Canon Kabushiki Kaisha v Green Cartridge Co (Hong Kong) Ltd[1] is a 1997 decision of the Judicial Committee of the Privy Council (1) re-affirming the principle of UK copyright law that the copying of functional three-dimensional objects is an infringing reproduction of the drawings of the objects, and (2) limiting the doctrine of non-derogation from grants as to chattels to "the case in which the unfairness to the customer and the anticompetitive nature of the monopoly is as plain and obvious as it appeared to the House of Lords in the British Leyland case."
He concluded, "It is of course a strong thing (not to say constitutionally questionable) for a judicially-declared head of public policy to be treated as overriding or qualifying an express statutory right."
...They will therefore humbly advise Her Majesty that the appeal should be allowed....In Mars U.K. Ltd. v. Teknowledge Ltd.,[3] the High Court of Justice, Chancery Division, considered the non-derogation doctrine in the wake of Green Cartridge.
Mr. Justice Jacob interpreted Green Cartridge as holding that the British Leyland “spare parts exception applied only where it was plain and obvious that the replacement was analogous to a repair which an ordinary purchaser of an article would assume he could do for himself without infringing the manufacturer’s rights, or that the exercise of monopoly power by means of copyright would be against consumers’ interests."
The court held that the circumstances of the Mars case—altering a coin changer to operate for changes made in UK coinage—did not warrant invocation of the non-derogation doctrine.