JP2019177675A - Liquid discharge device and liquid discharge method - Google Patents

Abstract

To provide a liquid discharge device and liquid discharge method which can reduce the cost of a liquid absorber to receive liquid on the outer side of a recording medium.SOLUTION: A liquid discharge device includes: a plurality of heads which have a plurality of nozzles arrayed along the first direction, and are arranged so as to have an overlapping region with an adjacent head along the first direction when seen through from the second direction orthogonal to the first direction; and a control unit which replaces the first idle discharge operation performed for maintenance in the non-image formation region corresponding to the liquid absorber with the partial nozzles of the two or more nozzles included in the overlapping region in the plurality of heads with the second idle discharge operation performed for maintenance in the image formation region corresponding to the recording medium.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a liquid ejection apparatus and a liquid ejection method.

  In a liquid ejecting apparatus having a head for ejecting liquid onto a recording medium, a thickened liquid may stay in the head, and a flushing process for ejecting the liquid is performed to remove the retained liquid.

  In Patent Document 1, in an ink jet printer, a portion of a region where an ink landing amount is expected to be large is formed of a porous member having a high absorption rate in an ink absorber on which ink droplets ejected to the outside of the paper are landed. However, it is described that a portion of a region where the ink landing amount is expected to be small is formed of a porous member having a low absorption rate. Thereby, according to Patent Document 1, it is said that the ink absorption capability can be improved while maintaining the ink holding capability of the ink absorber as much as possible.

  However, in the technique described in Patent Document 1, an ink absorber is formed by combining a plurality of porous members having different absorptances. Therefore, an ink absorber that should receive ink (liquid) outside a sheet (recording medium) ( The cost of the liquid absorber may increase.

  The present invention has been made in view of the above, and an object of the present invention is to provide a liquid ejecting apparatus and a liquid ejecting method that can reduce the cost of a liquid absorber that should receive liquid outside a recording medium.

  In order to solve the above-described problems and achieve the object, a liquid ejection device according to one aspect of the present invention has a plurality of nozzles arranged along a first direction, and the first direction. A plurality of heads arranged so that an overlapping region is formed with an adjacent head along the first direction when viewed from a second direction orthogonal to the first direction, and 2 included in the overlapping region in the plurality of heads The first idle ejection operation performed for maintenance in the non-image forming area corresponding to the liquid absorber by some of the nozzles is performed for maintenance in the image forming area corresponding to the recording medium. And a controller that replaces the idle discharge operation.

  According to the present invention, it is possible to reduce the cost of the liquid absorber that should receive the liquid outside the recording medium.

FIG. 1 is a cross-sectional view illustrating a configuration of a liquid ejection apparatus according to an embodiment. FIG. 2 is a side view showing the configuration of the liquid ejection head module in the embodiment. FIG. 3 is a plan view showing the configuration of the liquid ejection unit in the embodiment. FIG. 4 is an enlarged bottom view showing the configuration of the liquid ejection head in the embodiment. FIG. 5 is an exploded perspective view showing the configuration of the liquid ejection head in the embodiment. FIG. 6 is a plan view illustrating an image of landing on the liquid absorber when the flushing process is performed without replacing the idle ejection operation in the embodiment. FIG. 7 is a plan view illustrating an overlapping region between a plurality of liquid ejection heads in the embodiment. FIG. 8 is a plan view showing an image of landing on the liquid absorber when the flushing process is performed by replacing the idle ejection operation in the embodiment. FIG. 9 is a block diagram illustrating a configuration relating to control of the liquid ejection apparatus according to the embodiment. FIG. 10 is a block diagram illustrating a functional configuration of the control unit in the embodiment.

  Hereinafter, a liquid ejection apparatus according to an embodiment will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment.

(Embodiment)
The liquid ejection device according to the embodiment is a device for ejecting liquid. The liquid ejecting apparatus can be applied to an image forming apparatus that ejects liquid onto a recording medium to form pixels on the recording medium. For example, the liquid ejecting apparatus is an ink jet recording apparatus, the liquid is ink, and the recording medium is paper. A liquid ejection apparatus (inkjet recording apparatus) forms a plurality of pixels by ejecting droplets (ink droplets) from a plurality of nozzles of a liquid ejection head (inkjet head) onto the surface of a supplied recording medium (recording paper). To do. In this type of apparatus, there are nozzles with a low ejection frequency depending on the image data, but the thickened liquid may stay in these nozzles. The liquid ejection apparatus performs a flushing process (preliminary ejection process) for ejecting liquid to remove the staying liquid on the nozzles.

  This flushing process is a laminating process in which liquid is idlely ejected with a line-shaped dot pattern from a plurality of nozzles in the liquid ejection head during a period in which the non-image forming area (area between print pages) is located at the ejection position of the liquid ejection head. It is conceivable to carry out the operation (first idle ejection operation). For example, when a labyrinth is carried out on a recording medium (paper) with a liquid absorber (ink absorber), if the absorption amount of the liquid absorber reaches a certain amount at a certain frequency, absorption is performed. Since the capability deteriorates, it is necessary to replace the liquid absorber.

  When the flushing process is performed by the labyrinth operation, the liquid landing amount on the liquid absorber is likely to vary depending on the arrangement of the liquid discharge heads. When the dispersion of the liquid landing amount becomes large, when the absorption amount of the portion where the liquid landing amount is large in the liquid absorber reaches a certain amount, the absorption amount of the portion where the liquid landing amount is small in the liquid absorber reaches a certain amount. Despite not doing so, the liquid absorber will be replaced. Thereby, the replacement frequency of the liquid absorber is likely to increase, and the running cost of the liquid absorber may increase.

  Further, a portion of the liquid absorber that is expected to have a large amount of liquid landing is formed of a porous member having a high absorption rate, and a portion of the region that is expected to have a low liquid landing amount is a porous member having a low absorption rate. It is possible to form with. Thereby, since deterioration of the absorption capacity of the liquid absorber can be suppressed, it is conceivable that the replacement frequency of the liquid absorber can be reduced and the running cost of the liquid absorber can be reduced. In this case, since the liquid absorber is formed by combining a plurality of porous members having different absorption rates, the production cost of the liquid absorber may increase.

  Therefore, in the present embodiment, in the liquid ejection device, the idle ejection operation by some of the two or more nozzles included in the region where the liquid landing amount in the liquid absorber is large is changed from the idle ejection operation with a large ejection amount to the ejection amount. By performing the flushing process instead of the idle discharge operation with a small amount, the dispersion of the liquid landing amount in the liquid absorber is suppressed, and the cost of the liquid absorber is reduced.

  Specifically, the liquid absorber has a portion where the liquid landing amount increases due to the head arrangement. In a line head type liquid ejecting apparatus (inkjet recording apparatus) in which a plurality of heads are arranged in a staggered manner, for example, the plurality of heads are formed so that overlapping regions are formed along the nozzle arrangement direction when seen through from the transport direction. Has been placed. When the laminating operation is performed on the liquid absorber (ink absorber) in the non-image forming region (the region between papers) with this liquid ejection device, the location in the liquid absorber corresponding to the overlapping region of the plurality of heads Will increase the amount of liquid landing. For this reason, the liquid ejecting apparatus performs the idle ejection operation on the non-image forming area (the area between the print pages) by some of the two or more nozzles in the overlapping area from the labyrinth operation to the image forming area (in the print page). It is replaced with the star flushing operation which is the flushing performed in the area. In the labyrinth operation, since the liquid is densely discharged in a line shape, the amount of liquid discharged per unit area is large. In the star flushing operation, small droplets (ink droplets) that are not visible are ejected sparsely in a star shape, so that the amount of liquid ejected per unit area is small. Thereby, since the dispersion | variation in the liquid landing amount (ink landing amount) to a liquid absorber (ink absorber) can be suppressed, the expense accompanying replacement | exchange of a liquid absorber can be reduced. Alternatively, an increase in manufacturing cost due to a complicated configuration of the liquid absorber can be avoided.

  More specifically, the liquid ejection device 200 is configured as shown in FIG. FIG. 1 is a cross-sectional view showing the configuration of the liquid ejection device 200. FIG. 1 illustrates a configuration when the liquid ejection apparatus 200 is an image forming system such as an on-demand line head type inkjet recording apparatus.

  The liquid ejection apparatus 200 includes an image forming unit 210, a paper feeding unit 220, a registration adjusting unit 230, a drying unit 240, a recording medium reversing unit 250, and a paper discharge unit 290. An example of the flow during printing will be described. First, the recording media 1 loaded on the paper feed stack 221 of the paper feed unit 220 are picked up one by one by the air separation unit 222 and conveyed toward the image forming unit 210. . When the recording medium 1 conveyed from the paper supply unit 220 reaches the registration adjusting unit 230, the registration adjusting unit 230 corrects the inclination of the recording medium 1 by a registration roller pair 231 provided therein.

  The registration-adjusted recording medium 1 is sent to the image forming unit 210, and the recording medium gripper 11 provided on the surface of the drum 10 on the cylindrical shape sandwiches the leading end of the recording medium 1, and the drum 10 rotates to discharge liquid. It is conveyed to a position facing the unit 8. The liquid ejection unit 8 includes a plurality of liquid ejection head modules (a plurality of head arrays) 28 corresponding to a plurality of colors. The plurality of liquid discharge head modules 28 may be described as a plurality of liquid discharge head modules 28K to 28P in order to distinguish the colors corresponding to each other.

  In the image forming unit 210, along the surface of the cylindrical drum 10, the liquid discharge units 8 that discharge liquid (ink) by an ink jet method are arranged radially with an angle filled with a predetermined ink color. The liquid ejection unit 8 (the plurality of liquid ejection head modules 28K to 28P) ejects liquid (ink) from the outer circumference to the outer peripheral surface of the recording medium 1 held on the surface of the drum 10, thereby recording the recording medium. An image is formed on 1.

  An empty discharge receiver 12 is provided on the outer peripheral surface of the cylindrical upper drum 10, and the empty discharge operation is performed when the liquid discharge unit 8 does not discharge liquid (ink) for image formation onto the recording medium 1. Thus, the liquid (ink) discharged (empty discharge) from the liquid discharge unit 8 is received. The idle discharge receiver 12 has a liquid absorber (ink absorber) 12a. The liquid absorber 12a is formed of a material (for example, a porous body) that can receive and absorb liquid (ink) outside the recording medium (recording paper) 1.

  When an image is formed on the recording medium 1, the recording medium 1 is sent to the drying unit 240. A drying unit 241 is attached to the drying unit 240, and the moisture of the recording medium 1 is evaporated by passing the recording medium 1 under the drying unit 241. In addition, the drying unit 240 is provided with a recording medium reversing unit 250 including a recording medium reversing mechanism 251. At the time of double-sided printing, the recording medium 1 is reversed and the reversing conveyance unit 252 again moves toward the image forming unit 210. However, before reaching the drum 10, the inclination of the recording medium 1 is corrected by a registration roller 253 provided inside the image forming unit 210. The recording medium 1 that has been dried by the drying unit 240 is conveyed to the paper discharge unit 290 and stacked with the recording medium 1 aligned.

  Each liquid discharge head module (head array) 28 included in the liquid discharge unit 8 in the liquid discharge apparatus 200 is configured as shown in FIG. 2, for example. FIG. 2 is a side view showing the configuration of the liquid discharge unit 8.

  The liquid discharge head module 28 mainly includes a drive control unit 17, a liquid discharge head (recording head) 15, and a cable unit 16.

  The drive control unit 17 includes a drive control board 32, a drive control unit 26, a drive waveform generation unit 27, and a storage unit 18. The drive control unit 26, the drive waveform generation unit 27, and the storage unit 18 can be configured as elements such as a semiconductor package, and are electrically connected to each other and mounted on the drive control board 32.

  The cable unit 16 is disposed between the drive control board 17 and the liquid discharge head (recording head) 15. The cable unit 16 includes a drive control board connector 19, a cable 26, and a head side connector 20. The cable 26 is attached to the drive control board 17 via the drive control board connector 19 and attached to the liquid ejection head (recording head) 15 via the head side connector 20. Thus, communication of analog signals and digital signals between the cable unit 16 drive control board 17 and the head board 22 mounted on the liquid discharge head (recording head) 15 is performed.

  The liquid discharge head (recording head) 15 includes a residual vibration detection module 21, a head substrate 22, a head drive IC substrate 24, an in-head ink tank 23, and a rigid plate 25.

  When the liquid ejection apparatus 200 is a line head type inkjet recording apparatus, the liquid ejection head module (recording head module) 28 is in the depth direction (or the front side) of the paper surface, which is a direction orthogonal to the conveyance direction of the recording medium 1. A line head configuration in which a plurality of liquid discharge heads (recording heads) 15 are arranged corresponding to the width of the recording medium 1 may be employed. Alternatively, the liquid ejection head module (recording head module) 28 moves the liquid ejection head (recording head) 15 in the depth direction (or the front direction) of the paper surface, which is a direction orthogonal to the conveyance direction of the recording medium 1. Furthermore, a serial scanning type configuration in which the recording medium 1 is conveyed in the conveying direction to form an image may be used.

  When the liquid discharge head module 28 has a line head configuration, the liquid discharge unit 8 including a plurality of liquid discharge head modules 28 can be configured as shown in FIG. FIG. 3 is a plan view showing the configuration of the liquid discharge unit 8. In FIG. 3, the direction (sub-scanning direction) along the conveyance direction of the recording medium 1 within the surface (plane or curved surface) along the recording medium 1 is D2, and the direction perpendicular to the direction D2 within the surface is D1. To do. Further, the direction from the upper side to the lower side in FIG. 3 in the direction D1 may be referred to as the + D1 direction, and the direction from the lower side to the upper side in FIG. 3 in the direction D1 may be referred to as the −D1 direction. A direction from the left side to the right side in FIG. 3 in the direction D2 may be referred to as a + D2 direction, and a direction opposite to the direction from the right side to the left side in FIG. 3 in the direction D2 may be referred to as a −D2 direction.

  In the liquid discharge unit 8, a plurality of liquid discharge head modules 28 are arranged along the direction D2. Each liquid discharge head module 28 is arranged such that the direction D1 is the longitudinal direction. The liquid discharge head module 28 has a width in the longitudinal direction corresponding to the width of the recording medium 1 and includes the width of the recording medium 1, and an end on the + D1 side and an end on the −D1 side are different from the recording medium 1. It has a width located slightly outside.

  In each liquid discharge head module 28, a plurality of liquid discharge heads (recording heads) 15 are arranged mainly along the D1 direction. That is, in the liquid discharge head module 28, the plurality of liquid discharge heads 15 are arranged so as to form a plurality of rows HR1 and HR2. The column HR1 is arranged on the + D2 side of the column HR2. In the row HR1, a plurality of liquid ejection heads 15-1 to 15-3 are arranged along the direction D1. In the row HR2, a plurality of liquid ejection heads 15-4 to 15-6 are arranged along the direction D1. Each liquid discharge head 15 is disposed such that the direction D1 is the longitudinal direction.

  In each liquid discharge head module 28, a plurality of liquid discharge heads (recording heads) 15 can be arranged in a staggered manner. The arrangement pitch of the plurality of liquid ejection heads 15 in each row HR1, HR2 is smaller than twice the longitudinal width of each liquid ejection head 15. The center of the pitch of the array in the column HR2 is shifted in the + D1 direction by approximately half the pitch of the array in the column HR1 with respect to the center of the pitch of the array in the column HR1.

  Thereby, in each liquid discharge head module 28, since the plurality of liquid discharge heads 15 are arrayed, a wide printing area can be secured. Further, in the liquid ejection head module 28, the plurality of liquid ejection heads 15 are arranged so that an overlapping region OV is generated along the direction D1 when seen through from the direction D2.

  For example, an overlapping region OV-14 is generated between the liquid discharge head 15-1 and the liquid discharge head 15-4. An overlapping region OV-42 is generated between the liquid discharge head 15-4 and the liquid discharge head 15-2. An overlapping region OV-25 is generated between the liquid discharge head 15-2 and the liquid discharge head 15-5. An overlapping region OV-53 is generated between the liquid ejection head 15-5 and the liquid ejection head 15-3. An overlapping region OV-36 is generated between the liquid discharge head 15-3 and the liquid discharge head 15-6.

  The plurality of liquid discharge head modules 28 may be described as a plurality of liquid discharge head modules 28K to 28P in order to distinguish the colors corresponding to each other. For example, in FIG. 3, a black head array that discharges black ink droplets is shown as a liquid discharge head module 28K, and a cyan head array that discharges cyan ink droplets is shown as a liquid discharge head module 28C. A magenta head array that ejects ink droplets is shown as a liquid ejection head module 28M, and a yellow head array that ejects yellow ink droplets is shown as a liquid ejection head module 28Y.

  When the liquid ejection apparatus 200 is a serial scanning type inkjet recording apparatus, the conveyance direction of the recording medium 1 in FIG. 3 is changed to a direction along D1, and the width of each liquid ejection head module 28 in the direction D2 is changed to the recording medium. By making the width smaller than 1, the above description can be similarly applied.

  Each liquid discharge head (recording head) 15 is configured as shown in FIG. 4, for example. FIG. 4 is an enlarged bottom view showing the configuration of the liquid discharge head 15.

  In each liquid discharge head 15, a plurality of nozzles 30 are arranged mainly along the D1 direction. That is, in the liquid discharge head 15, the plurality of nozzles 30 are arranged so as to form a plurality of rows NR1 and NR2. The column HR1 is arranged on the + D2 side of the column HR2. In the row NR1, a plurality of nozzles 30-1 to 30-k are arranged along the direction D1. In the row NR2, a plurality of nozzles 30- (k + 1) to 30-2k are arranged along the D1 direction.

  In each liquid discharge head 15, a plurality of nozzles 30 can be arranged in a staggered manner. The arrangement pitch of the plurality of nozzles 30 in each row NR1 and NR2 can be approximately twice the width of each nozzle 30 in the direction D1. The center of the pitch of the array in the column NR2 is shifted in the + D1 direction by approximately half the pitch of the array in the column NR1 with respect to the center of the pitch of the array in the column NR1.

  Thereby, in each liquid discharge head 15, since the plurality of nozzles 30 are arrayed, a wide printing area can be secured. Further, each liquid discharge head 15 can cope with high-resolution image formation by arranging a plurality of nozzles 30 in a staggered manner.

  Each liquid discharge head (recording head) 15 is configured as shown in FIG. 5, for example. FIG. 5 is an exploded perspective view showing the configuration of each liquid discharge head (recording head) 15.

  The liquid discharge head (recording head) 15 includes a nozzle plate 31, a pressure chamber plate 33, a restrictor plate 35, a diaphragm plate 38, a rigid plate 25, and a piezo element group 46.

  A nozzle plate 31 in which a large number of nozzles 30 are arranged in a staggered manner, a pressure chamber plate 33 that forms a pressure chamber 32 corresponding to each nozzle 30, a common ink flow path 39, and individual pressure chambers 32 communicate with each other. Then, the restrictor plate 35 forming the restrictor 34 for controlling the ink flow rate to the individual pressure chamber 32, the diaphragm 36, and the diaphragm plate 38 provided with the filter 37 are sequentially stacked and positioned and joined. Thus, a flow path plate is configured.

  This flow path plate is joined to the rigid plate 25 so that the filter 37 faces the opening of the common ink flow path 39. The upper opening end of the ink introduction pipe 41 is connected to the common ink flow path 39 of the rigid plate 25, and the lower opening end of the ink introduction pipe 41 is connected to an ink tank (not shown) filled with ink. The

  A piezo element driving IC 44 is mounted on the piezo element support substrate 43, and a piezo element group 46 configured by arranging a large number of piezo elements 42 is inserted from the opening 40 provided in the rigid plate 25. The liquid discharge head (recording head) 15 is configured by adhering and fixing the free end of the piezo element 42 to the vibration plate 36.

  Note that FIG. 5 illustrates the nozzle 30, the pressure chamber 32, the restrictor 34, and the like by reducing the factors for the sake of simplicity.

  Next, the flushing process by the liquid discharge head module 28 will be described. For example, when a flushing process for performing a labyrinth operation is performed on the entire liquid absorber (ink absorber) 12a in a non-image forming region (region between papers), the liquid (ink) applied to the liquid absorber 12a The landing is as shown in FIG. FIG. 6 is a plan view showing an image of landing on the liquid absorber when the flushing process is performed without replacing the idle ejection operation.

  As shown in FIG. 6, when a plurality of liquid discharge heads (recording heads) 15 are arranged in a staggered manner in the liquid discharge head module 28, the liquid absorbers (ink absorbers) are equally distributed from all the liquid discharge heads 15. When the labyrinth operation is performed on 12a, the landing amount of the region RG1 corresponding to the overlapping region OV tends to increase compared to the landing amount of the other region RG2. That is, in the liquid absorber (ink absorber) 12a, the liquid deposition amount (ink deposition amount) in the region R1 is likely to increase compared to the liquid deposition amount (ink deposition amount) in the other region RG2. Thereby, when the absorption amount of the region RG1 in the liquid absorber 12a reaches a certain amount, the absorption amount of the region RG2 in the liquid absorber 12a does not reach the certain amount, but the liquid absorber 12a. Will be replaced. Thereby, the replacement frequency of the liquid absorber 12a is likely to increase, and the running cost of the liquid absorber 12a may increase.

  When attention is paid to the two liquid discharge heads 15-1 and 15-4 forming the overlapping region OV-14, as shown in FIG. 7, some of the nozzles 30 are used for image formation in the overlapping region OV-14. The remaining nozzles 30 are not used for image formation. FIG. 7 is a plan view showing an overlapping region OV between the plurality of liquid ejection heads 15. In FIG. 7, the nozzles 30 used for image formation are indicated by black circles, and the nozzles 30 not used for image formation are indicated by white circles.

  When the overlapping region OV-14 is divided into the partial region PR1 and the partial region PR2, in the liquid ejection head 15-1, nozzles 30- (k-7) to 30- (k-4), 30 corresponding to the partial region PR1 are used. -(2k-8) to 30- (2k-4) are used for image formation, and nozzles 30- (k-3) to 30-k, 30- (2k-3) to 30- corresponding to the partial region PR2. 2k is not used for image formation.

  Conversely, in the liquid ejection head 15-4, the nozzles 30-1 to 30-4 and 30- (k + 1) to 30- (k + 4) corresponding to the partial region PR1 are not used for image formation and correspond to the partial region PR2. Nozzles 30-5 to 30-9 and 30- (k + 5) to 30- (k + 8) are used for image formation.

  However, when a nozzle failure occurs in the nozzle 30 used for image formation in the overlap region OV-14, the nozzle 30 of the other liquid discharge head 15 that overlaps may be supplemented. In order to perform the complement, it is desirable that the nozzles 30 not used for image formation are also maintained.

  If the usage rate of the nozzles 30 is uneven in the same liquid discharge head 15, the life of the liquid discharge head 15 is reduced. Therefore, the life of the liquid discharge head 15 can be extended by discharging the nozzle 30 that is not used for image formation to a certain level or more.

  For example, as shown in FIG. 8, the life of the liquid discharge head 15 can be extended by replacing the idle discharge operation. FIG. 8 is a plan view showing an image of landing on the liquid absorber 12a when the flushing process is performed by replacing the idle ejection operation. That is, the idle discharge operation of the nozzles 30 that are not used for image formation as shown in FIG. 7 is replaced with a star flushing operation instead of a labyrinth operation.

  For example, when the star flushing operation is performed on the region RG11 corresponding to the overlapping region OV on the recording medium 1 in the image forming region, as shown in the lower diagram of FIG. The liquid droplets) land in a form that is scattered in a star shape. Thereby, in the recording medium 1, the difference in the landing amount of the droplets in the region RG11 and the region RG12 can be easily suppressed.

  On the other hand, in the non-image forming area, the nozzle 30- (k−) used for image formation in the liquid discharge head 15-1 with respect to the area RG1 corresponding to the overlapping area OV on the liquid absorber (ink absorber) 12a. 7) to 30- (k-4), 30- (2k-8) to 30- (2k-4) perform a lainwashing operation, and nozzles 30- (k-3) to 30 which are not used for image formation A star flushing operation is performed from -k, 30- (2k-3) to 30-2k. Further, a star flushing operation is performed on the region RG1 from the nozzles 30-1 to 30-4 and 30- (k + 1) to 30- (k + 4) that are not used for image formation in the liquid ejection head 15-4. From the nozzles 30-5 to 30-9 and 30- (k + 5) to 30- (k + 8) used for image formation, a lainwashing operation is performed. Thereby, in the liquid absorber 12a, it is possible to easily suppress the difference in the landing amount of the droplets in the region RG1 and the region RG2. That is, as shown in FIG. 8, in the liquid absorber 12a, the amount of droplets absorbed can be easily equalized in the region RG1 and the region RG2.

  Such replacement control of the idle ejection operation can be implemented in, for example, a controller (CTL) 50 as shown in FIG. FIG. 9 is a block diagram illustrating a configuration relating to control of the liquid ejection apparatus 200.

  In the liquid ejection apparatus 200, for example, the CTL 50 separately owns image data and star flushing data. At this time, the data for star flushing includes information indicating which nozzles hit how many star flushes in the page.

  The CTL 50 refers to the image data and searches for a timing nozzle that does not have any problem even if the star flushing operation is applied. Then, based on the star flushing data, the star flushing operation is performed at a timing within the image where there is no problem in applying the flushing operation. In the star flushing operation, a dedicated waveform for discharging the star flushing may be prepared, or a waveform for the image forming area may be used.

  The CTL 50 illustrated in FIG. 9 includes a storage unit 51 and a control unit 52. The storage unit 51 can be realized as a memory such as a ROM or a RAM, and holds information on nozzles 30 used for image formation and information on nozzles 30 not used. Based on the information stored in the storage unit 51, the control unit 52 instructs each of the plurality of drive control boards 17-1 to 17-6 to perform nozzle replacement for the idle ejection operation as shown in FIG. In other words, the control unit 52 performs the labyrinsing operation performed for maintenance on the non-image forming region corresponding to the liquid absorber by some of the two or more nozzles included in the overlapping region OV in the plurality of liquid ejection heads 15. Is replaced with the star flushing operation performed for maintenance in the image forming area corresponding to the recording medium 1, and the flushing process is performed on the non-image forming area by the plurality of heads 15.

  Note that the CTL 50 may be configured to have a control unit 52 that can change whether or not replacement is performed by an external signal (not shown). For example, the CTL 50 may change the presence / absence of replacement according to user access, feedback of scan results of the recording medium (output paper medium) 1, and the like.

  Further, the drive control board 17 includes a drive waveform generation unit 54 and a control unit 53. The drive waveform generator 54 generates waveforms before and after replacement. Based on information from the control unit 52, the control unit 53 instructs the liquid ejection head (recording head) 15 on the nozzle 30 to be replaced and its timing.

  The liquid discharge head (recording head) 15 includes a head substrate 22, a head drive IC substrate 24, and a plurality of piezoelectric elements 31a to 31x. The head substrate 22 has a control unit 55. The head drive IC substrate 24 has a piezoelectric element drive IC 56. The control unit 55 controls the piezoelectric element driving IC 56 based on information from the control unit 53. The piezoelectric element drive IC 56 drives the piezoelectric element 31 using the drive waveform from the drive waveform generation unit 54 in accordance with the control from the control unit 55.

  The function / role assignment of each control unit 52, 53, 55 is merely an example, and the assignment may be changed. Further, the internal configuration of the liquid discharge heads 15-2 to 15-6 is the same as that of the liquid discharge head 15-1, and in FIG. The illustration of the configuration is omitted.

  Further, for example, the liquid ejection apparatus 200 can be considered to functionally include the control unit 300 illustrated in FIG. FIG. 10 is a block diagram illustrating a functional configuration of the control unit 300. The control unit 300 includes an operation replacement unit 301 and a flushing control unit 302. The operation replacement unit 301 is used for maintenance in a non-image forming region corresponding to the liquid absorber 12a by some of the two or more nozzles 30 included in the overlapping region OV in the plurality of liquid ejection heads 15. The first idle ejection operation (Lain flushing operation) is replaced with a second idle ejection operation (star flushing operation) performed for maintenance on the image forming area corresponding to the recording medium 1. The flushing control unit 302 performs a flushing process on the non-image forming region by the plurality of liquid ejection heads 15 in a state where the replacement by the operation replacement unit 301 is performed.

  A more specific example of the replacement of the idle ejection operation by the CTL 50 will be described with reference to Table 1. Table 1 is a table showing a control example of replacement of the idle ejection operation.

  Here, the replacement methods (1) to (3) are shown as examples of the replacement method of the idle ejection operation of the nozzles 30 that are not used for image formation shown in FIG. First, when the replacement is not performed, the labyrinth discharge amount is set to Xpl, and the star flushing discharge amount is set to Ypl.

  In the replacement (1), all the Xpls that the nozzles 30 that are not used for image formation are scheduled to be ejected in the labyrinth operation are replaced with the star flushing operation. Although this method is very simple, there is a case where the star flushing amount is simply increased and the image is affected.

  In the replacement (2), only a part of Xpl that was scheduled to be ejected in the raw infrasing operation is added to the star flushing operation. For example, there are two policies for the amount of star flushing. The first is to suppress the replacement of the range that does not affect the image. The second is the amount of star flushing that can maintain the nozzle state to the extent that it can be restored by idle ejection even if the labyrinth operation is lost. It becomes a way. In either case, an appropriate replacement amount (for example, the optimum value of x1) needs to be determined based on prior evaluation and head manufacturing tolerances in the process. In this manner, the amount of ink consumed can be reduced because the idle discharge amount can be reduced compared to the replacement (1).

  The replacement (3) is a method of adjusting the discharge amount of the lainishing operation to an appropriate amount that does not affect the replacement cycle of the liquid absorber (ink absorber). In this case, x2 and x3 in the table may be the same or different discharge amounts. Even in the case of replacement (3), it is necessary to evaluate in advance the ejection amount (for example, the optimum value of x2 and the optimum value of x3) that does not affect the replacement cycle of the liquid absorber (ink absorber). Become. In this manner, it is possible to reduce the influence of replacing the labyrinth operation with the star flushing operation as compared with the replacement (2). Specifically, the nozzle state immediately before the printing area can be stabilized.

  A control example in which the replacement of the idle ejection operation is performed according to the operator setting will be described with reference to Table 2. Table 2 is a table showing an example of control in accordance with the setting example of the operator for replacement of the idle ejection operation.

  Here, an example in which the replacement amount of the idle ejection operation of the nozzle 30 that is not used for image formation in FIG. 7 is controlled according to the setting of the operator is shown. As shown in Table 2, some settings are held as a system, and replacement according to the settings is performed.

  Table 2 shows an example of setting (4) and setting (5) only. However, it is possible to have any number of settings, and the operator can select the setting from the test chart output result. Good. Moreover, you may have setting (1) -setting (3) for every replacement pattern (1)-(3) like Table 1. FIG.

  An example of the operational flow is shown. First, consider the case where the operator selects setting (5) in consideration of the extension of the life of the liquid absorber (ink absorber). As a result of checking the test chart at that time, if the image quality does not satisfy the operator's request (image contamination due to increased star flushing, etc.), the setting is set to (4) and the test chart is flowed.

  If the result satisfies the operator's request, the print job may be started with setting (4) selected.

  As described above, in the embodiment, in the liquid ejection device 200, the idle ejection operation by some of the two or more nozzles included in the region where the liquid landing amount in the liquid absorber 12a is large is the idle ejection with a large ejection amount. The flushing process is performed by replacing the operation (for example, the labyrinth operation) with the idle ejection operation (for example, the star flushing operation) with a small discharge amount. Thereby, the dispersion | variation in the liquid landing amount in the liquid absorber 12a can be suppressed, and the cost of the liquid absorber 12a can be reduced easily. That is, the replacement frequency of the liquid absorber 12a can be reduced, and the cost associated with the replacement of the liquid absorber 12a can be reduced. Or since the dispersion | variation in the amount of liquid landing can be suppressed, maintaining the liquid absorber 12a with a simple structure, the increase in the manufacturing cost by the structure complexity of the liquid absorber 12a can be avoided.

  The “liquid ejection head” may be a head other than the recording head for an ink jet recording apparatus as long as it is a functional component that ejects and ejects liquid from a nozzle. The liquid to be ejected is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, and the viscosity is 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. It is preferable. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, etc., suspensions, emulsions, etc. These include, for example, inkjet inks, surface treatment liquids, components of electronic elements and light emitting elements, and formation of electronic circuit resist patterns It can be used in applications such as a liquid for use, a material liquid for three-dimensional modeling. As energy generation sources for discharging liquid, piezoelectric actuators (laminated piezoelectric elements and thin film piezoelectric elements), thermal actuators using electrothermal transducers such as heating resistors, electrostatic actuators consisting of a diaphragm and counter electrode are used. To be included.

  In this specification, image formation, recording, printing, printing, printing, modeling, etc. are all synonymous.

  The “liquid ejection unit” is an assembly of other functional parts and mechanisms integrated with the liquid ejection head, and is an assembly of parts related to the function of ejecting liquid. For example, the “liquid discharge unit” includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

  Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated. Also, there are some in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid discharge head of these liquid discharge units.

  In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  In addition, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably on a guide member that constitutes a part of the scanning movement mechanism. In some cases, a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated.

  Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated .

  In addition, there is a liquid discharge unit in which a tube is connected to a liquid discharge head to which a head tank or a flow path component is attached, and the liquid discharge head and a supply mechanism are integrated. The liquid from the liquid storage source is supplied to the liquid discharge head via this tube.

  The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

  The “liquid discharge device” is a device that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  The “liquid ejecting apparatus” can include means for feeding, transporting, and ejecting a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as a “liquid ejecting apparatus”, an image forming apparatus that is an apparatus that ejects ink to form an image on paper, a powder in which powder is formed in a layer to form a three-dimensional structure (three-dimensional structure) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid to a body layer.

  Further, the “liquid ejecting apparatus” is not limited to the one in which a significant image such as a character or a figure is visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “applicable liquid” means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes everything that the liquid adheres to.

  The material of the above-mentioned “material to which liquid can adhere” is not limited as long as liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics can be adhered even temporarily.

  The “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, and the viscosity is 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. Preferably there is. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, etc., suspensions, emulsions, etc. These include, for example, inkjet inks, surface treatment liquids, components of electronic elements and light emitting elements, and formation of electronic circuit resist patterns It can be used in applications such as a liquid for use, a material liquid for three-dimensional modeling.

  In addition, the “liquid ejecting apparatus” includes an apparatus in which the liquid ejecting head and the apparatus to which the liquid can be attached move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  In addition, as a “liquid ejecting device”, a processing liquid coating apparatus that ejects a processing liquid onto a sheet in order to apply the processing liquid onto the surface of the sheet for the purpose of modifying the surface of the sheet, and a raw material solution There is an injection granulating apparatus for granulating raw material fine particles by spraying a composition liquid dispersed therein through a nozzle.

15, 15-1 to 15-6 Liquid discharge head 52, 53, 55 Control unit 200 Liquid discharge device

Japanese Patent No. 5045351

Claims (10)

Each of the plurality of nozzles arranged along the first direction has an overlapping area with an adjacent head along the first direction when viewed from a second direction orthogonal to the first direction. A plurality of heads arranged to occur;
Corresponding to the recording medium, the first idle ejection operation performed for maintenance in the non-image forming area corresponding to the liquid absorber by some of the two or more nozzles included in the overlapping area in the plurality of heads A controller that replaces the image forming area with the second idle ejection operation performed for maintenance;
A liquid ejecting apparatus comprising: The control unit suppresses a difference in ejection amount due to an idle ejection operation between an area corresponding to the some nozzles in the non-image forming area and an area corresponding to the remaining nozzles of the two or more nozzles. The liquid ejecting apparatus according to claim 1, wherein the first idle ejection operation by the some nozzles is replaced with the second idle ejection operation. The control unit replaces the first idle ejection operation by the some nozzles with the second idle ejection operation so that the number of ejections of the some nozzles is suppressed. The liquid discharge apparatus according to 1. 4. The control unit according to claim 1, wherein the control unit replaces the first idle ejection operation by a nozzle that is not used for image formation among the two or more nozzles with the second idle ejection operation. 5. The liquid discharge apparatus according to item 1. The control unit replaces the first idle ejection operation with a nozzle that is used for image formation among the two or more nozzles and has an ejection amount equal to or less than a predetermined amount, with the second idle ejection operation. The liquid discharge apparatus according to claim 1. The control unit replaces the first idle ejection operation by the partial nozzle that does not affect the image among the two or more nozzles with the second idle ejection operation. 6. The liquid ejection device according to any one of 5 above. The control unit replaces the first idle ejection operation by the partial nozzle according to the setting by an operator among the two or more nozzles with the second idle ejection operation. The liquid ejection device according to any one of 6. A reading unit capable of reading the recording medium after image formation;
The control unit performs the first idle ejection operation by the second idle ejection operation by the some nozzles that do not affect the image among the two or more nozzles based on the reading result by the reading unit. The liquid ejecting apparatus according to claim 6, wherein the liquid ejecting apparatus is replaced. The control unit replaces the first idle ejection operation with the second idle ejection operation by the some nozzles corresponding to pixels that are used for image formation and do not require image quality among the two or more nozzles. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. Each of the plurality of nozzles arranged along the first direction has an overlapping region with an adjacent head along the first direction when seen through a second direction orthogonal to the first direction. A first idle ejection operation performed for maintenance in a non-image forming area corresponding to a liquid absorber by some of the two or more nozzles included in the overlapping area in a plurality of heads arranged to occur. A step of replacing the image forming region corresponding to the recording medium with a second idle ejection operation performed for maintenance, and a step of performing a flushing process on the non-image forming region with the plurality of heads in a state of replacement.
A liquid discharge method comprising:

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