A document conveying apparatus for a document processor has a pair of width restriction members for correctly positioning documents to be processed. The width restriction members are movable in the width direction of the document processor. First and second rack-and-pinion mechanisms are spaced apart in the document conveying direction and are interlocked so that the racks of both mechanisms move together in a synchronized manner. Each width restriction member is coupled to two of the racks that move in the same direction.