US Patent No. 10,114,329

IMAGE FORMING APPARATUS WHICH CONTROLS PERIOD BETWEEN TRAILING EDGE OF PRECEDING SHEET AND LEADING EDGE OF NEXT SHEET


Patent No. 10,114,329
Issue Date October 30, 2018
Title Image Forming Apparatus Which Controls Period Between Trailing Edge Of Preceding Sheet And Leading Edge Of Next Sheet
Inventorship Takuma Tadomi, Toride (JP)
Tatsuhito Watanabe, Tokyo (JP)
Assignee Canon Kabushiki Kaisha, Tokyo (JP)

Claim of US Patent No. 10,114,329

1. An image forming apparatus comprising:an image forming device configured to form an unfixed toner image on a sheet continuously conveyed;
a fixing device configured to fix the unfixed toner image formed by the image forming device on the sheet while conveying the sheet continuously conveyed from the image forming device, wherein the fixing device includes a first rotatable member of which a surface layer containing a fluororesin is brought into contact with a sheet surface having the unfixed toner image formed by the image forming device and a second rotatable member configured to form a nip portion in cooperation with the first rotatable member;
a receiving unit configured to receive, from an operator, an instruction of a mode to be executed among a plurality of modes including a first mode and a second mode; and
a controller configured to control conveyance of a sheet, according to the mode corresponding to the instruction received by the receiving unit,
wherein, in a case that the mode corresponding to the instruction received by the receiving unit is the first mode and image formation processing for continuously forming a toner image on a plurality of predetermined sheets is executed, the controller controls the conveyance of the sheet in the image formation processing so that a period from when a trailing edge of a preceding sheet passes through the nip portion till a leading edge of a next sheet reaches the nip portion is a first period, wherein, in the first period, a portion of the surface layer of the first rotatable member, which is brought into contact with the trailing edge of the preceding sheet, is brought into contact with an image area on the next sheet without being contact with a margin area on a leading edge side on the next sheet, and
wherein, in a case that the mode corresponding to the instruction received by the receiving unit is the second mode and the image formation processing is executed, the controller controls the conveyance of the sheet so that the period is a second period longer than the first period, wherein, in the second period, the portion of the surface layer of the first rotatable member, which is brought into contact with the trailing edge of the preceding sheet, is brought into contact with the margin area on the leading edge side on the next sheet.