Authorities Cited: United States Patent and Trademark Office U.S. Patent No. 3,833,795 U.S. Patent No. 4,463,250 U.S. Patent No. 5,283,422 Supreme Court 365 U.S. 336, 346 477 U.S. 242, 248 477 U.S. 316, 323 520 U.S. 17, 27 535 U.S. 722, 733 Circuit Courts 53 F.2d 520 288 F.2d 930 982 F.2d 505, 506 991 F.2d 810 138 F.3d 1448, 1456 195 F.3d 1322, 1327-1328 200 F.3d 795, 811 329 F.3d 1372, 1377 339 F.3d 1352, 1368 363 F.3d 1321, 1331 376 F.3d 1339, 1343 415 F.3d 1303 231 F. Supp. 2d 626, 637 424 F. Supp. 2d 678