Sheet feeding or delivering – Feeding – Separators
Reexamination Certificate
1998-06-22
2001-11-13
Skaggs, H. Grant (Department: 3651)
Sheet feeding or delivering
Feeding
Separators
C271S248000
Reexamination Certificate
active
06315282
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to media handling in printing devices. In particular, it relates to an apparatus and a method, capable of handling multiple media sizes, for picking a media sheet from a stack substantially squared to a media path and substantially eliminating the pick skew of the media sheet in the media path.
BACKGROUND OF THE INVENTION
Many different kinds of hardcopy printing devices are available commercially today, and these include copiers, faxes and printers. Ubiquitous hardcopy printing devices such as printers are commonly found in homes and offices. Since the evolution of office automation, printers have been integrally connected with other office automation equipment like computers, workstations, print servers, or networks to provide hardcopy printing capability. With the advent of increased CPU processing speed and power due to fast-paced technological advancement, better computers, workstations and servers have also come into being. Thus, that complementing equipment such as printers too must have increased throughput in order to contribute to the overall productivity of any office automation system is inevitable.
Printers commonly use printing paper of various sizes, transparencies, or even postcards as print media. These media sheets are fed sequentially into these printers to receive print markings. In doing so, the throughput of the printer is thus limited, in part, by the rate at which the printer receives the media sheets. Many known methods are currently implemented in commercially available printers to handle and provide media sheets efficiently to these printers for printing.
An example of the implementation of such known methods is the pick-and-feed operation of many ink jet printers. A pick operation entails picking a single media sheet from a stack of media sheets and moving it along a media path through the use of a pick roller. A drive roller and a pinch roller, which cooperate to perform a feed operation, controls the positioning of the media sheet with respect to a printing head for receiving print markings. In some ink jet printers, the pick-and-feed operation is performed by the same roller serving both the pick and drive functions for cost reasons. From the perspective of performance however, a pick roller would require a different type of material from that of a driver roller. For high pick reliability, the pick roller should be made of soft rubber with high friction coefficient. Conversely, the rubber used for the drive roller should be hard so that it does not deform easily and thus is able to control the feeding of the media sheet accurately. Therefore the implementation of a common roller to perform both operations may not meet the need for both reliable and accurate media handling.
Some ink jet printers, on the other hand, make use of separate pick and drive rollers to achieve reliable and accurate media handling. This type of implementation, however, can present its own set of problems, especially during the design of a pick system for resiliently handling various sizes of media sheets. This set of problems can exist because such a pick system for multiple sized media sheets is usually susceptible to the occurrence of pick skew of the different sizes of media sheets. If the media sheet is skewed, then the print markings received on the media sheet will not be square to the page and the result will be aesthetically displeasing.
The present invention is intended to provide a solution to various prior art deficiencies, which include those present with the existing printing devices such as copiers, faxes or printers, to provide a cost effective and reliable media sheet pick operation within a media handling system.
SUMMARY OF THE INVENTION
In a preferred embodiment, the present invention provides an apparatus, capable of handling multiple media sizes, for picking a media sheet from a stack substantially squared to a media path and substantially eliminating the pick skew of the media sheet in the media path. The apparatus comprises a rotating pick roller, and the pick roller rotates in an axis substantially orthogonal to the media path. The apparatus also comprises a separator which is raised from the surface of the media path. Accordingly, the rotating pick roller and the separator cooperate to provide parallel and opposing forces to separate the media sheet from the stack and move the media sheet along the media path. The apparatus further comprises a novel series of raised leveling surfaces on the surface of the media path. The leveling surfaces help to eliminate the pick skew by raising and leveling the leading edge of the media sheet.
The present invention also provides a method, capable of handling multiple media sizes, for picking a media sheet from a stack squared to a media path and the elimination of the pick skew of the media sheet in the media path. The method comprises the step of cooperatively using the pick roller and separator to apply parallel and opposing forces to separate the media sheet from a stack. The method also comprises the step of leveling the leading edge of the media sheet to eliminate the pick skew.
REFERENCES:
patent: 5004217 (1991-04-01), Kano et al.
patent: 5292117 (1994-03-01), Takagi et al.
patent: 5857671 (1999-01-01), Kato
patent: 5884908 (1999-03-01), Kato
patent: 0171734 (1988-07-01), None
patent: 403267228 (1991-11-01), None
patent: 405201570 (1993-08-01), None
patent: 406144620 (1994-05-01), None
patent: 406179540 (1994-06-01), None
Chua Ching Yong
Huang Pui Wen
Tee Ah Chong Johnny
Wu Seng Lim Richard
Hewlett--Packard Company
Skaggs H. Grant
LandOfFree
Apparatus and a method for picking multiple-sized media sheets does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and a method for picking multiple-sized media sheets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and a method for picking multiple-sized media sheets will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2592998