The IPO has published an important new note providing guidance on the patentability of computer programs following the Symbian judgment.
Patents Act 1977: Patentability of computer programs
1. This notice provides further guidance on how patent examiners will assess the patentability of inventions with particular emphasis on the exclusion of computer programs as such. It follows the recent judgment of the Court of Appeal in the case of Symbian Ltd's Application  EWCA Civ 1066 ("Symbian"). It should be read with the Practice Notices dated 2 November 2006 and 7 February 2008 on patentable subject matter.
2. The patent application in Symbian is about how a library of functions (a "Dynamic Link Library"), useable by multiple application programs running on a computer, is accessed. It provides a way of indexing the library functions so that the computer will continue to work reliably even after making changes to the library. When the Court of Appeal considered its conclusion in accordance with the Aerotel/Macrossan (236Kb) test it took the view that the contribution made by Symbian was not a computer program "as such" because "it has the knock-on effect of the computer working better as a matter of practical reality".
The test for deciding whether a computer-implemented invention is patentable
3. The Court of Appeal by and large approached the question of whether Symbian’s invention was excluded as a program for a computer as such by looking for a "technical contribution". In doing so it confirmed a line of UK case law dating back to the EPO Board of Appeal decision in Vicom . The Court also confirmed that the Aerotel/Macrossan test is intended to be in substance the same test as that relied on in the prior UK case law. Since both tests are legitimate for determining excluded matter, examiners will apply the structured approach of Aerotel/Macrossan to address the fundamental question whether a claim falls solely within the excluded matter. The Office considers that as a matter of practice this will achieve outcomes consistent with the Court of Appeal judgment in Symbian more reliably.
Identifying whether a contribution is solely a computer program
4. The Symbian judgment (especially paragraphs 54-56) provides an insight into what constitutes a technical contribution; in other words, a contribution that is more than solely a computer program. An important factor is what the program does as a matter of practical reality.
5. The Intellectual Property Office has previously recognised that an invention which either solves a technical problem external to the computer or solves "a technical problem within the computer" is not excluded. What Symbian has now shown is that improving the operation of a computer by solving a problem arising from the way the computer was programmed - for example, a tendency to crash due to conflicting library program calls - can also be regarded as solving "a technical problem within the computer" if it leads to a more reliable computer. Thus, a program that results in a computer running faster or more reliably may be considered to provide a technical contribution even if the invention solely addresses a problem in the programming.
6. It remains the case that whilst an invention involving a computer is undoubtedly "technical", in law the mere presence of conventional computing hardware does not of itself mean an invention makes a technical contribution and so avoids the computer program exclusion. This is in contrast to the practice of the European Patent Office, which the Court of Appeal rejected in Symbian.
Computer-implemented inventions and other exclusions from patentability
7. Symbian also indicates (paragraph 27) that one effect of the computer program exclusion is to prevent other excluded material becoming patentable merely by use of a computer in its implementation. Thus, a business method, mental act, mathematical method or presentation of information implemented on a conventional computer system or network would still be excluded.
8. Paragraph 13 of the previous Practice Notice dated 2 November 2006 noted the different judicial comments regarding computerisation of acts which would otherwise have been done mentally. In future examiners will object to the computerisation of what would be a pure mental act if done without the aid of a computer as both a mental act and a computer program as such. A similar logic applies to the other exclusions.