Sony Corp. and three other companies that helped invent Blu-ray movie discs are suing Imation Corp., claiming the U.S. data-storage firm broke patent laws by selling blank, recordable versions of the discs.

In a lawsuit filed in U.S. District Court in Wilmington, Delaware, Sony and the other consumer electronics makers allege that Imation violated several patents related to Blu-ray technology, which allows a sharper picture than traditional DVD movie discs.

Selling packages of blank Blu-ray discs with the official logo violates the patents and encourages buyers to break the law whenever they record something, the complaint claims.

Imation, based in Oakdale, Minnesota, is aware that "its Blu-ray products, including Blu-ray discs, are especially made for use in an infringement of the patents," the complaint states.

Ken Kadet, an Imation spokesman, declined comment.

In 2009, Sony, Panasonic Corp., Pioneer Corp. and Koninklijke Philips NV pooled patents related to Blu-ray technology in a holding company called One Blue LLC. That company oversees Blu-ray licensing.

Blu-ray is the main standard for watching movies at home in high definition. The format is backed by the major film and television studios and was developed by a group of consumer electronics makers that included Sony.