Patent Eligibility of Electronic Systems and Circuits

Over the past few years we’ve seen an increase in the patenting of electronic systems and circuits. Factors driving this increase include:

• emerging technologies such as wearable, implantable and IoT devices, for which minimising power consumption is key;
• electrification of vehicles and other traditionally more mechanical systems; and
• the rise of renewable electricity sources.

In this series of articles, we will look at some of the common issues that arise when patenting electronic systems and circuits at the European Patent Office (EPO) and the UK Intellectual Property Office (UKIPO), and how we can mitigate these issues. Note that although we have approached this topic from a European/UK patent perspective, many of the issues raised arise in other jurisdictions and our suggestions may therefore also be useful in those other jurisdictions.

In contrast to many other high-tech areas (e.g. software, artificial intelligence, blockchain) where questions of patent eligibility are commonplace, in the field of electronics it is rare to see an objection that the invention for which a patent is sought is excluded from patent protection. This is because electronic systems and circuits are typically physical systems that produce well-defined technical effects on real-world entities.

When we looked at the decisions of the EPO’s Technical Boards of Appeal for cases relating to applications in the H03 International Patent Classification (“Basic Electronic Circuitry”), we found a total of 426 published decisions, of which there was only a single case in which patent eligibility was an issue.

The case in question, T212/94, was a successful appeal against a decision of the Examining Division to refuse a patent application titled “Resisting the effects of channel noise in digital transmission of information”. The application related to a method for transmitting information in a communication system, in which binary index codes are assigned to codewords representing vector quantized information for transmission in accordance with a codebook.

In this case the question of patent eligibility did not even arise during examination. Instead, the Examining Division refused the application on the grounds of lack of clarity and lack of inventive step.

However, on appeal the Technical Board of Appeal argued that the expression “assigning binary index code signals to codewords representing vector quantized information” used in the independent claims merely defined a mathematical function mapping vectors to binary numbers. The Board argued that the claimed invention therefore related to a mathematical method as such, and was thus excluded from patentability under Article 52(2)(a) of the European Patent Convention.

In response, the applicant amended the independent claims of the application to specify that the code words represent audio or image information, and to include a reference to the function of the codebook. The offending expression was amended to read: “assigning binary index code signal to codewords representing vector quantized audio information or vector quantized image information for transmission in a communication system in accordance with a codebook”.

The Board found that, although the idea underlying the invention could be considered to be a mathematical method, the amended claims were directed to the processing of audio or image signals, which are themselves physical entities. Accordingly, the Board held that the claimed invention did not relate to a mathematical method as such, and thus was not excluded from patentability.

A key point here is that by defining in the claim that the information being processed was audio and image information, the applicant was able to argue successfully that the claimed invention did not relate purely to a mathematical method, but was instead directed to operations on physical entities, and so was not excluded from patentability.

Most inventions in the area of electronic systems and circuits perform some technical process (e.g. filtering, noise reduction, image enhancement, amplification) on a real-world entity (e.g. an electrical signal such as a video, audio or image signal, a sensor output signal or the like) to achieve a technical effect. It is therefore unlikely that objections that the invention is excluded from patentability will be raised at the EPO. Even if such an objection is raised, it can usually be overcome by careful amendment of the claims to more clearly reflect the technical effect of the invention on a real-world entity (provided that the specification supports such an amendment).

Our Electronics Systems & Circuits team are always on hand to guide you through the pitfalls of patenting in this area. Feel free to reach out to us with any questions you might have.