An image forming apparatus includes: an image bearing member for bearing a toner image; a belt for conveying the toner image; and a transfer device for rubbing the belt, and a surface of the transfer device, which is brought into contact with the belt includes linear concave portions or linear convex portions. Displacement of the coil relative to the armature is generated by forces corresponding to magnetic field lines generated by the coil, concentrated in the armature and the yoke, and directed essentially through an airgap situated between the armature and the yoke. The hanger element has a pulling portion for being pulled by a user and a shoulder extended outward from the periphery of one end thereof. A light emitting device is disposed within the through hole structure of the substrate. The example method includes re-filtering the remaining blood using a or the filtration device to remove additional plasma from the remaining blood. During operation of the system, the trial vector is compared with the exemplar vectors.