Patent Application
20130004186
Currently, two or more printers (or “print engines”) are combined in a Tightly Integrated Serial Printing (TISP) system or a Tightly Integrated Parallel Printing (TIPP) system to provide a single print system of higher capacity and with other advantages. In such known systems, each printer is assigned a specific dedicated printing role. For example, a first printer of a TISP/TIPP printing system is assigned a first printing role of “side one printing” of pages and a second printer of the TISP/TIPP printing system is assigned a second printing role of “side two printing” of pages. Such dedication of printing roles provides advantages, but can also lead to problems. In particular, the first and second printers often migrate to different overall states of relative print quality, performance, and efficiency (referred to herein as “stress states”) due to differences in the printing roles performed thereby. In the above example, the side one printing duties defining the first printing role can be more demanding in terms of amount of printed output generated as compared to the side two printing duties defining the second printing role. This variation in the amount of printed output often causes the first and second printers to diverge from each other in terms of quality, replenishment of colorant (ink or toner), remaining useful life of wear parts, etc., which can be thought of as a lack of stability in the TISP/TIPP system. Any variation in quality is highly objectionable to the user, and the divergence in terms of consumption of colorant, useful life of wear components, and the like leads to inefficiencies in connection with supply usage and maintenance requirements. As such, a need has been identified for a new and improved method and system for controlling multiple printers in a TISP or TIPP system for increased stability.
In accordance with a first aspect of the present development, a method for printer stability enhancement in a multiple printer printing system includes determining a first printer stress state of a first printer in a printing system, wherein the first printer is assigned a first printing role. The method further includes determining a second printer stress state of a second printer in the printing system, wherein the second printer is assigned a second printing role that is different from the first printing role. The first printer stress state is compared to the second printer stress state, and the first printing role is reassigned to the second printer and the second printing role is reassigned to the first printer if the first printer stress state is different than the second printer stress state.
In accordance with another aspect of the present development, a system for printer stability enhancement in a multiple printer printing system includes a first printer assigned a first printing role and a second printer assigned a second printing role that is different from the first printing role. The system further includes means for reassigning the first printing role to the second printer and for reassigning the second printing role to the first printer after completion of a printing cycle.
In accordance with a further aspect of the present development, a system for printer stability enhancement in a multiple printer printing system includes means for determining a first printer stress state of a first printer in a printing system, wherein the first printer is assigned a first printing role. The system further includes means for determining a second printer stress state of a second printer in the printing system, wherein the second printer assigned a second printing role that is different from the first printing role. The system also includes means for comparing the first printer stress state to the second printer stress state, and means for reassigning the first printing role to the second printer and reassigning the second printing role to the first printer if the first printer stress state is different than the second printer stress state.
As shown in
The TISP printing system 30 is configured such that a first printing role of the print job 20 is performed by a first printer 32 (Printer #1) that is located upstream from a second printer 34 (Printer #2) that performs a second printing role of the print job 20 after the first printing role performed by the first printer 32 is completed. The second printer 34 outputs the print job to a printed output module 36 for assembling the hard copy paper printed output into the desired physical arrangement or package. The TISP printing system 30 also includes a paper path control system 38 comprising gates, inverters, cross-overs and the like, for controlling the flow of paper (or other print recording media) to and from the first and second printers 32,34.
Similarly, in the TIPP printing system 40, a first printing role of the print job 20 is performed by a first printer 42 (Printer #1) that is arranged and operates in parallel with a second printer 44 (Printer #2) that performs a second printing role of the print job 20 simultaneously with the first printing role performed by the first printer 42. The first and second printers 42,44 output their respective print jobs to a printed output module 46 for assembling the hard copy paper printed output into the desired physical arrangement or package. The TIPP printing system 40 also includes a paper path control system 48 comprising gates, inverters, cross-overs and the like, for controlling the flow of paper (or other print recording media) to and from the first and second printers 42,44.
As noted above, the stress states of the first and second printers 32,34 or 42,44 will often undesirably diverge relative to each other over time.
In response to input received by the printer control system 70, or according to an arbitrary or pre-defined schedule, the printer control system 70 provides input to the printer variation control module 60 to cause the printer variation control module 60 to select either its first state as indicated by the solid-line arrows R1,R2 or its second state as indicated by the broken-line arrows R1′,R2′. In other words, the printer control system 70 periodically causes the printer variation control module 60 to reassign the first printing role 62 to the second printer 54 and to reassign the second printing role 64 to the first printer 52, and vice versa. The printer control system 70 also receives some or all of the data defining the print job 70 for reasons described below.
As shown in
The printer control system 70 receives data from the sensors 59 and also uses the data defining and describing the print job 20 to calculate or otherwise derive first printer stress parameters that describe or indicate a stress state of the first printer 52 and to calculate or otherwise derive second printer stress parameters that describe or indicate a stress state of the second printer 54.
A description of each printer stress parameter FP1-FP7, SP1-SP7 is provided below:
This parameter describes the age of the toner (or other colorant) in terms of the time it has been residing in the development housing/sump, typically described in terms of a “mean residence time.” The printer control system 70 uses the fixed size of the development housing, the amount of toner input to the development housing and the amount of toner consumed from the development housing over a known time period to calculate the toner age parameter. A variation in toner age between the first and second printers 52,54 indicates a variation in printer stress levels.
This parameter describes the concentration of toner relative to carrier beads or other carrier material in the two-component development housing or sump. The toner concentration is measured by one of the sensors 59 and is controlled by the printer control system 70 in real-time to adjust the image density of the printed output. A variation in toner concentration between the first and second printers 52,54 indicates a variation in printer stress levels due to variations in printed output.
This parameter describes the quantity of toner being output by each printer 52,54 in terms of the area covered by the toner or other colorant. The printer control system 70 derives the area coverage parameter from the data defining the print job 20. Variation in area coverage between the first and second printers 52,54 indicates a variation in printer stress levels.
This parameter describes the detection of streaks on the photoreceptor of the printer as detected by full-width array sensors. Detection of streaks associated with one of the printers 52,54 but not the other indicates a variation in printer stress levels.
This parameter describes the voltages and other electrical characteristics of the xerographic field including the magnetic roller. The development field is measured by sensors 59 and/or is known and controlled by the printer control system 70. Differences in the development field between the first and second printers 52,54 indicates a variation in printer stress.
The laser (Raster Output Scanner (ROS)) power consumed is known by the printer control system 70. An increase in laser power consumption indicates that greater power is required to maintain the desired image density. As such, a variation in laser power between the first and second printers 52,54 indicates different levels of printer stress.
The charge level on the photoreceptor is known by the printer control system 70 and/or is measured by sensors 59. Variation in charge levels between the first and second printers 52,54 indicates different levels of printer stress due to component wear or other reasons.
In one embodiment, the select threshold used in step S4 is exceeded if any one of the stress parameter deltas Δ1-Δ7 does not equal zero. In another embodiment, the select threshold used in step S4 is exceeded if any one of the stress parameter deltas Δ1-Δ7 varies by 10% or more from either of the respectively corresponding first and second printer stress parameters FP1-FP7, SP1-SP7 used to calculate the stress parameter delta Δ1-Δ7, i.e., if the second printer stress parameter varies from the first stress parameter by 10% or more from the first stress parameter or vice versa. In other words, a tolerance range of plus or minus 10% is assigned to each of the stress parameter deltas Δ1-Δ7, and each stress parameter delta Δ1-Δ7 is deemed to indicate printer stress variation only if it falls outside the tolerance range. Also, the threshold used in step S4 can be deemed to be exceeded if one, greater than one, or all available stress parameter deltas Δ1-Δ7 fall outside the tolerance range. As such, printer stress variation indicated by any one or more of the of the stress parameter deltas Δ1-Δ7 can be ignored until a select minimum number of the available stress parameter deltas Δ1-Δ7 fall outside the tolerance range as would indicate printer stress variation outside an acceptable range.
Those of ordinary skill in the art will recognize that the above-described swapping of the first and second printing roles between the first and second printers 52,54 according to the step S4 will ensure that the variation between the respective stress states of the first and second printers 52,54 is maintained within acceptable limits.
The present development will reduce toner consumption by reducing the likelihood that the toner age FP1,SP1 of either printer 52,54 becomes elevated. In known systems 30,40, when the toner age reaches a maximum acceptable level, the system will perform a MAC (Minimum Area Coverage) Patch and/or Toner Purge routine to use toner for waste purposes by printing colorant patches on the photoreceptor and then wiping the patches into the waste toner hopper in order to drive the toner age down to an acceptable level. The system 50 and method of the present development reduces the chance that the toner age in either printer will reach the maximum acceptable level, because both printers will be used in a uniform manner relative to each other.
The claims, as originally presented and as they may be amended, are intended to encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein.
