JP5911779B2 - Image recording apparatus and control method thereof - Google Patents

Description

  The present invention relates to an image recording apparatus and a control method thereof, and more particularly to a technique for performing maintenance of a liquid discharge head.

  In the ink jet recording apparatus, if the nozzle surface of the ink jet head (surface on which the nozzles are formed) is dirty, defective ejection occurs. For this reason, it is necessary to clean (maintenance) the nozzle surface.

  However, since the maintenance requires a predetermined time, there is a problem that if the maintenance is frequently performed, the time until the printing is finished increases.

  Further, as a method for cleaning the nozzle surface, a method is known in which the nozzle surface is wiped with a web impregnated with a cleaning liquid. If maintenance using such a cleaning liquid and web is performed more than necessary, there is a problem that costs increase.

  Further, the maintenance may damage the liquid repellent film formed on the nozzle surface.

  Therefore, it is required to perform the maintenance to the minimum necessary.

  To deal with such a problem, Patent Document 1 discloses a technique for starting a maintenance operation at a timing when a print setting screen for setting print conditions for print data is activated and performing a maintenance operation according to the print conditions for print data. Has been. According to this technique, more appropriate maintenance can be performed according to printing conditions.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for postponing maintenance when the print condition received together with the print information corresponds to a maintenance postponement condition, and performing maintenance when the print condition does not correspond. According to this technique, if the maintenance postponement condition is satisfied, the printing process is continued without interrupting the printing process, so that unnecessary maintenance is not performed.

JP 2011-056754 A JP 2000-238285 A

  In Patent Documents 1 and 2, although maintenance is performed according to printing conditions, the environment in which the inkjet head is placed is not considered, and there is a drawback that maintenance cannot be performed appropriately.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an image recording apparatus and a control method therefor that perform appropriate maintenance in consideration of the environment in which the head is placed.

In order to achieve the above object, one aspect of an image recording apparatus includes: a liquid discharge head having a nozzle for discharging a liquid; and a liquid discharge head and a recording medium, while discharging the liquid from the nozzle. A recording unit that records an image on a recording medium, a moisturizing unit that moisturizes the nozzles of the liquid discharge head, and a recording position that is recorded on the recording medium by the recording unit, and a standby position that is different from the recording position. A moving unit that moves the liquid ejection head to a standby position that is a moisturizing position for moisturizing the nozzle; a first mode that moves the liquid ejection head to the standby position when switching an image to be recorded by the recording unit; and a recording unit. Selecting means for selecting any one of the second mode in which the liquid ejection head is maintained at the recording position when the image to be recorded is switched; Maintenance means for performing maintenance of the liquid discharge head, counting means for counting the number of recording sheets by the recording means from the time when maintenance by the maintenance means is performed, registration means for registering images to be recorded by the recording means, and registered images When the first mode is selected when all the recordings are completed, maintenance by the maintenance means is performed when the number of recorded sheets exceeds the first number, and when the second mode is selected. Control means for performing maintenance by the maintenance means when the number of recording sheets exceeds a second number smaller than the first number.
In order to achieve the above object, one aspect of an image recording apparatus includes: a liquid discharge head having a nozzle for discharging a liquid; and a liquid discharge head and a recording medium, while discharging the liquid from the nozzle. A recording unit that records an image on a recording medium, a moisturizing unit that moisturizes the nozzles of the liquid discharge head, and a recording position that is recorded on the recording medium by the recording unit, and a standby position that is different from the recording position. A moving unit that moves the liquid ejection head to a standby position that is a moisturizing position for moisturizing the nozzle; a first mode that moves the liquid ejection head to the standby position when switching an image to be recorded by the recording unit; and a recording unit. Selecting means for selecting any one of the second mode in which the liquid ejection head is maintained at the recording position when the image to be recorded is switched; Maintenance means for performing maintenance of the liquid discharge head, timekeeping means for measuring the holding time for which the liquid discharge head has been held at the recording position since the maintenance by the maintenance means, and registration for registering an image to be recorded by the recording means And when the first mode is selected when all of the registered images have been recorded, if the holding time exceeds the first time, the maintenance means performs maintenance, and the second mode And control means for performing maintenance by the maintenance means when the holding time exceeds a second time shorter than the first time when the mode is selected.
In order to achieve the above object, one aspect of an image recording apparatus includes: a liquid discharge head having a nozzle for discharging a liquid; and a liquid discharge head and a recording medium, while discharging the liquid from the nozzle. Recording means for recording an image on a recording medium, recording means for recording on the recording medium by the recording means, moving means for moving the liquid ejection head to a standby position different from the recording position, and an image to be recorded by the recording means A selector for selecting one of a first mode for moving the liquid ejection head to the standby position and a second mode for maintaining the liquid ejection head at the recording position when switching; and the liquid ejection head Maintenance means for performing maintenance of the recording medium, and counting means for counting the number of recordings by the recording means from the time when maintenance by the maintenance means is performed A registration unit for registering an image to be recorded by the recording unit; and when the first mode is selected when recording of all the registered images has been completed, if the number of recordings exceeds the first number, the maintenance unit When the second mode is selected when the maintenance is performed, there is provided control means for performing maintenance by the maintenance means when the number of recorded sheets exceeds the second number smaller than the first number.

  According to this aspect, the number of sheets recorded by the recording unit from the time point when the maintenance by the maintenance unit is performed is counted, and the recording is performed when the first mode is selected when all the recorded images have been recorded. When the number exceeds the first number, maintenance is performed by the maintenance unit. When the second mode is selected, when the number of recordings exceeds the second number less than the first number, maintenance by the maintenance unit is performed. Therefore, maintenance can be appropriately performed according to the environment where the liquid discharge head is placed. Therefore, maintenance is not performed more than necessary, and maintenance time and cost can be suppressed.

  In order to achieve the above object, one aspect of an image recording apparatus includes: a liquid discharge head having a nozzle for discharging a liquid; and a liquid discharge head and a recording medium, while discharging the liquid from the nozzle. Recording means for recording an image on a recording medium, recording means for recording on the recording medium by the recording means, moving means for moving the liquid ejection head to a standby position different from the recording position, and an image to be recorded by the recording means A selector for selecting one of a first mode for moving the liquid ejection head to the standby position and a second mode for maintaining the liquid ejection head at the recording position when switching; and the liquid ejection head Maintenance means for performing maintenance of the liquid and when the liquid discharge head is held at the recording position from the time when maintenance is performed by the maintenance means Timing means for timing the image, registration means for registering an image to be recorded by the recording means, and when the first mode is selected when recording of all the registered images is completed, the holding time is the first When the time exceeds, the maintenance means performs maintenance. When the second mode is selected, the maintenance means performs maintenance when the holding time exceeds the second time shorter than the first time. Control means to be implemented.

  According to this aspect, the first mode is selected when the recording time of the liquid discharge head from the time point when the maintenance by the maintenance means is held and the recording of all registered images is completed. If the holding time exceeds the first time, maintenance by the maintenance means is performed. If the second mode is selected, the second holding time is shorter than the first time. Since the maintenance by the maintenance means is performed when the time exceeds the time, maintenance can be appropriately performed according to the environment where the liquid discharge head is placed. Therefore, maintenance is not performed more than necessary, and maintenance time and cost can be suppressed.

  It is preferable that a moisturizing unit that moisturizes the nozzles of the liquid discharge head is provided, and the standby position is a moisturizing position that moisturizes the nozzles by the moisturizing unit. Thereby, when the image to be recorded is switched by the recording means in the first mode, the nozzle of the liquid ejection head can be moisturized, so that the nozzle can be prevented from drying.

  The maintenance unit is preferably arranged between the recording position and the standby position. Thereby, maintenance can be performed without increasing the amount of movement of the liquid ejection head.

  The maintenance means preferably includes wiping means for wiping the liquid discharge surface of the liquid discharge head. Thereby, the maintenance of the liquid discharge head can be performed appropriately. In addition to the wiping of the liquid discharge surface, the maintenance means may be purge, nozzle suction, or the like.

  The liquid may contain latex. As used herein, latex is a dispersion of a fine polymer component insoluble in water in an aqueous medium. If latex is contained, the liquid is easily solidified. However, according to this aspect, even when a liquid containing latex is used, maintenance of the liquid discharge head can be appropriately performed.

  The liquid discharge head is provided with a liquid supply port for supplying liquid to the nozzle, a liquid discharge port for discharging liquid that is not discharged from the nozzle, a liquid tank that stores liquid, and a liquid supply from the liquid tank. In addition to supplying liquid to the mouth, an ink flow generating means for collecting the liquid from the liquid discharge port to the liquid tank may be provided. Even when the system for circulating the liquid is provided, the liquid may be dried on the nozzle surface. According to this aspect, even when such a liquid circulation path is provided, the liquid discharge head can be appropriately maintained.

  A processing liquid application unit that applies the processing liquid to the recording medium before the image is recorded by the recording unit and dries the applied processing liquid may be disposed close to the recording position. As described above, even when the processing liquid is dried at a position close to the recording position, according to this aspect, the liquid discharge head can be appropriately maintained.

  A drying unit that dries the liquid discharged to the recording medium by the recording unit may be disposed in the vicinity of the recording position. As described above, even when the liquid ejected at a position close to the recording position is dried, according to this aspect, the liquid ejection head can be appropriately maintained.

  In order to achieve the above object, one aspect of a method for controlling an image recording apparatus includes: a liquid discharge head having a nozzle for discharging a liquid; and a liquid discharge head and a recording medium while moving the liquid from the nozzle while relatively moving the liquid discharge head and the recording medium. Recording means for recording an image on a recording medium by discharging, recording means for recording on the recording medium by the recording means, moving means for moving the liquid discharge head to a standby position different from the recording position, and recording by the recording means Selecting means for selecting one of a first mode for moving the liquid ejection head to the standby position and a second mode for maintaining the liquid ejection head at the recording position when switching the image to be performed; A maintenance unit for performing maintenance on the liquid discharge head, and a method for controlling the image recording apparatus, wherein the maintenance unit performs maintenance. A counting step for counting the number of recordings by the recording means, a registration step for registering an image to be recorded by the recording means, and when the first mode is selected when recording of all the registered images is completed When the number of recorded sheets exceeds the first number, the maintenance means performs maintenance. When the second mode is selected, the number of recorded sheets exceeds the second number smaller than the first number, and the maintenance means. And a control process for carrying out the maintenance.

  According to this aspect, the number of sheets recorded by the recording unit from the time point when the maintenance by the maintenance unit is performed is counted, and the recording is performed when the first mode is selected when all the recorded images have been recorded. When the number exceeds the first number, maintenance is performed by the maintenance unit. When the second mode is selected, when the number of recordings exceeds the second number less than the first number, maintenance by the maintenance unit is performed. Therefore, maintenance can be appropriately performed according to the environment where the liquid discharge head is placed. Therefore, maintenance is not performed more than necessary, and maintenance time and cost can be suppressed.

  In order to achieve the above object, one aspect of a method for controlling an image recording apparatus includes: a liquid discharge head having a nozzle for discharging a liquid; and a liquid discharge head and a recording medium while moving the liquid from the nozzle while relatively moving the liquid discharge head and the recording medium. Recording means for recording an image on a recording medium by discharging, recording means for recording on the recording medium by the recording means, moving means for moving the liquid discharge head to a standby position different from the recording position, and recording by the recording means Selecting means for selecting one of a first mode for moving the liquid ejection head to the standby position and a second mode for maintaining the liquid ejection head at the recording position when switching the image to be performed; A maintenance unit for performing maintenance on the liquid discharge head, and a method for controlling the image recording apparatus, wherein the maintenance unit performs maintenance. A time measuring process for measuring the holding time during which the liquid ejection head is held at the recording position, a registration process for registering an image to be recorded by the recording means, and a first mode when recording of all the registered images is completed Is selected, the maintenance means performs maintenance when the holding time exceeds the first time. When the second mode is selected, the second holding time is shorter than the first time. And a control step for carrying out maintenance by the maintenance means when the time is exceeded.

  According to this aspect, the first mode is selected when the recording time of the liquid discharge head from the time point when the maintenance by the maintenance means is held and the recording of all registered images is completed. If the holding time exceeds the first time, maintenance by the maintenance means is performed. If the second mode is selected, the second holding time is shorter than the first time. Since the maintenance by the maintenance means is performed when the time exceeds the time, maintenance can be appropriately performed according to the environment where the liquid discharge head is placed. Therefore, maintenance is not performed more than necessary, and maintenance time and cost can be suppressed.

  According to the present invention, since maintenance is appropriately performed according to the environment in which the head is placed, it is possible to perform maintenance of the head that achieves both cost and image quality.

Front view showing the configuration of the main part of the inkjet recording apparatus A plan view showing a configuration of a main part of an ink jet recording apparatus Side view showing the configuration of the main part of the inkjet recording apparatus Plane perspective view showing a structural example of the entire head module and inkjet head Sectional view showing the three-dimensional configuration of the ink chamber unit Flow path configuration diagram showing the flow path structure inside the head module Schematic diagram showing the schematic configuration of the wiping unit Block diagram showing electrical configuration of inkjet recording apparatus Flow chart showing operation of ink jet recording apparatus It is a figure which shows the structural example of an inkjet recording device. Drawing top view The figure which shows the conditions of evaluation about the relationship between maintenance frequency and landing position deviation The figure which shows the maximum value of σ of the absolute value of the landing position deviation of each inkjet head Flow chart showing operation of ink jet recording apparatus

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Apparatus configuration of inkjet recording apparatus>
1 to 3 are a front view, a plan view, and a side view showing a configuration of a main part of the ink jet recording apparatus of the present embodiment.

  As shown in FIG. 1, the inkjet recording apparatus 10 is a single-pass line printer, and mainly includes a sheet conveying mechanism 20 that conveys a sheet (sheet) P that is a recording medium, and a sheet conveying mechanism 20. A head unit 30 that discharges ink droplets (an example of liquid) of cyan (C), magenta (M), yellow (Y), and black (K) each containing latex toward the paper P to be conveyed. An example of a liquid discharge head, an example of a recording unit is configured by the paper transport mechanism 20 and the head unit 30), a moisturizing unit 40 (an example of a moisturizing unit) that moisturizes each head mounted on the head unit 30, and a head A nozzle surface cleaning device 80 (an example of maintenance means) that cleans the nozzle surface of each head mounted on the unit 30 is configured.

  The paper transport mechanism 20 is constituted by a belt transport mechanism, and adsorbs the paper P to the traveling belt 22 and transports the paper P horizontally.

  The head unit 30 mainly includes a head 32C that ejects cyan ink droplets, a head 32M that ejects magenta ink droplets, a head 32Y that ejects yellow ink droplets, and a head 32K that ejects black ink droplets. The head support frame 34 to which the heads 32C, 32M, 32Y, and 32K are attached, and a head support frame moving mechanism (not shown) that moves the head support frame 34 are configured.

  The heads (inkjet heads) 32C, 32M, 32Y, and 32K are constituted by line heads corresponding to the maximum paper width of the paper P to be printed. Since the configurations of the heads 32C, 32M, 32Y, and 32K are the same, in the following, they are described as the heads 32 unless otherwise distinguished.

  The head 32 is formed in a rectangular block shape, and a nozzle surface 33 (33C, 33M, 33Y, 33K) is formed at the bottom thereof.

  FIG. 4A is a plan perspective view showing a structural example of the head module 32 ′ constituting the inkjet head, FIG. 4B is a partially enlarged view thereof, and FIG. FIG. 3 is a perspective plan view showing an example of the overall structure of an inkjet head 32 composed of a head module 32 ′.

  5 is a cross-sectional view (a cross-sectional view taken along line 6-6 in FIGS. 4A and 4B) showing the three-dimensional configuration of the ink chamber unit, and FIG. 6 shows the inside of the head module 32 ′. FIG. 6 is a flow channel configuration diagram showing a flow channel structure (a plan perspective view seen from the direction A in FIG. 5).

  In order to increase the dot pitch formed on the recording medium, it is necessary to increase the nozzle pitch in the head 32. As shown in FIGS. 4A and 4B, the head module 32 ′ of this example includes a plurality of ink chambers including nozzles 51 serving as ink droplet ejection holes, pressure chambers 52 corresponding to the nozzles 51, and the like. The unit 53 has a structure in which the unit 53 is arranged in a matrix (two-dimensionally) in a fixed arrangement pattern, and is thereby projected so as to be aligned along the longitudinal direction of the head (main scanning direction orthogonal to the paper transport direction). High density of substantial nozzle interval (projection nozzle pitch) is achieved.

  As shown in FIG. 4C, a long inkjet head 32 having a nozzle row having a length corresponding to the entire width of the recording medium is configured by arranging short head modules 32 'in a staggered manner and connecting them together. To do. Although not shown, a long ink jet head may be configured by arranging short head modules in a line.

  Note that the form in which one or more nozzle rows are configured in a direction substantially orthogonal to the paper conveyance direction over a length corresponding to the entire width of the recording medium is not limited to this example. For example, instead of arranging a plurality of head modules 32 ′, a long inkjet head corresponding to a single head module 32 ′ having the nozzle array structure shown in FIG.

  The pressure chamber 52 provided corresponding to each nozzle 51 has a substantially square planar shape, and the nozzle 51 and the ink inlet 54 are provided at both corners on the diagonal line. Each pressure chamber 52 is communicated with an individual flow path 59 via an ink inlet 54, and each individual flow path 59 is communicated with a common flow path 55. Further, the nozzle flow path 60 communicating with each pressure chamber 52 is communicated with the circulation common flow path 64 via the individual circulation flow path 62. The head module 32 ′ is provided with a supply port 66 (an example of a liquid supply port) and a discharge port 68 (an example of a liquid discharge port). The supply port 66 communicates with the common flow channel 55, and the discharge port 68 circulates. The common flow path 64 is communicated.

  In other words, the supply port 66 and the discharge port 68 of the head module 32 ′ are the common channel 55, the individual channel 59, the ink inlet 54, the pressure chamber 52, the nozzle channel 60, the individual circulation channel 62, and the circulation. It is configured to communicate through an ink flow path (internal flow path) including a common flow path 64. For this reason, a part of the ink supplied from the outside of the head module to the supply port 66 is ejected from each nozzle 51, and the remaining ink is common flow channel 55, individual flow channel 59, nozzle flow channel 60, individual circulation flow. The ink is discharged from the discharge port 68 to the outside of the head module via the path 62 and the circulation common flow path 64 in order (that is, circulating through the ink flow path inside the head module).

  As shown in FIG. 5, a configuration in which the individual circulation flow path 62 is connected to the vicinity of the nozzle 51 of the nozzle flow path 60 is preferable, and the ink circulates in the vicinity of the nozzle 51. Drying) is prevented, and stable ejection becomes possible.

  A piezoelectric element 58 having an individual electrode 57 is joined to a diaphragm 56 that constitutes the top surface of the pressure chamber 52 and also serves as a common electrode. By applying a driving voltage to the individual electrode 57, the piezoelectric element 58 is Deformation causes ink to be ejected from the nozzle 51. When ink is ejected, new ink is supplied from the common channel 55 to the pressure chamber 52 through the individual channel 59 and the ink inlet 54.

  In this example, the piezoelectric element 58 is applied as a means for generating ink ejection force to be ejected from the nozzle 51 provided in the head module 32 ′. However, a heater is provided in the pressure chamber 52, and the pressure of film boiling caused by heating of the heater is increased. It is also possible to apply a thermal method in which ink is ejected using it.

  As shown in FIG. 4B, the ink chamber units 53 having such a structure are arranged in a fixed manner along a row direction along the main scanning direction and an oblique column direction having a constant angle θ that is not orthogonal to the main scanning direction. By arranging a large number of patterns in a lattice pattern, the high-density nozzle head of this example is realized.

  That is, with a structure in which a plurality of ink chamber units 53 are arranged at a constant pitch d along the direction of an angle θ with respect to the main scanning direction, the pitch P of the nozzles projected in the main scanning direction is d × cos θ. Thus, in the main scanning direction, each nozzle 51 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a high-density nozzle configuration in which 2400 nozzle rows are projected per inch (2400 nozzles / inch) so as to be aligned in the main scanning direction.

  In this embodiment, the nozzle arrangement structure is not limited to the illustrated example, and various nozzle arrangement structures such as an arrangement structure having one nozzle row in the sub-scanning direction can be applied.

  Returning to the description of FIGS. 1 to 3, the head support frame 34 includes a head mounting portion (not shown) for mounting the heads 32. Each head 32 is detachably attached to the head attachment portion.

  Each head 32 attached to the head support frame 34 is arranged orthogonal to the transport direction of the paper P. Further, the paper P is arranged in a predetermined order at a constant interval along the conveyance direction of the paper P (in this example, the paper P is arranged in the order of cyan, magenta, yellow, and black).

  The head mounting portion is provided on the head support frame 34 so as to be movable up and down, and is moved up and down by a lifting mechanism (not shown). Each head 32 attached to the head attaching portion is raised and lowered vertically with respect to the transport surface of the paper P by this lifting mechanism.

  The head support frame moving mechanism (an example of a moving unit) slides the head support frame 34 horizontally in a direction perpendicular to the paper P transport direction at a position above the paper transport mechanism 20.

  The head support frame moving mechanism includes, for example, a ceiling frame that is horizontally installed across the paper transport mechanism 20, a guide rail laid on the ceiling frame, a traveling body that slides on the guide rail, and its traveling It is comprised by the drive means (for example, feed screw mechanism etc.) which moves a body along a guide rail. The head support frame 34 is attached to the traveling body and slides horizontally.

  The head support frame 34 is driven by the head support frame moving mechanism, and is provided so as to be movable between a predetermined “image recording position” and a “moisturizing position”.

  The head support frame 34 is disposed above the paper transport mechanism 20 when positioned at the image recording position. As a result, printing can be performed on the paper P transported by the paper transport mechanism 20.

  On the other hand, when it is located at the moisturizing position (an example of the standby position), it is disposed at the installation position of the moisturizing unit 40.

  The moisturizing unit 40 includes a cap 42 (42C, 42M, 42Y, 42K) that covers the nozzle surface 33 of each head 32. When the apparatus is stopped for a long time, the head 32 is moved to the installation position (humidity retention position) of the moisture retention unit 40 and the nozzle surface 33 is covered with the cap 42. Thereby, non-ejection due to drying is prevented.

  The cap 42 includes a pressurization / suction mechanism (not shown) for pressurizing and sucking the inside of the nozzle, and a cleaning liquid supply mechanism (not shown) for supplying a cleaning liquid into the cap 42. A waste liquid tray 44 is disposed below the cap 42. The cleaning liquid supplied to the cap 42 is discarded in the waste liquid tray 44 and recovered from the waste liquid tray 44 to the waste liquid tank 48 through the waste liquid recovery pipe 46.

  The nozzle surface cleaning device 80 is disposed between the paper transport mechanism 20 and the moisturizing unit 40. The nozzle surface cleaning device 80 cleans the nozzle surface 33 by wiping the nozzle surface 33 of the head 32 with the wiping web to which the cleaning liquid is applied when the head support frame 34 moves from the image recording position to the moisturizing position. To do.

<Device configuration of nozzle surface cleaning device>
The nozzle surface cleaning device 80 mainly includes wiping units 100C, 100M, 100Y, and 100K attached to the wiping device main body frame 82, and a wiping device main body lifting mechanism (not shown) that lifts and lowers the wiping device main body frame 82. .

  The wiping units 100C, 100M, 100Y, and 100K (an example of the wiping means) contact the nozzle surface 33 of the head 32 while running the wiping web (101 in FIG. 7) formed in a belt shape, thereby causing the nozzle surface 33 to move. Wipe away. The wiping units 100 </ b> C, 100 </ b> M, 100 </ b> Y, and 100 </ b> K are provided for each head, and are installed on the wiping device main body frame 82 according to the installation interval of the heads 32. In addition, since the structure of each wiping unit 100C, 100M, 100Y, 100K is the same, the structure is demonstrated as the wiping unit 100 here.

  FIG. 7 is a schematic diagram illustrating a schematic configuration of the wiping unit 100. As shown in the figure, the wiping unit 100 is driven to rotate by a sending-side web core 102 that sends out the wiping web 101 before wiping, and a take-up motor (not shown), thereby removing the wiping web 101 that has been wiped off. The winding side web core 103 to be wound up, the wiping web 101 sent out from the sending side web core 102 and rotating in contact with the first guide roll 104 that guides to the cleaning liquid application unit 105, and a predetermined amount on the wiping web 101 A cleaning liquid application unit 105 that applies a cleaning liquid, a second guide roll 106 that rotates in contact with the wiping web 101 delivered from the cleaning liquid application unit 105, and guides the wiping web 101 to the pressing roll 107. And a pressing roll 107 which is brought into contact with 33 at a predetermined pressure.

  The wiping web 101 is formed of a sheet made of knitting or weaving using ultrafine fibers such as polyethylene terephthalate, polyethylene, nylon, and the like, and is formed in a strip shape having a width corresponding to the width of the nozzle surface 33 of the head 32. The The wiping web 101 is provided in a state in which the wiping web 101 is wound around the delivery-side web core 102 in a roll shape and the tip is fixed to the take-up-side web core 103.

  The delivery-side web core 102 is fitted and attached to a delivery shaft (not shown) that is fixed at one end and supported horizontally. The delivery shaft has a double tube structure, and an outer cylinder is rotatably supported around the inner cylinder. A reverse rotation prevention mechanism and a friction mechanism are arranged between the inner cylinder and the outer cylinder, and the outer cylinder is configured to rotate only in one direction (the feeding direction of the wiping web 101) with a certain resistance.

  The winding-side web core 103 is fitted and mounted on a winding shaft (not shown) that is rotatably supported horizontally. A take-up motor is connected to the take-up shaft, and the take-up web core 103 is driven by the take-up motor to rotate in one direction (winding direction of the wiping web 101).

  The take-up shaft has a double structure, and an outer cylinder is rotatably supported around the inner cylinder. A torque limiter is disposed between the inner cylinder and the outer cylinder, and is configured such that the outer cylinder slides with respect to the inner cylinder when a load (torque) exceeding a certain level is applied. Thereby, it can prevent that excessive tension | tensile_strength is applied to the wiping web 101. FIG.

  The first guide roll 104 is rotatably supported by a horizontally installed shaft (not shown) and guides the wiping web 101 delivered from the delivery-side web core 102 toward the cleaning liquid application unit 105.

  The cleaning liquid applying unit 105 sprays the cleaning liquid onto the wiping web 101 from the cleaning liquid nozzle, and applies a fixed amount of the cleaning liquid to the wiping web 101. The method for applying the cleaning liquid to the wiping web 101 is not limited to spraying from the cleaning liquid nozzle. For example, the aspect provided using an anilox roll etc. can be considered.

  The second guide roll 106 is rotatably supported by a horizontally installed shaft (not shown), and guides the wiping web 101 delivered from the cleaning liquid application unit 105 toward the pressing roll 107.

  The pressing roll 107 is horizontally installed with one end of its shaft portion supported rotatably. The pressing roll 107 is composed of a rubber roll corresponding to the width of the wiping web 101, and causes the wiping web 101 to contact the nozzle surface 33 of the head 32 with a predetermined pressure.

<Operation of nozzle surface cleaning device>
Next, the operation of the nozzle surface cleaning device 80 configured as described above will be described.

  The operation of the nozzle surface cleaning device 80 is controlled by a control device (control unit 90 shown in FIG. 8) that controls the entire inkjet recording device 10. The control device wipes and cleans the nozzle surface 33 with the nozzle surface cleaning device 80 in the process of moving the head 32 from the image recording position to the moisturizing position.

  The entire nozzle surface cleaning device 80 is configured to be movable up and down by a wiping device main body lifting mechanism. The nozzle surface cleaning device 80 is located at a predetermined standby position except during cleaning, and is positioned at a predetermined operation position that is a position raised by a predetermined amount from the standby position during cleaning.

  In a state where the nozzle surface cleaning device 80 is located at the operating position, the nozzle surfaces 33 of the heads 32 can be wiped by the wiping units 100. That is, when the head 32 passes through each wiping unit 100, the wiping web 101 wound around the pressure roll 107 can be pressed against the nozzle surface 33.

  The control device controls the conveyance of the wiping web 101 by controlling the driving of the winding motor in accordance with the timing at which each head 32 reaches the wiping unit 100. As a result, the wiping web 101 is unrolled from the sending-side web core 102 and travels, and is taken up by the winding-side web core 103.

  At this time, the feeding shaft of the feeding-side web core 102 is given friction by the friction mechanism, while the winding shaft of the winding-side web core 103 slips when a certain load is applied by the torque limiter. It is possible to run the vehicle with a certain tension applied thereto.

  The control device controls the cleaning liquid application unit 105 simultaneously with the traveling of the wiping web 101 to wet the wiping web 101 with the cleaning liquid. The appropriate amount of wiping web 101 (an amount suitable for wiping the nozzle surface 33) is determined by the absorption capacity of the wiping web 101, the liquid repellency (ink contact angle) of the nozzle surface 33, the physical properties of the ink, and the nozzle diameter. It depends on.

Further, the appropriate amount of cleaning liquid varies depending on the inkjet heads 32C, 32M, 32Y, and 32K. Accordingly, the cleaning liquid may be ejected from the cleaning liquid applying unit 105 according to the amount of the cleaning liquid required.

  Thereby, the wiping web 101 can be made into the state moistened with the appropriate amount of washing | cleaning liquid, and the absorption capacity of the wiping web 101 will be in an optimal state. As a result, it is possible to prevent the cleaning liquid from entering the liquid and sagging when the nozzle surface 33 is wiped.

  The wiping web 101 to which the cleaning liquid is given in this manner is guided to the pressing roll 107 by the second guide roll 106 and is pressed against the nozzle surface 33 in the pressing roll 107 by running by driving of the take-up motor. 33 is wiped and cleaned.

  At this time, the wiping web 101 travels in the direction opposite to the moving direction of the nozzle surface 33 and wipes the nozzle surface 33. Thereby, the nozzle surface 33 can be wiped off efficiently. In addition, the nozzle surface 33 can always be wiped using a new surface (unused area) of the wiping web 101.

  The wiping web 101 wiping the nozzle surface 33 is wound around the winding-side web core 103. Further, the head 32 is moved to the moisturizing position by the head support frame moving mechanism, and the nozzle surface 33 is covered with the cap 42.

<Electrical configuration of inkjet recording apparatus>
FIG. 8 is a block diagram showing an electrical configuration of the inkjet recording apparatus 10. As shown in the figure, the inkjet recording apparatus 10 includes a control unit 90, an operation unit 91, an image data acquisition unit 92, a discharge control unit 93, a head support frame control unit 94, a head support frame moving mechanism 95, and a cleaning device control unit. 96, a moisturizing unit controller 97, a pump 98, and the like.

  The control unit 90 performs overall control of the inkjet recording apparatus 10 in accordance with an input operation of the operation unit 91 by the user. The control unit 90 includes image processing means for converting the image data acquired by the image data acquisition unit 92 into ejection data for ejection from the nozzles 51 of the head 32.

  The operation unit 91 includes various operation members. The user can cause the inkjet recording apparatus 10 to perform a desired operation by operating the operation unit 91.

  The image data acquisition unit 92 includes a wired or wireless input interface, and acquires image data to be recorded in the head 32.

  The ejection control unit 93 controls each nozzle of each color head 32 based on the ejection data acquired from the control unit 90 and records an image on the recording surface of the paper P.

  The head support frame control unit 94 controls the head support frame moving mechanism 95 in accordance with a command from the control unit 90 and moves the head support frame 34 to move the head 32 to the image recording position or the moisturizing position.

  The cleaning device control unit 96 controls the nozzle surface cleaning device 80 in accordance with instructions from the control unit 90. That is, when wiping and cleaning the nozzle surface 33, the wiping device main body elevating mechanism is raised, and the application of the cleaning liquid by the cleaning liquid application unit 105 and the conveyance of the wiping web 101 are controlled in accordance with the arrival timing of the head 32.

  The moisturizing unit control unit 97 controls the moisturizing unit 40 in accordance with instructions from the control unit 90. That is, a pressurization / suction mechanism for pressurizing / suctioning the inside of the nozzle and a cleaning liquid supply mechanism for supplying a cleaning liquid into the cap 42 are controlled.

  The pump 98 and the ink tank 99 are provided for each ink color. The pump 98 (an example of the ink flow generation unit) is controlled by the control unit 90 and supplies the ink stored in the ink tank 99 (an example of the liquid tank) to the supply port 66 of each head module 32 ′. Further, the ink discharged from the discharge port 68 of each head module 32 ′ is sent to the ink tank 99. Thereby, the ink is circulated between the ink tank 99 and the head 32.

<Operation of inkjet recording apparatus>
FIG. 9 is a flowchart showing the operation of the inkjet recording apparatus 10. The ink jet recording apparatus 10 has a print mode (first mode) for moving the head 32 to a standby position and a print mode (second mode) for maintaining the head 32 at the image recording position when switching an image to be printed. Have.

  Hereafter, each process of operation | movement is demonstrated.

(Step S1)
Initially, the head 32 is located at the moisturizing position. As described above, in the ink jet recording apparatus 10, when the apparatus is stopped for a long time, the head 32 is moved to the moisturizing position, and the nozzle surface 33 is covered with the cap 42. Thereby, non-ejection due to drying of the nozzle 51 is prevented.

(Step S2)
Next, the set print mode is determined. The user can select one of the first mode and the second mode by operating the operation unit 91 (an example of a selection unit). The control unit 90 determines the print mode selected by the operation unit 91.

  First, the case where the first mode is set will be described.

(Step S3)
The user registers in advance the image to be recorded and the number of recordings via the operation unit 91 (an example of a registration unit).

  If it is determined that the mode is the first mode, the registered image data is acquired via the image data acquisition unit 92. At the same time, the number of sheets to be recorded is acquired.

(Step S4)
Further, the control unit 90 controls the head support frame moving mechanism via the head support frame control unit 94 to move the head 32 to the image recording position.

(Step S5)
The control unit 90 generates discharge data from the acquired image data, and inputs the discharge data to the discharge control unit 93. The discharge controller 93 controls the nozzles 51 of the head 32 based on the input discharge data, and records an image on the recording surface of the paper P. Here, recording is performed for the number of recordings acquired in step S3. The control unit 90 (an example of a counting unit) counts the total number of recorded sheets from the previous maintenance.

(Step S6)
It is determined whether or not the total number of recorded sheets from the previous maintenance is M or more. If the number is M or more, the process proceeds to step S7. If the number is less than M, the process proceeds to step S8.

(Step S7)
When the total number of recorded sheets from the previous maintenance is M or more, the head 32 is maintained. In the present embodiment, as the maintenance of the head 32, the nozzle surface 33 is wiped and cleaned by the nozzle surface cleaning device 80. That is, as described with reference to FIG. 7, the wiping web 101 that travels by being impregnated with the cleaning liquid is pressed against the pressure roll 107 to wipe the nozzle surface 33.

  In this way, the maintenance performance of the head 32 is periodically performed, so that the ejection performance of the head 32 is maintained. Also, by performing this maintenance, the total number of recorded sheets from the previous maintenance is cleared.

(Step S8)
In step S6, when it is determined that the total number of recorded sheets from the previous maintenance is less than M, or when the maintenance in step S7 is completed, the control unit 90 supports the head support via the head support frame control unit 94. The frame moving mechanism is controlled to move the head 32 to the moisturizing position.

(Step S9)
It is determined whether or not all images have been recorded. If all the images have been recorded, the process ends. Thus, drying of the nozzle 51 can be prevented by ending the processing with the head 32 being moved to the moisturizing position.

  If there are other images to be recorded, the process returns to step S2 to determine the set print mode. When the first mode is set, image data to be recorded next is acquired via the image data acquisition unit 92 (corresponding to image switching), and the same processing is performed.

  In this way, in the first mode, the head 32 moves to the moisturizing position each time the image to be recorded is switched, so that the nozzle 51 can be prevented from drying even when the image switching takes time. .

  Next, the case where the second mode is set in step S2 will be described. In this second mode, the user first registers all the combinations of images to be recorded and the number of recorded images regarding the recording of a plurality of images.

(Step S10)
If it is determined that the mode is the second mode, all the registered image data and the number of recorded images are acquired via the image data acquisition unit 92.

(Step S11)
Next, the control unit 90 controls the head support frame moving mechanism via the head support frame control unit 94 to move the head 32 to the image recording position.

(Step S12)
The control unit 90 generates ejection data of the first image data from the acquired plurality of image data, and inputs the ejection data to the ejection control unit 93. The discharge controller 93 controls the nozzles 51 of the head 32 based on the input discharge data, and records an image on the recording surface of the paper P. Here, recording is performed for the number of recordings acquired in step S10. Also, the total number of recorded sheets from the previous maintenance is counted.

  This process is repeated until the recording of all the image data acquired in step S10 is completed. Here, when the image to be printed is switched, the next image to be recorded and the number of recorded images are input again to the control unit 90, while the head 32 stands by at the image recording position.

(Step S13)
It is determined whether the total number of recorded sheets from the previous maintenance is N or more. Here, N satisfies the relationship N <M. If it is N or more, the process proceeds to step S14, and if it is less than N, the process proceeds to step S15.

(Step S14)
When the total number of recorded sheets from the previous maintenance is N or more, the head 32 is maintained. As in the first mode, the nozzle surface 33 is wiped and cleaned by the nozzle surface cleaning device 80 as maintenance of the head 32.

(Step S15)
In step S13, when it is determined that the total number of recorded sheets from the previous maintenance is less than N, or when the maintenance in step S14 is completed, the control unit 90 supports the head support via the head support frame control unit 94. The frame moving mechanism is controlled to move the head 32 to the moisturizing position.

(Step S16)
As described above, in the second mode, since the image to be printed is switched while the head 32 is maintained at the image recording position, the moving time of the head 32 becomes unnecessary, and the printing time can be shortened.

  When all the images have been recorded, the control unit 90 controls the head support frame moving mechanism via the head support frame control unit 94 to move the head 32 to the moisturizing position, and ends the process. Thus, drying of the nozzle 51 can be prevented by ending the processing with the head 32 being moved to the moisturizing position.

  As described above, in the first mode, the recording image is acquired (switched) in a state where the head 32 is in the moisturizing position, so that it is possible to prevent the nozzles from being dried while generating ejection data from the acquired image data. be able to.

  In the second mode, since the recorded image is acquired (switched) while the head 32 is maintained at the image recording position, the head 32 does not reciprocate between the image recording position and the moisturizing position. Time can be shortened.

  However, in the second mode, there is an increased risk of the nozzle drying out, so maintenance must be performed frequently. In particular, in this embodiment, since the ink containing latex is used, the ink is easily solidified. Accordingly, maintenance is performed when the number of printed sheets exceeds M sheets in the first mode, whereas maintenance is performed when the number of printed sheets exceeds N sheets smaller than M sheets in the second mode. .

  Thereby, maintenance can be appropriately performed according to the environment where the head is placed. In addition, when printing is performed in the second mode even once, maintenance is performed when the number of printed sheets exceeds N, which is smaller than M, so even if the mode is changed, Maintenance can be performed appropriately. In this embodiment, printing is performed on a sheet. However, the present invention can be applied in the same manner even in a mode of cutting after printing on roll paper.

  In the case of a so-called roll-to-roll printer, the print amount (for example, in units of meters) may be counted instead of the number of printed sheets.

<Another configuration example of the ink jet recording apparatus>
Next, another configuration example of the ink jet recording apparatus will be described. FIG. 10 is a diagram illustrating a configuration example of the inkjet recording apparatus 10 ′.

  The ink jet recording apparatus 10 ′ is a printing machine that forms a desired color image by ejecting a plurality of colors of ink from ink jet heads 172M, 172K, 172C, and 172Y onto a recording medium 124 held by a drawing drum 170 of a drawing unit 116. A two-liquid reaction (aggregation) in which a processing liquid (here, an aggregating processing liquid) is applied onto the recording medium 124 before ink droplet ejection, and the processing liquid and the ink liquid are reacted to form an image on the recording medium 124. ) Method is an on-demand type image forming apparatus.

  As shown in the figure, the ink jet recording apparatus 10 ′ mainly includes a paper feed unit 112, a treatment liquid application unit 114, a drawing unit 116, a drying unit 118, a fixing unit 120, and a paper discharge unit 122.

(Paper Feeder)
The paper supply unit 112 is a mechanism that supplies the recording medium 124 to the processing liquid application unit 114. A recording medium 124 that is a sheet is stacked on the paper feeding unit 112. The recording media 124 are fed one by one from the sheet feeding tray 150 of the sheet feeding unit 112 to the processing liquid applying unit 114. Here, a sheet (cut paper) is used as the recording medium 124, but a configuration in which continuous paper (roll paper) is cut to a required size and fed is also possible.

(Processing liquid application part)
The processing liquid application unit 114 is a mechanism that applies the processing liquid to the recording surface of the recording medium 124. The treatment liquid contains a color material aggregating agent that agglomerates the color material (pigment in this example) in the ink applied by the drawing unit 116, and the ink comes into contact with the treatment liquid and the ink. And the solvent are promoted.

  The processing liquid application unit 114 includes a paper feed cylinder 152, a processing liquid drum 154, a processing liquid coating device 156, and a processing liquid drying device 157. The processing liquid drum 154 includes a claw-shaped holding means (gripper) 155 on the outer peripheral surface thereof, and the recording medium 124 is sandwiched between the claw of the holding means 155 and the peripheral surface of the processing liquid drum 154. The tip can be held. The treatment liquid drum 154 may be provided with a suction hole on the outer peripheral surface thereof and connected to a suction unit that performs suction from the suction hole. As a result, the recording medium 124 can be held in close contact with the peripheral surface of the treatment liquid drum 154.

  A processing liquid coating device 156 is provided outside the processing liquid drum 154 so as to face the peripheral surface thereof. The processing liquid coating device 156 includes a processing liquid container in which the processing liquid is stored, an anix roller partially immersed in the processing liquid in the processing liquid container, and the recording medium 124 on the anix roller and the processing liquid drum 154. And a rubber roller that transfers the measured processing liquid to the recording medium 124. According to the processing liquid coating apparatus 156, the processing liquid can be applied to the recording medium 124 while being measured. In the present embodiment, the configuration in which the application method using the roller is exemplified, but the present invention is not limited to this. For example, various methods such as a spray method and an ink jet method can be applied.

  Further, the processing liquid application unit 114 includes a processing liquid drying device 157 for drying the solvent component in the processing liquid applied to the recording medium 124 by the processing liquid coating device 156. The treatment liquid drying device 157 is composed of, for example, a halogen heater.

  The recording medium 124 to which the processing liquid is applied by the processing liquid applying unit 114 is transferred from the processing liquid drum 154 to the drawing drum 170 of the drawing unit 116 via the intermediate transport unit 126.

(Drawing part)
The drawing unit 116 includes a drawing drum 170, inkjet heads 172 </ b> M, 172 </ b> K, 172 </ b> C, 172 </ b> Y (an example of a liquid discharge head), and a paper holding roller 174. Similar to the treatment liquid drum 154, the drawing drum 170 includes a claw-shaped holding means (gripper) 171 on the outer peripheral surface thereof.

  The inkjet heads 172M, 172K, 172C, and 172Y are full-line inkjet recording heads (inkjet heads) each having a length corresponding to the maximum width of the image forming area on the recording medium 124. Is formed with a nozzle row in which a plurality of nozzles for ink ejection are arranged over the entire width of the image forming area. Each inkjet head 172M, 172K, 172C, 172Y is installed so as to extend in a direction orthogonal to the conveyance direction of the recording medium 124 (the rotation direction of the drawing drum 170). The configuration of the inkjet heads 172M, 172K, 172C, and 172Y is the same as that of the head 32 shown in FIGS.

  The liquid droplets (liquid) of the corresponding color ink are ejected from the inkjet heads 172M, 172K, 172C, and 172Y toward the recording surface of the recording medium 124 held in close contact with the drawing drum 170, thereby applying the treatment liquid. The ink comes into contact with the processing liquid previously applied to the recording surface in the section 114, and the color material (pigment) dispersed in the ink is aggregated to form a color material aggregate. Thereby, the color material flow on the recording medium 124 is prevented, and an image is formed on the recording surface of the recording medium 124.

  That is, the recording medium 124 is transported at a constant speed by the drawing drum 170, and the operation of relatively moving the recording medium 124 and each of the inkjet heads 172M, 172K, 172C, 172Y in this transport direction is performed only once ( That is, an image can be recorded in the image forming area of the recording medium 124 (one example of recording means) by one sub-scanning. Single-pass image formation with such a full-line (page wide) head is a multi-pass with a serial (shuttle) type head that reciprocates in the direction (main scanning direction) orthogonal to the recording medium conveyance direction (sub-scanning direction). High-speed printing is possible as compared with the case where the method is applied, and print productivity can be improved.

  Note that the configuration is not limited to the CMYK standard color (four colors), and light ink, dark ink, and special color ink may be added as necessary. For example, it is possible to add an inkjet head that discharges light-colored ink such as light cyan and light magenta, and the arrangement order of the color heads is not particularly limited.

  Although not shown in FIG. 10, the drawing unit 116 includes a moisturizing unit 40 ′ and a nozzle surface cleaning device 80 ′.

  FIG. 11 is a plan view of the drawing unit 116. A moisturizing unit 40 'is arranged in a direction perpendicular to the conveying direction of the recording medium 124 of the drawing drum 170, and a nozzle surface cleaning device 80' is arranged between the drawing drum 170 and the moisturizing unit 40 '.

  Each inkjet head 172M, 172K, 172C, 172Y is attached to a head support frame (not shown). The head support frame is driven by a head support frame moving mechanism (not shown, an example of a moving unit), and an “image recording position” for printing on a recording medium held on the drawing drum 170, and a moisturizing unit 40 described later. It is provided so as to be movable between a “humidity holding position” where the nozzle surface is moisturized.

  The moisturizing unit 40 'includes caps 42M, 42K, 42C, 42Y, and a waste liquid tray 44 at a lower position thereof. The caps 42M, 42K, 42C, and 42Y cover the nozzle surfaces of the ink jet heads 172M, 172K, 172C, and 172Y moved by the head support frame moving mechanism, and are configured to be sealed.

  The nozzle surface cleaning device 80 ′ includes wiping units 100M ′, 100K ′, 100C ′, and 100Y ′ attached to the wiping device main body frame 82 ′, and a wiping device main body lifting mechanism (not shown) that moves the wiping device main body frame 82 ′ up and down. It consists of. The wiping units 100M ′, 100K ′, 100C ′, and 100Y ′ wipe and clean the nozzle surfaces of the inkjet heads 172M, 172K, 172C, and 172Y that move in the upper portion by the head support frame moving mechanism.

  The detailed configuration and operation of the moisturizing unit 40 ′ and the nozzle surface cleaning device 80 ′ are the same as those of the moisturizing unit 40 and the nozzle surface cleaning device 80 described above, and thus the description thereof is omitted here.

  The recording medium 124 on which an image is formed by the drawing unit 116 is transferred from the drawing drum 170 to the drying drum 176 of the drying unit 118 via the intermediate conveyance unit 128.

(Drying part)
The drying unit 118 is a mechanism for drying moisture contained in the solvent separated by the color material aggregating action, and includes a drying drum 176 and a solvent drying device 178. Similar to the processing liquid drum 154, the drying drum 176 includes a claw-shaped holding unit (gripper) 177 on the outer peripheral surface thereof, and the holding unit 177 can hold the leading end of the recording medium 124.

  The solvent drying device 178 is disposed at a position facing the outer peripheral surface of the drying drum 176, and includes a plurality of halogen heaters 180 and hot air ejection nozzles 182 disposed between the halogen heaters 180. Various drying conditions can be realized by appropriately adjusting the temperature and air volume of the hot air blown toward the recording medium 124 from each hot air ejection nozzle 182 and the temperature of each halogen heater 180.

  The recording medium 124 that has been dried by the drying unit 118 is transferred from the drying drum 176 to the fixing drum 184 of the fixing unit 120 via the intermediate conveyance unit 130.

(Fixing part)
The fixing unit 120 includes a fixing drum 184, a halogen heater 186, a fixing roller 188, and an inline sensor 190. Like the processing liquid drum 154, the fixing drum 184 includes a claw-shaped holding unit (gripper) 185 on the outer peripheral surface, and the leading end of the recording medium 124 can be held by the holding unit 185.

  With the rotation of the fixing drum 184, the recording medium 124 is conveyed with the recording surface facing outward. The recording surface is preheated by the halogen heater 186, fixing processing by the fixing roller 188, and by the inline sensor 190. Inspection is performed.

  The fixing roller 188 is a roller member that heats and pressurizes the dried ink to weld the self-dispersing polymer fine particles in the ink to form a film of the ink, and is configured to heat and press the recording medium 124. The The recording medium 124 is sandwiched between the fixing roller 188 and the fixing drum 184 and nipped with a predetermined nip pressure, and a fixing process is performed. The fixing roller 188 is configured by a heating roller incorporating a halogen lamp or the like, and is controlled to a predetermined temperature.

  The in-line sensor 190 reads an image (including a density correction test pattern, a non-ejection nozzle detection test pattern, a nozzle position association mark, and the like) formed on the recording medium 124, and determines the image density and the image density. A means for detecting defects and the like, and a CCD line sensor, a CCD camera, or the like is applied.

  Instead of ink containing a high boiling point solvent and polymer fine particles (thermoplastic resin particles), an ink containing a monomer component that can be polymerized and cured by ultraviolet (UV) exposure may be used. In this case, the inkjet recording apparatus 10 ′ is provided with means for irradiating actinic rays, such as a UV lamp or an ultraviolet LD (laser diode) array, instead of the fixing roller 188 for heat fixing.

(Output section)
Subsequent to the fixing unit 120, a paper discharge unit 122 is provided. The paper discharge unit 122 includes a discharge tray 192. Between the discharge tray 192 and the fixing drum 184 of the fixing unit 120, a transfer drum 194, a conveyance belt 196, and a stretching roller 198 are in contact with each other. Is provided. The recording medium 124 is sent to the conveyor belt 196 by the transfer drum 194 and discharged to the discharge tray 192. Although the details of the paper transport mechanism by the transport belt 196 are not shown, the recording medium 124 after printing is held at the front end of the paper by a gripper (not shown) gripped between the endless transport belt 196, and the transport belt 196. Is carried above the discharge tray 192.

  Although not shown in FIG. 10, in addition to the above-described configuration, the ink jet recording apparatus 10 ′ of this example includes an ink tank for storing ink and ink jet heads 172M, 172K, 172C, and 172Y. A pump for supplying and discharging ink, a means for supplying the processing liquid to the processing liquid applying unit 114, a position detection sensor for detecting the position of the recording medium 124 on the paper conveyance path, a temperature sensor for detecting the temperature of each part of the apparatus, An operation unit (selection unit) that can select one of the first mode and the second mode is provided.

<Example>
Using the inkjet recording apparatus 10 ′ shown in FIG. 10, the relationship between the maintenance frequency and the performance of the inkjet head was evaluated.

  First, in condition 1, as shown in FIG. 12A, the printing and maintenance on the A recording media 124 were repeated for three days.

  In condition 2, as shown in FIG. 12B, the printing on the B recording media 124 and the maintenance were repeated for three days. Here, B satisfies the relationship B> 2 × A.

  Furthermore, in condition 3, as shown in FIG. 12C, after printing on the A sheets of recording media 124, the image recording position was left for 30 minutes, and then maintenance was repeated for 3 days.

  In each condition, printing on the recording medium 124 was performed by dividing each color inkjet head 172M, 172K, 172C, 172Y into a printing module and a non-printing module, and printing a solid image (uniform density image) in the printing module.

  As maintenance, the nozzle surfaces of the inkjet heads 172M, 172K, 172C, and 172Y were wiped and cleaned in the wiping units 100M ′, 100K ′, 100C ′, and 100Y ′ of the nozzle surface cleaning device 80 ′.

  For each of these conditions, the landing position deviation of each color inkjet head was evaluated as an index indicating the performance of the inkjet head. The landing position misalignment was confirmed by selecting three printing modules and three non-printing modules for each color inkjet head, selecting three nozzles for each selected module, and printing an alignment chart at the selected nozzles. .

  FIG. 13 is a diagram showing the maximum value of σ of the absolute value of the landing position deviation of each inkjet head after the respective conditions shown in FIG. 12 are implemented. Here, the maximum value of the printing module, the maximum value of the non-printing module, and the average value thereof are shown. The case where σ ≦ 1.00 is determined as A, and the case where σ> 1.00 is determined as C.

  As shown in FIG. 13, all of the magenta ink and the black ink were judged as A in the conditions 1 to 3. However, cyan ink was judged as A in conditions 1 and 2, but in condition 3, σ> 1.00 for both the printing module and the non-printing module, and was judged as C.

  For yellow ink, A judgment was made under conditions 1 and 2, but under condition 3, σ> 1.00 for both the printing module and the non-printing module, and C judgment.

  If the inkjet head is left at the image recording position, the ejection performance of the inkjet head is deteriorated. In particular, in the inkjet recording apparatus 10 ′, the halogen heater of the treatment liquid drying device 157 of the treatment liquid application unit 114 and the drying drum 176 of the drying unit 118 are disposed in the vicinity of the drawing unit 116, and the image recording position is high. It has become.

  Therefore, if the image is switched while the inkjet head is kept waiting at the image recording position, the inkjet head is left in a high temperature atmosphere, and the ejection performance of the inkjet head is worse than when moving to the moisturizing position. Be in the situation.

  In condition 1 and condition 3, the number of printed sheets is the same, but the time left at the image recording position during maintenance is different. Therefore, it can be seen that if the time left at the image recording position is long, it is necessary to perform maintenance early. Further, under condition 2, since each color ink satisfies σ ≦ 1.00 and no abnormality is observed, it can be understood that there is no problem even if printing is continuously performed for B sheets without performing maintenance.

<Another operation example of inkjet recording apparatus>
FIG. 14 is a flowchart showing the operation of the inkjet recording apparatus 10. In addition, the same code | symbol is attached | subjected to the part which is common in the flowchart shown in FIG. 9, and the detailed description is abbreviate | omitted.

  The ink jet recording apparatus 10 has a print mode (third mode) in which the head 32 is moved to a standby position and a print mode (fourth mode) in which the head 32 is maintained at the image recording position when the image to be printed is switched. Have.

  The control unit 90 (an example of a time measuring unit) measures an elapsed time since the previous maintenance. In the third mode, when the recording of one image is completed, it is determined whether or not the elapsed time from the previous maintenance has become P minutes or more (step S21).

  If the elapsed time from the previous maintenance is less than P minutes, the head 32 is moved to the moisturizing position (step S8), and if it is more than P minutes, the nozzle surface 33 is wiped and cleaned by the nozzle surface cleaning device 80. After that (step S7), the head 32 is moved to the moisturizing position (step S8). Thereafter, new recorded image data is acquired (step S3).

  By operating in this way, the nozzle surface 33 can be appropriately moisturized even when it takes time to obtain the recorded image data and subsequent image processing.

  In the fourth mode, when all the images have been recorded, it is determined whether or not the elapsed time from the previous maintenance is equal to or longer than Q minutes (step S22).

  If the elapsed time from the previous maintenance is less than Q minutes, the process moves to the moisturizing position as it is (step S15). In the case of Q minutes or more, the nozzle surface cleaning device 80 wipes and cleans the nozzle surface 33 (step S14), and then moves to the moisturizing position (step S15).

  By operating in this way, the printing time can be shortened by an amount corresponding to the movement time between the image recording position of the head 32 and the moisturizing position.

  In the present embodiment, the relationship P> Q is satisfied. As described above, when the image is switched while the inkjet head is kept waiting at the image recording position, the ejection performance of the inkjet head becomes worse than when the image is moved to the moisturizing position. Therefore, by controlling in such a relationship, appropriate maintenance can be performed in consideration of the environment where the head is placed. In addition, when printing is performed in the fourth mode even once, maintenance is performed when the elapsed time exceeds Q minutes shorter than P minutes, so even if the mode is changed, Maintenance can be performed appropriately.

  The technical scope of the present invention is not limited to the scope described in the above embodiment. The configurations and the like in the embodiments can be appropriately combined between the embodiments without departing from the gist of the present invention.

  For example, in the first mode, maintenance is performed when the total number of recorded sheets from the previous maintenance is M or more, or when the elapsed time from the previous maintenance is P minutes or more, the second mode In this case, it is possible to perform maintenance when the total number of recorded sheets from the previous maintenance is N or more, or when the elapsed time from the previous maintenance is Q minutes or more. At this time, it goes without saying that the relationship of M> N and P> Q is satisfied.

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device, 20 ... Paper conveyance mechanism, 30 ... Head unit, 32 (32C, 32M, 32Y, 32K) ... Head, 33 ... Nozzle surface, 80 ... Nozzle surface cleaning device, 100 (100C, 100M, 100Y, 100 ...) wiping unit, 112 ... wiping web, 116 ... take-up web core, 107 ... pressing roll, 142 ... anilox roll, 200 ... maintenance control unit, 202 ... storage unit, 204 ... head support frame control unit, 208 DESCRIPTION OF SYMBOLS ... Web control part, 210 ... Winding motor, 212 ... Anilox roll control part, 214 ... Drive motor, 216 ... Wiping apparatus main body raising / lowering mechanism

Claims (10)

A liquid discharge head having a nozzle for discharging liquid;
A recording means for recording an image on the recording medium by discharging liquid from the nozzle while relatively moving the liquid discharging head and the recording medium;
Moisturizing means for moisturizing the nozzle of the liquid discharge head;
The liquid ejection head is moved to a standby position different from the recording position where the recording unit performs recording on the recording medium and the recording position where the nozzle is moisturized by the moisturizing unit . Transportation means;
The first mode in which the liquid ejection head is moved to the standby position when switching the image to be recorded by the recording means, and the liquid ejection head is maintained at the recording position when the image to be recorded by the recording means is switched. Selecting means for selecting one of the second modes;
Maintenance means for performing maintenance of the liquid discharge head;
Counting means for counting the number of recordings by the recording means from the time when maintenance by the maintenance means is performed;
Registration means for registering an image to be recorded by the recording means;
If the first mode is selected when all the recorded images have been recorded, maintenance by the maintenance means is performed when the number of recorded sheets exceeds the first number, and the second mode is selected. Control means for performing maintenance by the maintenance means when the number of recorded sheets exceeds a second number smaller than the first number when the mode is selected;
An image recording apparatus comprising: A liquid discharge head having a nozzle for discharging liquid;
A recording means for recording an image on the recording medium by discharging liquid from the nozzle while relatively moving the liquid discharging head and the recording medium;
Moisturizing means for moisturizing the nozzle of the liquid discharge head;
The liquid ejection head is moved to a standby position different from the recording position where the recording unit performs recording on the recording medium and the recording position where the nozzle is moisturized by the moisturizing unit . Transportation means;
The first mode in which the liquid ejection head is moved to the standby position when switching the image to be recorded by the recording means, and the liquid ejection head is maintained at the recording position when the image to be recorded by the recording means is switched. Selecting means for selecting one of the second modes;
Maintenance means for performing maintenance of the liquid discharge head;
Time measuring means for measuring the holding time during which the liquid discharge head is held at the recording position from the time when maintenance is performed by the maintenance means;
Registration means for registering an image to be recorded by the recording means;
When the first mode is selected when all the recorded images have been recorded, if the holding time exceeds the first time, maintenance is performed by the maintenance means, and the first mode is selected. Control means for performing maintenance by the maintenance means when the holding time exceeds a second time shorter than the first time when the second mode is selected;
An image recording apparatus comprising: The maintenance unit, the image recording apparatus according to claim 1 or 2 is disposed between the recording position and the standby position. The maintenance unit, an image recording apparatus according to any one of claims 1 to 3 comprising a wiping means for wiping the liquid ejection surface of the liquid ejection head. The liquid, an image recording apparatus according to any one of claims 1 to 4 comprising a latex. The liquid discharge head includes a liquid supply port that supplies liquid to the nozzle, a liquid discharge port that discharges liquid that is not discharged from the nozzle,
In addition,
A liquid tank in which the liquid is stored;
An ink flow generating means for supplying the liquid from the liquid tank to the liquid supply port and for collecting the liquid from the liquid discharge port to the liquid tank;
An image recording apparatus according to any one of claims 1 to 5 , further comprising: The recording means the processing liquid to the recording medium before the image is recorded and applied by any treatment liquid deposition device of drying the applied the treatment liquid according to claim 1 to 6 which is disposed in proximity to the recording position The image recording apparatus according to claim 1. The image recording apparatus according to any one of the recording the discharged liquid medium from claim 1, which is arranged close to the then drying means the recording position drying 7 by the recording means. A liquid discharge head having nozzles for ejecting liquid, while relatively moving the recording medium and the liquid ejection head, a recording unit for recording an image on said recording medium by ejecting liquid from the nozzle, the Moisturizing means for moisturizing the nozzles of the liquid discharge head, a recording position for recording on the recording medium by the recording means, and a standby position different from the recording position, and a moisturizing position for moisturizing the nozzles by the moisturizing means a moving means for moving the liquid discharge head to the standby position is a first mode for moving the liquid ejection head when switching the image to be recorded by said recording means to the standby position, recorded by the recording means One mode of the second mode in which the liquid ejection head is maintained at the recording position when switching the image to be performed. Selecting means for-option, a control method of an image recording apparatus and a maintenance unit for performing maintenance of the liquid ejecting head,
A counting step of counting the number of recorded sheets by the recording means from the time when maintenance by the maintenance means is performed;
A registration step of registering an image to be recorded by the recording means;
If the first mode is selected when all the recorded images have been recorded, maintenance by the maintenance means is performed when the number of recorded sheets exceeds the first number, and the second mode is selected. A control step of performing maintenance by the maintenance means when the number of recorded sheets exceeds a second number smaller than the first number when the mode is selected;
A method for controlling an image recording apparatus comprising: A liquid discharge head having nozzles for ejecting liquid, while relatively moving the recording medium and the liquid ejection head, a recording unit for recording an image on said recording medium by ejecting liquid from the nozzle, the Moisturizing means for moisturizing the nozzles of the liquid discharge head, a recording position for recording on the recording medium by the recording means, and a standby position different from the recording position, and a moisturizing position for moisturizing the nozzles by the moisturizing means a moving means for moving the liquid discharge head to the standby position is a first mode for moving the liquid ejection head when switching the image to be recorded by said recording means to the standby position, recorded by the recording means One mode of the second mode in which the liquid ejection head is maintained at the recording position when switching the image to be performed. Selecting means for-option, a control method of an image recording apparatus and a maintenance unit for performing maintenance of the liquid ejecting head,
A time measuring step of measuring a holding time in which the liquid discharge head is held at the recording position from the time when maintenance is performed by the maintenance means;
A registration step of registering an image to be recorded by the recording means;
When the first mode is selected when all the recorded images have been recorded, if the holding time exceeds the first time, maintenance is performed by the maintenance means, and the first mode is selected. A control step of performing maintenance by the maintenance means when the holding time exceeds a second time shorter than the first time when the second mode is selected;
A method for controlling an image recording apparatus comprising:

Images