Sheet feeding or delivering – Feeding – Separator and conveyor
Reexamination Certificate
1999-11-09
2001-08-28
Skaggs, H. Grant (Department: 3651)
Sheet feeding or delivering
Feeding
Separator and conveyor
C271S010110, C271S116000, C271S171000, C271S122000, C271S167000, C271S270000
Reexamination Certificate
active
06279893
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an automatic sheet feeder for a printer, facsimile apparatus or similar image forming apparatus or a scanner for automatically feeding sheets stacked on a tray to a reading section one by one.
In a conventional sheet feeder for the above application, a sheet feeding mechanism and a pickup roller raising and lowering mechanism are arranged at the center of a sheet of maximum size in the widthwise direction. It is therefore necessary to position two side guides at the same distance from the above center, a rack mechanism for causing the side guides to move in interlocked relation to each other, etc. This makes the various mechanisms sophisticated and thereby increases the cost of the sheet feeder. Further, a feed roller shaft and separation roller frame shaft each are required to have a length corresponding to the distance between the outer edge of a sheet of maximum side and a point around the center of the same sheet in the widthwise direction. Such shafts increase the overall weight of the sheet feeder.
Moreover, the side guides for preventing sheet from skewing must be moved in matching relation to the width of the sheet of maximum size. It follows that when the sheets of different sizes are stacked on the tray together, the sheets of smaller sizes are not regulated in width by the side guides at all. Such sheets not only skew, but also degrade reading quality and jam a conveyance path. Therefore, only the sheets of the same size must be selected and stacked on the tray.
Technologies relating to the present invention are disclose in Japanese Patent Laid-Open Publication Nos. 4-277150, 6-329303, 7-41191, 7-61616 and 9-216772 and Japanese Patent No. 2,636,085.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a light weight, low cost automatic sheet feeder allowing an image forming apparatus to sequentially read a stack of documents without degrading reading quality or causing paper jams ascribable to skew to occur even when the documents are of different sizes.
An automatic sheet feeder of the present invention includes a tray to be loaded with a stack of sheets, a side guide for preventing the sheets from skewing, and a sheet feeding mechanism for sequentially picking up and feeding the sheets, the top sheet being first. The tray includes an abutment parallel to a direction of sheet conveyance. The stack of sheets abut against the abutment at one side thereof. The side guide is movable toward and away from the abutment in matching relation to the size of the sheets. The sheet feeding mechanism is positioned at the intermediate between the abutment and the position of the side guide matching with sheets of minimum size available with the sheet feeder.
REFERENCES:
patent: 4113244 (1978-09-01), Ruenzi
patent: 4268021 (1981-05-01), Rutishauser et al.
patent: 4523832 (1985-06-01), Strutt et al.
patent: 5052676 (1991-10-01), Shina et al.
patent: 5648808 (1997-07-01), Yanagi et al.
patent: 5755435 (1998-05-01), Fujiwara
patent: 5971390 (1999-10-01), Caspar et al.
patent: 5975517 (1999-11-01), Lim
patent: 6059279 (2000-05-01), Wenthe
patent: 2359081 (1974-06-01), None
patent: 2816430 (1978-10-01), None
patent: 56-24750 (1954-07-01), None
patent: 58-188238 (1983-11-01), None
patent: 62-211254 (1987-09-01), None
patent: 63-60829 (1988-03-01), None
patent: 4-277150 (1992-10-01), None
patent: 6-329303 (1994-11-01), None
patent: 7-41191 (1995-02-01), None
patent: 7-61616 (1995-03-01), None
patent: 2636085 (1997-04-01), None
patent: 9-216772 (1997-08-01), None
patent: 10-120213 (1998-05-01), None
patent: 11-35174 (1999-02-01), None
Japanese Office Action issued Nov. 30, 1999 in a related application and English translation of relevant portions.
Japanese Office Action issued Mar. 28, 1999 in a related application and English translation of relevant portions.
Hatomi Keisuke
Ohkawa Kenichi
Takano Kohshi
NEC Corporation
Ostrolenk Faber Gerb & Soffen, LLP
Skaggs H. Grant
LandOfFree
Automatic sheet feeder for an image forming apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automatic sheet feeder for an image forming apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic sheet feeder for an image forming apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2550364