Method for printing a quality assurance print chart, computer program product, and printing system

Abstract

The present invention provides a method for printing a Quality Assurance print chart, QA chart, comprising the steps of: determining the maximum print width for at least one media sheet to be printed subsequently to the printing of the QA chart, selecting from a plurality of media types designated as being suitable for QA charts, a media type that has substantially the same or a greater media width as the determined print width for the at least one media sheet to be printed subsequently, setting a print width for the QA chart substantially to the determined print width, and printing the QA chart with the set print width on the selected media type.

Claims

1. Method for printing a Quality Assurance print chart, QA chart, comprising the steps of: determining the maximum print width for at least one media sheet to be printed subsequently to the printing of the QA chart, selecting from a plurality of media types designated as being suitable for QA charts, a media type that has substantially the same or a greater media width as the determined print width for the at least one media sheet to be printed subsequently, setting a print width for the QA chart substantially to the determined print width, and printing the QA chart with the set print width on the selected media type.

2. Method according to claim 1, wherein: determining the maximum print width comprises determining the maximum media width.

3. Method according to claim 2, wherein: selecting from a plurality of media types designated as being suitable for QA charts comprises selecting a media type that has substantially the same media width as the determined print width for the at least one media sheet to be printed subsequently.

4. Method according to claim 2, wherein printing the QA chart comprises printing the QA chart with a print speed that is substantially the same as the print speed for the media sheet that is to be printed subsequently to the printing of the QA chart.

5. Method according to claim 1, wherein: selecting from a plurality of media types designated as being suitable for QA charts comprises selecting a media type that has substantially the same media width as the determined print width for the at least one media sheet to be printed subsequently.

6. Method according to claim 5, wherein printing the QA chart comprises printing the QA chart with a print speed that is substantially the same as the print speed for the media sheet that is to be printed subsequently to the printing of the QA chart.

7. Method according to claim 1, wherein printing the QA chart comprises printing the QA chart with a print speed that is substantially the same as the print speed for the media sheet that is to be printed subsequently to the printing of the QA chart.

8. Method according to claim 7 wherein selecting from a plurality of media types comprises selecting a media type that has a print speed associated with it that is substantially the same as the print speed associated with the media type of the media sheet that is to be printed subsequently to the printing of the QA chart.

9. A computer program product embodied on a non-transitory computer readable medium that, if executed on a processor, performs the steps of the method of claim 1.

10. A printing system configured to print a Quality Assurance print chart, QA chart, comprising: a storage storing a media catalogue, the media catalogue comprising entries for print media types, the entries comprising a media width and, if applicable for the particular media type, a designation whether the media type is suitable for printing a QA chart, a sheet scheduler storing a sequence of sheets to be printed including for a sheet the media type to print on, and a Quality Assurance module that is configured to, upon determining that a QA chart is to be printed at a position between two subsequent sheets in the sequence of sheets to be printed, print a QA chart, wherein printing a QA chart comprises: printing on a media type selected from the media types designated as being suitable for printing the QA chart and with a media width substantially the same as or greater than the maximum print width for at least one media sheet to be printed subsequently to the printing of the QA chart, and printing with a print width substantially the same as the maximum print width of the at least one media sheet to be printed subsequently to the printing of the QA chart.

11. Printing system according to claim 10, wherein printing a QA chart comprises: printing on a media type with a media width substantially the same as or greater than the maximum media width for at least one media sheet to be printed subsequently to the printing of the QA chart, and printing with a print width substantially the same as the maximum media width of the at least one media sheet to be printed subsequently to the printing of the QA chart.

12. Printing system according to claim 11, wherein printing a QA chart comprises: printing on a media type with a media width substantially the same as the maximum media width for at least one media sheet to be printed subsequently to the printing of the QA chart.

13. Printing system according to claim 11, wherein printing a QA chart comprises printing the QA chart with a print speed that is substantially the same as the print speed for the media sheet that is to be printed subsequently to the printing of the QA chart.

14. Printing system according to claim 10, wherein printing a QA chart comprises: printing on a media type with a media width substantially the same as the maximum media width for at least one media sheet to be printed subsequently to the printing of the QA chart.

15. Printing system according to claim 14, wherein printing a QA chart comprises printing the QA chart with a print speed that is substantially the same as the print speed for the media sheet that is to be printed subsequently to the printing of the QA chart.

16. Printing system according to claim 10, wherein printing a QA chart comprises printing the QA chart with a print speed that is substantially the same as the print speed for the media sheet that is to be printed subsequently to the printing of the QA chart.

17. Printing system according to claim 16 wherein printing on a media type comprises printing on a media type that has a print speed associated with it that is substantially the same as the print speed associated with the media type of the media sheet that is to be printed subsequently to the printing of the QA chart.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying schematical drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

(2) FIG. 1 is a block diagram showing the components of a general printer to which the invention may be applied.

(3) FIG. 2 is a schematic drawing showing a prior art method for printing QA charts.

(4) FIG. 3 is a schematic drawing illustrating a first method for printing QA charts according to the invention.

(5) FIG. 4 is a schematic drawing illustrating a second method for printing QA charts according to the invention.

(6) FIG. 5 is a flow diagram showing a first method according to the invention.

(7) FIG. 6 is a flow diagram showing a second method according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) The present invention will now be described with reference to the accompanying drawings, wherein the same reference numerals have been used to identify the same or similar elements throughout the several views.

(9) A typical reprographic apparatus (FIG. 1) such as a printer generally comprises a controller 110 and an engine 120.

(10) The engine 120 is responsible for low-level control of the apparatus. It deals with individual hardware components that are responsible for the reprographic process such as drives for media transport, media detectors (in the media path as well as in the input and output media trays), path switches, fusers, print heads, etc.; in general actuators and sensors 128. These actuators and sensors are connected through input/output (I/O) boards 127 to a bus 129. The bus 129 connects the major components in the engine 120. Actual data processing takes place in a central processing unit (CPU) 121. The CPU 121 reads sensor values from the sensors 128 through the I/O 127. Based on these sensor values and other data such as print data and print commands received from the controller 110, the CPU 121 determines how the engine 120 should respond to this information and determines appropriate actuation values that are sent through the I/O 127 to the actuators 128. The engine 120 comprises a volatile memory such as a random access memory (RAM) 122 to temporarily store data for processing such as the print data and print commands received from the controller 110, and the sensor values read from the sensors 128. Furthermore, a non-volatile memory such as a hard disk drive (HDD) 123 serves to store data in a more permanent manner, for example to survive a power down of the system. This hard disk drive 123 typically also stores embedded software comprising computer instructions that are run on the CPU 121. The engine 120 typically runs a real-time Operating System (RTOS), for example a soft real-time Operating System in order to deal with the time critical functions of controlling the actuators 128. The engine 120 further comprises a communication device 124 to communicate with the controller 110. Typically, the engine 120 receives print data and print commands from the controller 110 and provides back status information on the engine 120 itself and on the processing of the print commands and print data, including sending error messages to the controller 110.

(11) The controller 110 is connected to the engine 120 through a communication device 114 that communicates with the communication device 124 of the engine 120. These communication devices 114, 124 may be implemented as Ethernet network interface controllers (NIC). Processing in the controller 110 is done by a CPU 111 that is connected to all the other components in the controller 110 through a bus 119. The data to be processed is temporarily stored in a volatile memory such as RAM 112, while data is stored in a more permanent manner in a non-volatile memory such as hard disk drive 113, for example in order to survive power downs, but also to relieve the volatile memory 112 which typically has a smaller storage size. The hard disk drive 113 typically stores print jobs, each comprising print data and a job ticket. Furthermore, the hard disk drive 113 comprises converted print data which is print data converted to a format suitable for processing by the engine 120. Typically the converted print data comprises raster images. Converting the print data in the print jobs to converted print data is typically done in a Raster Image Processor (RIP). Although the RIP may be a dedicated hardware device, it is common to be implemented in software and running on CPU 111. As the RIP-process is rather computationally intensive, it is common for controllers 110 to have multiple processing units in the form of a multi-core CPU 111 or multiple CPUs 111. The controller 110 further comprises a display 116 to show messages to an operator, or display a complete graphical user interface (GUI) to an operator for operating the reprographic apparatus. The display 116 is supplemented by a human interface device (HID) 118 such as a keyboard, mouse, touchpad, stylus, or touch sensitive panel integrated into display 116, and allows the operator to operate the reprographic apparatus. The controller 110 comprises a communication interface 117 for communicating with peripheral devices such as finisher, for example, stackers, staplers, binders, punchers, cutters, trimmers, folders, media input units, etc. The controller 110 further comprises a network interface card (NIC) 115 to connect the controller 110 to a computer network. Through the network connection, print jobs may be submitted to the controller 110 and the results of scan jobs may be retrieved from the controller 110. For these operations the controller 110 may be directly in communication with individual workstations, or indirectly through a print server. Furthermore, the network connection may be used to remotely operate the reprographic apparatus, monitor its status, and send production data to monitoring systems, accounting systems, or business information systems. Note that in smaller printer models, specifically printers suitable for placement on desks, it is common to use communication interfaces such as USB, FireWire, or Bluetooth instead of the NIC 115.

(12) The controller 110 and the engine 120 may be implemented in a single printer device (typical for smaller printers for low volume printing), or as two separate, but interconnected devices (typical for larger, high-volume production printers).

(13) The engine 120 typically deals with print data on a sheet level, swath level, or even line level. The engine 120 is typically not aware of information on a document or even job level. In contrast the controller 110 typically receives print jobs comprising one or more documents, the documents typically comprising multiple pages.

(14) According to the invention the printed part of the QA chart will not extend beyond the print areas 213 and 214 of the sheets 203 and 204 (FIG. 3) that are scheduled to be printed after the QA chart has been printed. This means that the areas 251-254 have been adjusted relative to corresponding areas 251-254 in the prior art situation as shown in FIG. 2, to not extend (in the direction of the page width) beyond the print areas 213 and 214 of the subsequent sheets 203 and 204. The result is that the nozzles that will not be used for printing the subsequent sheets 203 and 204, will also not be used for printing the QA charts. Therefore, any idle time of those nozzles due to these nozzles not being used in previous sheets 201 and 202 will not trigger a maintenance action. Instead of the printer wasting time (and ink) due to a maintenance action between printing sheet 202 and printing QA chart 250, the printer will immediately proceed with printing the QA chart 250 after having printed sheet 202.

(15) According to another embodiment (FIG. 4), the printer will not just reduce the areas 251-254 of the QA chart 250 in width, but will additionally (or alternatively) use a media type for printing the QA chart 250 that has substantially the same width as the subsequent sheets 203 and 204. This allows the printer to use a simpler (and more-or-less more ignorant) approach by not specifically determining a print area 213, 214 of the subsequent sheets 203 and 204, but to only regard the media width for the subsequent sheets 203 and 204. After having determined the media width of the subsequent sheets 203 and 204, the printer selects a media type with substantially the same media width for printing the QA chart 250. In this embodiment, the areas 251-254 will typically be printed full-width (up till the media edge if the print engine has no non-printable margin, otherwise the full width of the printable area will be printed).

(16) In a further embodiment, being an intermediate form of the previous two embodiments, the printer only regards the media width of the subsequent sheets 203 and 204, and adjusts the print width of the areas 251-254 to be substantially equal to the media width of the subsequent sheets 203 and 204. In this embodiment, the QA chart 250 may still be printed on a media type that is wider than the media width of the subsequent sheets 203 and 204.

(17) It is further advantageous to use a media type for the QA chart 250 that has the smallest usable media length therewith reducing the space (and time) occupied in the media path for non-productive printing (quality assurance instead of producing an actual product).

(18) The first embodiment, wherein the printer adjusts the print width used for the QA chart 250 is further explained in relation to the flow chart 500 in FIG. 5. The method starts 502 with determining 504 the maximum print width 213, 214 of subsequent sheets 203, 204. The printer may only determine the print width 213 of only one subsequent sheet 203, or multiple subsequent sheets 203, 204, etc. The drawback of only looking at one subsequent sheet 203 is that if the next sheet 204 has a greater print width, a maintenance action may still be triggered, or that the QA chart 250 cannot cover for the quality of sheet 204 as it is wider (applicable for NFD). The disadvantage of taking into account too many subsequent sheets 203, 204, etc. is that at some point the QA chart 250 will become irrelevant for further sheets due to the remoteness or the effect of a maintenance action will have faded over time. For example, nozzle failures can often be resolved with a maintenance action. QA charts for NFD can be used to perform NFC in order to postpone a maintenance action (if the NFD itself does not trigger a maintenance action as described in relation to the prior art). However, if the maximum idle time for a nozzle is equivalent to, say 250 sheets, it is of no use to look beyond 250 sheets, because if the subsequent 250 sheets all have the same media width and the 251st sheet is wider, the extra nozzles used for this 251st sheet will not have been used during the previous 250 sheets and a maintenance action is therefore due anyway.

(19) After the method has determined 504 the maximum print width for the subsequent sheets 203, 204, a media type is selected 506 from the media types available for QA chart printing, the media type having a width that is at least as wide as the media of the subsequent media sheets 203, 204. In a next step the print width for the QA chart 250 is set 508 to the maximum print width of the subsequent sheets 203, 204 as determined in the earlier step 504. Then based on the selected QA chart media type and set print width, the QA chart 250 is printed 510 and the procedure finishes 512 and is re-executed when the print engine determines that a further QA chart 250 is to be printed.

(20) The method 600 according to the second embodiment is shown in FIG. 6. This method 600 corresponds to the method 500 of the first embodiment as illustrated previously with regard to FIG. 5. The steps 602 and 606-612 are equal to the steps 502 and 506-512 of method 500 respectively. The difference is in the determining step 604. Where the first method 500 determines 504 a maximum print width for the subsequent sheets 203, 204, the second method 600 determines 604 a maximum media width for the subsequent sheets 203 and 204.

(21) Note that the embodiments shown herein use a QA chart 250 for NFD as example. However, the invention is also applicable to the printing of other types of QA charts 250, for example but not limited to colour charts. Any QA chart 250 that prints outside the print areas 213 and 214 of the subsequent sheets, may trigger an unnecessary maintenance action and therefore the present invention will be advantageous.

(22) Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. In particular, features presented and described in separate dependent claims may be applied in combination and any advantageous combination of such claims are herewith disclosed.

(23) Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention. The terms a or an, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly.

(24) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.