Chiaro Technology Limited v Mayborn (UK) Limited

In assessing infringement of a registered design, the court must compare the overall impressions produced on the informed user, while excluding features whose appearance is solely dictated by technical function. The multiplicity of forms theory does not prevent a feature from being functional merely because alternative designs could perform the same function.

Technical function is assessed objectively. The designer’s subjective intentions are not relevant, although patents may provide objective, and sometimes strong, evidence of functionality. Design freedom is assessed by starting with the registered design and identifying functional, common-product and economic constraints. The design corpus remains relevant evidence, but a departure from it is not conclusive. Differences may produce a different overall impression where design freedom is constrained.

Chiaro Technology Limited owned three registered designs for an integrated, wearable breast pump: the pump as a whole, its front housing and its milk collection vessel. It alleged that Mayborn (UK) Limited infringed them by selling the Tommee Tippee Made for Me Wearable Breast Pump.

The issues included the proper sector and informed user, the effect of technical function under section 1C(1) of the Registered Designs Act 1949, the significance of patents and the design corpus, the designer’s degree of freedom, and whether the accused product produced a different overall impression under section 7.

1. Technical function. Features are excluded under section 1C(1) of the Registered Designs Act 1949 where their appearance is solely dictated by technical function. The inquiry is objective. The multiplicity of forms theory is unavailable: the existence of alternative forms does not prevent a feature from being solely functional.

2. The designer’s subjective intentions are not relevant. Patents may nevertheless be considered as objective evidence of functionality, including patents owned by the registered design proprietor. They are not conclusive statements of design motivation.

3. The outward tear-drop or ovoid shape of the pump and milk collection vessel, the concave breast shield, the flat bottom of the vessel and its transparency were, to the extent identified, technically functional. Those features were excluded from the comparison under section 1C(1).

4. Design freedom. Functional constraints must be identified by starting with the registered design. The design corpus is relevant as evidence of available design approaches and freedom, but departure from the corpus is only an indication and is not an absolute rule. Functional and other constraints can make differences more significant.

5. Infringement. The relevant sector was electrical breast pumps, with a narrower corpus of wearable electrical pumps. The informed user was a nursing mother or wet nurse, attentive to the appearance and handling of the product. Applying section 7, the differences in housing contours, scallops, recesses, buttons, ports, rear structures and vessel configuration produced a different overall impression for each of the three designs.

6. The claim for infringement was dismissed. The MFM product did not infringe any of the registered designs.