WO2022060368A1

WO2022060368A1 - Impression medias

Info

Publication number: WO2022060368A1
Application number: PCT/US2020/051756
Authority: WO
Inventors: Vered COHEN; Vitaly Portnoy; Yossi YAACOBOV; Eyal LOVTON; Yuval Kfir
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2020-09-21
Filing date: 2020-09-21
Publication date: 2022-03-24

Abstract

According to an example, a printing system comprises a transfer member, an impression member comprising a holder, and a controller. The controller may be to read performance data associated with an impression media attached to the impression member by the holder, determine a score of the impression media based on the performance data, and suggest a replacement if the score exceeds a threshold. The transfer member is to transfer printing fluid to a substrate when the substrate is moving between the transfer member and the impression member, the substrate to contact an external face of the impression media.

Description

IMPRESSION MEDIAS BACKGROUND [0001] Certain printing systems include a blanket or other transfer member and an impression member for conveying printing fluids to a substrate. Some such printing systems utilize a consumable impression media, to be positioned upon the impression member to enhance printer performance. BRIEF DESCRIPTION OF DRAWINGS [0002] Features of the present disclosure are illustrated by way of example and are not limited in the following figure(s), in which like numerals indicate like elements, in which: [0003] FIG.1 shows a printing system comprising a transfer member and an impression member, according to an example of the present disclosure; [0004] FIG.2 shows a printing system utilizing an impression media, according to an example of the present disclosure; [0005] FIG.3 shows a line chart representing a score of an impression media over a time period, according to an example of the present disclosure; [0006] FIG.4 shows a printing system comprising an intermediate transfer member and an impression cylinder, according to an example of the present disclosure; [0007] FIG.5 shows a method to determine a replacement of an impression media, according to an example of the present disclosure; [0008] FIG.6 shows a set of instructions stored in a computer-readable medium, according to an example of the present disclosure. DETAILED DESCRIPTION [0009] For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be readily apparent, however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure. [0010] Throughout the present disclosure, the terms "a" and "an" are intended to denote at least one of a particular element. As used herein, the term "includes" means includes but not limited to, the term "including" means including but not limited to. The term "based on" means based at least in part on. [0011] Disclosed herein are examples of printing systems, methods, and instructions which may be used to determine a score of an impression media. Hence, different examples of printing systems, methods, and sets of instructions are described. [0012] Printing devices and systems transfer a printing fluid from a fluid supply to a substrate in order to obtain a desired plot on the substrate. As used herein, “printing fluid” refers generally to any substance that can be applied upon a substrate by a printer during a printing operation, including but not limited to inks, electro-inks, primers and overcoat materials (such as a varnish), water, and solvents other than water. Depending on the technology used to transfer the printing fluid and the type of substrate, different pre-processing and post-processing stages have to be performed to obtain a standard image quality. [0013] Some printing technologies transfer printing fluid to a substrate by ejecting the printing fluid through a series of nozzles distributed in printheads. Afterward, in case that post-processing is required, further operations may be executed over the substrate. Other examples of printing technologies may comprise intermediate stages so as to obtain the desired plot on the substrate. Intermediate stages may comprise transferring the printing fluid to a transfer member which afterward transfers the printing fluid to the substrate. The transfer member may enable the printing system to improve the content characteristics of the plot without reducing the throughput of the printing operation. As used herein, the term “printing operation” refers generally to activities performed by a printing system. Examples of printing operations comprise executing a start-up routine in the printing system, transferring a printing fluid to a substrate, scanning information from a substrate, a print job receipt operation, a primer application operation, a drying operation, a duplexing operation, a printer calibration operation, or any other process taking place at the printer system that is to create, or to set up the printing system to create, a printed print job on a substrate. [0014] Examples of transfer members comprise printing image plates, printing blankets, transfer belts, transfer media, rotative drums having a transfer media in an external face, and other elements able to transfer printing fluid to a substrate. The geometry of a transfer member may be different depending on the printing system architecture so that to fulfill spacing requirements within the printing system. In the same way, external surfaces of transfer members may comprise planar surface or curved surfaces. [0015] When using transfer members, a printing fluid is transferred to a substrate that is contacting a surface of an impression member. In order to improve the transfer to the substrate, the impression member may comprise a corresponding geometry to the one that the transfer member has. For instance, when a transfer member is a transfer belt, the impression member may comprise a corresponding profile that enables a proper transfer of the printing fluid between the transfer member and the substrate, such as a cylindrical profile. [0016] In another example, the transfer member may be a transfer media and the impression member profile may correspond to a flat surface. This configuration enables an increase of a contacting area between the transfer media and the substrate. [0017] In some other examples, both the transfer member and the impression member may be cylindrical elements having a diameter. Depending on the printing system, the diameter of the transfer member and the print zone may be different in order to provide a transfer surface between the transfer member and the substrate disposed on the print zone. The cylindrical element that comprises the impression member along its perimeter may be alternatively referred to as impression cylinder. [0018] As used herein, the term “impression member” refers to a member of the printing system that is to support a substrate, wherein the substrate is to receive printing fluid from the transfer member. [0019] When using transfer members, impression medias may be used in the printing system to ensure an appropriate transfer between the transfer member and the substrate. These impression medias may be positioned between the impression member and the substrate in which the printing fluid is to be transferred (from an intermediate member or a series of printheads). In order to couple the impression media to the print zone, a series of holders may be distributed along the length of the print zone to engage with the lateral edges of the impression media. [0020] According to an example, an impression media may collect printing fluid during a printing operation. By collecting printing fluid, the printing fluid that has not been properly transferred to the substrate does not remain on the impression member. Instead, the printing fluid is absorbed by the impression media. Since a substrate width may not span all width of the transfer member, the impression media can collect printing fluid that is not transferred to the substrate. Depending on the type of substrate being used in the printing system, background printing fluid may be obtained also in printed areas (when transferring to textiles, for instance). In some examples, the type of substrate is associated with predetermined profiles such as rigid media, textile, paper, among others. [0021] As used herein, the term “background fluid” refers generally to a parameter related to the printing fluid that is collected by an impression media during a printing operation of the printing system. The parameter may be represented by an amount of printing fluid or a percentage. [0022] In other examples, the impression media may mitigate the impacts derived from a transfer between the transfer member and the substrate, for instance when having a transfer member or an impression member having a curved shape such as rigid drums or cylinders. As a result, the impression media may increase the lifespan of the elements of the printing system because transfer resulting forces are absorbed by the impression media and not by other elements. [0023] In some other examples, unexpected events may result in a lack of substrate in which printing fluid is to be transferred. These unexpected events cause an undesired transfer of printing fluid to the impression member, thereby generating an inconvenient scenario to continue the printing operation. Examples of unexpected events are a substrate jam caused by an external element blocking a substrate path or a substrate jam caused by a skew of the substrate. When having an impression media on the impression member, the printing fluid may be absorbed and the printing operation may continue without stopping the printing operation. [0024] However, the properties of an impression media may be affected upon a number of usages have been executed or an amount of printing fluid has been collected. In order to maintain the performance of the printing system, the impression media should be replaced for a new impression media to preserve the same performance during printing operations. An impression media may be determined to be worn out upon a number of printing operations have been performed, a number of unexpected events have happened, or reaching an amount of printing fluid absorbed by the impression media. In some examples, the number of printing operations, the number of unexpected events, and the printing fluid absorbed by the impression media are represented as parameters. [0025] As used herein, the term “impression media” comprises any media which can collect printing fluid. Some examples of impression media may include, paper, foams, or any absorbent material able to collect printing fluid. [0026] Referring now to FIG.1, a printing system 100 comprising a transfer member 110, an impression member 120, and a controller 130 is shown. The printing system 100 may be used to transfer a printing fluid to a substrate (not shown in FIG.1). The transfer member 110 may correspond to the examples previously described in the description such as a transfer media, a transfer belt, a blanket winded around a rotative drum or cylinder, among others. The impression member 120 may have a geometry so as to contact the transfer member 110 through the substrate while the substrate moves over the impression member 120. The substrate is to move between the transfer member 110 and the impression member 120. The impression member 120 comprises a holder 121, wherein the holder 121 engages an impression media (not shown in FIG.1) to a surface of the impression cylinder 120. As a result, the impression media remains attached on an external surface of the impression member 120 although the substrate is moving over the impression member 120. Hence, while printing fluid is being transferred to the substrate while moving between the transfer member 110 and the impression member 120, the substrate contacts an external face of the impression media. As previously described, the presence of the impression media may improve the transfer to the substrate while preventing damage over elements belonging to the printing system 100. [0027] The printing system 100 further comprises the controller 130, wherein the controller is to read performance data 131 associated with the impression media. Examples of performance data 131 associated with the impression media comprise a number of previous printing operations, a number of unexpected events, historical data about the previous printing operations, an overall density of the previous printing operations, overall printing speed for the printing operations, among others. The performance data 131 may be stored in a readable medium of the printing system 100 or a different location such as a processor readable medium, a server, a computing device, among others. The controller 130, based on the performance data 131, is to determine a score of the impression media, wherein the score is a value that characterizes a series of conditions of the impression media. The controller 130 is further to suggest a replacement of the impression media if the score exceeds a threshold. [0028] In some examples, read the performance data 131 associated with the impression media further comprises read substrate data associated with the substrate. The controller 130 may be further to determine the threshold based on the substrate data. [0029] According to some examples, the substrate data may correspond to experimental information extracted from a series of data points. Based on a series of results for the tested substrates, the threshold may be determined so as to provide an accurate timing for the replacements of the impression media. [0030] In other examples, the substrate data may comprise at least one of a density of the substrate that is to contact the external face of the impression media, a type of substrate, a substrate stiffness grade, a substrate porosity, and a substrate thickness. Depending on the type of substrate (for instance textile substrates, paper substrate, cardboard substrate, or rigid substrates), the threshold may be set based on information about the type of substrate stored in a readable medium. In the same way, substrates having different substrate thicknesses may be associated with different thresholds. In some examples, a user may input to the printing system 100 a substrate data in which the user inserts any parameter that the user has available (for instance the substrate thickness, type of media, porosity of the substrate, stiffness or the substrate density). [0031] Referring now to FIG.2, a printing system 200 utilizing an impression media 222 is shown. The printing system 200 comprises a transfer member 210 and an impression member 220 having a cylindrical shape. The impression member 220 may be alternatively referred to as impression cylinder. As previously described in reference to FIG.1, the impression member 220 comprises holders 221 to engage the impression media 222 to an external surface of the impression member 220. The transfer member 210 is to transfer a printing fluid to a substrate 240, wherein the substrate is to move between the transfer member 210 and the impression member 220. In order to show the different elements of the printing system 200 the substrate 240 has been represented as a flat surface while moving between the transfer member 210 and the impression member 220. However, it should be noted that in other examples the substrate 240 may be bent while moving between the members. [0032] As previously described in the examples of FIG.1, the transfer member 210 transfers printing fluid to the substrate 240 while an external face of the impression media 222 is contacting a bottom face of the substrate 240. In some examples, the transfer member 210 comprises a blanket to receive printing fluid from a third member, for instance a photoconductor, and in turn transfer some or all of the print fluid to a substrate moving over the impression member 220. The presence of the impression media 222 provides a better transfer of printing fluid between the transfer member 210 and the substrate 240. However, when a number of printing operations have been performed in the printing system 200 with the same impression media, the mechanical properties of the impression media 240 may be reduced. [0033] Examples of impression media characteristics affected by the number of printing operations are the thickness of the impression media 222 and the absorption of the impression media 222. A reduction in the thickness of the impression media 222 may cause that the transfer of printing fluid is performed with a lower contact surface between the transfer member 210 and the substrate 240. [0034] The printing system 200 further comprises a controller (not shown in FIG.2), wherein the controller is to read from a readable medium performance data 231 associated with the substrate 240 and substrate data 236 associated with the impression media 222. The controller, based on the performance data 231 and the substrate data 236, may determine a score for the impression media 222 and a threshold. In order to calculate the threshold, the controller reads from the substrate data 236 information regarding the substrate 240 and calculates a threshold value for the impression media 222. In order to calculate the score, the controller reads from the performance data 231 information regarding the impression media 222, as previously explained in the description. The performance data 231 comprises data regarding background fluid 231a, printing operations 231b, and unexpected events 231c. [0035] The background fluid 231a refers to a value of background fluid that is collected by the impression media 222. In case that substrate 240 is not covering a width of the impression media 222, a non-substrate area may receive printing fluid. Furthermore, when using a type of substrate 240 that allows the penetration of fluids through its surface, the impression media 222 may collect the remaining fluid that has not been transferred to the substrate 240. Examples of substrate 240 that may allow the penetration of printing fluids are textiles and substrates with high porosity. In some examples, the background fluid 231a is determined based on the printing operation that the printing system 200 is to perform. A processor may forecast a value of background fluid collected by the impression media for the printing operation based on the content of the printing operation. In other examples, the background fluid 231a is determined as a difference between an expected weight of the substrate 240 after a printing operation and an actual weight of the substrate 240. In some other examples, the background fluid 231a may be determined by using optical sensors of the printing system 200. [0036] The printing operations 231b refers to information about the previous printing operations performed by the printing system 200 since an installation of the impression media 222. Because of friction and abrasion between the substrate 240 and the impression media 222, the usage of the impression media is related to its capabilities to hold (and collect) printing fluid. In some examples, the information about printing operations comprises operation time since the installation, a number of revolutions performed by the impression member 220 since the installation, a time elapsed since the installation, among others. In other examples, the information about the previous printing operations may further comprise information about previous installations, i.e. historical data of previous impression medias. [0037] The unexpected events 231c refers to information about unexpected events, such as substrate jams, experienced by the printing system 200 since an installation of the impression media 222. A substrate jam may cause that printing fluid is transferred to the impression media 222 instead of the substrate 240, and therefore, the impression media 222 collects that printing fluid. In some examples, the substrate jams are associated with an amount of printing fluid expected to be collected by the impression media 222. Depending on the width of the transfer member 210, the amount of printing fluid expected to be collected by the impression media 222 may change. In some other examples, a speed of the printing operation or an overall density of the printing operation may be associated with an amount of printing fluid expected to be collected by the impression media when experiencing a substrate jam. Substrate jams may be caused by a misalignment of the substrate compared with a substrate path direction, a subelement of the printing system blocking a substate path direction, among others. [0038] The printing system 200 may determine a score of the impression media 222 based on the performance data 231, wherein the performance data 231 associated with the impression media 222 comprises a parameter associated with the background fluid 231a, a parameter associated with the printing operations 231b, and a parameter associated with the substrate jams 231c. In case that the score of the impression media 222 exceeds the threshold value, a replacement of the impression media 222 is suggested by the printing system 200. [0039] In other examples, the substrate data 236 may not be available and a predefined threshold is set for the impression media 222. [0040] According to an example, the score of the impression media 222 may be determined by weighting by factors each of the value of background fluid collected, the number of printing operations, and the number of unexpected events. In an example, each of the background fluid, the printing operations, and the unexpected events is represented by a first parameter, a second parameter, and a third parameter, respectively. Hence, for example, the score may award with a higher weight the unexpected events 231c compared with the background fluid 231a. In other examples, the factors are set based on a lifecycle of the impression media 222. [0041] According to other examples, the factors are based on printing system characteristics. The printing system characteristics may comprise at least one of a type of printing system 200, a quality setting of the printing operations, an average density of the print plots, a width of the transfer member 210, a porosity of the substrate, and an average printing speed of the printing operations. Examples of types of printing system 200 comprise transfer members having an architecture based on belts, transfer members having a cylindrical shape, and transfer members presented in the form of a transfer media. [0042] Referring now to FIG.3, a line chart 300 representing a score 340 of an impression media over a time period is shown. In an example, the impression media corresponds to the impression media 222 previously explained in FIG.2. The X-axis of the line chart 300 represents a time and the Y-axis represents scores of the impression media at different times. A threshold 350 is set for the impression media, wherein the threshold may be set as a predefined value or may be based on substrate date if available, as explained above. The score 340 results from the aggregation of a first parameter 310, a second parameter 320, and a third parameter 330. However, in other examples, the score 340 may comprise further parameters. In the example of FIG.3, the first parameter is associated with background fluid collected by the impression media, the second parameter is associated with an aging factor related to the printing operations, and the third parameter is associated with the unexpected events experienced by the printing system. The parameters may be stored as performance data, wherein the performance data is being updated based on the printing operation performed by the printing system. In an example, the first parameter 310 corresponds to the parameter of background fluid 231a of FIG.2, the second parameter 320 corresponds to the parameter of printing operations 231b, and the third parameter 330 corresponds to the parameter of unexpected events 231c of FIG.2. [0043] As previously described, each of the parameters may be weighted by a factor. However, in order to simplify the explanation, in the example of FIG.3 each of the first parameter 310, the second parameter 320 and the third parameter 330 contribute equally to the score 340. In other examples, the factors that weight the parameters may be based on printing system characteristics, as previously described in the description. In some other examples, the factors may be applied to the parameters based on at least one of the printing operation information and the printing system information. In an example, factors applied to the parameters are based on a speed range of the printing operation, an age stage of the impression media, and historical data of the printing system. Depending on the speed of the printing operation, parameters associated with unexpected events, such as substrate jams or external elements blocking the substrate path, may have a greater contribution to the score. In the same way, at later age stages of the impression media, the background fluid parameter may have a greater impact than in earlier age stages of the impression media. In some examples, the factors may be stored in a database. A controller may access the database so as to obtain the factors to be used in the printing system. In other examples, the factors may be stored in a computer readable medium of the printing system. [0044] In the example of FIG.3, the first parameter 310 and the second parameter 320 are having a slope and the third parameter 330 experiences a first increase at a time 301 and a second increase at a time 303. At a time 302, the slope of the first parameter 310 increases. The increase of the slope may be caused because of a new stage of the lifecycle of the impression media, as described previously in the description. In other examples, the first parameter 310 may not have different stages within the lifecycle. The first and second increases of the third parameter 330 may be associated with an unexpected event in the printing operation. Each unexpected event may be associated with a fixed contribution in the third parameter 330. In other examples, the contribution may be determined based on measurements of the unexpected event determined by the printing system. [0045] At a time 351, the score 340 intersects the threshold 350, and therefore, a replacement of the impression media is suggested to a user of the printing system. In case of having available an automatic replacement of the impression media in the printing system, a replacement operation may be executed upon the score 340 exceeds the threshold 350. In other examples, a notification is triggered upon the score 340 exceeds the threshold 350 by using a display of the printing system. In some other examples, an instruction is sent to a user regarding a replacement of the impression media upon the score 340 exceeds the threshold 350. Upon the impression media is replaced, the performance data associated with the previous impression media is reset. However, in some examples, some historical information may be stored for future impression medias, as previously explained in reference with other examples. [0046] Although in FIG.3 each of the first parameter 310 and the second parameter 320 are represented by linear functions and the third parameter 330 is represented by a step function, it should be noted that other examples may comprise different functions rather than linear functions or constant values, for instance, non-linear functions or simulation functions determined by empiric information determined during testing. Furthermore, even though there are no changes in the slope of the second parameter 320 or the increase of the third parameter 330, other examples may comprise different slopes for the second parameter 320 and/or different increases for the third parameter 330. [0047] According to some examples, the parameters may be a value, a number, or a percentage. Hence, referring back to FIG.3 the first parameter the first parameter 310 may be an amount of background fluid collected by the impression media, the second parameter 320 may be a number of printing operations executed with the same impression media, and the third parameter 330 may be a number of unexpected events experienced by the printing system. In other examples, the parameters may be represented by percentages of contribution of a total amount, i.e., the status of the parameter when being compared with a reference value. [0048] Referring now to FIG.4, a printing system 400 comprising an intermediate transfer member 410 and an impression cylinder 420 is shown. The intermediate transfer member 410 and the impression cylinder 420 may correspond to one of the examples previously explained in reference with FIGs.1 and 2. The printing system 400 further comprises a rotative drum 430 comprising a printing image plate 431 in which a latent image is to be written by an emitter 440. The image plate 431 may be negatively charged by a series of chargers on a surface of the rotative drum 430. Afterward, the image plate 431 is charged by the laser beam generated by the emitter 440 in order to write the latent image. A series of electro-inks 450 may sequentially engage with the printing image plate 431 while the rotative drum 430 rotates. As a result of the charge difference within the image plate 431, electro-inks are transferred to the desired areas. [0049] Once the image plate 431 receives the electro-inks, the printing fluid is transferred to an external surface of the intermediate transfer member 410. Since both the rotative drum 430 and the intermediate transfer member 410 are having a cylindrical shape, the content is transferred from the printing image plate 431 to the intermediate transfer member 410. Subsequently, the electro-ink is transferred from the intermediate transfer member 410 to a substrate 440 moving over the impression cylinder 420. The impression cylinder 420, as previously described in other examples, may comprise holders to receive an impression media (not shown in FIG.4). The impression media may contact the substrate 440, and may be replaced upon a score of the impression media exceeds a threshold value (as shown in FIG.3). When the score is exceeding the threshold, a processor (not shown in FIG.4) may send a notification to a user of the printing system 400 indicating that a replacement of the impression media is needed. In case of having available an automatic replacement, a replacement operation may be triggered based on the notification. In other examples, a photoconductor may be attached to a surface of the rotative drum 430 and a blanket may be attached to the transfer member 410, wherein the rotative drum 430 and the transfer member 410 are arranged such that the photoconductor and the blanket are each rotate and abut one another throughout the rotations. [0050] According to some examples, the intermediate transfer member 410 comprises a blanket attached along its surface. In order to improve the transfer to the substrate 440, the blanket may be heated until a target temperature is obtained. Performing the transfer when having a heated blanket enhances the transfer of the printing fluid to the substrate 440. [0051] As explained previously in FIG.3, the score of the impression media of the printing system 400 of FIG.4 may be reset upon a replacement of the impression media is performed. The replacement may be indicated to the printing system 400 by selecting a prompt shown in a display of the printing system 400. In other examples, an optical sensor may determine a temporary absence of impression media and subsequent installation of a new impression media. In case that a user notices that the condition of the impression media is better than expected, the user may indicate to the printing system 400 that the factors may not be accurate. The printing system 400 may modify the contribution of performance data and its parameters to the score based on a visual inspection of the impression media performed by the user or an external device. [0052] Referring now to FIG.5, a method 500 to determine a replacement of the impression media is shown. The method may be used to determine a condition of an impression media, wherein the condition is determined by performing a comparison between a score and a threshold value. The method 500 comprises: reading performance data associated with an impression media 510, determining a score based on the performance data 520, comparing the score with a threshold value 530, and triggering a notification if the score exceeds the threshold value. The performance data associated with the impression media is updated during a printing operation. As previously explained in reference with FIGs.1 to 4, the printing operation comprises transferring printing fluid to a substrate contacting the impression media printing fluid is transferred to a substrate contacting the impression media. In an example, the performance data associated with the impression media corresponds to the performance data 231 previously explained in FIG.2. In other examples, the performance data associated with the impression media comprises information about printing operations performed since an installation of the impression media, such as a number of printing operations since the installation, a background fluid value for the printing operations since the installation, and a number of unexpected events experienced since the installation. In other examples, the information about the printing operations may further comprise a printing speed of the printing operations and a type of printing operation. [0053] In an example, the method 500 may further comprise determining the threshold value based on substrate characteristics such as the substrate data 236 of FIG.2. The substrate characteristics may comprise at least one of a thickness of the substrate, a density of the substrate, and a width of the substrate. In other examples, the substrate characteristics may further comprise a porosity of the substrate and a type of substrate. The type of substrate may be defined as a series of predefined profiles of substrate: rigid media, textile, paper, among others. In some other examples, custom substrate profiles may be available for the printing system and a user may select one of them through the printing system. As a result, a series of thresholds for custom substrate profiles may be assigned based on the selection. In further examples, in case that the substrate characteristics are not available, the threshold value may be assigned to a predefined threshold assigned to the printing system. [0054] In other examples, the performance data associated with the impression media is weighted by a series of factors, wherein each factor of the series of factors is applied over the data associated with the impression media. These factors, as previously explained in reference with FIG.3, may be set based on printing system characteristics such as a type of printing system, a quality setting of the printing operations, and an average printing speed of the printing operations. In an example, the factors are based on a speed range of the printing operation, an age stage of the impression media, and historical data of the printing system. While performing printing operations at a high speed, parameters such as unexpected events have a greater impact on the score compared with a lower speed range. In the same way, the age stage of the impression media may have an impact on the capabilities to collect printing fluid, and therefore, depending on the age stage, the factor applied to the background fluid may be different. Historical data of the printing system may correct the factors previously applied to the parameters. In case that users notice, by themselves or through an external device, that an impression media that is to be replaced is still in a good condition, this correction is stored within the historical data for future calculations. The correction may be applied, for instance, to the factors weighting each of the parameters. [0055] Referring now to FIG.6, a set of instructions 600 is shown. A computer- readable medium (not shown in FIG.6) may comprise the set of instructions 600, and when the set of instructions 600 are executed by a processor (not shown in FIG. 6), cause a printing system to: read performance data of the printing system since an installation of an impression media 610, calculate a score based on the performance data of the printing system 620, and suggest a replacement of the impression media if the score exceeds a threshold value 630. The performance data comprises a number of printing operations performed with the impression media and an operation time since the installation of the impression media. As previously explained in the description, printing fluid is to be transferred to a substrate contacting an external face of the impression media. In other examples, performance data may be the performance data 231 previously explained in FIG.2. [0056] According to some examples, the performance data further comprises a number of unexpected events experienced by the printing system since the installation of the impression media. In other examples, the data included in the performance data is weighted by a series of factors, as previously explained in FIG. 3. [0057] In some examples, the threshold value may be determined based on substrate data. Substrate data may comprise a type of substrate to be used by the printing system, a thickness of the substrate, a width of the substrate, among others. As previously explained in reference with FIG.5, custom substrate profiles may be associated with a series of thresholds value. [0058] In some other examples, in case that a replacement of the impression media is performed, the set of instructions 600 comprises further instructions to reset the performance data of the impression media. However, the performance data associated with impression medias that has been replaced may be stored in a database in order to improve the usage determination of both the threshold and the score. [0059] According to some other examples, a computer-readable medium may comprise instructions, that when executed by a processor, cause a printing system to perform a method such as the method 500 previously described in FIG.5. The printing system may be one of the examples previously explained in FIGs.1, 2 and 4 and a determination of a score over a time period may be represented by the line chart 300 of FIG.3. In other examples, the printing system further comprises the computer-readable medium having the instructions. [0060] Examples of computer-readable medium comprise any non-transitory tangible medium that can embody, contain, store, or maintain instructions for use by a processor. Computer readable media include, for example, electronic, magnetic, optical, electromagnetic, or semiconductor media. More specific examples of suitable computer readable media include a hard drive, a random-access memory (RAM), a read-only memory (ROM), memory cards and sticks, and other portable storage devices. [0061] What has been described and illustrated herein are examples of the disclosure along with some variations. The terms, descriptions, and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the scope of the disclosure, which is intended to be defined by the following claims (and their equivalents) in which all terms are meant in their broadest reasonable sense unless otherwise indicated.

Claims

CLAIMS: What is claimed is: 1. A printing system comprising: a transfer member; an impression member comprising a holder to engage with an impression media; and, a controller to: read performance data associated with the impression media; determine a score of the impression media based on the performance data; and, suggest a replacement if the score exceeds a threshold, wherein the transfer member is to transfer printing fluid to a substrate when the substrate is moving between the transfer member and the impression member, the substrate to contact an external face of the impression media.

2. A printing system as claimed in claim 1, wherein read the performance data associated with the impression media further comprises read substrate data associated with the substrate, the controller further to: determine the threshold based on the substrate data, wherein the substrate data comprises at least one of: a type of substrate; and, a substrate thickness.

3. A printing system as claimed in claim 1, wherein the performance data associated with the impression media comprises: a first parameter of background fluid collected; a second parameter of number of printing operations; and, a third parameter of number of unexpected events experienced by the printing system since an installation of the impression media.

4. A printing system as claimed in claim 3, wherein determine the score of the impression media based on the performance data comprises weighting by factors each of the first parameter, the second parameter, and the third parameter, wherein the factors are based on printing system characteristics.

5. A printing system as claimed in claim 4, wherein the printing system characteristics comprise at least one of: a type of printing system; a quality setting of the printing operations; and, an average printing speed of the printing operations.

6. A method comprising: reading performance data associated with an impression media of a printing system, the performance data being updated during a printing operation, wherein the printing operation comprises transferring printing fluid to a substrate contacting the impression media; determining a score of the impression media based on the data; comparing the score with a threshold value; and, triggering a notification if the score exceeds the threshold value, wherein the performance data associated with the impression media comprises information about printing operations performed since an installation of the impression media.

7. A method as claimed in claim 6, wherein the threshold value is determined based on substrate characteristics comprising at least one of: a thickness of the substrate; a density of the substrate; and, a width of the substrate.

8. A method as claimed in claim 6, wherein triggering a notification if the score exceeds the threshold comprises sending an instruction to a user regarding a replacement of the impression media.

9. A method as claimed in claim 6, wherein the information about printing operations comprises: a number of printing operations since the installation of the impression media; a background fluid collected by the impression media since the installation; and, a number of unexpected events experienced since the installation.

10. A method as claimed in claim 9, wherein the information about printing operations further comprises: a printing speed of the printing operations; and, a type of printing operations.

11. A method as claimed in claim 9, wherein the information about printing operations is weighted by a series of factors, wherein the factors are based on: a speed range of the printing operation; an age stage of the impression media; and, historical data of the printing system.

12. A computer-readable medium comprising instructions, that when executed by a processor, cause a printing system to: read performance data of the printing system since an installation of an impression media, wherein printing fluid is to be transferred to a substrate contacting an external face of the impression media; calculate a score based on the performance data of the printing system; and, suggest a replacement of the impression media if the score exceeds a threshold value, wherein the performance data comprises: a number of printing operations performed with the impression media; and, an operation time since the installation of the impression media.

13. A computer-readable medium as claimed in claim 12, wherein the replacement of the impression media resets the performance data of the impression media.

14. A computer-readable medium as claimed in claim 12, wherein the number of printing operations further comprises a background fluid information for the number of printing operations.

15. A computer-readable medium as claimed in claim 14, wherein the performance data further comprise a number of unexpected events experienced by the printing system since the installation of the impression media.