An image forming apparatus includes an apparatus body, an image carrier, a developing device, a toner container, a container cover, a driver, a lock mechanism and a lock restricting portion. The lock mechanism is switched to a locking state for locking the container cover in a closed state and an unlocking state for causing the container cover to transition from the closed state to the open state. The lock restricting portion obstructs a state change of the lock mechanism from the unlocking state to the locking state if the container cover is not attached to the apparatus body.

An image-forming device includes a main casing, a belt accommodated in the main casing, developing units arranged along the belt, a drawer configured to detachably support the developing units, the drawer configured to move to a position inside the main casing and to a position outside the main casing, and the drawer having a leading end and a trailing end in a pulling direction from the inside position to the outside position; and a guide configured to guide the drawer and to move between a first position and a second position when the drawer is at the inside position, the second position being farther from the belt than the first position from the belt. When the guide is at the second position, the guide is configured to be tilted downward relative to a horizontal direction such that the leading end is lower than the trailing end.

Provided is an image forming apparatus including: an apparatus main body; a plurality of units arranged adjacent to each other in the apparatus main body, and configured to be attachable to and detachable from the apparatus main body in the same insertion and removal direction; and a switching member 36 configured to be capable of taking any one of a first position in which attachment and detachment of one unit 4 of adjacent units among the plurality of units to and from the apparatus main body is allowed and attachment and detachment of another unit 5 of the adjacent units is restricted, and a second position in which the attachment and detachment of the one unit 4 is restricted and the attachment and detachment of the other unit 5 is allowed.

An image forming apparatus set (200) includes an image forming apparatus (100) and a mounting base (3) on which the image forming apparatus (100) is placed. The mounting base (3) includes a locking mechanism (R). When the image forming apparatus (100) is placed at a first position in the mounting base (3), the locking mechanism (R) restricts movement of the image forming apparatus (100) relative to the mounting base (3). The locking mechanism (R) includes a first locking mechanism (4) and a second locking mechanism (R2). The first locking mechanism (4) restricts movement of the image forming apparatus (100) in a first direction (D1) relative to the mounting base (3). The second locking mechanism (R2) restricts movement of the image forming apparatus (100) in a second direction (D2) relative to the mounting base (3). The second direction (D2) is opposite to the first direction (D1).

Measures for controlling an engagement force between a photo imaging plate and a developer roller in a printing device are described. A motor is operated to generate rotational motion. The rotational motion is translated into linear motion. The linear motion causes an adjustment to the engagement force between the developer roller and the photo imaging plate. A characteristic of the motor is monitored. The motor is controlled on the basis of the monitored characteristic in order to maintain a desired engagement force between the developer roller and the photo imaging plate.

A method for adapting a printer for operating with more colours, the printer including an inner framework and a dispenser assembly associable with said framework, includes the steps of application of at least one first quick release connector for electric cables at the dispenser assembly; and application of at least one corresponding second quick release connector at the inner framework of the printer.

There is provided a secondary transfer device for secondary-transferring a toner image primary-transferred on an outer peripheral surface of an endless annular intermediate transfer belt to a sheet at a predetermined secondary transfer position, the intermediate transfer belt having a predetermined width and being wound around a plurality of rollers and rotating, the secondary transfer device including: a pressure-releasing mechanism that displaces a secondary transfer roller to a pressing position and a separation position; a first drive that drives the pressure-releasing mechanism; a high-speed depressurization mechanism that temporarily depressurizes a nip pressure, at which the secondary transfer roller at the pressing position interposes and presses the intermediate transfer belt in a gap with respect to the opposite roller, when a leading end and a tailing end of a sheet pass between the secondary transfer roller and the intermediate transfer belt; and a second drive that drives the high-speed depressurization mechanism.

An image forming apparatus includes: a photosensitive drum; a developing roller; a separation mechanism for moving the developing roller between a contacting position contacting the photosensitive drum and a separated position separated from the photosensitive drum; a first tray; a first sheet feed mechanism for feeding a sheet from the first tray toward the photosensitive drum; a first sheet sensor for detecting passage of the sheet at a prescribed position; and a controller configured to perform: when a printing operation is performed onto the sheet fed from the first tray, feeding the sheet in the first tray to the prescribed position and maintain the sheet; moving, on or after the first sheet sensor detects the sheet, the developing roller to the contacting position; and feeding, after a prescribed time period has elapsed since the first sheet sensor detects the sheet, the sheet from the prescribed position toward the photosensitive drum.

A fixing device includes a pressure roller including a rotation shaft, a bearing that rotatably supports the rotation shaft, a first bracket mounted on a first end of the pressure roller in an axial direction thereof, and a second bracket mounted on a second end of the pressure roller in the axial direction thereof. Each of the first bracket and the second bracket includes a rotation shaft support face through which the rotation shaft of the pressure roller is inserted and a bearing support face disposed opposite an outer circumferential surface of the bearing. A first tab is mounted on the bearing support face of the first bracket. A second tab is mounted on the bearing support face of the second bracket. The first tab and the second tab are disposed upstream from the rotation shaft of the pressure roller in a recording medium conveyance direction.

A photo-interruptor unit includes a photo-interruptor including a light emitting component, a photosensing portion, and a hook portion configured to deform elastically in a deformation direction, and a supporting portion. The supporting portion includes an attaching surface, a hole through which the hook portion is inserted in an insertion direction, a guide portion configured to guide the hook portion so that the hook portion deforms in the deformation direction in a state where the photo-interruptor is moved in the deformation direction and a movement direction intersecting the insertion direction to be attached to the supporting portion, and a regulating portion configured to protrude from the attaching surface and configured to regulate a position in the movement direction of the photo-interruptor whose hook portion has been guided by the guide portion to a position where the hook portion is overlapped with the hole.