Patent Application
20110291354
This invention relates to a sheet transport system and, more specifically, to a sheet transport system for handling different size media.
While the present invention can be used for any suitable system to handle different size sheets, for clarity, it will be described in relation to use in a xerographic marking apparatus. Any suitable media can be used such as sheet materials, papers, etc. The term “cards” will be used and intended to be inclusive of any sheet media of different lengths.
In an electrostatographic reproducing apparatus commonly used today, a photoconductive insulating member may be charged to a negative potential, thereafter exposed to a light image of an original document to be reproduced. The exposure discharges the photoconductive insulating surface in exposed or background areas and creates an electrostatic latent image on the member which corresponds to the image areas contained within the original document. Subsequently, the electrostatic latent image on the photoconductive insulating surface is made visible by developing the image with a developing powder referred to in the art as toner. During development, the toner particles are attracted from the carrier particles by the charge pattern of the image areas on the photoconductive insulating area to form a powder image on the photoconductive insulating area. This image may be subsequently transferred or marked onto a support surface such as copy paper to which it may be permanently affixed by heating or by the application of pressure. Following transfer of the toner image or marking, the copy paper may be removed from the system by a user or may be automatically forwarded to a finishing station where the copies may be collected, compiled and stapled and formed into books, pamphlets or other sets to be wrapped, etc.
As above noted, there are many marking systems that transport paper or other media after the paper is marked in marking step or steps. These marking systems could include electrostatic marking systems, non-electrostatic marking systems and printers or any other system where paper or other flexible media or receiving sheets are transported internally to an output device such as a finisher and compiler station or stations. These devices include those used for collecting or gathering printed sheets so they may be formed into sets such as books, pamphlets, forms, sales literature, instruction books and manuals and the like.
These electrostatic marking systems have finisher and compilers located at a site after the receiving sheets (paper) have been marked with a toner.
Multi-sheet collations when transported by a pusher belt system after marking either arrive to the belt unregistered are added unregistered to a pre-registered set or become unregistered during transport. Single and multi-sheet collations of different lengths are contained in the process direction by pushers but the length differences in the collations do not allow for side to side registration with fixed registration walls designed to accommodate the largest size. This causes misregistration in those stacks made up of any media with sizes smaller than the registration wall width dimensions.
A common problem encountered with pusher type transports is misregistration and skewing of the media stack. This misregistration is caused by three main problems:
By designing a belt that uses different height pushers 2 “bins” can be formed to contain different size media. A smaller bin within a larger bin made up of taller pushers creates a system that allows for the transport of different size media while significantly reducing the scatter that is caused by transporting media that is too small for the pusher spacing.
To ensure that the media is controlled during placement onto the belt and is collated in the proper bin, an actuator is used to act as a diverter guide or paddle. This creates a stop to drive the smaller sheets into the smaller bin and keeps the sheets from overshooting the pusher. This actuated guide or paddle is then moved up and out of the way of the tallest pushers so the belt can translate without interfering with the pushers. In this way, the actuator does not contact the pushers and damage the pushers. Once the pusher has translated past the diverter paddle, the paddle can be actuated back down to the pusher to provide a stop for the next incoming sheet. This is all controlled by the system based on feedback of what size and number of sheets are arriving. Additionally, when the diverter is not needed for larger sheets, it is brought up and out of the way for the larger sheets being fed into the bin.
As is common in transports, this system involves a high acceleration in the process direction which causes shingling and scatter to the cards within the sets. By allowing for different sized bins and the means (actuated diverter) to put the media into each depending on size, the system is now able to transport even the smallest cards without jamming due to the reduction of the shingling/scattering effects.
This invention uses two different height pushers spaced to accommodate different size media. These pushers are spaced to provide two bin sizes that allow for bucketing different sized media to reduce shingling and scatter during transport.
To place the media in the appropriate bin, a diverter gate paddle is used to divert the media into the appropriate bin size. To accommodate different sizes of media as well as different height pushers, the diverter gate paddle is actuated to lower into position to divert smaller media into the smaller bin and then the diverter gate paddle is actuated to raise the paddle above the taller pushers during transport. The actuation is controlled by the system based on a signal using sensors and a controller to identify media size and sheet count.
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To summarize, the present invention provides a media transport system for multiple size media transport comprising a bin transport belt having on its upper face a plurality of collection, smaller and larger, bins and pushers. The collection bins have on each terminal end tall pushers, and have at a point between the tall pushers a small pusher. An imaged media belt transport is located at a forward portion of the transport belt and is configured to deposit large and small marked media (or cards) in the collection bins. Positioned above the collection bins and in feeding relationship to the card transport is an actuator with a diverter paddle.
When the diverter paddle is in a down position, the small cards are deflected off the paddle and fall into the smaller bins. When the diverter paddle is in an up position, the large cards are unblocked by the diverter paddle and fall into the larger bins.
At least one sensor and controller are located upstream of the imaged media transport belt. The sensors are configured to sense the size of the media and with communication with the controller raise or lower the diverter paddle to correspond to the size of the media. The actuator could be selected from the group consisting of air actuators, solenoid actuators and stepper motor actuators.
The larger bins are configured to receive and house the large marked media. The large marked media when housed rests upon the top of the small pusher. The media when in the smaller and larger bins are in substantial collated alignment. The imaged media belt transport is a vacuum belt transport configured to hold a media thereon until deposited into one of the bins.
In another embodiment, this invention provides a media transport system for multiple size media transport comprising a bin transport belt having on its upper face a plurality of smaller and larger collection bins and pushers. The collection bins have on each terminal end tall pushers and have at a point between the tall pushers a small pusher. An imaged media belt transport is located at a forward portion of the transport belt and is configured to deposit large and small marked media (or cards) in the collection bins. Positioned above the collection bins and in feeding relationship to the card transport is an actuator with a diverter paddle. The bins are configured on the transport belt in a manner where every other pusher is a tall pusher and the remainder are short pushers. The bins, being of substantially uniform length throughout the bin transport belt and the bins are configured to hold either the small cards or the large cards in a substantially collated arrangement.
It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
