Factual and Procedural Background
This appeal concerns the question of whether the exclusion from patentability of a program for a computer "as such" under section 1(2) of the Patents Act 1977 applies to artificial neural networks (ANNs), which underpin modern machine learning and artificial intelligence systems. The patent application, filed by Company A, relates to a system and method for providing media file recommendations based on semantic similarity derived from an ANN.
The patent application was initially rejected by the Hearing Officer on the grounds of section 1(2). On appeal, the High Court judge allowed the appeal, holding that no computer program was involved in the hardware-implemented ANN and thus the exclusion did not apply. The judge also held that even if the exclusion applied, the subject matter was not excluded. The Comptroller (Appellant) was granted leave to appeal to this court.
Legal Issues Presented
- Whether the exclusion from patentability of a program for a computer "as such" under section 1(2) of the Patents Act 1977 applies to artificial neural networks.
- If the exclusion applies, how it applies to the specific patent application concerning a system and method for media file recommendations using an ANN.
- Whether the High Court judge erred in his interpretation and application of the exclusion and related legal principles.
- Whether the claimed invention involves a substantive technical contribution sufficient to avoid exclusion.
- Whether the mathematical method exclusion under section 1(2) should apply.
Arguments of the Parties
Appellant's Arguments
- The Comptroller argued that ANNs are computers and that the set of weights and biases configuring an ANN constitutes a computer program.
- It was submitted that the weights and biases instruct the ANN how to process information and thus fall within the exclusion of a program for a computer "as such".
- The Appellant contended that there is no relevant distinction between hardware and software ANNs for the purpose of the exclusion.
- The Comptroller challenged the High Court’s acceptance of a concession that a hardware ANN is a computer without a program.
- The Appellant maintained that the mathematical method exclusion should be considered if the computer program exclusion does not apply.
Respondent's Arguments
- The Respondent (Company A) argued that an ANN is not a computer program because it does not consist of a series of human-defined logical instructions.
- They submitted that the weights and biases are not instructions but structural parameters learned through training, independent of human programming.
- The Respondent emphasized that the ANN addresses problems intractable to conventional programming and thus cannot be equated to a traditional computer program.
- It was contended that the training stage involves programming, but this is a subsidiary aspect not claimed in the patent.
- The Respondent argued that the semantic similarity of recommended files is subjective and cognitive, not technical, and therefore outside patentable subject matter.
Table of Precedents Cited
| Precedent |
Rule or Principle Cited For |
Application by the Court |
| Aerotel Ltd v Telco Holdings Ltd [2007] RPC 7 |
Four-step approach to determine patentability exclusions under s1(2) |
Used as the primary framework for analysing whether the invention falls within excluded subject matter and whether it involves a technical contribution. |
| AT&T Knowledge Ventures v Comptroller [2009] EWHC 343 (Pat) |
Five signposts for assessing whether a computer program makes a technical contribution |
Referenced to assess technical contribution and to guide the analysis of the invention's patentability. |
| Re Halliburton Energy Services [2011] EWHC 2508 (Pat) |
Technical contribution requirement in computer implemented inventions |
Supported the principle that the contribution must be technical in nature to be patentable. |
| HTC v Apple [2013] EWCA Civ 451 |
Endorsement of five signposts and approach to better computer cases |
Reinforced the approach to assessing technical contribution in computer-related inventions. |
| Protecting Kids the World Over [2011] EWHC 2720 (Pat) |
Technical effect in monitoring electronic communications |
Distinguished from the present case; the Hearing Officer rejected analogy due to subjective nature of recommendation here. |
| Gemstar v Virgin Media [2009] EWHC 3068 (Ch) |
Patentability of computer implemented inventions involving data processing |
Rejected as an analogy by the Hearing Officer due to differences in technical effect. |
| Gale's Application [1991] RPC 305 |
Definition of a computer program as a sequence of instructions |
Supported the court’s definition of a computer program as a set of instructions causing a computer to perform a task. |
| News Corp UK & Ireland Ltd v HMRC [2023] UKSC 7 |
Doctrine of "always speaking" in statutory interpretation |
Referenced to explain that the meaning of statutory terms remains constant although the scope of covered subject matter may evolve. |
| Koch v Sterzel (T26/86) |
Patentability of computer-implemented methods controlling physical devices |
Example of a patentable computer-implemented invention illustrating that ANNs would be no different. |
| T 702/20 Mitsubishi/Sparsely connected neural network (EPO Technical Board of Appeal) |
Approach to patentability of neural network inventions and computer programs |
Confirmed that ANNs relate to computer programs and mathematical methods and the exclusion applies accordingly. |
| Yahoo T 0306/10 (EPO Technical Board of Appeal) |
Technical effect in recommendation systems based on subjective quality |
Supported the conclusion that subjective assessment of recommendation quality does not amount to a technical effect. |
Court's Reasoning and Analysis
The court began by analysing the nature of artificial neural networks (ANNs) and their implementation, distinguishing hardware and software ANNs but concluding that both are computers for the purpose of patent law because they are machines that process information.
Drawing on dictionary definitions and established case law, the court defined a "computer program" as a set of instructions that cause a computer to process information in a particular way. The court rejected arguments that a computer program must be written by a human or must follow a logical 'if-then' structure, holding that how the instructions are created or their form is irrelevant.
The court held that the weights and biases of an ANN, which determine how the ANN processes inputs to produce outputs, constitute a computer program. This applies equally to hardware and software ANNs. Therefore, the exclusion of computer programs "as such" under section 1(2) of the Patents Act 1977 is engaged in this case.
Turning to the patentability of the invention, the court applied the Aerotel four-step test. The contribution was agreed to be an ANN-based system providing improved file recommendations through training that aligns physical properties of files with semantic similarity.
The court agreed with the Hearing Officer that except for the step of sending the recommended file to the user, the contribution consists solely of a computer program. The act of sending a file is a concrete task but the value of the recommendation is based on semantic qualities, which are subjective and cognitive rather than technical.
The court rejected the High Court judge’s view that the system produces a technical effect because it applies technical criteria in its analysis and selection. The court found that this reasoning improperly imported the technical nature of the computer into the analysis of the contribution.
Considering the signposts from AT&T Knowledge Ventures and relevant case law, the court found no technical contribution sufficient to avoid exclusion. The semantic similarity and resulting recommendations are non-technical and thus fall within the exclusion.
The court noted that the mathematical method exclusion was not necessary to decide but indicated it would likely apply if the computer program exclusion did not.
Holding and Implications
The court ALLOWED THE APPEAL on the ground that the patent application is excluded from patentability under section 1(2) of the Patents Act 1977 as a computer program "as such".
The direct effect is that the patent application by Company A for the ANN-based media recommendation system is rejected. The court's decision clarifies that the weights and biases of an ANN constitute a computer program for the purposes of patent law, and that semantic or subjective qualities derived from such systems do not constitute a technical contribution sufficient to overcome the exclusion.
No new precedent was set beyond affirming and applying existing principles in the context of ANNs. The decision confirms that ANN-implemented inventions are treated consistently with other computer-implemented inventions under UK patent law.