US Patent 4,464,650

Number:	4,464,650
Title:	Apparatus and method for compressing data signals and restoring the compressed data signals
Filed:	10-Aug-1981
Granted:	07-Aug-1984
Inventors:	Lempel, Ziv, Cohn, Eastman
Assignee:	Sperry Corporation (now Unisys)

Comment by FAQ:A compressor parses the input data stream into segments where each segment comprises a prefix and the next symbol in the data stream following the prefix. This is the original LZ78 algorithm.