Inventive step – assessment on ‘balance of probabilities’ – relevant law applying to application filed on 26 February 2003
A patent hearing officer has upheld an examiner’s finding that claims directed to a ‘mushroom stud and keyhole’ arrangement for assembling a lighting unit (‘luminaire’) are obvious and lacking inventive step, despite provision by the applicant of evidence arguably supporting a contrary view.
Interestingly, however, examination of the application seems to have proceeded on the basis that it would not be permissible to combine the teachings of two prior art documents in order to establish obviousness of the claimed invention. This was indeed the case under the Australian law of inventive step prior to 1 April 2002. But we are not sure that it was the appropriate law to apply the case of this application.
Australian patent application no. 2008229901 in the name of Paul Andrew Cronk is for ‘A Luminaire Reflector Locating Arrangement’, and derives (as a divisional) from an earlier application having an effective filing date of 26 February 2003.
We are inclined to question a finding of a lack of inventive step which is not supported by the only actual evidence presented at the hearing. But unless we are missing something here, the bigger question is why the examiner, and the hearing officer, apparently failed to apply the post-2002 law in this case. This is especially perplexing, when the amended law substantially favours the Patent Office position that the claims are not inventive!
It is possible that we will ultimately get a definitive answer to both questions, because on 11 April 2012, Cronk filed a Notice of Appeal against the decision in the Federal Court of Australia (no. NSD532/2012).
THE ALLEGED INVENTIONThe patent specification relates to lighting arrangements, and more particularly to assemblies in which curved reflectors are provided behind a fluorescent tube, which are adjustable in order to control the focus of light onto items positioned below.
The evidence suggests that such luminaires are commonly employed in hydroponic nurseries for directing light onto plants growing beneath the lamps.
Prior art luminaires were assembled using nuts and bolts, or similar fasteners, which were evidently cumbersome and time-consuming to fix in place. The claimed invention provides a simpler method of assembly, based upon a ‘mushroom stud and keyhole’ arrangement.
Specifically, claim 1 defines the invention as follows:
1. A locating mechanism for a pair of reflector sheets from which the reflector of a doubly arched luminaire is assembled, said mechanism comprising at least one mushroom-shaped stud on one of said sheets and a corresponding keyhole shaped aperture on the other of said sheets, said stud comprising a stalk and a cap and said aperture comprising a main opening and a smaller extension wherein each said stud and aperture are dimensioned so that said cap can pass through said main opening but not said extension and said stalk can be retained in said extension with a friction fit.
The features in question are clearly visible in Figure 3 of the drawings in the patent specification, reproduced below. The ‘mushroom studs’ are identified by numeral 107, and the keyhole-shaped slots by numeral 127.
The main prior art reference was an earlier patent application by the same inventor (Paul Andrew Cronk). The earlier application shows similar sheet metal components with holes for joining, but does not provide any description of the specific means used to effect the joins (see decision at ).
So the use of the ‘mushroom stud and keyhole’ arrangement was novel. The only issue raised during examination of the application was whether it was inventive.
THE TEST FOR INVENTIVE STEPUnder the pre-2002 law, it was necessary to establish that any elements of the invention missing from a single prior art document could have been derived by some obvious process from the common general knowledge (CGK) of the skilled worker in Australia. This is necessarily a matter for evidence, normally provided by someone having suitable experience within the relevant local industry. Documents or other information derived from international sources would not usually suffice for this purpose, unless corroborating evidence establishes that they are representative of the Australian situation.
One approach approved by the High Court is summarised in the decision (at ):
… any potential solution to a problem will not be obvious unless it would have been a matter of routine to try that solution, but with the significant caveat that there must be an expectation that the potential solution "might well" solve the problem. It is not necessary that success is guaranteed.
In this case, therefore, it would be necessary to establish that the use of the ‘mushroom stud and keyhole’ arrangement is one which would have presented itself routinely to an uninventive worker in the field, with the expectation that there was a good chance it would be effective.
THE EVIDENCEThe examiner identified a number of additional prior art documents (including US and Japanese patent specifications) which showed the use of mushroom studs and keyhole slots in a variety of different applications. The supposed significance of these documents is explained in the decision (at ):
The evidence produced by the examiner is a number of patent applications that show the use of keyhole slots. The examiner has not argued that any of these documents are themselves common general knowledge, and indeed such an argument could not be sustained. The examiner has advanced these documents to show that the concept of using keyhole slots and mushroom studs to join metal elements is well known.
These documents are not ‘evidence’ that would, in itself, be admissible in court. However, the Patent Office acts in the capacity of an administrative tribunal, and is not bound by the rules of evidence. Nonetheless, it is worth bearing in mind that the mere existence of documents does not, in itself, establish a number of key elements required for the proper assessment of inventive step, such as:
- whether the documents in fact contain information that was well-known to persons working in the field at the priority date of the application;
- if so, whether this information would indeed present itself as a ‘routine’ option to simplify the assembly of luminaires of the type described in the specification; and/or
- whether there was some reason the skilled person would not consider that a ‘mushroom stud and keyhole’ arrangement ‘might well’ provide an effective solution (e.g. there may be manufacturing or safety issues to consider).
- customers considered the luminaires having the ‘mushroom stud and keyhole’ arrangement to be a significant improvement over nut-and-bolt assembly, such that they were willing to wait for stock, and pay a price premium;
- the use of a ‘mushroom stud and keyhole’ arrangement for interconnection of metal sheets was unknown to a senior member of the hydroponics industry; and
- on at least one earlier occasion, another inventor had identified the problem with assembly of the luminaires, but had nonetheless failed to solve it in the manner of the claimed invention.
THE DECISIONIt is well-established that the Patent Office must apply a ‘balance of probabilities’ test when assessing inventive step (see decision at -). This requires the evidence on both sides to be weighed-up, and a decision to be made as to whether it is more likely than not that the claimed invention was – or was not – obvious.
On the face of it, the evidence in this case, on both sides, is fairly weak and of an indirect and circumstantial nature. All the patent examiner had done was to find some documents showing that ‘mushroom stud and keyhole’ arrangements had been used for various purposes over the years. The applicant, on the other hand, had established that the claimed invention was popular with customers, and had not been devised previously by an inventor looking at similar issues. This is suggestive that the invention was not obvious to people at the time, but hardly conclusive.
But at least the applicant had evidence from actual people experienced with the product in question, both of whom appeared to think the claimed arrangement was a pretty good innovation. The examiner had, perhaps, a feeling that the invention should be obvious, along with the results of a patent search specifically directed to finding documents describing use of ‘mushroom stud and keyhole’ arrangements.
In our view, the balance of probabilities in this case favours the applicant. While the evidence of inventiveness may not be strong, there is no credible evidence as to what would, or would not, have constituted ‘routine steps’ for the skilled work at the priority date. The examiner’s patent search was motivated and directed by hindsight knowledge of the claimed invention.
However, the hearing officer took a different approach. He firstly considered the documents identified by the examiner, and concluded that these established a ‘prima facie’ case of obviousness (at  and ). He then considered the evidence provided by the applicant, and asked whether, on the balance of probabilities, this evidence was sufficient to rebut the presumption of obviousness (at -). He concluded that it was not (at ).
THE ERROR IN THE APPROACH TO INVENTIVE STEPWith all due respect to the hearing officer, the approach that he took to weighing-up the evidence is clearly incorrect. Deciding on the ‘balance of probabilities’ requires a dispassionate side-by-side assessment of the competing evidence. This is not the same thing as considering whether the evidence on one side creates a prima facie case of obviousness, and then requiring the applicant to rebut this presumption on the balance of probabilities.
This case is a perfect illustration of why this approach is wrong. The evidence on both sides is inconclusive and circumstantial, however taking either side alone is sufficient to support an initial presumption in favour of either the examiner or the applicant. Once such a presumption is established, the evidence on the other side provides insufficient rebuttal, precisely because it is inconclusive.
To put it another way, if the hearing officer had looked at the applicant’s evidence first, it might be said that a prima facie case of inventiveness was established – after all, two people familiar with the product in question considered it a substantial improvement over its predecessors, while an independent inventor had failed to reach the claimed solution to the limitations of the prior art. It hardly seems likely that a few patent specifications, cherry-picked from the contents of the global databases, would be sufficient to rebut such a case, despite its circumstantial nature.
In short, a balance of probabilities cannot be evaluated if priority is given to one side or the other. The cards must be laid out on the table, and read as a whole.
WAS THERE AN OVERSIGHT IN APPLYING THE LAW?The Patents Amendment Act no. 160 of 2001 commenced on 1 April 2002.
Item 4 of Schedule 1 amended the provisions of the Patents Act 1990 relating to inventive step such that an obviousness case could be based on ‘a combination of any 2 or more pieces of prior art information, being information that the skilled person … could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood, regarded as relevant and … combined’.
In other words, the amendment expanded the scope of obviousness to include the possibility of combining information from multiple prior art documents, rather than being able to rely only upon the content of a single document in light of CGK.
Item 13 of the Schedule provided that ‘the amendments made by this Part apply in relation to .. patents for which the complete application is made on or after the day on which this Schedule commences’.
In this case, priority was claimed from a provisional application originally filed on 27 February 2002 (i.e. before 1 April 2002), however the initial complete application was not filed until 26 February 2003, i.e. after 1 April 2002.
The amended provision therefore appears to apply to the application. The examiner – and the hearing officer – could, and should, have argued that the invention could be derived by an obvious combination of the earlier Cronk application, and any one or more of the various prior publications disclosing a ‘mushroom stud and keyhole’ arrangement.
Evidence would still have been admissible on the issue of whether the skilled person could reasonably have been expected to make the combination in question, but the balance of probabilities may well have then been quite different.
CONCLUSIONIt seems a bizarre situation that the Patent Office may have applied faulty reasoning on one hand, and less favourable law on the other, and yet possibly managed to stumble upon the correct outcome!
We have some sympathy for the position of the examiner and the hearing officer in considering the claimed invention in this case to be obvious – it certainly does not appear to be one of the great technological breakthroughs of out time! However, the law is what it is, and it must be applied without fear or favour in the most objective manner possible, to all cases.
The reasoning in this case was not objective, because it arbitrarily gave precedence to the examiner’s conclusion, setting the applicant a burden of rebuttal, rather than weighing-up all of the evidence together as required for a true ‘balancing’.
And yet, at the same time, it appears that an unnecessarily restrictive earlier version of the law was applied – a law which, on the face of it, should have favoured the applicant.
If the Federal Court appeal proceeds, the final decision should make for interesting reading!