Abstract: A reading section outputs density information of a gradation pattern image of a recording member. A gradation correction characteristic generation section generates a first gradation correction characteristic f(x). At first image quality adjustment, a detection section detects densities of patch pattern images on an image carrier, and the gradation correction characteristic generation section generates a second gradation correction characteristic g(x). At normal image quality adjustment, the detection section detects densities of patch pattern images on the image carrier, and the gradation correction characteristic generation section generates a second gradation correction characteristic g?(x). A calculation section calculates a difference gradation correction characteristic g?(x) between the gradation correction characteristic g(x) and the second gradation correction characteristic g?(x).

Abstract: An image forming apparatus is provided with a storage device having storage areas divided corresponding to a characteristic value allocated for each print requesting person. Upon receiving print data and a characteristic value from an external device, the image forming apparatus stores the print data into a storage area which has been allocated the same characteristic value as the received characteristic value. The image forming apparatus subjects print data stored in the storage areas in the storage device to image formation processing on a storage area basis.

Abstract: An image forming apparatus includes a toner bottle, a supply unit that supplies toner from the toner bottle to a downstream side, a door that is openably provided to execute toner replenishment, an opening/closing sensor that senses opening/closing of the door, and a unit that renders the supply unit inoperable if the door is open. If the opening/closing sensor detects the opening of the door, counting of the number of prints is started. Then, the control unit detects whether the door is closed. If the door is still opening, the control unit checks whether the number of prints has reached a predetermined value. If not, the control unit sets the image forming apparatus in a printing state. If yes, the control unit stops the printing operation. If the closing of the door is detected, the control unit resets the count value. Subsequently, the control unit determines whether the initial value of the number of prints, which is set through a control panel at the time of starting the printing operation, is reached.

Abstract: A toner container installed in an image forming apparatus includes a toner container main body having a predetermined length and in which toner is accommodated, a discharge port through which the toner is discharged from the toner container main body, a shutter which opens and closes the discharge port, a handle provided on the toner container main body, and a pressed portion provided on the toner container main body and which is pressed by the image forming apparatus to project the handle out from the image forming apparatus.