PURPOSE: To sort patterns in a short time at low cost with miniaturized constitution by image-forming picture information at four side parts of a pattern on the each sensor part and by photoelectrically converting and digitizing the information.

CONSTITUTION: Original 17 fixed on original fixing table 18 is irradiated with light from lighting light source 15. Pieces of picture information at four side parts 19aW 19d of a character on original 17 to be recognized are image-formed on diffusers 23aW23d via half-mirror 22 and optical image-formation system 21. Light beams entering duffusers 23aW23d are diffused into uniform beams, which is supplied to photoelectric converting elements 24aW24d and converted into electric signals. Half- mirror 22 prevents sensor parts from overlapping in position at four corners of the character. Signals from photoelectric converting elements 24aW24d enter electric circuit 26, where they are amplified by an amplifier, quantized by the analog/digital converter and sorted.