By Dennis Crouch
Magsil Corp. and MIT v. Hitachi (Fed. Cir. 2012)
In a unanimous opinion, the Federal Circuit has affirmed a district court summary judgment holding that the asserted claims of MIT's patent are invalid for a lack of enablement. The patent covers read-write sensors for computer hard disk drive storage systems and relies upon quantum tunneling in operation.
The courts have derived an enablement requirement from Section 112 of the patent statute. Under the doctrine, after studying the patent specification, a person of skill in the relevant art should be able to (theoretically) make and use the full scope of the claimed invention without undue experimentation. Patents ordinarily include many different claims that identify various legal rights given to the patentee. Enablement is judged independently on a claim-by-claim basis. Any claim that lacks enablement will be deemed invalid and thus unenforceable.
One of the murkiest areas of the doctrine is determining whether the "full scope" of the claim is enabled. The commonly used open ended "comprising" claim language allows for an infinite number of potential variants to be embodied within the scope of a single claim. In almost every case, it is possible to theoretically define an embodiment that falls within the claim scope but that is not fully enabled by the specification. Obviously, the fact that a particular theoretical covered embodiment is not enabled can't be sufficient to invalidate a claim. The difficult legal issue then is finding when a patent claim crosses the threshold from legitimately having a few non-enabled potential embodiments to illegitimately failing to enable the full scope of the claim.
Unbounded Range: Here, the patent claims that the device switch has a change in resistance of "at least 10%." Although it is desirable to have a device with a greater ΔR, the inventors best pre-filing device only reached 11.8%. The accused infringing devices had a greater ΔR and thus the patentee argued that the "at least 10%" claim scope could cover a ΔR of 100% or even 1,000%." The defendant (Hitachi) was able to prove that those ΔR levels could not have been achieved at the time of the patent filing without undue experimentation. The Federal Circuit found this sufficient to find the claim lacking enablement.
In sum, this field of art has advanced vastly after the filing of the claimed invention. The specification containing these broad claims, however, does not contain sufficient disclosure to present even a remote possibility that an ordinarily skilled artisan could have achieved the modern dimensions of this art. Thus, the specification enabled a marginal advance over the prior art, but did not enable at the time of filing a tunnel junction of resistive changes reaching even up to 20%, let alone the more recent achievements above 600%.
This case follows in re Fisher (CCPA 1970). In that case the court ruled that a claimed potency of "at least 1 International Unit of ACTH per milligram" was invalid as lacking enablement after the patentee attempted to enforce the patent against products with potentials of much greater than the 2.3 IUs disclosed in the specification.
The court particularly addressed the comprising issue discussed above. One key distinction is that the high ΔR range here is an explicit element of the claimed invention rather than being a mere latent vestige of the claim structure.
Not a Groundbreaking Invention: In both Fisher and here, the patentees' actual experiments were at ranges just above that already known in the art. That seeming small advance reflected in claiming a range that barely avoided the prior art at the lower bound but then attempted to claim an infinite range at the upper bound. In this case, the court identifies the advance as "marginal over the prior art." The suggestion from the court is that a marginal advance such as this is deserving of a much narrower scope than would be given a groundbreaking invention. The court is on the right track with this approach however, the language of the opinion can also be read to limit potentially broad scope of even groundbreaking inventions when the accused infringer (or others) have spent significant time and energy on developing a particular embodiment covered by the invention.
Whither Open-Ended Ranges and a Plurality of Members?: The opinion can also be read to eliminate the potential for open-ended ranges. The court writes that "the '922 patent specification only enables an ordinarily skilled artisan to achieve a small subset of the claimed range." Of course, a mathematician will explain that any claim with a range that potentially reaches to infinity (e.g., "a plurality of members") will suffer from this same defect – that only a small subset of the claimed range will be enabled (assuming that infinity is not enabled).
Transformative Research to Avoid Infringement: As mentioned above, the opinion relies somewhat heavily on the fact that extensive post-patent-filing research was conducted; and that the research eventually led to a new state-of-the-art that is much more advanced than that imagined by the inventors (even though still literally covered by the claims). This opens the door to manufacturing companies to offer testimony related to their extensive research and development programs and offer an argument akin to transformative copying in copyright law. If the research is sufficiently transformative (and took sufficient effort) then the patent will be deemed invalid for failing to enable that covered embodiment.
Enablement Doctrine Allows Follow-on Research: The court is straightforward in stating that a strong enablement requirement will help prevent over broad patent claims and thus allow room (and incentives) for "follow-on or improvement inventions."