The reverse doctrine of equivalents is a way for courts to find that an invention does not actually infringe on a patent even if it technically does. While the doctrine of equivalents expands the scope of the patent claims, the reverse doctrine of equivalents narrows their scope so that a new invention does not infringe even if it is substantially similar.
The reverse doctrine of equivalents is used only in cases where the new invention has significantly changed in principle but still falls under the literal claims of the patented invention. The courts use the reverse doctrine of equivalents to avoid finding infringement only if it would be very unfair or very detrimental to bar the new inventor from making his invention.
In determining whether or not to use the reverse doctrine of equivalents, a court will consider several factors:
- What is the actual scope of the patent? Does it cover the new invention?
- If so, should that patent extend to the new invention? This is the major issue that the reverse doctrine of equivalents must address. What is the fair scope of the patent?
- Has the new invention sufficiently transformed the original invention such that it should fall outside the scope of the patent of the original invention?
If you have questions or concerns regarding the reverse doctrine of equivalents, you may want to speak with a patent lawyer. An experienced patent lawyer can clarify the complicated patent system and can represent your interests in court if necessary.