The Federal Patent Court of Germany has invalidated Microsoft's FAT patent which has been extensively used by the company against Android device manufacturers to gather royalties and impose sales bans over the last few years.

Bundespatentgericht (Federal Patent Court of Germany, BPatG) held an invalidation trial on Thursday at the end of which it was declared by Judge Vivian Sredl that the patent is completely invalid and does not satisfy the technicity requirement of European patent law.

FOSS Patents posted that:

"..common name space for long and short filenames" is invalid in its entirety (including Microsoft's proposed amendments) because the court found that all of the elements distinguishing the patented invention from the prior art (which includes a Linus Torvalds post to a mailing list) did not satisfy the technicity requirement under European patent law.

Microsoft is expected to appeal the decision as this patent has been one of the most important factors in imposing sales ban on Motorola devices in Germany and has helped many more injunctions till now.

In the past the same patent has been invalidated and reinstated, which was used against Linux at that time. Since Android uses the Linux kernel, Microsoft has used the patent to form litigation against the device manufacturers to gain sales bans in Germany and the United States.

The outcome of the ruling will affect Microsoft in all member states of the European Union as uniform laws exist across the EU.

Source: FOSS Patents via Forbes