Abstract: An image forming system includes an image forming apparatus including an image forming unit and a fixing unit; a folding processing portion; a pressure-bonding portion; and an input portion capable of selecting a pressure-bonding mode in which a pressure-bonding print prepared by subjecting the recording material to pressure-bonding processing by the folding processing portion and the pressure-bonding portion and capable of selecting a layout of the toner image formed on the recording material. When the pressure-bonding mode is selected, the layout depending on the pressure-bonding mode is selected.

Abstract: An image forming system includes an image forming apparatus including a fixing unit, a folding processing portion, and a pressure-bonding portion. A first recording material having a first basis weight is fixed at a first temperature by the fixing unit and then is pressure-bonded by the pressure-bonding portion after a lapse of a first period. A second recording material having a second basis weight is fixed at a second temperature by the fixing unit and then is pressure-bonded by the pressure-bonding portion after a lapse of a second period. The second basis weight is larger than the first basis weight. The second temperature is higher than the first temperature. The second period is longer than the first period.

Abstract: An image forming system includes an image forming apparatus, a pressure sealing processing apparatus, and a control unit. The control unit is configured to permit execution of the pressure sealing processing process by the pressure sealing processing apparatus on a recording material of which a grammage is smaller than a predetermined grammage, and is configured not to permit execution of the pressure sealing processing process by the pressure sealing processing apparatus on a recording material of which a grammage is equal to or more than the predetermined grammage.

Abstract: An image forming system includes an image forming apparatus, a pressure sealing processing apparatus, and a control unit. The control unit is configured to permit execution of the pressure sealing processing process by the pressure sealing processing apparatus on a recording material of which a grammage is smaller than a predetermined grammage, and is configured not to permit execution of the pressure sealing processing process by the pressure sealing processing apparatus on a recording material of which a grammage is equal to or more than the predetermined grammage.

Abstract: An image forming apparatus includes an image bearing member, a transfer member forming a transfer portion, a transfer voltage applying device, a sensor, and a controller. The controller is capable of executing an operation in a first setting mode before a preparatory operation, and executes, in the preparatory operation, an operation in a second setting mode in which test voltages or test currents fewer in number of levels than those in the first setting mode are supplied to the transfer portion and in which a second voltage-current characteristic is acquired on the basis of a first voltage-current characteristic in the operation in the first setting mode and a detection result of the sensor detected during supply of the test voltages or the test currents, and then sets the transfer voltage on the basis of the second voltage-current characteristic.

Abstract: An image forming apparatus includes an image bearing member, a transfer member forming a transfer portion, a transfer voltage applying device, a sensor, and a controller. The controller is capable of executing an operation in a first setting mode before a preparatory operation, and executes, in the preparatory operation, an operation in a second setting mode in which test voltages or test currents smaller in number of levels than those in the first setting mode are supplied to the transfer portion and in which a second voltage-current characteristic is acquired on the basis of a first voltage-current characteristic in the operation in the first setting mode and a detection result of the sensor detected during supply of the test voltages or the test currents, and then sets the transfer voltage on the basis of the second voltage-current characteristic.

Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer belt, a primary transfer roller provided so that a contact region between the roller and the belt and a contact region between the image bearing member and the belt are in a non-overlapping state with each other with respect to a movement direction of the belt, a primary transfer voltage source, a current detecting portion, an executing portion configured to acquire information on a discharge start voltage on the basis of a detection result of the detecting portion in a period other than a period of primary transfer by applying the voltage to the roller and a setting portion configured to set, on the basis of an execution result of the executing portion, a primary transfer voltage applied to the roller by the primary transfer voltage source in the period of the primary transfer.

Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer belt, a primary transfer roller provided so that a contact region between the roller and the belt and a contact region between the image bearing member and the belt are in a non-overlapping state with each other with respect to a movement direction of the belt, a primary transfer voltage source, a current detecting portion, an executing portion configured to acquire information on a discharge start voltage on the basis of a detection result of the detecting portion in a period other than a period of primary transfer by applying the voltage to the roller; and a setting portion configured to set, on the basis of an execution result of the executing portion, a primary transfer voltage applied to the roller by the primary transfer voltage source in the period of the primary transfer.

Abstract: In an image forming apparatus including a power source for forming a secondary-transfer electric field at a secondary-transfer position and for forming a primary-transfer electric field at a primary-transfer position by applying a voltage to a transfer member to pass a current through a constant-voltage element, a potential of an image portion is controlled depending on a detection result of a detecting member.

Abstract: In a constitution in which a power source exclusively for primary-transfer is omitted and a predetermined voltage is generated in an intermediary transfer member, in a test mode in which a test voltage is applied to a secondary-transfer member in advance in order to obtain a proper secondary transfer voltage, in the case where the test voltage is low, a proper secondary-transfer voltage cannot be obtained in some cases. In a period of the test mode, the power source is controlled in order to maintain a Zener breakdown voltage, so that the proper secondary-transfer voltage can be obtained.

Abstract: In a constitution of primary-transfer-high-voltage-less in which a power source dedicated to primary-transfer, in the case where voltage applications for determining primary-transfer and secondary-transfer voltages are carried out concurrently, there is a possibility of improper primary-transfer. The possibility is decreased by controlling a power source so that a voltage drop of a Zener diode maintains a Zener breakdown voltage.

Abstract: The image forming apparatus has a control unit executing image forming by choosing either one of modes including first and second modes, the first mode for setting a length of an interval region between images in between a first region of an intermediate transfer member is formed and a second region of the intermediate transfer member is formed to a first length and the second mode for setting the same to a second length, and the control unit sets the first length to such a length that a region of the intermediate transfer member after one rotation of the first region and at least a part of the second region are overlapped with each other and the second length to a length of one rotation or more and two rotations or less of the intermediate transfer member.

Abstract: In an image forming apparatus including a power source for forming a secondary-transfer electric field at a secondary-transfer position and for forming a primary-transfer electric field at a primary-transfer position by applying a voltage to a transfer member to pass a current through a constant-voltage element, a potential of an image portion is controlled depending on a detection result of a detecting member.

Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer member, a plurality of stretching members, a transfer member, a constant-voltage element, a voltage source, an obtaining portion for obtaining information on an image ratio of a toner image formed on the image bearing member, a voltage controller for controlling the voltage source so that a first voltage is applied to the transfer member in a period in which primary transfer of the toner image is executed and secondary transfer of the toner image is not executed and so that a second voltage larger than the first voltage is applied to the transfer member in a period in which the secondary transfer of the toner image is executed, and an adjusting portion for adjusting the first voltage on the basis of the information obtained by the obtaining portion.

Abstract: In a constitution provided with no primary-transfer roller, in order to ensure a contact length between each of photosensitive drums and an intermediary transfer belt, the photosensitive drums are disposed with projecting amounts of a plurality of levels with respect to a stretching surface of the intermediary transfer belt, and therefore an apparatus is liable to be increased in a height direction. In order to avoid this, four image bearing members are arranged, along the intermediary transfer belt, with the same projection amount with respect to the stretching surface of the intermediary transfer belt, and a depressing member for depressing a belt surface between two central image bearing members toward an outside is provided.

Abstract: An image forming apparatus includes: an image bearing member; an electrostatic image forming unit; a developing unit; an intermediary transfer member; a rotatable secondary transfer member; a constant voltage element; a voltage source; and a controller. The apparatus is operable in a lowering mode in which a secondary transfer electric field in a trailing end region of a recording material passing through a secondary transfer position with respect to a recording material feeding direction is made lower than the secondary transfer electric field in a region from a leading end to the trailing end region of the recording material. The controller sets a toner image distance so as to be longer than the toner image distance when the operation in the lowering mode is not performed to prevent a toner image from being primary-transferred in a period in which the secondary transfer electric field is lowered.

Abstract: An image forming apparatus includes a photosensitive member, a charging member for electrically charging the photosensitive member to a first polarity, an intermediary transfer belt, a transfer member, a constant-voltage element, a voltage source, and a controller for executing an adjusting operation for applying at least a voltage of a second polarity, opposite to the first polarity from the voltage source to the transfer member during non-image formation in which both of primary transfer and secondary transfer are not effected. When the voltage of the second polarity is applied from the voltage source to the transfer member in the adjusting operation, the controller continuously applies the voltage for a time corresponding to a substantially integer multiple of a time required for one full turn of the photosensitive member.

Abstract: In an image forming apparatus including a power source for forming a secondary-transfer electric field at a secondary-transfer position and for forming a primary-transfer electric field at a primary-transfer position by applying a voltage to a transfer member to pass a current through a constant-voltage element, a potential of an image portion is controlled depending on a detection result of a detecting member.

Abstract: In a constitution in which a power source exclusively for primary-transfer is omitted and a predetermined voltage is generated in an intermediary transfer member, in a test mode in which a test voltage is applied to a secondary-transfer member in advance in order to obtain a proper secondary transfer voltage, in the case where the test voltage is low, a proper secondary-transfer voltage cannot be obtained in some cases. In a period of the test mode, the power source is controlled in order to maintain a Zener breakdown voltage, so that the proper secondary-transfer voltage can be obtained.

Abstract: In a constitution of primary-transfer-high-voltage-less in which a power source dedicated to primary-transfer, in the case where voltage applications for determining primary-transfer and secondary-transfer voltages are carried out concurrently, there is a possibility of improper primary-transfer. The possibility is decreased by controlling a power source so that a voltage drop of a Zener diode maintains a Zener breakdown voltage.