Do I infringe a patent?

Registered patents are presumed to be valid (i.e. novel and inventive). However, whereas foreign patents are generally subject to examination before grant, South African patents proceed to grant without scrutiny.

When evaluating the validity of a patent, one searches for a document released to the public before the priority date of the patent that describes all the features claimed. Such document impacts the novelty of the patent. Failing this, one seeks prior documents that, when “mosaiced”, describe all the claimed features. These documents impact the inventiveness of the patent.

A feature is not considered inventive if its inclusion would have been considered obvious / “very plain” to “a person skilled in the art” (i.e. an expert in the field) having regard to all the material available to the public as at the priority date of the patent. Put another way: a feature is obvious if there is a reasonable probability that a person skilled in the art would take the step, such that the result is not unexpected.

The general perception is that our courts have historically set a low hurdle for inventiveness, having held only a handful of patents to be invalid on this basis.

In assessing inventiveness our courts have regard to the opinion of expert witnesses and the following factors:

  • the length of time and research required to arrive at the “inventive feature”;
  • evidence of commercial success, copying, displacement of competing products and recognition by industry of the “inventive feature”; and
  • whether the benefit associated with the “inventive feature” was detailed in the specification.

Ultimately, after the testimony of expert witnesses and presentation of secondary evidence, the issue of inventiveness is subjective and determined by the Judge.