| 主权项 |
1. An alignment assembly for aligning a media sheet to a media feed path in an imaging device, the alignment assembly comprising:
a first and a second media guide spaced apart from each other along the media path allowing a media sheet to pass therebetween, the first and second media guides having opposed first and second media guide surfaces, respectively, forming a bubble chamber therebetween; the bubble chamber having an entrance having a predetermined width W1 and an exit having a predetermined width W2 positioned downstream of the entrance in a media process direction; a first and a second media feed roll pair positioned upstream of the entrance to the bubble chamber along respective first and second input portions of the media path and positioned immediately adjacent to the entrance of the bubble chamber, the first and second media feed roll pairs forming a first and a second feed nip positioned within the width W1 of the entrance, respectively, separated from one another by a distance D that is equal to or less than the width W1, allowing a media sheet travelling along each of the first input portion and the second input portion of the media path and received at the respective first and second feed nip to be fed directly into the entrance of the bubble chamber and toward the exit thereof; and, a bump alignment roll pair positioned along the media path downstream of and adjacent to the exit of the bubble chamber and forming a bump align nip adjacent to the exit for receiving the leading edge of the received media sheet, wherein, as the received media sheet is fed from one of the first and the second feed nips directly into the bubble chamber and into contact with the bump align nip, one of the first and the second media guide surfaces contacts and buckles a portion of the received media sheet disposed inside the bubble chamber forming a bubble in the portion of the media sheet within the bubble chamber allowing the leading edge of the received media sheet to be aligned with the bump align nip; and, further wherein, the first media guide surface has an entry surface, an exit surface, and a biasing surface connecting the entry and exit surfaces, the biasing surface positioned approximately midway between the bump alignment roll pair and the two media feed roll pairs, the entry surface being substantially planar and forming an obtuse angle with a centerline of the bump align nip for directing a media sheet being fed from the first media feed roll pair toward the second media guide surface, the exit surface having a substantially planar convex shape facing the second guide surface so that a leading edge of a media sheet being fed from the second media feed roll pair strikes the exit surface at an acute angle, the exit surface forming a generally obtuse angle with the centerline of the bump align nip, and the biasing portion biasing the media sheet, when buckling, away from the first media guide surface and into the bubble chamber. |
