CONTACTLESS BIODETECTOR

A biodetector permits formation of an image of the inner face of the hand or of a finger of a user when the hand or the finger (101) is placed in front of an image-forming device (11), at a defined height (F). The height is adapted such that the biodetection image is sufficiently clear and is indicated to the user by means of a sign (40) projected onto the outer face of the hand or of the finger. Such a biodetector does not require the hand or finger to be applied to a support surface, and it permits intuitive and rapid use of the biodetector.