An unregistered trademark may be marked with "TM". In the United States, only trademarks registered with the US Patent and Trademark Office may be marked with "®". From what I understand, it's a lot more difficult to enforce an unregistered trademark than a registered trademark (but I am not an attorney, so don't pay much attention to what I say.)
A patent is different from a trademark. There are two kinds of patents, the first is a design patent, which protects how a product looks (but not what it does). The second is a utility patent, which protects what a product does, or manufacturing processes. Currently in the US patents expire in 20 years or less. In comparison, registered trademarks do not expire. |
