Claims are sometimes drafted or amended to include negative limitations, such as “irrespective of a position at which a touch is detected.” The MPEP makes clear these features are not necessarily indefinite. MPEP 2173.05(i). In addition, my US prosecution study group recently discussed, in the context of negative limitations, potential problems of written description support under 35 USC 112(a) and possible difficulties in overcoming obviousness rejections under 35 USC 103.
Negative limitations can provide an additional issue for patentees. Specifically, these features can spell out a way for competitors to improve the product while possibly avoiding liability for infringing the patent.
For example, the study group considered an application directed to an electronic device with a touch screen. The Applicant had amended the claims to include a feature along the lines of “performing an action, irrespective of the position at which the touch is detected.”
Let’s assume this Applicant’s competitor wanted to avoid liability for a similar product. In this case, the competitor might offer a product that performs the appropriate action, while considering the position at which a touch is detected. For example, perhaps the competitor’s electronic device displays a button for performing the action, so that the user does not inadvertently trigger the action. Thus, in the competitor’s device, the action is performed respective of the position at which the touch is detected.
In this scenario, it might be difficult for the Applicant/Patentee to argue the competitor infringes the patent. Meanwhile, the Applicant has invested in the costs of the intellectual property, while also giving a competitor a roadmap to an improved product that might not infringe the intellectual property.