It all seemed normal business for Pharrell Williams as he arrived at Berlin Fashion week to launch his eco-friendly Bionic Yarn range.

No word about his recent lawsuit against fellow rapper will.i.am.

On Monday (July 1) the music producer had asked a U.S. court to rule that he has not violated any trademarks owned by the Black Eyed Peas star.

The lawsuit said that will.i.am, real name William Adams, has repeatedly sent letters to Williams demanding he stop using versions of the phrase "I AM" on his website iamother.com.

However William's company, I Am Other Entertainment, claims it hasn't committed any violations, highlighting the differences in spelling.

William's website hasn't used any periods between the "i" and the "am." Those owned by will.i.am do.

According to Brad Rose, a counsel for Williams, the lawsuit is asking the court to declare the phrase "I Am Other" does not "infringe, dilute or unfairly compete" with will.i.am.

In Berlin, Wil