An image forming device is provided with a housing formed with an opening, a cover configured to move between a closing position and an opening position, and a plurality of process cartridges including a first process cartridge and a second process cartridge. The first and second process cartridges respectively include first and second photosensitive drums configured to rotate about first and second drum axes both extending in a first direction. The first and second developing devices are configured to supply toner to the first and second photosensitive drums, respectively. The first and second supplying devices are formed with first and second supply ports through which the toner to be supplied to the first and second developing devices are provided, respectively. Both the first and second supplying ports are opened to outside the housing.

A cartridge is configured to be attachable to a main body of an image forming apparatus and configured to receive toner supplied from a supply container. The cartridge includes a supply port configured to receive the toner supplied from the supply container, a shutter member configured to cover the supply port, and a locking member. The locking member is moved from a lock position to an unlock position to allow movement of the shutter member by using electric power supplied from the main body.

An image forming device is provided with a housing formed with an opening, a cover configured to move between a closing position and an opening position, and a plurality of process cartridges including a first process cartridge and a second process cartridge. The first and second process cartridges respectively include first and second photosensitive drums configured to rotate about first and second drum axes both extending in a first direction. The first and second developing devices are configured to supply toner to the first and second photosensitive drums, respectively. The first and second supplying devices are formed with first and second supply ports through which the toner to be supplied to the first and second developing devices are provided, respectively. Both the first and second supplying ports are opened to outside the housing.

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.

An image forming device is provided with a housing formed with an opening, a cover configured to move between a closing position and an opening position, and a plurality of process cartridges including a first process cartridge and a second process cartridge. The first and second process cartridges respectively include first and second photosensitive drums configured to rotate about first and second drum axes both extending in a first direction. The first and second developing devices are configured to supply toner to the first and second photosensitive drums, respectively. The first and second supplying devices are formed with first and second supply ports through which the toner to be supplied to the first and second developing devices are provided, respectively. Both the first and second supplying ports are opened to outside the housing.

A belt unit includes a belt that is endless, a plurality of stretching rollers, a pair of side frames and one or more shafts. The side frames are each provided with bearing holes that rotatably support opposite end parts of the stretching rollers, and positioning holes into which opposite end parts of the shafts are inserted. The shafts each have formed therein a first engagement groove that engages with a first holding jig. The stretching rollers each have formed therein a second engagement groove that engages with a second holding jig. When the first engagement groove is in engagement with the first holding jig, the shafts are arranged opposite the positioning holes corresponding thereto, and have a phase thereof restricted in a circumferential direction thereof. When the second engagement groove is in engagement with the second holding jig, the stretching rollers are arranged opposite the bearing holes corresponding thereto.

A cartridge is configured to be attachable to a main body of an image forming apparatus and configured to receive toner supplied from a supply container. The cartridge includes a supply port configured to receive the toner supplied from the supply container, a shutter member configured to cover the supply port, and a locking member. The locking member is moved from a lock position to an unlock position to allow movement of the shutter member by using electric power supplied from the main body.

A cartridge is configured to be attachable to a main body of an image forming apparatus and configured to receive toner supplied from a supply container. The cartridge includes a supply port configured to receive the toner supplied from the supply container, a shutter member configured to cover the supply port, and a locking member. The locking member is moved from a lock position to an unlock position to allow movement of the shutter member by using electric power supplied from the main body.

A cartridge is configured to be attachable to a main body of an image forming apparatus and configured to receive toner supplied from a supply container. The cartridge includes a supply port configured to receive the toner supplied from the supply container, a shutter member configured to cover the supply port, and a locking member. The locking member is moved from a lock position to an unlock position to allow movement of the shutter member by using electric power supplied from the main body.

A developing cartridge includes a developing portion to supply toner, a toner storing portion to store the toner, a partition wall formed between the developing portion and the toner storing portion and having a toner supply section, and a storing-portion agitating member rotatably disposed in the toner storing portion to intermittently rotate to move the toner in the toner storing portion while the developing portion supplies the toner.