Microsoft defeats Google over a third patent in Germany
Microsoft has scored another patent victory over Google's Motorola unit.
A German court ruled that several Motorola tablets and phones had infringed a method for apps to handle different kinds of user input.
Samsung, HTC and others pay a licence to use the technology, but Motorola had resisted.
Google now faces additional sales restrictions on its products in Germany unless it makes significant changes to its Android operating system.
It marks the third lawsuit Microsoft has won over Google in recent months in the country.
"We're pleased this decision builds on previous rulings in Germany that have already found Motorola is broadly infringing Microsoft's intellectual property," said Microsoft's deputy general counsel David Howard.
"We will continue to enforce injunctions against Motorola products in Germany and hope Motorola will join other Android device makers by taking a licence to Microsoft's patented inventions."
A statement from Google said: "We are waiting for the written decision and are evaluating our options, including an appeal."
The patent in the latest case notes that handsets are too small to "accommodate a full character keyboard" leading to a need for different ways for a user to input data.
It describes the use of on-screen letter and numeric keyboards; handwriting and drawing interfaces; and voice recognition.
It then goes on to describe a way a layer of software could sit between these input mechanisms and a device's apps. The software is used to translate the data signals into a single language that the apps can understand.
The advantage is that app developers do not need to write instructions for their products to work out how to interpret the different input mechanisms, making it easier for them to create new programs.
Unlike other claims in other intellectual property lawsuits - such as Apple's allegation that Motorola had copied its bounceback list feature - the technology in this case relates to an underlying feature of Android rather than a visual flourish.
It might therefore be harder for Google to issue a software update to work around the issue rather than to agree to pay a licence.
Microsoft now has the option of pursuing a sales ban or recall for which it must lay down a multi-million euro bond.
It would risk forfeiting the cash if it lost the case on appeal and had to compensate Google for lost sales.
However, any such move would be symbolic in nature since it has already forced Motorola products off German store shelves after winning earlier cases involving file system and text messaging patents.
The legal action has not been one-sided.
In May Google won the right to prevent Germany's stores from selling Microsoft's Xbox 360 games consoles, the Windows 7 operating system, the Internet Explorer browser and Windows Media Player.
However, the search firm has not been able to enforce a ban because a US judge intervened.
He wants to weigh up Microsoft's claim that Google had demanded an unreasonable licence fee for the H.264 video patents at the heart of the case.
Google is obliged to offer its technologies to everyone in return for a "reasonable" fee after accepting they were critical to the use of the video encoding format.
The case is set to go to trial on 13 November. Microsoft has said it would pay a licence for the technology if a "fair" price was set.