| |
| | ipedia.com: LZW compression algorithm Article (Site not responding. Last check: 2007-11-01) |
 | | It was reported in Debian Weekly News based on a comp.compression thread, that the Unisys patent in the USA expired on December 20, 2002 - 17 years and 10 days after it was granted. |
 | | Most other sources claim the patent expired in June 2003, 20 years after it was filed, because 35 USC §154(c)(1) specifies that patents subsisting as of six months after the enactment of the Uruguay Round Agreements Act last for the greater of 17 years after grant and 20 years after filing. |
 | | According to a statement on Unisys's web site, counterpart patents on LZW in the United Kingdom, France, Germany, Italy, and Japan have expired in June 2004, and the Canadian patent expired on July 7, 2004. |
| www.ipedia.com /lzw_compression_algorithm.html (883 words) |
|