JP2016075800A5 - - Google Patents

Description

In order to achieve the above object, a typical configuration of an image forming apparatus according to the present invention includes an image forming unit that forms a toner image on a sheet, and a toner image formed on the sheet by the image forming unit in a nip unit. A heating rotator and a pressure rotator to be fixed, and an execution unit for executing a cleaning mode for cleaning the heating rotator by introducing a sheet on which a predetermined toner image is formed by the image forming unit into the nip portion. And the relative position of the first sheet and the second sheet with respect to the heating rotator in the width direction of the heating rotator when the first sheet and the second sheet are sequentially introduced into the nip portion in the cleaning mode. And a change mechanism for changing the relationship .

In the double-sided printing mode, the sheet P on which the first-side image has been formed exiting the fixing device 6 is introduced into the double-sided conveyance path (double-sided path unit : re-introducing mechanism ) 11 and turned upside down, and again toward the oblique feeding mechanism 2 Are transported. A toner image is transferred and formed on the second surface of the sheet P at the transfer nip T. The sheet P is re-introduced into the toner image formed on the second surface is fixed to the fixing device 6 again. The sheet P is discharged out of the apparatus as a double-sided image formed product.

At this time, the apparatus 1 forms an image so that the left and right margins are 2 mm so that the left and right margins in the width direction of the cleaning sheet Pc are minimized. That is, a toner image is formed over the entire area in the width direction in which an image can be formed on the sheet. The front and rear end margins in the conveyance direction of the cleaning sheet Pc may be arbitrary because they do not affect the cleaning effect, but in the mode of this embodiment, the margin is set to 10 mm.

The cleaning execution configuration of the fixing device 6 is summarized as follows. When the sheet is inserted into the nip portion at least twice in the cleaning mode (sequential introduction, introduction twice) , the relative positions of the first and second sheets relative to the fixing belt 130 in the width direction of the fixing belt 130 (relative positional relationship) ) Is changed.

Claims (8)

An image forming unit for forming a toner image on a sheet;
A heating rotator and a pressure rotator for fixing the toner image formed on the sheet by the image forming unit at the nip,
An execution unit that executes a cleaning mode for cleaning the heating rotator by introducing a sheet on which a predetermined toner image is formed by the image forming unit into the nip portion;
When the first sheet and the second sheet are sequentially introduced into the nip portion in the cleaning mode, the relative positional relationship between the first sheet and the second sheet with respect to the heating rotator in the width direction of the heating rotator is determined. A change mechanism to change,
An image forming apparatus comprising: The change mechanism includes a shift mechanism that shifts the position of the sheet in the width direction, and the shift mechanism changes the relative positional relationship by shifting the positions of the first sheet and the second sheet in the cleaning mode. The image forming apparatus according to claim 1, wherein: The change mechanism includes a shift mechanism that shifts the position of the heating rotator in the width direction, and the shift mechanism changes the relative positional relationship by shifting the position of the heating rotator in the cleaning mode. The image forming apparatus according to claim 1. The change mechanism includes a first shift mechanism that shifts the position of the sheet in the width direction, and a second shift mechanism that shifts the position of the heating rotator in the width direction. The image forming apparatus according to claim 1, wherein the relative positional relationship is changed by a shift mechanism and the second shift mechanism. A reintroduction mechanism that reverses the front and back of the sheet that has passed through the nip portion and reintroduces the sheet into the nip portion; and the change mechanism includes a first sheet and a second sheet that are reversed in the cleaning mode. 5. The image forming apparatus according to claim 1, wherein the relative positional relationship of the sheet with respect to the pressure rotator is changed. 6. The image forming apparatus according to claim 1, wherein the image forming unit forms a toner image as the predetermined toner image in an entire region in a width direction in which an image can be formed on a sheet. . An image forming unit for forming a toner image on a sheet;
A heating rotator and a pressure rotator for fixing the toner image formed on the sheet by the image forming unit at the nip,
An execution unit that executes a cleaning mode for cleaning the heating rotator by introducing a sheet on which a predetermined toner image is formed by the image forming unit into the nip portion;
A reintroduction mechanism that reverses the front and back of the sheet that has passed through the nip portion and reintroduces it into the nip portion;
When introducing one sheet into the nip portion twice using the reintroduction mechanism in the cleaning mode, the relative positional relationship between the first and second sheets with respect to the heating rotator in the width direction of the heating rotator A shift mechanism that shifts the position of the seat so that the
An image forming apparatus comprising: The image forming apparatus according to claim 7, wherein the image forming unit forms a toner image as a predetermined toner image in an entire region in a width direction in which an image can be formed on a sheet.