Printing devices are a class of device capable of forming markings, such as text, images, and/or objects, on print media. The markings formed on print media may be two-dimensional (2D) in form or they may be three-dimensional (3D) in form, such as part of a 3D printed object. The printing devices may use fluid-based compounds to form markings, such as may contain colorants, particles, and/or dyes, by way of illustration. Drying mechanisms may be used to remove fluids while leaving colorants, particles, dyes, and the like behind.
Various examples will be described below by referring to the following figures.
Reference is made in the following detailed description to accompanying drawings, which form a part hereof, wherein like numerals may designate like parts throughout that are corresponding and/or analogous. It will be appreciated that the figures have not necessarily been drawn to scale, such as for simplicity and/or clarity of illustration.
Some printing devices eject printing fluids onto print media to form markings (e.g., text, images, objects, etc.). Upon application to some print media, printing fluids may cause fibers to swell and/or otherwise become damaged resulting in media curl, cockle, and other like undesirable characteristics. Print media may be conditioned (e.g., stretched, heated, pressed, held, etc.) and dried using a drying and conditioning system. Through conditioning and drying, liquids may be removed from the print media and media curl and cockle mitigated, by way of example. The present description refers to the conditioning and drying of media (both singly and in combination) as “drying” for ease. Thus, reference to “drying” is intended to encompass conditioning unless expressly stated otherwise.
At times, drying of print media may result in over-dried print media. In a duplex print job example, by way of illustration, printing fluid may be applied to a first side of a print medium. Dry air may be blown on the first side to remove liquid from the surface of the medium as it advances past a duplex divert mechanism. A heated pressure roller may also be put into contact with the medium to further facilitate fluid removal. Upon passing the duplex divert mechanism, the medium may change direction and may be pulled back towards a duplex media path. Thus, drying and/or conditioning may occur from the print zone until the medium passes the duplex divert mechanism and then motion back past the duplex divert mechanism and to the duplex media path. If the medium is A4 size and traveling along the length of long dimension (297 mm), then an initial portion (e.g., the leading edge) of the medium may experience approximately 600 mm of drying (e.g., media motion in the first direction and then back towards the duplex media path). In contrast, on the second side of the print medium the corresponding initial portion (e.g., leading edge) of the medium may experience approximately 300 mm of drying. This unbalanced drying of surfaces and portions of print media may lead to undesirable output characteristics (e.g., media curl).
In another example, portions of a print job may have more printing fluid density than others. In such cases, standard drying and/or conditioning may be insufficient for the portions of the print media with densely deposited printing fluid; nevertheless, the standard drying and/or conditioning may lead to overdrying the other portions of the print media at which printing fluid has been less densely deposited.
With the foregoing examples in mind (by way of non-limiting illustration), the present description proposes dynamic media drying and/or conditioning based on parameters of a print job. Thus, for the case of a duplex print job, opposing surfaces of a print medium may be exposed to approximately equal amounts of drying energy. And for the case of a print medium with differing printing fluid densities, varying amounts of drying energy may be applied to sufficiently dry dense regions and avoid overdrying regions at which printing fluids are applied less densely.
Printing device 100 also has a controller 110. Controller 110 refers to a processing mechanism comprising a combination of hardware and/or software (but not software per se) capable of receiving instructions, such as in the form of signals or states, and executing the received instructions to enable functionality of the controller and/or other parts of the device (e.g., drying system 106). Example controllers include field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and general-purpose processing units, by way of non-limiting example.
Controller 110 may receive signals (e.g., comprising instructions or data packets corresponding to a print job, like print job 112) from externally to printing device 100 (e.g., from a host or client device). Controller 110 may then process the received signals in order to trigger operation by printing device 100. To illustrate, in an example, an external host device may transmit a print job (e.g., print job 112) to printing device 100. The print job may be stored in memory and/or may be interpreted to form markings on print media in media path 102. For instance, controller 110 may determine that the print job is a duplex print job (e.g., markings on both sides of the print media). Controller 110 may also determine that a portion of the print job corresponds to higher printing liquid density value than other portions of the print job. Duplex/simplex and printing liquid density value are referred to more generally herein by the term “parameters.” The term “parameter” refers to a characteristic of a print job, such as simplex or duplex, color or black and white, dots-per-inch (dpi), print speed, and the like. Additionally, parameters of a print job may include characteristics of a portion of the print job, such as indications of coverage for a particular medium of a multi-page print job (e.g., a printing liquid density value).
Based on parameters 114, controller 110 may alter the functionality of printing device 100, such as by selecting a directionality of a number of directionalities 108. For instance, controller 110 may select a drying zone (of a number of drying zones 104) to receive drying energy (e.g., directing drying energy from one drying zone to another, directing drying energy towards multiple drying zones concurrently, moving drying energy between different drying zones consecutively, etc.). During drying of print media, different variations of directionalities may be selected, such as to achieve desired drying of print media. Returning to the above example of a duplex A4 print job, based on parameters 114 of print job 112, controller 110 may select a drying zone after a divert mechanism and then direct drying energy away from the post-divert drying zone while the print medium changes direction and moves back into a duplex media path. Alternatively, controller 110 may not provide any drying energy to the post-divert drying zone but instead direct drying energy to a duplex drying zone and then after the print media passes back through the print zone, provide drying energy along a number of drying zones approximately a same size and/or duration as the duplex drying zone. By so doing, exposure to drying energy on one side of the print medium will approximate drying energy applied to the second side of the print medium.
In another example in which one side of a duplex print job has a higher printing liquid density value than the other side, controller 110 may select directionalities 108 of drying system 106 such that a portion of the print job with the higher printing liquid density value is exposed to comparably more drying energy (e.g., the length of a pre-divert drying zone, a post-divert drying zone, and/or a duplex drying zone) than the other side of the print medium (e.g., only a post-divert drying zone). Further, in some cases, controller 110 may be capable of providing more or less drying energy to particular sub-portions of a page of a print job based on parameters 114 (e.g., increasing or decreasing an amount of drying energy applied to print media).
Additionally, based on parameters 114 of print job 112, controller 110 may select a directionality of directionalities 108, which may include selecting a form of drying energy. In one case, this may include selecting a non-contact-based form of drying energy, and in another case, selecting a contact-based form of drying energy. Yet other cases may include selection of multiple forms of drying energy. For instance, for the example of a print job 112 with a high printing liquid density value, controller 110 may direct application of both non-contact-based drying energy (e.g., an air-based dryer) and contact-based drying energy (e.g., a heated pressure roller). The contact-based drying energy may help reduce cockle. By contrast, in some cases, contact-based drying energy may overdry media with low printing liquid density values. Additionally, some fluids may respond more favorably to different forms of drying energy and may thus be favored. Etc.
With the foregoing in mind, an example device (e.g., print printing device 100) may include a media path (e.g., media path 102), a drying system (e.g., drying system 106), and a controller (e.g., controller 110). The media path is divided into a plurality of distinct drying zones (e.g., drying zones 104). The drying system includes a plurality of directionalities (e.g., directionalities 108) with relation to the plurality of distinct drying zones. For instance, in one example, one directionality may correspond to one drying zone and/or one form of drying energy. But in other examples, multiple drying zones may correspond to one directionality. The controller is to select a directionality of the plurality of directionalities based on parameters (e.g., parameters 114) of a print job (e.g., print job 112).
Drying mechanism 222 also includes directionalities 208, illustrated as arrows radiating out from drying mechanism 222. In the case in which drying mechanism 222 includes an air-based dryer, directionalities 208 may include air conduits to direct heated and/or humidity-controlled air to a desired drying zone. The arrows refer to the directed heated and/or humidity-controlled air. In an example in which drying mechanism 222 includes an IR heater, the arrows radiating out from drying mechanism 222 refer to IR light being directed from a source towards desired drying zones. The arrows radiating from drying mechanism 222 refer to similar combinations of structure for other types of non-contact-based drying methods. In cases of contact-based drying, the arrows may represent the transmission of signals to control operation of the contact-based drying mechanisms. For instance, the signals may instruct a heated pressure roller to move into a position from which it may be able to apply heat and pressure to print media passing through a particular drying zone. An arrow is also included referring to air recirculation path 238. At times, there may be a desire to recycle air (such as to reduce an amount of energy to be applied to heat the air and/or to remove moisture from the air). Another arrow, referring to air 240, representing air that is external to printing device 100 is shown to indicate flow of air towards an air intake (in this case at a rear portion of printing device 200).
In operation, example printing device 200 may operate similarly to printing device 100 of
In some cases, the different distinct drying zones may have different respective sizes. For instance, in one example the a post-divert drying zone (e.g., post-divert drying zone 228) may be at least twice the length of a pre-divert drying zone (e.g., pre-divert drying zone 226).
Moving on to
If, however, printing device 300 receives a duplex print job, then as a medium passes divert 324 (illustrated with a solid line in a normal position and a dashed line in a duplex position) and movement of divert 324 to the duplex position (dashed line) the medium will change direction and engage the duplex portion of media path 302, as indicated by F and C and corresponding arrows. While on this portion of media path 302, drying and/or conditioning may be performed on media at duplex drying zone 332. Alternatively, such as in response to parameters of a print job, drying and conditioning may be disactivated at duplex drying zone 332.
Like the example printing device 200 of
It is noted that at times directional structures 348 may not be made up of independent air conduits. Indeed, gaps between physical structures of printing device 300 may form the physical structure used to direct drying energy towards drying zones. For instance, there may be an air gap between external surfaces of printing fluid reservoirs and surfaces of other internal components that may lead towards a gap between printhead 342 and a structural surface supporting media path 302, by way of illustration. A shutter (e.g., valve 344) may be used to open and close access to this example air gap. In this example, the structural surface supporting media path 302 may include perforations through which heated and/or dried air may travel into a desired drying zone (e.g., post-divert drying zone 328).
Valve 344 refers to a structural component comprising one or more physical components to regulate flow of drying energy towards drying zones. In one implementation in which drying mechanism 322 comprises an air-based dryer, valve 344 comprises a shutter including one or more openings to direct air towards selected directional structures of directional structures 348. The shutter may move in response to signals received from a controller of printing device 300 (e.g., based on parameters of a print job). Other valve mechanisms are also contemplated by claimed subject matter.
Examples in which drying mechanism 322 comprises an air-based dryer include an air intake 350 via which air may be received from external to printing device 300. Drying mechanism 322 may be in fluid communication with the environment surrounding printing device 300 via air intake 350. A mechanism, such as a fan may be part of air intake 350 to facilitate air capture and introduction.
Additionally, there may be a desire to reuse air already within printing device 300. Thus, an air recirculation path 338 may be included to direct heated air back into drying mechanism 322 for further use. Air in air recirculation path 338 may have been cooled, and thus drying mechanism 322 may warm it back up. Air in air recirculation path 338 may also be more humid than desirable. Thus, drying mechanism 322 may also act to remove humidity from air entering drying mechanism 322 from air recirculation path 338 and/or air intake 350, such as based on an internal humidity determination (e.g., as enabled by the controller and a humidity sensor).
It is to be understood that even though
With the foregoing in mind, in operation, printing device 300 may comprise a liquid ejection printing device (e.g., an inkjet printer) including a media path (e.g., media path 302), a plurality of distinct drying zones arranged along the media path, at least one drying mechanism (e.g., drying mechanism 322) and directional structures (e.g., directional structures 348) arranged between the at least one drying mechanism and the plurality of distinct drying zones, and a controller (e.g., controller 110 of
For instance, if the drying system of printing device 300 comprises an air-based dryer (e.g., drying mechanism 322) and directional structures (e.g., directional structures 348), the output of the air-based dryer is to be directed to the plurality of distinct drying zones via the directional structures based on the received parameters. The directional structures may include air conduits and a valve (e.g., valve 344) to direct air through one or more air conduits. And as discussed, above, the valve or valves may operate in response to signals received from the controller. Additionally, printing device 100 may further include an air intake (e.g., air intake 350) and an air recirculation path (e.g., air recirculation path 338). And the controller will pull air in via the air intake, such as in response to an internal humidity determination.
As discussed above, a number of physical components may operate together to provide drying energy to drying zones of a printing device. Such operation may be enabled by a controller, such as in response to implementing instructions stored in memory.
Method 400 also includes transmitting drying energy via the selected directionality towards the selected drying zone, as illustrated at block 404. Thus, if the controller selects an air-based dryer, then the dried air may be transmitted towards the selected drying zone; if the controller selected an IR dryer, then the IR light may be directed (e.g., using wave guides) towards the selected drying zone; if the controller selected a contact-based dryer (e.g., a heated pressure roller), then the contact-based dryer may be moved into position and instructed to provide the desired drying energy to the print media, etc. For instance, in response to the duplex print job parameter described in the preceding paragraph, the functionality described at block 404 may include operating a valve (e.g., valve 344 of
As described above, there may be a desire to dynamically direct drying energy to distinct drying zones along a media path. And the described drying system and drying mechanism along with corresponding directional structure and drying zones provides an approach for the desired dynamic drying energy direction.
It is noted that the foregoing description uses terms like “and/or,” “at least,” “one or more,” and other like open-ended terms in an abundance of caution. However, this is done without limitation. And unless expressly stated otherwise, singular terms (e.g., “a,” “an,” or “one” component) are not intended to restrict to only the singular case but are intended to encompass plural cases as well. Similarly, “or” is intended to be open-ended, unless stated otherwise, such that “A or B” may refer to A only, B only, and A and B.
References throughout this specification to one implementation, an implementation, one example, an example, and/or the like means that a particular feature, structure, characteristic, and/or the like described in relation to a particular implementation and/or example is included in at least one implementation and/or example of claimed subject matter. Thus, appearances of such phrases, for example, in various places throughout this specification are not necessarily intended to refer to the same implementation and/or example or to any one particular implementation and/or example. Furthermore, it is to be understood that particular features, structures, characteristics, and/or the like described are capable of being combined in various ways in one or more implementations and/or examples and, therefore, are within intended claim scope. In general, of course, as has always been the case for the specification of a patent application, these and other issues have a potential to vary in a particular context of usage. In other words, throughout the disclosure, particular context of description and/or usage provides helpful guidance regarding reasonable inferences to be drawn; however, likewise, “in this context” in general without further qualification refers to the context of the present disclosure.
For purposes of explanation, specifics, such as amounts, systems and/or configurations, as examples, were set forth. In other instances, well-known features were omitted and/or simplified so as not to obscure claimed subject matter. While certain features have been illustrated and/or described herein, many modifications, substitutions, changes and/or equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all modifications and/or changes as fall within claimed subject matter.
Filing Document | Filing Date | Country | Kind |
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PCT/US2020/015606 | 1/29/2020 | WO |