Abstract: When a CPU receives an input signal that selects an operation mode through an operation mode selecting screen, the CPU determines whether or not the selected operation mode coincides with an operation mode stored in individual operation mode histories of an main body NVM. If both the operation modes do not coincide with each other, the CPU starts counting of a midway consumption of a toner representing the consumption of the toner used thereafter. Further, the CPU determines whether or not the count of the midway consumption arrives at a specified value. If the count arrives at the specified value, the CPU updates the individual operation mode histories of the main body NVM with the selected operation mode, and switches an existing operation mode to the selected operation mode.

Abstract: In the case of being mounted with any cartridge other than a genuine cartridge, which accommodates a toner other than a genuine toner, a user can select as an operation mode other than that corresponding to a genuine toner, through a UI device 18, making a correction to the consumption of a developer by combining conditions to be changed, such as increasing or decreasing the degree of a change (gradient) in a set value of the toner density with respect to the consumption of a developer (m1 or m2); increasing or decreasing a limit value (m1 or m2); varying an initial value (consumption=0) (m3); no making a change in a set value according to the consumption (m4); and no making a change in a set value according to the consumption, for example, by varying an initial value (m5)

Abstract: An image forming apparatus has at least one replaceable unit replaceably mounted to an image forming apparatus main body. The image forming apparatus outputs a message purporting that a reservation of an operation mode can be received, at the timing that a replacement timing of the replaceable unit which is currently mounted is close in time. If so, prior to the replacement of the replaceable unit which is current mounted, a reservation of an operation mode for a replaceable unit which is to be mounted next time may be received. Further, if the replacement of the replaceable unit is detected, the image forming apparatus starts the control according to the reserved operation mode.

Abstract: When a CPU receives an input signal that selects an operation mode through an operation mode selecting screen, the CPU determines whether or not the selected operation mode coincides with an operation mode stored in individual operation mode histories of an main body NVM. If both the operation modes do not coincide with each other, the CPU starts counting of a midway consumption of a toner representing the consumption of the toner used thereafter. Further, the CPU determines whether or not the count of the midway consumption arrives at a specified value. If the count arrives at the specified value, the CPU updates the individual operation mode histories of the main body NVM with the selected operation mode, and switches an existing operation mode to the selected operation mode.

Abstract: In the case of being mounted with any cartridge other than a genuine cartridge, which accommodates a toner other than a genuine toner, a user can select as an operation mode other than that corresponding to a genuine toner, through a UI device 18, making a correction to the consumption of a developer by combining conditions to be changed, such as increasing or decreasing the degree of a change (gradient) in a set value of the toner density with respect to the consumption of a developer (m1 or m2); increasing or decreasing a limit value (m1 or m2); varying an initial value (consumption=0) (m3); no making a change in a set value according to the consumption (m4); and no making a change in a set value according to the consumption, for example, by varying an initial value (m5)

Abstract: An image forming apparatus has at least one replaceable unit replaceably mounted to an image forming apparatus main body. The image forming apparatus outputs a message purporting that a reservation of an operation mode can be received, at the timing that a replacement timing of the replaceable unit which is currently mounted is close in time. If so, prior to the replacement of the replaceable unit which is current mounted, a reservation of an operation mode for a replaceable unit which is to be mounted next time may be received. Further, if the replacement of the replaceable unit is detected, the image forming apparatus starts the control according to the reserved operation mode.

Abstract: An image forming system adopting a dual-component developing system-for forming on an image carrier a toner image. The image forming system includes a charge unit for uniformly charging a surface of the image carrier, a developing magnet roll for giving a bias potential to toner, a switching device, such as a bipolar transistor, connected to a PWM image signal, a charge accumulating device, connected to the switching device, for accumulating charges, a total charge amount detection circuit for determining the total amount of charges, and a prediction device for predicting the total consumption of toner depending on the total amount of determined charges.

Abstract: An image forming system adopting a dual-component inversion developing system for forming on an image carrier a toner patch image used for detecting an image concentration and controlling an image forming condition such as toner concentration based on the concentration of the toner patch image. The image forming system includes a charge unit for uniformly charging a surface of the image carrier, a developing magnet roll supplied with a developing bias, and a patch forming unit for selecting voltage application conditions to the charge unit and the developing magnet roll so as to reverse the bias potential relationship between the developing magnet roll and a charge potential of the image carrier and forming a first toner patch image at a contrast potential between the charge potential of the image carrier and the bias potential.