Will changing the product 10% to 30% avoid patent infringement?
I think part of the reason why patents are undervalued these days is the growing myth that you can avoid infringing a patent by changing your product by, say, 10% to 30% (what does a 10-30% product modification even mean?). Unfortunately, such percentage changes will not suffice especially when utility patents are involved. You must understand how patent claims work in order to know how to avoid patent infringement.
Let’s the set the record straight. There is no such rule about any percentage modifications that would avoid patent infringement. Technically, infringement is not about how different your product is from the patent. In fact, your product may seem very different, yet still infringe. Infringement is all about the claims, and avoiding infringement is about omitting what’s in the claims (not adding or changing).
To analyze infringement, you must check each independent claim in the patent and see if each claim feature is found in your product. If an independent claim is not infringed, then logically a dependent claim cannot be infringed. In contrast, invalidating an independent claim does not necessarily invalidate a dependent claim.
Suppose a utility patent (not a design patent or a pending application) contains two independent claims: Independent Claim 1 includes a combination of features, or claim limitations, AB while Independent Claim 2 recites a combination of BC. Let’s assume you’re thinking of launching a product with features ABCD.
In the above example, your product would infringe both Claim 1 because it has A and B, and Claim 2 because it has C and D. Notice how you do not avoid infringing Claim 1 by adding features on top of what is claimed. Notice also that percentage changes in the product have nothing to do with the infringement analysis.
Let’s assume you redesign your product so that it contains features A and C only. In this case, you would avoid infringing both Claim 1 – because B is missing – and Claim 2 – because D is missing.
Doctrine of Equivalents
So far, we have been discussing literal infringement, but the analysis does not stop there. The doctrine of equivalents (DOE) must also be considered even if your product does not literally infringe. If a claim limitation is missing from your product (thus, no literal infringement), you still have to consider whether your product might include a feature that is equivalent to that missing claim limitation. The DOE can be a tricky gray area which deserves a separate discussion.
If a patent has expired, can you make the formerly patented product?
Unfortunately, the short answer is maybe. The reason why the answer is not an unequivocal yes is because other live patents may still cover different parts, features or combinations found in your patent. The only thing certain about an expired patent is that the dead patent cannot be asserted against you. However, this does not automatically mean that you’re free and clear to make products once covered by the expired patent. A hypothetical may help.
Hypothetical: patent claiming ABC expires and you want to sell product ABC
Suppose a patent claiming a combination of three features A, B and C has expired. You now wish to sell a product containing ABC. You can be certain that the owner of the dead ABC patent will not be able to enforce the expired patent against you (unless they’re able to revive the patent by, for example, paying a late maintenance fee). However, there may still be live, unexpired patents covering other features and combinations thereof.
For example, suppose there’s a patent claiming AB and another patent claiming BC and both patents haven’t yet expired. Your product would infringe the AB patent and the BC patent since your product contains those claimed features. The same would be true if there were unexpired patents claiming, for example, A alone or B alone.
Consider a Freedom-To-Operate Search
As shown above, it’s possible that a product covered by a dead patent may still infringe other live patents. If you want to reduce uncertainty and gauge the risk of patent infringement associated with a particular product, consider a Freedom-To-Operate (FTO) search which would seek to uncover live patents claiming features found in your product.
Even if you find that your original version of a product may infringe certain patents, the benefits of an FTO search include the possibility of designing around those patents by modifying your product to omit certain features. You may end up with a safer updated version of your product carrying a lower risk of infringement.