At last the Dolby Digital (AC-3) patent expires
Audio compression standard widely used as a standard format for movies and games "AC-3"(Dolby Digital:Dolby Digital), The related patents that remained until the end have expired on March 20, 2017.
The Last AC-3 Patent Expired on March 20, 2017
AC-3 that came out in 1992 is an audio compression standard popularized as an audio format for movies and television. AC-3 became standard also in DVD and Blu-ray, continued to evolve such as corresponding to 5.1 surround, net streaming service supporting AC-3 for live streaming also appeared, the most successful voice compression standards on digital sound It can be said.
The fact that AC-3, which has already been patented for more than 20 years since it was patented,Evergreening(Evergreening) "by a strategy called. Evergreening is the process of maintaining and continuing the exclusive use right granted to a large patent, by acquiring a new patent in which the patent has been partly modified in terms of technology, it is essentially a patent right It is a strategy commonly used in pharmaceuticals with a strategy of prolonging the validity period and dominating technology exclusively over a long term. Although the legal validity and validity of Evergreening itself is questionable and subject to criticism, users who are afraid of the risk of being accused of patent infringement are licensed from the patent owner for the prevention of trouble It is pointed out that paying royalties is common.
The AC-3 also exercises AC-3 exclusively by successively issuing new standards that improved AC-3, such as Dolby Digital Surround EX, Dolby Digital Live, Enhanced AC-3 (Dolby Digital Plus), Dolby True HD, We have maintained control, but March 14, 2017 is due "US 644936", March 19, 2017 is deadline"US 5890106"Patent expired on the contrary due to the expiration of its duration, all patents related to AC-3 have been lost. Incidentally,Ac3freedomday.orgAccording to the right holder Dolby Laboratories, at the venue of SEC 2015, he admitted that "the remaining patents on our Dolby Digital technology will expire from 2008 to 2017". However, in 2012, Dolby Laboratories will have a large amount of PanasonicSubmarine patent, And there is a possibility that the possibility that Dolby Digital related patents still exist is pointed out.
Until now, the licensing fee of AC - 3 was included in the selling price of AV equipment such as game machines and televisions, but it seems that the price of AV equipment may be lowered slightly as it becomes unnecessary in the future. Also, some of the software does not support AC-3 because it dislikes payment of license fee, but AC-3 may be supported again due to expiration of patent of AC-3. However, since AC - 3 itself is based on the old standard 25 years ago, there is a later generation standard such as DTS with higher performance, so there is a possibility that Dolby Digital will fade out.