Barr and the other defendants argued, among other things, that Lilly's patents were invalid for technical reasons and for "double patenting" — the claimed new discovery being patented was obvious when compared to an earlier, original patent.
—Michael Kirkland, "Court rejects Prozac patent case," United Press International, January 14, 2002
NEC claimed in last week's filing that the patents are invalid "for failure to comply with the statutory requirements of Title 35, U.S. Code," and "for double patenting."
—J.D. Kidd, J.D and Robert Ristelhueber, "Japanese Split on TI Patents," Electronic News, March 31, 1986
Patent protection gives a company exclusive rights to sell a product for a limited number of years. (In the U.S., for example, pharmaceutical companies have exclusive rights to sell their products for 12 to 17 years.) Some companies try to extend that term by tweaking the product and claiming that the revised version is a "new use" that justifies a new patent. However, if the courts rule that the new use is obvious based on the original patent, then the new patent becomes an illegal
double patent.
