SanDisk targeted in MP3 patent suit
Flash memory manufacturer SanDisk has been sued by a US business for patent infringement over MP3 technology.
Hybrid Audio filed its lawsuit (pdf) at the US District Court for the District of Massachusetts on Tuesday, November 29.
The US company argued that SanDisk has infringed US patent number 6,252,909, titled “Multi-carrier transmission system utilising channels of different bandwidth”.
The patent was first registered at the US Patent and Trademark Office (USPTO) in 2001 by biometrics software company Aware.
In 2004, a reissue application was filed for the ‘909 patent with certificate number RE40,281 and Hybrid Audio-Texas was assigned all rights to the patent from the previous owner, Aware.
In 2011, Hybrid-Audio Texas filed a patent infringement lawsuit against other parties over its ‘281 patent. Hybrid-Audio Texas alleged that certain elements of MP3 technology infringed the ‘281 patent. The case was resolved with the parties.
According to the latest suit, Hybrid Audio-Texas sent SanDisk a letter in January 2011 saying that some of the company’s products infringed claims of the ‘281 patent.
In 2012, a re-examination request was filed for the patent at the USPTO and in December 2015 the ‘281 patent received the examination certificate RE40,281 C1.
In the suit, the re-examined C1 patent, the original ‘909 patent and the RE40, 281 patent are referred as RE281C.
The RE281C patent expired in September 2012, 20 years after the priority filing date of the original patent application.
Hybrid Audio-Texas was constrained from seeking royalties or filing lawsuits during the pendency of the most recent re-examination, June 2012 to December 2015.
In March this year, Hybrid Audio-Texas assigned all rights of the RE281C patent to Hybrid Audio.
In the latest suit, Hybrid Audio is seeking royalties for the infringement of its RE281C patent, which covers signal processing technology used in certain MP3 technologies.
Hybrid Audio argued that SanDisk infringed several claims of the patent and used the technology in its Sansa e200 series, Sansa M200 series, Sansa Fuze, Sansa View, and Sansa slotMusic Player products.
Hybrid Audio is asking for damages, reasonable and non-discriminatory royalties, interest, costs, expenses, attorneys’ fees and a trial by jury.
