Patent application number | Description | Published |
20130177328 | IMAGE FORMING APPARATUS - An image forming apparatus includes a photosensitive member (drum); a rotatable charging member for electrically charging the drum; a bias applying device for applying a charging bias to the charging member in the form of a DC voltage biased with an AC voltage; a current detector for detecting an AC current passing between the charging member and the drum; a temperature and humidity detector; a setting device for setting a condition of the charging bias on the basis of a plurality of detected AC currents passing between the charging member and the drum when a plurality of AC voltages depending on an output of the temperature and humidity detector are applied to the charging member; and a corrector for correcting the set condition of the charging bias on the basis of an output of the current detector when a predetermined AC voltage is applied to the charging member. | 07-11-2013 |
20130302053 | IMAGE FORMING APPARATUS - An image forming apparatus of a representative configuration of the present invention includes a photosensitive drum, which carries an electrostatic latent image, and a developing sleeve, which carries a two-component developer and develops the electrostatic latent image on the photosensitive drum into a toner image. Moving directions of the photosensitive drum and the developing sleeve are opposite at an opposing portion in a developing device having a speed changing portion, which changes the driving speed of the developing sleeve, and a controller, which switches a target speed of the developing sleeve so that it is driven at a second velocity, before it is driven at the first velocity set in a lower speed mode, when the lower speed mode is executed in which the photosensitive drum is driven at a lower speed than in the normal image forming. | 11-14-2013 |
20140044448 | CHARGING DEVICE - A grid of a charging device is cleaned without causing the grid to contact a member to be charged. In this structure, to suppress non-uniform charging due to wear of the grid, which is pulled toward a discharge electrode, for a long time, first and second protective layers are provided. The first protective layer is provided on a surface of a base member of the grid that faces the cleaning member. The second protective layer is provided on a surface of the base member that faces the pressing member. The second protective layer is thicker than the first protective layer. | 02-13-2014 |
20140044449 | CHARGING DEVICE - A shutter that suppresses accumulation of discharge products on a photosensitive member is disposed between a grid and the photosensitive member. In this structure, to suppress corrosion of the grid due to the discharge products for a long time, first and second protective layers are provided. The first protective layer is provided on a surface of a base member of the grid that faces the discharge electrode. The second protective layer is provided on a surface of the base member that faces the shutter. The second protective layer is thicker than the first protective layer. | 02-13-2014 |
20140064811 | IMAGE FORMING APPARATUS - The present invention provides an image forming apparatus including a charger that includes a case surrounding the discharge electrode and having an opening on the photosensitive member side and a grid disposed in the opening and having a mesh area, a shutter that includes the fiber opening and closing the opening, and first and second contact members that are disposed on a downstream of the charger and an upstream of the cleaning blade in a rotational direction of the photosensitive member and come in contact with areas of the photosensitive member corresponding to both longitudinal ends of the mesh area of the grid. | 03-06-2014 |
20140147140 | IMAGE FORMING APPARATUS HAVING CHARGING MEMBER FOR CHARGING PHOTOSENSITIVE MEMBER - An image forming apparatus having a photosensitive member, a charging member that charges the photosensitive member to form a charged surface on a surface of the photosensitive member, an applying unit that applies to the charging member a charging bias composed of a direct voltage superimposed with an alternating voltage, and a toner image forming unit that forms a toner image on the charged surface. A current flowing through the charging member when the charging bias is applied to the charging member is detected by a current detection unit, and currents of different predetermined frequency components are respectively extracted from the detected current by extraction units. Based on the extracted currents, the alternating voltage of the charging bias is adjusted by an adjustment unit. | 05-29-2014 |
20150043941 | CHARGING DEVICE - A charging device includes: a casing provided with an opening opposing a member-to-be-charged; a discharging wire provided in the casing; a grid electrode provided in the opening; a shutter for opening and closing the opening; a cleaning member for cleaning the grid electrode; and a moving mechanism for reciprocating the shutter and the cleaning member along a longitudinal direction of the opening. The moving mechanism includes a driving member for being rotationally driven, a first moving member, held by the driving member, for moving the shutter with rotational drive of the driving member, and a second moving member, held by the driving member, for moving the cleaning member with the rotational drive of the driving member. The charging device further includes: a mechanism for forming an interval between the shutter and the cleaning member so that the cleaning member moves in advance of the shutter by a predetermined distance when the shutter moves in a closing direction; and a stopper for stopping movement of the cleaning member, and the second moving member includes a holding portion for permitting idling when the shutter moves in the closing direction toward the cleaning member, stopped by the stopper, with rotation of the driving member. | 02-12-2015 |
20150063860 | CHARGING DEVICE - A charging device includes: a discharging electrode; a casing surrounding the discharging electrode and being provided with an opening in a member-to-be-charged side; a grid electrode provided in the opening and provided with a mesh portion having a plurality of through holes; a cleaning brush, including a base material and a plurality of fibers held on the base material, for cleaning the grid electrode by entrance of a part of the fibers into the through holes while contacting a surface of the grid electrode in the discharging electrode side; a shutter capable of shielding between the member-to-be-charged and the grid electrode; and a moving mechanism for moving the cleaning brush and the shutter along a longitudinal direction of the grid electrode. When the shutter is moved in a closing direction, the cleaning brush moves in advance of a leading end portion of the shutter with respect to the closing direction by a predetermined interval or more. | 03-05-2015 |