I agree with the above posters that this guy is probably full of it - the cycle of fifths is a basic cornerstone of western tonality, and they have had those disc-converters for absolutely ever. There's no WAY it was only conceived in 1995.

I can't see how you can get a "patent" on what is basically a diagram, and am pretty sure one can't copyright a concept. Still it would probably be wise to check out application No. GB95086266.5 to see what it actually IS. You could also look in some old music theory books because sooner or later you will find this table, which should blow him out of the water.

I'm not a lawyer but I think the guy's a troll. (Did he provide you with a valid address & contact number?)