Samsung Electronics Co., the world's largest smartphone maker, on Thursday suffered a legal defeat against Apple Inc. on its home turf after a local court ruled that its archrival did not violate its patents. The court ruled that Apple, the No. 2 maker of smartphones, did not infringe on patents held by Samsung, dealing a further blow to the South Korean tech giant that has been in a multi-billion dollar patent war in the courts of more than 10 countries, including the U.S. and Japan.