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Symbian Ltd v Comptroller General of Patents: UK Court Of Appeal Extends The Patentability Of Computer Programs

Symbian Ltd v Comptroller General of Patents: UK Court Of Appeal Extends The Patentability Of Computer Programs


The Case


The Court of Appeal judgment in Symbian Ltd v Comptroller General of Patents, published 8 October 2008, dismissed UK-IPO's appeal against the decision of Mr Justice Patten in the High Court, in which he overturned the UK-IPO's decision to refuse an application by Symbian, on the ground that it consisted solely of a computer program.


The current patentability test in the UK is the so-called "Aerotel/Macrossan test". It is a four stage test involving:

1.      Properly construing the claim;

2.      Identifying the actual contribution;

3.      Asking whether it falls solely within the excluded subject matter;

4.      Checking whether the actual or alleged contribution is actually technical in nature.


Symbian's patent application describes how in a computer a library of functions (DLL), which can be called on by multiple application programs running on the computer, is accessed. In particular, it provides a way of indexing these library functions to ensure the computer will continue to operate reliably after changes are made to the library. The claims were directed to a method, a device implementing that method and software arranged to implement the method. A key feature of Symbian’s invention is that it is a computer program which operates within a computer to improve the internal functioning of the computer.


The UK-IPO refused the application on the grounds that the invention related to a computer program “as such” and therefore, according to its interpretation of the Aerotel/Macrossan test, must be excluded from patentability.


The UK-IPO’s decision was overturned in the High Court appeal, in which Mr Justice Patten observed that the UK-IPO's decision in this case illustrated the divide which exists between the UK-IPO and the European Patent Office about how the patentability of inventions involving computer programs is assessed. In concluding he stated that “the end result of the invention (as claimed) is that it does solve a technical problem lying within the computer."


The UK-IPO appealed against the High Court decision. In dismissing the appeal, the Court of Appeal summarised the current approach to assessing patentability as follows:


“…identify "the contribution" in order to decide whether that contribution is solely "the excluded subject-matter itself", while emphasising that the contribution must be "technical".”


When applying the Aerotel/Macrossan test, the Court held that the invention as claimed was not solely excluded subject matter “because it has the knock-on effect of the computer working better as a matter of practical reality”, and that the invention does solve a technical problem lying with the computer itself.



So What Does This Mean?


In summary, computer programs, or to be more precise - computer implemented inventions (CII’s), are patentable in the UK, providing the claimed invention makes a technical contribution to the art. This has been confirmed as including computer programs that operate solely to improve or modify the internal functioning of a computer.


Practitioners should ensure that when drafting patent applications for the UK, or the EPO designating the UK, concerning computer implemented inventions they describe in detail the technical contribution the computer program makes and the mechanism by which that technical contribution is achieved.  This is essential for supporting allowable claims to computer implemented inventions, in particular when the invention works solely on the internal functioning of the computer


This decision brings the assessment of computer implemented inventions in the UK closer to that of the EPO and importantly emphasises the need to clearly describe and claim the technical features of the invention in patent applications.