An image forming apparatus includes a processor that derives, for each of a plurality of blocks of image data, a value indicating a toner amount to be used in forming a toner image by referring to a density of every pixel, of a plurality of pixels included in each block of image data, shifts a window, and outputs the window before shifting and the window after shifting, the window before shifting and the window after shifting overlapping with each other, and determines a fixing temperature for a fixing operation based on an analysis result of a first toner amount in the window that is output by referring to the toner amount of each block included in the window before shifting, and an analysis result of a second toner amount in the window that is output by referring to the toner amount of each block included in the window after shifting.

A control unit of the invention compares printing setting suitable for a determined type of a recording material and printing setting of the recording material input by a user, and in a case where a difference between the printing setting suitable for the determined type of the recording material and the printing setting of the recording material input by the user falls in a predetermined range, the control unit performs a printing operation in accordance with the printing setting of the recording material input by the user, and in a case where the difference is greater than the predetermined range, the control unit performs the printing operation by changing the printing setting of the recording material input by the user, which is used when the difference is smaller than the predetermined range.

An image forming apparatus includes a container that contains a developer, a temperature information acquisition unit that acquires temperature information of the container, and a control unit that controls an image formation operation for forming an image. During the image formation operation, the control unit executes a suspension operation for suspending the image formation operation in the case that tt.sub.oth(t.sub.oth0) is satisfied, where t is defined to be an elapsed time from when a temperature corresponding to the temperature information of the container exceeds a predetermined threshold temperature T.sub.th, and where t.sub.oth is defined to be an exceeding time threshold value related to a period during which the temperature corresponding to the temperature information of the container remains higher than the threshold temperature T.sub.th.

An image forming apparatus according to one embodiment includes a maintenance management prediction device that predicts and determines the necessity of maintenance for a fixing unit, the type of the required maintenance, and the like by obtaining the difference between initial data (an initial detected temperature and an initial temperature estimation value) and latest data (a latest detected temperature and a latest temperature estimation value) of the fixing unit and comparing the difference to a predetermined range. Based on the comparison of the difference to the predetermined range the prediction device issues or not warning information.

Provided is a heater including: a substrate that has electrical conductivity; a first insulation portion that is provided on a first surface of the substrate, has an insulation property; at least one heat generation body that is provided on the first insulation portion; a second insulation portion that is provided on a second surface of the substrate which is opposite to the first surface, has an insulation property; at least one detection unit that is provided on at least one of the first insulation portion and the second insulation portion; and a first wiring which is provided on at least one of the first insulation portion and the second insulation portion, and in which one end is electrically connected to one terminal of the detection unit and the other end is electrically connected to the substrate having the electrical conductivity.

An image forming apparatus according to one embodiment includes a maintenance management prediction device that predicts and determines the necessity of maintenance for a fixing unit, the type of the required maintenance, and the like by obtaining the difference between initial data (an initial detected temperature and an initial temperature estimation value) and latest data (a latest detected temperature and a latest temperature estimation value) of the fixing unit and comparing the difference to a predetermined range. Based on the comparison of the difference to the predetermined range the prediction device issues or not warning information.

An image forming apparatus includes four photosensitive members, a first optical scanning unit, a second optical scanning unit, a first detection unit, a second detection unit and a control unit. The first optical scanning unit draws a first reference image and a first opposite image. The second optical scanning unit draws a second reference image and draws a second opposite image. The first detection unit detects the internal temperature of at least one of the first optical scanning unit and the second optical scanning unit. The second detection unit detects an apparatus internal temperature within an apparatus main body. The control unit corrects positions of the drawing of the first opposite image, the drawing of the second reference image and the drawing of the second opposite image based on the amount of change in the internal temperature and the amount of change in the apparatus internal temperature.

The image forming apparatus is an image forming apparatus for forming an image on a recording material using an electrophotographic process, and includes a transfer section that transfers a toner image on an image bearing member onto a transfer-receiving member; and a hardware processor (transfer voltage controller) that controls a transfer voltage to be applied to the transfer section by correcting a reference transfer voltage with a correction amount that is based on an environmental change, wherein, the correction amount depends on at least the transfer voltage, and the hardware processor determines the correction amount for determining the transfer voltage for a current transfer by referring to the transfer voltage for an immediately preceding transfer.

An image forming apparatus includes an image forming unit, a fixer, first and second temperature sensors, and storage and control units. The fixer fixes an image formed on the sheet by pressing. The first temperature sensor is disposed away from the image forming unit and the fixer, and measures an ambient temperature. The second temperature sensor is disposed closer to the image forming unit than the first temperature sensor, and measures an ambient temperature. The storage unit stores one or more difference values between first and second temperatures measured by the first and second temperature sensors when a switching condition is satisfied. When a difference between the one or more difference values in the storage unit and a latest difference value is equal to or larger than a threshold, the control unit stores information indicating that a reference value for determining an abnormality is exceeded.

An image forming apparatus includes an image forming portion, a fixing unit including a fixing member, a heating member, and a temperature detection portion, and a control portion configured to execute warm-up processing. If a temperature of the heating member at a first timing in a period of time in which the heating member is being heated in the warm-up processing is a first temperature, a temperature of the heating member at a second timing that is in the period of time and that is later than the first timing is a second temperature, and a temperature of the heating member at a timing different from the first timing and the second timing is a third temperature, the control portion is configured to change a fixing condition used in the job, based on the first temperature, the second temperature, and the third temperature.