1. Technical Field
The present invention relates to a fluid ejecting apparatus that is provided with a fluid ejecting head that ejects fluid onto a fluid ejection target medium. In addition, the invention further relates to a fluid ejection control method that is used by such a fluid ejecting apparatus. A non-limiting specific example of the fluid ejecting apparatus is an ink-jet printer, which ejects ink onto a sheet of recording paper from its recording head.
2. Related Art
As an example of various kinds of fluid ejecting apparatuses, an ink-jet printer that discharges ink drops onto a sheet of printing paper from the ink-jet recording head thereof is known in the art. Such a known ink-jet printer is disclosed in, for example, JP-A-2007-69448, JP-A-2005-67127, and JP-A-2005-280192. Herein, a sheet of printing paper is an example of the fluid ejection target medium, or, in other words, recording target medium. Each of the ink-jet printers disclosed in JP-A-2007-69448, JP-A-2005-67127, and JP-A-2005-280192 is a line-type ink-jet recording apparatus, which is hereafter referred to as a line printer or a line-head printer. There is more than one type in line printers. Some line printers have a plurality of recording heads that are arrayed along the direction of the width of a sheet of recording paper that is perpendicular to the transport direction thereof. Examples of such a configuration are disclosed in the above-identified unexamined Japanese patent application publications of JP-A-2007-69448 (specifically, refer to FIGS. 1 and 4 thereof) and JP-A-2005-67127 (specifically, refer to FIG. 1 thereof). Other line printers have an elongated recording head that extends to cover the entire width of a sheet of recording paper. An example of such a configuration is disclosed in the above-identified unexamined Japanese patent application publication of JP-A-2005-280192 (specifically, refer to Paragraph [0014] of Specification as well as FIGS. 2 and 3 thereof).
In a typical configuration of a line-head printer of the related art, a recording head(s) is provided as an immovable part/component. For this reason, although it is possible to use all nozzles for printing at the time when the printing is performed on a sheet of printing paper having a size equal to the maximum printable size, it is not possible to use all nozzles for printing at the time when the printing is performed on a sheet of printing paper having a size smaller than the maximum one. Specifically, no ink is ejected from nozzles that are arrayed at positions outside the maximum printable area (i.e., maximum printable range), which is dependent on (i.e., determined by) the width of the sheet of printing paper if it has a narrower width than the maximum printable width. This could cause the thickening of ink in such outer nozzles. The thickened ink could further cause the clogging of these nozzles. In order to provide a solution to such a problem, printers perform so-called flushing operation at predetermined time intervals during the execution of printing. For example, a printer performs the flushing operation at ten-second intervals. In the flushing operation, a printer ejects ink drops in a forcible manner, that is, not for the purpose of printing or independently thereof. By this means, the printer discharges any thickened ink out of the nozzles for renewing the state thereof. The flushing makes it possible to prevent the clogging, or other related problems, of some nozzles that are rarely used (or not used at all) for printing or some nozzles that are used for printing less frequently than others.
Despite the fact that the flushing provides an effective solution to the clogging of nozzles to some extent, the thickness of ink retained in a recording head never remains at a constant level. The same holds true for the thickness of ink remaining in nozzles. For example, during a time period of the traveling of ink inside a resin-made ink tube through which ink is supplied from an ink cartridge to a recording head, the moisture (i.e., a solvent or a dispersion medium) of the ink evaporates through the resin into air. As a result of the evaporation of the moisture thereof, the thickness of ink increases. Therefore, depending on the length of the retention time of ink inside the ink tube, or, in other words, depending on how long ink remains inside the ink tube, the thickness level of ink retained in a recording head could differ from one to another. In like manner, the thickness level of ink remaining in nozzles could vary from one to another depending on air temperature, air humidity, or other factors. Therefore, the actual thickness level of ink inside nozzles could be very high depending on the above-described conditions. In such a case, ink-discharge performance will be poor even if the flushing operation is performed at regular intervals. It is conceivable to shorten the cycle of flushing operation in order to overcome such a problem. However, if such a solution approach is employed/used, it will inevitably increase the consumption amount of ink that is wasted without being used for printing. In order to offer high printing cost performance, there is a limit in shortening the cycle of flushing operation.
An advantage of some aspects of the invention is to provide a fluid ejecting apparatus that can provide enhanced fluid ejection opportunity to a greater number of nozzles of a fluid ejecting head so as to prevent, or at least reduce, the clogging of the nozzles or other-related malfunctions. In addition, the invention further provides, as an advantage of some aspects thereof, a fluid ejection control method that is used by such a fluid ejecting apparatus.
In order to address the above-identified problem without any limitation thereto, the invention provides, as a first aspect thereof, a fluid ejecting apparatus that includes: an apparatus body; and a plurality of fluid ejecting heads that can eject fluid onto a fluid ejection target medium; wherein at least one of the plurality of fluid ejecting heads can move in a predetermined direction that intersects the transport direction of the fluid ejection target medium so as to change the relative positions of the plurality of fluid ejecting heads as viewed in the predetermined direction that intersects the transport direction of the fluid ejection target medium.
In the configuration of a fluid ejecting apparatus according to the first aspect of the invention described above, at least one of the plurality of fluid ejecting heads is moved in a predetermined direction that intersects the transport direction of the fluid ejection target medium so as to change the relative positions of the plurality of fluid ejecting heads as viewed in the predetermined direction that intersects the transport direction of the fluid ejection target medium. By this means, it is possible to set, for example, all nozzles at positions corresponding to the maximum fluid ejectable range that is in accordance with the size of the fluid ejection target medium. Therefore, it is possible to increase the number of nozzles that are actually used for ejecting fluid onto the fluid ejection target medium in fluid ejection processing (e.g., print processing). Accordingly, it is further possible to decrease the adverse possibility of the clogging of nozzles, the shortage of ink ejection amount, and/or other related problems that are caused as a result of poor fluid exchange inside the nozzles due to scarce ink ejection opportunity.
It is preferable that the fluid ejecting apparatus according to the first aspect of the invention described above should further include: a movable guiding section that can move so as to determine the position of the fluid ejection target medium as viewed in the predetermined direction that intersects the transport direction of the fluid ejection target medium; wherein the above-mentioned at least one of the plurality of fluid ejecting heads that can move in the predetermined direction that intersects the transport direction of the fluid ejection target medium moves together with the movable guiding section.
With such a preferred configuration of the fluid ejecting apparatus according to the first aspect of the invention, the above-mentioned at least one of the plurality of fluid ejecting heads moves together with the movable guiding section in the predetermined direction that intersects the transport direction of the fluid ejection target medium upon the movement, by a user, of the movable guiding section so as to determine the position of the fluid ejection target medium as viewed in the predetermined direction that intersects the transport direction of the fluid ejection target medium. By this means, it is possible to move the above-mentioned at least one movable fluid ejecting head to a position that is in accordance with the size of the fluid ejection target medium. For example, it is possible to set all nozzles at positions where the fluid ejection heads can eject fluid in the maximum fluid ejectable range that is in accordance with the size of the fluid ejection target medium.
In the preferred configuration of the fluid ejecting apparatus according to the first aspect of the invention described above, it is further preferable that one edge of the fluid ejection target medium as viewed in the direction of the width of the fluid ejection target medium should be taken as a guide basis; and the movable guiding section should be able to move in such a manner that the movable guiding section guides the other opposite edge of the fluid ejection target medium as viewed in the width direction of the fluid ejection target medium.
With such a preferred configuration of the fluid ejecting apparatus according to the first aspect of the invention, it is possible to fix the base-side (one edge of the fluid ejection target medium as viewed in the direction of the width of the fluid ejection target medium) one of the plurality of fluid ejecting heads. Therefore, it is possible to decrease the number of fluid ejecting heads that is necessary to move together with a target-position-determining section that includes but not limited to the movable guiding section. Therefore, it is possible to achieve a simple configuration with a smaller number of movable components.
It is preferable that the fluid ejecting apparatus according to the first aspect of the invention described above should further include: a plurality of caps that are used for capping the plurality of fluid ejecting heads, respectively, wherein the cap that corresponds to, or the caps that correspond to, the above-mentioned at least one of the plurality of fluid ejecting heads that can move in the predetermined direction that intersects the transport direction of the fluid ejection target medium can move together with the above-mentioned at least one of the plurality of fluid ejecting heads.
In the preferred configuration of the fluid ejecting apparatus according to the first aspect of the invention described above, the cap that corresponds to, or the caps that correspond to, the above-mentioned at least one of the plurality of fluid ejecting heads that can move in the predetermined direction that intersects the transport direction of the fluid ejection target medium move(s) together with the above-mentioned at least one of the plurality of fluid ejecting heads. Therefore, it is possible for each of the above-mentioned at least one of the plurality of fluid ejecting heads to immediately discharge fluid into the corresponding cap at its movement destination position without any further extra movement therefrom. Therefore, it is possible to avoid any ineffective extra movement of the fluid ejecting head so as to allow the fluid ejecting head to discharge fluid into the corresponding cap.
It is preferable that the fluid ejecting apparatus according to the first aspect of the invention described above should further include: a detecting section that can detect the position of the above-mentioned at least one movable fluid ejecting head as viewed in the predetermined direction that intersects the transport direction of the fluid ejection target medium; and a controlling section that identifies an overlapping area at which the plurality of fluid ejecting heads overlap each other or one another as viewed in the transport direction of the fluid ejection target medium in a fluid ejectable range on the basis of the detection result of the detecting section and then controls the plurality of fluid ejecting heads in such a manner that overlapping two or more fluid ejecting heads eject fluid in the identified overlapping area while shifting fluid landing positions on the fluid ejection target medium therebetween or thereamong. In the preceding sentence, the meaning of the phrase “shifting fluid landing positions on the fluid ejection target medium therebetween or thereamong” includes both of the following: firstly, fluid landing positions are shifted on a single fluid ejection target medium; secondly, fluid ejection target media onto which fluid lands are switched over.
In the preferred configuration of the fluid ejecting apparatus according to the first aspect of the invention described above, a detecting section detects the position of the above-mentioned at least one movable fluid ejecting head as viewed in the predetermined direction that intersects the transport direction of the fluid ejection target medium. In addition, a controlling section identifies an overlapping area at which the plurality of fluid ejecting heads overlap each other or one another as viewed in the transport direction of the fluid ejection target medium in a fluid ejectable range on the basis of the detection result of the detecting section. Then, the controlling section controls the plurality of fluid ejecting heads in such a manner that overlapping two or more fluid ejecting heads eject fluid in the identified overlapping area while shifting fluid landing positions on the fluid ejection target medium therebetween or thereamong. Therefore, the number of nozzles that are not actually used for fluid ejection decreases in the overlapping area at which the plurality of fluid ejecting heads overlap each other or one another as viewed in the transport direction of the fluid ejection target medium. By this means, it is possible to effectively prevent or reduce the clogging of nozzles or any other related problems.
In the preferred configuration of the fluid ejecting apparatus according to the first aspect of the invention described above, it is further preferable that the controlling section should switch over fluid ejecting heads for ejection of fluid at the identified overlapping area at each time when the fluid ejection target media are changed over.
If the preferred configuration described above is adopted, the controlling section switches over fluid ejecting heads for ejection of fluid at the identified overlapping area at each time when the fluid ejection target media are changed over. Since fluid ejecting heads are switched over on a target-by-target basis, it is possible to simplify fluid ejection control.
It is further preferable that the fluid ejecting apparatus having the preferred configuration described above should further include a driving section that moves the above-mentioned at least one movable fluid ejecting head in the predetermined direction that intersects the transport direction of the fluid ejection target medium, wherein the detecting section can detect the movement position of the movable guiding section; and the controlling section controls the driving operation of the driving section on the basis of the detection result of the detecting section so as to move the above-mentioned at least one movable fluid ejecting head to a position that is in accordance with the width of the fluid ejection target medium.
In the preferred configuration of the fluid ejecting apparatus described above, the detecting section detects the movement position of the movable guiding section that is manipulated (e.g., slid) by a user in accordance with the size (i.e., width) of the fluid ejection target medium. Then, the controlling section controls the driving operation of the driving section on the basis of the detection result of the detecting section so as to move the above-mentioned at least one movable fluid ejecting head to a position that is in accordance with the movement position of the movable guiding section. As described above, the above-mentioned at least one movable fluid ejecting head moves as driven by the driving section. Accordingly, the preferred configuration described above has an advantage in that a user can slide the movable guiding section with a smaller force and thus easily. In addition, the preferred configuration described above has another advantage in that, even when the user inadvertently touches the movable guiding section during the execution of fluid ejection, it is possible to avoid the fluid-ejection position of the fluid ejecting head from being displaced as a result of the unintended movement of the fluid ejecting head together with the inadvertent movement of the movable guiding section.
In order to address the above-identified problem without any limitation thereto, the invention provides, as a second aspect thereof, a fluid ejection control method that is used by a fluid ejecting apparatus, the fluid ejecting apparatus having a plurality of fluid ejecting heads that can eject fluid onto a fluid ejection target medium, at least one of the plurality of fluid ejecting heads being able to move in a predetermined direction that intersects the transport direction of the fluid ejection target medium so as to change the relative positions of the plurality of fluid ejecting heads as viewed in the predetermined direction that intersects the transport direction of the fluid ejection target medium, the fluid ejection control method including: moving the above-mentioned at least one movable fluid ejecting head to a position so as to position all nozzles inside the maximum fluid ejectable range that is determined by the size of the fluid ejection target medium; and controlling, if there is an overlapping area at which the fluid ejectable ranges of the plurality of fluid ejecting heads overlap each other or one another as viewed in the transport direction of the fluid ejection target medium, the plurality of fluid ejecting heads in such a manner that overlapping two or more fluid ejecting heads eject fluid in the overlapping area while shifting fluid landing positions on the fluid ejection target medium therebetween or thereamong.
The fluid ejection control method according to the second aspect of the invention described above offers the same advantageous effects as those offered by the fluid ejecting apparatus according to the first aspect of the invention described above.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
With reference to
An ink-jet recording apparatus according to the present embodiment of the invention, which is hereafter referred to as a printer 11, is configured as a line printer that is provided with a plurality of line heads. Specifically, as shown in
Each of the pair of line heads 12 and 13 hangs from the slide rail 15. These line heads 12 and 13 are arrayed not in alignment with each other. Specifically, the hanging positions of these two line heads 12 and 13 are shifted from each other so as to form an upstream line and a downstream line as viewed in the direction of paper transport, which is the X direction in
The aforementioned four driving shafts 14 shown in
As illustrated in
As illustrated in
As illustrated in
The cap 21 is provided on a first line in such a manner that cap 21 is exposed through the opening 18A of the platen 18 as illustrated in
In the configuration of the printer 11 according to the present embodiment of the invention, the first-line line head 12, which is a movable part/component, and the first-line maintenance apparatus 23 are coupled to each other by means of a coupling member 30. The coupling member 30 is connected to one end of the movable first-line line head 12 and also to the corresponding one end of the maintenance apparatus 23. With such a structure, the line head 12 and the maintenance apparatus 23 can move together in the paper-width Y direction. Therefore, the caps 21 and 22 are always positioned under the line heads 12 and 13 in such a manner that the caps 21 and 22 always face the line heads 12 and 13, respectively. The elevation mechanism 26 is a kind of power transmission mechanism that transforms/converts the rotation force of the electric motor 27 to the elevation force of the cap 21 (22), that is, power for moving up/down the cap 21 (22). As an example of inner components thereof, the elevation mechanism 26 is provided with a cam mechanism such as a rotating cam or a cylindrical cam (i.e., drum cam), though not limited thereto. Needless to say, it is possible to adopt an alternative power source other than one described above, including but not limited to, a cylinder, a solenoid, or a piezoelectric actuator.
As illustrated in
As illustrated in
As illustrated in
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As illustrated in
Since the coupling rod 45 extends in the paper-transport X direction from the movable guide portion 36A of the movable guide member 36, the coupling rod 45 is always positioned outside a sheet of printing paper 20 regardless of the sheet size thereof. Or, in other words, the coupling rod 45 is always positioned outside the above-mentioned outer end (i.e., one end) of the elongated line head 12 that is opposite to the above-mentioned other end thereof, where the above-mentioned other end of the elongated line head 12 is closer to the fixed guide portion 35A of the guide support member 35 than the above-mentioned one end thereof as viewed along the paper-width Y direction. For this reason, the coupling rod 45 never obstructs the transport of the sheet of printing paper 20. In addition, as illustrated in
The upper part of the line head 12 is formed as a guide portion 12D that is formed so as to fit with the rail portion 15A of the slide rail 15. Since the guide portion 12D of the line head 12 is in engagement with the rail portion 15A of the slide rail 15, the line head 12 hangs from the slide rail 15 in such a manner that the line head 12 is allowed to move in the paper-width Y direction in a sliding manner thereunder. Having the above-described structure, the line head 12 can move in the paper-width Y direction together with the maintenance apparatus 23. In addition, because of the above-described structure, the line head 12 can move in the vertical Z direction with respect to (i.e., as viewed from) the platen 18 and the maintenance apparatus 23.
As illustrated in
At the time when printing is performed on a sheet of printing paper 20 having the maximum sheet size (e.g., A3 paper size), as a result of the sliding operation of the movable guide portion 36A of the movable guide member 36 in the paper-width Y direction, the paper-width Y position of the line head 12 is shifted from the paper-width Y position of the line head 13 so that they scarcely overlap each other when viewed along the paper-transport X direction. A non-limiting example of such shifted and thus non-overlapping relative positions of the line heads 12 and 13 is illustrated in
A built-in ejection drive element is provided for each nozzle of the line head 12 (13). These ejection drive elements are not shown in the drawing. As these ejection drive elements are driven, a force to eject ink is applied thereto. As a result thereof, the line head 12 (13) discharges ink drops from the nozzles thereof. As a few examples of a variety of eject-drive methods, a piezoelectric scheme, an electrostatic actuation scheme, or a thermal ejection scheme may be adopted, though not limited thereto. In the piezoelectric scheme, piezoelectric vibration elements are used as ejection drive elements. In the electrostatic actuation scheme, electrostatic actuators are used as ejection drive elements. In the thermal ejection scheme, a heater is used as ejection drive elements. An example of the thermal ejection scheme is a film-boiling method.
As the movable guide portion 36A of the movable guide member 36 that constitutes a part of the paper guide 34 moves in a sliding manner in the paper-width Y direction, the relative positions of the line heads 12 and 13 change. For example, as illustrated in
As illustrated in
In the configuration of the printer 11 according to the present embodiment of the invention, the maximum printable area, which is a non-limiting example of the “maximum fluid ejectable range” according to the invention, is determined with the addition of a predetermined outside run-over length at each of the left and right edges of a sheet of printing paper 20 having the maximum sheet size viewed along the paper-width Y direction. Because of the addition of the predetermined outside run-over length at each of the left and right edges thereof, the printer 11 according to the present embodiment of the invention can perform so-called borderless printing on a sheet of printing paper 20 having the maximum sheet size without leaving no paper margin thereon under the positional setting of the first-line line head 12 and the second-line line head 13 shown in
The controller 50 has, as its inner components, a CPU 61, an ASIC (Application Specific IC) 62, a ROM 63, a RAM 64, and a flash memory 65. The ROM 63 stores various kinds of programs that can be executed by the CPU 61. The RAM 64 is used as a work memory into which the CPU 61 can temporarily store data such as the result of calculation, though not necessarily limited thereto. The flash memory 65 stores, though not necessarily limited thereto, reference data that is used for determining the specific control behavior of ink-discharging operation that is performed by each of the line heads 12 and 13. In the configuration of the printer 11 according to the present embodiment of the invention, the flash memory 65 stores table data as the reference data. The table data stored in the flash memory 65 shows a relationship between the detected position of the line head 12 and the nozzle-overlap area at which, or, in other words, overlapping amount by which, the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13 overlap each other. With such a configuration, the CPU 61 refers to the table data so as to identify nozzles that are located inside the nozzle-overlap area (i.e., overlapping-nozzle area) at which the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13 overlap each other on the basis of the position of the line head 12 detected by the position sensor 58. For example, the CPU 61 can identify the nozzle numbers of nozzles that are located inside the nozzle-overlap area at which the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13 overlap each other.
A predetermined flushing execution time interval is set in advance. The flushing execution time interval is preset at, for example, 5-20 seconds. At each time when the flushing execution time elapses, which is measured by means of a timer that is not shown in the drawing, flushing operation is executed. Or, more specifically, after the elapsing of the flushing execution time, flushing operation is executed during a time period in which no sheet of printing paper 20 is present over the caps 21 and 22 after the ejection of the current sheet of printing paper 20 therefrom and before the incoming transport of the next sheet of printing paper 20 thereto. For example, flushing is performed at each time when the predetermined number of sheets of printing paper has been printed if the printing speed is high, whereas flushing is performed at each time when one sheet of printing paper has been printed if a high print resolution is required.
Prior to the start of printing, a user sets sheets of printing paper 20 on the paper guide 34 and then moves the movable guide portion 36A of the movable guide member 36 in accordance with the width size of the sheets of printing paper 20. As a result of the movement of the movable guide portion 36A of the movable guide member 36, the position of the line head 12, which moves together with the movable guide portion 36A of the movable guide member 36, is determined in accordance with the width size of the sheets of printing paper 20. For example, if the sheets of printing paper 20 have the maximum size, the relative positions (i.e., positional relationship) of the first-line line head 12 and the second-line line head 13 are set as illustrated in
After having determined the set position of the line head 12, the user sets/specifies printing conditions by manipulating the input device of a host computer that is not illustrated in the drawing. Examples of the printing parameters that are set/specified by the user include but not limited to, a paper type, a paper size, a layout, color/monochrome, and quality (high-quality printing/draft printing). At the host computer, a printer driver performs resolution conversion processing so as to convert the resolution of image data into print resolution. Next, for example, RGB image data is converted into CMYK image data in accordance with printing conditions. Then, the host computer sends the processed data to the printer 11 as bitmap print data. Upon reception of the print data, the printer 11 starts printing.
Upon the start of printing, in the first step S10 of the ink-discharging control processing routine, the CPU 61 detects the position of the movable guide portion 36A of the movable guide member 36 as viewed along the paper-width Y direction on the basis of a position signal that is supplied from the position sensor 58. Or, in other words, in the first step S10 of the ink-discharging control processing routine, the CPU 61 detects the positions of the line head 12, which lies on the first line, and the maintenance apparatus 23 as viewed along the paper-width Y direction on the basis of the position signal that is supplied from the position sensor 58.
In the next step S20, the CPU 61 refers to table data that has been read out of the flash memory 65 so as to make a judgment as to whether there is any overlap between the nozzle lines 12B of the first-line line head 12 and the nozzle lines 13B of the second-line line head 13 on the basis of the position detected by the position sensor 58. That is, in this step S20, the CPU 61 makes a judgment as to whether the nozzle lines 12B of the first-line line head 12 overlap, at least partially, the nozzle lines 13B of the second-line line head 13 or not on the basis of the position detected by the position sensor 58 as viewed along the paper-transport X direction.
For example, at the time when a sheet of printing paper 20 having the maximum sheet size (e.g., A3 paper size) is printed, the movable guide portion 36A of the movable guide member 36 is set at the outermost position as illustrated in
In the step S30, all nozzles are set as active nozzles that are actually used for printing because it was judged in the preceding step S20 that there is not any overlap between the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13. Thereafter, printing is executed in the next step S40. In the print execution step of S40, there are greater opportunities/possibilities for the ejection of ink from all nozzles at least once during the execution of printing because all nozzles are set as active nozzles that are actually used for printing. After the printing of one sheet of printing paper 20 has completed, the CPU 61 makes a judgment as to whether the commanded printing job has ended or not (step S50). If the printing job has not ended yet (step S50: NO) because there is/are any sheet(s) of printing paper 20 waiting to be printed, the printer 11 ejects the current (i.e., printing-completed) sheet of printing paper 20 and feeds the next sheet of printing paper 20 for successive printing. The judgment step S50 is repeated at each time of the completion of the printing of one sheet of printing paper 20 until the CPU 61 judges that the printing job has ended (step S50: YES). If the positive judgment result is outputted in this judgment step S50, which means that the commanded printing job has been ended for all sheets of printing paper 20, the CPU 61 terminates the ink-discharging control processing routine described herein.
On the other hand, if the CPU 61 judged in the aforementioned step S20 that the nozzle lines 12B of the first-line line head 12 overlap, at least partially, the nozzle lines 13B of the second-line line head 13 as viewed along the paper-transport X direction on the basis of the positions of the first-line line head 12 and the maintenance apparatus 23, the CPU 61 identifies, in the step S60, the nozzle-overlap area at which the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13 overlap each other by means of the result of positional detection made by the position sensor 58. In a case where the line head 12 is positioned relative to the line head 13 in such a manner that the nozzle lines 12B of the line head 12 at least partially overlap the nozzle lines 13B of the line head 13 as illustrated in
In the step S70, the CPU 61 prioritizes the first-line line head 12 over the second-line line head 13 at the nozzle-overlap area at which the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13 overlap each other and thus sets the nozzles of the first-line line head 12 as active nozzles that are actually used for printing at the above-described nozzle-overlap area (i.e., overlapping-nozzle area). For example, in the nozzle-number example described above, the nozzles #101-#180 of the first-line line head 12 are set as active nozzles that are actually used for printing at the above-described nozzle-overlap area. At the non-overlap area at which the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13 do not overlap each other, the remaining nozzles that are located outside the above-described nozzle-overlap area are set as active nozzles that are actually used for printing. That is, the nozzles #1-#100 of the first-line line head 12 and the nozzles #81-#180 of the second-line line head 13 are set as active nozzles that are actually used for printing at the above-described non-overlap area. Then, in the step S80, printing is executed by means of nozzles having nozzle numbers that are set as the number of active nozzles that are actually used for printing.
In the step S90, the CPU 61 makes a judgment as to whether nozzle-switchover conditions have been satisfied or not. In the configuration of the printer 11 according to the present embodiment of the invention, the nozzle-switchover conditions are set as the changing of print-target sheets of paper 20 due to the ejection of the current sheet of print-completed paper 20 and the feeding of the next sheet of printing paper 20. Therefore, it is judged in the step S90 that the nozzle-switchover conditions are satisfied at the time when print-target sheets of paper 20 are changed due to the ejection of the current sheet of print-completed paper 20 and the feeding of the next sheet of printing paper 20. Then, the process moves on to the next step S100.
In the step S100, the CPU 61 switches over the active nozzles that are actually used for printing at the nozzle-overlap area at which the nozzle lines 12B of the first-line head 12 and the nozzle lines 13B of the second-line head 13 overlap each other from the nozzles of the first-line line head 12 to the nozzles of the second-line line head 13. In the foregoing example, the active nozzles that are actually used for printing at the nozzle-overlap area at which the nozzle lines 12B of the first-line head 12 and the nozzle lines 13B of the second-line head 13 overlap each other are switched over from the nozzles #101-#180 of the first-line line head 12 to the nozzles #1-#80 of the second-line line head 13. Then, a series of steps from S80 inclusive to S110 inclusive is repeated until printing is completed for all print-instructed sheets of printing paper. At each time when print-target sheets of paper 20 are changed due to the ejection of the current sheet of print-completed paper 20 and the feeding of the next sheet of printing paper 20, the active nozzles that are actually used for printing at the nozzle-overlap area at which the nozzle lines 12B of the first-line head 12 and the nozzle lines 13B of the second-line head 13 overlap each other are switched over, in alternate shifts, between the nozzles #101-#180 of the first-line line head 12 and the nozzles #1-#80 of the second-line line head 13.
In the illustrated example of
By this means, in a case where the nozzle lines 12B of the first-line line head 12 partially overlap the nozzle lines 13B of the second-line line head 13 when viewed along the paper-transport X direction, thereby forming a partial nozzle-overlap area as illustrated in
Control for switching over the active nozzles that are actually used for printing at the nozzle-overlap area at which the nozzle lines 12B of the first-line head 12 and the nozzle lines 13B of the second-line head 13 overlap each other is performed as follows. As a first step of active-nozzle switchover control, print data (bitmap data) is expanded on a memory such as the RAM 64, though not necessarily limited thereto. Then, the expanded data is read out in the readout unit of one raster line for the nozzle lines 12B, 13B at a time, or, in other words, the expanded data is read out for one raster line of the nozzle lines 12B, 13B at each single readout execution. While the expanded data is read out in such a way, a data portion that should be printed out by the nozzles of the first-line line head 12 is transferred to the first-line driver system of the head driver 51 that is dedicated for driving the first-line line head 12 whereas a data portion that should be printed out by the nozzles of the second-line line head 13 is transferred to the second-line driver system of the head driver 51 that is dedicated for driving the second-line line head 13. In the above-explained distribution (i.e., transfer) of the data portions of readout data, the data-transfer destination of a data portion that should be printed out by nozzles located in the nozzle-overlap area is determined on the basis of the initial conditions of the above-explained step S70 illustrated in
The aforementioned flushing is carried out at each point in time at which no sheet of printing paper 20 is present between the first-line line head 12 and the cap 21 as well as between the second-line line head 13 and the cap 22 because of the ejection of a print-completed sheet of printing paper 20 after the elapsing of the aforementioned flushing execution time (i.e., preset flushing execution interval/flushing set time) during the execution of printing. In the flushing, all nozzles of the first-line line head 12 and the second-line line head 13 discharge ink drops toward the caps 21 and 22, respectively.
In the configuration of the printer 11 according to the present embodiment of the invention, the movable first-line line head 12 moves together with the movement of the movable guide portion 36A of the movable guide member 36. Because of such a structure, all nozzles of the movable first-line line head 12 are positioned inside the maximum printable area that is determined on the basis of the size of a sheet of printing paper 20. Therefore, all nozzles are used as the aforementioned active nozzles at the time when, for example, borderless printing is performed. In comparison with the configuration of a fixed/immovable line head of the related art, the movable line-head configuration of the printer 11 according to the present embodiment of the invention makes it possible to increase the ink-ejection opportunities for all nozzles during printing. Although a small number of nozzles that are provided in the predetermined outside run-over area are not used as the aforementioned active nozzles in borderless printing, almost all of nozzles except for the outside run-over nozzles are always used as the active nozzles regardless of the sheet size of printing paper. As understood from the foregoing explanation of the movable line-head configuration of the printer 11 according to the present embodiment of the invention, it is possible to make the number of nozzles from which ink drops are ejected for printing larger in comparison with that of a fixed/immovable line head of the related art. As the number of nozzles from which ink drops are ejected for printing increases, the number of nozzles from which ink drops are ejected only for flushing decreases. As a result thereof, the movable line-head configuration of the printer 11 according to the present embodiment of the invention makes it possible to effectively prevent or reduce the clogging of nozzles.
As explained in detail above, the printer 11 according to the present embodiment of the invention offers the following advantageous effects of the invention.
(1) Since the relative positions of the movable first-line line head 12 and the second-line line head 13 as viewed along the paper-width Y direction can be changed, it is possible to position all nozzles inside the maximum printable area that is determined on the basis of the size of a sheet of printing paper 20. By this means, it is possible to give ink-ejection opportunity to a larger number of nozzles. As a result thereof, it is possible to effectively prevent the thickening of ink inside nozzles and thus further prevent the clogging of the nozzles. For example, as has already been explained above, during a time period of the traveling of ink inside a resin-made ink tube through which ink is supplied from an ink cartridge to a recording head, the moisture of the ink evaporates through the resin into air. As a result of the evaporation of the moisture thereof, the thickness of ink increases. Therefore, depending on the length of the retention time of ink inside the ink tube, or, in other words, depending on how long ink remains inside the ink tube, the thickness level of ink retained in a recording head could be high. In like manner, the thickness level of ink remaining in nozzles could be high depending on the temperature and/or humidity of a print-execution environment or other factors. Even if the thickness level of ink remaining in nozzles is considerably high for the above-described reason, though not limited thereto, the movable line-head configuration of the printer 11 according to the present embodiment of the invention makes it possible to significantly reduce the adverse possibility of the clogging of nozzles just by performing flushing that is executed at each elapsing of normal flushing execution time.
(2) The first-line line head 12 moves together with the movable guide portion 36A of the movable guide member 36, which constitutes a part of the paper guide 34, as the movable guide portion 36A of the movable guide member 36 is moved in a sliding manner. Therefore, the printer 11 according to the present embodiment of the invention makes it possible to set the first-line line head 12 at a right position that is in accordance with the size of the sheet of printing paper 20 without requiring any dedicated or special power source and/or control thereof for moving the first-line line head 12.
(3) The paper guide 34 offers the aforementioned one-side slide paper adjustment. Therefore, it is possible to achieve the advantageous configuration of the printer 11 according to the present embodiment of the invention with a single movable line head, which is the first-line line head 12 in the exemplary embodiment of the invention, and an immovable/fixed line head, which is the second-line line head 13 in the exemplary embodiment of the invention. For example, if a center paper adjustment structure is adopted, it is necessary to configure both of the first-line line head 12 and the second-line line head 13 as movable line heads. The configuration of the printer 11 according to the present embodiment of the invention is advantageous over such a center-paper-adjustment configuration in that it is possible to reduce the number of movable components, which generally have a more complex structure than that of immovable components. Therefore, the printer 11 according to the present embodiment of the invention features a relatively simple structure.
(4) In addition to the first-line line head 12, the maintenance apparatus 23 also moves together with the movable guide portion 36A of the movable guide member 36, which constitutes a part of the paper guide 34, as the movable guide portion 36A of the movable guide member 36 is moved in a sliding manner. Therefore, the printer 11 according to the present embodiment of the invention makes it possible to perform flushing/cleaning easily no matter where the first-line line head 12 is positioned. If the maintenance apparatus 23 does not move together with the movable guide portion 36A of the movable guide member 36, the first-line line head 12 only moves, that is, not together with the cap 21 of the maintenance apparatus 23. In such a case, it is necessary to move the first-line line head 12 from a printing position to a maintenance position so as to perform flushing and/or cleaning. Since the movement of the maintenance apparatus 23 is also associated with the sliding movement of the movable guide portion 36A of the movable guide member 36, it is possible to eliminate need for any dedicated or special power source and/or control thereof for moving the maintenance apparatus 23. Therefore, the printer 11 according to the present embodiment of the invention features a relatively simple structure.
(5) The printer 11 according to the present embodiment of the invention is provided with the position sensor 58. The CPU 61 recognizes the nozzle-overlap area at which the nozzle lines 12B of the first-line head 12 and the nozzle lines 13B of the second-line head 13 overlap each other on the basis of a detection signal supplied from the position sensor 58. If the CPU 61 judges that there is such a nozzle-overlap area, ink-landing positions on a sheet of printing paper 20 are switched over between the first-line line head 12 and the second-line line head 13. Through the above-described nozzle switchover, both of the nozzles of the first-line line head 12 and the nozzles of the second-line line head 13 are used as the aforementioned active nozzles that are actually used for printing. As a result thereof, it is possible to effectively prevent the thickening of ink inside nozzles and thus further prevent the clogging of the nozzles.
(6) In the configuration of the printer 11 according to the present embodiment of the invention, active nozzles that are actually used for printing at the nozzle-overlap area at which the nozzle lines 12B of the first-line head 12 and the nozzle lines 13B of the second-line head 13 overlap each other are switched over between the nozzles of the first-line line head 12 and the nozzles of the second-line line head 13 at each time when print-target sheets of paper 20 are changed over due to the ejection of the current sheet of print-completed paper 20 and the feeding of the next sheet of printing paper 20. Because of such a configuration, all nozzles of the first-line line head 12 and the second-line line head 13 could be designated as ink-ejection nozzles with an increased ink-ejection opportunity. By this means, it is possible to effectively prevent the clogging of nozzles and other related problems. In addition, it is possible to simplify the control behavior of ink-discharging operation that is performed by each of the first-line line head 12 and the second-line line head 13 because the active nozzles are switched over at each time when print-target sheets of paper 20 are changed over.
Although a fluid ejecting apparatus having distinctively unique features of the present invention is described above while explaining preferred exemplary embodiments thereof, the invention should be in no case interpreted to be limited to the specific embodiments described above. The invention may be modified, altered, changed, adapted, and/or improved within a range not departing from the gist and/or spirit of the invention apprehended by a person skilled in the art from explicit and implicit description made herein, where such a modification, an alteration, a change, an adaptation, and/or an improvement is also covered by the scope of the appended claims. The followings are non-limiting examples of a modification, an alteration, a change, an adaptation, and/or an improvement of the preferred exemplary embodiments described above.
The first-line line head 12, which is a non-limiting example of a fluid ejecting head according to the invention, may move not together with the movable guide portion 36A of the movable guide member 36 that constitutes a part of the paper guide 34. That is, the first-line line head 12 may move independently of the movable guide portion 36A of the movable guide member 36. For example, a dedicated power source for driving the first-line line head 12 may be provided so as to move the first-line line head 12.
The invention may be applied to a line printer that has a plurality of recording heads arranged in a staggered pattern as shown in
As a user slides the movable guide portion 36A of the movable guide member 36 in the paper-width Y direction in accordance with the width size of a sheet of printing paper 20, the pair of first-line movable recording heads 81 and the pair of third-line movable recording heads 83 move together with the movable guide portion 36A of the movable guide member 36 in the paper-width Y direction while maintaining the respective head pitches. At the time when the movable guide portion 36A of the movable guide member 36 is moved to the minimum-sheet-size position, the pair of first-line movable recording heads 81 and the pair of third-line movable recording heads 83 are moved to positions illustrated in
The execution timing of flushing operation may be variable. For example, if there is not any nozzle that did not discharge ink drops even once during the flushing execution time interval, or, in other words, until the flushing set time elapses, the flushing execution time may be extended. If such a modified configuration is adopted, it is possible to defer the flushing execution timing so as to decrease the number of times of flushing operations. By this means, it is possible to narrow a paper gap that was preset (i.e., allocated) to be wide enough so as to allow flushing to be executed. In addition to or in place of the narrowing of a paper gap described above, it is possible to increase paper-feed speed that was preset to be slow enough so as to allow flushing to be executed. As a result thereof, it is possible to enhance the throughput of printing.
In the configuration of the printer 11 according to the foregoing exemplary embodiment of the invention, the paper guide 34 has the guide support member 35 having the fixed guide portion 35A and the movable guide member 36 having the movable guide portion 36A. Having such a structure, the paper guide 34 according to the foregoing exemplary embodiment of the invention offers the aforementioned one-side slide paper adjustment. However, the scope of the invention is not limited to such a specific exemplary configuration. For example, a paper guide that has the aforementioned center paper adjustment structure may be adopted. In the configuration of a center-paper-adjustment paper guide, both sides of guide portions thereof can move while keeping a center unchanged therebetween. If the configuration of such a center-paper-adjustment paper guide is adopted, the line head 12 is fixed to one of the movable guide portions in such a manner that the line head 12 can move together with the above-mentioned one of the movable guide portions whereas the line head 13 is fixed to the other of the movable guide portions in such a manner that the line head 13 can move together with the above-mentioned other of the movable guide portions. At the time when a sheet of printing paper having the maximum sheet size is set on the paper guide, the nozzle-overlap area at which the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13 overlap each other takes the minimum value, which might be zero but not limited thereto. As a gap between the above-mentioned one of the movable guide portions and the other thereof narrows, the nozzle-overlap area at which the nozzle lines 12B of the line head 12 and the nozzle lines 13B of the line head 13 overlap each other increases.
The invention is applicable as long as the N number (N>2) of fluid ejecting heads is provided and if, for example, the (N−1) number of fluid ejecting heads can move in a direction orthogonal to the transport direction of a fluid ejection target medium. The number N may be two, three or more. It should be noted that the number of fluid ejecting heads that can move in a direction orthogonal to the transport direction of a fluid ejection target medium is not limited to (N−1). That is, the invention is applicable as long as the number of fluid ejecting heads that can move in a direction orthogonal to the transport direction of a fluid ejection target medium is at least one.
In the configuration of the printer 11 according to the foregoing exemplary embodiment of the invention, it is explained that the nozzle-switchover conditions for switching over active nozzles that are actually used for printing between the first-line line head 12 and the second-line line head 13 at the nozzle-overlap area are set as the changing of print-target sheets of paper 20 due to the ejection of the current sheet of print-completed paper 20 and the feeding of the next sheet of printing paper 20. Notwithstanding the foregoing, however, the nozzle-switchover conditions may not be associated with the changing of print-target sheets of paper 20. For example, the active nozzles may be switched over once or a plural number of times during the execution of printing on a single sheet (i.e., page) of printing paper. For example, ink-landing positions on a sheet of printing paper 20 may be shifted from each other between the first-line line head 12 and the second-line line head 13.
The sizes (i.e., lengths of nozzle lines) of fluid ejecting heads measured along the direction orthogonal to the paper-transport X direction may differ from each other (or differ from one to another). The following is a non-limiting preferable example of a combination of two fluid ejecting heads that have sizes different from each other. One of two fluid ejecting heads has a size corresponding to the width of printing paper having the minimum sheet size (e.g., L paper size). The other of two fluid ejecting heads has a size corresponding to the width of printing paper having a sheet size that is equal to a difference between a regular sheet size (e.g., A4 paper size), which is larger than the minimum sheet size, and the minimum sheet size (i.e., A4 paper size-L paper size). The above-described combination of two fluid ejecting heads that have sizes different from each other offers a preferable combination head size (i.e., the lengths of nozzle lines) that ensures that the nozzle-line overlap is minimized at the time when printing is performed on a sheet of printing paper having a regular sheet size.
In the configuration of the printer 11 according to the foregoing exemplary embodiment of the invention, it is explained that a fluid ejecting head and a cap move together. However, the scope of the invention is not limited to such an exemplary configuration. For example, a fluid ejecting head only may be movable. If the cap is provided as an immovable part, the fluid ejecting head is moved to a standby position where the cap is provided at each time when flushing or cleaning is performed and at each time when the fluid ejecting head is capped so as to wait till the next execution of printing.
The type of a printer that constitutes a non-limiting example of a fluid ejecting apparatus according to the invention is not limited to a line printer. For example, the invention can be applied to a serial printer, which performs printing while moving (i.e., scanning) its recording heads in the paper-width direction. If the invention is applied to a serial printer, printing operation is performed as follows. At the time when printing is performed on a sheet of printing paper having the maximum sheet size, the relative positions of the fluid ejecting heads thereof are set in such a manner that they are distanced from each other with the maximum distance therebetween. This means that the overlap of the fluid ejecting heads is minimized at the time when printing is performed on a sheet of printing paper having the maximum sheet size. With such positional setting of the fluid ejecting heads, the serial printer performs printing on a sheet of printing paper having the maximum sheet size while moving the fluid ejecting heads in the paper-width direction, which is the main scan direction. On the other hand, at the time when printing is performed on a sheet of printing paper having the minimum sheet size, the fluid ejecting heads thereof are positioned close to each other in such a manner that they at least partially overlap each other when viewed in the paper-transport direction. With such positional setting of the fluid ejecting heads, the serial printer performs printing on a sheet of printing paper having the minimum sheet size while functioning as a line printer. The example of a fluid ejecting apparatus having a function of a serial printer described above offers the same advantageous effects as those offered by the foregoing exemplary embodiments of the invention.
In the configuration of the printer 11 according to the foregoing exemplary embodiment of the invention, it is explained that a fluid ejecting apparatus is embodied as an ink-jet recording apparatus. However, the scope of the invention is not limited to such an exemplary configuration. For example, the invention is applicable to a variety of fluid ejecting apparatuses that ejects or discharges various kinds of fluid that includes ink but not limited thereto. For example, the scope of the invention covers, without any limitation thereto, a liquid ejecting apparatus that is provided with a liquid ejecting head that ejects liquid onto a liquid ejection target medium, and in addition thereto, a liquid ejection control method that is used by such a liquid ejecting apparatus. The invention is further applicable to a fluid ejecting apparatus (and a fluid ejection control method) that ejects a liquid/liquefied matter/material that is made as a result of dispersion or mixture of particles of functional material(s) into/with liquid. The invention is further applicable to a fluid ejecting apparatus (and a fluid ejection control method) that ejects a gel substance. The invention is further applicable to a fluid ejecting apparatus (and a fluid ejection control method) that ejects a semi-solid substance that can be ejected as a fluid. It should be noted that the scope of the invention is not limited to those enumerated above. In addition to an ink-jet recording apparatus described in the foregoing exemplary embodiment of the invention, a fluid ejecting apparatuses to which the invention is applicable encompasses a wide variety of other types of apparatuses that ejects liquid or fluid in which, for example, a color material (pixel material) or an electrode material is dispersed or dissolved, though not necessarily limited thereto. Herein, the color material may be, for example, one that is used in the production of color filters for a liquid crystal display device or the like. The electrode material (i.e., conductive paste) may be, though not limited thereto, one that is used for electrode formation of an organic EL display device, a surface/plane emission display device (FED), and the like. A fluid ejecting apparatuses to which the invention is applicable further encompasses a wide variety of other types of apparatuses such as one that ejects a living organic material used for production of biochips or one that is provided with a sample ejection head functioning as a high precision pipette and ejects liquid as a sample therefrom. Further in addition, the invention is applicable to, and thus can be embodied as, a liquid ejecting apparatus that ejects, with high precision, lubricating oil onto a precision instrument and equipment including but not limited to a watch and a camera. Moreover, the invention is applicable to and thus can be embodied as a liquid ejecting apparatus that ejects liquid of a transparent resin such as an ultraviolet ray curing resin or the like onto a substrate so as to form a micro hemispherical lens (optical lens) that is used in an optical communication element or the like. Furthermore, the invention is applicable to and thus can be embodied as a liquid ejecting apparatus that ejects an etchant such as acid or alkali that is used for the etching of a substrate or the like. Further in addition, the invention is applicable to and thus can be embodied as a fluid ejecting apparatus that ejects a gel fluid (e.g., physical gel). In the description of this specification and the recitation of appended claims, the term “fluid” is defined as a broad generic concept that encompasses a variety of fluid matter/material/substance that includes but not limited to liquid matter/material/substance. Only one exception thereof is “gas-only” fluid (i.e., fluid that is made up of gas only). For example, the fluid includes, without any limitation thereto, inorganic solvent, organic solvent, solution, liquid resin, and liquid metal (e.g., metal melt).
The following is one aspect of the technical concept of the invention that can be understood from the foregoing exemplary embodiments of the invention and variation examples thereof described above.
(1) That is, without any intention to limit the scope of any of appended claims, as one aspect of the technical concept thereof, the invention can be defined as a fluid ejecting apparatus that is provided with a plurality of fluid ejecting heads that can eject a fluid onto a fluid ejection target medium and further has the following features. At the time when the plurality of fluid ejecting heads ejects the fluid onto the fluid ejection target medium, the positions of the plurality of fluid ejecting heads as viewed in a predetermined direction that intersects the transport direction of the fluid ejection target medium are fixed. In addition, at least one of the plurality of fluid ejecting heads can move in the predetermined direction that intersects the transport direction of the fluid ejection target medium so as to adjust the relative positions of the plurality of fluid ejecting heads as viewed in the predetermined direction that intersects the transport direction of the fluid ejection target medium in preparation for the ejection of the fluid onto the fluid ejection target medium. The above-described configuration applies to a line-type fluid ejecting apparatus, which is one example of the invention. The line-type fluid ejecting apparatus having the configuration described above makes it possible to effectively prevent, or at least reduce, the clogging of nozzles of fluid ejecting heads and other related problems while reducing any wasteful consumption of fluid other than for the purpose of ejection thereof onto a fluid ejection target medium.
Number | Date | Country | Kind |
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2007-168675 | Jun 2007 | JP | national |