The tech world is abuzz about Amazon's new tablets, announced this morning at a press event in New York City. But will Amazon have to pay Microsoft royalties for using Android in at least one of its new tablets?

Amazon's Kindle Fire, which will sell for $199, runs on Google's Android software. (Amazon also announced other new offerings -- including a $99 Kindle Touch and $79 Kindle starter -- which don't appear as if they run on the Android platform. We'll update if we find out differently.)

The issue with devices that run on Android is that Microsoft says it has patents on technologies found in certain Android features. So it's gone after companies that use Android on their phones or tablets, either suing them or reaching licensing agreements with them.

Just this morning, Microsoft announced a patent agreement with Samsung in which Samsung will pay Microsoft royalties for mobile phones and tablets running Android.

Microsoft and Amazon already have a patent cross-licensing agreement that involves existing Kindles, according to CNET News.

[Update 4:36 p.m.: Microsoft and Amazon's cross-licensing agreement, reached in 2010, does not cover Android.

Microsoft declined to comment on whether it intends to either talk with, or a file a lawsuit against, Amazon over its new Android-based tablet.

Microsoft is protecting its intellectual property (IP) according to IP rules and also living by those rules, said Horacio Gutierrez, deputy general counsel for Microsoft. He noted that Microsoft has paid out more than $4.5 billion over the last decade in IP royalties to "third parties that hold IP that we believe are essential for our products to be shipped."]