11. The virtual input device of claim 1 , wherein the mapping relationship between characters and recognized gesture result is a mapping relationship between characters and different parts of four fingers except thumb.
11. The virtual input device of claim 1 , wherein the mapping relationship between characters and recognized gesture result is a mapping relationship between characters and different parts of four fingers except thumb. 12. The virtual input device of claim 11 , further comprising a character set switching unit for switching the recognized gesture to another set of characters.