PURPOSE: To make the title device compact and to lower its costs by using an adhesive type image sensor in order to convert uneven optical pattern information into an electric signal.

CONSTITUTION: A parallel beam flux 2 emitted from a light source 1 is made incident on a prism at an angle in a prescribed range, and for example, a finger 4 to be detected object is pushed onto a reflective surface 3a of the prism 3. An outgoing light 5 from the prism 3 becomes a contrast image corresponding to the striped pattern of a finger print 4a, light pattern information is obtained, inputted to a 2-dimensional adhesive type image sensor 6, converted into the electric signal, and inputted to a processor 10 as an output signal 9. The adhesive type image sensor 6 is operated so that uneven picture data may be image- formed and converted into the electric signal as the optical information of the rugged pattern at directly approximate position, and it has a small and thin shape. Thus, the small and inexpensive input device can be obtained.