A first replaceable unit is provided for use with a second replaceable unit in an electrophotographic image forming device. The first replaceable unit includes a latch movable between a latching position for latching the first replaceable unit to the second replaceable unit and an unlatching position for permitting the first replaceable unit to separate from the second replaceable unit. The latch is positioned to contact a latch catch on the second replaceable unit in order to prevent the first replaceable unit from separating from the second replaceable unit when the first replaceable unit is mated with the second replaceable unit and the latch is in the latching position. The latch includes a cam follower surface for contacting a camming surface on the second replaceable unit during mating of the first replaceable unit with the second replaceable unit to cause the latch to move toward the latching or unlatching position.

In some examples, an apparatus can include a print substance gauge to indicate a quantity of print particles an imaging device is capable of receiving at a particular time, and an authentication mechanism coupled to a locking mechanism, the authentication mechanism includes instructions to: determine a quantity of print particles within a print particle container, and unlock the locking mechanism when the print substance gauge indicates that the imagining device is capable of receiving the quantity of print particles within the print particle container.

A device (1) for controlling user access to at least one container (4) for dispensing printing material housed by a printing apparatus (5), the device (1) comprising an openable and closable barrier (2) corresponding to the container (4) and a lock for locking the barrier (2) in a closed position. The lock is overlapped by at least a portion of the barrier (2) both when the barrier (2) is in the closed position and when the barrier (2) is in an open position.

An image forming apparatus includes a release processing portion, a regulation processing portion, and a second restriction processing portion. The release processing portion releases regulation on removal of a developer storage portion when a storage amount of developer stored in an image forming portion is equal to or smaller than a second threshold smaller than a first threshold. The regulation processing portion regulates removal of the developer storage portion when the storage amount of the developer stored in the image forming portion is larger than the second threshold and removal of the developer storage portion has not been regulated. The second restriction processing portion imposes restriction on processing of the regulation processing portion when the regulation on the removal of the developer storage portion is released and a restriction condition is satisfied.

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.

The image forming apparatus includes a cartridge replaceable by detachably mounting to the image forming apparatus, a door that takes a closed state or an open state, a locking pin that switches a state of the regulation unit between a regulating state in which the replacement unit is prevented to be detached from the image forming apparatus and a release state in which the replacement unit is to be detachable from the image forming apparatus, and a lock control unit (a control unit) that makes a determination as to whether or not the state of the regulation unit is to be switched from the release state to the regulating state, at a predetermined timing when initial processing is completed after a power source is turned on or a state of the door becomes the closed state from the open state.

A light guide device includes: a housing main body; a side member attached to a side portion in the housing main body; a light guide body supported by the housing main body and including a light incident surface to which light enters; a light source substrate held by the side member and including a light element that emits the light toward the light incident surface; and a positioning portion configured to position the light element to a reference position with respect to the light incident surface. The positioning portion includes: an abutting member provided in the housing main body and configured to abut on a mounting surface in the light source substrate on which the light element is mounted; and an elastic member held by the side member and configured to press the light source substrate toward the light guide body to position the light element to the reference position.

A developing device configured to develop a latent image formed on a surface of an image bearer includes a rotator, a bearing, a holder, a first regulator, and a second regulator. The rotator includes a rotation shaft. The bearing supports the rotation shaft. The holder holds the bearing. The first regulator, disposed on any one of the bearing and the holder, regulates movement of the bearing such that the bearing does not fall toward one end side in an axial direction of the rotation shaft relative to the holder. The second regulator regulates movement of the bearing such that the bearing does not fall toward another end side in the axial direction relative to the holder after the bearing is attached to the holder.

An image forming apparatus includes: a first developing roller movable between a first contact position and a first separated position; a second developing roller movable between a second contact position and a second separated position; and a controller. When a sheet interval is shorter than a first interval and is longer than or equal to a second interval, the controller maintains the first developing roller at the first contact position even after the completion of its development for a preceding sheet, controls the first developing roller to start development for a subsequent sheet, moves the second developing roller to the second separated position after the completion of its development for the preceding sheet, moves the second developing roller again to the second contact position, and controls the second developing roller to start development for the subsequent sheet after the second developing roller is moved again to the second contact position.

An image forming apparatus, having first, second, third, and fourth photosensitive drums, first, second, third, and fourth developing rollers, a development-driving gear, a development motor, a first development gear train having a first gear, a second development-gear train having a second gear, a process-driving gear, a process motor, a first process-gear train having a third gear, and a second process gear-train having a fourth gear, is provided. The first development-gear train transmits a driving force from the development motor to the first and second developing rollers. The second development-gear train transmits the driving force from the development motor to the third and fourth developing rollers. The first process-gear train transmits a driving force from the process motor to the first and second photosensitive drums. The second process-gear train transmits the driving force from the process motor to the third and fourth photosensitive drums.