A search processing section searches information stored in an address database, using a first character series, e.g., a postal code input through an input device as a search key, for a second character series corresponding to an address. A character recognition processing section performs character recognition with respect to a predetermined area in the image, using a character dictionary, and generates candidates for a character series including a name or designation, a postal code, an address, etc. A character image selection processing section selects a character series corresponding to the searched second character series from the generated candidates. A character image storage section stores correlation between each of the characters constituting the selected character series and a character image thereof. A character dictionary learning processing section performs a learning process with respect to the character dictionary, based on the stored correlation between each character and the character image thereof.