An image forming apparatus includes: a cover configured to be pivotal between a closed position and an open position to open an opening portion through which an intermediate transfer unit is removable, wherein when the cover is moved from an intermediate position to the open position, a secondary transfer unit is changed by using a self-weight of the secondary transfer unit from a first relative position to a second relative position, and wherein when the cover is located in the open position and the intermediate transfer unit is supported in a first position by a guiding portion, a secondary transfer unit interferes with the intermediate transfer unit if located in the first relative position, but does not interfere with the intermediate transfer unit if located in the second relative position.

An image forming apparatus includes an image forming unit, a casing, a door, a connecting member, a guide member, and an operating portion. The operating portion moves, through an operation by a user when the door is at a first opened position, from a regulating position where the connecting member is regulated from moving from a first guide to a second guide, to an allowing position where the connecting member is allowed to move from the first guide to the second guide. When the operating portion is at the regulating position, the door is configured to be retained at the first opened position by engagement of the connecting member and the first guide. When the operating portion is at the allowing position, the door is configured to be retained at the second opened position by movement of the connecting member from the first guide to the second guide.

A toner supply device includes a pressing portion that presses a toner cartridge such that the toner cartridge is detached from a device body. The toner cartridge has an engaging portion. The device body has a guiding portion. The guiding portion has an upper guide groove that guides the engaging portion in an attachment operation of attaching the toner cartridge to the device body, and a lock portion provided at a position deviated from the upper guide groove in an innermost portion of the guiding portion. When the engaging portion moving in the upper guide groove along with the attachment operation reaches the innermost portion, the engaging portion is engaged with the lock portion by the pressing portion pressing back the toner cartridge, allowing the toner cartridge to be attached to the device body so as not to be detached therefrom.

An image forming apparatus includes a transfer unit to transfer a toner image onto a sheet, a fusing unit, a discharging unit to discharge the sheet passed through the fusing unit, a guide member having a through-hole at a conveying surface and provided downstream of the fusing unit and upstream of the discharging unit in a conveying direction of the sheet, and a Helmholtz resonator. The Helmholtz resonator includes a cavity portion and communicating portions through which the cavity portion is in communication with an outside area. The Helmholtz resonator and a conveying path of the sheet guided by the guide member are connected through the through-hole. The Helmholtz resonator is disposed on a downstream side with respect to the fusing unit and on an upstream side with respect to the discharging unit in the conveying direction of the sheet, and the communicating portion is disposed facing the guide member.

A printer includes a controller that operates an actuator of a transfer assist blade (TAB) mechanism with reference to an actuator profile. The actuator profile identifies an actuator waveform and a plurality of pulse trains for the actuator waveform. The actuator profile and the data associated with it are developed with reference to the drive train for the TAB mechanism. The actuator profiles enable the TAB mechanism drive train to achieve optimal operation over a wide range of media types, substrate speeds, pitch modes, and other print job parameters.

An image forming apparatus includes: a cover configured to be pivotal between a closed position and an open position to open an opening portion through which an intermediate transfer unit is removable, wherein when the cover is moved from an intermediate position to the open position, a secondary transfer unit is changed by using a self-weight of the secondary transfer unit from a first relative position to a second relative position, and wherein when the cover is located in the open position and the intermediate transfer unit is supported in a first position by a guiding portion, a secondary transfer unit interferes with the intermediate transfer unit if located in the first relative position, but does not interfere with the intermediate transfer unit if located in the second relative position.

Provided is an image forming apparatus wherein a transfer material transport guide 35 is disposed in an optical sensor unit 29 to support a color deviation sensor, which is disposed near an intermediate transfer belt 6. By changing the position of the optical sensor unit 29, the grounding path of the transfer material transport guide 35 can be changed, and both the transfer bias leak prevention for the transfer material transport guide 35 and the electrostatic breakdown prevention for the color deviation sensor can be implemented. As a result, the apparatus can be downsized, and only when the intermediate transfer belt is replaced, the optical sensor unit 29 can be moved to create a space necessary for the replacement.

An image forming apparatus includes an image former forming a toner image on a long sheet; a main conveyance path conveying the long sheet to the image former; and a double-side conveyance path which branches off from a first side, in the main conveyance path, downstream of the image former in a conveyance direction of the long sheet, and which conveys the long sheet to a second side upstream of the image former by reversing the conveyance direction at a point of switching back to invert the long sheet. The double-side conveyance path includes, in a downstream side in the conveyance direction before the switching back, a merging pathway connected to the second side upstream of the image former in the main conveyance path, and a first introducer introducing into the merging pathway a head of the long sheet in the conveyance direction before the switching back.

A transfer device includes a holding body that holds a toner image and to which a first tension and a second tension, which is smaller than the first tension, are applied, a transfer body that transfers the toner image to a recording medium while transporting the recording medium between the transfer body and the holding body, and a setting portion that sets tension applied to the holding body to the second tension when a mass of a toner of an uppermost toner layer constituting the toner image and disposed on the holding body is equal to or exceeds a threshold.

An image forming apparatus includes a plurality of image forming portions, an intermediate transfer belt, a primary transfer member, a secondary transfer roller, a counter roller, and a charge eliminating device. The counter roller is pressed against the secondary transfer roller via an intermediate transfer belt to thereby form a secondary transfer nip portion. The charge eliminating device includes a charge eliminating needle that is disposed with an end part thereof pointing to a downstream side in a conveyance direction of the recording medium, and that is grounded, and a charge eliminating needle protection cover that has a guide surface that is opposed to the recording medium having passed through the secondary transfer nip portion. The guide surface is formed of a conductive material having a resistance value of 10.sup.6? or lower, and is in a floating state.