Sony faces patent challenge to Blu-ray

Stephen Withers
Monday, 28 May 2007 03:07

Business IT - Technology

Three of Sony's divisions face a patent suit over the metallic layers used to reflect laser light in Blu-ray discs.

Target Technology claims that Blu-ray discs infringe a patent it filed last year concerning the use of certain metal alloys in the reflective or semi-reflective layers of an optical disc.

Target's patent describes a range of alloys comprising a high proportion of silver with small amounts of one or more other metals such as yttrium, scandium, copper and magnesium. These alloys are said to have better corrosion resistance than pure silver, and to offer the advantages of gold for this application but at a lower cost.

The patent is not specific to Blu-ray, but is couched in broad terms which could describe various types of optical storage media.

Assuming the court upholds Target's complaint, Sony will be faced with finding an alternative material for the reflective layers in Blu-ray discs or licensing the company's technology.

Sony's PlayStation 3 features a Blu-ray drive, and one of Australia's leading music and video retailers has announced Blu-ray will be the only prerecorded HD video format it will stock.