Abstract: A common electrode driver includes an inverting amplifier including a first resistor, a second resistor, and an operational amplifier, and a resistance ratio adjustment circuit that adjusts, in accordance with a length of one horizontal scan period, a resistance ratio being a ratio of a resistance value of the second resistor to a resistance value of the first resistor. A feedback voltage is provided to one end of the first resistor. The resistance ratio adjustment circuit sets the resistance ratio when second driving is performed, in which a length of one horizontal scan period is a second time longer than a first time, to be smaller than the resistance ratio when first driving is performed, in which a length of one horizontal scan period is the first time.

Abstract: An optical scanning device includes an air-tight casing, an air-tight container and a tube-like member. The air-tight casing is configured to accommodate at least a polygon mirror and a driving unit that rotates the polygon mirror. The air-tight container is disposed at a distance from the air-tight casing and outside an outer wall surface vertically above the air-tight casing. The tube-like member is configured to communicatively connect an inside of the air-tight casing and an inside of the air-tight container.

Abstract: A sheet post-processing apparatus having a sheet tray, a sheet transportation path for guiding a sheet into the sheet tray, a bypass path bypassing a part of the sheet transportation path for guiding a sheet into the sheet tray, a post-processing mechanism for performing a post-processing operation on one set of sheets retained in the sheet tray, and a sheet transportation mechanism for feeding the sheet into the sheet tray. During the post-processing operation performed on the one set of sheets previously fed into the sheet tray, the first sheet of the next sheet set is once stopped in one of the transportation path and the bypass path, and the second sheet of the next sheet set is introduced into the other of the bypass path and the transportation path. Upon completion of the post-processing operation performed on the one sheet set, the first and second sheets of the next sheet set are fed into the sheet tray.

Abstract: A recycle document feeder includes a partitioning unit (17) and action plates (19, 20). The partitioning unit (17) includes a partitioning bar (18). When the partitioning bar (18) is lowered, the leading edges of discharged document originals are stopped by the partitioning bar (18). The action plates (19, 20) guide the discharged document originals toward an upper side of the trailing edges of document originals yet to be fed, and push the trailing edges of the discharged document originals to transport the document originals for re-feeding thereof. The partitioning unit (17) and the action plates (19, 20) are driven by a common motor (47). Further, a partitioning unit driving mechanism (110) and an action plate driving mechanism (111) are provided for driving the partitioning unit (17) and the action plates (19, 20), respectively.