JP2024125651A - Image recording device and control method thereof - Google Patents

Abstract

[Problem] During continuous printing in which multiple pages are printed in succession, even when print data control for the next page is performed in advance, mask non-discharge complement processing is correctly applied based on the latest non-discharge information. [Solution] An image recording device that ejects ink while scanning a recording medium with a recording head having an arranged group of ejection ports, and performs print data control based on image data of the image to be recorded and data on defective ejection ports among the ejection port groups, and uses an image recording device in which advanced print data control for a second page is performed while a first page is being printed, and before the second page is printed, the defective ejection ports used in the advanced print data control are compared with the latest data on defective ejection ports, and whether or not to redo print data control is determined based on whether there is a difference. [Selected Figure] Figure 14

Description

The present invention relates to an image recording device and a control method thereof.

Image recording devices equipped with a recording head having an ejection port array in which multiple ejection ports (nozzles) that eject ink are arranged are known. In such image recording devices, an image may be recorded by repeatedly performing a recording scan (main scan) in which the recording head is moved relatively to the recording medium in a first direction (e.g., X direction, intersecting direction) to eject ink, and a sub-scan in which the recording medium is transported in a second direction (e.g., Y direction, transport direction). In such image recording devices, a so-called multi-pass recording method is known in which an image is formed by performing multiple recording scans on the same area of the recording medium.

In this multi-pass printing method, a mask non-firing compensation process is known as a process to deal with the occurrence of one or more defective nozzles. For example, in the mask non-firing compensation process of Patent Document 1, the mask data for dividing the print data into multiple parts is rewritten, and the number of ink ejections is correctly compensated for by the normal nozzles that correspond to the defective nozzles.

JP 2000-094662 A

However, with the technology of Patent Document 1, during continuous printing in which multiple pages are printed in succession, if the print data control of the next page is advanced while the previous page is being printed in order to speed up throughput, mask non-discharge complement processing may not be applied correctly. The reason for this is that when the nozzle non-discharge state is updated after the print data control of the next page is advanced, an inconsistency occurs between the nozzle non-discharge state of the advanced print data control and the latest nozzle non-discharge state. In such cases, there are cases in which the mask non-discharge complement processing cannot be applied correctly. As a result, there is a risk of a decrease in image quality.

The present invention was made in consideration of the above problems, and aims to correctly apply mask non-firing compensation processing during continuous printing, in which multiple pages are printed in succession, even when print data control for the next page is performed in advance.

The present invention employs the following configuration.
An image recording apparatus that performs recording on a recording medium by moving a recording head relative to the recording medium and discharging ink onto the recording medium from discharge ports of the recording head,
a transport mechanism that moves the recording head and the recording medium relatively in a transport direction;
a moving mechanism for moving the recording head in a direction intersecting the transport direction;
A control unit;
Equipped with
the recording head has a plurality of ejection openings arranged in the transport direction, the plurality of ejection openings being divided into a plurality of ejection opening groups in the transport direction;
when the transport mechanism relatively moves the recording head and the recording medium in the transport direction, the transport mechanism moves the recording head and the recording medium a distance corresponding to a length of one of the plurality of ejection opening groups, so that the ink is ejected from the ejection openings included in the one ejection opening group to a unit area having a predetermined length in the transport direction of the recording medium during the movement of the recording head in the intersecting direction by the movement mechanism,
the transport mechanism sequentially performs the relative movement, thereby sequentially ejecting the ink from each of the ejection opening groups included in the plurality of ejection opening groups onto one of the unit areas,
The control unit is
performing print data control to select the ejection port that ejects when the recording head is moving in the intersecting direction, based on image data and defective ejection port information that indicates the positions of ejection-defective ejection ports among the plurality of ejection ports;
When performing continuous printing on a plurality of pages of the recording medium, while a first image is being recorded on a first page based on first image data, a preceding print data control is performed on a second page next to the first page based on second image data;
This image recording device is characterized in that before recording a second image based on the advance print data control for the second image data, second defective outlet information is obtained, and if there is a difference when comparing the first defective outlet information used in the advance print data control with the second defective outlet information, it is determined whether to cancel the advance print data control.

According to the present invention, during continuous printing in which multiple pages are printed in succession, even when print data control for the next page is performed in advance, mask non-firing compensation processing can be applied correctly.

FIG. 1 is a perspective view of an image recording apparatus according to an embodiment of the present invention; 1 is a cross-sectional view of an internal mechanism of an image recording apparatus according to an embodiment of the present invention; Schematic diagram of a recording head applied in the embodiment. FIG. 1 is a schematic diagram showing a printing control system according to an embodiment. A diagram for explaining a general multi-pass printing method. FIG. 1 is a diagram showing a process of processing a mask pattern and image data in an embodiment. FIG. 1 shows a decode table according to an embodiment. Schematic diagram for explaining degradation of image quality when ink ejection failure occurs FIG. 13 is a diagram for explaining the process of mask discharge failure complementation processing in the embodiment; FIG. 13 is a diagram for explaining the process of ejection failure complementation processing in the embodiment; FIG. 1 is a diagram for explaining a process of print data control in an embodiment. FIG. 1 is a diagram for explaining a cleaning control process in an embodiment. FIG. 13 is a diagram for explaining the process of change in ejection failure nozzle data in an embodiment; FIG. 1 is a diagram for explaining the process of a proposed method according to an embodiment.

The following describes in detail a preferred embodiment of the present invention with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention to those alone. Furthermore, the materials, shapes, etc. of components once described in the following explanations will remain the same in subsequent explanations as they were in the initial explanation, unless otherwise specified.

Fig. 1 is a perspective view partially showing the internal configuration of an inkjet type image recording apparatus 100 according to a first embodiment of the present invention, and Fig. 2 is a cross-sectional view partially showing the internal configuration of the image recording apparatus 100 according to the first embodiment of the present invention.

Inside the image recording device 100, a platen 2 is disposed, and a number of suction holes 34 are formed in the platen 2 to attract the recording medium 3 and prevent it from floating up. The suction holes 34 are connected to a duct 4, and a suction fan 36 is disposed below the duct 4. The suction fan 36 operates to attract the recording medium 3 to the platen 2.

The carriage 6 is supported by a main rail 5 that is installed extending in the paper width direction, and is configured to be able to move back and forth in the X direction (intersecting direction). The carriage 6 is equipped with an inkjet recording head 7, which will be described later. Note that various recording methods can be applied to the recording head 7, such as a thermal jet method using a heating element and a piezo method using a piezoelectric element. The carriage motor 8 is a drive source for moving the carriage 6 in the X direction, and the rotational drive force is transmitted to the carriage 6 by a belt 9. The main rail 5, carriage 6, and carriage motor 8 can be considered as a movement mechanism that moves the recording head in an intersecting direction that intersects the transport direction.

The recording medium 3 is fed by unwinding it from the medium 23 wound in a roll on the core 18. The recording medium 3 is transported in the Y direction (transport direction) that intersects with the X direction on the platen 2. The leading end of the recording medium 3 is sandwiched between the pinch roller 16 and the transport roller 11, and the transport is performed by driving the transport roller 11. In addition, the recording medium 3 is sandwiched between the roller 31 and the discharge roller 32 downstream of the platen 2 in the Y direction, and the recording medium 3 is further wound around the winding roller 24 via the turn roller 33. For convenience, the short direction of the recording medium 3 is called the paper width direction (X direction, cross direction), and the longitudinal direction that intersects with the paper width direction is called the transport direction (Y direction). The pinch roller 16 and the transport roller 11 can be considered as a transport mechanism that moves the recording medium 3 and the recording head 7 relatively in the transport direction. The transport mechanism can also be considered to further include the roller 31, the discharge roller 32, the turn roller 33, and the winding roller 24. The transport mechanism can also be considered to include a motor that provides driving force to those rollers.

Figure 3 shows the recording head 7 used in this embodiment. The recording head 7 has multiple ejection port rows 22, each of which corresponds to a different color. In this example, the ejection port rows 22 include yellow (Y), magenta (M), photomagenta (Pm), cyan (C), photocyan (Pc), black (K), gray (Gy), photogray (Pgy), red (R), and blue (B). There is also an ejection port row 22 that ejects a treatment liquid (P) for purposes other than coloring, such as protecting the recording surface and improving the uniformity of gloss. In this way, the recording head 7 has 11 ejection port rows 22 that can eject ink of each color, arranged in the X direction. These ejection port rows 22 are configured by 1280 ejection ports (hereinafter also referred to as nozzles) 30 that eject each ink, arranged in the Y direction (predetermined direction) at a density of 1200 dpi. Note that the ejection ports 30 adjacent to each other in the Y direction are arranged at positions shifted from each other in the X direction. In this embodiment, the amount of ink ejected from one ejection port 30 at one time is approximately 4.5 ng.

These nozzle arrays 22 are connected to ink tanks (not shown) that store the corresponding inks, and receive a supply of ink. Note that the recording head 7 and ink tanks used in this embodiment may be integrally configured, or may be separable from each other.

4 is a block diagram showing the schematic configuration of a control system in this embodiment. The main control unit 300 (control unit) includes a CPU 301 that executes processing operations such as calculation, selection, discrimination, and control, and a C
The main control unit 300 includes a ROM 302 that stores a control program to be executed by the PU 301. The main control unit 300 also includes a RAM 303 used as a buffer for print data, an input/output port 304, and the like. The memory 313 stores image data, which will be described later, and defective nozzle data (defective ejection port information). The input/output port 304 is connected to each of the drive circuits 305, 306, 307, and 308, such as a conveying motor 309 (LF motor), a carriage motor 310 (CR motor), the print head 7, and an actuator in a cutting device 314. The cutting device 314 is a cutting unit for cutting the print medium 3 to a desired length as necessary. The main control unit 300 is also connected to a host computer, a PC 312, via an interface circuit 311.

In this embodiment, an image is formed according to a multi-pass printing method that performs printing on a unit area on a printing medium using multiple scans (K times). The following explanation describes the case where a four-pass printing method is performed (K=4), which performs printing on a unit area using four scans.

Figure 5 is a diagram for explaining a general multi-pass printing method that is used when printing within a unit area on a printing medium using four printing scans. For simplicity, the following explanation will be given for a case in which an ejection port array 22 consisting of 16 ejection ports 30 is used, and ink is ejected from four ejection ports 30 into one unit area during each scan.

Each of the ejection ports 30 in the ejection port array 22 is divided (segmented) along the sub-scanning direction into four ejection port groups 201, 202, 203, and 204. In the first printing scan (one pass), ink is ejected from the ejection port group 201 onto a unit area 211 on the printing medium 3.

Next, the recording medium 3 is transported a distance of L/4 from the upstream side to the downstream side in the Y direction relative to the recording head 7. Note that for simplicity, the case where the recording head 7 is transported from the downstream side to the upstream side in the Y direction relative to the recording medium 3 is illustrated here, but the relative positional relationship between the recording medium 3 and the recording head 7 after transport is the same as when the recording medium 3 is transported downstream in the Y direction.

After this, a second printing scan is performed. During the second printing scan (two passes), ink is ejected from ejection port group 202 onto unit area 211 on the printing medium, and from ejection port group 201 onto unit area 212.

Then, the printing scan of the print head 7 and the relative transport of the print medium 3 are alternately repeated. As a result, after the fourth printing scan (four passes) has been performed, ink will have been ejected once from each of the ejection port groups 201 to 204 in the unit area 211 of the print medium 3.

Note that, although we have described the case where printing is performed on a unit area using four scans, printing can also be performed using a similar process when printing is performed using three or five or more scans.

(Recording data generation process)
In this embodiment, in a multi-pass printing method in which printing is performed on a unit area by K scans, there is image data in which information indicating the number of times of ejection from 0 to N (2≦N≦K) is defined for each pixel. K mask patterns in which information indicating the allowable number of times from 0 to M (2≦M≦K) is defined for each pixel are combined with the number of times of ejection indicated by the image data and the allowable number of times indicated by the mask patterns. Then, using a decode table that specifies whether to eject or not eject ink depending on the combination, 1-bit printing data used for printing in each scan is generated. The image data has a-bit information (a≧2) defined for each pixel, and the mask pattern has b-bit information (b≧2) defined for each pixel, but for simplicity, a case will be described here in which both the image data and the mask pattern are composed of 2-bit information.

Figure 6 is a diagram for explaining the process of generating print data using image data and a mask pattern, each of which has multiple bits of information. Also, Figure 7 is a diagram showing a decode table used when generating the print data shown in Figure 6.

Figure 6(a) is a diagram showing 16 pixels 700-715 in a unit area. For simplicity, the explanation will be given here using a unit area consisting of a pixel area equivalent to 16 pixels, but the number of pixel areas that make up the unit area can be set to a different value as appropriate.

Figure 6(b) is a diagram showing an example of image data corresponding to a unit area. Here, image data having a-bit information can reproduce a maximum of 2^a numbers of ink ejections. As the image data here is composed of 2-bit information as described above, a maximum of 4 (=2^2) numbers of ink ejections, which is 2 to the power of 2, can be expressed. In this diagram, the number of ejections is shown in binary, with four possibilities ranging from "00" to "11" (i.e. 0 to 3 in decimal).

In addition, in this embodiment, the maximum number of ink ejections reproduced using image data having a-bit information is (2^a)-1 times. Since a=2 in this embodiment, the maximum number of ink ejections represented is 3 (=(2^2)-1), which is the value obtained by subtracting 1 from the square of 2.

Specifically, when the value indicated by the 2-bit information constituting the image data corresponding to a pixel (hereinafter also referred to as the pixel value) is "00", no ink is ejected onto that pixel. When the pixel value is "01", ink is ejected onto the corresponding pixel once. When the pixel value is "10", ink is ejected onto the corresponding pixel twice. When the pixel value is "11", ink is ejected onto the corresponding pixel three times. In this way, the image data in this embodiment is set to eject any number of times from 0 to 3 for each pixel (N=3).

For the image data shown in FIG. 6(b), for example, the pixel values of pixels 703, 704, 709, and 712 are "00", so ink is not ejected even once into the pixel areas corresponding to pixels 703, 704, 709, and 712. Also, for example, the pixel values of pixels 702, 706, 707, and 715 are "11", so ink is ejected three times into the pixel areas corresponding to pixels 702, 706, 707, and 715.

Figures 6(c-1) to 6(c-4) correspond to the first to fourth scans, respectively, and are figures showing mask patterns to be applied to the image data shown in Figure 6(b). That is, by applying mask pattern 505 corresponding to the first scan shown in Figure 6(c-1) to the image data shown in Figure 6(b), print data to be used in the first scan is generated. Similarly, by applying mask patterns 506, 507, and 508 shown in Figures 6(c-2), 6(c-3), and 6(c-4), respectively, to the image data shown in Figure 6(b), print data to be used in the second, third, and fourth scans, respectively, is generated.

Here, each pixel in the mask patterns shown in Figures 6(c-1) to 6(c-4) is assigned one of four (=2^b) values, "00", "01", "10", and "11", as the value indicated by the 2-bit information (hereinafter also referred to as the code value).

As can be seen by referring to the decode table shown in FIG.
In this case, no ink is ejected regardless of whether the pixel value of the corresponding pixel is "00,""01,""10," or "11." In other words, a code value of "00" in the mask pattern corresponds to no ink ejection being permitted (the permitted number of times ink is ejected is 0). In the following explanation, pixels in the mask pattern to which a code value of "00" is assigned are also referred to as non-printing permitted pixels.

On the other hand, as can be seen by referring to the decode table shown in FIG. 7, when the code value is "01", ink is not ejected if the pixel value of the corresponding pixel is "00", "01", or "10", but ink is ejected if the pixel value is "11". In other words, a code value of "01" corresponds to allowing ink to be ejected only once for each of the four pixel values ("00", "01", "10", and "11") (the number of times ink is ejected is allowed to be once).

In addition, when the code value is "10", ink is not ejected if the pixel value of the corresponding pixel is "00" or "01", but ink is ejected if the pixel value is "10" or "11". In other words, a code value of "10" corresponds to allowing ink to be ejected twice for four different pixel values (the allowed number of times ink is ejected is two).

Furthermore, when the code value is "11", ink is not ejected if the pixel value of the corresponding pixel is "00", but ink is ejected if the pixel value is "01", "10", or "11". In other words, the code value of "11" corresponds to allowing ink to be ejected three times for four different pixel values (the allowed number of times ink is ejected is three). In the following explanation, pixels in the mask pattern that are assigned one of the three (=2^b-1) code values of "01", "10", or "11" are also referred to as print-allowed pixels.

Thus, in the mask pattern of this embodiment, the allowable number of times for each pixel is set to be between 0 and 3 (M=3).

The mask pattern having multiple bits of information used in the four-pass printing method of this embodiment is set based on the following (Condition 1) and (Condition 2).

(Condition 1)
Here, (2^b)-1 print permitting pixels are set to be arranged in multiple pixels at the same position in multiple mask patterns. These (2^b)-1 print permitting pixels permit different numbers of ink to be ejected. In this embodiment, since b=2, one of the code values "01", "10", or "11" is assigned to each of three of the four pixels at the same position in the four mask patterns shown in Figures 6(c-1) to 6(c-4) (print permitting pixel). The remaining one (=4-3) pixel is assigned a code value of "00" (non-print permitting pixel).

For example, pixel 700 is assigned a code value of "01" in the mask pattern shown in FIG. 6(c-3), a code value of "10" in the mask pattern shown in FIG. 6(c-2), and a code value of "11" in the mask pattern shown in FIG. 6(c-1). The remaining mask pattern shown in FIG. 6(c-4) assigns a code value of "00." In other words, pixel 700 is a print-permitted pixel in the mask patterns shown in FIG. 6(c-1), FIG. 6(c-2), and FIG. 6(c-3), and is a non-print-permitted pixel in the mask pattern shown in FIG. 6(c-4).

Furthermore, pixel 701 is assigned a code value of "01" in the mask pattern shown in Fig. 6(c-2), "10" in the mask pattern shown in Fig. 6(c-1), and "11" in the mask pattern shown in Fig. 6(c-4). In addition, pixel 701 is assigned a code value of "00" in the remaining mask pattern shown in Fig. 6(c-3). In other words, pixel 701 is a print permitted pixel in the mask patterns shown in Fig. 6(c-1), 6(c-2), and 6(c-4), and is a print non-permitted pixel in the mask pattern shown in Fig. 6(c-3).

With this configuration, even if the pixel value of a pixel is "00," "01," "10," or "11," it is possible to generate print data that ejects ink into the pixel area corresponding to that pixel the number of times that corresponds to that pixel value.

(Condition 2)
In addition, the mask patterns shown in each of Fig. 6(c-1) to Fig. 6(c-4) are arranged so that the number of print permitting pixels corresponding to the code value of "01" is approximately the same. More specifically, in the mask pattern shown in Fig. 6(c-1), the code value of "01" is assigned to four pixels, i.e., pixels 702, 707, 708, and 713. In the mask pattern shown in Fig. 6(c-2), the code value of "01" is assigned to four pixels, i.e., pixels 701, 706, 711, and 712. In the mask pattern shown in Fig. 6(c-3), the code value of "01" is assigned to four pixels, i.e., pixels 700, 705, 710, and 715. In the mask pattern shown in Fig. 6(c-4), the code value of "01" is assigned to four pixels, i.e., pixels 703, 704, 709, and 714. That is, in each of the four mask patterns shown in FIG. 6(c-1) to FIG. 6(c-4), four print permitting pixels corresponding to a code value of "01" are arranged.

Similarly, in the mask patterns shown in each of Figures 6(c-1) to 6(c-4), the print permitting pixels corresponding to a code value of "10" are arranged in equal numbers. Furthermore, in the mask patterns shown in each of Figures 6(c-1) to 6(c-4), the print permitting pixels corresponding to a code value of "11" are arranged in equal numbers.

Note that, although we have described a case in which the same number of print-permitting pixels are arranged for each code value "01", "10", and "11" in each mask pattern, in reality it is sufficient if approximately the same number of print-permitting pixels are arranged.

As a result, when image data is distributed to four scans to generate print data using the mask patterns shown in Figures 6(c-1) to 6(c-4), the print rates in each of the four scans can be made approximately equal.

Figures 6(d-1) to 6(d-4) each show print data generated by applying the mask patterns shown in Figures 6(c-1) to 6(c-4) to the image data shown in Figure 6(b). In the print data, printing (ejection) is indicated by "1" and not printing (non-ejection) is indicated by "0".

For example, the pixel value of the image data for pixel 700 is "10", and the code value of the mask pattern corresponding to the first scan is "11". Therefore, by referring to the decode table shown in FIG. 7, the print data corresponding to the first scan shown in FIG. 6(d-1) defines ink ejection ("1") for pixel 700. Also, the pixel value of the image data for pixel 701 is "01", and the code value of the mask pattern corresponding to the first scan is "10", so the print data corresponding to the first scan shown in FIG. 6(d-1) defines no ink ejection ("0") for pixel 701. Also, the pixel value of the image data for pixel 714 is "10", and the code value of the mask pattern corresponding to the first scan is "00", so the print data corresponding to the first scan shown in FIG. 6(d-1) defines no ink ejection ("0") for pixel 704.

Ink is ejected in the first to fourth scans according to the print data thus generated and shown in Figures 6(d-1) to 6(d-4). For example, in the first scan, as can be seen from the print data shown in Figure 6(d-1), ink is ejected onto pixel areas on the print medium that correspond to pixels 700, 702, 705, 706, 707, 710, and 715.

Figure 6(e) is a diagram showing the logical sum of the recording data shown in each of Figures 6(d-1) to 6(d-4). By ejecting ink according to the recording data shown in each of Figures 6(d-1) to 6(d-4), ink is ejected into the pixel area corresponding to each pixel the number of times shown in Figure 6(e).

For example, for pixel 700, the ejection of ink is determined in the print data corresponding to the first and second scans shown in Figures 6(d-1) and 6(d-2). Therefore, as shown in Figure 6(e), ink is ejected a total of two times onto the pixel area corresponding to pixel 700. Also, for pixel 701, the ejection of ink is determined in the print data corresponding to the fourth scan shown in Figure 6(d-4). Therefore, as shown in Figure 6(e), ink is ejected a total of once onto the pixel area corresponding to pixel 701.

Comparing the print data shown in FIG. 6(e) with the image data shown in FIG. 6(b), it can be seen that the print data is generated so that for each pixel, ink is ejected the number of times that corresponds to the pixel value of the image data. For example, for pixels 702, 706, 707, and 715, the pixel value of the image data shown in FIG. 6(b) is "11 (binary number)," and the number of ink ejections indicated by the logical sum of the generated print data is "3 (decimal number)," so the two match.

The above configuration makes it possible to generate 1-bit print data to be used in each of multiple scans based on image data having multiple bits of information and a mask pattern.

(Ink ejection failure)
The degradation of image quality when defective ink ejection occurs in multiple ejection ports capable of ejecting ink onto the same pixel region when using image data and mask patterns having the above-mentioned multiple-bit information will be described in detail below.

Figure 8 (a) is a diagram for explaining the effect on the image quality of the image recorded in the unit area 211 when defective ink ejection occurs in ejection outlet 30a and ejection outlet 30d, which are capable of ejecting ink into area 211a (partial area) out of the 16 ejection outlets 30. For simplicity, in the following explanation, an ejection outlet where defective ink ejection has occurred will be referred to as a defective ejection nozzle (defective ejection outlet), and an ejection outlet where no defective ink ejection has occurred will be referred to as a normal ejection nozzle (normal ejection outlet).

Normally, ink can be ejected into area 211a a total of four times from each of ejection ports 30a to 30d during each of the first to fourth scans. However, if ejection port 30a and 30d are defective nozzles, ink cannot be ejected into area 211a during the first and fourth scans, even if the print data is set so that ink is ejected from ejection ports 30a and 30d. Although ink can be ejected into area 211a from ejection ports 30b and 30c, which are normal ejection nozzles, because ejection ports 30a and 30d are defective nozzles, the maximum number of times ink is ejected into area 211a is two. This raises the risk that the desired number of ejections into area 211a will not be obtained.

FIG. 8B is a diagram for explaining the degradation of image quality that occurs when ejection ports 30a and 30d that are ejection-defective nozzles as shown in FIG. 8A occur.

When the image data and mask pattern shown in FIG. 6 are used, as can be seen from FIG. 6 (d-1), the print data corresponding to the first scan specifies that ink will be ejected ("1") to pixels 705, 706, and 707 in area 211a. However, because area 211a corresponds to ejection port 30a, which is a nozzle that is defective in the first scan, ink cannot actually be ejected even though the print data specifies that ink will be ejected. Therefore, ink will not be ejected to the pixel area corresponding to pixels 705, 706, and 707 in the first scan.

Similarly, as can be seen from FIG. 6 (d-4), the print data corresponding to the fourth scan specifies that ink will be ejected ("1") to pixels 706 and 707 in region 211a. However, since region 211a corresponds to ejection port 30d, which is a nozzle that is defective in the fourth scan, ink cannot actually be ejected into the pixel region corresponding to pixels 706 and 707 in the fourth scan.

Here, as can be seen from FIG. 8(b), the pixel regions (partial regions extending in the X direction) corresponding to pixels 700-703 and 708-715 in unit region 211 do not face ejection ports 30a and 30d, which are defective nozzles, in each scan. Therefore, ink can be ejected the same number of times as the ideal number of ink ejections shown in FIG. 6(e). Also, the pixel region corresponding to pixel 704 faces ejection port 30a, which is the defective nozzle, in the first and fourth scans. However, as shown in FIG. 6(d-1) and FIG. 6(d-4), non-ejection of ink ("0") is defined in the print data corresponding to the first and fourth scans, so the number of ink ejections is the same as the ideal number of ink ejections shown in FIG. 6(e).

On the other hand, in the pixel area corresponding to pixel 705 in unit area 211, ink is not ejected even once in total, whereas the ideal number of times ink is ejected is once as shown in FIG. 6(e). This is because, as described above, ink is not ejected in the pixel area corresponding to pixel 705 during the first scan, resulting in a deviation from the ideal number of times ink is ejected.

Also, for pixel 706 in unit area 211, ink is ejected a total of only once, whereas the ideal number of times for ejecting ink is three, as shown in FIG. 6(e). This is because, although ink is ejected into the pixel area corresponding to pixel 706 in accordance with the print data shown in FIG. 6(d-2) during the second scan, ink is not ejected during the first and fourth scans.

Furthermore, even for pixel 707 in unit area 211, ink is ejected a total of only once, whereas the ideal number of times of ink ejection shown in FIG. 6(e) is three. This is because, although ink is ejected into the pixel area corresponding to pixel 707 in accordance with the print data shown in FIG. 6(d-3) during the third scan, ink is not ejected during the first and fourth scans.

As described above, if poor ink ejection occurs, there is a risk that the actual number of ink ejections will differ from the ideal number of ink ejections, resulting in a deterioration in the quality of the resulting image.

(Mask non-discharge complement processing)
In consideration of the above, in this embodiment, when poor ink ejection occurs, a process is executed in which the ink that should have been ejected from the defective nozzle is compensated for and ejected by other normal ejection nozzles (hereinafter referred to as mask non-ejection complement process or mask complement process).

Here, the mask non-ejection complement process is a process that modifies the code values in the mask pattern. In detail, it is a process that assigns the code value of a complement source pixel, which is a pixel in the mask pattern that corresponds to a non-ejection nozzle, to a complement destination pixel, which is a pixel in the mask pattern that corresponds to a normal-ejection nozzle that can eject ink into the same pixel region as the non-ejection nozzle.

This mask non-discharge complement process is described in detail below. Figure 9 is a flowchart of the mask non-discharge complement process executed by the control program in this embodiment. Note that each process shown in Figure 9 is realized, for example, by the CPU 301 reading the control program stored in the ROM 302 into the RAM 303 and executing it.

First, in step S11 shown in FIG. 9, the number of ejections for each pixel region in the unit region 211 is obtained based on the pixel value of each pixel indicated by the image data. For example, if the pixel value of a pixel is "00", the number of ejections for the pixel region corresponding to that pixel obtained in step S11 is "0". Also, if the pixel value of a pixel is "10", the number of ejections for the pixel region corresponding to that pixel obtained in step S11 is "2".

Next, in step S12, the non-ejecting nozzle data stored in memory 313 is read out, and the number of normally ejecting nozzles, which indicates how many times normally ejecting nozzles correspond to each pixel area over multiple scans, is obtained for each pixel.

For example, in a system in which printing is performed on a unit area such as that shown in FIG. 5 by four scans, if a certain pixel area is associated with a normally-ejecting nozzle in all four scans, the number of normally-ejecting nozzles associated with that pixel area obtained in step S12 will be "4". Also, if a certain pixel area is associated with a normally-ejecting nozzle in one scan and with a faulty ejection nozzle in three scans, the number of normally-ejecting nozzles associated with that pixel area obtained in step S12 will be "1".

The faulty nozzle data used in step S12 can be generated by various methods. For example, a test pattern can be recorded so that ink is ejected from all ejection ports before the mask non-ejection complementation process is executed, and the faulty nozzle data obtained by identifying the faulty nozzles based on the test pattern can be used. In addition, the position and number of faulty nozzles may change as the inkjet image recording device 100 is used. In order to keep up with such changes, the faulty nozzle data may be updated based on information detected during a recovery operation or a preliminary ejection operation at the home position of the recording head 111, for example.

Next, in step S13, it is determined whether the number of normally ejecting nozzles obtained in step S12 for each pixel region is greater than the number of ejections obtained in step S11. For pixels corresponding to pixel regions where it is determined that the number of normally ejecting nozzles is greater than the number of ejections, a mask non-ejection complement process is executed in step S14 to modify the code value of the mask pattern for that pixel region.

Figure 10 is a flowchart corresponding to a detailed subroutine of the mask non-discharge complement process executed in step S14 by the control program in this embodiment. Note that each process shown in Figure 10 is realized, for example, by the CPU 301 reading the control program stored in the ROM 302 into the RAM 303 and executing it.

In step S301, the defective nozzle data stored in the memory 313 is read out.
Information for identifying the nozzle that has the ink ejection failure is obtained. The ejection failure nozzle data used here may be the same as that used in step S11.

In step S302, a complementary pixel group is selected. Here, a pixel group consisting of multiple pixels that are in the same position in multiple mask patterns is assumed. Then, one of the complementary pixel groups that includes at least one pixel corresponding to the discharge-failed nozzle is selected as the pixel group that will first perform the mask non-discharge complementation process. Note that if there are multiple complementary pixel groups, the order in which the mask non-discharge complementation process is performed can be set appropriately. For example, in step S302, one complementary pixel group that will perform the mask non-discharge complementation process may be selected randomly from the multiple complementary pixel groups.

Next, in step S303, the code value of the complement source candidate pixel (first candidate pixel) corresponding to the non-discharge nozzle is obtained from the complement pixel group selected in step S302. At this time, if there is only one complement source candidate pixel corresponding to the non-discharge nozzle from the complement pixel group selected in step S302, one code value is obtained. Also, if there are multiple complement source candidate pixels corresponding to the non-discharge nozzle, the code value of each complement source candidate pixel is obtained.

Next, in step S304, one code value is selected from the code values of the candidate pixels obtained in step S303 as code value A of the pixel to be complemented (first pixel) to be used in the process described below. If multiple code values were obtained in step S303, then in step S304, the code value indicating the greatest number of permitted ink ejections is selected from the code values of the candidate pixels to be complemented obtained in step S303. This is set as the code value A of the pixel to be complemented.

As described above using the decode table shown in FIG. 7, in this embodiment, when the code value is "00", ink is not ejected even if the pixel value of the corresponding pixel is "00", "01", "10", or "11". In other words, the code value "00" indicates that the number of times ink is allowed to be ejected is 0. Also, when the code value is "01", ink is ejected only when the corresponding pixel value is "11". That is, the code value "01" indicates that the number of times ink is allowed to be ejected is 1. Similarly, the code value "10" indicates that the number of times ink is allowed to be ejected is 2, and the code value "11" indicates that the number of times ink is allowed to be ejected is 3. Therefore, the code values of the mask pattern in this embodiment are "00", "01", "10", and "11" in order of the number of times ink is allowed to be ejected, starting from the number of times the ink is allowed to be ejected.

Therefore, for example, if the code values of the candidate pixels obtained in step S303 are "00" and "11", the code value of "11" is selected as the code value A of the candidate pixels in step S304. Also, for example, if the code values of the candidate pixels obtained in step S703 are "00", "01", and "10", the code value of "10" is selected as the code value A of the candidate pixels in step S304. Also, for example, if the code value of the candidate pixels obtained in step S303 is only "01", the code value of "01" is selected as the code value A of the candidate pixels in step S304.

Next, in step S305, the code value of the candidate complement pixel (second candidate pixel) corresponding to the normally ejecting nozzle is obtained from the group of complement pixels selected in step S302. At this time, if there is only one candidate complement pixel corresponding to the normally ejecting nozzle from the group of complement pixels selected in step S302, one code value is obtained. Also, if there are multiple candidate complement pixels corresponding to the normally ejecting nozzle, the code value of each candidate complement pixel is obtained.

Next, in step S306, one code value is selected from the code values of the candidate complement pixels acquired in step S305 as code value B of the complement pixel (second pixel) described below. Here, in step S304 in this embodiment, the code value that indicates the smallest number of permitted ink ejections is selected from the code values of the candidate complement pixels acquired in step S305, and is set as code value B of the complement pixel.

For example, if the code values of the candidate complement pixels acquired in step S305 are "00" and "11", the code value of "00" is selected as the code value B of the complement pixel in step S306. Also, if the code values of the candidate complement pixels acquired in step S705 are "01", "10", and "11", the code value of "01" is selected as the code value B of the complement pixel in step S306. Also, if the code value of the candidate complement pixels acquired in step S305 is only "10", the code value of "10" is selected as the code value B of the complement pixel in step S306.

Next, in step S307, the code value A selected in step S304 is compared with the code value B selected in step S706. If the allowable number of ink ejections indicated by code value A is greater than the allowable number of ink ejections indicated by code value B, the process proceeds to step S308, where the code value B defined for the complement pixel is replaced with the code value A defined for the complement source pixel. On the other hand, if the allowable number of ink ejections indicated by code value A is less than the allowable number of ink ejections indicated by code value B, the replacement process is not executed.

For example, suppose that the code value A selected in step S304 is "11" and the code value B selected in step S306 is "00". In this case, the allowable number of times indicated by code value A (3 times) is greater than the allowable number of times indicated by code value B (0 times), so in step S308, the code value B of "00" of the destination pixel is replaced with the code value of "11" of the source pixel. Also, if code value A is "10" and code value B is "01", the allowable number of times indicated by code value A (2 times) is greater than the allowable number of times indicated by code value B (1 time), so the code value B of "01" of the destination pixel is replaced with the code value of "10" of the source pixel. Also, if code value A is "01" and code value B is "11," the allowable number of times indicated by code value A (1 time) is less than the allowable number of times indicated by code value B (3 times), so replacement processing is not performed and the code value of the complemented pixel remains unchanged at the original "11."

Next, in step S309, it is determined whether or not there are any candidate pixels for complementation among the group of complement pixels selected in step S302 for which the processes in steps S304 to S308 have not been performed. If it is determined that the processes in steps S304 to S308 have been performed for all candidate pixels for complementation, the process proceeds to step S310.

On the other hand, if it is determined that there are remaining candidate complement pixels for which the processes in steps S304 to S308 have not been performed, the process returns to step S304, and the same processes as those in steps S304 to S308 are performed on the remaining candidate complement pixels. Here, in this embodiment, any complement destination pixel that has been replaced at least once in step S308 within one complement pixel group is excluded from the candidate complement destination pixels in step S305 in the subsequent processes.

Then, in step S310, it is determined whether or not the processes in steps S303 to S309 have been performed on all of the complement pixel groups that include at least one pixel corresponding to the discharge-failed nozzle. If it is determined that there are any complement pixel groups that have not been subjected to the processes in steps S303 to S309, the process returns to S302, and the processes in steps S303 to S309 are performed on the remaining complement pixel groups. On the other hand, if it is determined that the processes in steps S303 to S309 have been performed on all of the complement pixel groups, the mask discharge failure complement process is terminated, and the finally obtained mask pattern is updated as the mask pattern to be used for generating print data.

The above configuration enables the ejection-failed nozzle to effectively compensate for the lack of ejection frequency at the corresponding pixel. However, it has been found that there are cases in which the mask ejection failure compensation process cannot be applied correctly.

(Inter-page advance processing)
During inter-page advance processing, there is a possibility that the mask non-discharge complement processing cannot be performed correctly. Inter-page advance processing is processing in which, when the image recording device prints multiple pages continuously, print data control of the image data of the x+1th sheet is started in advance during print control of the xth sheet. Note that, in the case of cut paper, a page refers to a unit of an image that is printed in parts on multiple sheets of paper, and in the case of roll paper, it refers to a unit of an image that is printed page by page and then cut. Furthermore, a page does not necessarily have to be a unit that is physically cut before or after printing, but may be a unit that performs print data control collectively.

Print control refers to the mechanical control that operates the recording head in the X direction relative to the recording medium, ejects ink from the nozzles of the recording head, and operates the LF motor, CR motor, and recording head to transport the recording medium from the upstream side to the downstream side in the Y direction relative to the recording head.

Print data control refers to data control that stores image data and mask patterns in RAM based on a control program recorded in ROM by the CPU of the image recording device. It also refers to data control that issues operating commands to mechanical control units such as the LF motor, CR motor, and recording head at appropriate timing. In other words, printing control is performed based on print data control, and mechanisms such as the LF motor, CR motor, and recording head operate.

Figure 11 is a flowchart of print data control in this embodiment. Note that each process shown in Figure 11 is realized, for example, by the CPU 301 reading a control program stored in the ROM 302 into the RAM 303 and executing it.

First, in step S701 shown in FIG. 11, the image recording device 100 receives image data sent from the PC.

Next, in step S702, the received image data is divided into band data of a specific length. Note that the band data is assumed to be a fixed size across the page.

Next, in step S703, the divided band data is converted from the top into data of ink colors that the printer can recognize. The ink colors that the printer can recognize are, for example, yellow (Y), magenta (M), photo magenta (Pm), cyan (C), photo cyan (Pc), black (K), gray (Gy), photo gray (Pgy), red (R), and blue (B). Also, assume that the ink colors are processing liquids (P) that have purposes other than coloring, such as protecting the recording surface or improving gloss uniformity.

Next, in step S704, the ink color data is converted into image data having a-bit information and stored in the print buffer. Here, the image data having a-bit information can reproduce up to 2^a different numbers of ink ejections.

Next, in step S705, appropriate data having multiple bits of information for the mask pattern as well as the image data is stored in the mask buffer. A method for generating a mask pattern having multiple bits of information is set based on (Condition 1) and (Condition 2) of (Print data generation process).

Next, in step S706, the defective nozzle data stored in the memory is read out, and a mask non-discharge complement process is performed that involves modifying the code values of the mask pattern. Note that the defective nozzle data can be generated by various methods. For example, a test pattern can be recorded before printing so that ink is discharged from all nozzles, and the defective nozzle can be identified based on the test pattern. Also, as the image recording device 100 is used, the defective nozzle data may be updated. In order to follow such fluctuations, for example, light may be irradiated onto ink discharged by a preliminary discharge operation or the like at the home position of the recording head 7, and the defective nozzle data may be updated based on the reflected light. Note that the defective nozzle data can be used to determine non-discharge on a nozzle-by-nozzle basis. (Hereinafter referred to as non-discharge detection process).

Next, in step S707, a one-line print command is issued to the mechanical control unit that controls the LF motor, CR motor, and print head. The one-line print command contains various information required for print control, such as the CR speed, print direction, LF length, and the buffer storage destination for image data and mask data. The print control unit performs print control based on the one-line print command.

Finally, in step S708, it is determined whether all band data has been processed. If so, the process ends. If not, the process proceeds to step S702, where processing of the next band data begins.

Image recording devices record images by repeating print data control and print control. Therefore, if print data control is delayed, a delay will occur in print control, causing the recording scan to stop momentarily, which may affect throughput.

To prevent such cases, when an image recording device prints multiple pages consecutively, the purpose of inter-page advance processing is to speed up throughput by initiating print data control of the image data for the x+1th page in advance while printing control of the xth page is in progress.

Next, we will explain the cases where mask non-ejection compensation processing cannot be applied correctly due to inconsistencies in the non-ejection nozzle data when performing inter-page advance processing.

There are cases where nozzle cleaning is performed after printing is completed. Figure 12 is a flowchart showing the conditions for starting cleaning in this embodiment. Note that each process shown in Figure 12 is realized, for example, by the CPU 301 reading a control program stored in the ROM 302 into the RAM 303 and executing it.

First, in step S801 shown in FIG. 12, it is confirmed whether the cumulative number of ink discharges (hereinafter also referred to as dot count) from each nozzle exceeds the cleaning threshold. If it does exceed the threshold, the process proceeds to step S802. If it does not exceed the threshold, control ends without cleaning the nozzles. Note that the cleaning threshold is a value that exceeds the threshold when 200 solid images are printed on an A1-sized recording medium, for example.

In step S802, the nozzles are cleaned after printing is completed. Note that cleaning refers to, for example, removing ink blockages from the nozzles by sucking the ink out. Ink stains on the ink ejection openings may also be removed using a wiper.

Next, in step S803, a non-discharge detection process is performed, and the defective nozzle data stored in the memory of the image recording device is updated. This is because the state of the nozzle may change due to cleaning and previous printing. Specifically, there may be cases where a nozzle that is normally discharged changes to a defective nozzle, and cases where a defective nozzle changes to a normal nozzle.

Finally, in step S804, the dot count of the nozzle that exceeded the threshold is reset to 0 and control ends.

When printing consecutive pages, if inter-page advance processing is enabled and cleaning and misfiring detection processing are inserted between pages, print data control for the next page will begin in advance before cleaning is performed. However, there are cases where the misfiring detection processing updates the non-ejecting nozzle data after cleaning.

As a result, there may be a difference between the faulty nozzle data used by the preceding print data control and the faulty nozzle data updated after cleaning. This difference may prevent the mask non-firing compensation process from being applied correctly, resulting in a decrease in image quality. This is explained in detail below.

First, Figure 13(a) shows the state of a nozzle of a certain color before and after cleaning. For simplicity, let's assume that there are 16 nozzles here. Before cleaning, the seventh nozzle from the top (N7) was a defective nozzle, but after cleaning, it has changed to a normal nozzle. In this case, print data control is started in advance according to the state of the nozzle before cleaning, so mask non-discharge complement processing is performed on the assumption that the seventh nozzle from the top is a defective nozzle. On the other hand, because cleaning is performed after printing is completed, the defective nozzle has changed to a normal nozzle, so according to the state of the nozzle after cleaning, there is no need to perform mask non-discharge complement processing. However, print data control has already started in advance according to the nozzle state before cleaning, so mask non-discharge complement processing is performed before printing.

In the case of FIG. 13(a), the number of ink ejections remains the same as the original number of ejections due to the mask non-ejection compensation process, so although the printing method is different from that expected, it is thought that the impact on image quality is not significant.

Next, in Figure 13(b), all nozzles were normal ejection nozzles before cleaning, but after cleaning, the 10th nozzle (N10) and 13th nozzle (N13) from the top have become defective ejection nozzles. Such changes may occur depending on the cleaning conditions. Also, such changes may occur due to phenomena other than cleaning.

In this case, print data control starts first according to the state of the nozzles before cleaning, so mask non-discharge compensation processing is not performed on the assumption that all nozzles are normally ejecting. However, because cleaning is performed after printing is completed, the normally ejecting nozzles have become defective nozzles, so mask non-discharge compensation processing is actually necessary. However, because print data control has already started at that point, printing will proceed without performing mask non-discharge compensation processing.

In the case of FIG. 13(b), the number of ink ejections is less than the normal number of ejections, which is a printing method different from that expected, and because the number of ejections is also small, a deterioration in image quality is unavoidable. In particular, the deterioration in image quality is thought to be more noticeable in low-pass printing methods that have a relatively small number of passes.

As a result of the above, when a nozzle that is not properly ejecting changes to a nozzle that is not properly ejecting, there is little impact on image quality even if inter-page advance processing is enabled. On the other hand, when a nozzle that is properly ejecting changes to a nozzle that is not properly ejecting, it leads to a deterioration in image quality.

(Method of correctly applying mask non-ejection compensation processing even when performing inter-page advance processing)
14 is a flowchart showing a method for correctly applying the mask non-ejection complement process even when the inter-page advance process is being performed in this embodiment. Note that each process shown in FIG. 14 is realized, for example, by the CPU 301 reading out a control program stored in the ROM 302 into the RAM 303 and executing it.

First, in step S901, the print process for the xth page ends. If inter-page advance processing is enabled, print data control for the x+1th page begins in advance at this point.

Next, in step S902, cleaning control is performed. If the dot count for each nozzle exceeds the cleaning threshold, cleaning is performed, and then non-ejection detection processing is performed to update the non-ejection nozzle data.

Next, in step S903, the non-ejecting nozzle data after the non-ejection detection process is compared with the previous non-ejecting nozzle data. The difference between the previous and latest faulty nozzle data is then confirmed to determine whether or not there has been a change from a normally ejecting nozzle to a faulty nozzle. If the comparison shows that there is no difference, or there is a difference but the faulty nozzle has changed to a normally ejecting nozzle, throughput is prioritized and printing continues based on the previous print data control. If there is a difference and the normally ejecting nozzle has changed to a faulty nozzle, image quality is prioritized and the process proceeds to step S904.

In step S904, the print data control currently in progress is cancelled, and in step S905, the print data control is restarted from the beginning. At this time, the image data received by the image recording device may be reused. Also, it is acceptable to restart only the mask non-firing compensation process in the print data control.

With the above configuration, only under conditions where the mask non-firing compensation process cannot be applied correctly and there is a risk of a deterioration in image quality, the previous print data control is redone and the print data control is redone using the latest defective nozzle data, making it possible to improve image quality.

Second Embodiment
In the first embodiment, in step S903 in Fig. 14, the non-ejecting nozzle data after the non-ejection detection process is compared with the previous non-ejecting nozzle data, and if there is a difference but the ejection-failed nozzle has changed to an ejection-normal nozzle, nothing is done. In this embodiment, the preceding print data control is redone in certain cases. This will be described in detail below.

When nozzles 30a, 30d that are defective as shown in FIG. 8 occur, region 211a becomes a pixel group corresponding to nozzles 30a, 30d that are defective. When multiple nozzles that are defective are assigned to the same pixel in this way, the mask non-firing compensation process may not be able to compensate for the lack of discharges. In such a case, if at least one of nozzles 30a, 30d that are defective nozzles can be changed to a normal nozzle by cleaning, the lack of discharges can be compensated for. In such a case, by redoing print data control based on the change from a defective nozzle to a normal nozzle, it is possible to improve image quality compared to using the results of the preceding print data control as is.

Therefore, in the multi-pass printing method, if multiple nozzles with poor ejection performance are assigned to the same pixel, if one or both of the nozzles with poor ejection performance change to normal ejection performance after cleaning, the previous print data control is redone.

(Modification)
Also, even if the conditions for redoing the preceding print data control are met, if the print data is printed in a throughput-prioritized print mode, there may be cases where the print data is not redoed because throughput takes precedence over image quality.Whether the print mode is throughput-prioritized may be based on, for example, a user's specification using the PC 312, or information indicating the print mode may be included in the image data.The print mode is stored in, for example, the memory 313 or the RAM 303, and is used to determine whether to redo the print data control.

Third Embodiment
In the first embodiment, printing in a 4-pass recording method has been described. In the case of a low pass such as a 1-3 pass recording method, the print quality is lowered but the print speed is increased. In this way, when using a low pass recording method, there are many cases where the purpose is to prioritize print speed over image quality, so the effect of correctly applying the mask non-discharge complement process is not high. Therefore, when printing in a low pass recording method such as 1-3 passes, even if the discharge failure nozzle data is updated during the inter-page advance process, there may be cases where the throughput is prioritized and the preceding print data process is not repeated. Note that the distinction between low pass and high pass is determined according to conditions such as the performance of the image recording device, the type of recording medium, and the desired image quality desired by the user, and is not limited to the above example.

As described above, according to each embodiment of the present invention, during continuous printing in which multiple pages are printed in succession, if print data control for the next page is performed in advance, mask non-discharge complement processing is performed based on the latest non-discharge information. For example, if the defective nozzle data is updated by the non-discharge detection processing after printing of the previous page is completed, and the defective nozzle changes to a normal nozzle, nothing is done, and if a normal nozzle changes to a defective nozzle, the print data control that was started in advance is restarted. As a result, it becomes possible to correctly apply mask non-discharge complement processing. Therefore, for example, even if the defective nozzle data is updated by the non-discharge detection processing after printing of the previous page is completed, mask non-discharge complement processing is executed correctly.

[Configuration 1]
An image recording apparatus that performs recording on a recording medium by moving a recording head relative to the recording medium and discharging ink onto the recording medium from discharge ports of the recording head,
a transport mechanism that moves the recording head and the recording medium relatively in a transport direction;
a moving mechanism for moving the recording head in a direction intersecting the transport direction;
A control unit;
Equipped with
the recording head has a plurality of ejection openings arranged in the transport direction, the plurality of ejection openings being divided into a plurality of ejection opening groups in the transport direction;
when the transport mechanism relatively moves the recording head and the recording medium in the transport direction, the transport mechanism moves the recording head and the recording medium a distance corresponding to a length of one of the plurality of ejection opening groups, so that the ink is ejected from the ejection openings included in the one ejection opening group to a unit area having a predetermined length in the transport direction of the recording medium during the movement of the recording head in the intersecting direction by the movement mechanism,
the transport mechanism sequentially performs the relative movement, thereby sequentially ejecting the ink from each of the ejection opening groups included in the plurality of ejection opening groups onto one of the unit areas,
The control unit is
performing print data control to select the ejection port that ejects when the recording head is moving in the intersecting direction, based on image data and defective ejection port information that indicates the positions of ejection-defective ejection ports among the plurality of ejection ports;
When performing continuous printing on a plurality of pages of the recording medium, while a first image is being recorded on a first page based on first image data, advance print data control is performed on a second page next to the first page based on second image data;
An image recording device characterized in that, before recording a second image based on the advance print data control for the second image data, second defective outlet information is obtained, and if there is a difference when comparing the first defective outlet information used in the advance print data control with the second defective outlet information, it is determined whether to cancel the advance print data control.
[Configuration 2]
The image recording device according to claim 1, characterized in that the control unit compares the first defective outlet information with the second defective outlet information, and if any of the outlets has changed from a normal outlet to a defective outlet, cancels the result of the advance print data control and redoes the print data control using the second defective outlet information.
[Configuration 3]
The image recording device according to claim 1 or 2, characterized in that the control unit compares the first defective outlet information with the second defective outlet information, and if there is no outlet that has changed from a normal outlet to a defective outlet, records the second image using the results of the advance print data control.
[Configuration 4]
The image recording device described in claim 1 or 2, characterized in that the control unit compares the first defective outlet information with the second defective outlet information, and if any of the outlets has changed from a defective outlet to a normal outlet and if redoing the print data control would improve the image quality of the second image, cancels the result of the preceding print data control and redoes the print data control using the second defective outlet information.
[Configuration 5]
The image recording device according to any one of claims 1 to 3, characterized in that the control unit determines whether the printing mode in recording the second image is throughput priority, and if throughput priority is set, does not compare the first defective outlet information with the second defective outlet information.
[Configuration 6]
The image recording device according to any one of claims 1 to 4, characterized in that the control unit compares the first defective outlet information with the second defective outlet information when cleaning of the recording head is performed after the first image is recorded and before recording of the second image is started.
[Configuration 7]
A method for controlling an image recording device that performs recording on a recording medium by moving a recording head relatively to the recording medium and discharging ink onto the recording medium from an ejection port of the recording head, comprising the steps of:
The image recording device includes a transport mechanism that moves the recording head and the recording medium relatively in a transport direction, a movement mechanism that moves the recording head in a cross direction that intersects the transport direction, and a control unit;
the recording head has a plurality of ejection openings arranged in the transport direction, the plurality of ejection openings being divided into a plurality of ejection opening groups in the transport direction;
when the transport mechanism relatively moves the recording head and the recording medium in the transport direction, the transport mechanism moves the recording head and the recording medium a distance corresponding to a length of one of the plurality of ejection opening groups, so that the ink is ejected from the ejection openings included in the one ejection opening group to a unit area having a predetermined length in the transport direction of the recording medium during the movement of the recording head in the intersecting direction by the movement mechanism,
the transport mechanism sequentially performs the relative movement, thereby sequentially ejecting the ink from each of the ejection opening groups included in the plurality of ejection opening groups onto one of the unit areas,
The control unit:
a step of performing print data control to select an ejection port that ejects when the recording head is moving in the intersecting direction, based on image data and defective ejection port information that indicates the positions of ejection-defective ejection ports among the plurality of ejection ports;
When performing continuous printing on a plurality of pages of the recording medium, while a first image is being recorded on a first page based on first image data, performing advance print data control for second image data on a second page that is a next to the first page;
a step of acquiring second defective outlet information before recording a second image based on the preceding print data control for the second image data, and determining whether to cancel the preceding print data control if a difference is found when comparing the first defective outlet information used in the preceding print data control with the second defective outlet information;
11. A method for controlling an image recording apparatus comprising:
[Configuration 8]
An image recording device that is equipped with a recording head having a plurality of ejection ports and a control unit, and is capable of recording images continuously on a plurality of pages of a recording medium,
the control unit is capable of performing a preceding print data control for performing a print data control of a second page following the first page in advance during recording on the first page,
The control unit acquires defective outlet information indicating the position of a defective outlet among the plurality of outlets, compares the defective outlet information used in the advance print data control with the defective outlet information acquired after recording on the first page and before recording on the second page, and if there is a difference, cancels the result of the advance print data control and redoes print data control based on the latest defective outlet information.

5: Main rail, 6: Carriage, 7: Recording head, 8: Carriage motor, 11: Transport roller, 16: Pinch roller, 100: Image recording device, 300: Main control unit

Claims (8)

An image recording apparatus that performs recording on a recording medium by moving a recording head relative to the recording medium and discharging ink onto the recording medium from discharge ports of the recording head,
a transport mechanism that moves the recording head and the recording medium relatively in a transport direction;
a moving mechanism for moving the recording head in a direction intersecting the transport direction;
A control unit;
Equipped with
the recording head has a plurality of ejection openings arranged in the transport direction, the plurality of ejection openings being divided into a plurality of ejection opening groups in the transport direction;
when the transport mechanism relatively moves the recording head and the recording medium in the transport direction, the transport mechanism moves the recording head and the recording medium a distance corresponding to a length of one of the plurality of ejection opening groups, so that the ink is ejected from the ejection openings included in the one ejection opening group to a unit area having a predetermined length in the transport direction of the recording medium during the movement of the recording head in the intersecting direction by the movement mechanism,
the transport mechanism sequentially performs the relative movement, thereby sequentially ejecting the ink from each of the ejection opening groups included in the plurality of ejection opening groups onto one of the unit areas,
The control unit is
performing print data control to select the ejection port that ejects when the recording head is moving in the intersecting direction, based on image data and defective ejection port information that indicates the positions of ejection-defective ejection ports among the plurality of ejection ports;
When performing continuous printing on a plurality of pages of the recording medium, while a first image is being recorded on a first page based on first image data, a preceding print data control is performed on a second page next to the first page based on second image data;
An image recording device characterized in that, before recording a second image based on the advance print data control for the second image data, second defective outlet information is obtained, and if there is a difference when comparing the first defective outlet information used in the advance print data control with the second defective outlet information, it is determined whether to cancel the advance print data control. The image recording device according to claim 1, characterized in that the control unit compares the first defective outlet information with the second defective outlet information, and if any of the outlets has changed from a normal outlet to a defective outlet, cancels the result of the advance print data control and redoes the print data control using the second defective outlet information. The image recording device according to claim 1 or 2, characterized in that the control unit compares the first defective outlet information with the second defective outlet information, and if there is no outlet that has changed from a normal outlet to a defective outlet, records the second image using the results of the advance print data control. The image recording device described in claim 1 or 2, characterized in that the control unit compares the first defective outlet information with the second defective outlet information, and if any outlet has changed from a defective outlet to a normal outlet and if redoing the print data control would improve the image quality of the second image, cancels the result of the preceding print data control and redoes the print data control using the second defective outlet information. The control unit determines whether a print mode in which the second image is recorded is a throughput priority mode, and if the throughput priority mode is a throughput priority mode,
3. The image recording apparatus according to claim 1, wherein the defective ejection port information is not compared with the defective ejection port information. The image recording device according to claim 1 or 2, characterized in that the control unit compares the first defective outlet information with the second defective outlet information when cleaning of the recording head is performed after the first image is recorded and before recording of the second image is started. A method for controlling an image recording device that performs recording on a recording medium by moving a recording head relatively to the recording medium and discharging ink onto the recording medium from an ejection port of the recording head, comprising the steps of:
The image recording device includes a transport mechanism that moves the recording head and the recording medium relatively in a transport direction, a movement mechanism that moves the recording head in a cross direction that crosses the transport direction, and a control unit;
the recording head has a plurality of ejection openings arranged in the transport direction, the plurality of ejection openings being divided into a plurality of ejection opening groups in the transport direction;
when the transport mechanism relatively moves the recording head and the recording medium in the transport direction, the transport mechanism moves the recording head and the recording medium a distance corresponding to a length of one of the plurality of ejection opening groups, so that the ink is ejected from the ejection openings included in the one ejection opening group to a unit area having a predetermined length in the transport direction of the recording medium during the movement of the recording head in the intersecting direction by the movement mechanism,
the transport mechanism sequentially performs the relative movement, thereby sequentially ejecting the ink from each of the ejection opening groups included in the plurality of ejection opening groups onto one of the unit areas,
The control unit:
a step of performing print data control to select an ejection port that ejects when the recording head is moving in the intersecting direction, based on image data and defective ejection port information that indicates the positions of ejection-defective ejection ports among the plurality of ejection ports;
When performing continuous printing on a plurality of pages of the recording medium, while a first image is being recorded on a first page based on first image data, performing advance print data control for second image data on a second page that is a next to the first page;
a step of acquiring second defective outlet information before recording a second image based on the preceding print data control for the second image data, and determining whether to cancel the preceding print data control if a difference is found when comparing the first defective outlet information used in the preceding print data control with the second defective outlet information;
11. A method for controlling an image recording apparatus comprising: An image recording device that is equipped with a recording head having a plurality of ejection ports and a control unit, and is capable of recording images continuously on a plurality of pages of a recording medium,
the control unit is capable of performing a preceding print data control for performing a print data control of a second page following the first page in advance during recording on the first page,
The control unit acquires defective outlet information indicating the position of a defective outlet among the plurality of outlets, compares the defective outlet information used in the advance print data control with the defective outlet information acquired after recording on the first page and before recording on the second page, and if there is a difference, cancels the result of the advance print data control and redoes print data control based on the latest defective outlet information.

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