Now, in a move rich with irony, Google has accused Apple (AAPL) of ripping off its patents. And rather than attacking a proxy, it has filed suit directly against Cupertino in the U.S. International Trade Commission.

The claim, according to press statements issued to Bloomberg and the
Wall Street Journal
, is that Apple’s iPhone, iPad and iPod Touch infringe seven of the roughly 17,000 patents Google inherited when it bought Motorola Mobility just over a year ago.

“We would like to settle these patent matters,” said a spokesperson for Google’s Motorola division, “but Apple’s unwillingness to work out a license leaves us little choice but to defend ourselves and our engineers’ innovations.”

The filing has not yet been made public. and Google has been a little vague about what patents Apple may have infringed — except to say that they are not the kind of standards-essential patents that Motorola had earlier tried and failed to use against Apple. (See here.)

According to TechCrunch‘s Frederick Lardinois, the patents in question involve location reminders, e-mail notifications, video playback and Siri, and were deemed serious enough to demand an import ban against nearly every iOS product Apple makes.

Cynics might point out, as FOSS Patent‘s Florial Mueller did Saturday, that Google’s suit was filed only days before the expected arrival of what could be two pieces of bad legal news for Mountain View:

• On Thursday, the ITC is scheduled to issue a final ruling on a suit Motorola Mobility brought against Apple before it was acquired — one that Mueller thinks likely to be decided in Apple’s favor
• On Wednesday, the  jury is scheduled to begin deliberations in the multi-billion dollar Apple v. Samsung trial — a trial that most court watchers feel has not been going well for the world’s largest manufacturer of Android phones.

Google, says Mueller, may be hoping to show its manufacturing partners at this critical juncture that it has a patent war chest equal to Apple’s.

It may also be trying to to prove to Wall Street that it wasn’t pouring money down the drain last August when it spent a whopping $12.5 billion to buy Motorola Mobility.