Analog BTSC licensing program
(early 1980s - 2004)

The dbx-tv companding noise reduction system used in BTSC was covered by several fundamental patents, most prominently US Patent 4,539,526 ("Adaptive Signal Weighting System"). These patents and the corresponding dbx trademark was licensed to over a hundred equipment makers (mostly TV and VCR makers) over the life of the patents. While from its introduction in 1984 through 1994 when THAT purchased the portfolio, it changed ownership several times, since 1994, the portfolio, technology, and dbx-tv brand have been solely in THAT's hands.

We at THAT retired the original analog licensing program in January of 2004 when the above mentioned patent expired. Since that time, all analog implementations of dbx-tv's BTSC noise reduction system have been free of any licensing requirements. Because it was based on analog technology, this IP portfolio never included any IP "cores" as modern DSP offerings do: it comprised patents, circuit design know-how, and rights to the dbx trademark only. As well, dbx, Inc's, as well as THAT's sole focus was on licensing equipment makers.