There are three aspects to proving copyright infringement.

First, the infringing work needs to be objectively similar.  It needs to look like it is a copy of the copyright work.  There needs to be a resemblance between the two.  The Court is looking for striking similarities.  Care needs to be taken in assessing objective similarity where the copyright work is not particularly original. This might be because the design of the product is commonplace or because its form is dictated by function or industry standards.

Secondly, there needs to be “a causal connection”.  Because direct evidence of actual copying is often hard to come by Courts will look to the facts which suggest that it is more likely than not that the design of the defendant’s product is derived from the copyright work or the copyright work was the starting point for the design.  The infringer does not need to have seen the actual original drawings.  The fact that the copyright owner’s product is available on the market and was accessible to the infringer can be sufficient.

Thirdly, a substantial part of the copyright work needs to have been taken.  The Court focuses on quality not quantity.  The Court will look for ‘fingerprints’ of copying.  Often the designer of the copyright work will be able to describe how there were aspects of the design that could be improved or were design ‘mistakes’ or peculiarities that were the result of trial and error and that these have been reproduced in the infringing copy.

The Court will be particularly interested in any evidence, or, the absence of evidence, of a credible independent design path by the infringer. Usually it will be fatal to any defence if the drawings that a defendant has to produce under discovery show that it started the design process with the copyright owner’s product and simply made minor changes so that the two products did not look identical.