A Win for Functional Claim Drafting - Openfield

Defining an invention solely in terms of a result to be achieved (colloquially termed "free beer" claiming) is a risky business and something that tends to prompt objections both at the EPO and UK IPO. When training to become a UK patent attorney, in my experience it is quite usual to practice drafting claim 1 using a combination of a few relevant structural features, something to define their relationship, and ending with some functional wording that defines what the purpose or result is. The functional type wording should ideally reveal or define the 'clever bit', i.e. the feature that would distinguish the claimed invention from whatever prior art turns out to be the closest. This doesn't always work though, because an examiner can find a closer piece of prior art than was known to the inventor at the time. However, when it does work it can result in a broader and potentially more useful patent claim. 

Because functional claiming can raise objections, it is always a good idea to provide clear fallback positions to more definite features so that the result to be achieved can instead be defined in terms of how the result is achieved if this becomes needed during prosecution. Examiners will often insist on this, particularly at the EPO (see e.g. F-IV 4.10 of the Guidelines for Examination). In the UK, functional claiming tends to be slightly more acceptable, being allowable so long as the specification provides "enough instruction for the skilled person to be able to achieve the desired result without embarking on a research programme" (MPP 14.72). It is therefore fairly common for UK drafted patent applications to have more free beer than applications drafted from a more continental perspective . However, given that the EPO is now considered the usual standard to aim for, it may be less common than it used to be. Examiners at the UK IPO, being more aware of practice emanating from the EPO, may also tend to look upon functional claiming less favourably than they might have done in the past. The practice remains common, particularly among the older elements of the UK patent profession. 

All that is an introduction to a recent decision (BL O/0369/26: Openfield) from the UK IPO regarding a UK patent application (GB2306083.3) defining an invention claimed partly in functional terms, and in which the functional part was the supposedly clever bit that distinguished it over the prior art. The latest version of claim 1 of the application reads as follows:

The claim defined a well logging tool of the type illustrated below (Figure 1 of the application), in which an articulated twin arm deployment arrangement would deploy by the arms hinging and extending away from the cylindrical body of the tool so that they then spanned the horizontal well bore. This enabled capacitive sensors along one of the arms to be positioned along the diameter of the bore to sense a level of water within the bore. The clever bit of the invention was to keep the capacitive sensors vertical as the arms were deployed, all other components of the claimed invention being already known. This bit, as shown in the highlighted part of claim 1 above, was defined purely in functional terms,  i.e. without actually defining how the capacitance sensors were kept vertically aligned. 

The examiner objected that the way the invention was claimed was unclear because it was defined by a result to be achieved and there was only one way the description showed how this would be done, which was by way of a pantographic mechanism (basically two hinged parallel bars). The claimed invention, in the examiner's view, was therefore not enabled across its whole scope (Biogen insufficiency, referring also to Novartis). The applicant's representative argued against this but didn't  manage to win the examiner over, resulting in the case coming before a hearing officer. 

The applicant's representative then argued before the hearing officer that there were other mechanisms discussed in the patent application, referring to the use of accelerometers, counterweights and pivots that could be used to keep the sensor elements vertical. While these were not actually disclosed in the application itself, the representative showed how such alternative mechanisms could work, referring to other patents and prior art documents. This appeared to persuade the hearing officer, who found that, while the specification defined only a single embodiment, the skilled person would be aware of various ways of implementing a mechanism to do the same thing. The skilled person would therefore be able to perform the invention over the whole scope of the claim without undue burden or effort, using their common general knowledge. The claims did not therefore need to be restricted to only the use of a pantographic mechanism. 

The lesson from this appears to be that, at least before the UK IPO, it is possible to impart common general knowledge to the skilled person by referencing material outside of the patent application itself. This does, however, appear to be a risky move because the more the skilled person is deemed to know, the less likely the claimed invention will be considered to be inventive. Indeed, the application has now been remitted to the examiner to consider the question of inventive step. Perhaps the applicant will manage to carefully tread the line between sufficiency on the one side and inventive step on the other but it looks to me like it could now go either way on inventive step.

Free beer and covert viewing

When an invention is defined in a claim in terms of a result to be achieved, it is often termed a 'free beer' claim, in the sense that the invention would be a good thing but the claim does not define how it is actually achieved.  When the patent specification as a whole does describe at least one way of achieving the result, the problem is one of a lack of clarity, rather than sufficiency, and can be resolved by amending the claims so that they define something the applicant has contributed to the art rather than a mere wish list of features.  At the European patent office, any free beer is typically objected to (even during Oktoberfest), and examiners will tend to require more technical features to be imported.  At the UK patent office, however, at least small amounts of free beer are more typically allowable, usually as part of a functional statement at the end of a claim, although in some cases more extensive functional language can be allowed.  Too much, however, and a UK examiner will object on grounds of lack of clarity. This was the case for application GB0904563.4 (previously published as WO 2008/035107), which has led to to the recent decision BL O/243/11, the applicant being The Secretary of State for Defence. Claim 1 of the application as-published read as follows:

1. A lens arrangement, suitable for looking through pinholes comprising a converging eyepiece type lens apparatus used without a conventional objective lens and arranged such that the lens arrangement projects a "virtual" aperture to a point in object space beyond a first end of the lens arrangement, said first end being the end of the lens arrangement closest to the subject being viewed, such that the virtual aperture limits the pencil of rays passing into the lens arrangement, wherein the lens arrangement contains no integral physical lens stop.

There are a number of obvious problems with this claim, one of which is clarity.  Following rounds of correspondence with the examiner, the claim was amended to read:

1. A lens arrangement, adapted for looking through a remote pinhole comprising a plurality of lens elements designed and configured to operate without the presence of an integral physical lens stop, such that in use the lens arrangement defines a “virtual aperture” in a pre-determined plane in object space remote from a first end of the lens arrangement, said first end being the end of the lens arrangement closest to the subject being viewed, wherein the virtual aperture acts as a remote entrance pupil in object space beyond the first end of the lens arrangement and defines a pencil of rays that passes through the lens arrangement.

The examiner considered that, even after amendment, there was too much free beer in the claims. He maintained objections that the claimed invention was unclear and was not supported by the description because the claims defined the invention in terms of the result to be achieved (i.e. a stopless lens) rather than the technical features of the lens arrangement that achieved the result, and the embodiments described did not support such a broad claim. The applicant did not manage to overcome the objections, and the matter went before a hearing officer at the IPO.

Before the hearing officer the applicant argued that, following the decision in No-Fume v Frank Pitchford & Co. Ltd. 52 RPC 231, there were many ways the invention could be implemented and the claims should not need to be limited to only one set of specific parameters. According to the applicant, conventional thinking was that a physical lens stop would be required. The lens arrangement of the invention made this redundant through the creation of a virtual aperture in the object space of the arrangement. The hearing officer accepted that the meaning of the term "virtual aperture" was sufficiently clear, but then went on to point out that the application outlined the features of the invention as being equivalent to using a conventional converging telescope eyepiece in reverse (as for example in the above figure).

As a result, the apparatus claims did not define the invention sufficiently to avoid reading directly on to an already known telescope eyepiece. The fact that the claims indicated that the lens arrangement was adapted for looking through a remote pinhole only specified how the lens arrangement could be used in practice, but did not distinguish the arrangement over a conventional telescope eyepiece. Specifying that the arrangement was designed and configured to provide the desired effect would, following Kirin-Amgen, only be allowable if the product itself was novel and inventive. The claimed invention did not therefore meet the requirements of section 14(5)(a) and (b) in that it did not define the invention and was not clear.

Although the claims in the form discussed were not allowable, the hearing officer allowed the applicant another opportunity to submit further amendments by extending the compliance period. As of today, it looks (thanks to the IPO's Ipsum file inspection service) like the application is still not quite finished.

As far as I can see, the lesson to be learned is to be careful with relying on functional definitions unless you have plenty of backup definitions that are more grounded in technical features of the invention.  It is probably not enough to have a myriad differently defined specific embodiments unless you have some overarching technical definitions to tie at least some of them together because the only option you might end up with could be a single narrow one. It is easy with hindsight to see this being a problem; the clever trick is to spot it in advance.