An image forming apparatus includes an image forming device that forms an image on a recording medium and circuitry that controls the image forming device. The image forming device forms an invisible image with an invisible material on the recording medium and forms a visible image with a visible material on the invisible image. Each of first and second adhesion amounts includes respective adhesion amounts of the visible material and the invisible material per unit area in a portion, in which the visible image is formed on the invisible image, of the composite image. The second adhesion amount is smaller than the first adhesion amount. The controller adjusts the amount of the invisible material included in the second adhesion amount to be smaller than that included in the first adhesion amount, to cause the image forming device to form the image according to the second adhesion amount.

An image forming apparatus includes a first image forming portion, a second image forming portion, a belt, a charging voltage applying portion, and a transfer voltage applying portion. With respect to a movement direction of a recording material, the first image forming portion is provided upstream of the second image forming portion. In an image forming operation, a potential difference between a first transfer voltage and a potential at a first transfer portion, which is formed on a first image bearing member and does not form the image, is greater than a potential difference between a second transfer voltage and a potential at a second transfer portion, which is formed on a second image bearing member and does not form an image.

An image forming apparatus includes a first image forming portion, a second image forming portion, a belt, a charging voltage applying portion, and a transfer voltage applying portion. With respect to a movement direction of a recording material, the first image forming portion is provided upstream of the second image forming portion. In an image forming operation, a potential difference between a first transfer voltage and a potential at a first transfer portion, which is formed on a first image bearing member and does not form the image, is greater than a potential difference between a second transfer voltage and a potential at a second transfer portion, which is formed on a second image bearing member and does not form an image.

An image forming apparatus includes a revolving member, a transfer member, a guide member, and a controller. The revolving member revolves and retains a toner image on a peripheral surface thereof. The transfer member nips a transported recording medium and the revolving member at a nipping section and transfers the toner image retained by the revolving member onto the recording medium by receiving a voltage. The guide member is connected to ground, guides the recording medium to the nipping section, and is in contact with the recording medium nipped at the nipping section. The controller performs constant current control to transfer the toner image onto the recording medium if a print resistance is lower than or equal to a system resistance. The print resistance corresponds to when the voltage is applied to the transfer member in a state where the recording medium is nipped at the nipping section. The system resistance corresponds to when the voltage is applied to the transfer member in a state where the recording medium is not nipped at the nipping section.

A device includes an at least partially electrically conductive transfer member to travel along a travel path and a first portion along the travel path to receive an image-receiving holder onto the transfer member. A second portion is downstream from the first portion along the travel path to receive ink particles onto the image-receiving holder to form an image, while a transfer station is to transfer the ink particles and the image-receiving holder together from the transfer member to an image formation medium. A discharge element, which is interposed between the transfer station and the first portion, is to cause discharge of the transfer member.

An image forming apparatus includes an image forming portion, a high-voltage generation circuit, a current detection portion and a control portion. The image forming portion includes an image carrying member, a charging device, an exposure device and a developing device which includes a developer carrying member for carrying a two-component developer. The control portion can perform a transfer memory prediction mode that includes a step of estimating, when a first reference image is formed, the level of occurrence of transfer memory based on the direct-current component of a development current flowing through the developer carrying member and a step of measuring, when the measured direct-current component of the development current is larger than a predetermined value, the amount of charge of the toner within the developing device and estimating the cause of occurrence of the transfer memory based on the measured amount of charge of the toner.

A control circuit executes voltage adjustment processing of adjusting a voltage output from a transfer power source so that ae current detected by a detection circuit becomes a predetermined current value. The voltage adjustment processing is executed before a toner image is transferred from at least one of a first image bearing member and a second image bearing member to an intermediate transfer belt. A processor determines whether the second transfer member is in a state of contact or is in a state of separation on the basis of behavior of the current detected by the detection circuit in a period in which the control circuit is executing the voltage adjustment processing.

An image forming apparatus includes a detection unit and a control unit. The control unit controls a photoreceptor application unit and a development application unit such that a surface potential of a photoreceptor, which is applied by a photoreceptor application unit, is temporarily lower than a development potential which is applied by a development application unit and controls the photoreceptor application unit or the development application unit based on an adhesion amount of the developer, which is detected by the detection unit.

An image forming apparatus includes a revolving member, a transfer member, a guide member, and a controller. The revolving member revolves and retains a toner image on a peripheral surface thereof. The transfer member nips a transported recording medium and the revolving member at a nipping section and transfers the toner image retained by the revolving member onto the recording medium by receiving a voltage. The guide member is connected to ground, guides the recording medium to the nipping section, and is in contact with the recording medium nipped at the nipping section. The controller performs constant current control to transfer the toner image onto the recording medium if a print resistance is lower than or equal to a system resistance. The print resistance corresponds to when the voltage is applied to the transfer member in a state where the recording medium is nipped at the nipping section. The system resistance corresponds to when the voltage is applied to the transfer member in a state where the recording medium is not nipped at the nipping section.

An image forming apparatus includes an image forming portion, a high-voltage generation circuit, a current detection portion and a control portion. The image forming portion includes an image carrying member, a charging device, an exposure device and a developing device which includes a developer carrying member for carrying a two-component developer. The control portion can perform a transfer memory prediction mode that includes a step of estimating, when a first reference image is formed, the level of occurrence of transfer memory based on the direct-current component of a development current flowing through the developer carrying member and a step of measuring, when the measured direct-current component of the development current is larger than a predetermined value, the amount of charge of the toner within the developing device and estimating the cause of occurrence of the transfer memory based on the measured amount of charge of the toner.