TIPS^®  Taiwan Intellectual Property Special

Application of “All Element Rule” and “Doctrine of Equivalents” in Determining Patent Infringement

The TIPO explained the relationship in applying “All Element Rule” and “Doctrine of Equivalents” to patent infringement cases on April 13. The TIPO illustrated that the “All Element Rule” is used to determine whether the accused item is within the literal meanings of the issued claims. Comparing the number, composition, and function of each corresponding element, if the elements of the accused item are all the same with the issued claims, it’s literal infringement. Then, applying Reverse Doctrine of Equivalents to determine whether the accused item was achieved by a way, or method/process, other than the issued claims. If not, and there is no Prosecution History Estoppel applied, the accused item is determined to be the same as the issued claims.

On the other hand, if there is no literal infringement, Doctrine of Equivalents will be applied to determine whether the accused item uses the same way to achieve the same function and produces the same result as the issued claims. If the differences are insubstantial and there is no Prosecution History Estoppel, the accused item is determined to be equivalent to the issued claims.