To avoid patent infringement, you need to review the claims of the utility patent and design around the claims of the patent. You have to ensure that you are not infringing the claims directly and indirectly.
What is direct infringement?
Direct infringement exists where a product or process incorporates all of the elements of an independent claim of the patent. You can locate the claims at the back of the patent. Independent claims are claims that do not refer to another claim.
The independent claim in a patent may have the following format.
1. An apparatus comprising:
Element B; and
Products that incorporate Elements A, B, and C literally infringe Claim 1. Conversely, products that incorporate less than all of Elements A, B, and C do not literally infringe Claim 1. For example, a product that incorporates Elements A and B but not C does not literally infringe Claim 1. As such, to avoid literal infringement of a patent, one must not literally practice (i.e., make, use, offer for sale, or import) all of the limitations recited in the independent claims of the patent.
However, even though a claim of the patent is not literally infringed, infringement can still be found under the Doctrine of Equivalents (a.k.a. DOE). This doctrine stands for the proposition that even if a product does not literally infringe a claim because it does not incorporate one or more of the elements of the claim, infringement can still be found if the product or process incorporates a feature that is insubstantially different with respect to the missing element. As such, a product that incorporates Elements A and B and a feature that is insubstantially different with respect to Element C still infringes the patent under the Doctrine of Equivalents.
To determine whether the element can be broadened under the doctrine of equivalents, the communications between the patentee and Patent Office must be reviewed to determine whether there are any statements or claim amendments that would prevent or limit the application of the Doctrine of Equivalents. The law would not permit a patentee to make statements to the Patent Office that D is a substantial difference compared to element C during a review at the Patent Office but argue during litigation that D is actually an insubstantial difference.
Hence, to avoid infringement of a patent, changes to a product or process must be made to avoid literal infringement and infringement under the Doctrine of Equivalents.
Myth: The percentage difference between a product with a patented product does not indicate whether the product infringes on claims of the patent. Patent infringement is found either literally or under the Doctrine of Equivalents.
What is indirect infringement?
Indirect infringement occurs when (1) when one actively induces another to infringe a patent or (2) when one offers to sell … or imports … a component of a patented machine … for use in practicing a patented process, constituting a material part of the invention, knowing the same to be especially made or specially adapted for use in an infringement of such patent, and not a staple article or commodity of commerce suitable for substantial non-infringing use.
How do you design around a claim of a patent?
To design around a claim of a patent, you need to find an element or limitation in the claim which is not necessary to the function of the claimed invention. Once you locate this element or limitation, you can remove it from your product yet still retain the functional aspects of the claimed invention.
To prevent easy design arounds, the claims of your patent need to be focused on the point of novelty of the invention. That way, all limitations are necessary for the function to exist.
I invite you to contact me with your patent questions at (949) 433-0900 or [email protected]. Please feel free to forward this article to your friends. As an Orange County Patent Lawyer, I serve Orange County, Irvine, Los Angeles, San Diego, and surrounding cities.