JP2009012351A - Liquid jet apparatus and liquid injection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer and a printing method which can prolong the lifetime of a head unit by preventing a nozzle opening group constituting a head unit from being used in a partial region. <P>SOLUTION: The liquid jet apparatus comprises a first head unit 36 corresponding to the maximum paper width, and a second head unit 37 corresponding to a strip of paper. At the time of printing on a strip of paper, printing on the strip of paper is shared with the first head unit 36 and the second head unit 37 while shifting the paper feed direction to the paper width direction for every predetermined number of print sheets. Consequently, the nozzle opening group is prevented from being used in a partial region of the first head unit 36 and the lifetime of the head units 36 and 37 can be prolonged. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink jet liquid ejecting apparatus and a liquid ejecting method in which a line head is mounted as an ejecting head.

  Inkjet printers eject ink droplets from the nozzles mounted on the print head toward the printing paper to print images, etc., and can achieve high-definition printing at low cost. It is used in various devices such as printers, copiers, and facsimiles.

Such an ink jet printing apparatus can be roughly classified into a serial type and a line head type depending on the type of the print head.
In the serial type, a print head in which nozzles for ejecting ink droplets are arranged in a width smaller than the width of the paper is mounted on a carriage that can reciprocate in the width direction of the paper, and the paper is orthogonal to the conveyance direction of the printing paper. The print head is moved in the width direction to form an image for the paper width.
The line head type uses a line head in which nozzles for ejecting ink droplets are arranged in the same width as the paper width, and forms an image for the paper width at a time without moving the line head.

  Compared with the serial type, the line head type does not require the print head to move in the width direction of the printing paper, and so-called one-pass printing is possible, so that high-speed printing is possible. In addition, since there is no need for a carriage on which the print head is mounted or a drive system for moving the print head, the apparatus can be reduced in size and weight, and has various advantages such as greatly improved quietness. Yes.

  Incidentally, a normal printing apparatus is compatible with a plurality of types of printing paper having different sizes. In the case of the above-mentioned line head type printing device, the length of the head unit (number of nozzles) is set based on the maximum paper width. When printing on paper with a small width, the paper size can be selected. Only the nozzles in a part of the width area on the line head are used according to the signal and the print area instruction signal.

That is, when printing on narrow paper, only the nozzles in the area corresponding to printing on the narrow paper among the nozzles on one line head are used, but the nozzles in other areas are not used. The nozzles in the area corresponding to the printing on the narrow paper are used earlier than the nozzles in the other areas.
As a result, the deviation of the usage degree with respect to the nozzles assigned to the printing on the narrow paper becomes large. For example, the nozzles in the central printing area corresponding to printing on narrow paper have a lifetime earlier than the nozzles in the printing area on both sides, and the nozzles in the central printing area reach the lifetime. There has been a problem that the whole needs to be replaced.

Therefore, the following two techniques have been proposed in order to eliminate the drawbacks of such a line head type printing apparatus.
One is equipped with a unit moving means for moving the line head, which should originally be fixedly mounted, in the paper width direction. When printing on a narrow paper, the unit moving means prints on the narrow paper. In this technique, nozzles on the line head are moved to a position so that the nozzles on the line head are less used (for example, Patent Document 1 below).
The other is that the feeding position of the narrow paper can be changed in the width direction in various ways, so that the usage of the nozzles on the line head is not biased by the printing of the narrow paper. At the time of printing, this is a technique for adjusting the paper feed position in the width direction so as to eliminate the bias due to the degree of use until then (for example, Patent Document 2 below).

JP 2005-297510 A JP 2000-334935 A

  However, the above-mentioned two correspondences can improve the effect to some extent in terms of reducing the deviation of the usage degree of the nozzles due to the printing on the narrow paper, but it is used for almost all the nozzles of the line head. The purpose of equalizing the degree and extending the life of the entire line head was not satisfactory.

  For example, when the frequency of printing on an intermediate width sheet whose width dimension is 1/2 or more of the maximum sheet width is high, the intermediate width sheet can be used regardless of whether the line head is moved or the paper feed position is moved. The nozzles on the line head allocated for printing the area corresponding to a width exceeding 1/2 of the maximum paper width above are used continuously. For this reason, it is impossible to eliminate the uneven usage of some nozzles. Therefore, since some nozzles reach the end of their life early, the problem that the entire line head needs to be replaced cannot be avoided.

  In addition, in the printing apparatus and printing method in which the line head corresponding to the maximum sheet width is moved in the sheet width direction, there is a problem that the apparatus is enlarged due to the increase in the apparatus width.

  Accordingly, an object of the present invention is to solve the above-described problem, and the nozzle openings in other regions are not used because the degree of use is biased to the nozzle opening groups in a part of the nozzle openings constituting the head unit. The head unit has a long service life by preventing the inconvenience of reaching the end of its life, even though its usage is low and still has a sufficient life, and by equalizing the usage of each nozzle opening. A liquid ejecting apparatus and a liquid ejecting method capable of achieving the above can be provided. Furthermore, it is possible to provide a liquid ejecting apparatus and a liquid ejecting method that do not cause an increase in the size of the apparatus due to an increase in the apparatus width.

  A liquid ejecting apparatus according to the present invention that can solve the above-described problem is a liquid ejecting apparatus that ejects liquid from a nozzle opening, and corresponds to the recording medium having the maximum width among the ejectable recording media. Nozzle openings are provided corresponding to the first head unit equipped with openings and a small-width recording medium having a width narrower than that of the maximum width recording medium, and are arranged in a region where the ejection frequency is high in the maximum width direction. And a second head unit for ejecting the liquid to the narrow recording medium while shifting the feeding position of the narrow recording medium in the recording medium width direction.

  According to the liquid ejecting apparatus having this configuration, when the liquid ejecting apparatus corresponding to the recording medium having the maximum width of A3 size is continuously ejected to the recording medium having the narrower width than the recording medium having the maximum width, The paper feeding position is alternately performed by feeding the recording medium end aligned with the left end of the maximum recording medium width and feeding the recording medium end aligned with the right end of the maximum recording medium width.

At this time, for the ejection area where the recording medium width overlaps, the corresponding area of the first head unit and the corresponding area of the second head unit are alternately used, so that the first and second head units are used. All the nozzle openings which comprise can be used equally.
Accordingly, among the nozzle opening groups constituting the first and second head units, the usage degree is biased toward the nozzle opening groups in some areas, so that the nozzle openings in other areas are less used and still have a sufficient lifetime. In spite of remaining, it is possible to prevent the inconvenience that the head unit reaches the end of its life. Therefore, the life of the head unit can be extended by equalizing the degree of use of each nozzle opening. In addition, since the first head unit corresponding to the maximum recording medium width is not moved in the recording medium width direction, the apparatus size is not increased due to an increase in the apparatus width.
Note that the number of second head units is not limited to one, and a plurality of second head units may be provided.

Further, it is preferable that the second head unit is configured to be movable in the recording medium width direction when the liquid is not ejected.
With this configuration, for example, when continuously ejecting a recording medium having a maximum width of a recording medium having a width that is narrower than the maximum width, the feeding position is set to the maximum recording medium width every predetermined number of sheets. It is possible to perform paper feeding in which the paper feeding position is shifted by a fixed width from the paper feeding with the recording medium edge aligned to the left edge to the right edge of the maximum recording medium width. At this time, it is possible to move the second head unit in accordance with the change in the paper feed position, and to share a part of the jets in the overlapping jet region with the second head unit. Therefore, it is possible to flexibly cope with equalization of the usage degree of each nozzle opening by using a plurality of head units in combination.

In addition, the recording means for storing the cumulative number of times of use for each nozzle opening of the first and second head units is compared with the number of times of cumulative use for each nozzle opening of the first and second head units. Alternatively, it is preferable to include a paper feed position switching unit that switches the paper feed position of the narrow-width recording medium in an ejection area formed by a nozzle opening with a small cumulative number of times of use on the second head unit.
According to this configuration, in addition to the functions and effects of the liquid ejecting apparatus described above, the following functions and effects can be obtained.

That is, the continuous ejection of the narrow-width recording medium is executed with a predetermined number or less of the paper feed position to be switched, or the narrow-width recording medium is discontinuously (intermittently) ejected. When a deviation in the degree of use occurs in a part of the nozzle openings constituting the head unit of 2, the deviation in the degree of use between the nozzles is grasped from the cumulative number of uses stored for each nozzle opening. Is possible. As a result, at the time of the same ejection thereafter, the feeding position switching means switches the feeding position of the narrow recording medium to the ejection area by the nozzle opening with a small cumulative number of use times of the first or second head unit, It is possible to eliminate the bias in the degree of use that has occurred in a part of the nozzle openings constituting the first or second head unit.
Therefore, even if the ejection onto the narrow recording medium is not performed in units of a predetermined number of sheets for which the feed position is to be switched, the length of the head unit can be increased by equalizing the degree of use of the nozzle openings of the first and second head units. Life can be extended.

Further, the recording means for storing the cumulative discharge amount for each nozzle opening of the first and second head units and the cumulative discharge amount for each nozzle opening of the first and second head units are compared, and the first It is preferable to include a paper feed position switching unit that switches the paper feed position of the narrow-width recording medium in an ejection region by a nozzle opening with a small cumulative discharge amount on the first or second head unit.
According to this configuration, the life of the nozzle openings constituting each head unit is affected not only by the number of ink droplet ejections but also the ink droplet ejection amount. It is also effective to manage by recording, and it is possible to grasp the deviation in the degree of use between the nozzles by the accumulated discharge amount stored for each nozzle opening. Thus, by switching the feeding position of the narrow recording medium to the ejection area by the nozzle openings with a small cumulative discharge amount, it is possible to eliminate the uneven usage of the nozzle openings of the head units. Therefore, as in the case of the liquid ejecting apparatus described above, even if the ejection of the narrow recording medium is not performed in units of a predetermined number of sheets that are targets for switching the paper feeding position, each nozzle opening of the first and second head units is The life of the head unit can be extended by equalizing the degree of use.

  The liquid ejecting method according to the present invention capable of solving the above-described problems is a liquid ejecting method for ejecting liquid from a nozzle opening, and the nozzle corresponding to the recording medium having the maximum width among the ejectable recording media. Accumulation for each nozzle opening of the first head unit equipped with an opening and the second head unit equipped with a nozzle opening corresponding to a recording medium having a narrow width that is at least narrower than the maximum width recording medium The number of times of use is stored in the recording means, and when the liquid is ejected onto the narrow-width recording medium, the cumulative number of times of use for each nozzle opening is compared, and the first or second nozzle opening having a nozzle number with a small cumulative number of times of use is compared. An ejection area of the head unit is calculated, and an ejection process is executed after changing the paper feed position of the narrow recording medium to the calculated ejection area.

  According to the liquid ejecting method having this configuration, the liquid ejecting apparatus can be implemented by the above-described liquid ejecting apparatus, and by performing the liquid ejecting method, as described in the operational effects of the liquid ejecting apparatus, the ejection onto the narrow-width recording medium can be performed. Even if it is not the unit of the predetermined number of sheets for which the paper feed position is to be switched, the deviation in the degree of use occurring between the nozzle openings of the first and second head units from the cumulative number of uses recorded in the storage means Can be grasped. The feeding position of the narrow recording medium can be changed so that the ejection area of the first or second head unit having a nozzle opening with a small cumulative number of uses is used. Accordingly, it is possible to extend the life of each head unit by eliminating the uneven usage of the nozzle openings of the first and second head units and equalizing the usage of the nozzle openings.

  In addition, a liquid ejecting method according to the present invention that can solve the above-described problem is a liquid ejecting method that ejects liquid from a nozzle opening, and corresponds to a recording medium having the maximum width among the ejectable recording media. Nozzle openings of each of the first head unit equipped with the nozzle openings and the second head unit equipped with nozzle openings corresponding to at least a narrow recording medium narrower than the maximum width recording medium. The cumulative discharge amount for each nozzle opening is stored in the recording means, and when the liquid is ejected to the narrow-width recording medium, the cumulative discharge amount for each nozzle opening is compared, and the first or the nozzle opening having a small cumulative discharge amount is provided. The ejection area of the second head unit is calculated, and the ejection process is executed after changing the paper feed position of the narrow recording medium to the calculated ejection area.

  According to the liquid ejecting method of this configuration, the liquid ejecting apparatus described above can be implemented, and by performing the liquid ejecting method, as described in the operation effect of the liquid ejecting apparatus, the ejection of the narrow-width recording medium is performed. Even if it is not the unit of the predetermined number of sheets for which the paper feed position is to be switched, the deviation in the degree of use occurring between the nozzle openings of the first and second head units is calculated from the cumulative discharge amount recorded in the storage means. I can grasp it. The feeding position of the narrow recording medium can be changed so that the ejection area of the first or second head unit having a nozzle opening with a small cumulative discharge amount is used. Accordingly, it is possible to extend the life of each head unit by eliminating the uneven usage of the nozzle openings of the first and second head units and equalizing the usage of the nozzle openings.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a liquid ejecting apparatus and a liquid ejecting method according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic side view of a printing apparatus which is a first embodiment of a liquid ejecting apparatus according to the present invention, and FIG. 2 is an explanatory diagram showing the relationship between the configuration of a print head of the printing apparatus of FIG. 3 is an explanatory diagram of the width dimension of the second head unit shown in FIG. 2, and FIG. 4 is an explanatory diagram of the operation of the second head unit and the distribution of the feeding position of the narrow paper when printing the narrow paper. FIG. 5 is a flowchart showing the procedure of the printing method performed by the printing apparatus shown in FIG.

  The printing apparatus 10 according to the embodiment includes a paper tray 13 for storing printing paper (recording paper) S, an image recording unit 16 having an ink jet print head 11, and a paper tray. 13 is fed one by one to the front image recording unit 16 side, and the printing paper S fed by the paper feeding unit 15 is passed through the image recording unit 16 to the discharge port 18. A transport unit 14 for sending out and a control unit 17 for controlling the driving of each unit are provided.

  The housing 12 is formed in a rectangular parallelepiped box shape. A discharge port 18 for discharging the printing paper S after the printing process is provided on the wall surface in the insertion direction of the paper tray 13. In addition, a tray attachment / detachment opening 19 for attaching / detaching the paper tray 13 is provided on the wall surface behind the paper tray 13 in the insertion direction.

  The conveyance unit 14 is provided between the front end of the paper tray 13 and the discharge port 18, a paper feed guide 20 serving as a guide surface for feeding the printing paper S, and between the paper feed guide 20 and the front end of the paper tray 13. A first paper feed roller pair 21 that sandwiches the print paper S fed from the paper tray 13 by a pair of rollers and feeds it onto the paper feed guide 20. A second paper feed roller pair 22 is provided between the paper feed guide 20 and the discharge port 18 and sandwiches the printing paper S on the paper feed guide 20 between a pair of rollers and feeds the print paper S to the discharge port 18. In addition, pulleys 23 and 24 for driving these paper feed roller pairs 21 and 22, a transport unit drive motor 25 disposed below the paper feed guide 20, and a driving force of the transport unit drive motor 25 is applied to the pulleys 23 and 24. Belts 26 and 27 for transmitting to 24.

  The paper feed guide 20 is formed in a flat plate shape and serves as a transport surface for transporting the print paper S. At the same time, the paper feed guide 20 is disposed below the print head 11 with a predetermined gap and holds the print paper S during the printing process. Providing a plane.

  The paper supply unit 15 is disposed above the front end of the paper tray 13. The paper supply unit 15 is in contact with the print paper S in the paper tray 13 and supplies the print paper S to the first paper feed roller pair 21 one by one, and a drive source that rotationally drives the supply roller 28 And a gear 29 that transmits the output of the supply motor 30 to the supply roller 28.

  The supply roller 28 is formed in a substantially semi-cylindrical shape, and is provided in the vicinity of the first paper feed roller pair 21. The supply unit motor 30 is disposed above the supply roller 28.

  The paper tray 13 is formed in a box shape that can accommodate a large number (for example, several hundreds) of printing paper S in a stacked state, and is detachably mounted in a space extending from the lower side of the paper supply unit 15 to the tray attachment / detachment opening 19. Has been. The paper tray 13 is provided with a paper support 32 biased upward by a spring 31 at a position near the front end of the bottom surface, and the printing paper accommodated by the elastic displacement of the paper support 32 upward. The uppermost S is brought into contact with the supply roller 28.

The printing apparatus 10 according to the present embodiment basically deals with A3 and A4 sizes as the printing paper S, but also handles B4 and B5 paper having a smaller width than these sizes. Is possible.
The width dimension of the paper tray 13 is set in accordance with the A3 size which is the maximum paper width so that any of these sizes of paper can be accommodated.

  In the case of the present embodiment, a small width sheet (for example, A4) in which the width of the print sheet S supplied to the image recording unit 16 is narrower than the maximum sheet width is provided in one of the transport unit 14 and the sheet tray 13 described above. 3 or B5 size paper), the paper feed position to the image recording unit 16 is moved by an appropriate dimension in the width direction within the width W1 when the A3 size paper is conveyed, as shown in FIG. A paper feed position switching means 61 is provided.

As shown in FIG. 3, this paper feed position switching means 61 supports a pair of width adjusting guides 62 and 63 for regulating the positions of both side edges of a narrow paper so as to be movable in the paper width direction by a traverse mechanism (not shown). It is a thing.
Specifically, when the small width sheet is an A4 size sheet, the sheet feed position switching unit 61 sets the sheet feed position to the right end within the width W1 when the A3 size sheet is conveyed. It is possible to switch to Rq or the paper feed position Lq brought to the left end.

  Further, in the case of a B5 size paper having a smaller width dimension, the paper feed position switching means 61, as shown in FIG. 4, is multi-step from the right end to the left end within the width W1 during A3 size paper transport. The paper feed position can be switched.

  The operation of switching the paper feed position by the paper feed position switching means 61 is executed when printing is not performed in the image recording unit 16.

The control unit 17 is an electronic control unit (ECU) incorporating various electronic components, and is disposed above the paper tray 13.
The control unit 17 is electrically connected to the print head 11, the conveyance unit drive motor 25, and the supply unit motor 30, and controls these operations. The control unit 17 incorporates a head unit controller 33 that mainly controls the operation of the print head 11.

  As shown in FIG. 2, the print head 11 corresponds to the first head unit 36 provided with a nozzle opening corresponding to the maximum paper width in the head case 35, and small width paper narrower than the maximum paper width. Thus, a second head unit 37 is provided which is equipped with a nozzle opening and is arranged in a central region where the printing frequency in the maximum paper width direction is high. Note that the number of second head units is not limited to one, and a plurality of second head units may be provided.

  The first head unit 36 has a large number of nozzle openings arranged in the paper width direction corresponding to the paper width when the A3 size printing paper S1 is vertically fed.

  As shown in FIG. 3, the second head unit 37 includes an A4 size printing sheet S2 brought close to the right end of the width W1 and an A4 size printing sheet approaching the left end of the width W1. A number of nozzle openings are arranged in the paper width direction corresponding to the width W2 of the central region where S2 overlaps each other.

  In the case of the present embodiment, the second head unit 37 is supported by a guide rail 38 provided in the head case 35 so as to be movable in the paper width direction within the width of the first head unit 36. . When the printer is not printing, it can be moved to an arbitrary position in the print width direction.

Further, each of the head units 36 and 37 is for color printing, and is shifted in the sheet feeding direction, and nozzle rows for four colors are arranged.
In each head unit 36, 37, the nozzle rows 36 a, 37 a are configured by arranging nozzle openings 41 for ejecting cyan (C) ink at a constant pitch in the corresponding paper width. The nozzle rows 36b and 37b are configured such that nozzle openings 42 for ejecting magenta (M) ink are arranged at a constant pitch in the corresponding paper width. The nozzle rows 36c and 37c are configured such that nozzle openings 43 for ejecting yellow (Y) ink are arranged at a constant pitch in the corresponding paper width. The nozzle rows 36d and 37d are configured such that nozzle openings 44 for ejecting black (K) ink are arranged at a constant pitch in the corresponding paper width.

  Each head unit 36, 37 realizes full color printing by superimposing ink droplets ejected from the respective color nozzle openings 41 to 44 on the printing paper S and adjusting the amount of each color to be applied. To do.

  In the case of the present embodiment, the head unit controller 33 that controls the operation of each head unit 36, 37 includes a storage means 51 that stores the cumulative number of use for each nozzle opening of each head unit 36, 37, and a small width When printing on paper, a paper feed position control means 53 is provided for controlling the operation of the paper feed position switching means 61 based on the cumulative number of times used for each nozzle opening of the head units 36 and 37 stored in the storage means 51. ing.

  The paper feed position control means 53 compares the cumulative number of uses for each nozzle opening of each head unit 36, 37 stored in the storage means 51, and the first or second head having a nozzle opening with a small cumulative number of uses. The print area on the units 36 and 37 is calculated, and the paper feeding position of the narrow paper is switched to the print area with the nozzle openings having a small cumulative use count. At that time, the paper position control means 53 has a print area with a nozzle opening with a small cumulative use frequency on the second head unit 37 and a print area with a nozzle opening with a low product use frequency on the first head unit 36. In order not to overlap, control is also performed to move the second head unit 37 in the paper width direction when not printing.

  Next, in the printing apparatus 10 described above, a method for printing on a small-width sheet that is performed by operation control by the head unit control unit 33 of the control unit 17 will be described.

  As shown in FIG. 5, the head unit control unit 33 performs a printing process when print data (consisting of a print command and image information to be printed) is input from an input device (such as a computer) (not shown). To implement.

  That is, first, when print data is input to the narrow paper (step S101), the print size is recognized from the paper size information in the print data (step S102), and the print paper stored in the paper tray 13 is displayed. The paper width of S is recognized by automatic recognition by a sensor (not shown) provided in the housing 12 or by the guide position of the paper tray 13 (step S103).

Next, from the information recorded in the storage means 51, the cumulative use frequency of each nozzle opening of the first or second head unit 36, 37 is compared (step S104). From the comparison of the cumulative number of times of use, each head unit 36, so that the print area by the nozzle opening with the small cumulative number of times of use on the first or second head unit is calculated and the calculated print area is used. The used nozzle opening on 37 is determined (step S105).
Next, the paper feed position switching means 61 switches the paper feed position of the print paper S fed from the paper tray 13 to the image recording unit 16 so as to meet the nozzle opening printing area determined in step S105 (step S106). ).

  Next, print data (image data) is output to the nozzle openings of the head units determined in step S105 (step S107), and paper feeding from the paper tray 13 to the image recording unit 16 is performed in conjunction therewith. . Then, printing is executed by ejecting ink droplets from the nozzle openings on the head unit in synchronization with the feeding speed of the paper feed (step S108). Then, the nozzle opening used for ejecting the ink droplet is counted for the number of times of use, and the cumulative number of times of use stored in the storage means 51 is updated (step S109).

  When printing continuously on paper of the same size, the process returns from step S109 to step S104, and the same processing is repeated.

  The printing method shown in FIG. 5 can be summarized as follows. The first head unit 36 equipped with the nozzle openings corresponding to the maximum paper width W1 and the nozzle openings corresponding to the small width paper narrower than the maximum paper width. Is stored in the storage means 51 for each nozzle opening with the second head unit 37 equipped with. Then, when printing on a narrow paper, the print area of the first or second head unit 36, 37 having a nozzle opening with a small cumulative use count is calculated by comparing the cumulative use count for each nozzle opening, Printing is executed after changing the paper feeding position of the narrow paper in the calculated printing area.

According to the printing method executed by the printing apparatus 10 described above, in the printing apparatus 10 in which the maximum sheet width is A3 size printing sheet S1 as shown in FIG. 2, the maximum sheet width is larger than the maximum sheet width as shown in FIG. When continuously printing A4 size printing paper S2, which is a narrow paper with a narrow width, as shown in the drawing, the paper feeding position is set to the left edge of the maximum paper width W1, and the paper feeding position is set to the maximum for every predetermined number of sheets. Paper feeding is performed alternately at the right end of the paper width W1.
At this time, for the print area having the width W2 of the central area where the paper widths overlap, the corresponding area of the first head unit 36 and the corresponding area of the second head unit 37 are alternately used every predetermined number of sheets. As a result, all nozzle openings constituting the first and second head units 36 and 37 can be used uniformly.

Therefore, among the nozzle opening groups constituting the first and second head units 36 and 37, the usage degree is biased toward the nozzle opening groups in some areas, so that the nozzle openings in other areas are less used. It is possible to prevent the occurrence of inconvenience that the head unit reaches the end of its life even though a sufficient end of life remains. Therefore, the life of the head units 36 and 37 can be extended by equalizing the degree of use of each nozzle opening.
In addition, since the first head unit 36 corresponding to the maximum sheet width is not moved in the sheet width direction, the apparatus is not enlarged due to the increase in the apparatus width.

Further, in the printing apparatus 10 of the present embodiment, the second head unit 37 is movable in the paper width direction when printing is not being performed.
Therefore, for example, the printing apparatus 10 of the printing sheet S1 having the maximum sheet width A3 size continuously prints the printing sheet S3 of B5 size, which is a narrow sheet narrower than the maximum sheet width, as shown in FIG. In this case, for each predetermined number of sheets, the sheet feeding position is shifted from the sheet feeding position where the sheet edge is aligned to the left end of the maximum sheet width W1 to the right end side of the maximum sheet width W1 by shifting the sheet feeding position by a fixed width. Accordingly, it is possible to move the second head unit 37 in accordance with the change of the paper feed position, and to share the printing of a part of the overlapping print area with the second head unit. It becomes possible to respond more flexibly to the equalization of the usage level of.
Note that the number of second head units is not limited to one, and a plurality of second head units can be provided, and if they are movable, the overlapping print areas can be flexibly shared by more head units.

  Furthermore, in the printing apparatus 10 of the present embodiment, the storage means 51 that stores the cumulative number of times of use for each nozzle opening of the first and second head units 36 and 37, the first and second head units 36, 37, the cumulative number of times of use for each nozzle opening is compared, and the paper feed position for switching the paper feed position of the narrow paper to the printing area by the nozzle opening with the smallest cumulative number of times of use on the first or second head unit 36, 37 is switched. Position switching means 61 is provided.

Therefore, the following actions / effects can be further obtained.
That is, the continuous printing of the narrow paper is executed with a predetermined number or less of the paper feed position to be switched, or the first or the second is executed by performing discontinuous (intermittent) printing of the narrow paper. When a deviation in the degree of use occurs in a part of the nozzle openings constituting the head units 36 and 37, the degree of use between the nozzles is determined from the cumulative number of uses stored for each nozzle opening in the storage means 51. It becomes possible to grasp the bias. As a result, during the subsequent printing, the paper feed position switching unit 61 switches the paper feed position of the narrow paper to the print area by the nozzle opening with the small cumulative number of use times of the first or second head unit 36, 37. Thus, it is possible to eliminate the uneven use degree generated in a part of the nozzle openings constituting the first or second head unit 36 or 37.
Therefore, even if printing of narrow paper is not performed in units of a predetermined number of sheets for which the paper feed position is to be switched, each head unit can be obtained by equalizing the degree of use of the nozzle openings of the first and second head units 36 and 37. It is possible to extend the life of 36 and 37.

In the printing apparatus and printing method according to the present invention, the method of managing the degree of use in each head unit is not limited to the method of recording the cumulative number of times of use of each nozzle opening shown in the above embodiment.
For example, the head unit controller 33 is equipped with storage means for storing the accumulated discharge amount for each nozzle opening of each head unit 36, 37 instead of the storage means 51 shown in the above embodiment. Further, instead of the paper feed position control means 53 shown in the above embodiment, the cumulative discharge quantity for each nozzle opening of each head unit 36, 37 stored in the storage means is compared, and the discharge quantity of each head unit is compared. It may be configured to include a paper feed position control means for switching the paper feed position of the narrow paper in a printing area with a small number of nozzle openings.

At the time of the printing process, as shown in steps S204, S205, and S206 in FIG. 6, the cumulative discharge amounts of the head units are compared to determine a print area with a nozzle opening with a small cumulative discharge quantity, and the print area It is preferable to print by switching the paper feed position so that narrow paper is fed.
Note that the printing method shown in FIG. 6 employs a cumulative discharge amount instead of the cumulative number of times used in the printing method shown in FIG. 5 as data indicating the degree of use of the nozzle openings. This is the same as the printing method shown in FIG.

  That is, the printing method shown in FIG. 6 is equipped with the first head unit 36 provided with nozzle openings corresponding to the maximum paper width W1 and the nozzle openings corresponding to narrow paper narrower than the maximum paper width. The accumulated discharge amount for each nozzle opening with the second head unit 37 is stored in the storage means 51. Then, when printing on narrow paper, the accumulated discharge amount for each nozzle opening is compared to calculate the print use area of the first or second head unit 36, 37 having a nozzle opening with a small accumulated discharge amount. Thus, printing is executed after changing the feeding position of the narrow paper in the calculated printing area.

Since the life of the nozzle openings constituting each head unit 36, 37 is affected not only by the number of ink droplet ejections but also the amount of ink droplet ejection, the usage degree of each nozzle opening is recorded by recording the cumulative ejection amount. It is also effective to manage. Therefore, it is possible to grasp the deviation of the degree of use between the nozzles based on the accumulated discharge amount stored for each nozzle opening. Thereby, by switching the paper feeding position of the narrow paper to the printing area by the nozzle openings with a small cumulative discharge amount, it is possible to eliminate the uneven usage of the nozzle openings of the head units 36 and 37.
Accordingly, as in the case of the printing apparatus 10 described in the first embodiment, the first and second head units can be printed even when printing on narrow paper is not performed in units of a predetermined number of sheets for which the paper feed position is to be switched. The life of the head unit can be extended by equalizing the degree of use of the nozzle openings 36 and 37.

1 is a schematic side view of a first embodiment of a printing apparatus according to the present invention. FIG. 2 is an explanatory diagram showing a relationship between a configuration of a print head of the printing apparatus of FIG. 1 and a corresponding paper width. It is explanatory drawing of the width dimension of the 2nd head unit shown in FIG. It is explanatory drawing of operation | movement of the 2nd head unit at the time of printing a narrow paper, and distribution of the feeding position of a narrow paper. 3 is a flowchart illustrating a procedure of a printing method performed by the printing apparatus illustrated in FIG. 1. It is a flowchart of other embodiment of the printing method implemented with the printing apparatus which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printing apparatus, 11 ... Print head, 12 ... Housing | casing, 13 ... Paper tray, 16 ... Image recording part, 17 ... Control unit, 33 ... Head unit control part, 36 ... 1st head unit, 37 ... Difference 2 Head units 36a, 36b, 36c, 36d ... nozzle rows, 37a, 37b, 37c, 37d ... nozzle rows, 41, 42, 43, 44 ... nozzle openings, 51 ... storage means, 53 ... paper feed position control means, 61: paper feed position switching means, 62, 63: width alignment guide, S ... printing paper, S1 ... A3 size printing paper, S2 ... A4 size printing paper, S3 ... B5 size printing paper.

Claims (6)

A liquid ejecting apparatus that ejects liquid from a nozzle opening,
A first head unit equipped with the nozzle opening corresponding to the recording medium having the maximum width among the jettable recording media;
A second head unit that is equipped with a nozzle opening corresponding to a recording medium having a narrow width that is at least narrower than the recording medium having the maximum width, and is arranged in a region where the ejection frequency is high in the maximum width direction,
A printing apparatus that ejects a liquid feeding position onto the narrow recording medium while shifting a feeding position of the narrow recording medium in a recording medium width direction. The liquid ejecting apparatus according to claim 1,
A printing apparatus, wherein the second head unit is movable in the recording medium width direction when liquid is not ejected. The liquid ejecting apparatus according to claim 1 or 2,
Recording means for storing the cumulative number of times used for each nozzle opening of the first and second head units;
The cumulative number of times of use of each nozzle opening of the first and second head units is compared, and the narrow-width recording medium is fed to the ejection region by the nozzle opening having a small cumulative number of times of use on the first or second head unit. A liquid ejecting apparatus comprising: a paper feed position switching unit that switches positions. The liquid ejecting apparatus according to claim 1 or 2,
Recording means for storing the cumulative discharge amount for each nozzle opening of the first and second head units;
The cumulative discharge amount for each nozzle opening of the first and second head units is compared, and the supply of the narrow-width recording medium to the ejection region by the nozzle opening having a small cumulative discharge amount on the first or second head unit is performed. A liquid ejecting apparatus comprising: a paper feed position switching unit that switches a paper position. A liquid ejection method for ejecting liquid from a nozzle opening,
Among the jettable recording media, the first head unit provided with the nozzle opening corresponding to the maximum width recording medium and the small width recording medium narrower than the maximum width recording medium. The recording means stores the cumulative number of times used for each nozzle opening with the second head unit equipped with the nozzle openings,
At the time of liquid ejection onto the narrow-width recording medium, the cumulative number of uses for each nozzle opening is compared, and the ejection area of the first or second head unit having a nozzle opening with a small cumulative number of uses is calculated. A liquid ejecting method, comprising: performing an ejection process after changing a paper feeding position of the narrow recording medium to the calculated ejection area. A liquid ejection method for ejecting liquid from a nozzle opening,
Among the jettable recording media, the first head unit provided with the nozzle opening corresponding to the maximum width recording medium and the small width recording medium narrower than the maximum width recording medium. The cumulative discharge amount for each nozzle opening with the second head unit equipped with the nozzle openings is stored in the recording means,
At the time of liquid ejection onto the narrow-width recording medium, the cumulative ejection amount for each nozzle opening is compared, the ejection area of the first or second head unit having a nozzle opening with a small cumulative ejection amount is calculated, A liquid ejecting method, comprising: performing an ejection process after changing a paper feeding position of the narrow recording medium to the calculated ejection area.

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