PURPOSE: To obtain a signal by forming many large size photosensitive elements with a photosensitive layer made of antimony trisulfide, amorphous selenium or the like, photoelecting a reflected light from an original face at the photosensitive elements, and reading sequentially the electric signal generated therefrom by a switch.

CONSTITUTION: Electrodes 2 separated in the form of stripes, the photosensitive layer 3 thereupon and an electrode 4 thereupon are formed on a substrate 1. The stripe electrodes 2 are connected to a scanning section 5 comprising shift registers and switches one by one by a jumper 6. A photoconductive layer made of, e.g., antimony trisulfide or an amorphous photodiode layer made of amorphous selenium is used as the photosensitive layer 3. Only a component of light reflected on an original 13 among the lights applied from a light source 14 in contact with the original 13 and at the back side of the substrate 1 is received onto the photosensitive layer 3 via a spacer 12 and a transparent electrode 4. The light source 14 supplies light from the surface of the spacer 13 at an angle in the degree that the incident light is not reflected fully. An average luminous amount near the exposed electrode 4 among the reflected lights from the original face is converted into an electric signal at the photosensitive layer.