Inkjet printers use one or more printheads provided with a number of nozzles from which ink droplets are fired or ejected onto a media. The printer controls the firing of ink from the nozzles to create on the media a pattern of dots corresponding to the desired image. By controlling the timing, placement and volume of inkjet output droplets, reliable, repeatable character performance and graphic performance is achieved.
The accompanying drawings illustrate various embodiments and are a part of the specification. The illustrated embodiments are merely examples and do not limit the scope of the claims. Throughout the drawings, identical reference numbers designate similar, but not necessarily identical elements.
The same part numbers designate the same or similar parts throughout the figures.
The nozzles of an inkjet printhead are typically arranged in one or more linear arrays, with the length of the nozzle arrays impacting the size of a swath of ink that the printhead can lay down upon the media in a single pass. For purposes of this specification and the appended claims, a ‘swath size” means a measurement or estimate of the extent of the distribution of ink from a printhead or printheads onto a media. One approach to increasing the speed of inkjet printing is to utilize multiple printheads positioned on a single carriage, print bar or other printhead holding structure. In this manner, the nozzle arrays of the multiple printheads can be functionally combined to create a swath. This approach is sometimes referred to as ‘combined swath printing“.
Combined swath technology allows printing at advanced speeds relative to printing speeds experienced when printing at lesser swath sizes. However, increasing the number of printheads utilized increases the probability of a printhead failure. Possible printhead failures include dogging of nozzles due to dried ink or contaminants becoming lodged in the nozzle orifices, burnt resistors, and/or insufficient backpressure within the printhead. When a printhead failure occurs, the printing process for a print job can be unexpectedly interrupted and result in wasted supplies (e.g. ink and media associated with a cancelled print job), wasted time (e.g., time associated with repeating a print job), and/or missed delivery dates. Embodiments described below were developed in an effort to provide a method and a system to print in a recovery mode that allows continuing printing of a print job by a printer utilizing combined swath printing even when one or more printheads are failing. User satisfaction with combined swath printing is increased as users can schedule large print jobs with increased confidence that a print job may be completed notwithstanding the occurrence of a printhead failure.
The embodiments shown in the accompanying drawings and described below are non-limiting examples. Other embodiments are possible and nothing in the accompanying drawings or in this Detailed Description of Embodiments should be construed to limit the scope of the disclosure, which is defined in the Claims.
The following description is broken into sections. The first section, labeled “Components”, describes various physical and logical components utilized to implement various embodiments and environments in which the embodiments may be implemented. The second section, labeled as “Operation”, describes example embodiments of a method to print in a recovery mode. The third section, labeled “Examples”, describes examples of a recovery print mode, according to embodiments of the disclosure.
COMPONENTS:
General printing module 102 represents generally any combination of hardware and programming configured to cause first printing upon a media in response to a print job, applying ink upon a media utilizing a first row and a second row of printheads. As used in this specification and the appended claims, media means any object that can be printed upon, including but not limited to paper media. As used in this specification and the appended claims, “ink” means any fluid used for printing including but not limited to aqueous inks, solvent inks, UV-curable inks, dye sublimation inks and latex inks. As used in this specification and the appended claims, a “print job” means one or more images submitted to be printed. In examples, an image may be submitted to be printed as a document or file and in a variety of document and/or file formats. The print job may be received utilizing a networking protocol, including but not limited to Transmission Control Protocol/Internet Protocol (“TCP/IP”), HyperText Transfer Protocol (“HTTP”), Simple Mail Transfer Protocol (“SMTP”), Extensible Messaging and Presence Protocol (“XMPP”) and/or Session Initiation Protocol (“SIP”). In examples, the sending computing device may be desktop, laptop, or mobile computing device that is connected to the web, the sending initiated by a user at a user interface included in such device. In another example, the print job may originate at a web enabled printer. For example, a user may send a print job via a printer application accessible at a control panel of a first web enabled printer, which results in the print job being received at the general printing module 102.
The print job is caused to print utilizing a first and a second row of printheads. The first row of printheads includes a plurality of printhead types. The second row of printheads is adjacent to the first row, and includes at least one printhead of each of the types present in the first row. In an embodiment, the first and second rows of printheads are located on a same printhead holding structure. In an embodiment, the holding structure that holds the first and second rows of printheads is a printhead carriage movably mounted on a slider rod and configured to move across a media during a printing operation. In another embodiment, the holding structure that holds the first and second rows of printheads is a stationary print bar. In an embodiment, the holding structure may include a page-wide-array configuration of printheads, wherein the printheads may be configured to span an entire media width during a printhead carriage across media, or pass of the media beneath a stationary print bar.
For purposes of this specification and the appended claims, a printhead “type” means a category or kind of printhead that has a readily defined characteristic. In a first example, a color inkjet printer may be provided with a plurality of printheads, with each printhead emitting one of the colors black, cyan, yellow, or magenta. It can be said in this example that the black, cyan, yellow, and magenta printheads are each a different “type” of printhead. In another embodiment of an inkjet printer, a printhead type may include a printhead that emits a specific combination of colors. In a second example a first printhead type that emits cyan and black, a second printhead type that emits magenta and yellow, and a third printhead type that emits light cyan and light magenta. In this second example, each of the cyan/black, magenta/yellow and light cyan/light magenta printheads is a different “type” printhead. Thus, in embodiments each of the printhead types included in the first and second rows emits ink of a different color, or combination of colors. In an embodiment, each of the printhead types included in the first and second rows emits ink of a different color, or combination of colors. In other embodiments, the type of printhead is characterized by a printhead feature or attribute other than colors emitted, including, but not limited to the number of nozzles or nozzle arrays, the length of nozzle arrays, and nozzle diameters.
In an embodiment, the second row of printheads includes printheads that are arranged in the same order as the printheads of the first row, according to type of printhead. For example, if the printheads in the first row are in the type order of “black, cyan, yellow, magenta” viewed left to right, the black, cyan, yellow and magenta type printheads of the second row are likewise positioned in the type order “black, cyan, yellow, magenta” viewed left to right. In an embodiment, the printheads are positioned on the holding structure such that the nozzle arrays of printheads of the first row overlap with nozzle arrays of a same type printheads in the second row, thereby allowing for the functional combination of multiple printheads of the same type during printing.
Detection module 104 represents generally any combination of hardware and programming configured to detect failure of a first printhead within the first row. For purposes of this specification and the appended claims, a “failure” means an inability to meet a performance standard. “Failure”, “failed”, and “inoperable” are used synonymously in this application. Detecting a failure may comprise utilizing nozzle health information gathered from a sensing device 112 included within the printer. In an embodiment, the detection module connects to a sensing device 112, and the detection module is operable to receive information from the sensing device 112 identifying blocked nozzles within a printhead.
In an embodiment, the sensing device 112 includes a drop detector. As used in this specification, “drop detector” means a device that is operable to detect the presence or size or quantity of drops of ink or other liquid. In an embodiment, the drop detector may employ piezo-electric material and associated circuitry which detects the impact of the ink drops hitting the detection station and thereby detects the ejection of ink drops from a printhead. In an embodiment, the drop detector may be an optical detector that includes a light source and a light detector. An inkjet nozzle may be aimed so that the ink drops pass between the light source and the light detector and occlude light rays that travel between the light source and the detector. In an embodiment, the drop detector is an electrostatic drop detector. In an example, the electrostatic drop detector may be configured such that as the printhead fires ink drops, a charge plate at the top of the sensor assembly induces an electrostatic charge in the drops. When charged drops fly past the sensor the drops induce an electrical charge on the sensor. Condition of the printhead nozzles, e.g., healthy or missing, may be determined by detecting the charges of the drops. In an embodiment, the sensing device 112 may be a sensor configured to detect ink pressure levels within components of a printhead, allowing for identification of blocked nozzles and other determinations of printhead condition.
Printhead status module 106 represents generally any combination of hardware and programming configured to analyze status of printheads included within the second row. In an embodiment, analysis of the status of the second row printheads is performed utilizing the same sensing device 112 or devices that communicated information to detection module 104. In other embodiments, a different sensing device or different set of devices may be utilized to analyze the second row printheads than the sensing device or devices utilized to detect the failed printhead in the first row. For example, status of the second row printheads may be analyzed utilizing a plurality of sensing devices, each to measure ink pressure level within a specific printhead, wherein the sensing device utilized to detect failures within the first row of printheads is a drop detector.
In an embodiment, recovery mode manager includes an exchange module 108. Exchange module 108 represents generally any combination of hardware and programming configured to cause an exchange of a second printhead in the second row and a third printhead in the first row in response to detecting the second printhead is failed and that the third printhead is healthy and of the same type as the second printhead. For purposes of this specification and the appended claims, “healthy” means meeting a performance standard. “Healthy”, “operable”, and “operating' are used synonymously in this application. The combination of the functionality of the detection module 104, printhead status module 106 and exchange module 108 affords an ability to complete a print job in a recovery mode that utilizes the second row, despite the fact that there was a printhead failure within the first row (the first printhead) and the second row (the second printhead). Exchanging the failed printhead in the second row with a healthy like kind printhead from the first row enables recovery mode printing to take place by rending all of the printheads in the second row operable to complete the print job. In an embodiment, detecting the second printhead is failed and that the third printhead is healthy and of the same type as the second printhead may utilize the same sensing device 112 or devices that communicated information to detection module 104 and/or the printhead status module. In an embodiment, the exchange may be caused by sending an instruction to a user via a display device, the instruction detailing the printhead exchange to be made. In another embodiment, the exchange may be caused to occur automatically, via the exchange module communicating with and/or acting in concert with a printhead exchange mechanism that automatically exchanges the second and third printheads.
Recovery printing module 110 represents generally any combination of hardware and programming configured to cause second printing upon the media to continue printing of the print job, utilizing the second row of printheads, and not the first row, in response to determining that printheads within the second row are operable to complete the print job. In an embodiment, determining that printheads within the second row are operable to complete the print job comprises determining that the second row has no inoperable printheads. In another embodiment, determining that the printheads within the second row are operable to complete the print job includes determining that the second row has operating printheads including at least one of each of the types. In an example, if the print job is a color print job and the first and second rows of printheads each contain one “cyan” type printhead, one “yellow” type printhead, and one “magenta” type printhead, the recovery printing module may confirm that each of the cyan, yellow, and magenta printheads are operable prior to completing the print job. In another embodiment, it may be determined that the printheads within the second row are operable to complete the print job notwithstanding that there is an inoperable printhead. For example, the second row of printheads may be operable for printing the print job notwithstanding a failure of a “cyan” printhead if cyan ink is not needed for the print job, or if there is more than one cyan printhead in the second row.
In an embodiment, a message is displayed to warn a user of a printhead failure and invite the user to choose among presented choices, including a choice to continue printing with operable printheads, upon detection of a printhead failure. As used in this specification a “display” may be a visual display, such as display via a monitor, projector, or other visual display device, and an auditory display of speech or non-speech output via an auditory display device. In embodiments, the presented choices may include a choice to stop printing, a choice to continue printing in the original mode notwithstanding the printhead failure, and a choice to continue printing utilizing the printheads in the second row and not the printheads in the first row. In an embodiment, printing may pause during the display of the message, and resumes when an instruction to continue printing with the operable printheads is received from a user. The instruction may be received via a user interface device such as a computer keyboard, mouse or touchpad.
In embodiments, the printheads in the first row continue to expel ink away from the media while the second row of printheads is being used in the second printing applying ink to the media to complete the print job. In such embodiments, a message may be displayed that warns a user that the choice to continue printing of the print job by applying ink to the media with less than all of the printheads can result in increased ink consumption as compared to normal printing using all printheads.
In an embodiment, the first printing and the second printing are both conducted utilizing a first plot calculated for the print job using the first printing. As used in this specification and the appended claims, a “plot” is a representation of an image converted to programming language and/or numerical form so that it can be stored and used in computing devices, servers, printers and other machines capable of performing calculations and manipulating data. As used in this specification and the appended claims, an “image” is a visual representation of an object, scene, person or abstraction (including text). The plot may include instructions as to how the image is to be printed. In embodiments, a plot may be expressed in a number of various languages and formats, including but not limited to HPGL/2 (Hewlett-Packard Graphics Language 2), PostScript, PDF (Portable Document Format), JPEG (Joint Photographic Experts Group standard), TIFF (Tagged Image File Format) and PCL3 (Printer Command Language 3).
In another embodiment, the first printing is conducted utilizing a first plot calculated for the first printing of the print job, and the second printing is conducted utilizing a second plot calculated for the second printing. In an embodiment, calculation of the second plot is caused to occur at a raster image processing component within the printer. In another embodiment, calculation of the second plot is caused to occur at a computing device, e.g., a printer management server, distinct from the printer.
Recovery mode manager 100 may be implemented in a number of environments, such as environment 200 of
Host computing device 202 represents generally any computing device capable of sending network requests to and otherwise communicating with printer 204. Host computing device 202 is capable of sending print jobs to and receiving information relating to the received print jobs and the printed output from, printer 204. Example implementations of host computing device 202 include a desktop computer, laptop computer, digital tablet computer, and the like.
Computing device 202 and printer 204 are interconnected via link 206. Link 206 represents generally one or more of a cable, wireless, fiber optic, or remote connection via a telecommunication link, an infrared link, a radio frequency link, or any other connectors or systems that provide electronic communication. Link 206 may include, at least in part, an intranet, the internet, or a combination of both. Link 206 may also include intermediate proxies, routers, switches, load balancers, and the like. The paths followed by link 206 between computing devices 202, and printer 204 as depicted in
Printer 204 represents generally any computing device operable to receive and process responses to requests to print content from host computing device 202 and to produce printed output. Printer 204 is capable of receiving print jobs from host computing device 202, and communicating information relating to the received print jobs and/or the printed output back to the host computing device 202. Printer 204 is shown to include a raster image processing component 208, media handling component 210, a print component 212, a recovery mode component 214, a finishing component 216, a service component 218, and a controller 220.
Returning to example printer 204, raster image processing component 208 represents generally any combination of hardware and software capable of converting digital information about fonts and graphics that describes the appearance of a desired image (e.g. information from a drawing or desktop publishing application) and translating that information into a plot composed of individual dots that printer 204 can output. In embodiments, a raster image processing component 208 composes a page layout. Media handling component 210 represents generally any combination of hardware and programming capable of transporting media through the printer 204. The media may be supplied for printing via a media roll, the media roll positioned within, or adjacent, to a housing of printer 204 during printing operations. Print component 212 represents generally any combination of elements capable of being utilized to form desired images on media. In a given example, print component 212 may include a fluid ejection mechanism, each fluid ejection mechanism including multiple printheads configured to dispense ink or other fluid. As used in this specification and the appended claims, “printhead” includes a mechanism having a plurality of nozzles through which ink or other fluid is ejected. Examples of printheads are drop-on-demand inkjet printheads, thermo resistive printheads, piezo and resistive printheads. Some printheads may be part of a cartridge which also stores the fluid to be dispensed. Other printheads are standalone and are supplied with fluid by an off-axis ink supply. Finishing component 216 represents generally any combination of hardware and programming capable of performing a finishing operation on media Such finishing operations include cutting, folding, laminating or any other action that affects the physical nature of the media. Service component 218 represents generally any combination of elements capable of being utilized to service print component 42. In an example, service component 218 may be configured to function as a spittoon and an alignment calibrator to service printheads.
Recovery mode component 214 represents generally any programming, that, when executed, implements the functionality of the recovery mode manager 100 of
In an embodiment, recovery mode component 214 is additionally configured to cause an exchange of a second printhead in the second row and a third printhead in the first row in response to detecting the second printhead is failed and that the third printhead is healthy and of the same type as the second printhead. Such an exchange can enable recovery mode printing to take place even in a situation where it is initially detected that the second row includes an inoperable printhead, by subsequently rendering the second row of printheads operable to complete the print job.
As used in this specification, controller 220 represents generally any combination of elements capable of coordinating the operation of components 208, 210, 212, 214, 216, and 218. In a given implementation, controller 220 includes a processor 222 and a memory 224. The processor 222 may represent multiple processors, and the memory 224 may represent multiple memories. In an embodiment, the controller 220 may include a number of software components that are stored in a computer-readable medium, such as memory 224, and are executable by processor 222. In this respect, the term “executable” includes a program file that is in a form that can be directly (e.g. machine code) or indirectly (e.g. source code that is to be compiled) performed by the processor 222. An executable program may be stored in any portion or component of memory 224.
Recovery mode manager 100 may also be implemented in an environment such as environment 300 of
In the foregoing discussion, various components were described as combinations of hardware and programming. Such components may be implemented in a number of fashions. In one example, the programming may be processor executable instructions stored on tangible memory media and the hardware may include a processor for executing those instructions. Thus, certain elements operating on the same device may share a common processor and common memory media.
OPERATION:
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Each of the first row 602 and second row 604 includes printheads 606 of the color types black (“K”), cyan (“C”), yellow (“Y”), and magenta (“M”). In an embodiment, the yellow (“Y”) type printheads 620 are positioned on the carriage 608 such that the nozzle array 616 of the yellow (“Y”) printhead 620 of the first row 602 overlap 622 with nozzle array 616 of the yellow (“Y”) printhead of the second row 604. This enables same color printing with a swath length approximately equal to the combined length 624 of the nozzle arrays 616.
A first printing 626 (
In an example, it may be detected that a second printhead 632, a cyan (“C”) type printhead, in the second row 604 is failed, and that a third printhead 634 in the first row 602 of the same cyan (“C”) color type is a healthy, i.e., operable printhead. An exchange of the second printhead 632 and the third printhead 634 is caused. This exchange enables recovery mode printing to take place by rending all of the printheads in the second row operable to complete the print job.
The disclosed print recovery mode is explained describing a first printhead row and a second printhead row. This is not intended to restrict the disclosure to a recovery print mode utilizing two printhead rows. This disclosure is equally applicable to print recovery mode utilizing any number of rows of printheads great than one.
In an embodiment, a first printing is caused in response to a print job, applying ink upon the media 712 utilizing the first row 702 of printheads and the second 704, third 706, fourth 708 and fifth 710 rows of printheads adjacent to the first row 702. The second through fifth rows include at least one printhead of each of the types contained in the first row 702. Upon detection of a failure of a first printhead within the first row 702, the status of the printheads included within the second through fifth rows is analyzed. In response to determining that the printheads within the second, third, fourth and fifth rows are operable to complete the print job, a second printing 630 is caused to continue the print job utilizing the second 704, third 706, fourth 708 and fifth 710 rows, and not the first row 702, of printheads.
CONCLUSION: The diagrams of
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Also, the present disclosure may be embodied in any computer-readable media for use by or in connection with an instruction execution system such as a computer/processor based system or an ASIC (Application Specific Integrated Circuit) or other system that can fetch or obtain the logic from computer-readable media and execute the instructions contained therein. “Computer-readable media” can be any media that can contain, store, or maintain programs and data for use by or in connection with the instruction execution system. Computer readable media can comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, or semiconductor media. More specific examples of suitable computer-readable media include, but are not limited to, a portable magnetic computer diskette such as floppy diskettes or hard drives, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory, or a portable compact disc.
The preceding description has been presented only to illustrate and describe embodiments and examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the above teaching.