For the fifth year in a row, computer maker IBM has earned more U.S. patents than any other organization. Of the 120,000 utility patents the U.S. Patent and Trademark Office issued last year, 1,724 went to IBM inventors. The company says more than 500 of the inventions are already in products. Among them: U.S. Patent 5,675,329, which doubles the usefulness of each computer keyboard key depending on how hard the key is struck. Force sensors attached to the keys can differentiate between a normal level of force and a greater force, performing two different functions with each different depression. Behind IBM in the number of patents received in 1997 are Canon with 1,378, NEC with 1,095, Motorola with 1,058, and the U.S. government with 923.