About Patent US6513002: Rule-based number formatter

It seems to me that many computer textbooks published before 1990 have include exercises about how to write a simple number translation program. I don't think this patent about a number translator is valid, since programs like these have been mentioned in a number of computer programming textbooks.

Does anyone have any specific examples of prior art for US6513002?

  • Hi Leo, can you please specify whether you are looking for specific examples of prior art, or are simply asking whether prior art from 1990 might be valid? Thanks! Nov 9, 2012 at 17:49
  • Filing date is 1998. Why look for prior before 1990? Nov 11, 2012 at 22:39

2 Answers 2


To the exact question - it is not valid and in force. IBM did not pay the maintance fee due in 2006 and it went abandoned in 2007. I looked it up in Lexis Total Patents. You can use the USPTO maintenance fee shopping window https://ramps.uspto.gov/eram/patentMaintFees.do or PAIR. PAIR has a captcha wall.


As a programmer, this patent seems to be meaningless. All it appears to do is take a spoken number and translates it into a numeric representation. This seems like what many voice-recognition gadgets already do, especially cell-phones. Plus, besides the initial voice input, the rest is a simple, common algorithm.

  • Can you cite a program or device that performs the functions described in the claims, or a publication that describes them, dating from before February 1997? That's what prior art means, and the question is even more specific. Claim 1 does seem to me to be have been obvious then, but some of the other claims are more substantial. Nov 9, 2012 at 21:41
  • I think your interpretation of the patent is incorrect. To me it appears to simply concern a method for taking a numerical value ("115") and converting it into a text string ("one hundred fifteen"). Everything based on "rules", which get "identified", of course. Another USPTO joke, if you ask me. Nov 11, 2012 at 22:42

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