A recent study conducted by the Japan Patent Office on global trends in the Electric Vehicles industry found that 76 percent of the 16,670 patents filed for electric propulsion vehicles worldwide (here defined as pure electric vehicles, hybrids and fuel cell vehicles, yet excluding railroad vehicles) came from Japanese companies.
As you can note from the tables, Toyota has filed ''dramatically'' more patent applications than anyone else. What's surprising in this list is the fact that it only takes into account patent applications filed from 2001 to 2006, which is after the Prius debuted. Many more applications were filed in this time frame than in 1995-2000, and the numbers are still climbing.
For your better understanding Toyota is the undisputed world leader in hybrid vehicle sales, and the Toyota Prius is a full hybrid electric mid-size car which first went on sale in 1997, making it the first mass-produced hybrid vehicle. The Prius is the most fuel efficient gas car currently sold and it is rated as among the cleanest vehicles sold based on smog forming and toxic emissions (89g/km). Toyota has just shown also a plug-in version and indicated that it plans to sell tens of thousands of plug-ins to the public soon.
This is a good example to show that to win in patent wars is always necessary to keep improving your technology, still hard-working, developing and registering again...