Patent ID: 8971756
Filing Date: 2015-03-03
Classification: G03G,H04N

Abstract:
1. An image forming apparatus for supporting a detachably mountable optional unit, comprising: an image forming portion, including a rotatable photosensitive member, for forming a toner image formed on the photosensitive member on a recording material; a frame for supporting said image forming portion, wherein said frame includes a first frame which is provided on a bottom of said image forming apparatus and which corresponds to a first side surface of said image forming apparatus and includes a second frame which is provided on the bottom of said image forming apparatus and which corresponds to a second side surface, opposing the first side surface, of said image forming apparatus; a first supporting portion and a second supporting portion, which are provided close to the first frame, for supporting said frame and in contact with a disposition surface, wherein a first rectilinear line connecting said first and second supporting portions is substantially parallel to a rotational axis of the photosensitive member; a third supporting portion for supporting said frame in contact with the disposition surface, wherein said third supporting portion is provided close to the second frame and in a neighborhood of a second rectilinear line which is perpendicular to the first rectilinear line connecting said first and second supporting portions and passes through a center of gravity of said image forming apparatus in a state in which the optional unit is not mounted; and an auxiliary leg adjustable between a height where it does not contact the disposition surface and a height where it contacts the disposition surface, wherein said auxiliary leg is provided close to the second frame, wherein when a position where the center of gravity of said image forming apparatus before the optional unit is mounted to said image forming apparatus is projected vertically onto an edge line of the second frame is a first position and a position where the center of gravity of said image forming apparatus after the optional unit is mounted to said image forming apparatus is projected vertically onto the edge line of the second frame is a second position, a direction from a position where said third supporting portion is projected vertically onto the edge line of the second frame toward a position where said auxiliary leg is projected vertically onto the edge line of the second frame is the same direction as a direction from the first position toward the second position.