Patent ID: 7202860

Claim:
A coordinate input device comprising: a pair of cameras positioned in an upper left position and an upper right position of a display screen of a monitor lying close to a plane extending from the display screen of the monitor and views both a side face of an object in contact with a position on the display screen and a predetermined desk-top coordinate detection area to capture the image of the object within a field of view, each of the pair of cameras including infrared emitting diodes in the vicinity of an image lens for illuminating a coordinate detection field; a reflective outline frame formed of a member having a high reflectance and a member having a low reflectance running side by side along three sides of the display screen except a top side of the display screen so that a border line providing a sharp white and black contrast between the two members comes within the field of view of the two cameras; and a control circuit which calculates the coordinate value of a pointing tool pointing to a position within the coordinate detection field, based on video signals output from the pair of cameras, and transfers the coordinate value to a program of a computer, the positioning tool being selected from the group consisting of a user's finger and a pen which has a retroreflection member at its tip.