Back on 1994, Dyson Ldt filed a U.K. registered design application over one of its line of vacuum cleaners. Leaning on that, the company brought an action to the British High Court of Justice (Chancery Division) claiming its registered design was infringed by Vax’s Mach Zen C-91 MZ vacuum cleaner. On the July 29, 2010, the Hon Mr. Justice Arnold dismissed the claim holding that Dyson’s DC02 model was not infringed by the Vax’s Mach Zen C-91 MZ.
Dyson appealed the High Court of Justice’s judgment.
Indeed, Dyson contended that their DC02 model was a major departure from previous art and consequently deserved a wide degree of protection. Nonetheless, the Court of Appeal considered that several technical reasons justified the design. Therefore, the Court concluded that the degree of design freedom was affected because each of the similarities between the two vacuums had technical significances.
Besides, it appears to the judges that the informed user looking at the two designs would notice the difference. According to previous case law, the informed user needs to be distinguished from the average consumer of the trademark law. Indeed, the informed user is a person who uses the product in which the design is incorporated and without being an expert, knows the various designs which exist in the sector concerned.
In this case, given this character’s relatively high degree of attention, the overall impression produced on the informed user by the registered design is “smooth, curving and elegant” whereas the overall impression produced by the other is “rugged, angular and industrial, even somewhat brutal”. In a similar way of the judgment provided by the High Court of Justice, the Court of Appeal found that the overall impressions produced on the informed user are different and consequently that the two designs were different.
Thus, Dyson design infringement claim has been dismissed by the Court of Appeal (Civil Division). The famous vacuum cleaner manufacturer should have taken more seriously the importance of the overall impression on the informed user.
 Dyson Ltd v. Vax Ltd  EWHC 1923 (Pat) : “ Even on the basis that the Registered Design is entitled to a fairly broad scope of protection because of the differences between the Registered Design and the existing design corpus and because of the degree of freedom of the designer, in my judgment the overall impressions produced by the two designs are different”
 General Court of the European Union, Case T-153/08 Shenzhen Taiden v. Office for Harmonisation in the Internal Market  ECR II-000 (paragraph )
 Dyson Ltd v. Vax Ltd  EWCA Civ 1206