Mr Justice Arnold held that Vax Ltd had not infringed a UK registered design owned by Dyson Ltd in relation to the latter’s Dual Cyclone vacuum cleaner by importing and marketing the Mach Zen C-91 MZ vacuum cleaner. Although there were some similarities between the designs, there were also some significant differences, making the overall impression produced by the two designs different.


The informed user was understood to be a knowledgeable user of domestic vacuum cleaners. The correct date for carrying out the comparison was the date of the registered design. Further, the relevant design corpus was that which existed at that date.

Dyson’s novelty statement was as follows: “The features of the design for which novelty is claimed reside in the shape and configuration applied to the article as shown in the representations”. Arnold J held that, whilst the novelty statement should be taken into account, it should not be read as if restricting the design only to those features specified in the statement. If it could be shown objectively that aesthetics had also been relevant to the question of design, then the feature could not be said to have been dictated solely by its technological function.

Arnold J agreed with Vax, which submitted that design freedom may be constrained by various factors: 1) the technical function of the product, 2) the need to incorporate features common to such products, and/or 3) economic considerations (e.g., the need for an item to be inexpensive). The degree of freedom of the designer must also be judged by reference to the technical specification of the product being designed. In addition, a registered design should receive a broader scope of protection where the designer had a greater degree of freedom (as Dyson had here) and a narrower scope where the designer had a lesser degree of freedom.

Arnold J considered each of the nine similarities identified by Dyson, keeping the overall impression in mind. In most of the cases, he accepted that the degree of freedom of the designer of the Mach Zen had been restricted by technical considerations, thus resulting in an inevitable, but insignificant, similarity, thereby making minor differences more likely to make the overall impression different. Arnold J decided, therefore, that, whilst there were certain similarities between the designs, the informed user would not consider these to be particularly significant and would also notice the many differences between the designs.

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