Patent US 4,451,929

A pattern discrimination method is disclosed which judges that, when the difference between the data from an object or subject to be inspected and previously memorized data of a standard subject falls within a first predetermined value, the object belongs to the same kind of the standard subject. In this case, the difference between the data of the object and the previously memorized data of the standard subject is compared with a second predetermined threshold value smaller than the first predetermined value. When the difference is smaller than the second predetermined threshold value, the memorized data is revised in response to the new data from the object.