Patent ID: 7176901

Claim:
A portable information terminal comprising: (1) an upper section selected from either a first upper section or a second upper section, wherein the first upper section comprises: a first display screen displaying information; a first detector detecting, when a position on the first display screen is pointed, the position and outputting a position signal; and a first converter converting the position signal output from the first detector to a digital signal in a predetermined format and outputting the digital signal, said first converter being specific to said first display screen and said first detector; wherein the second upper section comprises: a second display screen displaying information; a second detector detecting, when a position on the second display screen is pointed, the position and outputting a position signal; and a second converter converting the position signal output from the second detector to a digital signal in a predetermined format and outputting the digital signal, said second converter being specific to said second display screen and said second detector, and (2) a lower section provided with a processing section receiving the digital signal output from either the first or second converter, recognizing the position and processing information displayed on either the first or second display screen according to the recognized position, wherein said lower section is compatible with both the first upper section and the second upper section.