here, and an excerpt:
11th August 1986: The US Patent Office accidentally grants another LZW patent, this time to IBM, due to patent examiners not realising that the Sperry and IBM applications claimed for exclusive 17 year rights on the same algorithm. For their part, IBM has not made use of the patent publicly, probably out of fear of having it invalidated and revoked by Sperry.
Even your link mentions the second patent is for the *same* algorithm, so the patent would most likely not stand if tested. |
