JP3674577B2 - Inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an ink jet printer that prints an image on a long print medium to be conveyed.
[0002]
[Prior art]
  Inkjet printers perform printing by spraying liquid ink onto paper. The ink jet printer has a print head in which a plurality of ejection nozzles for ejecting ink are arranged, and printing is performed while the print head reciprocates in a direction perpendicular to the paper transport direction. Is common.
[0003]
  Here, in a printing head of such an ink jet printer, if printing is not performed (no ink is ejected) and left for a long time, the ink near the opening of the ejection nozzle may dry and become clogged. . Therefore, when printing is not performed for a long time, the opening of the discharge nozzle is often sealed with a cap or the like. However, even when left in a sealed state for a long time, the viscosity of the ink near the opening of the discharge nozzle gradually increases, so that printing cannot be started immediately or the image to be printed May get worse.
[0004]
  In addition, in an ink jet printer capable of printing color images, even when printing is performed continuously for a long time, depending on the color of the ink, ejection nozzles that eject ink frequently and ejection that eject ink less frequently There is a nozzle, and new ink is sequentially supplied in the vicinity of the opening of the discharge nozzle where ink is frequently discharged, so clogging is unlikely to occur, but new ink is near the opening of the discharge nozzle where ink is not discharged frequently. Are difficult to be supplied, and the ink is dry and easily clogged.
[0005]
  Therefore, in order to solve the problem that the image is deteriorated due to clogging of the discharge nozzle, ink is forcibly discharged from each discharge nozzle regardless of printing, and the viscosity near the opening of the discharge nozzle is increased. In many cases, a print head cleaning operation such as a flushing operation for discharging discharged ink or a wiping operation for removing ink having a high viscosity from the vicinity of the opening of the discharge nozzle by wiping the vicinity of the opening of the discharge nozzle is performed.
[0006]
  In addition, in an inkjet large-sized printer, the discharge nozzles are not clogged by monitoring the ink discharged from the plurality of discharge nozzles during the above-described flushing operation using laser light (dots in the printed image). Some of them are provided with a dot dropout detecting device for detecting that no dropout occurs.
[0007]
[Problems to be solved by the invention]
  As described above, the frequency of occurrence of clogging of the discharge nozzles can be reduced by performing the print head cleaning operation as needed. However, if the discharge nozzle is still clogged after the print head cleaning operation has been performed, the discharge nozzle is clogged until the image actually printed on the paper is visually confirmed. It is difficult to notice (abnormality of the print head). Accordingly, when a large amount of printing has already been performed when an abnormality of the print head is noticed after printing is started, it takes a lot of time and cost to restart printing.
[0008]
  Further, in such an ink jet type large-sized printer, by providing a dot dropout detecting device, the size of the device increases, and the manufacturing cost for the printer device increases remarkably. Furthermore, when the ink ejected from the ejection nozzle during the flushing operation is monitored by the dot missing detection device, the print head is once displaced from the printable area in order to confirm that the ejection nozzle is not clogged. Often have to move to a different position. Accordingly, the processing capability of the printer is reduced by the amount that the print head is moved to a position shifted from the printable area.
[0009]
  Therefore, a main object of the present invention is to provide an ink jet printer that can suppress deterioration of a print image printed on a print medium due to an abnormality of a printing unit.
[0010]
[Means for Solving the Problems]
  In order to achieve the above object, an ink jet printer according to a first aspect of the present invention includes a transport unit that transports a print medium and a plurality of discharge nozzles that discharge ink to the print medium transported by the transport unit. And a downstream side of the printing unit for printing the print image based on the confirmation image and print data formed by ejecting ink from the plurality of ejection nozzles, and the surface of the printing medium A state detection unit for detecting the state of the printing unit based on data corresponding to the confirmation image read by the reading unit;A print image is printed so that image areas and non-image areas are alternately and continuously formed along the conveyance direction of the print medium, and a confirmation image is printed on at least one of the non-image areas. Control means for controlling the printing section, and a mark The printed print medium is arranged downstream of the reading unit for cutting the printed medium at a position substantially corresponding to the end of the non-image area in the conveyance direction of the print medium along the width direction of the print medium. Cutting part andIt is characterized by having.
[0011]
  According to the first aspect, based on the confirmation image printed on the printing medium by the printing unit, it is possible to detect the state of the printing unit, such as whether or not there is an abnormality in the printing unit. Therefore, it is possible to suppress a decrease in the processing capacity of the printer in order to check the state of the printing unit. Furthermore, a separate device for confirming the state of the printing unit is not required. Thereby, it is possible to suppress an increase in the manufacturing cost of the printer device while increasing the size of the printer device.
[0012]
  Also,After printing the confirmation image and the print image continuously on the print medium, only the non-image area (including the area corresponding to the confirmation image) other than the image area corresponding to the print image is cut and discarded. Therefore, it is possible to prevent the print medium from being wasted.Therefore, by utilizing this discarded portion as a region for printing the confirmation image, it is possible to suppress the loss of the print medium and the loss of processing capability in order to print the confirmation image.
[0013]
  Claims2The inkjet printer includes a control unit for controlling the printing unit so that printing of a print image on a printing medium is started when the state detection unit detects that the state of the printing unit is normal. Furthermore, it is characterized by providing.
[0014]
  Claim2According to the above, since it is confirmed that there is no abnormality in the print unit, printing of the print image on the print medium is started, so that the print image printed on the print medium is deteriorated due to the abnormality of the print unit. Can be suppressed. Therefore, a situation in which printing has to be performed again due to an abnormality in the printing unit hardly occurs.
[0015]
  Claims3In the ink jet printer, the control unit controls the printing unit so that printing of an image on a printing medium is stopped when the state detecting unit detects that the state of the printing unit is abnormal. It is characterized by this.
[0016]
  Claim3According to the above, when it is confirmed that there is an abnormality in the printing unit, printing of the print image on the printing medium is stopped, so that the printing medium is wasted due to misprinting (printing in a state where there is an abnormality in the printing unit). Can be suppressed.
[0017]
  Claims4In the inkjet printer, the confirmation image is formed by ejecting ink from all of the plurality of ejection nozzles by a flushing operation in the printing unit.
[0018]
  Claim4According to the present invention, during the flushing operation in the printing unit, the state of the printing unit is confirmed based on the confirmation image printed on the print medium by ejecting ink from all the ejection nozzles. There is almost no misprinting caused by the abnormality.
[0019]
  Claims5In the ink jet printer, the reading unit is provided so as to be close to the printing unit. Claim5According to the above, since printing of the print image is started from an area close to the area where the confirmation image on the print medium is printed, the print medium is transported between the confirmation image and the print image on the print medium. The distance in the direction can be reduced. Therefore, it is possible to prevent the printing medium and ink from being wasted. If the printing unit can reciprocate in a direction perpendicular to the conveyance direction of the print medium, the reading unit can be reduced in size by moving the reading unit together with the printing unit. Thus, the configuration of the reading unit can be simplified and can be manufactured at low cost.
[0020]
  Claims6In the ink jet printer, when the control unit prints a plurality of print images on the print medium in succession, a confirmation image is always printed before printing of each print image is started. As described above, the printing unit is controlled.
[0021]
  Claim6According to the above, since it is confirmed that there is no abnormality in the print unit immediately before each of the plurality of print images is printed, it is more effective that the print image printed on the print medium is deteriorated due to the abnormality of the print unit. Can be suppressed. In addition, when an abnormality occurs in the print unit, the print image on the print medium is printed before starting the printing of the next print image (at the end of printing of the print image being printed when an abnormality occurs in the print unit). Since printing is stopped, it is possible to effectively prevent the printing medium from being wasted due to misprinting.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of the ink jet printer according to the first embodiment.
[0023]
  An ink jet printer 1 shown in FIG. 1 includes a transport base 4, an ink jet printing unit 5, an image reading unit 6, a cutting unit 7, a transport roller unit 8, and a pressure roller unit within a substantially rectangular housing 30. 9 and a discharge roller unit 10. In the casing 30, a long sheet 2 on which a winding part 2a wound in a roll shape is formed is disposed. The winding portion 2a of the paper 2 is held by a drum 3 that can be rotated about the axis center. Further, as will be described later, the operation of each part of the ink jet printer 1 is controlled by a controller 20 disposed in the housing 30.
[0024]
  The transport roller unit 8 is a pair of drive rollers driven by a motor 25 controlled by the controller 20, and is for transporting the paper 2 before being cut by the cutting unit 7. That is, the transport roller unit 8 unwinds the paper 2 from the winding unit 2 a and transports the paper 2 on the transport table 4 to the downstream side, and sequentially passes through the inkjet printing unit 5, the image reading unit 6, and the cutting unit 7. Since the sheet 2 conveyed between the image reading unit 6 and the cutting unit 7 is sandwiched by the pressure roller unit 9, the image is printed by the inkjet printing unit 5, and the image is read and cut by the image reading unit 6. It becomes possible to appropriately cut the sheet 2 by the unit 7.
[0025]
  The ink jet printing unit 5 includes a print head 11, a carriage 12 that holds the print head 11, and a suction fan 13. The print head 11 includes a number of discharge nozzles 15 (see FIG. 3) that can discharge color inks such as yellow (yellow), magenta (red purple), cyan (blue green), and black. Therefore, the print head 11 discharges the color ink from the large number of discharge nozzles 15 toward the front surface (upper surface in FIG. 1) of the conveyed paper 2 based on the signal from the controller 20, respectively. Color images can be printed. In addition, the number and arrangement | positioning of the discharge nozzle 15 can be changed arbitrarily. The print head 11 may have a discharge nozzle that discharges only black ink, and may print a black and white image.
[0026]
  The ink jet printing unit 5 ejects liquid ink from the nozzles for each dot and prints on the paper 2 and adopts any one of the piezo jet method, the thermal jet method, and other methods. Also good.
[0027]
  Further, in the print head 11 of the ink jet printing unit 5, a flushing operation is appropriately executed in order to prevent clogging of the discharge nozzle 15 during printing. In the flushing operation of the print head 11, as described above, a predetermined amount of ink is forcibly ejected onto the paper 2 from all of the ejection nozzles 15 regardless of printing. Therefore, from all of the ejection nozzles 15, a predetermined amount of ink and ink with increased viscosity in the vicinity of the respective openings of the ejection nozzles 15 are discharged, and a flushing image is printed on the paper 2.
[0028]
  Here, the flushing image is printed by ejecting ink from all of the ejection nozzles 15 by the flushing operation, but the ink ejected from each ejection nozzle 15 is ejected so as not to overlap each other on the paper 2. . Therefore, for example, when a part of the ejection nozzle 15 is clogged, ink is not ejected from the ejection nozzle 15, and the ink lands on the position corresponding to the ejection nozzle 15 on the paper 2. Therefore, a blank is formed in the area where the flushing image on the paper 2 is printed. Even when clogging of a part of the discharge nozzle 15 is beginning to occur, the amount of ink discharged from the discharge nozzle 15 is reduced even when the ink is not completely blocked until no ink is discharged. A blank is formed in the area where the upper flushing image is printed. Thus, the clogged state of the discharge nozzles 15 of the print head 11 can be known from the flushing image printed on the paper 2 by the flushing operation of the print head 11.
[0029]
  Note that the timing at which the flushing operation of the print head 11 is performed may be performed only at the start of printing, for example, or may be performed every fixed number of shots (the number of times ink is ejected from each ejection nozzle 15). Alternatively, it may be performed every time a predetermined number of images are formed, and is preferably set according to the printing conditions. Similarly, the amount of ink ejected from each ejection nozzle 15 and the number of shots during the flushing operation are preferably set in accordance with the printing conditions.
[0030]
  The carriage 12 can reciprocate with the print head 11 in a direction perpendicular to the conveyance direction of the paper 2. Accordingly, the print head 11 ejects ink toward the surface of the paper 2 while reciprocating in a direction perpendicular to the conveyance direction of the paper 2. The suction fan 13 is disposed at a position facing the print head 11 across the transport path of the paper 2, and sucks the paper on the transport base 4 through an opening (not shown) formed in the transport base 4. Is for. Accordingly, the sheet 2 facing the print head 11 is conveyed in close contact with the conveyance table 4 by being sucked by the suction fan 13 disposed on the back surface (lower surface in FIG. 1) of the sheet 2. The interval between is fixed. This is to suppress the occurrence of printing defects due to a change in the distance from the print head 11 when a part of the sheet 2 is greatly separated from the transport table 4 when the sheet 2 is curled.
[0031]
  The image reading unit 6 includes a reading head 6 a that is a linear optical sensor having a width equal to or larger than the width of the paper 2, and is disposed between the ink jet printing unit 5 and the pressure roller unit 9. ing. The inkjet printing unit 5 and the image reading unit 6 are preferably arranged as close as possible. The image reading unit 6 can continuously read the surface of the printed paper 2 that has been conveyed to the reading position facing the reading head 6a. The data read by the image reading unit 6 is continuously supplied to the controller 20. Note that the reading of the surface of the sheet 2 in the image reading unit 6 is not necessarily performed continuously, and may be changed within a range in which the same function as in the present embodiment can be obtained, for example, intermittent reading. Can do.
[0032]
  The cutting unit 7 includes a moving blade 7a disposed on the same side as the ink jet printing unit 5 with respect to the paper 2, and a fixed blade 7b disposed so as to face the moving blade 7a with the paper 2 interposed therebetween. Yes. Both the fixed blade 7 b and the movable blade 7 a are rectangular blades having a width slightly larger than the width of the paper 2. The movable blade 7a can be moved closer to or away from the fixed blade 7b by a motor 27 controlled by the controller 20, and the printed paper 2 conveyed from the upstream side through the conveyance path can be removed. By the interaction with the fixed blade 7b, it can be cut along the width direction. By cutting in this way, the printed paper 2 having a predetermined length is divided.
[0033]
  The discharge roller unit 10 is a pair of drive rollers driven by a motor 26 controlled by the controller 20, and conveys the printed paper 2 that has been cut by the cutting unit 7 and discharges it from the discharge port 30a.
[0034]
  The controller 20 performs predetermined processing on an image signal supplied from an input interface (not shown) and supplies a print signal including image data corresponding to an image to be printed to the inkjet printing unit 5. Further, the controller 20 supplies drive signals to the motors 25, 26, and 27 and receives image data read by the image reading unit 6.
[0035]
  The controller 20 includes hardware such as a CPU, a ROM, and a RAM that are controlled by appropriate software, and includes a clogging detection unit 21 and a control unit 22.
[0036]
  Based on the image data corresponding to the flushing image supplied from the image reading unit 6, the clogging detection unit 21 determines whether clogging has occurred in each of the discharge nozzles 15 of the print head 11 (discharge of the print head 11). Whether the nozzle 15 is appropriate) can be detected.
[0037]
  The control unit 22 can control the print head 11 to print the flushing image on the paper 2 by the flushing operation before starting the printing of the image. In addition, when the clogging detection unit 21 determines that the clogging of all the discharge nozzles 15 of the print head 11 is not clogged, the control unit 22 starts printing an image on the paper 2. The print head 11 can be controlled. On the other hand, if it is determined that at least one of the ejection nozzles 15 of the print head 11 is clogged, the cleaning operation of the print head 11 is executed before printing of an image on the paper 2 is started. Can do. The cleaning operation of the print head 11 may be performed automatically or manually.
[0038]
  Here, in the present embodiment, the wiping operation of the print head 11 is performed as the cleaning operation of the print head 11. In the wiping operation of the print head 11, the vicinity of the opening of the discharge nozzle is wiped with a rubber-like member or the like, so that the ink having a high viscosity is removed from the vicinity of the opening of the discharge nozzle. Thereby, the clogging generated in the discharge nozzle 15 is eliminated. Note that the cleaning operation of the print head 11 is not limited to the wiping operation of the print head 11 and may be any operation as long as it has the same effect.
[0039]
  Therefore, as described above, the flushing operation of the print head 11 similar to that performed during the printing operation is opposed to the flushing receiving portion (not shown) provided at a position where the print head 11 is displaced from the printable area. It may be performed after being moved to a position. In this case, for example, the amount of ink or the number of shots forcibly ejected from the ejection nozzles is increased so that the clogging of the ejection nozzles 15 can be effectively eliminated compared to the flushing operation performed during the printing operation. It is preferable.
[0040]
  Next, the printing operation of the ink jet printer 1 configured as described above will be described with reference to FIGS. FIG. 2 is a flowchart showing a procedure of a printing operation in the ink jet printer of FIG. FIG. 3 is a diagram for explaining a printing operation in the ink jet printer of FIG.
[0041]
  First, when the leading end of the sheet 2 unwound from the winding unit 2a by the transport roller unit 8 is transported to a position facing the print head 11, the flushing image 50 is flushed by the flushing operation of the print head 11 in step S1. Is printed (see FIG. 3A). Here, as described above, the flushing image 50 is printed by ejecting ink from all the ejection nozzles 15 arranged in the print head 11 so as not to overlap each other on the paper 2. Accordingly, it can be confirmed whether or not clogging has occurred in all of the plurality of discharge nozzles 15.
[0042]
  Subsequently, when the sheet 2 is conveyed and the portion on which the flushing image 50 of the sheet 2 is printed is conveyed to a position facing the reading head 6a of the image reading unit 6, the flushing image 50 is read by the reading head 6a in step S2. Is read (see FIG. 3B).
[0043]
  In step S3, the clogging detection unit 21 determines whether clogging has occurred in the discharge nozzles 15 of the print head 11 based on the flushing image 50 read by the reading head 6a in step S2. . If all the discharge nozzles 15 are not clogged (S3: YES), the process proceeds to step S4. On the other hand, if at least one of the discharge nozzles 15 is clogged, the process proceeds to step S6.
[0044]
  As described above, when it is confirmed in step S3 that all the ejection nozzles 15 are not clogged, the printing operation of the image 60 based on the print signal is executed in step S4 (FIG. 3C). reference).
[0045]
  When the printing of the image 60 is completed, it is determined in step S5 whether or not the image is the last image of a plurality of images that are continuously printed based on the print signal. If it is not the last image (S5: NO), the process returns to step S1 and the same processing as described above is repeated. That is, when the printing of the image 60 is completed, the flushing image 51 is printed. When it is confirmed that all the ejection nozzles 15 are not clogged based on the flushing image 51, the image 61 based on the print signal is displayed. A printing operation is executed. By repeating such an operation, after the image 61 is printed, the flushing image 52, the image 62, and the flushing image 53 are printed in this order (see FIG. 3D). Then, when printing of the last image of the plurality of images that are continuously printed based on the print signal is finished (S5: YES), the processing is finished.
[0046]
  Here, in the present embodiment, the area where the flushing image (for example, the flushing image 50) is printed is the leading edge of the paper 2 or between the image to be printed (for example, between the image 60 and the image 61). ) And is included in a portion (discard portion) that is later cut and discarded by the cutting unit 7. That is, when borderless printing is performed in the roll process as in the present embodiment, the process of cutting from both sides is performed in the vicinity of the boundary line of the adjacent printed image. A portion to be discarded is formed in between. Therefore, by utilizing this discarded portion as a region for printing the flushing image, it is possible to suppress the loss of the sheet 2 and the loss of processing capability in order to print the flushing image.
[0047]
  In the present embodiment, margins are provided on both sides of the flushing image (between the flushing image) so that the image is not stained by the ink ejected by the flushing operation of the print head 11. However, the margin part is not necessarily provided.
[0048]
  On the other hand, if it is confirmed in step S3 that at least one of the discharge nozzles 15 is clogged, the cleaning operation of the print head 11 is executed in step S6. When the cleaning operation of the print head 11 is completed, the process returns to step S1 and the same process as described above is repeated. That is, when the flushing image is printed and read, and it is confirmed whether or not the ejection nozzle 15 is clogged by the cleaning operation of the print head 11, the clogging of the ejection nozzle 15 is eliminated. The image is printed.
[0049]
  Thereafter, the sheet 2 is transported, and the sheet 2 is cut each time the leading end and the rear end of the portion on which the image of the sheet 2 is printed are transported to a position facing the moving blade 7a of the cutting unit 7. The Then, the cut sheet 2 (including the portion on which the flushing image is printed) between the images is discarded.
[0050]
  As described above, according to the ink jet printer 1 of the present embodiment, the discharge nozzle 15 of the print head 11 is clogged based on the flushing image printed on the paper 2 by the flushing operation of the print head 11. You can check if there is any. Accordingly, it is possible to suppress a decrease in the processing capability of the ink jet printer 1 in order to check the state of the print head 11. Furthermore, a separate device for confirming the state of the print head 11 is not required. Thereby, it is possible to suppress the increase in the manufacturing cost of the printer device while increasing the size of the ink jet printer 1.
[0051]
  Further, after the flushing image and the image are continuously printed on the long paper 2, only the region other than the region corresponding to the image (including the region corresponding to the flushing image) is cut and discarded. Therefore, it is possible to prevent the paper 2 from being wasted.Therefore, by utilizing this discarded portion as a region for printing the confirmation image, it is possible to suppress the loss of the print medium and the loss of processing capability in order to print the confirmation image.
[0052]
  Further, since it is confirmed that there is no abnormality in the print head 11, that is, the clogging of the discharge nozzle 15 of the print head 11 has not occurred, the printing of the image on the paper 2 is started. It is possible to suppress the deterioration of the image printed on the paper 2 due to the abnormality. Therefore, a situation in which printing must be performed again due to an abnormality in the print head 11 hardly occurs.
[0053]
  Further, when it is confirmed that there is an abnormality in the print head 11, that is, clogging has occurred in the discharge nozzle 15 of the print head 11, the printing of the image on the paper 2 is stopped. 2 can be prevented from being wasted.
[0054]
  Further, during the flushing operation in the print head 11, the state of the print head 11 is confirmed based on the flushing image printed on the paper 2 by ejecting ink from all the ejection nozzles 15. Misprints due to head abnormalities rarely occur.
[0055]
  Further, the reading head 6a is provided so as to be close to the print head 11, and printing of an image is started from an area close to the area where the flushing image of the paper 2 is printed. The distance in the direction along the conveyance direction of the sheet 2 between the image and the image can be reduced. Therefore, it is possible to prevent the paper 2 and ink from being wasted.
[0056]
  In addition, since it is confirmed that there is no abnormality in the print head 11 immediately before printing a plurality of images, it is more effective that the image printed on the paper 2 deteriorates due to the abnormality in the print head 11. Can be suppressed. In addition, when an abnormality occurs in the print head 11, the image is printed on the paper 2 before starting the printing of the next image (at the end of printing the image being printed when the abnormality occurs in the print head 11). Therefore, it is possible to effectively prevent the sheet 2 from being wasted due to misprinting.
[0057]
  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims. Is. For example, in the first and second embodiments described above, it is determined that the state of the print head is normal (not abnormal) by confirming that all the ejection nozzles of the print head are not clogged. In this case, the abnormality of the print head includes things other than clogging of the discharge nozzle such as, for example, the landing positions of the reciprocating bidirectional ink are shifted (a gap occurs in the discharge nozzle). In other words, in the above-described embodiment, when it is confirmed that the state of the print head is not abnormal based on the flushing image, the print head is free from clogging of the discharge nozzle and all other abnormalities. As described.
[0058]
  In the first and second embodiments described above, a long sheet is used as a print medium. However, the present invention is not limited to this, and a sheet that has been cut into a predetermined length (predetermined size) in advance is used. May be used. In this case, a cutting unit for cutting the paper may not be provided. As the print medium, a thin plastic or the like can be used in addition to the paper.
[0059]
  In the above-described first and second embodiments, the state of the print head (based on the flushing image formed by ejecting ink from all of the plurality of ejection nozzles by the flushing operation of the print head ( However, the present invention is not limited to this, and the confirmation image for detecting the state of the print head can confirm the state of the print head. If it exists, it may be other than the flushing image. Therefore, the state of the print head may be confirmed based on the check pattern printed on the paper. Here, as the check pattern, for example, there is a lattice pattern including a large number of lines printed for each color in a rectangular range over the entire width of the sheet. That is, if the check pattern is printed without missing each color line, it can be confirmed that all the plurality of ejection nozzles are not clogged.
[0060]
  Here, the flushing image and the check pattern are not necessarily formed by ejecting ink from all of the plurality of ejection nozzles, and may be formed by ejecting ink from some of the plurality of ejection nozzles. That is, if the ejection nozzles necessary for printing an image can be detected from the data to be printed, the flushing image and the check pattern may be formed by ejecting ink from only the corresponding ejection nozzles. Therefore, in this case, confirmation images such as a flushing image and a check pattern are printed without ejecting ink from ejection nozzles that are not necessary for printing an image.
[0061]
  In the first and second embodiments described above, printing of an image on the paper 2 is started when it is determined that all the ejection nozzles of the print head are not clogged based on the flushing image. In addition, a case will be described in which a control unit that controls the print head to stop printing an image on the paper 2 when it is determined that a part of the ejection nozzles of the print head is clogged is described. However, the control unit is not necessarily provided. Therefore, if the control unit is not provided, after the state of the print head is detected based on the flushing image, the printer is operated to start printing or stop printing based on the detected result. There is a need to do. Further, even if a control unit is provided, it may be possible to control only one of printing start and printing stop.
[0062]
  In the first and second embodiments described above, the case where the print head and the reading head are provided so as to be close to each other has been described. However, they are not necessarily provided so as to be close to each other. Good.
[0063]
  In the first and second embodiments described above, the case where the surface of the printed paper is continuously read by the reading head has been described. However, the surface of the printed paper is not necessarily read continuously. For example, it may be read intermittently at a predetermined time interval.
[0064]
  In the first embodiment described above, the case where the flushing image is always printed before the printing of each image is described. However, the printing is not necessarily performed before the printing of each image is started. The flushing image is not necessarily printed, and the flushing image may be printed every time a predetermined number of images are printed.
[0065]
  In the first and second embodiments described above, a case has been described in which a borderless image in which no margin is formed around the image area is printed as the print image. However, the present invention is not limited to this. A bordered image in which a margin is formed around the area may be printed.
[0066]
【The invention's effect】
  As described above, according to the first aspect, based on the confirmation image printed on the print medium by the printing unit, for example, the state of the printing unit such as whether or not there is an abnormality in the printing unit can be detected. it can. Therefore, it is possible to suppress a decrease in the processing capacity of the printer in order to check the state of the printing unit. Furthermore, a separate device for confirming the state of the printing unit is not required. Thereby, it is possible to suppress an increase in the manufacturing cost of the printer device while increasing the size of the printer device.
[0067]
  Also,After printing the confirmation image and the print image continuously on the print medium, only the area other than the area corresponding to the print image (including the area corresponding to the confirmation image) may be cut and discarded. Therefore, it is possible to prevent the print medium from being wasted.Therefore, by utilizing this discarded portion as a region for printing the confirmation image, it is possible to suppress the loss of the print medium and the loss of processing capability in order to print the confirmation image.
[0068]
  Claim2According to the above, since it is confirmed that there is no abnormality in the print unit, printing of the print image on the print medium is started, so that the print image printed on the print medium is deteriorated due to the abnormality of the print unit. Can be suppressed. Therefore, a situation in which printing has to be performed again due to an abnormality in the printing unit hardly occurs.
[0069]
  Claim3According to this, when it is confirmed that there is an abnormality in the printing unit, printing of the print image on the printing medium is stopped, so that the printing medium is wasted due to misprinting (printing in a state where there is an abnormality in the printing unit). Can be suppressed.
[0070]
  Claim4According to the present invention, during the flushing operation in the printing unit, the state of the printing unit is confirmed based on the confirmation image printed on the print medium by ejecting ink from all the ejection nozzles. There is almost no misprinting caused by the abnormality.
[0071]
  Claim5According to the above, since printing of the print image is started from an area close to the area where the confirmation image on the print medium is printed, the print medium is transported between the confirmation image and the print image on the print medium. The distance in the direction can be reduced. Therefore, it is possible to prevent the printing medium and ink from being wasted. If the printing unit can reciprocate in a direction perpendicular to the conveyance direction of the print medium, the reading unit can be reduced in size by moving the reading unit together with the printing unit. Thus, the configuration of the reading unit can be simplified and can be manufactured at low cost.
[0072]
  Claim6According to the above, since it is confirmed that there is no abnormality in the print unit immediately before each of the plurality of print images is printed, it is more effective that the print image printed on the print medium is deteriorated due to the abnormality of the print unit. Can be suppressed. In addition, when an abnormality occurs in the print unit, the print image on the print medium is printed before starting the printing of the next print image (at the end of printing of the print image being printed when an abnormality occurs in the print unit). Since printing is stopped, it is possible to effectively prevent the printing medium from being wasted due to misprinting.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of an ink jet printer according to a first embodiment.
FIG. 2 is a flowchart showing a procedure of a printing operation in the ink jet printer of FIG.
3 is a diagram for explaining a printing operation in the ink jet printer of FIG. 1. FIG.
[Explanation of symbols]
1 Inkjet printer
2 Paper (printing media)
5 Inkjet printing unit
6 Image reading unit
6a  Reading head (reading unit)
7  Cutting unit (cutting part)
8 Conveyance roller unit (conveyance means)
9 Pressure roller unit (conveying means)
10  Discharge roller unit (conveying means)
11 Print head (printing section)
15 Discharge nozzle
20 controller
21 Clogging detection unit (state detection means)
22 Control unit (control means)
50-53  Flushing image (confirmation image)
60-62  Image (printed image)

Claims (6)

Conveying means for conveying the print medium;
A plurality of ejection nozzles for ejecting ink to a print medium conveyed by the conveyance means, and a print image based on a confirmation image and print data formed by ejecting ink from the plurality of ejection nozzles. A printing unit for printing, a reading unit arranged on the downstream side of the printing unit for reading the surface of the print medium,
A state detecting unit for detecting the state of the printing unit based on data corresponding to the confirmation image read by the reading unit ;
A print image is printed so that image areas and non-image areas are alternately and continuously formed along the conveyance direction of the print medium, and a confirmation image is printed on at least one of the non-image areas. Control means for controlling the printing unit;
The printed print medium is arranged on the downstream side of the reading unit for cutting along the width direction of the print medium at a position substantially corresponding to the conveyance direction end of the print medium in the non-image area. An ink jet printer comprising a cutting unit . Control means for controlling the printing unit so that printing of a print image on a printing medium is started when the state detecting unit detects that the state of the printing unit is normal. 2. The ink jet printer according to claim 1 , wherein The control unit controls the printing unit to stop printing an image on a printing medium when the state detecting unit detects that the state of the printing unit is abnormal. Item 3. An ink jet printer according to Item 2 . The confirmation image is an ink jet according to any one of claims 1 to 3, characterized in that it is formed by the ink is ejected from all of said plurality of ejection nozzles by the flushing operation in the printing unit Printer. The reading unit, an ink jet printer according to any one of claims 1 to 4, characterized in that is provided so as to be close to the printing unit. In the case where a plurality of print images are continuously printed on a print medium, the control unit prints the confirmation image so that a confirmation image is always printed before printing of each print image is started. ink jet printer according to any one of claims 1 to 5, characterized in that for controlling the parts.

Images