UK Court of Appeal overturns High Court ruling on patents for AI
In a judgment1 that deals a significant blow to the UK AI industry, the UK Court of Appeal has held that AI inventions comprising artificial neural networks (ANNs) fall within the exclusion from patentability for “computer programs” in the UK Patents Act. ANNs are therefore not patentable in the UK, unless they escape the exclusion by making a sufficient technical contribution outside of the ANN. In its judgment, the Court of Appeal overturned a High Court decision from November 2023 that was considered to be favourable to AI-inventors, and has brought the UK back in line with the more restrictive approach taken by the European Patent Office (EPO).
Background
ANNs are the backbone of the machine learning systems on which artificial intelligence systems are based. ANNs are hardware or software systems that can be trained to process inputs in a certain way and learn from that training, resulting in weightings or ‘weights’ within the system. The trained ANN can then process new inputs using those weights to give an output or result. In this case, Emotional Perception AI (EPAI) sought a patent for an ANN which has been trained to provide media file recommendations based on semantic or text inputs provided by a user. For example, a user could request songs that are ‘happy’ or ‘relaxing’, and the trained ANN would provide a corresponding song recommendation.
The UK Intellectual Property Office (UKIPO) initially rejected EPAI’s patent application on the basis that the invention was a computer program with no technical effect beyond that program, and was therefore not patentable under Section 1(2)(c) Patents Act 1977, which excludes “a program for a computer…as such” from the scope of patentable subject matter. However, in November 2023, the UK High Court overturned the UKIPO’s decision, holding that an ANN is not a computer program and, even if it were, EPAI’s ANN had sufficient technical effect to escape the exclusion. This decision was surprising, as it differed from the approach taken by the EPO and in various other jurisdictions, making the UK a favourable jurisdiction for patent applications relating to ANNs.
The UKIPO appealed to the Court of Appeal.
The Court of Appeal’s decision
The Court of Appeal considered two key questions:
- Is an ANN a “computer program”?
The Court of Appeal held that a computer is a machine which processes information, and a “computer program” is a set of instructions for a computer to do something. Those two definitions work together, so that a computer is a “machine which does something, and that thing it does is to process information in a particular way. The program is the set of instructions which cause the machine to process the information in that particular way, rather than in another way.”
The Court then held that an ANN, whether implemented in hardware or software, is clearly a computer. EPAI had argued that to be a computer program, the relevant instructions must take the form of a logical series of “if-then” statements defined by a human programmer. The ANN, by contrast, makes decisions based on ‘weights’ it has learnt itself. The Court rejected this argument, finding that the weights cause the machine to process information in a particular way and therefore the weights are a computer program. The fact that they do not take the form of a logical series of “if-then” type statements is irrelevant to that categorisation. Moreover, there is no justification for drawing a distinction in law between instructions created by a computer and those created by a human.
ANNs may therefore fall within the exclusion for computer programs in section 1(2) Patents Act 1977.
- Does the claimed invention nevertheless make a sufficient technical contribution to be patentable?
The Court of Appeal noted that the fact that the exclusion is engaged simply means that ANN-implemented inventions are in no better and no worse a position than other computer-implemented inventions. It is still possible for ANNs (and other computer-implemented inventions) to be patentable if they make a sufficient technical contribution beyond the computer program or by improving the functioning of the computer.
Here, however, there was no technical contribution. Put simply, EPAI’s ANN provides file recommendations based on the semantic qualities of the files. This is a matter of aesthetics, with the recommendations being subjective and cognitive in nature. They are not technical and do not turn this into a system which produces a technical effect outside the excluded subject matter.
On that basis, the Court of Appeal allowed the appeal and upheld the UKIPO Hearing Officer’s decision that EPAI’s ANN was excluded from patentability. The Court of Appeal added that if the weights within an ANN were not a computer program, it is hard to see why they would not be excluded from patentability (in the absence of a technical contribution) as a mathematical method – another category of inventions excluded under the Patents Act 1977.
Comment
This important decision returns the UK’s approach to patentability of AI inventions to where it was prior to last year’s High Court decision, i.e. AI inventions will typically be within the exclusion for computer programs “as such”, save where they offer a sufficient technical contribution beyond the computer program itself. Consequently, the UKIPO will have to re-amend its guidelines for examining patent applications relating to AI which it had updated following the High Court’s decision last year. Those guidelines are currently temporarily suspended while the UKIPO considers the Court of Appeal’s recent decision.
While the overturned High Court decision was generally seen to make the UK an AI-friendly jurisdiction, the Court of Appeal’s approach is more in line with the approach taken by the EPO (e.g. in T702/20 Mitsubishi/Sparsely connected neural network, in which the EPO’s Board of Appeal applied the same approach to ANNs as it applies to any other computer-implemented invention) and in many other jurisdictions.
