A common misconception among many Australians is that patent infringement may be avoided by changing a patented invention by 10% (or by some other similar percentage). This is completely incorrect, as there is no formula or percentage of similarity to determine patent infringement.

It is unclear how it could be possible to change an invention by a particular percentage. For example, if an invention was a dining table, would it be considered changed by 10% if the legs were lengthened or if one leg was removed altogether? These types of slight design variations wouldn’t normally avoid infringement of a properly prepared patent, if an infringement occurred in the first place.

Patent infringement is defined as the unauthorised exploitation of an invention that is the subject of a granted patent, and includes actions such as; making, hiring, selling (or offering to make, hire and sell), using or importing the patented invention. Unauthorised exploitation occurs when a patented invention is exploited by a person other than the patentee, a licensee or authorised personnel. The general test for infringement is whether all essential elements of a valid claim of a granted patent have been taken.

Patent infringement is assessed on a country by country basis. Therefore, determining whether patent infringement has occurred involves an assessment of whether a granted patent exists in the jurisdiction where infringement is likely to occur. For instance, it is only possible to infringe an Australian patent in Australia. If a patentee has a granted US patent, but no equivalent Australian application was ever filed; any party may exploit the invention disclosed within the US patent in Australia without fear of patent infringement.

In addition, it is only possible to infringe a patent that is granted and still in force. As a result, if a patentee had an Australian patent expire at the end of its term, or that lapsed prior to the end of its term (subject to certain conditions), infringement of the expired or lapsed patent is not possible.

If these situations do not apply, and an in-force patent exists in the country in which the infringement would occur, then the scope of protection provided by the patent must be assessed. This is done through careful consideration of the claims within that patent. Specifically, if a product takes each and every feature of even a single claim of a patent, infringement will occur. Conversely, a product will not infringe a claim if even a single feature of that claim is omitted from the product. Therefore, avoiding patent infringement is about ensuring that your product omits features of the patented invention as claimed in the patent specification.

It is worth noting that having a patent for a product is not a guarantee that the exploitation of your product will not infringe an earlier patent.

Swift action is important when responding to a claim of patent infringement. Typically the lawyer or patent attorney’s letter will ask for a response within a few weeks. If you are accused of patent infringement, engage a qualified patent attorney or IP solicitor well within this response period so that they can work with you to provide a timely and professional response. Don’t simply ignore the letter, as this may leave the patent owner little choice but to escalate the matter to litigation. The solicitor or patent attorney will typically check that there is in fact a valid, enforceable patent and whether your actions constitute an infringement of the patent. You may seek to negotiate with the other party, or, if possible, you may challenge the validity of the patent and potentially continue to use your product or process.