DE60120328T2 - Sheet turning system - Google Patents

Description

technical area

There are copiers or printers with two sheet reversers in a printer / finisher system known in which one inverter is in the duplex loop path and the other inverter is in the finisher input or output path of the copier or printer. Called for example 3 US-A-5 697 040, which shows a xerographic printer, having both a duplex-away-sheet turning device and an output-path-sheet turning device. US-A-5,568,246 combines in series two different printing systems in a so-called dual machine printing system. As a result, the individual turning devices of each printing press together provide two turning devices, but these are in two separate printing presses. Other examples are disclosed in US-A-4,986,529 and US-A-5,131,659.

Further according to the state of technology often, due to the arrangement of the interfaces between the Turn / duplex loop and the remainder of the paper path in many printers the paper turning speed, the duplex loop speed and the output speed of the printer will be much higher as the processing speed. This is difficult and marginal conditions to be adhered to the sheet drive, the registration subsystems Etc.

As the expert knows may be the term "processing speed" in some contexts on the sheet speed in relation to the printing rate of the system Respectively. For example, in xerographic systems, the processing speed the speed at which the image substrate sheet is fed to and image transfer will be at the transmission station engaged with the photoreceptor belt or the photoreceptor drum, which) runs at processing speed. In general it is he wishes, that it is possible is, most of the rest of the paper ways of the reproduction device run at substantially the same processing speed allow. On the other hand, a sheet acceleration or deceleration is on the leaf velocity transition zones the paper paths required and distance problem between subsequent Scroll can arise. In particular, the blade acceleration can slip or other problems are caused on the friction drive wheel or belt system, which is typically for to guide the leaf in reproduction devices (printer or copier) is used. As is well known in the art, there is a "handoff" problem in the transition between a sheet feeding or feeding operation at a speed and the next or downstream sheet transport. Other sheet tax or registration matters can occur next to the slip, as a sudden pimple solution of the upstream feed system or other losses of accurate leaf position control transition problems. Anyway, the term processing speed "as used here Unless otherwise specified, speed may continue of leaves which move in certain paper paths, with which the dual-turn devices are functionally connected. Especially for example, as it is known, printer output paths and / or duplex paths with a higher one Sheet transport speed as the sheet speed at the Image transfer to run.

In many large volume Printer architectures that are used today requires the sheet reversal system that leaves all turned be accelerated quickly by the processing speed to a much higher one Turning speed when they get into the turning device. This means, to a very short distance from a processing or other Speed at about twice the processing speed to be accelerated to move in the turning device. this usually follows a sudden delay of the sheet in the turning device of the higher speed and then a re-acceleration to the higher speed to exit the turning device. additionally this leads to the difficulties described above also to a more critical leaf timing and registry issues.

US-A-4579446 discloses a sheet turning system in which sheets from a recording unit in a reversing unit with upper and lower reversing guides, in the alternate leaves alternately fed be fed become.

In accordance with the present invention, a sheet reversing system includes a double-turn system operatively connected to a sheet path on which closely spaced, printed sheets are transported in operation, the double-turn system having two independent but cooperating alternating sheet reversers and one sheet registration Control system, the sheet registration control system may be programmed and operated to alternately guide the closely spaced printed sheets on the sheet path to the alternate independent sheet inverters, and is characterized in that the two independent but cooperating alternating sheet inverters along the sheet path are arranged in front of and behind each other and can be operated in series with the sheet path that alternate leaves overtake each other by a first sheet on the sheet path in the front turning device is transported and the immediately following second sheet on the sheet path to the first sheet in the front turning device is conveyed past and into the rear turning device, and then the first sheet is transported past the second sheet in the rear turning device out of the front turning device, and then the second sheet in the rear turning device is transported on the sheet path.

In the embodiment disclosed here discloses an improvement in high-speed printing, which uses a combination of two cooperating sheet turning devices, around the overall productivity to improve the printing system. As is known, is an accurate Sheet turn coordination and / or compilation with the print sequence important for Duplexes (two-sided sheet printing), sheet output comparison, finishing and the same. The system disclosed herein avoids the typical, conventional approach, a much higher paper path (sheet feed) speed in a single turning device (which is twice as much the normal paper path or processing speed of the printer can be used), and so to maintain a compilation maintain a closer interleaf gap in the sheet path and to ensure that successively printed sheets do not stick together to disturb, act or impair even at high-speed printing with fast succession Scroll, moving in the paper paths.

One Advantage of the invention is that these have the possibility of a simplex or Non-turn-leaf path provides.

With The disclosed embodiment may be sequential leaves in the paper path are turned alternately by means of the two turning devices. Directly consecutive leaves have to not turned in the same turning device. Thus, can a turning mode with much lower speed used which offers many advantages. For example, with low speed turnarounds less power may be required, acoustic noise may be lower and system reliability including the reduced leaf stagnation rates can be improved. Also a subsequent sheet does not have to be for turning a previous one Leaf delayed be a sheet collision or a sheet collision to avoid or a falling out of leaves from a successive Paper order in pre-composed printing. Thus, that represents disclosed dual-turn system embodiment options for one improved high-speed pre-assembly print productivity, without the operating speeds and the blade reversal rates the leaves increased in the turning device and without causing an increase in the interleaf or spacing gaps between the leaves is required.

In addition exists a potential advantage in providing two inverters, which are suitable alternately the same function at the same Provide location of the base sheet path, wherein each of the sheet turning devices independently is working. If a turning system fails or is temporarily unusable Nevertheless, the entire reproduction system can still operate at a reduced processing speed continue to work without completely failing. For example, if a Papierstrau occurs in a turning device, the machine control determine these and automatically slow down the print rate to about half of Speed and exclusively the other available Use the turning device until the jam of the jammed turning device is fixed. The disclosed dual change-over device embodiments additionally potential benefits. For example, these may be conventional ones or use existing turning devices or turning device components or even duplicate. This means, that this system has two or any of various known or other types of sheet inverters. It can be used in different types of high-speed reproduction devices or finisher for that be incorporated with minor modifications.

Of course, the input and output path and locations of the dual inverters may be varied, depending on the desired application of the system and the reproduction apparatus, as further explained herein. For example, the arrangement and configuration of the dual-turn devices and their input and output paths may be different for applications in a sheet output or finisher system versus the use of the dual-turn system in a duplex loop return path for second side printing. In either case, dual inverters may optionally reside in a separate module module from the reproduction apparatus. The functions of both of the two sheet handling and turning applications are per se known to those skilled in the art and need not be discussed in detail here. For example, US Pat. Nos. 5,131,649 and 4,986,529, cited above, also show that a single inverter applies the two functions, the duplex pathway and / or the sheet dispensing is usable. (However, the presence of more than one sheet in a turner at the same time has other features and must avoid skip over of copy spacings, which reduces print rate productivity.)

As Also known in the art may be sheet turning devices even for Simplex printing (only one side is printed) in some situations will be used. For example for the turning of simplex leaves, the printed with the top side are in the order 1 to N (numbered in ascending order) so that these are side-down as correctly compiled sentences can be stacked. Or as an alternative you can Leaves, printed side-down (picture below), in the order N to 1 (numbered in descending order), for stacking turned upside down. In some systems, the an odd number of natural ones Having sheet path applications, a sheet turning device may even in a leaf way for an overprinting the same side of the sheet with a second color required be. That is, the Term "turning device" in the field can be far Various systems include avoiding turning a sheet as well as turning and / or reversing the leading edge to the trailing edge orientation of the blade over the entire leaf path.

One particular feature of the specific embodiment disclosed herein is, providing a high-speed reproduction device with a sheet path in which closely spaced apart, printed sheets down in the leaf path in an original Fed sheet sequence be, wherein the leaf path is a functional connection to a Sheet turning system according to the invention having, in the closely spaced, printed sheets supplied in the sheet path be turned to.

Further specific advantages disclosed herein in the embodiment individually or in combination, include those in which the closely spaced spaced-apart printed sheets at a processing speed supplied and both of the two independent but cooperative, alternating sheet turning facilities internal sheet feeding systems, those with the essentially same processing speed work, exhibit.

The two independent, but cooperative, alternating sheet turning facilities can opposite Be spaced sides of the sheet path.

The alternate sheet reversers may each independently operate Have Blatteingabetore, which separated from each other along the leaf path are spaced and the different by a Leaf gate control system are actuated, alternately alternating leaves to feed from the leaf path.

The Terms "reproduction device" or "printer" as used herein are widely different printers, copiers or multifunction machines or systems, xerographic or other, unless they are different defined in a claim. The term "sheet" here refers to a usually thin physical one Substrate made of paper or plastic or another suitable physical substrate for Pictures, pre-cut or web-fed. A "sheet copy" can be abbreviated as "copy" or "hardcopy". A "print job" is usually a sentence belonging together Leaves, usually One or more composed copy sets from a set original document sheets or electronic document page images is copied from one specific user or otherwise connected. A "simplex" document or a -Blattkopie is a sheet in which its image and any page number only on one side or surface of the Whereas a "duplex" document or a sheet copy has "pages", and normally Has images on both sides, that is each duplex sheet is called two opposite ones surfaces or having "pages" considered themselves if no physical page number exists.

Some Examples of high speed reproduction devices which Sheet turning systems according to the present invention The invention will now be described with reference to the accompanying drawings described in which:

1 Fig. 4 is a schematic front view of one embodiment of a cooperative dual-turn system according to the present invention showing a dual-turn system in a cooperative series configuration along a paper path of a reproduction apparatus;

2 . 3 and 4 the dual-turn system according to 1 in three successive operating positions for turning two successive sheets in the paper path,

5 schematically shows a comparative example of a dual-turn system in a parallel configuration, with turning means on opposite sides of the paper path with feed sheets from a single diverter,

6 Fig. 12 is a schematic front view of another example of a cooperative dual-turn system in a parallel configuration for double-sided printing of sheets;

7 a plan view of the example according to 6 which shows the paper path of which it is a part and since the turning decision gate for selecting which sheet enters the turning means, and Figs

8th is a schematic front view showing the dual-turn system according to 6 and 7 Fig. 10 shows integrated with an example of a printer constituting the turn portion of a duplex loop path for turning sheets to print on these second pages in the reproduction apparatus.

In Referring to the figures it can be seen that, although an embodiment and various examples are presented, these are many of the basic concepts and advantages described in the above introduction, have in common. These all provide dual turnarounds which are cooperatively operated alternately to alternate leaves from a sequential stream of leaves in a paper path supplied to turn. Because reasons and benefits to do so, in the previous introduction already explained have to these will not be repeated here.

In High-speed reproduction devices in which closely spaced, printed sheets sequentially downwards in a sheet path at a processing speed a dual-turn system with two independent but cooperative ones Sheet turning devices steered by a sheet control to alternately leaves the paper path for turning in the alternate independent sheet turning devices to recieve. These dual, alternating sheet reversers can advantageously with the substantially same blade speed like the compound blade path instead of at a much higher speed and acceleration / deceleration, which is typical for a conventional single inverter system. Thus, the original obtained assembled sheet order. The two independent, but are cooperative, alternating sheet reversers functionally connected in series and spaced along the sheet web, alternately with alternate leaves from the leaf path separate gates to be supplied and the leaves to the same leaf path due in different places.

Referring now to the embodiment of 1 - 4 1, it can be seen that the same dual-turn structure is shown from the same viewpoint in all of the four figures. Some details of the dual-turn system 30 of the 1 - 4 may be conventional and / or similar to those of the dual-turn system 10 of the 6 - 8th which will be described below, and thus need not be described in detail here. The two turning devices 33A . 33B this dual-turn system 30 may desirably be of conventional type. In this example, these are so-called "three-roll turning devices" with two pressure rollers, one for picking up incoming sheets, and one for returning (turning out) the turned sheets 33A . 33B have corresponding conventional three-roles 36A . 36B and reversing shaft reversing rollers 37A . 37B in curved turning shafts 38A . 38B , It can be seen that every individual turning device 33A or 33B this dual-turn system 30 Leaves from the paper 34 initiates ( 35A . 35B ) and the turned sheets after their turning back in a known and conventional manner to the same paper path (sheet path) but with different timing and control as will be described. Both turning devices 33A . 33B are here on the same page of the paper path 34 arranged, which may be desirable for reasons of a vertical workspace.

2 . 3 and 4 show an example of the sequential operation of this dual-turn system 30 for two consecutive leaves that descend into the leaf path 34 were fed, a first sheet 31 and a second sheet 32 , 2 shows the first sheet 31 , which deflected into the first turning device 33A is while the second leaf 32 passed this past. In 3 is the second leaf 32 deflected in the second turning device 33B while the first sheet has been turned and stands in front of the first turning device 33A to be issued. 4 shows that leaf one ( 31 ) now in the paper path 34 was issued and behind the second turning device 33B fed and that sheet two ( 32 ) in front of it, from the second turning device 33B in the paper path 34 to be issued, directly behind sheet one. The entrance gates 35A . 35B this turning facilities 33A and 33B may otherwise be similar to the decision gates described below 14A . 14B according to the example of 6 - 8th operate.

In the above-described working method illustrated for this dual-turn system 30 , two consecutive leaves effectively overtake each other as they pass through and into and out of the two turning devices 33A . 33B to run. In other words, if one runs first leaf 31 in the first turning device 33A is turned, the next following or second sheet 32 further along a bypass path between the two turning means (which here by a short connecting part of the paper path 34 is provided) and thereby moves in front of the first sheet 31 , Then the second sheet arrives 32 in the second turning device 33B and, while this is turned over, the first leaf bypasses 31 the second turning device 33B to move in front of the second sheet, and to move back into the correctly arranged sheet order. Any such two-leaf combination (an adjacent pair of leaves) may follow this same sequence. This allows the finished sheet order and inter-sheet gap to be the same as the initial inter-sheet gap and sheet order in the paper path 34 ,

It is of course obvious that when a mixed job with simplex sheets following a duplex sheet is present, then the operation is the same as for a conventional single-turn system. That is, it may require a skip distance in front of the simplex sheet, which passes directly through the paper path 34 is fed without turning.

In relation to now 5 , this is a comparative example of a dual-turn system 40 in which two turning devices 44A . 44B are parallel to each other and to the paper path and are arranged on opposite sides of the paper path. An ordinary leaf input path 41 and an ordinary leaf exit route 42 are in line with each other. In this dual-turn system 40 the leaves all arrive on the usual entrance way 41 in and out on the ordinary exit route 42 , From the conventional entrance way 41 The sheets can pass through a single inverter decision gate 43 in either the upper turning device 44A or a lower turning device 44B be redirected, the corresponding turning shafts 45A . 45B exhibit. Note that these are similar conventional three-roller type turning devices with reversing rollers in the inverter shafts. However, in this case, each turning device has 44A . 44B a parallel output path 46A . 46B from the inverter shaft and its three-roller output to a collection position in the conventional exit path 42 leads. A single Wendeleittor 43 alternately directs each other sheet to the alternate turning devices 44A or 44B to provide for the alternating leaves a turning passage between the entrance way 41 and the exit route 42 , For simplex printing (not turned), additional decision gates and a bypass path may be provided, as indicated by dashed lines 47A . 47B shown. Alternatively, the Wendeleittor 43 as shown, have a three-way gate and have a central position, which is the feeding of Simplexblättern through the gate 43 just by from the conventional entrance way 41 to the common starting point 42 allowing, eliminating any need for bypass gates and paths 47A . 47B eliminated. This alternative simplex way is in 5 represented by the phantom line paper path, which directly the common input path 41 with the common exit route through the gate 43 connects, everything in a common plane.

6 - 8th show another specific comparative example and the following or previous descriptions regarding the gate control functions, sensors, etc., can also be applied to the embodiment and need not be repeated.

Regarding the 6 . 7 and 8th and in particular to the enlarged view according to 6 , there is a dual-turn system 10 shown, consisting of two adjacent, parallel turning devices 12A and 12B , Both of the turning devices 12A and 12B have their sheet entrances with the same paper path 13 connected at adjacent but spaced apart positions. The connection of the turning devices with the paper path 13 is in this case (its sheet input) correspondingly through its two corresponding turning decision gates 14A and 14B provided. When activated, these decision gates extend 14A or 14B in the paper path 13 to engage the leading edge of a selected sheet in the paper path 13 and directs the sheet into the corresponding inverter input path 15A or 15B the turning device 12A or 12B around. These and other operations may be under the programmed control of a conventional controller 100 in the connected printer 20 according to 8th or in a separate modular controller of the dual-turn system 10 itself, which may be a modular unit for the printer and / or part of the finisher module.

If the particular print job calls for or requires a leaf application, the decision gate may 14A and 14B alternately by means of the control device 100 between each alternate leaf in the leaf path 13 are operated to be so varied, successive sheets of paper on the way 13 move, in alternating turning facilities 12A or 12B bring to. As previously stated, the construction and operation of the two inverters 12A and 12B be identical and can be conventional. In this comparative example, a sheet is replaced by the Wendeeinrichtungseingangsweg 15A or 15B fed by conventional feed rollers at this point and it can be a jam sensor 101A . 101B to pass the traffic jam detection. This sensor 101A . 101B Optionally, it may also be a dual-mode sensor that sends a control signal to the bidirectional inverter motor for the reverse feed rollers 17A . 17B in the inverter shafts 16A . 16B , After the sheet continues full feeding from the leaf path 13 This continues putting in the feeder shafts 16A or 16B continued. In this case, far enough away from the trailing edge of the blade (depending on the length of the blade) around a one-way bypass port 18A . 18B which is provided in this particular inverter example. Then the reversing rollers 17A . 17B conversely, that is, reversely driven to the sheet out through the exit path 19A . 19B drive.

This disposable bypass gates 18A . 18B For example, non-operable gates such as a conductive lightweight spring steel or a plastic material may allow the paper to pass therethrough and then spring back to its normal shape, as is known in other document handling devices and other prior art systems. The bidirectional sensor 101A . 101B can in the inverter shaft 15A . 15B arranged to provide a two-function paper input and output sensor assembly. This may provide software algorithm signals to drive the bidirectional inverter motor for the reverse feed rollers 17A . 17B in opposite directions when the corresponding leading and trailing edges of the paper sheet are detected. These turning devices 12A or 12B can record automatic mixed print jobs, such as sheets that vary from sheet size to sheet size. It can be seen that these turning devices 12A or 12B this dual-turn system 10 Here, too, provide great leaf path radii that reduce the potential leaf jamming problems.

In some other applications these exit routes would 19A . 19B the original paper path 13 , connect again as shown in other examples here. However, as in 8th shown, run in this example, the output paths 19A . 19B into a common output path that forms part of another conventional duplex loop blade path 22 That is, the pages are turned back to their second page print in the printer 20 returns, together. The exemplary duplex loop sheet path 22 provides conventional second-side printing of the sheets which are duplexed before being fed out of the output sheet path 24 of the printer 20 ready. Of course, sheets that are only simplex printed, not turned and through this Duplexschleifenweg 22 be supplied. These can go directly to the leaf delivery path 24 run, as is known in the art. In this case, they desirably pass linearly through the paper path 13 ,

For either duplex or simplex printing, these sheets are conventionally printed in this particular printer 20 for example, by moving these sheets behind a transfer station 25 to take pictures from a photoreceptor 26 be transferred. Of course, a comparable printing station can be provided by an ink jet or other printing system that is equally suitable for high speed printing. The unprinted pages for initial page printing may be conventionally provided by a rollfeed or cut sheet feed source (as shown) as is known in the art and need not be described here. The printer 20 Here is just one example of a high-speed xerographic digital laser printer, others cited above, which can quickly print on sheets in an accurate, sequential assembled order, that is, pre-assembled, thereby enabling direct on-line production of print jobs on compiled document sets and wherein an output sorter or assembler is not required.

It should be noted that in this particular comparative example the 6 - 8th the paper path 13 which is described above as a continuation of the output sheet path 24 of the printer 20 may be viewed in a separate module which may also provide an additional sheet feed source and / or provide an insert module for inserting additional preprinted media into the sheet feed stream of the paper path 13 , The paper path 13 may typically extend to one or more different finishing devices, as well known in the art. The location (s) of the subject dual-turn facilities may be different in these units.

It is obvious that the signals to actuate the corresponding inverter or decision gates 14A . 14B for positions of the sheet leading edges of the sheet timing and the positioning signals, which are already conventional in the control device 100 of the printer 20 are available, can be assigned. In an efficient variable-gap pressure for variable blade sizes, the timing and spacing between the leading edges of each other will be similar of course, depending on the length of the sheet in the process direction, within a given print job, so as to minimize unnecessary spacing and inter-document spacing between the various sheets being printed.

As described above, all of the sheet transporting means in the turning means can be used 12A and 12B if necessary, at the same or substantially the same steady-state sheet feeding speed as the sheet transporting means of the paper paths 13 with which it is connected. This processing speed may or may not be the same as the image processing speed of the printer 20 , As described above, this blade handling presents a significant advantage, without a collision between the closely adjacent blades, by means of the printer 20 be printed, risking. In particular, one no longer has to move the sheets through the reversing devices for the sheet reversing process so quickly, and thus one can also reduce the sheet acceleration or deceleration problems. Consequently, no undesirable overlapping of sheets in the turning system is required, and a positive sheet feeding control can be obtained at all times. Thus, increased throughput can be provided for high speed printing, now with increased reliability.

Claims (5)

Sheet turning system ( 30 ), which comprises a double-turn system that is functional with a sheet path ( 34 on which closely spaced-apart printed sheets are functionally transported, the double-throw system having two independent but cooperating alternating sheet reversers (US Pat. 33A . 33B ) and a sheet registration control system ( 35A . 35B ), the sheet registration control system can be programmed and operated to accommodate the closely spaced printed sheets on the sheet path (FIG. 34 ) alternately in the alternate independent sheet reversers ( 33A . 33B ), characterized in that the two independent but cooperating alternating sheet reversers ( 33A . 33B ) along the leaf path ( 34 ) are arranged in front of and behind each other and can be operated in series with the sheet path, so that alternate sheets overtake each other by a first sheet on the sheet path ( 34 ) in the front turning device ( 33A ) and the immediately following second sheet on the sheet path past the first sheet in the front turning device and into the rear turning device ( 33B ) and then the first sheet on the second sheet in the rear turning device ( 33B ) passing out of the front turning device ( 33A ) and then the second sheet in the front turning device ( 33B ) is transported on the sheet path. A system according to claim 1, wherein the two independent but cooperating alternate sheet reversers ( 33A . 33B ) have corresponding leaf exits which at different positions with one and the same leaf path ( 34 ) are connected. High-speed duplicating device which uses a sheet path ( 34 ) on which printed sheets spaced closely adjacent to one another are transported downstream on the sheet path, the sheet path having a functional connection to a sheet turning system ( 30 ) according to one of the preceding claims, in which the closely spaced printed sheets are transported on the sheet path for turning. A high-speed duplicating apparatus according to claim 3, wherein the closely spaced printed sheets on the sheet path ( 34 ) are conveyed at a process speed, and wherein both independent but cooperating alternate sheet reversers ( 33A . 33B ) have internal sheet transport systems that operate at substantially the same process speed. A high-speed duplicating apparatus according to claim 3 or claim 4, wherein the high-speed duplicating apparatus has a duplex loop path for returning one-side printed sheets to print on the other side thereof, and wherein the two independent but cooperating alternating sheet reversers ( 33A . 33B ) are alternately connected to form part of the duplex loop path.