IMAGE FORMING APPARATUS

摘要

An image forming apparatus includes an image forming station; a heating roller and a pressing roller forming a fixing nip therebetween; a changing mechanism for changing a relative positional relation between the heating roller and the pressing rotatable member between a contacting position in which they are contacted, a first spacing position in which they are spaced, and the second spacing position in which they are spaced by a shorter distance; and a controller for the changing mechanism such that in a period after the sheet passes through the fixing nip and before a next sheet reaches the fixing nip, the relation is brought into the first spacing position when the period is longer than a first predetermined period, and that the relation is brought into the second spacing position when the period is shorter than the first predetermined period and is longer than a second predetermined period.

主权项

1. An image forming apparatus comprising:
an image forming station capable of continuously forming on a plurality of sheets; a rotatable heating member and a pressing rotatable member cooperative with each other to form a fixing nip configured to fix the images formed by the image forming station on the sheets; a changing mechanism for changing a relative positional relation between said rotatable heating member and said pressing rotatable member between a contacting position in which said rotatable heating member and said pressing rotatable member are contacted with each other, a first spacing position in which said rotatable heating member and said pressing rotatable member are spaced from each other, and the second spacing position in which said rotatable heating member and said pressing rotatable member are spaced from each other by a distance shorter than that in the first spacing position; and a controller for controlling said changing mechanism such that in a period after the sheet passes through the fixing nip and before a next sheet reaches the fixing nip, the positional relation is brought into the first spacing position when the period is longer than a first predetermined period, and that the positional relation is brought into the second spacing position when the period is shorter than the first predetermined period and is longer than a second predetermined period.