An original is first illuminated with a light beam of white color or a wavelength adapted for reading of the original, and an optical image of the original is focused on a photosensitive drum previously charged uniformly, to form an electrostatic latent image on the photosensitive drum. Thereafter, the photosensitive drum is scanned with a laser beam, and a discharge current attendant on the scanning is detected and converted into an electric signal representative of the optical image. Thus, a monochromatic laser can read graphic records of any color.
A two-dimensional image sensor includes a two-dimensional photoconductive layer. A flat common electrode is formed on one major surface of the two-dimensional photoconductive layer. A pin electrode array having a plurality of pin electrodes aligned in a first direction is disposed above a second major surface of the two-dimensional photoconductive layer. An optical fiber lens array is fixed to the pin electrode array in order to apply optical image onto the second major surface of the two-dimensional photoconductive layer at a same time when a high voltage is applied by the pin electrodes. A shift means is connected to the pin electrode array to shift the pin electrode array and the optical fiber lens array in a second direction which is perpendicular to the first direction. Electric current is obtained at the flat common electrode, which represents the optical image applied by the optical fiber lens array.
