We hope this may help answer some similar questions you have. The LZW patent covers methods and apparatus for lossless compression and decompression of digital data.
Equivalent patents are also pending in Japan.
Data compression and decompression is a critical aspect of data transmission and storage and is very much of interest to Unisys and the industry. The patent is the result of research done by Terry Welch at Sperry Corporation in the early 1980s that extended previous work by researchers Lempel and Zev. Sperry Corporation was granted the U.S. patent in 1985. Sperry and Burroughs merged in 1986 to form Unisys, thus Unisys became the owner of the Sperry patents. It is a very efficient compression method and a highly advantageous way of compressing and decompressing data for a wide variety of purposes.