As Lisa predicted a couple weeks ago, the Federal Circuit issued a new en banc (11-1) opinion today in Williamson v. Citrix without argument or further briefing. Patently-O has full coverage, so I'll get right to the core issue: the Federal Circuit reversed its prior precedent on functional claiming, but not all the way.
By way of background, if you claim a "means plus function" element (e.g., means for adding two numbers) then you need to disclose the structure for your means in the specification, which includes both the hardware and the algorithm (a general purpose computer programmed to take two numbers as an input, add them together, and report the sum as an output). If you don't put that structure in the specification, your claim is invalid as indefinite. Seem absurd for easy or common functions? More on that later.
The question is what you do when the word means is replaced with something else, like "module" or "unit" or "logic." The presumption has long been that this would not be means plus function, and it would be treated like structure unless the opposing party could convince the court that it really was a means plus function in disguise. Starting in about 2004, the Federal Circuit doubled down on this rule, making this a strong presumption against means plus function that was very difficult to overcome. As a result, the courts affirmed a bunch of patents that claimed functions but didn't actually teach how to do them. More on that later.
In this case, the court backtracked to pre-2004 rules. Rather than looking at the words, we look to see whether the limitation is really just claiming a means for doing a function, or whether the limitation has sufficient structure built right in. For example, you might have a limitation "adding module programmed to take two numbers as an input, add them together, and report the sum as an output." This is clearly functional, but the structure is right there in the limitation. Judge Reyna (along with some of my colleagues in the academy) would go further and argue that any functional claiming has to be in the specification, but I've never been convinced by that argument, in part because you can always put algorithms and structure right into claims. Judge Newman would have stuck with the formalistic requirement of requiring "means" to mean "means plus function," but it is clear that this view is currently disfavored.
My thoughts on what this all means after the jump.
I think the court's "new" rule (same as the old rule) is the right one. Where a claim includes a thing that performs a function but does not disclose the structure, then we should look to the specification for it and invalidate patents that don't disclose the structure. But surely it can't be that simple, and it's not. Below are some of my concerns with this ruling:
1. The Federal Circuit did a disservice by ever strengthening the presumption. This likely caused 10 years of patents to be written using different rules, and the change now potentially retroactively punishes people for following the present rules. That said, my concerns don't run too deep. First, many of the most suspect patents may have been written in the 1990s, during the first internet patenting boom, and the rules were different then. Second, the statute says what it says, and people who wrote ill-described patents were always at risk for written description problems if not means plus function problems. Indeed, in my own work, I tend to focus on written description as the primary problem.
2. There is still plenty of uncertainty in how this rule should apply. First, how much structure is enough? The announced rule is what a PHOSITA would think, so now there will be dueling declarations (maybe - the Federal Circuit here completely disregarded an expert opinion, instead relying on the intrinsic evidence). Second, how much structure is too much? Do we really have to describe an add algorithm? Every flow chart can be broken down into more steps, ad infinitum. Where do we stop? How do we know when we have enough structure?
3. While the strong presumption allowed bad patents to survive, this rule change will not suddenly make patents better, narrower, or improve the teaching of patents, etc. While proponents of the means plus function rule argue that it limits one to the specification, the statute says that it is the specification and equivalents. And while these equivalents have been narrowed starting in the 1990's, a rule that pushes more of the claim into the specification may be ripe for a broadening of what equivalents means. One point of the means plus function rule was supposed to keep patentees from being limited by their specific implementation, and yet people now argue that the rule is necessary in order to limit people to their specific implementation.
Knowing today's announced rule, consider how easy it would be to solve the drafting problem. In Williamson, the patentee's problem wasn't that the claim covered some specific solution that was being applied generally. The problem was that the offending "learning control module" was so simple that it didn't need real description, sort of like the add module above. The functions were: "receiving communications transmitted between the presenter and the audience member computer systems and for relaying the communications to an intended receiving computer system and for coordinating the operation of the streaming data module." The plaintiff pointed to figures that showed the input fields and the selection of the intended computer systems. Would it really have been so difficult to add a paragraph that said: "get data from audience client software and send data to a computer programmed to receive and process such data (and located at the address selected from the list)"? I doubt it. Everyone reading the patent knew how this worked, and solving the drafting problem would be quite easy. I suspect it would also not be very limiting - if another system were infringing, it would surely also be getting data from one computer and sending it to another.
Note that there are plenty of functions that are not so simply implemented, or where the invented implementation may really differ from today's application. This is a good reason to have the current rules. Thus, in the end, getting rid of the strong presumption is a good thing, and I think the long term impact will be better described patents and more non-infringement findings where the new technology significantly differs from the invention. But I don't think it is going to mean that patents will lose their potency; the ones most susceptible are already getting knocked out as abstract ideas anyway.
