This aims at providing a hinge device compact in size, and at securing a space sufficient for an FPC, etc. The sealed housing includes a front plate, a back plate and a plurality of side walls affixed between the front plate and the back plate so that the front plate, the back plate and the side walls define an interspace region. A first operation decodes the detected signal, and determines phase coils of the motor through which a current should pass to rotate the rotor and the energization direction. The second gap is smaller than the first gap in the conveying direction of the recording sheet. An adhesive tape-like gasket is interposed between an outer periphery of the end plate and an inner surface of a sleeve so as to cover an outer end portion of the slit.