PURPOSE: To make the edge of a read image signal sharp by leading read picture elements and circumferential picture elements on an original to a detector through pinholes and an optcial fiber respectively, and performing photoelectric conversion and then subtracting a circumferential picture-element signal from a read picture-element signal.

CONSTITUTION: An image signal from a read part 3A of an original is condensed through a lens 4 to form its image on a pinhole plate 31. Part of the image signal, which corresponds to fine picture elements centering on an optical axis 4A in the read part 3A, passes through the 1st pinhole and is sent to a detector through an optical fiber 32-1, etc., and after photoelectric conversion, the result is supplied to a subtractor 49 through an adder 48 and a terminal 43. An image signal which corresponds to picture elements at the circumference of a minimum picture element in the image signal imaged on the plate 31 passed through the 2nd pinhole and is sent to detectors 34∼37 through optical fibers, and after photoelectric conversion, the results are sent to the subtractor 49. The subtractor 49 subtracts the image signals of the circumferential part from the image signal of the fine picture element to output a composite signal, which is added by an adder 48 to the image signal from the detector 33.