Disclosed is an image forming apparatus which is capable of shifting to a standby state in which a heating rotating member is maintained at a first temperature during non-image forming, and to a sleep state in which a heater is turned off during non-image forming. The image forming apparatus turns on the heater before a predetermined time period elapses from when the image forming apparatus shifts to the sleep state such that the heating rotating member is maintained at a second temperature, which is equal to or less than the first temperature when the predetermined time period elapses from when the image forming apparatus shifts to the sleep state.

An image forming apparatus includes a forming unit, a transfer unit, a blowing unit, a temperature detection unit, and a control unit. The forming unit forms a toner image on a photosensitive member. The transfer unit transfers the formed toner image onto a recording material. The blowing unit takes outside air into the apparatus to generate an air flow for adjusting a temperature of the transfer unit. The temperature detection unit detects an ambient temperature outside the apparatus. The control unit controls driving of the blowing unit based on the detected ambient temperature. The control unit drives the blowing unit in a case where the detected ambient temperature is less than or equal to a first temperature threshold and a gradient value indicating a change in the detected ambient temperature is at least a first gradient threshold.

An environment management apparatus for inside of a machine includes an estimator and a generator. The estimator estimates an environment state in the machine in a case of executing a process under a predetermined control condition, from process execution data for instructing execution of the process. The generator generates, for the environment state estimated by the estimator, a time-series scheme for environment control during the execution of the process from a calculation result obtained by calculating a control condition which maintains the environment state to be less than or equal to a predetermined target value.

An image forming apparatus configured to form an image on a recording material includes a detection unit configured to detect a temperature of a first member, and an estimation unit configured to estimate a temperature of a second member, which is different from the first member. The estimation unit is configured to estimate, based on the temperature of the second member estimated by the estimation unit at a first timing, which is a timing before the image forming apparatus is powered off, the temperature of the first member detected by the detection unit at a second timing, which is a timing after the image forming apparatus is powered on, and information representing an operation history of the image forming apparatus until when the image forming apparatus is powered off, the temperature of the second member at the second timing.

An exposure apparatus for exposing a photosensitive member includes: a first chip that includes a plurality of first light-emitting portions arranged along an axial direction of the photosensitive member; a second chip, arranged at a different position from the first chip in the axial direction, that includes a plurality of second light-emitting portions arranged along the axial direction; and a control unit configured to output image data that is a set of binary bits each indicating a first or second value. A first part and a second part of the image data are output to the first and second chips, respectively. The control unit is configured to control a driving current supplied in each of the first and second chips based on a counted number of bits indicating the first value in the corresponding part of the image data.

To detect humidity, used are a first series connection circuit connecting a thermistor and a fixed resistor via a node, a second series connection circuit connecting a resistance change type humidity sensor and the thermistor via the node, and a third series connection circuit connecting the humidity sensor and the fixed resistor via the node. A predetermined voltage is applied across the first circuit to detect a first voltage indicating temperature through the node, and secondly across the second circuit to detect a second voltage indicating a first humidity through the node, and finally across the third circuit to detect a third voltage indicating a second humidity through the node. Then, the first voltage is compared with a reference voltage and judgment is made, based on a comparison result, to determine which of the second voltage and the third voltage is relevant to use as a basis for outputting the humidity as detected.

An environment management apparatus for inside of a machine includes an estimator and a generator. The estimator estimates an environment state in the machine in a case of executing a process under a predetermined control condition, from process execution data for instructing execution of the process. The generator generates, for the environment state estimated by the estimator, a time-series scheme for environment control during the execution of the process from a calculation result obtained by calculating a control condition which maintains the environment state to be less than or equal to a predetermined target value.

An image forming apparatus including a first temperature sensor inside a space between frames, a second temperature sensor outside the space between the frames, and a controller that, in a case where a first temperature by the first temperature sensor is higher than an inside threshold temperature, and a second temperature by the second temperature sensor is higher than an outside threshold temperature, performs simplex image formation at a first speed when simplex image formation is specified, and performs duplex image formation at a second speed lower than the first speed when duplex image formation is specified, and in at least one of a case where the first temperature is equal to or less than the inside threshold temperature and a case where the second temperature is equal to or less than the outside threshold temperature, performs image formation at the first speed.

A fixing device includes a motor, a heater, a power supply stopping portion, and a threshold setting portion. The motor rotates a fixing member that fixes a toner image transferred to a sheet onto the sheet. The heater heats the fixing member upon being supplied with power. In a case where temperature of the fixing device exceeds a threshold, the power supply stopping portion stops supply of power to the heater. The threshold setting portion changes the threshold from a first temperature to a second temperature higher than the first temperature in an acceleration period in which rotation speed of the motor increases, and changes the threshold from the second temperature to the first temperature when a deceleration period in which the rotation speed of the motor decreases starts.

A fuser configured to be removably attached to an image forming apparatus includes a heating rotatable body for heating a sheet, a heater for heating the heating rotatable body, a pressure rotatable body for nipping the sheet between the pressure rotatable body and the heating rotatable body, a temperature sensor for detecting a temperature of the heating rotatable body, a state detection sensor for detecting a state of the fuser, a fuser connector configured to be connected to a main body connector of the image forming apparatus when the fuser is attached to the image forming apparatus, and a relay board including a common terminal connected to the fuser connector. The relay board is connected to the temperature sensor and the state detection sensor and is configured to transmit respective signals output from the temperature sensor and the state detection sensor to the image forming apparatus via the common terminal.