Print scaling correction mechanism

Abstract

To disclose an art related to image processing in a printing system.SOLUTION: A system includes: at least one physical memory device to store a scaling correction logic; and one or more processors connected with the at least one physical memory device. The one or more processors execute the scaling correction logic to receive first measured print image data associated with test marks printed on a first surface of a print medium based on a print job and second measured print image data associated with test marks printed on the second surface of the print medium, generate a first surface scaling factor on the basis of the first measured print image data and a second surface scaling factor on the basis of the second measured print image data, and generate a scaling factor correction on the basis of the first surface scaling factor and the second surface scaling factor generated.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to the field of printing systems, and more particularly to image processing in a printing system.

Background Art

[0002] Entities having a substantial printing demand typically implement high-speed production printers for volume printing (e.g., 100 pages per minute or more). The production printer may include a continuous paper printer that prints on a long web of printing media (such as paper) stored on a large roll. The production printer typically includes a localized printing controller that controls the overall operation of the printing system and one or more printing engines that include one or more print head assemblies, and each print head assembly includes an array of print heads. Each printing engine may be 3 meters or more in length. Each print head includes a number of nozzles (e.g., inkjet nozzles) for ejecting ink or any marking material suitable for printing on the printing media.

Summary of the Invention

[0003] In one embodiment, the system includes at least one physical memory device storing scaling correction logic, and one or more processors connected to the at least one physical memory device, and the one or more processors execute the scaling correction logic to receive first evaluation print image data associated with a test mark printed on a first side of a printing medium based on a print job, and second evaluation print image data associated with a test mark printed on a second side of the printing medium, generate a first side scaling factor based on the first evaluation print image data, generate a second side scaling factor based on the second evaluation print image data, and generate a scaling factor correction based on the generated first side scaling factor and the second side scaling factor.

Brief Description of the Drawings

[0004] A better understanding of the present invention can be obtained from the following drawings and the following embodiments for carrying out the invention.

[0005] [Figure 1] This is a block diagram of one embodiment of a printing system.

[0006] [Figure 2A] This is a block diagram showing an embodiment of a print controller. [Figure 2B] This is a block diagram showing an embodiment of a print controller. [Figure 2C] This is a block diagram showing an embodiment of a print controller.

[0007] [Figure 3] One embodiment of a scaling module is shown.

[0008] [Figure 4A] An embodiment of the finder mark is shown. [Figure 4B] An embodiment of the finder mark is shown.

[0009] [Figure 5] This document shows one embodiment of a print verification system.

[0010] [Figure 6] This shows one embodiment of the scaling correction logic.

[0011] [Figure 7A] An embodiment of a graphical user interface is shown. [Figure 7B] An embodiment of a graphical user interface is shown.

[0012] [Figure 8] This is a flowchart illustrating one embodiment of the process for scaling correction.

[0013] [Figure 9] This is a flowchart illustrating another embodiment of the scaling correction process.

[0014] [Figure 10] This shows one embodiment of a computer system. [Modes for carrying out the invention]

[0015] Implementing multiple print engines in high-speed production printers often leads to problems related to paper shrinkage. For example, paper (or other printing medium) starts at room temperature with some moisture. However, after the first side of the paper is printed and dried by the first print engine, a considerable amount of shrinkage can occur. Furthermore, the paper cools before the second side is printed and dried by the second print engine, where a different amount of shrinkage occurs. Due to the different amounts of shrinkage on each side, the image size printed on the front and back of the paper often differs even when the same print instructions are used for both sides.

[0016] Conventional methods for compensating for such shrinkage involve manually inspecting printed pages and estimating how the front and back sides align to determine how the two sides should scale. Appropriate scaling is then performed to compensate for the amount of shrinkage (e.g., by scaling down two sides or increasing one side until they match). Other parameters within the printing system, such as ink coverage (e.g., the amount of ink applied to the page), the operating point of the dryer (e.g., temperature or airflow), and the paper's moisture content, also affect the amount of shrinkage. Furthermore, this scaling compensation process must be performed for each type of paper implemented in the printer, due to the different physical properties of the paper type that affect paper shrinkage.

[0017] According to one embodiment, a mechanism for automatically performing scaling correction to compensate for paper shrinkage is described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent to one of ordinary skill in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the underlying principles of the present invention.

[0018] In the specification, reference to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

[0019] Throughout this document, terms such as “logic,” “component,” “module,” “engine,” “model,” “computer,” etc. may be referred to interchangeably and may include, by way of example, any combination of software and hardware such as software, hardware, and / or firmware. Further, any use of specific brands, words, terms, phrases, names, and / or acronyms is not to be read as limiting the embodiments to the software or device that conveys its label in a product or literature outside of this document.

[0020] Figure 1 is a block diagram showing one embodiment of the printing system 100. As shown in Figure 1, the printing system 100 includes a tandem duplex continuous paper printer 100, which includes a first printing engine 110, a second printing engine 120, and a print controller 200. The first printing engine 110 and the second printing engine 120 each have an inlet 114, an outlet 116, one or more print heads 112, etc. A paper feed unit 160 supplies paper 140 (a continuous paper printing medium, for example, also known as a web) to the printing system and is typically a paper roll unwinder that unwinds paper from a large roll. The paper 140 exits the paper feed unit 160 and is fed into the inlet of a splicing unit 190. When the paper rolls in the paper feed unit 160 are nearing the end, the splicing unit 190 responds by applying a splice between a section of paper from the nearly empty first roll and a section of paper from the full second roll. The second paper roll may be part of the paper feeding unit 160 or the splicing unit 190.

[0021] Furthermore, the paper feed unit 160 and / or the splicing unit 190 may include a web buffer (e.g., a web festoon) for storing the length of a paper 140 (e.g., a web) having faces 140A and 140B. One use of the web buffer is to increase the time from the detection of a splice 144 until the splice 144 reaches the inlet 114 of the first printing engine 110 by storing a known amount of web length and positioning a sensor 102 for detecting splices upstream of the web buffer. The amount of web length stored may be constant and fixed, or it may be identified in other ways when the splice 144 is detected by the sensor 102.

[0022] In other embodiments, the functions of the paper feed unit 160 and the splicing unit 190 may be combined into a single device. The paper 140 exits the splicing unit 190, is supplied to the inlet 114 of the print engine, travels along the paper path 128 through the print engine 110, passes through the print head 112, and exits from the outlet 116. Other components of the print engines 110 and 120, such as paper rollers, paper guides, paper drive mechanisms, paper tensioners, and dryers, are not shown for brevity. In addition to the continuous paper roll format, the paper 140 may be a folded type of continuous paper that can be supplied to the first print engine 110 as an alternative.

[0023] The paper 140 may include one or more splices 144 fixed to one or more sections of the paper 140. During printing, the paper 140 generally moves in the paper processing direction 142 (e.g., the x-direction). The paper path 128 is a physical path in which the paper 140 is taut (e.g., tight) as it starts from the paper feed unit 160 and ends at the post-processing device 170, and includes the path within all devices in between. The print head 112 includes one or more pixel-forming elements that use the marking material applied to the paper 140 to directly or indirectly (e.g., by moving the marking material through an intermediate) form the display of picture elements (pixels) on the paper 140 (e.g., the printing medium).

[0024] In an inkjet printer, the pixel-forming element is a tangible device that ejects ink onto paper (e.g., an inkjet nozzle), and in an electrophotographic (EP) printer, the pixel-forming element may be a tangible device that determines the position of toner particles to be printed on the printing medium (e.g., an EP exposure LED or an EP exposure laser). Furthermore, the pixel-forming element may be assigned to one or more color planes corresponding to the type of marking material (e.g., cyan, magenta, yellow, and black (CMYK)). The space between the nozzle surface of the print head 112 and the surface of the paper 140 (or the surface of the splice 144) facing away from the nozzle surface of the print head 112 is the print head gap 126.

[0025] Paper 140 is transported through the paper reversal unit 150 at the output of the first printer, and the second printer prints on the reverse side of the output of the first printer, thereby achieving tandem double-sided printing. The functions of each unit in the second printing engine 120, such as the inlet 114, outlet 116, and one or more print heads 112, are the same as those of the first printing engine 110. The print controller 200 receives print job data from the host computers 130, 132, etc., performs the drawing process, and then outputs image data to the first printing engine 110 and the second printing engine 120.

[0026] The host computer 130 is connected to the print controller 200 via a network 135. The network 135 may be a LAN, WAN, or cloud. The host computer 132 is connected to the print controller 200 via a local interface. Physically, the local interface is implemented as a printer local I / F cable. In tandem duplex printing mode, the paper reversal unit 150 reverses the printed side of the paper 140 with respect to the first side printed by the first print engine 110, and outputs the paper 140 from the exit 116 toward the second print engine 120. In tandem single-sided printing mode, the paper 140 passes through the paper reversal unit 150 without being reversed. The second print engine 120 receives the paper 140 that has been transported through the paper reversal unit 150 at the inlet 114 of the second print engine 120. A paper path mechanism (not shown) guides the paper 140 along the paper path 128 toward the printing process, such as the print head 112 of the second printing engine 120.

[0027] In this way, by using the paper reversal unit 150, printing is performed first by the first printer engine 110, and then by the second printing engine 120, thereby achieving tandem double-sided printing. The paper 140 printed by the second printing engine 120 is output through the exit 116 to the print verification system (PVS) 180 or post-processing device 170, according to the paper loading by the operator.

[0028] In one embodiment, the PVS180 is implemented to capture a printed image of the surface of a printing substrate (e.g., paper) and to determine print quality defects on the substrate. Print quality defects may be defects from defective print markings on the substrate and / or physical defects within the substrate (e.g., impurities, spots, stains, flutter, temporary wrinkles, creases, and / or z-direction defects). In one embodiment, the PVS180 may transmit the captured printed image and report the results of any detected defects to the print controller 200 for further processing.

[0029] The post-processing device 170 may be a paper roll rewinder or a sheet cutter equipped with a sheet stacker. Output to the paper roll rewinding type post-processing device 170 is particularly effective when a paper roll unwinding type paper feed unit 160 is used as the paper feed for the first printing engine 110.

[0030] In tandem duplex printing mode, the first printing engine 110 prints on one side of the paper 140, after which the paper 140 is flipped by the paper flipping unit 150 and then supplied to the second printing engine 120. The second printing engine 120 prints on the reverse side of the flipped paper 140; that is, the second printing engine 120 prints on the opposite side of the paper 140 that was printed by the first printing engine 110. In tandem single-sided printing mode, the first printing engine 110 prints on one side of the paper 140, after which the paper flipping unit 150 supplies the paper 140 to the second printing engine 120 without flipping it. The printing system 100 may be configured to allow the paper 140 to remain unflipped by bypassing the paper flipping unit 150 or by removing the paper flipping unit 150 from the printing system 100. When this configuration is adopted, the second printing engine 120 will also perform printing on the surface of the paper 140, just like the first printing engine 110.

[0031] Figures 2A and 2B are block diagrams showing embodiments of the print controller 200. As shown in Figure 2A, the print controller 200 (e.g., DFE or digital front end) in its generalized form includes an interpreter module 212, a halftone processing module 214, and a scaling module 220. Figure 2B shows an alternative embodiment having print controllers 200A and 200B. In this embodiment, print controller 200A includes an interpreter module 212 and a halftone processing module 214, and print controller 200B includes a scaling module 220. Print controllers 200A and 200B may be implemented within the same printing system 100 (as shown) or separately.

[0032] The interpreter module 212 is operable to interpret, render, rasterize, or otherwise convert images of a print job (e.g., raw sheet-side images such as sheet image 120) into sheet-side bitmaps. Each sheet-side bitmap generated by the interpreter module 212 is a two-dimensional array of pixels representing the image of the print job (i.e., a Continuous Tone Image, CTI), also known as a full sheet-side bitmap. A two-dimensional array of pixels is considered a “full” sheet-side bitmap because the bitmap contains a set of pixels of the image. In one embodiment, the interpreter module 212 is operable to interpret or render multiple raw sheet-sides simultaneously such that the rendering speed substantially matches the image processing speed of the production print engine.

[0033] The halftone processing module 214 can operate to represent a sheet-side bitmap as an ink halftone pattern. For example, the halftone processing module 214 may convert pixels into a CMYK ink halftone pattern for application to paper. The halftone design may include a predefined mapping of input pixels to gray-level output droplet sizes based on pixel position.

[0034] As described above, the problem of different shrinkage amounts between the front and back surfaces of the paper 140 when operating in duplex printing mode can lead to undesirable differences in printed image size between the two surfaces of the paper 140. According to one embodiment, a scaling module 220 is implemented to facilitate automatic scaling to compensate for such shrinkage.

[0035] Figure 3 shows one embodiment of a scaling module 220, which includes a test page generator 310, an interface 320, and scaling application logic 330. The test page generator 310 generates a quality test page having a pattern that facilitates scaling measurements on the PVS 180. In one embodiment, the quality test page includes finder marks (or test marks) that extend across the paper 140 at known locations. Figure 4A shows one embodiment of a test page with test marks 410, and Figure 4B shows one embodiment of a close-up view of the test marks 410.

[0036] In a further embodiment, test marks are printed by the print engines 110 and 120 on each printable surface of the paper 140 according to a test mark print command. In this embodiment, the test marks on two surfaces are not commanded to be positioned to overlap each other, which has the technical advantage of reducing ink bleeding through other surfaces of paper that could interfere with scaling measurements. In yet another embodiment, the quality test page may include a separate test page used during offline printer calibration. In another embodiment, the test marks are printed without applying scaling factor correction, which has the advantage that other processes that rely on the same text marks are not affected by the scaling of the test marks. However, in an alternative embodiment, the test page may be incorporated into the production print page during the processing of an online print job, which has the technical advantage of not using a separate test page that is discarded after printing. In this embodiment, each test page print command is included in the print command associated with the print job.

[0037] Referring to Figure 3, interface 320 includes an application programming interface (API) that facilitates communication with the scaling correction logic in PVS180. In one embodiment, interface 320 is configured to receive update messages from PVS180. In such embodiments, the update message includes a scaling factor correction (or updated scaling factor correction) generated in PVS180. In other embodiments, the update message may include a scaling factor error message, as will be discussed in more detail below. The scaling application logic 330 applies the scaling factor correction to the print instructions associated with the print job being printed. In one embodiment, the scaling factor correction is applied to the processing of the print instructions in the interpreter module 212.

[0038] Once printed on paper 140, the test page is then received by the PVS 180 for quality inspection. Figure 5 shows one embodiment of the PVS 180, including an image capture device 510, a registration engine 520, and a controller interface 540. In one embodiment, the image capture device 510 includes one or more cameras. However, in other embodiments, the image capture device 510 may include different types of image capture devices.

[0039] The image capture device 510 may provide image measurements (e.g., pixel reflectance, intensity, position, etc.) for each of one or more color bands. In such embodiments, one or more image capture devices 510 capture (or scan) an image of the print medium after bitmap print image data (or bitmap data) has been applied to the print medium using a marking material. The image capture device 510 may transmit the resulting print image data corresponding to one or more color bands (e.g., red, green, blue, etc.) and / or grayscale bands. In one embodiment, the image capture device 510 captures an image of test marks printed on a test page and generates evaluation print image data (or evaluation reference image data) for each face of the test page. In a further embodiment, the evaluation print image data includes the pixel positions of the test marks.

[0040] The registration engine 520 receives the obtained evaluation print image data (e.g., print image) and registers the evaluation print image data and the expected print image data (e.g., bitmap print image data, bitmap image, or other test mark source print instructions that identify the indicated position and / or dimensions of the test marks on the test page). The registration engine 520 may access the expected print image data by receiving or retrieving it from stored memory. According to one embodiment, the registration process may be implemented by performing color conversion, rotation, skew conversion, translation, and / or scaling operations on the print media image and / or bitmap image to obtain a matched alignment between the test marks in the evaluation print image data and the test marks in the expected print image data. Thus, the registration engine may include scaling correction logic 530 for performing scaling corrections based on the test marks contained in various test pages. The controller interface 540 includes an API configured to interface with the interface 320 of the print controller 200. In one embodiment, the controller interface 540 sends an update message to the interface 320 that includes scaling factor corrections.

[0041] Figure 6 shows one embodiment of the scaling correction logic 530. According to one embodiment, the scaling correction logic 530 receives a first evaluation print image data associated with printed test marks on paper 140 from a first side of the print image of a print job, and a second evaluation print image data associated with printed test marks from a second side of the print image, generates a first surface scaling coefficient based on the first evaluation print image data and the expected print image data, generates a second surface scaling coefficient based on the second evaluation print image data and the expected print image data, generates a first page scaling coefficient including the first surface scaling coefficient and the second surface scaling coefficient, and generates a scaling coefficient correction based on the page scaling coefficient. As used herein, the surface scaling coefficient represents the amount of scaling for one or more dimensions of a single print medium surface, the page scaling coefficient represents the surface scaling coefficient for each surface of the print medium, and the scaling coefficient correction represents adjusting to match the format of the print command. For example, if the print command has a command for scaling, the page scaling coefficient is adjusted to be compatible with the print command. This may include expressions such as percentages, relative quantities, absolute quantities, and converted units of measurement.

[0042] As shown in Figure 6, the scaling correction logic 530 includes a scaling logic 610, a correction coefficient generation module 620, a correction coefficient database 630, and a scaling coefficient monitor 640. The surface scaling logic 610 generates surface scaling coefficients by comparing dimensions. The scaling coefficients may be determined for one or more test mark dimensions. For example, the test mark dimensions may include a first dimensional component and a second dimensional component (e.g., dimensions in the process direction x and cross-process direction y, which are Cartesian coordinate dimensions on the printable surface of the printed page) from the evaluation print image data and the expected print image data (e.g., data including the dimensions and / or position of the expected test marks). In one embodiment, the comparison is performed for each surface of the print medium (e.g., dimensions from the evaluation print image of a first surface are compared with the corresponding dimensions from the expected print image of the first surface). The expected print image data may be included in a print command associated with the print job (e.g., received or retrieved from stored memory). The scaling logic 610 may determine the measured dimensions from the evaluation print image data (e.g., by counting pixels containing the identified test marks).

[0043] According to one embodiment, generating a surface scaling factor for each face involves averaging the measured dimensions of two or more test marks. The technical advantage of this averaging is that the influence of spurious measurement data is minimized. In a further embodiment, an affine matrix (e.g., a two-dimensional affine transformation) is used to determine the scaling factor for each face (e.g., by determining the coefficients of the affine matrix). As used herein, affine is a mathematical method that transforms measured test mark positions into expected test mark positions. By using the parameters of the affine matrix, scaling factors, rotations, and translations can be determined. However, in this case, this function uses the scaling factor result. The technical advantage of applying an affine matrix is ​​that the scaling factor is determined with less computational load than other methods.

[0044] According to one embodiment, the scaling logic 610 generates a page scaling factor, which includes a surface scaling factor generated for each page face. The correction factor generation module 620 is implemented to generate a scaling factor correction that is sent to the scaling application logic 330 of the print controller 200 (e.g., via interfaces 540 and 320) for application to subsequent print jobs or pages of the current print job. The scaling factor correction may include corrections for one or more dimensions.

[0045] In one embodiment, the scaling factor correction is stored in the correction factor storage 630. In such an embodiment, the scaling factor correction is stored according to a media identifier associated with the print medium (e.g., media metadata such as media type or media name). In a further embodiment, the scaling factor correction may be stored together with other print processing parameters specific to the print medium identifier. Thus, multiple print medium print processing parameter sets may be stored together with other print processing parameters specific to the print medium identifier. The stored data is then retrieved (e.g., using the media identifier) ​​and applied during printing of subsequent print jobs using the same print medium, thus providing the technical advantage of avoiding another cycle of test page measurement. For example, the scaling correction logic 530 may receive notification of a second print job to be printed on a second print medium, retrieve a second scaling factor correction based on the second print medium identifier (e.g., a second print medium identifier included in the second print job), and apply the second scaling factor correction to the print command associated with the second print job.

[0046] According to one embodiment, the updated scaling factor correction may be generated based on the average of several previous scaling factor correction amounts. For example, the scaling factor correction generated based on the scaling process of a first test page and the scaling factor correction generated based on the scaling process of a second test page are averaged to generate the updated scaling factor correction. The technical advantage of averaging is that the updated scaling factor correction does not change abruptly from the previous scaling factor correction amount, and the difference in print output generated with the updated scaling factor is not very noticeable to a human observer.

[0047] In another embodiment, the scaling correction logic 530 may receive a third evaluation print image data associated with printed test marks on the printing medium from a first side of the second page image of the print job, and a fourth evaluation print image data associated with printed test marks on the printing medium from a second side of the second page image, generate a third surface scaling coefficient based on the third evaluation print image data, generate a fourth surface scaling coefficient based on the fourth evaluation print image data, generate a second page scaling coefficient based on the third surface scaling coefficient and the fourth surface scaling coefficient, and update the scaling coefficient correction based on the second page scaling coefficient.

[0048] The scaling factor monitor 650 monitors the scaling factor during production printing and determines whether the difference between two corresponding generated scaling factors (e.g., area scaling factor, page scaling factor, and / or scaling factor correction) generated at different times exceeds a predetermined threshold. In one embodiment, if it is determined that the difference between different scaling factors exceeds a threshold, a scaling factor error message is generated. In a further embodiment, the scaling factor error message is included in an update message sent to the scaling module 220 and displayed as an operator alert on the graphical user interface (GUI) 350 (Figure 3). In yet another embodiment, upon receiving a scaling factor error message, the scaling application logic 330 may generate a trigger to stop the printer 100 and / or to start calculating a new scaling value. The technical advantage of determining scaling factor errors is that the scaling correction logic 530 can initiate an alert message to the operator to take recovery action and / or initiate recovery action in response to the scaling factor error, thus minimizing the amount of printed output with scaling problems.

[0049] GUI350 may also be implemented to allow operator selection to provide real-time correction options, including front-to-back alignment options. For example, the user may choose to compensate for front-to-back alignment when a test mark (e.g., a scaling test mark) is used in conjunction with other quality test marks (e.g., uniformity marks, density marks, and / or alignment marks) included in a printed "Quality Check" page, inserted at specified intervals. This has the technical advantage of reducing the number of separate test pages required when a scaling mark is not located on the same page as other quality marks. Figures 7A and 7B show embodiments of GUI350 that include various front-to-back alignment options, including scaling operations.

[0050] Although described as being included within the PVS180, the scaling correction logic 530, or one or more of its components, may be implemented in the print controller 200. Figure 2C shows an embodiment in which the scaling correction logic 530 is included in the print controller 200B having a scaling module 220. In this embodiment, the measurements generated by the image capture device 510 are sent to the print controller 200A via interfaces 540 and 320, where scaling correction is performed.

[0051] Figure 8 is a flowchart illustrating one embodiment of the scaling correction process 800 (for example, performed on the print controller 200). Process 800 may be performed by processing logic that may include hardware (e.g., circuit configuration, dedicated logic, programmable logic, etc.), software (such as instructions that run on the processing device), or a combination thereof. Process 800 is shown as a linear sequence for brevity and clarity, but it is intended that any number of them may be performed in parallel, asynchronously, or in different orders. For brevity, clarity, and ease of understanding, many of the details discussed with reference to Figures 1-7 are not discussed or repeated here.

[0052] In processing block 810, a test page is generated containing test marks to be printed on each printable side of the test page. The test page is then inserted into a print command. In processing block 820, the page image is printed. After scaling correction is performed, an update message is received (block 830). In determination block 840, it is determined whether the update message contains a scaling factor error message. If not, the update message contains a scaling factor correction (or updated scaling factor correction) that will be applied to subsequent pages to be printed (for example, by inserting the scaling factor correction into the print command for the corresponding side processed by the print controller 200) (processing block 850). The scaling factor correction is applied to one or more dimensions of the corresponding side of the subsequent pages to be printed. However, if determination block 840 determines that a scaling factor error message has been received, the error message is displayed in GUI 350 (processing block 860). In processing block 870, if applicable, a correction action (for example, stopping printing) is performed.

[0053] Figure 9 is a flowchart illustrating one embodiment of the scaling correction process 900 (for example, performed on the PVS180). Process 900 may be performed by processing logic that may include hardware (e.g., circuit configuration, dedicated logic, programmable logic, etc.), software (such as instructions that run on the processing device), or a combination thereof. Process 900 is shown as a linear sequence for brevity and clarity, but it is intended that any number of them may be performed in parallel, asynchronously, or in different orders. For brevity, clarity, and ease of understanding, many of the details discussed with reference to Figures 1-8 are not discussed or repeated here.

[0054] In processing block 910, test marks on both sides of the test page are captured. In processing block 920, measurement data including test mark dimensions is generated for the captured test marks. In processing block 930, a surface scaling factor is generated by comparing the dimensions based on the evaluation print image data with the dimensions based on the expected print image data. As discussed above, the surface scaling factor may also be generated by averaging two or more test marks (for example, by an affine transformation performed on the averaged measured dimensions).

[0055] In processing block 940, a page scaling factor is generated (e.g., the generated page scaling factor). In determination block 950, it is determined whether the difference between the generated page scaling factor and the previous page scaling factor is greater than a predetermined threshold. If so, a scaling factor error message is generated (processing block 960). In processing block 970, the scaling factor error message is sent (e.g., to the print controller 200).

[0056] If the determination block 950 determines that the difference between the page scaling factor and the previous page scaling factor is not greater than a predetermined threshold, a scaling factor correction (or updated scaling factor correction) is generated (processing block 980). As discussed above, the updated scaling factor correction may include the averaging of two or more previously generated scaling factor corrections. In processing block 990, the scaling factor correction is stored (for example, along with the associated print medium identifier) ​​before being sent in processing block 970 (processing block 990).

[0057] Figure 10 shows a computer system 1300 in which printers 110 and 120, a printing system 100, a print controller 200 and / or PVS 190 may be implemented. The computer system 1300 includes a system bus 1320 for communicating information and a processor 1310 connected to the bus 1320 for processing information.

[0058] The computer system 1300 further includes random access memory (RAM) or other dynamic storage device 1327 (hereinafter referred to as main memory) connected to the bus 1320 for storing information and instructions executed by the processor 1310. The main memory 1325 may also be used to store temporary variables or other intermediate information during the execution of instructions by the processor 1310. The computer system 1300 may also include read-only memory (ROM) and / or other static storage device 1326 connected to the bus 1320 for storing static information and instructions used by the processor 1310.

[0059] A data storage device 1327, such as a magnetic disk or optical disk and its corresponding drive, may also be connected to the computer system 1300 for storing information and instructions. The computer system 1300 may also be connected to a second I / O bus 1350 via an I / O interface 1330. Multiple I / O devices, including a display device 1324 and input devices (e.g., a keyboard 1323 (e.g., an alphanumeric input device) and / or a cursor control device 1322), may be connected to the I / O bus 1350. A communication device 1321 is for accessing other computers (servers or clients). The communication device 1321 may also include other well-known interface devices, such as a modem, a network interface card, or one used to connect to Ethernet®, Token Ring, or other types of networks.

[0060] Embodiments of the present invention may include various steps described above. These steps may be embodied in machine-executable instructions. These instructions may be used to cause a general-purpose processor or a dedicated processor to perform specific steps. Alternatively, these steps may be performed by specific hardware components containing hardwired logic for performing the steps, or by any combination of programmed computer components and custom hardware components.

[0061] Elements of the present invention may also be provided as machine-readable media for storing machine-executable instructions. Machine-readable media include, but are not limited to, floppy disks, optical disks, CD-ROMs, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, propagation media, or other types of media / machine-readable media suitable for storing electronic instructions. For example, the present invention may be downloaded as a computer program that can be transferred from a remote computer (e.g., a server) to a requesting computer (e.g., a client) via a communication link (e.g., a modem or network connection) by data signals embodied on a carrier wave or other propagation medium.

[0062] The following sections and / or examples relate to further embodiments or examples. Details in the examples may be used in any one or more embodiments. Various features of the various embodiments or examples may be combined in various ways with some features included and others excluded to suit various different uses. Examples may include subject matter such as a method, means for performing the action of the method, and at least one machine-readable medium, apparatus or system that, when performed by a machine, includes instructions causing the machine to perform the action of the method.

[0063] Some embodiments relate to Example 1, which includes a system comprising: at least one physical memory device storing scaling correction logic; and one or more processors connected to the at least one physical memory device, wherein the one or more processors perform scaling correction logic to receive first evaluation print image data associated with test marks printed on a first side of a print medium based on a print job and second evaluation print image data associated with test marks printed on a second side of the print medium; generate a first surface scaling coefficient based on the first evaluation print image data and a second surface scaling coefficient based on the second evaluation print image data; and generate scaling coefficient corrections based on the generated first and second surface scaling coefficients.

[0064] Example 2 includes the subject matter of Example 1, which generates a surface scaling factor by comparing dimensions based on evaluation print image data with dimensions based on expected print image data expected from a print job.

[0065] Example 3 includes the subject matter from Examples 1 and 2, which generates an area scaling factor based on the expected print image data expected from a print job, and is included in the print command associated with that print job.

[0066] Example 4 incorporates the themes from Examples 1-3, generating a surface scaling factor by averaging two or more measured dimensions of test marks.

[0067] Example 5 includes the themes from Examples 1-4, where the surface scaling factor includes a first dimensional scaling component and a second dimensional scaling component.

[0068] Example 6 includes the themes of Examples 1-5, further involving generating surface scaling factors by performing an affine transformation on averaged and measured dimensions.

[0069] Example 7 includes the subjects from Examples 1-6, where the test marks are printed without applying scaling factor correction.

[0070] Example 8 includes the themes from Examples 1-7, where the scaling correction logic further stores the scaling coefficient correction.

[0071] Example 9 includes the themes of Examples 1-8, where the scaling correction logic further associates the scaling factor correction with a print medium identifier associated with the print medium, and stores the scaling factor correction.

[0072] Example 10 includes the themes of Examples 1-9, wherein the scaling correction logic further performs the following: receiving notification of a second print job to be printed on a second print medium; retrieving a second scaling factor correction based on the print medium identifier of the second print medium; and applying the second scaling factor correction to the print command associated with the second print job.

[0073] Example 11 includes the themes of Examples 1-10, wherein the scaling correction logic further receives a third evaluation print image data associated with a test mark printed on the print medium from a first side of the second page image of the print job, and a fourth evaluation print image data associated with a test mark printed on the print medium from a second side of the second page image; generates a third surface scaling factor based on the third evaluation print image data and a fourth surface scaling factor based on the fourth evaluation print image data; and updates the scaling factor correction based on the generated third and fourth surface scaling factors.

[0074] Example 12 includes the themes of Examples 1-11, wherein the scaling correction logic further generates an updated scaling factor correction based on the average of a first page scaling factor based on the generated first and second surface scaling factors and a second page scaling factor based on the generated third and fourth surface scaling factors.

[0075] Example 13 includes the themes of Examples 1-12, wherein the scaling correction logic further determines whether the difference between the scaling factor correction before the update and the scaling factor correction after the update exceeds a predetermined threshold, and if it determines that the difference exceeds the predetermined threshold, it generates an alert.

[0076] Example 14 includes the themes of Examples 1-13, further comprising one or more image capture devices for capturing images of a print job.

[0077] Example 15 includes the themes of Examples 1-14, but further includes one or more printers that print the print job.

[0078] Some embodiments relate to Example 16, which includes a method comprising: receiving a first evaluation print image data associated with a test mark printed on a first surface of a print medium based on a print job, and a second evaluation print image data associated with a test mark made on a second surface of the print medium; generating a first surface scaling factor based on the first evaluation print image data, generating a second surface scaling factor based on the second evaluation print image data, and generating a scaling factor correction based on the generated first and second surface scaling factors.

[0079] Example 17 includes the subject of Example 16, which generates a surface scaling factor by comparing dimensions based on evaluation print image data with dimensions based on expected print image data expected from a print job.

[0080] Example 18 includes the subject matter of Examples 16 and 17, which generates an area scaling factor based on the expected print image data expected from a print job, and is included in the print command associated with that print job.

[0081] Example 19 includes the subject matter from Examples 16–18, which generates a surface scaling factor by averaging two or more measured dimensions of test marks.

[0082] Example 20 includes the themes of Examples 16-19, further including the storage of scaling factor corrections.

[0083] Some embodiments relate to Example 21, which includes a computer-readable medium storing instructions, wherein when the instructions are executed by one or more processors, the processors cause the processors to: receive first evaluation print image data associated with test marks printed on a first surface of the print medium based on a print job, and second evaluation print image data associated with test marks printed on a second surface of the print medium; generate a first surface scaling coefficient based on the first evaluation print image data, generate a second surface scaling coefficient based on the second evaluation print image data, and generate a scaling coefficient correction based on the generated first and second surface scaling coefficients.

[0084] Example 22 includes the subject matter of Example 21, which generates a surface scaling factor by comparing dimensions based on evaluation print image data with dimensions based on expected print image data expected from a print job.

[0085] Example 23 includes the subject matter from Examples 21 and 22, which generates an area scaling factor based on the expected print image data expected from a print job, as included in the print command associated with that print job.

[0086] Example 24 incorporates the themes from Examples 21–23, which generate a surface scaling factor by averaging two or more measured dimensions of test marks.

[0087] Example 25 includes the themes of Examples 21-24, further including the storage of scaling factor corrections.

[0088] Many changes and modifications to the present invention will be obvious to those skilled in the art after reading the foregoing description, but it should be understood that any particular embodiment shown and described herein is not intended to be considered limiting in any way. Accordingly, reference to the details of various embodiments is not intended to limit the scope of the claims, which would otherwise only define features that are considered essential in themselves.

Claims

1. It is a system, At least one physical memory device for storing scaling correction logic, The system includes one or more processors connected to the at least one physical memory device, wherein the one or more processors execute the scaling correction logic. To receive a first evaluation print image data associated with a test mark printed on a first side of a print medium based on a print job, and a second evaluation print image data associated with a test mark printed on a second side of the print medium, A first surface scaling coefficient is generated based on the first evaluation print image data, and a second surface scaling coefficient is generated based on the second evaluation print image data, A scaling coefficient correction is generated based on the first surface scaling coefficient and the second surface scaling coefficient that have been generated. Receiving a third evaluation print image data associated with a test mark printed on the printing medium from the first side of the second page image of the print job, and a fourth evaluation print image data associated with a test mark printed on the printing medium from the second side of the second page image, A third surface scaling coefficient is generated based on the third evaluation print image data, and a fourth surface scaling coefficient is generated based on the fourth evaluation print image data, The scaling coefficient correction is updated based on the generated third surface scaling coefficient and fourth surface scaling coefficient, The process involves determining whether the difference between the scaling coefficient correction before the update and the scaling coefficient correction after the update exceeds a predetermined threshold, A system that generates an alert when it is determined that the difference exceeds a predetermined threshold.

2. The system according to claim 1, which generates a surface scaling factor by comparing dimensions based on evaluation print image data with dimensions based on expected print image data expected from the print job.

3. The system according to claim 2, which generates an area scaling factor based on the expected print image data expected from the print job, which is included in the print command associated with the print job.

4. The system according to claim 2, wherein a surface scaling factor is generated by averaging two or more measured dimensions of the test marks.

5. The system according to claim 4, wherein the surface scaling coefficient includes a first dimensional scaling component and a second dimensional scaling component.

6. The system according to claim 5, wherein generating the surface scaling coefficient further comprises performing an affine transformation on the averaged and measured dimensions.

7. The system according to claim 1, wherein the test marks are printed without applying the scaling factor correction.

8. The system according to claim 1, wherein the scaling correction logic further stores the scaling coefficient correction.

9. The scaling correction logic further, The scaling factor correction is associated with the print medium identifier associated with the print medium, The system according to claim 8, wherein the scaling coefficient correction is stored and performed.

10. The scaling correction logic further, Receiving notification of a second print job to be printed on a second print medium, Extracting a second scaling factor correction based on the print medium identifier of the second print medium, The system according to claim 9, wherein the second scaling factor correction is applied to the print command associated with the second print job.

11. The system according to claim 1, wherein the scaling correction logic further generates an updated scaling factor correction based on the average of a first page scaling factor based on the generated first and second surface scaling factors and a second page scaling factor based on the generated third and fourth surface scaling factors.

12. The system according to claim 1, further comprising one or more image capture devices for capturing images of the print job.

13. The system according to claim 1, further comprising one or more printers for printing the print job.

14. It is a method, To receive a first evaluation print image data associated with a test mark printed on a first side of a print medium based on a print job, and a second evaluation print image data associated with a test mark printed on a second side of the print medium, A first surface scaling coefficient is generated based on the first evaluation print image data, and a second surface scaling coefficient is generated based on the second evaluation print image data, A scaling coefficient correction is generated based on the first surface scaling coefficient and the second surface scaling coefficient that have been generated. Receiving a third evaluation print image data associated with a test mark printed on the printing medium from the first side of the second page image of the print job, and a fourth evaluation print image data associated with a test mark printed on the printing medium from the second side of the second page image, A third surface scaling coefficient is generated based on the third evaluation print image data, and a fourth surface scaling coefficient is generated based on the fourth evaluation print image data, The scaling coefficient correction is updated based on the generated third surface scaling coefficient and fourth surface scaling coefficient, The process involves determining whether the difference between the scaling coefficient correction before the update and the scaling coefficient correction after the update exceeds a predetermined threshold, A method comprising: generating an alert when it is determined that the difference exceeds a predetermined threshold.

15. The method according to claim 14, wherein a surface scaling factor is generated by comparing dimensions based on evaluation print image data with dimensions based on expected print image data expected from the print job.

16. The method according to claim 15, wherein a surface scaling coefficient is generated based on the expected print image data expected from the print job, which is included in the print command associated with the print job.

17. The method according to claim 15, wherein a surface scaling factor is generated by averaging two or more measured dimensions of the test marks.

18. The method according to claim 14, further comprising storing the scaling factor correction.

19. A computer-readable medium in which instructions are stored, wherein when an instruction is executed by one or more processors, the processors... To receive a first evaluation print image data associated with a test mark printed on a first side of a print medium based on a print job, and a second evaluation print image data associated with a test mark printed on a second side of the print medium, A first surface scaling coefficient is generated based on the first evaluation print image data, and a second surface scaling coefficient is generated based on the second evaluation print image data, A scaling coefficient correction is generated based on the first surface scaling coefficient and the second surface scaling coefficient that have been generated. Receiving a third evaluation print image data associated with a test mark printed on the printing medium from the first side of the second page image of the print job, and a fourth evaluation print image data associated with a test mark printed on the printing medium from the second side of the second page image, A third surface scaling coefficient is generated based on the third evaluation print image data, and a fourth surface scaling coefficient is generated based on the fourth evaluation print image data, The scaling coefficient correction is updated based on the generated third surface scaling coefficient and fourth surface scaling coefficient, The process involves determining whether the difference between the scaling coefficient correction before the update and the scaling coefficient correction after the update exceeds a predetermined threshold, A computer-readable medium that generates an alert and performs the following actions when it is determined that the difference exceeds the predetermined threshold.

20. A computer-readable medium according to claim 19, which generates a surface scaling factor by comparing dimensions based on evaluation print image data with dimensions based on expected print image data expected from the print job.

21. The computer-readable medium according to claim 20, which generates an area scaling factor based on the expected print image data expected from the print job, included in the print command associated with the print job.

22. The computer-readable medium according to claim 20, wherein a surface scaling factor is generated by averaging two or more measured dimensions of the test marks.

23. The computer-readable medium according to claim 19, wherein, when executed by one or more processors, it also stores instructions causing the processors to further store the scaling coefficient correction.

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