combine two or more references, then the examiner should proceed to determine whether the claimed invention yields unexpected results.

Like their Japanese counterparts, IPO examiners would be required to take into account any "blocking factors" (that is, the "teaching away" of the prior art) in determining whether two or more references are combinable. The blocking factors could include the following:

  • The purpose of the secondary reference(s) is opposite that of the primary one.
  • It is determined that the combination of the primary reference and the secondary reference(s) would render the invention of the primary reference inoperable.
  • The teachings of the secondary reference are incompatible with those of the primary one.
  • It is already documented in the art that the teachings of the secondary reference(s) cannot be combined with those of the primary reference, and thus the PHOSITA would not consider such a combination.

It is believed that the above amendments, if adopted, would improve the quality of inventive step assessments.