In an image forming apparatus including a power source for forming a secondary-transfer electric field at a secondary-transfer position and for forming a primary-transfer electric field at a primary-transfer position by applying a voltage to a transfer member to pass a current through a constant-voltage element, a potential of an image portion is controlled depending on a detection result of a detecting member.

A developing device including a developer container includes a containing chamber including an opening and configured to contain developer, a sealing member folded and configured to seal the opening, and an unsealing member to which one end of the sealing member is fixed. The containing chamber includes a first fixing portion and a second fixing portion that are fixed to the sealing member configured to seal the opening. A rotation center of the unsealing member is located at a position opposing an unsealing fulcrum of the unsealing member with respect to a virtual plane including the first fixing portion, the second fixing portion, and the opening when the sealing member is peeled from the containing chamber. Accordingly, a force required to peel the sealing member can be reduced.

A frame including an opening and configured to store a developer, a seal member configured to seal the opening, and an unsealing member including a fixing portion to which the seal member is bonded or welded are included, and by movement of the unsealing member the seal member is removed from the frame to open the opening.

An image forming apparatus includes a first image forming unit that forms a yellow image by an electrostatic charge image developing yellow toner; a second image forming unit that forms a magenta image by an electrostatic charge image developing magenta toner; a transfer unit that transfers the yellow image and the magenta image to a recording medium; and a fixing unit that fixes the yellow image and the magenta image to the recording medium, wherein a maximum absorption wavelength λmax (M) of the electrostatic charge image developing magenta toner at a wavelength of 360 nm to 760 nm is from 530 nm to 580 nm, and when an absorbance of the maximum absorption wavelength λmax (M) is standardized to 1, an absorbance at a wavelength of 450 nm is 0.20 or less and an absorbance at a wavelength of 400 nm is 0.10 or less.

A developing blade has a protrusion that protrudes toward a developing roller in an opposing portion facing the developing roller. When a height of the protrusion from an opposing surface that faces the developing roller at a position further toward a tip side than the protrusion is denoted by H (mm) and a length of the opposing surface extending toward the tip side perpendicular to an axial line direction of the developing roller is denoted by L (mm), when viewing a cross section perpendicular to a rotation axis of the developing roller, the following conditions are satisfied:

0.05≦H≦0.3, and

0.15≦L≦1.0.

A rotation detection mechanism has a pulse plate, an optical sensor, a holder, and an input gear. The pulse plate has a light-blocking portion formed on an outer peripheral surface thereof. The optical sensor has a detection portion that detects whether an optical path thereof is opened or interrupted by the light-blocking portion of the pulse plate. The holder has a bearing hole that rotatably supports a rotary shaft of the pulse plate. The rotary shaft has a convex portion formed on an outer peripheral surface thereof and thus is in a key shape when seen from an axial direction thereof. On an inner peripheral surface of the bearing hole, a groove portion is formed through which the convex portion passes when the rotary shaft is inserted into the bearing hole, and the bearing hole is in a circular shape when seen from an axial direction thereof.

A cleaning blade that contacts a cleaning target member having a cleaning target surface which moves, and cleans the cleaning target surface, includes a blade body; and a blade protrusion that is present at an end portion of a lower surface of the blade body near a distal end surface of the blade body, has a shape protruding outward in a thickness direction with respect to the lower surface, and has an inclined surface being a surface continued from the distal end surface and inclined outward in the thickness direction with respect to the lower surface and inward in a height direction with respect to the distal end surface from an end of the distal end surface near the lower surface. At least a portion of the incline surface is a contact surface that contacts the cleaning target member.

A lubricant supply device for supplying lubricant to an image carrier of an image forming device, the lubricant supply device including: a block of solid lubricant; a lubricant supply member scraping lubricant from the block and supplying the lubricant to the image carrier; and a spring applying a biasing force to the block in a second direction inclined with respect to a first direction from the block towards the lubricant supply member, a component of the biasing force in the first direction pushing the block against the lubricant supply member. Positions of the spring and the block relative to each other are such that, as the block decreases due to the scraping by the lubricant supply member, the angle between the biasing force and the first direction decreases and the component of the biasing force in the first direction increases.

The image forming apparatus includes a control unit that executes a supply operation to supply a toner charged with a regular charge polarity, to at least one abutting portion of a plurality of abutting portions, at the time of image non-formation, the plurality of abutting portions being formed by a plurality of cleaning members and a plurality of image bearing members, the control unit determining an image bearing member to which the most amount of the toner charged with the regular charge polarity is supplied, based on image formation information, the image formation information being information about an image formation executed before the supply operation is executed.

An image forming apparatus includes a belt unit capable of being inserted into and pulled out of the apparatus, the belt unit including a movable endless belt, a supporting frame supporting the endless belt and having an accommodating portion, a grip member which is provided on the supporting frame at a position outside the belt in a widthwise direction of the belt that is orthogonal to a moving direction of the belt and which is movable between a first position in which the grip member is projected out of the accommodating portion in a direction orthogonal to the widthwise direction and a second position in which the grip member is accommodated in the accommodating portion, and an urging member configured to urge the grip member in a direction from the second position toward the first position.