An analog buffer for buffering an input voltage to an output line is provided. One or more gain adjustment surfaces calibrated to a reference illuminant type is stored. Preselected corners of four tiles are positioned in overlying relation to the base and are spaced apart from one another by the spacer arms. In addition, the composition comprises inorganic white pigments, fibrous or particulate additives, impact toughness modifier andor polymers different from, 0-25% by weight of a flame retardant. Based on the density average value, a correction value for controlling the correction-target photosensitive drum 3 is calculated, and rotational phase control is performed in accordance with the correction value. Or, a DC offset mode can be selected to reduce blocking artifacts in smooth regions where there is little motion.