Prof. Robert P. Merges, University of California at Berkeley School of Law
September 5, 2014


Exclusive rights for new technologies, in order to promote innovation: that’s what the patent system is supposed to be about.  And at least sometimes, even today, it still is.  At times, to promote innovation today patents may be interpreted in a way that covers technologies that had not existed when the original patent was filed.  This is one instance of a more general issue in patent law: the division of legal rights (and profits) between original “pioneering” inventors and later “improvers.”  The classic theory in this general area – elegantly described by the economist Suzanne Scotchmer – shows that patent law can achieve a sort of magic balance, mixing incentives for a broad pioneering invention with incentives for the development of later or “after-arising” technologies (AATs).1  Patent law does and always has permitted patent claims to cover AATs; in some cases, it is considered appropriate.  The first-generation technology is so important and “pioneering” that patent law permits that first-generation patent claim to cover technologies not yet developed.

At the same time, patent doctrine has also evolved to be on the lookout for situations where claims improperly cover technologies not yet fully mature or developed.  Patent claims that in effect look too far ahead, in comparison to the actual teaching and disclosure of the patent itself, are viewed with suspicion.  They allow a patent owner to claim more than he deserves based on the actual research conducted.  This has been a prominent theme in the case law under what is known as the “written description” doctrine in patent law.  It is also a feature of some other legal decisions, because patent law actually has a number of rules and doctrines that can help guard against improper attempts to “claim the future.”

What is the current state of play with regard to attempts to “claim the future”?  And how well do current patent rules serve the purpose of promoting innovation – are they, in their current form, striking the right balance between pioneering inventors and improvers?  These are the issues I consider in this brief essay.

Current Case Law

One of the classic cases involving AAT is Hughes Aircraft Co. v. United States.2  In Hughes, the Federal Circuit considered infringement of a patent where significant advances in computer technology had occurred after the patents in the case had issued.  The smaller size and higher calculation capacity of second-generation computers allowed changes in the nature and location of calculations related to satellite positioning.  The patent’s claims covered the control of satellite orientation using commands from a ground control station.  The claims expressly required that the satellite provide the ground station with data sufficient to calculate an “instantaneous spin angle” (“ISA”) position.3  The ground crew would then make the necessary calculations and send a signal to the satellite to adjust its position.  Due to vast reduction in the size and vast improvement in the capacity of computer components, the accused devices were able to calculate the ISA position onboard the satellite.  The accused satellites transferred different information to the ground station because the onboard computer calculated ISA position.  Despite this “missing limitation” from the claims, the after-arising technology still permitted the ground crew to control the satellite.  The result was an insubstantial change in the way the satellites performed the claimed function.4  The AAT – smaller, faster computers – was said to be covered by the original (pioneering) claims.

Twelve years later the Federal Circuit saw a case that had many similarities.  It involved hearing aid technology that included software that adjusted the operation of the hearing aid depending on ambient acoustic conditions.  The original claims required the calculation of “filter coefficients” in an external host computer, and then transmission of the resulting values to the hearing aid itself.  A second generation of hearing aid technology evolved in which the coefficients were calculated right inside the hearing aid itself.  In considering a jury verdict finding infringement, the Federal Circuit, per Judge Rader, noted the similarity with Hughes:

In this case as well, advances in computer technology allowed the accused devices to relocate calculation and programming of filter coefficients from an external host controller into the hearing aid itself.  The accused devices “determin[e] the effect on the amplitude and phase” of acoustic feedback using onboard calculations.  ’850 Patent, col. 14, ll. 8-10.  While the improvement in technology allows Defendants’ products to constantly recalculate filter coefficients using electronics located on the hearing aid, the accused devices nonetheless perform the same function in substantially the same way, with substantially the same result claimed by the ’850 Patent, thus providing substantial evidence for the jury’s infringement verdict.5

These AAT cases have two key features.  First, they are centered around technologies that are in fact quite innovative.  The Hughes cases involved claims to an early geostationary orbital satellite, and the “attitude adjustment” feature of the claims involving positioning calculations was a key reason the satellites could stay in their orbits with such reliability.  Likewise in the hearing aid case, the adjustment of hearing aid performance using filtering coefficients was considered an important step forward in the field.

The second key feature is that the AAT in each case was a truly new development; it was unknown at the time of the original patent filing.  A number of cases show that patent doctrine is not nearly so accommodating of expansive claim interpretation when the alleged equivalent was in fact known at the time the original claim was drafted.6

Claiming Ahead on the Technological Trajectory

There is another variety of AAT case that comes out very differently from cases such as Hughes.  In these cases, claim drafters set out to cover “the next big thing” on the basis of some early, arguably preliminary, technological development.  The courts have been much less solicitous of this type of AAT case.  Under the written description doctrine, they have tended to hold that claims of this sort are invalid because they appear in patents that do not adequately describe the “over the horizon” technologies they claim.

One example is University of Rochester v. G.D. Searle & Co.7  In this case, university researchers discovered a mechanism – a cellular pathway – that was thought to hold significant promise as a new way to alleviate inflammation without causing the stomach upset associated with many analgesics.  The claims in the case were essentially of the form, “any anti-inflammatory drug that uses the pathway we have discovered.”  Some in the research community described these as “reach through” claims: they were an attempt to cover the as-yet-undiscovered drugs that were to be developed to take advantage of the discovered pathway.  The Federal Circuit invalidated the claims under the written description doctrine, pointing out that the patentees claimed a host of molecules that had not actually been identified as of the patent’s filing date.

The claims in Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co.8 were quite similar, and the Federal Circuit once again invalidated them.  The general thrust of the holding was, once again, that claims that are completely disproportionate to the information disclosed will not be tolerated.


What comes from these cases, I think, are three general points:

  • Truly pioneering inventions will be allowed to cover AATs.
  • But a technology in existence when a claim is drafted will be treated differently, since the patentee could have at least tried to cover it but in effect chose not to.
  • Attempts to explicitly claim “ahead” on a technological trajectory will be rejected, because to grant these claims would in effect award pioneering drafting rather than pioneering innovation.

Though these general rules have evolved without specific reference to the economic theory of pioneers and improvers, overall they are a reasonable approximation of how that theory might be applied to complex technologies involving patent claims.