An image forming apparatus configured to perform image formation using a component unit configured to be attachable to and detachable from a main body of the image forming apparatus is provided. The image forming apparatus includes: an access unit configured to access a storage device included in the component unit attached to the main body; and a control unit configured to control the access unit to read and update information stored in the storage device. The storage device includes a first area and a second area configured to store use information indicating a use state of the component unit, and updating of the use information stored in the first area by the control unit is configured such that updating only within a predetermined limit is permitted, and no limit is provided on updating of the use information stored in the second area.

A memory control device includes a memory control part that controls memory through an interface part in accordance with a predetermined communication regulation, an illegal access detection part that detects an illegal access to the memory according to an access state from the memory control part to the memory and a signal state of the interface part, and a signal control part that switches the signal state of the interface part from a write-allowed state, in which the interface part is able to be written, to a write-inhibited state, in which the interface part is protected from being rewritten, when the illegal access is detected by the illegal access detection part.

An image forming apparatus includes a main casing and a controller. A cartridge is to be attached to the main casing. The cartridge includes a memory stores usage status information indicating whether the cartridge is a new cartridge or an old cartridge which indicates a used product. The controller reads the usage status information stored in the memory in a case that attachment of the cartridge to the main casing is detected. The controller determines, based on the usage status information, whether the cartridge is the new cartridge or the old cartridge. The controller rewrites the usage status information to information indicating that the cartridge is the old cartridge in a case that the cartridge is determined to be the new cartridge. The rewriting is performed before the controller receives a print instruction and before the material or the part of the cartridge is consumed.

In an image forming apparatus a toner cartridge includes a toner memory storing toner identification information. The toner cartridge is detachably attachable to a drum cartridge. The drum cartridge includes a drum memory storing drum identification information. The drum cartridge is detachably attached to the main-body casing. A controller performs a request process to request execution of a density correction process to correct a density of developer, in a case where a toner identification information determination process determines that the toner identification information stored in the toner memory does not match the toner identification information which is stored in the main-body memory in a toner identification information storing process or a drum identification information determination process determines that the drum identification information stored in the drum memory does not match the drum identification information which is stored in the main-body memory in the drum identification information storing process.

An image forming apparatus which is capable of prompting a user to replace a process cartridge. The process cartridge is comprised of a plurality of components. At least CPU executes instructions to obtain life span information indicating life spans of the components of the process cartridge, determine whether or not the process cartridge is a specific process cartridge for which life span information on a part of the components of the process cartridge is obtained whereas life span information on all the components of the cartridge is not obtained, calculate a life span of the process cartridge, and provide notification of the calculated life span of the process cartridge. When the process cartridge is the specific process cartridge, the life span of the process cartridge is calculated based on only the obtained life span information on the components.

An image forming apparatus includes a photosensitive member; a charging member configured to electrically charge the photosensitive member; a developing device configured to form a toner image by supplying toner to the photosensitive member; a transfer member configured to transfer the toner image from the photosensitive member onto a toner image receiving member; a cleaning member provided in contact with the photosensitive member and configured to remove the toner remaining on a surface of the photosensitive member after transfer; and a controller configured to carry out a process for notifying information on a lifetime of the charging member, on the basis of use amount information on a use amount of the charging member and contact pressure information on contact pressure applied by the cleaning member to the photosensitive member.

In an image forming apparatus, a controller performs processes in accordance with an operation mode settable to one of a first subscription mode and a second subscription mode. The first subscription mode corresponds to a first subscription in which a specific-color cartridge is a subscription subject and a non-specific-color cartridge is not the subscription subject. The second subscription mode corresponds to a second subscription in which both the specific-color cartridge and the non-specific-color cartridge are the subscription subject. The controller performs restricting usage of the non-specific-color cartridge in a case where the first subscription mode is set as the operation mode and the type information of the non-specific-color cartridge indicates the subscription type, compared to a case where the second subscription mode is set as the operation mode and the type information of the non-specific-color cartridge indicates the subscription type.

A cartridge configured to accommodate a developing agent may include a detection gear, a first protrusion, and a memory. The detection gear may be rotatable about a first axis extending in a predetermined direction. The first protrusion may be movable with rotation of the detection gear. The memory may include a first storage region storing a first yield information representing at least one of amount of the developing agent in the cartridge and the number of printable sheets by the developing agent in the cartridge, wherein at least one of the amount of the developing agent and the number of sheets by the developing agent in the cartridge may be confirmable based on the first yield information and the first protrusion.

An image-forming apparatus includes: a toner cartridge configured to accommodate toner; a drum cartridge for use with the toner cartridge; and a controller. The drum cartridge includes a photosensitive drum, and a drum memory storing a first type information indicating a type of the drum cartridge. The controller is configured to communicate with the drum memory. The controller is configured to perform: reading the first type information from the drum memory; and changing an operation of the image-forming apparatus based on the type indicated by the first type information.

In an image forming apparatus a toner cartridge includes a toner memory storing toner identification information. The toner cartridge is detachably attachable to a drum cartridge. The drum cartridge includes a drum memory storing drum identification information. The drum cartridge is detachably attached to the main-body casing. A controller performs a request process to request execution of a density correction process to correct a density of developer, in a case where a toner identification information determination process determines that the toner identification information stored in the toner memory does not match the toner identification information which is stored in the main-body memory in a toner identification information storing process or a drum identification information determination process determines that the drum identification information stored in the drum memory does not match the drum identification information which is stored in the main-body memory in the drum identification information storing process.