Chinese companies to enter rare earth magnet area in the US after expiry of Hitachi patent?

An article titled Hybrid car batteries, iPhones may become cheaper notes consequences of expiry of patents to Hitachi on rare earth magnets. There is text


The expired US patent 5,654,651 covers magnets with neodymium, a rare earth element, and cobalt, according to Sun [ chairman of Shenyang General Magnetic Co ].



One notes that US 5,654,651 [to Hitachi] is titled CMOS static logic circuit with abstract


A static logic circuit employs pull-down type logic gates having logic transistors forming a power supply current path and logic transistors forming a grounding current path and having current drive abilities higher than those of the logic transistors forming the power supply current path, and pull-up type logic gates having logic transistors forming a power supply current path and logic transistors forming a grounding current path and having current drive abilities lower than the logic transistors forming the power supply current path, and comprises logic series formed by alternately cascading the two types of the logic gates. The static logic circuit is provided with signal merged logic circuits each of which provides a signal having a high speed falling transient and a high speed rising transient by merging the output signals of the logic series.



The word "magnet" does not appear in the patent text.

Bloomberg has a related article China Takes on Hitachi as 17-Year-Old Rare Earth Patent Ends. The Bloomberg article refers to the same US Patent.


The expired U.S. patent 5,654,651 covers magnets with neodymium, a rare earth element, and cobalt, according to Sun. The Chinese alliance plans to sue Hitachi in the U.S. over several other patents that cover production, he said.