Image processing device, image processing method, and program

Abstract

To provide an image processing device which increases a printing speed of single-side printing while suppressing image quality deterioration, an image processing method and a program.SOLUTION: An image processing device for generating first image data D1 for a first printing part to be printed and second image data D2 for a second printing part to be printed on the same side as the first printing part comprises: an image data acquisition section for acquiring printing target image data D0 which are generated by half-toning; and a division section for dividing the printing target image data D0, which are acquired by the image data acquisition section, into the first image data D1 and the second image data D2. The division section divides the printing target image data D0 in such a manner that a region equal to or lower than a specific density in the printing target image data D0 is allocated to one of the first image data D1 and the second image data D2 and a region exceeding the specific density in the printing target image data D0 is allocated to both the first image data D1 and the second image data D2.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image processing device, an image processing method, and a program. [Background technology]

[0002] Conventionally, in a double-sided printing method for printing on both sides of recording paper, a printing method has been proposed in which a flushing mark for positioning is formed in the front printing process, and the back printing position is determined based on the position of the flushing mark in the back printing process (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-153234 A Summary of the Invention [Problem to be solved by the invention]

[0004] By connecting two printing devices and having the printing unit of one printing device print on the front side of a medium such as paper and the printing unit of the other printing device print on the back side of the medium, it is possible to achieve double-sided printing at the same printing speed (productivity) as single-sided printing. When single-sided printing is performed in a printing system equipped with multiple printing units in this way, only a single printing unit performs printing, so only a printing speed equivalent to that achieved when a single printing device performs single-sided printing can be achieved.

[0005] To increase the printing speed, if the printing unit is an inkjet print head, the drive frequency must be increased; however, applying a certain amount of color material to the printing surface of the medium takes time, which becomes a bottleneck and limits the improvement of the printing speed.

[0006] On the other hand, when two printing units share the work and perform single-sided printing on the same side of a medium, the amount of color material formed by each printing unit is smaller, and the printing speed can be increased accordingly. However, in this case, since one image is formed by two printing units, misalignment of the printing positions occurs in the multiple printing units, resulting in deterioration of image quality. This deterioration of image quality is particularly noticeable in areas with low density. Although it is possible to print with a certain degree of accuracy in the landing positions of ink droplets between two physically separated printing units by position correction using the above-mentioned flushing marks, it is difficult to prevent misalignment of the printing positions to the extent that image quality deterioration does not occur.

[0007] An object of the present invention is to provide an image processing apparatus, an image processing method, and a program that can increase the printing speed for single-sided printing while suppressing deterioration in image quality. [Means for solving the problem]

[0008] In one aspect, an image processing device is an image processing device that generates first image data for a first printing unit that prints on a medium and second image data for a second printing unit that prints on the medium on the same surface as the first printing unit, and is equipped with an image data acquisition unit that acquires image data to be printed generated by halftone processing, and a division unit that divides the image data to be printed acquired by the image data acquisition unit into the first image data and the second image data, and the division unit divides the image data to be printed so that areas of the image data to be printed that are below a specified density are assigned to one of the first image data and the second image data, and areas of the image data to be printed that exceed the specified density are assigned to both the first image data and the second image data. Effect of the Invention

[0009] According to this aspect, it is possible to increase the printing speed of single-sided printing while suppressing deterioration in image quality. [Brief description of the drawings]

[0010] [Figure 1]FIG. 1 is a diagram illustrating an internal configuration of a printing system according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a main control configuration of a printing system according to an embodiment. [Diagram 3] FIG. 1 is a diagram (part 1) for explaining division of image data according to an embodiment. [Figure 4] FIG. 2 is a second explanatory diagram for explaining division of image data according to an embodiment. [Diagram 5] FIG. 11 is an explanatory diagram for explaining print position correction according to an embodiment. [Figure 6] FIG. 11 is a third explanatory diagram for explaining division of image data according to an embodiment. [Figure 7] FIG. 11 is an explanatory diagram for explaining division of image data in the first reference technique. [Figure 8] FIG. 11 is an explanatory diagram for explaining division of image data in the second reference technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image processing device, an image processing method, and a program according to an embodiment of the present invention will be described below with reference to the drawings.

[0012] FIG. 1 is a diagram showing the internal configuration of a printing system 100 according to the present embodiment.

[0013] FIG. 2 is a diagram showing the main control configuration of the printing system 100.

[0014] The up-down direction, left-right direction, and front-rear direction shown in FIG. 1 are merely directions for convenience of explanation, but for example, the up-down direction is the vertical direction, and the left-right direction and front-rear direction are the horizontal directions.

[0015] As shown in Figures 1 and 2, the printing system 100 includes an image processing device 1 (see Figure 2), a medium supply device 110, a first printing device 120, an intermediate conveying device 130, a second printing device 140, and a medium discharge device 150.

[0016] The medium supply device 110, first printing device 120, intermediate conveyance device 130, second printing device 140, and medium discharge device 150 are arranged in series in this order on a conveyance path for medium M. In Fig. 1, the first supply path R1, second supply path R2, merging path R3, and first to fourth storage paths R5 to R8 for medium M are indicated by solid lines, and the reversal path R4 is indicated by a dashed line. Note that medium M is, for example, paper (sheets), but may be other media such as roll paper or film.

[0017] The medium supply device 110 includes a first supply unit 111, a second supply unit 112 disposed below the first supply unit 111, and a plurality of conveying roller pairs 113 that nip and convey the medium M. The first supply unit 111 and the second supply unit 112 include stacking tables 111a and 112a that can be raised and lowered and on which the medium M is stacked, and suction conveying units 111b and 112b that suction and unload the uppermost medium M stacked on the stacking tables 111a and 112a and convey the medium M. A first supply path R1 for the medium M supplied from the first supply unit 111 and a second supply path R2 for the medium M supplied from the second supply unit 112 join at a joining path R3. The medium supply device 110 may include only a single supply unit.

[0018] The first printing device 120 has a plurality of transport roller pairs 121 that nip and transport the medium M, a first printing unit 122 that prints on the medium M, an adsorption transport unit 123 that is disposed opposite the first printing unit 122 and transports the medium M while adsorbing it, and an operation panel 124. The first printing unit 122 has a plurality of first print heads 122a that are arranged for each color of ink, for example, black, cyan, magenta, and yellow. Each of the plurality of first print heads 122a is, for example, a line-type inkjet head that extends in the main scanning direction, and a plurality of nozzles that eject ink are arranged in the main scanning direction. The operation panel 124 has a display that displays various information, and an operation key or touch panel that accepts information input by a user.

[0019] The intermediate conveying device 130 has a plurality of conveying roller pairs 131 that convey the medium M while nipping it, a switchback roller pair 132 that inverts the medium M on the inversion path R4, an inversion storage section 133 that stores the medium M whose front and back are inverted by the switchback roller pair 132, and a conveying path switching section 134. The conveying path switching section 134 is, for example, a flipper, and switches the conveying path between a path that inverts the medium M from the junction path R3 through the inversion path R4 and returns it to the junction path R3, and a path that remains on the junction path R3 and does not invert the medium M.

[0020] The second printing device 140 has a plurality of conveying roller pairs 141 that nip and convey the medium M, a second printing unit 142 that prints on the medium M, an adsorption conveying unit 143 that is disposed opposite the second printing unit 142 and adsorbs and conveys the medium M, an operation panel 144, and an image reading unit 145. The second printing unit 142 has a plurality of second print heads 142a that are arranged for each color ink of black, cyan, magenta, and yellow, for example. Each of the plurality of second print heads 142a is, for example, a line-type inkjet head that extends in the main scanning direction, and a plurality of nozzles that eject ink are arranged in the main scanning direction. The operation panel 144 has a display that displays various information, and an operation key or touch panel that accepts information input by a user. The image reading unit 145 has an image reading sensor such as a CIS (Contact Image Sensor) and reads a reference mark Dc (see FIG. 3B), for example a cross, printed by the first printing unit 122 in a color (yellow) that is difficult to see at a position (corner such as the upper left) that does not interfere with the formed image. Then, the second printing unit 142 changes the allocation of the ejection drop data corresponding to the image data to each nozzle of the second printing head 142a based on the detected position of the reference mark Dc read by the image reading unit 145. In the example of FIG. 5, in the second printing head 142a, three nozzles corresponding to the ejection area represented by the hatched portion of the ejection drop data are shifted in the main scanning direction to three nozzles indicated by solid arrows, three nozzles indicated by dashed arrows, etc., depending on the detected position of the reference mark Dc.

[0021] In addition, in the intermediate conveying device 130, when the conveying path switching unit 134 switches the conveying path to a path that does not turn the medium M over while keeping it as the junction path R3, the first printing unit 122 of the first printing device 120 and the second printing unit 142 of the second printing device 140 can print on the same side of the medium M. In other words, the first printing unit 122 and the second printing unit 142 can share the task of printing one side of a single image.

[0022] The medium ejection device 150 has an introduction section 151, a first normal storage section 152, an upper transport section 153, an intermediate transport section 154, a second normal storage section 155, an abnormal storage section 156, and a plurality of transport roller pairs 157.

[0023] A plurality of pairs of conveying rollers 157 convey the medium M while nipping it in each section such as the introduction section 151. A path switching section 151a, for example a flipper, is disposed inside the introduction section 151. This path switching section 151a switches the junction path R3 continuing from the second printing device 140 to the introduction section 151 between a first storage path R5 leading to the first normal storage section 152 and a second storage path R6 leading to the second normal storage section 155 and the abnormal storage section 156. Although not shown, the introduction section 151 may have a reversing path that reverses the front and back of the medium M to be discharged.

[0024] The first normal storage section 152 and the second normal storage section 155 have liftable stacking platforms 152a, 155a on which media M are stacked. A second storage path R6 leading to the second normal storage section 155 and the abnormal storage section 156 is disposed in the upper transport section 153 located above the first normal storage section 152. The path switching section 153a of the upper transport section 153 is, for example, a flipper, and switches the second storage path R6 to a third storage path R7 leading to the second normal storage section 155 and a fourth storage path R8 leading to the abnormal storage section 156. The intermediate transport section 154 located between the first normal storage section 152 and the second normal storage section 155 has the third storage path R7 leading to the second normal storage section 155 and the fourth storage path R8 leading to the abnormal storage section 156 located above the second normal storage section 155.

[0025] The image processing device 1 shown in FIG.

[0026] The control unit 10 has one or more processors (e.g., CPU: Central Processing Unit) that function as an arithmetic processing device that controls the operation of each part of the image processing device 1. For example, this processor reads and executes a predetermined program from the storage unit 20 or from a storage medium (non-transient computer-readable recording medium) that is detachable from the image processing device 1, thereby functioning as an image data acquisition unit 11 and a division unit 12, which will be described later. In this manner, the control unit 10 (or the image processing device 1 that includes the control unit 10 and the storage unit 20) functions as an example of a computer that executes a program. The control unit 10 may control the operation of each part of the printing system 100 (the medium supply device 110, the first printing device 120, the intermediate conveying device 130, the second printing device 140, and the medium discharge device 150). In this case, the image processing device 1 functions as a controller of the printing system 100.

[0027] The storage unit 20 has memories such as a ROM (Read Only Memory), which is a read-only semiconductor memory in which a specific control program is pre-recorded, and a RAM (Random Access Memory), which is a semiconductor memory that can be written to and read at any time and is used as a working memory area as needed when the processor executes various control programs.

[0028] The interface unit 30 transmits and receives various information between devices such as the first printing device 120 and the second printing device 140. For example, the interface unit 30 transmits first image data D1 (see FIG. 3(b)) to the first printing unit 122, and transmits second image data D2 (see FIG. 3(c)) to the second printing unit 142.

[0029] The image data acquisition unit 11 of the control unit 10 acquires the print target image data D0 (see FIG. 3(a)) generated by halftone processing. The image data acquisition unit 11 may acquire the print target image data D0 generated by halftone processing of an image processing unit (not shown) included in the image processing device 1 or an image processing unit other than the image processing device 1, for example, by receiving the print target image data D0, or may acquire the print target image data D0 by performing halftone processing on image data received from a user terminal. The print target image data D0 generated by this halftone processing is, for example, color-converted from RGB format image data generated by the user terminal to CMYK format image data, and halftone-processed by known image processing such as error diffusion or dithering, and multi-valued to ejection drop data with a maximum number of six drops per pixel.

[0030] 3(a) to 3(c), the division unit 12 divides the print target image data D0 acquired by the image data acquisition unit 11 into first image data D1 for the first printing unit 122 and second image data D2 for the second printing unit 142. Note that while Fig. 3 shows print target image data D0 that can be printed using only black ink, the print target image data D0 may be image data of a color image that is printed in color using a plurality of inks.

[0031] In this embodiment, printing is not performed on the medium M by a single first print head 122a ejecting ink as in the comparative example shown in FIG. 6(a), but rather, as shown in FIG. 6(b), the first print head 122a and the second print head 142a eject ink in the number of drops assigned to them, overlapping them onto one pixel, to perform single-sided printing. In this way, the amount of color material to be placed on the printing surface of the medium M can be shared between the first print head 122a and the second print head 142a, so that the number of drops ejected by each of the first print head 122a and the second print head 142a is reduced, and the printing speed can be increased accordingly. In general, the upper limit printing speed from the viewpoint of the print heads (the first print head 122a and the second print head 142a) is determined by the drive frequency, but the drive frequency decreases as the number of drops of the multi-drop increases.

[0032] Incidentally, as in reference technology 1 shown in Figure 7, if a single image data to be printed is divided evenly into, for example, identical ejected drop data in the upper left of Figure 7 and ejected drop data in the upper right of Figure 7, and printed by an upstream printing unit and a downstream printing unit, the actual print result will have a printing position misalignment between the two printing units, as shown at the bottom of Figure 7.

[0033] Also, as in the reference technique 2 shown in FIG. 8, when a single print target image data is divided into the discharge drop data in the upper left of FIG. 8 and the discharge drop data in the upper right of FIG. 8 so that the dots do not overlap, and the data is printed by the upstream printing unit and the downstream printing unit separately, good image quality can be obtained if the landing positions are printed without any misalignment, as in the print result in the lower left of FIG. 8. However, with the known alignment technique using the above-mentioned reference mark Dc in the upstream machine (first printing unit 122) and downstream machine (second printing unit 142), the printing position misalignment becomes large, as in the print result in the lower right of FIG. 8, and it is not possible to completely eliminate the printing position misalignment. Therefore, in the case of a density range expressed by the sparseness and density of dots ON / OFF, such as in a highlight part, the occurrence of the landing position misalignment significantly deteriorates the graininess. This kind of image quality degradation is noticeable in low density areas, both in the case of the reference technique 1 shown in FIG. 7 and the reference technique 2 shown in FIG. 8. As shown in FIG. 8, the drop data may be divided so that the dots do not overlap, but this increases the processing load, giving rise to problems that affect the overall processing speed.

[0034] Therefore, the division unit 12 divides the image data D0 to be printed so that, for example, for each color of ink ejected by the first print head 122a and the second print head 142a, areas (dots) of the image data D0 to be printed that are below a specified density are assigned to one of the first image data D1 and the second image data D2, and areas that exceed the specified density are assigned to both the first image data D1 and the second image data D2.

[0035] As an example, the division unit 12 assigns the specified density of the region exceeding the specified density to one of the first image data D1 and the second image data D2, and assigns the remaining density to the other. In the example shown in Fig. 4, the specified density is a density corresponding to the drop number 3, which is half of the maximum drop number 6 of the first print head 122a and the second print head 142a, and in the print target image data D0 in which each region is represented by the drop numbers 0 to 6, the region with the drop numbers 1 to 3 that is equal to or less than the specified density is assigned to the first image data D1, the region with the drop numbers 4 to 6 that exceeds the specified density is truncated at the specified density to the first image data D1 and assigned the drop number 3, and the remaining drop numbers 1 to 3, which are the difference between the print target image data D0 and the first image data D1, are assigned to the second image data D2. That is, if the drop value at the coordinates (x, y) of the image data D0 to be printed is f(x, y)_A and the maximum drop number of the image data D0 to be printed is maxdrop, the drop value of the first image data D1 is applied to the image data D0 to be printed, and if f(x, y)_B≧(maxdrop / 2), it is maxdrop / 2, and if f(x, y)_B<(maxdrop / 2), it is f(x, y)_A. The drop value of the second image data D2 is f(x, y)_C=f(x, y)_A-f(x, y)_B. Each area represented by one square in FIG. 4 corresponds to each nozzle of the first print head 122a and the second print head 142a, but may correspond to multiple nozzles, for example. In this case, multiple nozzles are responsible for discharging ink in each area.

[0036] In the image data D0 to be printed shown in Figure 3(a), the character portion Da "ABCDE12345" has the maximum density (for example, 6 drops), so for example, a drop number of 3 is assigned to each of the first image data D1 shown in Figure 3(b) and the second image data D2 shown in Figure 3(c).

[0037] Next, the density of the light and dark portion Db of the image data to be printed D0 becomes continuously lighter from the left end (e.g., drop number 6) to the right end (e.g., drop number 0), and the area from the center to the right is below a specified density (e.g., drop number 3). In this case, in the first image data D1, the drop number 3 for the specified density is assigned from the left end to the center, and the drop numbers 3 to 0 are assigned from the center to the right end. Also, in the second image data D2, the drop numbers 3 to 0 are assigned from the left end to the center, and the drop number 0 (no printing) is assigned to the area below the specified density in the image data to be printed D0 from the center to the right end.

[0038] In this embodiment, the print target image data D0 is printed in the order of, for example, black, cyan, magenta, and yellow by the first print head 122a, and black, cyan, magenta, and yellow by the second print head 142a, and the color may vary when black is printed by both the first print head 122a and the second print head 142a compared to when black is printed by only the first print head 122a. In that case, a known color adjustment may be performed, for example, by adjusting the amount of droplets of each color ejected by the first print head 122a and the second print head 142a.

[0039] The division unit 12 may obtain the ink consumption (remaining amount) of the first printing unit 122 and the second printing unit 142 from the first printing device 120 and the second printing device 140, or may obtain the ink consumption (remaining amount) from the first image data D1 and the second image data D2 generated in the past. Then, when the ink consumption of one of the first printing unit 122 and the second printing unit 142 exceeds a specified value (the remaining amount falls below a specified value) or is biased, the division unit 12 may switch the allocation method of the print target image data D0 to the first image data D1 and the second image data D2. In other words, the division unit 12 may switch the allocation method between the first image data D1 and the second image data D2 so that the first image data D1 becomes the second image data D2 for the second printing unit 142 rather than for the first printing unit 122, and the second image data D2 becomes the first image data D1 for the first printing unit 122 rather than for the second printing unit 142.

[0040] Alternatively, the division unit 12 may switch the allocation of the print target image data D0 to the first image data D1 and the second image data D2 at any timing, such as every specified number of prints or every specified time. Furthermore, the division unit 12 may change the specified density that serves as the basis for allocation (for example, the number of drops is 3, which is half the maximum number of drops of 6) at any timing (for example, change the number of drops to 2 or 4).

[0041] In the present embodiment, the division unit 12 assigns the area of ​​the image data D0 to be printed that is equal to or less than the specified density to the first image data D1, assigns the area of ​​the image data D0 to be printed that is greater than the specified density to the first image data D1, and assigns the remaining density to the second image data D2. Alternatively, the division unit 12 may assign the area of ​​the image data D0 to be printed that is equal to or less than the specified density to the second image data D2, or assigns the area of ​​the image data D0 to be printed that is greater than the specified density to the second image data D2, and assigns the remaining density to the first image data D1. The division unit 12 may not use the specified density as a reference for the allocation of the area of ​​the image data D0 to be printed that is greater than the specified density, but may arbitrarily allocate the area, for example, half to the first image data D1 and half to the second image data D2. The division unit 12 may also change the method of allocation to the first image data D1 and the second image data D2 for each position (area) of the image data D0 to be printed.

[0042] In addition, in this embodiment, a total of two printing units, the first printing unit 122 and the second printing unit 142, are arranged, but when three or more printing units are arranged, the division unit 12 may divide the image data to be printed D0 into image data for three or more printing units. In this case, the division unit 12 may divide the image data to be printed D0 so that an area of ​​the image data to be printed D0 that is equal to or less than a specified density is assigned to image data for one of the printing units (for example, one of the first image data D1 and the second image data D2), and an area of ​​the image data to be printed D0 that exceeds the specified density is assigned to image data for three or more printing units (for example, three or more image data including the first image data D1 and the second image data D2).

[0043] Furthermore, in this embodiment, the first print head 122a of the first printing unit 122 and the second print head 142a of the second printing unit 142 are capable of adjusting the amount of ink ejected by the number of drops ejected, but the amount of liquid droplets per drop may also be adjustable.

[0044] Furthermore, the above-described printing system 100 is merely an example, and the image processing device 1 may be disposed in a location different from the first printing device 120 and the second printing device 140. Furthermore, the first printing unit 122 and the second printing unit 142 may be disposed in a single printing device. In this case, the printing device includes the image data acquisition unit 11 and the division unit 12, and thus also functions as an image processing device.

[0045] In the present embodiment, the first print head 122a of the first print unit 122 and the second print head 142a of the second print unit 142 are preferably line-type inkjet heads, but the printing method of the first print unit 122 and the second print unit 142 may be other printing methods such as a laser print method. The first print unit that prints the first image data D1 and the second print unit that prints the second image data D2 are not limited to those that are separately arranged like the first print unit 122 and the second print unit 142 of the present embodiment, and for example, among a single printing unit in which a plurality of print heads capable of ejecting black ink (an example of the same color) are integrally arranged at the same position in the main scanning direction, the upstream black print head may function as the first print unit and the downstream black print head may function as the second print unit.

[0046] In the present embodiment described above, the image processing device 1 generates first image data D1 for the first printing unit 122 that prints on the medium M, and second image data D2 for the second printing unit 142 that prints on the medium M on the same surface as the first printing unit 122. The image processing device 1 includes an image data acquisition unit 11 that acquires print target image data D0 generated by halftone processing, and a division unit 12 that divides the print target image data D0 acquired by the image data acquisition unit 11 into first image data D1 and second image data D2. The division unit 12 divides the print target image data D0 so that an area of ​​the print target image data D0 that is equal to or less than a specified density (for example, the number of drops is 3) is assigned to the first image data D1 (one example of the first image data D1 and the second image data D2), and an area of ​​the print target image data D0 that exceeds the specified density is assigned to both the first image data D1 and the second image data D2.

[0047] From a method perspective, the image processing method is an image processing method in which first image data D1 for a first printing unit 122 that prints on a medium M and second image data D2 for a second printing unit 142 that prints on the medium M on the same surface as the first printing unit 122 are generated by a computer (e.g., the control unit 10 or the image processing device 1), and includes acquiring image data D0 to be printed generated by halftone processing, and dividing the acquired image data D0 to be printed into first image data D1 and second image data D2, wherein areas of the image data D0 to be printed that are below a specified density are assigned to the first image data D1 (an example of one of the first image data D1 and the second image data D2), and dividing the image data D0 to be printed so that areas of the image data D0 to be printed that are below a specified density are assigned to both the first image data D1 and the second image data D2.

[0048] From the perspective of the program, the program is a program for generating first image data D1 for the first printing unit 122 that prints on the medium M and second image data D2 for the second printing unit 142 that prints on the medium M on the same surface as the first printing unit 122, and causes a computer (e.g., the control unit 10 or the image processing device 1) to realize the following functions: acquire image data D0 to be printed generated by halftone processing; and divide the acquired image data D0 to be printed into first image data D1 and second image data D2, and divide the image data D0 to be printed so that areas of the image data D0 to be printed that are below a specified density are assigned to the first image data D1 (one example of the first image data D1 and the second image data D2), and areas of the image data D0 to be printed that exceed the specified density are assigned to both the first image data D1 and the second image data D2.

[0049] According to these image processing device 1, image processing method, and program, in a relatively low density area of ​​the image data to be printed D0 where image quality deterioration due to misalignment of the print positions between the first printing unit 122 and the second printing unit 142 is likely to occur, image quality deterioration can be suppressed by having one of the first printing unit 122 and the second printing unit 142 print. Also, in a relatively high density area of ​​the image data to be printed D0 where image quality deterioration due to misalignment of the print positions is unlikely to occur, the printing speed can be increased by having both the first printing unit 122 and the second printing unit 142 share the printing. Thus, according to this embodiment, it is possible to increase the printing speed of single-sided printing while suppressing image quality deterioration.

[0050] Furthermore, in this embodiment, the division unit 12 divides the image data D0 to be printed so that the area of ​​the image data D0 to be printed that exceeds a specified density (for example, the number of drops is 3) is assigned to the first image data D1 (one example of the first image data D1 and the second image data D2), and the remaining density (for example, the number of drops is 1 to 3) is assigned to the second image data D2 (the other example of the first image data D1 and the second image data D2).

[0051] This allows the specified density that serves as the basis for allocating an area of ​​the image data D0 to only one of the first image data D1 and the second image data D2 to be set as the maximum density that can be allocated to the first image data D1 (or the second image data D2), making it possible to more reliably increase the printing speed for single-sided printing with a simple calculation.

[0052] Furthermore, in this embodiment, the division unit 12 switches the allocation of the print target image data D0 between the first image data D1 and the second image data D2 based on the ink consumption amounts of the first printing unit 122 and the second printing unit 142.

[0053] This makes it possible to prevent imbalance in the amount of ink consumed by the first printing unit 122 and the second printing unit 142.

[0054] The present invention is not limited to the above-described embodiment as it is, and the components can be modified and embodied without departing from the gist of the invention in the implementation stage. In addition, various inventions can be formed by appropriate combinations of the multiple components disclosed in the above-described embodiment. For example, all the components shown in the embodiment may be appropriately combined. Of course, various modifications and applications are possible without departing from the spirit of the invention. The invention described in the claims at the time of filing of this application is appended below.

[0055] [Appendix 1] An image processing device that generates first image data for a first printing unit that prints on a medium and second image data for a second printing unit that prints on the medium on the same surface as the first printing unit, an image data acquisition unit that acquires print target image data generated by halftone processing; a division unit that divides the print target image data acquired by the image data acquisition unit into the first image data and the second image data, The dividing unit divides the image data to be printed so as to allocate an area of ​​the image data to be printed that is equal to or less than a specified density to one of the first image data and the second image data, and to allocate an area of ​​the image data to be printed that is greater than the specified density to both the first image data and the second image data. 13. An image processing device comprising:

[0056] [Appendix 2] The dividing unit divides the image data to be printed so as to allocate a specified density portion of an area of ​​the image data to be printed that exceeds the specified density to one of the first image data and the second image data, and to allocate the remaining density portion to the other of the first image data and the second image data. 2. The image processing device according to claim 1 .

[0057] [Appendix 3] The division unit switches the allocation of the print target image data to the first image data and the allocation of the print target image data to the second image data based on the ink consumption amounts of the first printing unit and the second printing unit. 3. The image processing device according to claim 1 or 2.

[0058] [Appendix 4] An image processing method for generating, by a computer, first image data for a first printing section that prints on a medium, and second image data for a second printing section that prints on the medium on the same surface as the first printing section, comprising: Obtaining image data to be printed that has been generated by halftone processing; Dividing the acquired image data to be printed into the first image data and the second image data, wherein an area of ​​the image data to be printed that is equal to or less than a specified density is assigned to one of the first image data and the second image data, and an area of ​​the image data to be printed that is greater than the specified density is assigned to both the first image data and the second image data. 13. An image processing method comprising:

[0059] [Appendix 5] A program for generating first image data for a first printing section that prints on a medium and second image data for a second printing section that prints on the medium on the same surface as the first printing section, A function for acquiring image data to be printed that has been generated by halftone processing; a function of dividing the acquired image data to be printed into the first image data and the second image data, wherein an area of ​​the image data to be printed that is equal to or less than a specified density is assigned to one of the first image data and the second image data, and an area of ​​the image data to be printed that is greater than the specified density is assigned to both the first image data and the second image data; A program characterized by causing a computer to realize the above. [Explanation of symbols]

[0060] 1 Image processing device 10 Control section 11 Image data acquisition section 12 Division 20 Memory section 30 Interface section 100 Printing System 110 Media supply device 120 1st printing device 122 1st Printing Department 122a First print head 130 Intermediate conveying device 140 2nd printing device 142 2nd Printing Department 142a Second print head 145 Image reading unit 150 Media ejector D0 Image data to be printed D1 First image data D2 Second image data Da character part Db shading area DC reference mark M medium R1 First supply route R2 Second supply route R3 Merging route R4 Reversal Path R5 1st storage route R6 Second storage route R7 3rd storage route R8 4th storage route

Claims

1. An image processing device that generates first image data for a first printing unit that prints on a medium and second image data for a second printing unit that prints on the medium on the same surface as the first printing unit, an image data acquisition unit that acquires print target image data generated by halftone processing; a division unit that divides the print target image data acquired by the image data acquisition unit into the first image data and the second image data, The dividing unit divides the image data to be printed so as to allocate an area of ​​the image data to be printed that is equal to or less than a specified density to one of the first image data and the second image data, and to allocate an area of ​​the image data to be printed that is greater than the specified density to both the first image data and the second image data.

13. An image processing device comprising:

2. The dividing unit divides the image data to be printed so as to allocate a specified density portion of an area of ​​the image data to be printed that exceeds the specified density to one of the first image data and the second image data, and to allocate the remaining density portion to the other of the first image data and the second image data.

2. The image processing apparatus according to claim 1,

3. The division unit switches the allocation of the print target image data to the first image data and the second image data based on the ink consumption amounts of the first printing unit and the second printing unit.

3. The image processing apparatus according to claim 1, wherein the image processing apparatus is a computer.

4. An image processing method for generating, by a computer, first image data for a first printing section that prints on a medium, and second image data for a second printing section that prints on the medium on the same surface as the first printing section, comprising: Obtaining image data to be printed that has been generated by halftone processing; Dividing the acquired image data to be printed into the first image data and the second image data, wherein an area of ​​the image data to be printed that is equal to or less than a specified density is assigned to one of the first image data and the second image data, and an area of ​​the image data to be printed that is greater than the specified density is assigned to both the first image data and the second image data.

13. An image processing method comprising:

5. A program for generating first image data for a first printing unit that prints on a medium and second image data for a second printing unit that prints on the medium on the same surface as the first printing unit, A function for acquiring image data to be printed that has been generated by halftone processing; a function of dividing the acquired image data to be printed into the first image data and the second image data, wherein an area of ​​the image data to be printed that is equal to or less than a specified density is assigned to one of the first image data and the second image data, and an area of ​​the image data to be printed that is greater than the specified density is assigned to both the first image data and the second image data; A program characterized by causing a computer to realize the above.

Images