Patent ID: 8395600

Claim:
An user interface device comprising: an imaging device which takes an image of an imaging range in which a hand is placed along a predetermined insertion direction; a tip area detecting module which detects a tip area in the insertion direction from the image taken by the imaging device; a tip area locating module which locates a position of the tip area in the imaging range and sets a position of the tip area as a tip position; a verifying module which verifies whether the tip position indicates a position of an actual fingertip based on at least one of a size of the tip area and an area of the tip area; and an outputting module which outputs coordinates of the tip position as coordinates of the actual fingertip if the tip position is verified as the tip position of the actual fingertip; wherein the tip area detecting module uses a first image which is the image taken by the imaging device and a second image which is an image obtained by shifting the first image parallel to the insertion direction, and detects a non-overlapping area generated on a distal end side in the insertion direction between the first image and the second image as the tip area; the tip area detecting module detects a plurality of non-overlapping areas as potential tip areas, when a plurality of non-overlapping areas are separately detected by inserting a plurality of fingers into the imaging range; and the verifying module determines whether at least one of the non-overlapping areas is an actual fingertip area or not based on whether a value S/d estimated as a finger width is in a predetermined range or not, where a value S is a total area of the image, and a value d is a sum of distance between each non-overlapping area and an edge of the imaging range, the edge being located on an entering side of the insertion direction.