JP2021138051A - Printer and color measurement method - Google Patents

Abstract

To achieve improvement for measuring a color of a patch by a color measurement unit mounted on a carriage.SOLUTION: A color measurement method by a printer that prints an image on a printing medium with the combination of main scanning of discharging ink to the printing medium by a printing head mounted on a carriage following the movement of the carriage along the first direction and a relative movement between the carriage and the printing medium in the second direction intersecting the first direction, comprises: a printing data generation step of generating printing data expressing an image; a printing step of making the printing head discharge ink based on the printing data; and a color measurement step of making the color measurement unit mounted on the carriage measure a color of a first patch for color measurement. The printing data generation step generates printing data in which the first patch is synthesized at a position which is a blank area not overlapping with the image and through which the color measurement unit passes at the execution of the final main scanning for printing the image, and performs the color measurement step of measuring a color of the first patch printed on the printing medium on the basis of the printing data by the printing step in the final main scanning.SELECTED DRAWING: Figure 3

Description

The present invention relates to a printing apparatus and a color measuring method.

The printer generates image data in which a color patch is combined with the margin of the user image input from the client PC, prints based on this image data on paper, and the user outputs the user image and color ejected from the printer. The paper on which the patch is printed is set in the image reading unit, and the color patch is measured (see Patent Document 1). Further, according to the above-mentioned Document 1, a color measuring device may be provided in the paper carrying path of the printer to obtain the color measurement value of the color patch.

In addition, a recording head that ejects cyan (C), magenta (M), yellow (Y), and black (K) inks is mounted on a carriage that moves in the main scanning direction, and a patch printed on a print medium is measured. A configuration in which a carriage supports a color measuring camera for performing color is also disclosed (see Patent Document 2).

Japanese Unexamined Patent Publication No. 2006-94295 Japanese Unexamined Patent Publication No. 2015-131483

As in Document 1, the paper ejected from the printer is set in the image reading unit to measure the color of the patch, or the patch of the printed paper is measured by the colorimeter provided in the paper carrying path. In the configuration, it takes a long time from printing the patch to measuring the color. By measuring the color of the patch, the color of the print result can be evaluated, and if the color measurement value is not an appropriate value, printing can be stopped or the like. Therefore, the longer the time from patch printing to color measurement, the more improper printing may continue during that time, resulting in increased waste of ink and paper and waste of time.

By mounting the color measuring camera on the carriage as described in Document 2, the time from printing the patch to measuring the color can be shortened.
However, the number of main scans of the head and the amount of relative movement between the carriage and the print medium between the main scans and the print medium vary depending on the printing conditions used in the printing process. The relative positional relationship between the color measuring camera mounted on the carriage and the print medium is not constant. Therefore, in order for the patch to be able to measure the color with the color measuring camera under any printing conditions, it is necessary to print each patch in a large size, which increases the consumption of paper and ink. ..

The printing apparatus includes a printing head that ejects ink to a printing medium, a color measuring unit that measures colors, and a carriage that mounts the printing head and the color measuring unit and moves along a first direction. The main scan in which the print head ejects ink with the movement of the carriage along the first direction, and the relative movement of the carriage and the print medium in the second direction intersecting the first direction. The image is printed on the print medium by the combination. Then, the printing apparatus has a print data generation unit that generates print data expressing the image, and a print color measurement control unit that controls ink ejection by the print head based on the print data and color measurement by the color measurement unit. The print data generation unit is used for color measurement at a position of a blank area that does not overlap with the image and at a position where the color measurement unit passes when the final main scan for printing the image is executed. The print data obtained by synthesizing the first patch of the above is generated, and the print color measurement control unit prints the first patch printed on the print medium based on the print data on the color measurement unit in the final main scan. Let the color be measured.

The main scan in which the print head mounted on the carriage ejects ink to the print medium as the carriage moves along the first direction, and the relative relationship between the carriage and the print medium in the second direction intersecting the first direction. The color measurement method by the printing apparatus that prints an image on the print medium by combining the movement is a print data generation step of generating print data expressing the image, and the print head ejects ink based on the print data. A printing step of performing the above and a color measuring step of measuring the color of the first patch for color measurement by the color measuring unit mounted on the carriage are provided. In the print data generation step, the first patch is synthesized at a position of a blank area that does not overlap with the image and at a position where the color measuring unit passes when the final main scan for printing the image is executed. The color measurement step of generating print data and measuring the color of the first patch printed on the print medium based on the print data by the print step is performed in the final main scan.

A block diagram showing a simple device configuration. The figure which shows the specific example of the structure including a transport part and a carriage. A flowchart showing a print color measurement process. The figure explaining the process of steps S100-S140 by using a specific example. The figure explaining the process of step S160 with a specific example. Flow chart of print color measurement processing including error processing according to evaluation of color measurement value. FIG. 7A is a diagram showing an example of image data in which a plurality of first patches of different colors are combined, and FIG. 7B is a diagram showing an example of image data in which specific marks are combined. A flowchart of a print color measurement process including printing of an OC layer. The figure explaining the process of steps S131 and S141 by using a specific example. The figure explaining the process of step S161 with a specific example.

Hereinafter, embodiments of the present invention will be described with reference to each figure. It should be noted that each figure is merely an example for explaining the present embodiment. Since each figure is an example, the ratio and shape may not be accurate, they may not be consistent with each other, or some parts may be omitted.

1. 1. Device configuration:
FIG. 1 simply shows the configuration of the printing apparatus 10 according to the present embodiment.
The printing device 10 includes a control unit 11, a display unit 13, an operation receiving unit 14, a communication IF 15, a transport unit 16, a carriage 17, a printing head 18, a color measuring unit 19, and the like. IF is an abbreviation for interface. The control unit 11 includes one or more ICs having a CPU 11a, a ROM 11b, a RAM 11c, etc. as a processor, another non-volatile memory, and the like.

In the control unit 11, the processor, that is, the CPU 11a, generates print data by executing arithmetic processing according to one or more programs 12 stored in the ROM 11b or other memory using the RAM 11c or the like as a work area. Functions such as unit 12a and print color measurement control unit 12b are realized. The program 12 is also called a print color measurement control program or the like. The processor is not limited to one CPU, and may be configured to perform processing by a plurality of CPUs or a hardware circuit such as an ASIC, or the CPU and the hardware circuit cooperate to perform processing. It may be a configuration to be performed.

The display unit 13 is a means for displaying visual information, and is composed of, for example, a liquid crystal display, an organic EL display, or the like. The display unit 13 may be configured to include a display and a drive circuit for driving the display. The operation receiving unit 14 is a means for receiving an operation by a user, and is realized by, for example, a physical button, a touch panel, a mouse, a keyboard, or the like. Of course, the touch panel may be realized as one function of the display unit 13.

The display unit 13 and the operation reception unit 14 may be a part of the configuration of the printing device 10, but may be peripheral devices externally attached to the printing device 10. The communication IF 15 is a general term for one or more IFs for the printing device 10 to connect to the outside by wire or wirelessly in accordance with a predetermined communication protocol including a known communication standard.

The transport unit 16 is a means for transporting the print medium, and includes a roller, a motor for rotating the roller, and the like. The print head 18 ejects ink to a print medium by an inkjet method to execute printing. The color measuring unit 19 is a means for measuring the color of an object. The format of the color measurement value generated and output by the color measurement unit 19 as the color measurement result is, for example, L ^* a ^* b ^{* L *} a ^* b ^* data according to the color space specified by the CIE (International Commission on Illumination). Or, it may be RGB data which is a combination of gradation values for each of red (R), green (G), and blue (B).

The carriage 17 is a mechanism capable of reciprocating along the first direction by receiving power from a motor (not shown). The first direction is also called the main scanning direction. In the present embodiment, the carriage 17 is equipped with a print head 18 and a color measuring unit 19.

The configuration of the printing device 10 shown in FIG. 1 may be realized by one printer, or may be realized by a plurality of devices connected so as to be able to communicate with each other.
That is, the printing device 10 may actually be the printing system 10. The printing system 10 includes, for example, an information processing device that functions as a control unit 11, and a printer that includes a transport unit 16, a carriage 17, a print head 18, and a color measuring unit 19. With such a printing device 10 or a printing system 10, the color measuring method of the present embodiment is realized.

FIG. 2 shows a specific example of the structure including the transport unit 16 and the carriage 17. In the upper part of FIG. 2, the specific example is shown from a viewpoint orthogonal to the transport direction Df of the print medium 30. Further, in the lower part of FIG. 2, a part of the specific example is shown from a viewpoint from above.

According to FIG. 2, the transport unit 16 includes a feeding shaft 20 upstream of the transport and a take-up shaft 23 downstream of the transport. The upstream and downstream of transportation are simply referred to as upstream and downstream. A long printing medium 30 wound in a roll shape around the feeding shaft 20 and the winding shaft 23 is stretched along the transport direction Df. The print medium 30 is conveyed in the transfer direction Df. The print medium 30 may be paper or a medium made of a material other than paper. Further, the print medium 30 may be a medium having a double structure composed of a sheet called a label, a sticker, or the like and a mount on which the sheet is attached with an adhesive.

In the upper example in FIG. 2, the printing medium 30 wound around the feeding shaft 20 is fed downstream by rotating the feeding shaft 20 clockwise. A front drive roller 21 is provided at a downstream position of the feeding shaft 20, and a rear drive roller 22 is provided at an upstream position of the take-up shaft 23. The front drive roller 21 rotates clockwise to convey the print medium 30 fed from the feeding unit 20 downstream. A nip roller 21n is provided for the front drive roller 21. The nip roller 21n abuts on the print medium 30 to sandwich the print medium 30 with the front drive roller 21.

By rotating the rear drive roller 22 clockwise, the print medium 30 conveyed downstream by the front drive roller 21 is conveyed further downstream. A nip roller 22n is provided for the rear drive roller 22. The nip roller 22n abuts on the print medium 30 to sandwich the print medium 30 with the rear drive roller 22.

A print head 18 that ejects ink from above with respect to the print medium 30 is arranged between the front drive roller 21 and the rear drive roller 22. As can be seen from FIG. 2, the print head 18 and the color measuring unit 19 are mounted on the carriage 17.

The print head 18 can eject inks of a plurality of colors such as CMYK. Although not shown, the print head 18 has a nozzle row for each ink of CMYK. The nozzle row corresponding to one color ink is composed of a plurality of nozzles for ejecting the one color ink, and is composed of a plurality of nozzles having a constant nozzle-to-nozzle distance (nozzle pitch) in the second direction D2. .. CMYK ink is also called color ink. Of course, the color ink that can be ejected by the print head 18 is not limited to CMYK ink. Further, the print head 18 may have a nozzle row including a plurality of nozzles for ejecting transparent ink. Transparent ink is also called clear (CL) ink. However, the nozzle row for ejecting CL ink is not necessary in all of the embodiments described later.

Each nozzle of the print head 18 is open on the facing surface of the print head 18 facing the print medium 30, and the print head 18 ejects or does not eject ink from the nozzles based on the print data. The ink ejected by the nozzle is also called an ink droplet or a dot. The print head 18 may be referred to as a print head, an inkjet head, a liquid discharge head, or the like. When the print head 18 ejects the color ink, the color image is printed on the print medium 30. The CL ink is printed so as to cover the image for the purpose of improving the gloss and water resistance of the image printed on the printing medium 30. The layer formed on the print medium 30 by the CL ink is called an overcoat layer. In addition, the overcoat is abbreviated as OC.
By rotating the take-up shaft 23 clockwise, the printed printing medium 30 conveyed by the rear drive roller 22 is taken up by the take-up shaft 23.

A delivery shaft 20, a take-up shaft 23, rollers, a motor (not shown) for appropriately rotating these, and the like are specific examples of the transport unit 16 that conveys the print medium 30. The number and arrangement of rollers provided in the middle of the transport path for transporting the print medium 30 are not limited to the mode shown in FIG. Needless to say, a flat platen or the like that supports the print medium 30 that receives the ink ejected from the print head 18 from below may be provided between the front drive roller 21 and the rear drive roller 22.

Reference numeral D1 indicates the first direction. In the example of FIG. 2, the transport direction Df and the first direction D1 are parallel between the front drive roller 21 and the rear drive roller 22. As shown in the lower part of FIG. 2, the second direction D2 intersects the first direction D1. When the first direction D1 is called the main scanning direction as described above, the second direction D2 may be called the sub-scanning direction. It may be understood that the first direction D1 and the second direction D2 are basically orthogonal to each other. In the example of FIG. 2, between the front drive roller 21 and the rear drive roller 22, a long guide rail 24 is provided above the print medium 30 in the first direction D1, and the carriage 17 is a guide rail. It is movable along 24. Of course, in order to stabilize the posture of the carriage 17, the member that supports the carriage 17 is not limited to the guide rail 24.

Further, the carriage 17 can move along the second direction D2. For example, another mechanism such as a guide rail for reciprocating the unit including the carriage 17 and the guide rail 24 along the second direction D2 is provided. Each movement of the carriage 17 along the first direction D1 and the second direction D2 is controlled by the control unit 11. That is, the carriage 17 on which the print head 18 and the color measuring unit 19 are mounted can move two-dimensionally with respect to the surface of the print medium 30. The movement of the carriage 17 along the second direction D2 corresponds to the relative movement of the carriage 17 and the print medium 30 in the second direction D2.

The operation of the print head 18 ejecting ink with the movement of the carriage 17 along the first direction D1 is called "main scanning". The main scan is also called a "path". Further, the relative movement between the carriage 17 and the print medium 30 in the second direction D2 is referred to as "sub-scanning".

2. Print color measurement processing:
FIG. 3 shows a print color measurement process according to the present embodiment by a flowchart. This print color measurement process includes a color measurement method. The print color measurement process is realized by the control unit 11 performing the process according to the program 12.

In step S100, the print data generation unit 12a acquires an image to be printed. That is, the print data generation unit 12a inputs the image data representing the image specified through the operation of the operation reception unit 14 by the user from a predetermined storage source. The image data acquired in step S100 is, for example, bitmap data in which the color of each pixel is expressed by a combination of gradation values for each RGB. The gradation value of one color is represented by, for example, 256 gradations of 0 to 255.

In step S110, the print data generation unit 12a acquires the printing conditions of the image. The print conditions are also acquired as information specified through the operation of the operation reception unit 14 by the user. Alternatively, the print condition may be information set in advance in association with the image data acquired in step S100. The printing condition is information including the paper size, the number of passes, the sub-scanning amount, and the like regarding one printing. The paper size is indicated by the paper width x the paper length. In the example of FIG. 2, the paper length is the length in the first direction D1, and the paper width is the length in the second direction D2. In the present embodiment, one printing is also referred to as one frame printing, and the paper size is also referred to as a frame size.

The number of passes is the number of passes required for printing one frame. The sub-scanning amount is the distance of the sub-scanning executed between the paths required for printing one frame.
The order of steps S100 and S110 does not have to be as shown in FIG. 3, and steps S100 and S110 may be processes to be executed substantially at the same time, or in the reverse order of the order shown in FIG. It may be a process to be executed.

In step S120, the print data generation unit 12a arranges the image according to the frame size. That is, by arranging the image data acquired in step S100 according to the frame size under the printing conditions acquired in step S110, the image data used for printing one frame is generated.

FIG. 4 is a diagram illustrating the processes of steps S100 to S140 using specific examples. Reference numeral 40 in the upper part of FIG. 4 indicates the image data acquired in step S100. The image data 40 represents a star-shaped image 44 painted in a certain color. Of course, the content of the image 44 can be arbitrarily determined by the user. The color of the image 44 may be, for example, one of the spot colors defined in advance in a color sample or the like. In the example of FIG. 4, the image data 40 is image data having a size of 13 inches in length and 9 inches in width. FIG. 4 also shows the correspondence between the image data and the directions D1 and D2.

The contents of the printing conditions acquired in step S110 are various, but here, in order to explain FIG. 4 and FIG. 5 described later, frame size = paper width 13 inches x paper length 36 inches, number of passes = 4. Suppose there is. In this case, in step S120, the print data generation unit 12a copies the image data 40 and arranges four of them in succession corresponding to the first direction D1, as shown in the middle row in FIG. Image data 41 used for printing frames is generated. In step S120, the print data generation unit 12a may enlarge or reduce the image data 40 as needed. If the image data 40 is equal to the frame size, the image data 40 = the image data 41, and step S120 is substantially unnecessary.

In step S130, the print data generation unit 12a specifies in the image data 41 the passing position through which the color measuring unit 19 passes when the final main scan for printing the image is executed. According to the above example, since the number of passes = 4, the fourth pass out of the total of four passes for printing one frame corresponds to the final main scan for printing an image. Such a final main scan is called a "final path".

The relative positional relationship between the carriage 17 and the print medium 30 in the second direction D2 at the time of the first pass for printing one frame is predetermined. Further, the number of passes and the amount of sub-scanning are known from the printing conditions acquired in step S110. Further, since the color measuring unit 19 is fixed to the carriage 17, the position of the color measuring unit 19 on the carriage 17 is also known information. Therefore, the print data generation unit 12a calculates, based on each of these pieces of information, which position on the print medium 30 the color measurement unit 19 passes through when the final pass is executed, and corresponds to the position thus determined. The position in the image data 41 to be printed is specified as a passing position.

The alternate long and short dash line in the lower part of FIG. 4 indicates the passing position in the second direction D2. In the lower part of FIG. 4, the positions of the carriage 17 and the color measuring unit 19 in the second direction D2 at the time of the final pass, which can be obtained by calculation, are illustrated by broken lines. The two-dot chain line indicating the passing position is a line parallel to the first direction D1 passing through the position of the color measuring unit 19 indicated by the broken line.

In step S140, the print data generation unit 12a synthesizes the patch 43 for color measurement at the position of the blank area that does not overlap with the image and at the passing position. According to the lower example in FIG. 4, the patch 43 is synthesized at a position corresponding to the passing position in the blank area in the image data. In FIG. 4, the image data 41 after synthesizing the patch 43 is described as the image data 42. The patch 43 is, for example, a rectangular area of the same color as the image 44. Patch 43 corresponds to the "first patch".

In step S150, the print data generation unit 12a generates print data by performing image processing on the image data 42 in which the patch 43 is combined. As one of the image processing, the print data generation unit 12a performs a color conversion processing on the image data 42. That is, the combination of the gradation values for each RGB of each pixel constituting the image data 42 is converted into the ink amount data by referring to the color conversion lookup table (hereinafter, color conversion LUT) generated in advance. As described above, if the print head 18 is a model that uses CMYK ink as the color ink, the color conversion LUT defines the correspondence between the combination of the gradation values for each RGB and the combination of the gradation values for each CMYK. It is a table that has been printed.

The print data generation unit 12a further performs halftone processing of the image data 42 after the color conversion processing. By the color conversion process, the image data 42 is in a state where each pixel has ink amount data which is a combination of gradation values for each CMYK. By the halftone processing, the image data 42 becomes print data in which ink ejection (dot on) or ink non-ejection (dot off) is defined for each pixel and each CMYK. Of course, the dot-on information in the print data may be information that defines which of a plurality of sizes of dots, such as large dots, medium dots, and small dots, is to be ejected. The halftone processing can be performed by, for example, a dither method or an error diffusion method. Such steps S100 to S150 correspond to a print data generation step of generating print data expressing an image.

In step S160, the print color measurement control unit 12b realizes printing for one frame by controlling the ink ejection by the print head 18 based on the print data. That is, the print color measurement control unit 12b prints an image on the print medium 30 by combining the pass and the sub-scanning. Specifically, the print color measurement control unit 12b decomposes the print data generated in step S150 into paths according to the print conditions. According to the above example, since the number of passes = 4, the print color measurement control unit 12b prints the print data in four partial prints used in the first pass, the second pass, the third pass, and the fourth pass, respectively. Break down into data. The partial print data means a part of the print data.

The print color measurement control unit 12b transfers the partial print data obtained by decomposing the paths to the print head 18 in the order of the corresponding paths, thereby executing ink ejection to the print head 18 based on the partial print data for each pass. Let me. In one pass, the print head 18 ejects ink from each nozzle in each nozzle row of CMYK according to the dot-on information of each CMYK in the partial print data corresponding to the pass. Further, the print color measurement control unit 12b realizes the sub-scanning by moving the carriage 17 to the second direction D2 by the amount of the sub-scanning amount of the printing condition at the timing between the passes. Further, in step S160, the print color measurement control unit 12b controls the color measurement by the color measurement unit 19. That is, the print color measurement control unit 12b causes the color measurement unit 19 to measure the color of the patch 43 printed on the print medium 30 based on the print data in the final pass. During the period of step S160, the transport unit 16 does not transport the print medium 30. That is, in step S160, the pass, the sub-scanning, and the color measurement are executed on the print medium 30 in the stationary state.

FIG. 5 is a diagram illustrating the process of step S160 by using a specific example. FIG. 5 shows the relationship between the carriage 17 and the print medium 30a corresponding to each of the first to fourth passes, so that the progress of printing according to the time transition in one step S160 can be seen. Shown. The print medium 30a is a part of the long print medium 30 shown in FIG. 2, and is a frame-sized print medium that receives printing for one frame.

In the example of FIG. 5, the carriage 17 makes an outward movement on the first and third passes, and makes a return movement on the second and fourth passes. Here, the movement of the carriage 17 in the first direction D1 is referred to as an outward movement, and the movement of the carriage 17 in the opposite direction of the first direction D1 is referred to as a return movement.
The uppermost stage in FIG. 5 shows the carriage 17 immediately before the start of the first pass. The position of the carriage 17 shown at the uppermost stage in FIG. 5 is referred to as an initial position for convenience. At this point, printing is not performed on the print medium 30a.

The second stage from the top in FIG. 5 shows the carriage 17 immediately before the start of the second pass. At this point, the result of ink ejection by the print head 18 in the first pass is formed on the print medium 30a. FIG. 5 shows how the colors of the image 44 and the patch 43 shown in FIG. 4 are gradually formed on the print medium 30a by repeating the number of passes.
The third stage from the top in FIG. 5 shows the carriage 17 immediately before the start of the third pass. At this point, the result of ink ejection by the print heads 18 of the first pass and the second pass is formed on the print medium 30a.

The lowermost part in FIG. 5 shows the carriage 17 during the return route movement of the fourth pass. At this point, in the print medium 30a, the result of ink ejection by the print heads 18 in the first to fourth passes is formed behind the carriage 17 moving in the return path in the traveling direction. At the same time, the result of ink ejection by the print heads 18 of the first to third passes is formed on the print medium 30a in front of the carriage 17 moving in the return path in the traveling direction. In FIG. 5, the patch 43p and the image 44p are the results of ink ejection by the print heads 18 in the first to fourth passes, that is, the print results completed by the color ink. The image 44p is a print result in which the image 44 as data is reproduced on the print medium 30a. The patch 43p is a print result in which the patch 43 as data is reproduced on the print medium 30a, that is, a print result of the first patch.

Although the patch 43 and the patch 43p are different in data and print result, they basically refer to the same object, and therefore, they may be simply described as the patch 43 without distinguishing them. The same applies to the relationship between the image 44 and the image 44p and the relationship between the patch 51 and the patch 51p, which will be described later. As can be seen from FIG. 5, the positional relationship between the carriage 17 and the print medium 30a in the second direction D2 differs for each pass. This is because the carriage 17 is printed at three timings: after the end of the first pass and before the start of the second pass, after the end of the second pass and before the start of the third pass, and after the end of the third pass and before the start of the fourth pass. This is because it moves to the second direction D2 according to the sub-scanning amount of the condition.

In the example of FIG. 5, since the fourth pass is the final pass, the print color measurement control unit 12b causes the color measurement unit 19 to perform color measurement during the movement period of the fourth pass. In the fourth pass, the printing of the patch 43p is completed by the ink ejection of the print head 18, and the color measuring unit 19 passes over the patch 43p, so that the color measuring unit 19 can measure the color of the patch 43p. More specifically, in the return movement of the final pass, the color measuring unit 19 is located behind the print head 18 in the traveling direction in the carriage 17. Therefore, the color measuring unit 19 can measure the color of the patch 43p immediately after the patch 43p is printed by the print head 18 during the final pass.

The color measurement unit 19 outputs the color measurement value generated by the color measurement executed in the final pass to the control unit 11. The color measuring unit 19 measures a long region parallel to the first direction D1 including the patch 43p, which is a region in the print medium 30a during the period of the final pass. The control unit 11 discards data for the color measurement values input from the color measurement unit 19 that indicate the color of the print medium 30a that is not clearly the color of the patch 43p, thereby measuring the color of the patch 43p. You can get the value.
Alternatively, when the patch 43 is combined with the image data 41 in step S140 to generate the image data 42, the position of the patch 43p in the first direction D1 is fixed. Therefore, the print color measurement control unit 12b may cause the color measurement unit 19 to perform color measurement only for a predetermined period in which the carriage 17 passes the position of the patch 43p in the final pass. The color measuring unit 19 may output the color measuring value obtained by such a temporary color measuring during the final pass period to the control unit 11 as the color measuring value of the patch 43p.
In this way, step S160 includes a printing step in which the print head 18 ejects ink based on print data, and a color measurement step in which the color measurement unit 19 mounted on the carriage 17 measures the first patch for color measurement. including.

In step S170, the print color measurement control unit 12b determines whether or not the printing to be executed is completed, and if it is completed, the determination of “Yes” ends the flowchart of FIG. On the other hand, if the printing to be executed is not completed, the process proceeds from the determination of “No” to step S180. For example, when the user has instructed to repeat printing for one frame N times, the print color measurement control unit 12b determines whether or not the instructed N times step S160 has been executed. When the instructed N times of step S160 have been executed, it is determined as "Yes" in step S170. On the other hand, when the number of times of step S160 that has been executed at the present time is less than the instructed N times, the print color measurement control unit 12b determines "No" in step S170.

In step S180, the print color measurement control unit 12b performs transfer and sub-scanning for printing the next one frame. That is, the print color measurement control unit 12b controls the transport unit 16 to transport the print medium 30 downstream by the length of the frame-sized paper. Further, the print color measurement control unit 12b moves the carriage 17 in the state where the final pass is completed in the opposite direction of the second direction D2 and returns it to the initial position. Of course, in the process of returning the carriage 17 to the initial position, the carriage 17 is moved in parallel with the first direction D1 if necessary. By returning to step S160 through such step S180, the print color measurement control unit 12b again executes printing for one frame in step S160 using the print data generated in step S150.

3. 3. Error handling according to the evaluation of color measurement values:
FIG. 6 is a flowchart of print color measurement processing including error processing according to the evaluation of the color measurement value. FIG. 6 is different from the flowchart of FIG. 3 in that it has steps S162 and S163. The description of FIG. 6 that is common to the flowchart of FIG. 3 will be omitted.

In step S162, the control unit 11 evaluates whether or not the color measurement value of the first patch acquired by the color measurement of the final path in step S160 is normal. Although the evaluation method is not limited, for example, the control unit 11 compares the color measurement value of the first patch with a predetermined reference value ideal as the color measurement value of the first patch, and determines the color difference between the two values. If it is within the color difference of, it is regarded as normal, and if the color difference of both values exceeds the predetermined color difference, it is regarded as abnormal. If the color measurement value of the first patch is normal, the process proceeds from the determination of "Yes" in step S162 to step S170, and if the color measurement value of the first patch is abnormal, the determination of "No" in step S162 is followed by a step. Proceed to S163.

In step S163, the control unit 11 executes error processing and ends the flowchart of FIG. The error processing is, for example, a process of stopping an operation related to printing. That is, since the color of the print result is abnormal, the control unit 11 stops driving the transport unit 16, the carriage 17, and the print head 18 to end the flowchart of the print color measurement process. Thereby, for example, it is possible to prevent the image 44 from being further printed in an inappropriate color. Further, as one of the error processing, the control unit 11 may display a warning screen for notifying the user that the color of the print result is abnormal on the display unit 13.

The determination in step S162 may be performed during step S160 rather than after step S160. That is, when the control unit 11 obtains the color measurement value of the first patch by the color measurement of the final path in step S160, the control unit 11 executes the determination of step S162 during the execution of the final path, and the color measurement value of the first patch. If is abnormal, the process immediately proceeds to step S163. As a result, if the color measurement value of the first patch is abnormal, the drive of the carriage 17 and the print head 18 can be stopped before the final pass is completed to stop the wasteful consumption of ink as soon as possible. can.

4. Modification example of patch composite image:
FIG. 7A shows an example of image data 45 having a frame size generated by the print data generation unit 12a by the processing up to step S140. The print data generation unit 12a may generate the image data 45 as the image data used for printing one frame, as in the case of generating the image data 42 shown in FIG. The image data 45 is image data in which the image 44 and the image 46 having a color different from the image 44 are arranged according to the frame size. The image 46 is also an image to be printed specified by the user in the same manner as the image 44.

Further, the image data 45 is a position of a blank area that does not overlap with either the image 44 or the image 46, and the color measurement patch 43 and the color measurement patch 47 are respectively combined at the above-mentioned passing position. This is the generated image data. As described above, the patch 43 is a patch of the same color as the image 44. The patch 47 is a patch having the same color as the image 46. Patch 47 also corresponds to the "first patch" like patch 43. In this way, the image data 45 obtained by synthesizing the plurality of first patches of different colors at the passing positions is targeted for the image processing in step S150, and in step S160, the patch 43 printed on the print medium 30. And the patch 47 is color-measured by the color-measuring unit 19 in the final pass. Of course, in step S162, the control unit 11 can determine whether or not the color measurement values of the printed patch 43 and the patch 47 are normal. Then, the control unit 11 can perform error processing (step S163) if at least one of the color measurement values of the patch 43 and the patch 47 is abnormal.

FIG. 7B shows an example of image data 48 having a frame size generated by the print data generation unit 12a by the processing up to step S140. The print data generation unit 12a may generate the image data 48 as the image data used for printing one frame, as in the case of generating the image data 42 shown in FIG. 4 and the image data 45 shown in FIG. 7A. The image data 48 differs from the image data 45 in that it has a specific mark 49 that triggers the color measurement of the first patch. Regarding the explanation of the image data 48, it is not important that there are a plurality of images to be printed and the first patch as in the image data 45, and the image to be printed and the first patch as in the image data 42 are There may be one for each.

In step S140, the print data generation unit 12a synthesizes the first patch, which is a patch for color measurement, into the blank area of the image, and at the position of the blank area, the first patch is in the traveling direction of the carriage 17 of the final path. Mark 49 is synthesized at a position before one patch. The mark 49 may be a mark whose color or the like is predetermined as different from the patch for color measurement. In the example of FIG. 7B, the mark 49 is a black patch. According to the above example, the carriage 17 for printing one frame with the number of passes = 4 moves on the return path in the final pass. Therefore, the print data generation unit 12a generates the image data 48 by synthesizing the patch 49 at the above-mentioned passing position in the blank area and at a position before the first patch in the traveling direction of the return path movement.

By targeting such image data 48 for image processing in step S150, in step S160, the mark 49 printed on the print medium 30 precedes the patch 43 and patch 47 printed on the print medium 30. The color is measured by the color measuring unit 19 in the final pass. In such a configuration, the print color measurement control unit 12b measures that the color of the first patch should be measured in the main scan when the color measurement unit 19 detects the mark 49 printed on the print medium 30 based on the print data. Instruct the color unit 19. Upon receiving the instruction, the color measuring unit 19 continuously executes the color measurement while the carriage 17 is moving in step S160, and when the mark 49 can be detected from the color measurement value, the current path is the final path. Recognize that there is. Then, the color measuring unit 19 measures the colors of the patch 43 and the patch 47 printed on the print medium 30 in the recognized final pass.

The difference between the color measurement after the mark 49 is detected and the color measurement before the mark 49 is detected is, for example, whether or not the color measurement value is output to the control unit 11. That is, the color measurement unit 19 does not output the color measurement value to the control unit 11 in the color measurement until the mark 49 is detected, and when the mark 49 is detected, the color measurement unit 19 obtains the color measurement during the period of the pass at that time. The color measurement value may be output to the control unit 11. As a result, the control unit 11 can obtain the color measurement value of the first patch that the color measurement unit 19 measures the color in the final path.

5. Print color measurement processing including printing of OC layer:
FIG. 8 is a flowchart of a print color measurement process including printing of the OC layer. Regarding FIG. 8, the description of the contents common to the flowchart of FIG. 3 will be omitted as appropriate. In the flowchart of FIG. 8, steps S131, S141, S151, and S161 are performed in place of steps S130, S140, S150, and S160 of the flowchart of FIG.

Regarding the description of FIGS. 8 and 9 and 10 described later, according to the printing conditions acquired in step S110, frame size = paper width 13 inches x paper length 36 inches, number of passes = 4 times of color ink + 2 times of CL ink. , Suppose. The frame size is the same as the previous description. "Number of passes = 4 times of color ink + 2 times of CL ink" is 1 in a total of 6 passes by executing the pass of ejecting color ink 4 times and then executing the pass of ejecting CL ink twice. It means printing for frames. The four passes for ejecting the color ink may be understood to be the same as the first to fourth passes described with reference to FIG. 5, except that the “patch 51” described later is printed. The OC layer is printed by two passes of ejecting CL ink, that is, the fifth pass and the sixth pass. Of course, the printing conditions acquired in step S110 also include information on the sub-scanning amount between the 4th and 5th passes and the sub-scanning amount between the 5th and 6th passes.

In step S131, the print data generation unit 12a specifies in the image data the passing position through which the color measuring unit 19 passes when the final pass is executed, as in step S130. The final pass is the last pass, that is, the fourth pass in the pass in which the color ink is ejected to print one frame of the image as before. The end of a total of 6 passes including the pass for ejecting CL ink is not called the final pass. When the number of passes for ejecting color ink to print an image for one frame is called the "first predetermined number of times", the final pass corresponds to the last main scan of the first predetermined number of times. Incidentally, the number of passes for ejecting CL ink after the first predetermined number of passes in printing for one frame is referred to as "second predetermined number of passes".

In step S131, the print data generation unit 12a further specifies in the image data the passing position through which the color measuring unit 19 passes when the OC specific path is executed. The “OC specific pass” means a specific pass among the second predetermined number of passes for ejecting CL ink, and here, among the above-mentioned 5th pass and 6th pass, the preceding 5th pass Is the OC specific path. The print data generation unit 12a calculates which position on the print medium 30 the color measuring unit 19 passes when the OC specific path is executed, and determines the position in the image data corresponding to the position obtained in this way. It is specified as the passing position of the color measuring unit 19 at the time of the OC specific pass.

FIG. 9 is a diagram illustrating the processing of steps S131 and S141 with reference to specific examples. FIG. 9 may be viewed in the same manner as the description corresponding to steps S130 and S140 in FIG. The image data 50 shown in FIG. 9 is different from the image data 42 shown in FIG. 4 only in that the patch 51 for color measurement is combined. The two-dot chain line in FIG. 9 indicates the passing position through which the color measuring unit 19 passes during the final pass, similarly to the two-dot chain line in FIG.

In FIG. 9, the number in parentheses for the carriage 17 represented by the broken line indicates the number of the path corresponding to the position of the carriage 17 in the second direction D2 in the total of six passes. .. In the example of FIG. 9, the position of the carriage 17 in the second direction D2 at the time of the fourth pass, that is, the final pass, and the position of the carriage 17 in the second direction D2 at the time of executing the sixth pass are the same. Further, in the example of FIG. 9, the carriage 17 at the time of executing the fifth pass, that is, the OC specific pass, moves in the opposite direction of the second direction D2 from the time of the final pass. In FIG. 9, the alternate long and short dash line parallel to the first direction D1 indicates the passing position through which the color measuring unit 19 passes when the OC specific path is executed.

In step S141, the print data generation unit 12a synthesizes the patch 43 at the position of the blank area that does not overlap with the image and the patch 43 passes through the color measuring unit 19 when the final pass is executed, and at the position of the blank area. Therefore, the image data of the frame size is generated by synthesizing the patch 51 at the passing position through which the color measuring unit 19 passes when the OC specific path is executed. In FIG. 9, the image data 41 (see FIG. 4) after the patch 43 and the patch 51 are combined as described above in the blank area that does not overlap with the image 44 is described as the image data 50. The patch 51 is a rectangular area having the same color as the image 44, like the patch 43. That is, in the image data 50, the patch 51 is an area of the same color as the patch 43, and the patch 51 corresponds to the “second patch”.

In step S151, the print data generation unit 12a generates print data by performing image processing on the image data 50 in which the patch 43 and the patch 51 are combined. The print data generated from the image data 50, that is, the print data in which dot-on or dot-off is defined for each CMYK for each pixel of the image data 50, corresponds to the color ink data expressing the image 44, the patch 43, and the patch 51. Further, in step S151, the print data generation unit 12a generates CL ink data in response to the instruction to execute the path for ejecting CL ink under the printing conditions.

The CL ink data is image data having a frame size in which dot-on or dot-off of CL ink is defined for each pixel. The details of the CL ink data are not particularly limited, but for example, it is image data in which dot-on of CL ink is defined for all pixels or almost all pixels. Alternatively, the CL ink data is image data in which the dot-on of the CL ink is defined for the pixels in the region overlapping the image 44, the patch 43, and the patch 51 in the color ink data when superimposed on the color ink data. Such CL ink data represents the OC layer to be printed. The color ink data and CL ink data generated in step S151 may be collectively referred to as print data.

In step S161, the print color measurement control unit 12b prints one frame on the print medium 30 based on the print data by combining the pass and the sub-scanning. The printing procedure in which the color ink data, which is the print data, is decomposed into paths corresponding to each of the first to fourth passes is as described in step S160. Further, the print color measurement control unit 12b decomposes the CL ink data in the print data into partial print data used in each of the 5th and 6th passes, and decomposes each partial print data into partial print data. The data is transferred to the print head 18 in the order of the corresponding paths. As a result, the print head 18 executes CL ink ejection based on the partial print data for each pass in each of the 5th pass and the 6th pass. Of course, the print color measurement control unit 12b realizes the sub-scanning by moving the carriage 17 along the second direction D2 according to the sub-scanning amount of the printing conditions at the timing between the passes.

Further, in step S161, the print color measurement control unit 12b causes the color measurement unit 19 to measure the color of the patch 43 or patch 51 printed on the print medium 30 based on the print data in a plurality of passes including the final pass. Similar to step S160, the transport unit 16 does not transport the print medium 30 during the period of step S161.

FIG. 10 is a diagram illustrating the process of step S161 by using a specific example. FIG. 10 may be viewed in the same manner as in FIG. As can be seen from the above description, the first to fourth passes of step S161 are different from the first to fourth passes of step S160 in that the patch 51 is printed on the print medium 30a. In FIG. 10, the description of the first pass is the same as in FIG. 5, and is omitted. FIG. 10 shows how the colors of the image 44, the patch 43, and the patch 51 shown in FIG. 9 are gradually formed on the print medium 30a by repeating the number of passes. The patch 51p is a print result in which the patch 51 as data is reproduced on the print medium 30a, that is, a print result of the second patch. Similar to step S160, the print color measurement control unit 12b causes the color measurement unit 19 to measure the color of the patch 43p in the fourth pass, which is the final pass.

The fourth stage from the top in FIG. 10 shows the carriage 17 immediately before the start of the fifth pass, which is the outward movement. At this point, printing of the image 44, the patch 43, and the patch 51 based on the color ink data in the first to fourth passes is completed on the print medium 30a. In the fifth pass, the print color measurement control unit 12b forms a part of the OC layer on the print medium 30a by causing the print head 18 to eject CL ink based on the CL ink data. In addition, in the fifth pass, which is the OC specific pass, the print color measurement control unit 12b causes the color measurement unit 19 to perform color measurement. That is, since the color measuring unit 19 passes over the patch 51p in the 5th pass, the color measuring unit 19 can measure the color of the patch 51p by performing the color measurement in the period of the 5th pass.

At the bottom of FIG. 10, the carriage 17 immediately before the start of the sixth pass, which is the return route movement, is shown. At this point, the ink ejection up to the fifth pass is completed. In the sixth pass, the print color measurement control unit 12b forms the remaining OC layer on the print medium 30a by causing the print head 18 to eject CL ink based on the CL ink data. In addition, in the sixth pass, the print color measurement control unit 12b causes the color measurement unit 19 to perform color measurement. As described above, in the present embodiment, the position of the carriage 17 on the fourth pass, which is the final pass, in the second direction D2 and the position of the carriage 17 on the sixth pass in the second direction D2 are the same. Therefore, since the color measuring unit 19 passes over the patch 43p in the 6th pass, the color measuring unit 19 can measure the color of the patch 43p by performing the color measurement in the period of the 6th pass.

However, since the patch 43p has already been color-measured in the fourth pass, which is the final pass, the print color measurement control unit 12b omits having the color measurement unit 19 measure the color of the patch 43p again in the sixth pass. May be good.
Further, the present embodiment also includes a mode in which the patch 51 is not printed out of the patch 43 and the patch 51, and the color measurement of the patch 43 is performed in each of the two passes.

The color measurement unit 19 outputs the color measurement value generated by the color measurement executed in each of the plurality of passes including the final pass to the control unit 11. The patch 43 and the patch 51 in the image data 50 are both generated in the same color as the image 44. Therefore, the control unit 11 may calculate the average value of the color measurement values of the patches measured by the color measurement unit 19 in each of the plurality of passes including the final pass, and acquire this average value as the patch color. .. That is, when the control unit 11 inputs the color measurement values of the patch 43p twice and the color measurement values of the patch 51p from the color measurement unit 19 by the color measurement of each of the 4th pass, the 5th pass, and the 6th pass. Calculates the average value of these three color measurement values. Alternatively, when the color measurement value of the patch 43p and the color measurement value of the patch 51p are input from the color measurement unit 19 by the color measurement of the 4th pass and the 5th pass, the average value of the two color measurement values is calculated. calculate. Alternatively, when the color measurement values of the patch 43p are input twice from the color measurement unit 19 by the color measurement of each of the 4th pass and the 6th pass, the average value of the color measurement values for those two times is calculated.

In the flowchart of FIG. 8, the control unit 11 can naturally execute the determination of step S162 shown in FIG. 6 after step S161 or in the middle of step S161, and execute step S163 according to the determination result. .. Further, also in the flowchart of FIG. 8, as shown in FIG. 7A, a plurality of first patches having different colors may be printed at the passing position through which the color measuring unit 19 passes in the final pass, and is shown in FIG. 7B. Similarly, the mark 49 that triggers the patch color measurement of the final pass may be printed.

6. summary:
As described above, according to the present embodiment, the printing apparatus 10 includes a printing head 18 that ejects ink to the printing medium 30, a color measuring unit 19 that measures colors, and a printing head 18 and a color measuring unit 19. A carriage 17 that moves along the first direction D1 is provided. Then, the main scan in which the print head 18 ejects ink with the movement of the carriage 17 along the first direction D1 and the relative movement of the carriage 17 and the print medium 30 in the second direction D2 intersecting the first direction D1. The image is printed on the printing medium 30 by the combination of. Such a printing device 10 has a print data generation unit 12a that generates print data expressing an image, and a print color measurement control that controls ink ejection by the print head 18 based on the print data and color measurement by the color measurement unit 19. A part 12b and a part 12b are provided. The print data generation unit 12a synthesizes the first patch for color measurement at the position of the blank area that does not overlap with the image and at the position where the color measurement unit 19 passes when the final main scan for printing the image is executed. The print data is generated, and the print color measurement control unit 12b causes the color measurement unit 19 to measure the color of the first patch printed on the print medium 30 based on the print data in the final main scan.

According to the above configuration, the printing apparatus 10 synthesizes and prints the first patch at the passing position through which the color measuring unit 19 passes when the final main scanning is executed. Therefore, regardless of the number of times or the amount of sub-scanning for printing an image, the passing position can be specified based on such printing conditions to obtain the printing conditions. Regardless of the difference, the first patch printed by the print head 18 mounted on the carriage 17 can be reliably measured by the color measuring unit 19 mounted on the carriage 17. As a result, the positional relationship between the color measuring camera mounted on the carriage and the print medium is not constant, so it is essentially unnecessary to enable the color measuring camera to measure the color of the patch under any printing conditions. It solves the problem of having to print patches in a large size. Further, since the color measuring unit 19 measures the color of the first patch when the final main scanning is executed, the time from printing to the color measuring can be shortened as much as possible. This can contribute to the reduction of waste of ink, print medium, and time.

Further, according to the present embodiment, the print data includes color ink data representing an image using color ink and a first patch, and CL ink data representing an OC layer using CL ink. The print color measurement control unit 12b has a first predetermined number of main scans for ejecting color ink based on the color ink data, and a second main scan for ejecting CL ink based on the CL ink data after the first predetermined number of main scans. By causing the print head 18 to perform a predetermined number of main scans, the image, the first patch, and the OC layer are printed on the print medium 30, and the first patch printed on the print medium 30 based on the color ink data is printed. In the final main scan of the first predetermined number of times, the color measuring unit 19 is made to measure the color.

According to the above configuration, the printing apparatus 10 prints the first patch in the final main scan for ejecting the color ink even when the OC layer with the CL ink is overlaid and printed after printing the image with the color ink. Let the color measuring unit 19 measure the color. That is, by measuring the color of the first patch before executing the main scan for ejecting the CL ink, it is possible to shorten the time from the printing of the first patch to the color measurement.

Further, according to the present embodiment, the print color measurement control unit 12b sends the color measurement unit 19 to the color measurement unit 19 in the main scan when the color measurement unit 19 passes through the position of the first patch in the second predetermined number of main scans. The color of the first patch may be measured, and the average value of the color measurement values obtained by the color measurement of the first patch may be calculated.
According to the above configuration, the printing apparatus 10 has a first main scan of a predetermined number of times and a main scan in which the color measuring unit 19 passes through the position of the first patch in the second predetermined number of main scans, respectively. In, the color measuring unit 19 measures the color of the first patch, and calculates the average value of the color measurement values of the first patch. As a result, it is possible to suppress the variation in color measurement and acquire the color of the first patch with higher accuracy.

Further, according to the present embodiment, the print data generation unit 12a is located at the position of the blank area and at the position where the color measuring unit 19 passes when the specific main scan of the second predetermined number of main scans is executed. , A color ink data obtained by synthesizing a second patch for color measurement of the same color as the first patch is generated, and the print color measurement control unit 12b prints the second patch printed on the print medium 30 based on the color ink data. The color measurement unit 19 is made to measure the color in a specific main scan, and the average value of the color measurement value obtained by the color measurement of the first patch and the color measurement value obtained by the color measurement of the second patch is calculated. May be.
According to the above configuration, the printing apparatus 10 causes the color measuring unit 19 to measure the color of the first patch in the final main scan of the first predetermined number of times, and also causes the color measuring unit 19 to measure the color of the first patch, and a specific main scan of the second predetermined number of main scans. That is, the color measuring unit 19 can measure the color of the second patch in the OC specific path. Further, it is possible to suppress the variation in color measurement and acquire the color of the first patch with higher accuracy.

Further, according to the present embodiment, the print data generation unit 12a synthesizes a specific mark at the position of the blank area and at a position before the first patch in the traveling direction of the carriage 17 of the last main scan. The print data may be generated, and the color measurement unit 19 may measure the color of the first patch in the main scan when the specific mark printed on the print medium 30 is detected based on the print data.
According to the above configuration, even if the print color measurement control unit 12b does not notify the color measurement unit 19 of the timing of the last main scan, the color measurement unit 19 itself determines the timing of the main scan for measuring the color of the first patch. You can judge.

Further, in the present embodiment, the print head 18 mounted on the carriage 17 ejects ink to the print medium 30 as the carriage 17 moves along the first direction D1, and the second direction intersects the first direction D1. A color measurement method by a printing apparatus 10 for printing an image on a printing medium 30 by a combination of a relative movement of a carriage 17 and a printing medium 30 in D2 is disclosed. The color measurement method includes a print data generation step of generating print data expressing an image, a printing step in which the print head 18 ejects ink based on the print data, and a color measurement unit 19 mounted on the carriage 17 for color measurement. It is provided with a color measurement step of measuring the color of the first patch of the above. In the color measurement method, the print data generation step synthesizes the first patch at the position of the blank area that does not overlap with the image and at the position where the color measurement unit 19 passes when the final main scan for printing the image is executed. The color measurement step of generating print data and measuring the color of the first patch printed on the print medium 30 based on the print data by the print process is performed in the final main scan.

7. Other explanation:
In order for the color measuring unit 19 to measure the color of the patch for color measurement immediately after printing in the final pass, the color measuring unit 19 needs to be located behind the print head 18 in the traveling direction of the carriage 17 in the final pass. .. According to the examples shown in FIGS. 2 and 5, the color measuring unit 19 mounted on the carriage 17 is located behind the print head 18 in the traveling direction when the carriage 17 is moved on the return path. Therefore, assuming such an example, the print color measurement control unit 12b controls the movement of the carriage 17 so that the final path is the return path movement in step S160 and step S161. For example, if the number of passes for ejecting color ink is specified as 5 in the printing conditions acquired in step S110, the print color measurement control unit 12b sets the first pass as the return path to make the final pass. The fifth pass is the return trip.

5 and 10 show bidirectional printing in which ink is ejected in both the outward movement and the return movement of the carriage 17, but the print head 18 uses only one of the outward movement and the return movement. Unidirectional printing that ejects ink may be performed. In the case of unidirectional printing, the movement that does not eject ink among the outward movement and the return movement is called an empty pass. Assuming unidirectional printing, empty passes are not included in the number of passes under the printing conditions. If the color measuring unit 19 is located behind the print head 18 in the traveling direction when the carriage 17 is moved on the return path as in the examples of FIGS. 2 and 5, the print color measuring control unit 12b may be used. The print head 18 may execute unidirectional printing in which ink is ejected on the return trip.

The sub-scanning, which is the relative movement of the carriage 17 and the print medium 30 in the second direction D2, may be realized by transporting the print medium 30 instead of moving the carriage 17 along the second direction D2. That is, the transport direction Df of the print medium 30 by the transport unit 16 may not be in a direction parallel to the first direction D1 as shown in FIG. 2, but may be in a direction parallel to the second direction D2. In this case, the transport unit 16 may transport the print medium 30 between the passes according to the amount of sub-scanning.
The print medium 30 is not limited to a long medium such as roll paper, and may be a cut sheet paper or the like that has been cut in advance on a page-by-page basis.

10 ... printing device, 11 ... control unit, 11a ... CPU, 11b ... ROM, 11c ... RAM, 12 ... program, 12a ... print data generation unit, 12b ... print color measurement control unit, 16 ... transport unit, 17 ... carriage, 18 ... print head, 19 ... color measuring unit, 30, 30a ... print medium, 42 ... image data, 43 ... (first) patch, 44 ... image, 49 ... mark, 50 ... image data, 51 ... (second) patch

Claims (6)

A print head that ejects ink to the print medium,
The color measuring unit that performs color measurement and
A carriage equipped with the print head and the color measuring unit and moving along the first direction is provided.
A combination of a main scan in which the print head ejects ink as the carriage moves along the first direction, and a relative movement of the carriage and the print medium in a second direction intersecting the first direction. A printing device that prints an image on the printing medium.
A print data generation unit that generates print data that expresses the image, and
A print color measurement control unit that controls ink ejection by the print head and color measurement by the color measurement unit based on the print data is provided.
The print data generation unit applies a first patch for color measurement at a position of a blank area that does not overlap with the image and at a position where the color measurement unit passes when the final main scan for printing the image is executed. Generate the synthesized print data and generate
The print color measurement control unit is a printing apparatus characterized in that the color measurement unit measures the color of the first patch printed on the print medium based on the print data in the final main scan. The print data includes color ink data representing the image and the first patch with color ink, and transparent ink data representing an overcoat layer with transparent ink.
The print color measurement control unit performs a first predetermined number of main scans for ejecting the color ink based on the color ink data, and after the first predetermined number of main scans, the transparent ink based on the transparent ink data. The image, the first patch, and the overcoat layer are printed on the print medium by causing the print head to perform a second main scan for ejecting the ink, and based on the color ink data. The printing apparatus according to claim 1, wherein the color measuring unit is made to measure the color of the first patch printed on the printing medium in the final main scan of the first predetermined number of times. The print color measurement control unit measures the color of the first patch on the color measurement unit in the main scan when the color measurement unit passes the position of the first patch in the second predetermined number of main scans. The printing apparatus according to claim 2, wherein an average value of color measurement values obtained by performing color measurement of the first patch a plurality of times is calculated. The print data generation unit has the same color as the first patch at the position of the blank area and at the position where the color measuring unit passes when a specific main scan of the second predetermined number of main scans is executed. The color ink data obtained by synthesizing the second patch for color measurement of
The print color measurement control unit causes the color measurement unit to measure the color of the second patch printed on the print medium based on the color ink data in the specific main scan, and measures the first patch a plurality of times. The printing apparatus according to claim 3, wherein an average value of a color measurement value obtained by color and a color measurement value obtained by color measurement of the second patch is calculated. The print data generation unit generates the print data in which a specific mark is synthesized at a position in the blank area and in front of the first patch in the traveling direction of the carriage in the last main scan.
Claims 1 to 1, wherein the color measuring unit measures the color of the first patch in a main scan when the specific mark printed on the print medium is detected based on the print data. Item 4. The printing apparatus according to any one of Items 4. The main scan in which the print head mounted on the carriage ejects ink to the print medium as the carriage moves along the first direction, and the relative relationship between the carriage and the print medium in the second direction intersecting the first direction. It is a color measurement method by a printing device that prints an image on the printing medium by a combination of movement and movement.
A print data generation process for generating print data expressing the image, and
A printing process in which the print head ejects ink based on the print data,
The color measuring unit mounted on the carriage includes a color measuring step of measuring the color of the first patch for color measuring.
In the print data generation step, the first patch is synthesized at a position of a blank area that does not overlap with the image and at a position where the color measuring unit passes when the final main scan for printing the image is executed. Generate print data
A color measuring method characterized in that the color measuring step of measuring the color of the first patch printed on the printing medium based on the printing data by the printing step is performed in the final main scan.

Images