Printing apparatus and printing method

Abstract

The present invention relates to a printing device and a printing method. A suitable test pattern for properly performing reading, post-reading inspection is provided. The printing device is provided with a print head having nozzles that eject dots of a first size that are dots of ink and dots of a second size that are smaller than the first size, and a control section that, by controlling the print head, prints a test pattern for inspecting a state of ink ejection of the nozzles on a print medium, the test pattern having a first pattern element formed of a plurality of dots of the first size and a second pattern element formed of a plurality of dots of the second size, the control section causing the print head to print the test pattern in which the number of dots of the second size forming the second pattern element is larger than the number of dots of the first size forming the first pattern element.

Description

TECHNICAL FIELD

[0001] The present application relates to a printing apparatus and a printing method. BACKGROUND

[0002] There is disclosed a technique as follows: a printing apparatus of an inkjet type records a test pattern on a printing sheet by a recording head, reads the test pattern by a scanner, interpolates the read data, and determines abnormality of a nozzle based on the interpolated read data (see Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-54970

[0004] However, in a case where a test pattern is printed on a printing medium by a head capable of ejecting dots of a plurality of sizes from a nozzle, the density difference with respect to a portion in the test pattern printed by a dot of a smaller size among the plurality of sizes from the nozzle and the printing medium sometimes becomes small. As a result, sometimes a part of reading of the test pattern required for checking of the nozzle and checking based on the read data cannot be properly performed. Therefore, a proper test pattern is required in order to properly perform reading and checking after reading. SUMMARY

[0005] The printing apparatus includes a printing head having a nozzle that ejects a dot of a first size of a dot of ink and a dot of a second size smaller than the first size, and a control section that causes the printing head to print a test pattern for checking a state of ink ejection of the nozzle on a printing medium, the test pattern having a first pattern element formed of a plurality of dots of the first size and a second pattern element formed of a plurality of dots of the second size, and that causes the printing head to print the test pattern in which the number of dots of the second size forming the second pattern element is larger than the number of dots of the first size forming the first pattern element.

[0006] The printing method includes a printing process of printing a test pattern on a printing medium using a printing head having a nozzle that ejects a dot of a first size of a dot of ink and a dot of a second size smaller than the first size, the test pattern being for checking a state of ink ejection of the nozzle, the test pattern having a first pattern element formed of a plurality of dots of the first size and a second pattern element formed of a plurality of dots of the second size, and in the printing process, the test pattern is printed in which the number of dots of the second size forming the second pattern element is larger than the number of dots of the first size forming the first pattern element. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1is a block diagram simply showing the configuration of the device.

[0008] Figure 2 is a diagram showing a specific example of the configuration including the conveyance section, the print head.

[0009] Figure 3 is a diagram showing the relationship of the print medium and the print head based on a viewpoint of viewing from above.

[0010] Figure 4 is a flowchart showing the flow of the inspection from the printing of the TP to the nozzle.

[0011] Figure 5 is a diagram showing an example of the TP image data.

[0012] Figure 6 is a diagram showing a part of the TP enlarged.

[0013] Figure 7 is a diagram showing an example of the different size dot number table.

[0014] Explanation of Reference Numerals

[0015] 10... printing device; 11... control section; 11a... CPU; 11b... ROM; 11c... RAM; 12... program; 12a... print control section; 12b... reading control section; 12c... inspection section; 16... conveyance section; 17... carriage; 18... print head; 19... reading section; 21... nozzle; 26, 26C, 26LC, 26M, 26LM, 26Y, 26K... nozzle row; 30... print medium; 40... TP image data; 41, 41CL, 41CS, 41ML, 41MS, 41YL, 41YS, 41KL, 41KS... TP; 42CL, 42CS... pattern element; 50: different size dot number table. DETAILED DESCRIPTION

[0016] Hereinafter, the embodiments of the present application will be described with reference to the drawings. Note that each drawing is merely an example for describing the present embodiment. Since each drawing is an example, there are cases where the ratio, shape is incorrect, or mutually mismatched, or a part is omitted.

[0017] 1. Device Configuration:

[0018] Figure 1 The configuration of the printing device 10 to which the present embodiment is applied is simply shown.

[0019] The printing device 10 has a control section 11, a display section 13, an operation reception section 14, a communication IF 15, a conveyance section 16, a carriage 17, a print head 18, a reading section 19, and the like. IF is an abbreviation of interface. The control section 11 is configured to include one or more ICs including a CPU 11a as a processor, a ROM 11b, a RAM 11c, and the like, other nonvolatile memories, and the like.

[0020] In the control section 11, the processor, that is, the CPU 11a executes arithmetic processing based on one or more programs 12 stored in the ROM 11b, other memories, and the like, using the RAM 11c and the like as a work area, thereby realizing various functions of a print control section 12a, a reading control section 12b, a checking section 12c, and the like. Note that the processor is not limited to one CPU, and can be configured to perform processing by a plurality of CPUs, hardware circuits such as ASICs, or can be configured to perform processing in cooperation with hardware circuits.

[0021] The display section 13 is a unit for displaying visual information, and is configured by, for example, a liquid crystal display, an organic EL display, or the like. The display section 13 can also be configured to include a display and a drive circuit for driving the display. The operation reception section 14 is a unit for receiving an operation of 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 can also be realized as a function of the display section 13.

[0022] The display section 13 and the operation reception section 14 can be part of the configuration of the printing device 10, but can also be a peripheral device external to the printing device 10. The communication IF 15 is a general term for one or more IFs of the printing device 10 for connecting to the outside in a wired or wireless manner in accordance with a communication protocol prescribed by a known communication standard.

[0023] The conveyance section 16 is a unit for conveying a print medium, and includes a roller, a motor that rotates the roller, and the like. The print head 18 performs printing by ejecting ink from a nozzle toward a print medium in an inkjet manner. The reading section 19 is a unit that reads a print result on a print medium. The reading section 19 is also referred to as a scanner. However, the printing device 10 can also be configured not to include the reading section 19.

[0024] The carriage 17 is a mechanism that can move in a prescribed direction in a reciprocating manner by receiving power of a carriage motor not shown. The prescribed direction in which the carriage 17 moves is also referred to as a main scanning direction. As shown in FIG. 1, the carriage 17 is mounted with the print head 18. Figure 2 、 Figure 3

[0025] Figure 1 The configuration of the printing device 10 shown in FIG. 1 can be realized by one printer, or can be realized by a plurality of devices connected in a communicable manner.​

[0026] That is, the printing device 10 can be a printing system 10 as an actual form. The printing system 10 includes, for example, an information processing device that functions as the control section 11, and a printer that includes the conveyance section 16, the carriage 17, the print head 18, and the reading section 19. The printing method of the present embodiment is implemented by such a printing device 10 or printing system 10.

[0027] Further, the portion of the control section 11 that functions as the print control section 12a and the portion that functions as the reading control section 12b and the inspection section 12c can also be separate information processing devices.

[0028] Figure 2 A specific example of the printing device 10 is shown, which mainly includes the configuration of the conveyance section 16, the print head 18. In Figure 2 In the specific example, the view is shown from a viewpoint orthogonal to the conveyance direction D2 of the print medium 30.

[0029] The conveyance section 16 has a feed-out shaft 22 at the upstream of conveyance, and has a winding shaft 25 at the downstream of conveyance. The upstream and downstream of conveyance are simply referred to as the upstream and downstream. The long strip-shaped print medium 30 wound in a roll shape on the feed-out shaft 22 and the winding shaft 25 is erected along the conveyance direction D2. The print medium 30 is conveyed in the conveyance direction D2. The print medium 30 can be paper, and can also be a medium of a material other than paper.

[0030] In the example of Figure 2 The print medium 30 wound on the feed-out shaft 22 is fed downstream by the clockwise rotation of the feed-out shaft 22. A front drive roller 23 is provided at a position downstream of the feed-out shaft 22, and a rear drive roller 24 is provided at a position upstream of the winding shaft 25. The print medium 30 fed from the feed-out shaft 22 is conveyed downstream by the clockwise rotation of the front drive roller 23. A nip roller 23n is provided with respect to the front drive roller 23. The print medium 30 is nipped between the nip roller 23n and the front drive roller 23 by the abutment of the nip roller 23n against the print medium 30.

[0031] The print medium 30 conveyed downstream by the front drive roller 23 is further conveyed downstream by the clockwise rotation of the rear drive roller 24. A nip roller 24n is provided with respect to the rear drive roller 24. The print medium 30 is nipped between the nip roller 24n and the rear drive roller 24 by the abutment of the nip roller 24n against the print medium 30.

[0032] Between the front drive roller 23 and the rear drive roller 24, the print head 18 that ejects ink onto the print medium 30 from the upper side is arranged. According to Figure 2As is apparent, the print head 18 is mounted on the carriage 17. The print head 18 is capable of ejecting ink of a plurality of colors such as cyan (C), magenta (M), yellow (Y), black (K), light cyan (LC), and light magenta (LM).

[0033] The print head 18 has nozzles each of which opens on a nozzle face 20 of the print head 18 opposite the print medium 30, and the print head 18 ejects or does not eject ink from the nozzles based on print data. The ink ejected from the nozzles is referred to as a droplet, or also as a dot. The print head 18 can also be referred to as a character printing head, an inkjet head, a liquid ejection head, a recording head, or the like.

[0034] The printed print medium 30 conveyed by the rear drive roller 24 is wound on the winding shaft 25 by the clockwise rotation of the winding shaft 25.

[0035] The feed shaft 22, the winding shaft 25, the rollers, a motor or the like not shown for appropriately rotating these, and the like are specific examples of a conveyance section 16 that conveys the print medium 30. The number of rollers provided in the middle of the conveyance path for conveying the print medium 30, the arrangement, and the like are not limited to those shown in the drawing. Further, the color of the ink ejected from the print head 18 is not limited to the colors described above. Needless to say, a flat platen or the like that supports the print medium 30 from below to receive the ink ejected from the print head 18 can be provided between the front drive roller 23 and the rear drive roller 24. Further, the portion of the print medium 30 on which printing based on the print head 18 is performed can not be wound into a roll shape by the winding shaft 25, but can be cut and separated from the print medium 30 upstream of the portion by a cutter not shown and recovered. Figure 2 In the example shown in the drawing, the read section 19 is provided at a position more downstream than the carriage 17 and the print head 18 and more upstream than the rear drive roller 24. The read section 19 optically reads the print medium 30 on which printing has been performed by the print head 18 by an image sensor, and outputs image data as a result of the reading. The read section 19 can be configured to read the print medium 30 while moving by the carriage, like the print head 18, or can be configured to read in a stationary state.

[0036] Figure 2 The relationship of the print medium 30 and the print head 18 is simply shown from a viewpoint of looking from above. The print head 18 mounted on the carriage 17 moves together with the carriage 17 from one end toward the other end of the main scanning direction Dl (forward movement), and from the other end toward the one end (return movement). The main scanning direction Dl intersects the conveyance direction D2. The intersection can also be understood as being orthogonal. Therefore,

[0037] Figure 3 Figure 2 ​​The print head 18 and the like are shown based on a viewpoint toward the main scanning direction Dl. However, due to various errors in, for example, a printer as a product, there are cases where the main scanning direction Dl and the conveyance direction D2 are not strictly orthogonal.

[0038] In Figure 3 , an example of arrangement of the nozzles 21 on the nozzle face 20 is shown. One by one small circles in the nozzle face 20 are the nozzles 21. The print head 18 has a plurality of nozzle rows 26 in a configuration that receives supply of various color inks from a not-shown liquid holding unit called an ink cartridge, an ink tank, or the like and ejects the inks from the nozzles 21. Figure 3 is an example of the print head 18 that ejects CMYK inks. A nozzle row 26 constituted by the nozzles 21 that eject C ink is also referred to as nozzle row 26C. Similarly, a nozzle row 26 constituted by the nozzles 21 that eject M ink is sometimes referred to as nozzle row 26M, a nozzle row 26 constituted by the nozzles 21 that eject Y ink is sometimes referred to as nozzle row 26Y, and a nozzle row 26 constituted by the nozzles 21 that eject K ink is sometimes referred to as nozzle row 26K. The nozzle rows 26C, 26M, 26Y, 26K are arranged along the main scanning direction Dl.

[0039] Each nozzle row 26 is constituted by a plurality of nozzles 21 whose intervals between the nozzles 21 in the conveyance direction D2, that is, nozzle pitches, are constant or substantially constant. A direction in which the plurality of nozzles 21 constituting the nozzle row 26 are arranged is referred to as nozzle row direction D3. In Figure 3 , the nozzle row direction D3 is parallel to the conveyance direction D2. In the configuration where the nozzle row direction D3 is parallel to the conveyance direction D2, the nozzle row direction D3 is orthogonal to the main scanning direction Dl. However, the configuration where the nozzle row direction D3 is not parallel to the conveyance direction D2 but crosses the main scanning direction Dl obliquely is also possible.

[0040] Each of the plurality of nozzles 21 can eject a plurality of sizes of dots whose volumes per one drop are different. In the present embodiment, when a dot of a certain size is referred to as a "first size" dot, a dot of a size smaller than the first size is referred to as a "second size" dot. Hereinafter, for convenience, the first size dot is referred to as a "large dot" and the second size dot is referred to as a "small dot". The respective sizes of the large dot and the small dot are sizes determined by design.

[0041] The positions of the nozzle rows 26C, 26M, 26Y, 26K in the conveyance direction D2 are identical to each other. The printing device 10 prints an image on the printing medium 30 by combining the conveyance of the printing medium 30 toward the conveyance direction D2 and the ink ejection of the printhead 18 along with the movement of the carriage 17 in the main scanning direction Dl. The action of the printhead 18 to perform the ink ejection along with the forward movement and the return movement of the carriage 17 is called "scanning" or "pass". The movement of the printhead 18 in the main scanning direction Dl by the carriage 17 corresponds to a kind of relative movement of the printhead 18 to the printing medium 30.

[0042] 2. Test pattern printing:

[0043] Figure 4 The flow from the printing of the TP to the inspection based on the TP of the nozzle 21 performed by the control section 11 according to the program 12 is shown by a flowchart. TP is an abbreviation of test pattern. The flowchart is roughly composed of a TP printing process (step S100), an acquisition of a reading result of the printed TP (step S200), and an inspection based on the reading result of the TP (step S300). The step S100 corresponds to a printing process of the TP. In Figure 4 The step S100 is subdivided into steps S110 to S150 in the flowchart.

[0044] In the step S110, the printing control section 12a acquires TP image data which is image data representing a TP from a prescribed storage, a storage device, or the like which the control section 11 can communicate with. The TP image data is, for example, image data in a bitmap form in which the color of each pixel is prescribed in a prescribed color specification system. The color specification system described herein refers to various color specification systems such as an RGB (red, green, blue) color specification system, a CMYK color specification system, and the like.

[0045] In the step S120, the printing control section 12a sets a printing condition of the TP. The printing control section 12a directly sets the printing condition at the time of ordinary printing as the printing condition of the TP. The ordinary printing refers to a process of printing an object such as a photo, a text, a CG, or the like arbitrarily selected by a user, rather than printing the TP. The printing condition for the ordinary printing can be set by the user visually confirming a user interface (UI) screen displayed on the display section 13 while operating the operation receiving section 14. The printing condition includes, for example, the kind of the printing medium 30, the printing quality.

[0046] The print quality is prompted to the user by, for example, a sensory option of high quality, normal quality, fast, but the print control section 12a sets the moving speed of the carriage 17, the conveyance speed of the conveyance section 16, the waveform of the drive signal for driving the nozzle 21, the drive cycle of the nozzle 21 in the stroke, and the like, which are required for the print execution, in accordance with the selection of the print quality. Further, there are prepared initial settings in the print condition, and when the user does not particularly change the initial settings, the print control section 12a applies such initial settings to the print of the TP, the normal print.

[0047] The execution order of the step S110 and the step S120 can also be reversed from the order of the description in Figure 4 , and can also be performed substantially simultaneously.

[0048] In the step S130, the print control section 12a generates print data for printing the TP from the TP image data. The print control section 12a performs a prescribed image processing such as a color conversion processing, a halftone processing, as required, on the TP image data, thereby generating print data in which the ink ejection (Dot On) or the ink non-ejection (Dot Off) is prescribed for each pixel and for each ink color. The Dot On here means either of the presence of a large dot or the presence of a small dot. As shown in the example of Figure 3 , when it is assumed that the ink of four colors of CMYK is used by the print head 18, in the step S130, the print control section 12a generates print data in which the Dot On / Dot Off is prescribed for each pixel and for each of CMYK, based on the TP image data.

[0049] Figure 5 An example of the TP image data 40 acquired in the step S110 is shown. The TP image data 40 is image data that represents the TP 41. In Figure 5 and the later-described Figure 6 , the correspondence of the TP image data 40 to the directions Dl, D2 is also shown. The TP 41 includes the TP of each ink color. According to Figure 5 , the TPs 41CL, 41CS are TPs that represent the color by C. Similarly, the TPs 41ML, 41MS are TPs of M color, the TPs 41YL, 41YS are TPs of Y color, and the TPs 41KL, 41KS are TPs of K color. Further, the TPs 41CL, 41ML, 41YL, 41KL are TPs that are printed by a large dot in the corresponding color, respectively, and the TPs 41CS, 41MS, 41YS, 41KS are TPs that are printed by a small dot in the corresponding color, respectively.

[0050] In the TP image data 40, the TPs 41CL, 41CS, 41ML, 41MS, 41YL, 41YS, 41KL, 41KS by ink color and by size are arranged in correspondence in the main scanning direction Dl, and the positions in the conveyance direction D2 are the same as each other. The TPs 41CL, 41CS, 41ML, 41MS, 41YL, 41YS, 41KL, 41KS are each a collection of a plurality of "pattern elements". In Figure 5 In the example, one pattern element is a grid line parallel to the main scanning direction Dl. One pattern element is an image printed by one nozzle 21 of the corresponding ink color.

[0051] Figure 6 A portion of the TPs 41 represented by the TP image data 40 is shown enlarged. Specifically, a portion of each of the TPs 41CL, 41CS is shown in Figure 6 The TP 41CL is composed of a plurality of pattern elements 42CL arranged at equal intervals in the conveyance direction D2, and the TP 41CS is composed of a plurality of pattern elements 42CS arranged at equal intervals in the conveyance direction D2. In Figure 6 In order to facilitate understanding, a portion of the nozzle row 26C used for printing of these TPs 41CL, 41CS is shown together with the TPs 41CL, 41CS in That is, each pattern element 42CL is arranged at an interval equal to the nozzle pitch in the conveyance direction D2 so that one pattern element 42CL constituting the TP 41CL is printed by one nozzle 21 constituting the nozzle row 26C. Similarly, each pattern element 42CS is arranged at an interval equal to the nozzle pitch in the conveyance direction D2 so that one pattern element 42CS constituting the TP 41CS is printed by one nozzle 21 constituting the nozzle row 26C.

[0052] Figure 6 In addition, in the example, in order to facilitate confirmation of each of the pattern elements 42CL at the time of inspection, the pattern elements 42CL are arranged at staggered positions in the main scanning direction Dl so that the positions in the main scanning direction Dl are consistent in a cycle of three. Similarly, the pattern elements 42CS are also arranged at staggered positions in the main scanning direction Dl so that the positions of the pattern elements 42CS in the main scanning direction Dl are consistent in a cycle of three. However, the positions of the pattern elements constituting the TPs corresponding to one combination of ink color and dot size in the main scanning direction Dl can also be all the same.

[0053] In addition, in the example, in order to facilitate confirmation of each of the pattern elements 42CL at the time of inspection, the pattern elements 42CL are arranged at staggered positions in the main scanning direction Dl so that the positions in the main scanning direction Dl are consistent in a cycle of three. Similarly, the pattern elements 42CS are also arranged at staggered positions in the main scanning direction Dl so that the positions of the pattern elements 42CS in the main scanning direction Dl are consistent in a cycle of three. However, the positions of the pattern elements constituting the TPs corresponding to one combination of ink color and dot size in the main scanning direction Dl can also be all the same. Figure 6In the example of FIG. 6, in order to reduce the bleeding of one of the pattern elements 42CL and 42CS, the pattern elements 42CL and 42CS are arranged at positions that are offset by one dot in the main scanning direction Dl. For example, in the case where the pattern element 42CL is printed by two passes, the dots printed by the first pass are arranged at odd-numbered pixel positions in the main scanning direction Dl, and the dots printed by the second pass are arranged at even-numbered pixel positions in the main scanning direction Dl. Also, for example, in the case where the pattern element 42CS is printed by six passes, the dots printed by the first, third, and fifth passes are arranged at odd-numbered pixel positions in the main scanning direction Dl, and the dots printed by the second, fourth, and sixth passes are arranged at even-numbered pixel positions in the main scanning direction Dl. However, in the case of printing a print medium in which bleeding is less likely to occur, dots can be formed by each pass at all pixels.

[0054] The print data generated in step S130 is image data in which the TP 41 representing such TP image data 40 is expressed in dots / no dots. Each pattern element that respectively constitutes the TPs 41CL, 41CS, 41ML, 41MS, 41YL, 41YS, 41KL, 41KS is formed only by dots of the corresponding ink color and size.

[0055] In step S140, the print control section 12a determines the number of passes and the removal rate at the time of printing the TP for each dot size. As shown in FIG. 6, since the TP 41 is constituted by the TPs 41CL, 41CS, 41ML, 41MS, 41YL, 41YS, 41KL, 41KS, the print control section 12a determines the number of passes and the removal rate for each of the TPs 41CL, 41CS, 41ML, 41MS, 41YL, 41YS, 41KL, 41KS according to the dot size. Figure 5

[0056] In the present embodiment, a pattern element formed by a plurality of dots of a first size is referred to as a "first pattern element", and a pattern element formed by a plurality of dots of a second size is referred to as a "second pattern element". Each pattern element constituting the TP 41 is classified as either a first pattern element or a second pattern element according to the size of the dots. Figure 6 Each pattern element 42CL of the TP 41CL shown in FIG. 6 is an example of a first pattern element, and each pattern element 42CS constituting the TP 41CS is an example of a second pattern element.

[0057] Figure 7 An example of a different-size dot number table 50 is shown in FIG. 7. The different-size dot number table 50 is stored in advance in a memory or storage device inside or outside the printing device 10 that is accessible by the control section 11. The different-size dot number table 50 is a table that defines parameters that directly or indirectly determine the number of dots used to print the TP of each dot size on the print medium 30. According to the different-size dot number table 50, the number of dots used to print the TP of each dot size is determined according to the dot size.​Figure 7 The different-size dot number table 50 defines the number of strokes and the removal rate for each of the large dots and the small dots as the dot size. In step S140, the print control section 12a determines the number of strokes and the removal rate for each dot size with reference to the different-size dot number table 50.

[0058] The number of strokes is the number of strokes of the TP. For example, with respect to a certain dot size, if the number of strokes = 2, the TP of one color of the dot size represented by the print data generated in step S130 is not shared by two strokes, but the stroke of the TP of one color of the dot size represented by the print data is repeated twice. Therefore, the more the number of strokes, the more the number of dots of the TP reproduced on the print medium 30 increases. According to the different-size dot number table 50, the print control section 12a determines the number of strokes = 2 with respect to the large dots and the number of strokes = 6 with respect to the small dots.

[0059] The removal rate is the removal rate in one stroke. For example, with respect to a certain dot size, if the removal rate = 50%, in one stroke, with respect to 50% of the pixels, regardless of whether the pixel is a dot or not, the pixel is forcibly made a non-dot without ejecting ink, during the period of the TP of one ink color of the dot size represented by the print data generated in the print step S130. Therefore, the higher the removal rate, the more the number of dots of the TP reproduced on the print medium 30 decreases. In addition, it can be said that if the removal rate is high, the ejection rate of the ink from the nozzle 21 decreases, and if the removal rate is low, the ejection rate of the ink from the nozzle 21 increases. Therefore, by changing the removal rate for each dot size, it is possible to control the ejection rate of the nozzle 21 for each dot size. According to the different-size dot number table 50, the print control section 12a determines the removal rate = 50% with respect to the large dots and the removal rate = 0% with respect to the small dots. The removal rate = 0% means that the print is performed according to the print data for each stroke.

[0060] Here, it is assumed that each pattern element constituting any one of the TPs 41CL, 41CS, 41ML, 41MS, 41YL, 41YS, 41KL, 41KS is constituted by substantially the same number of dots in the print data generated in step S130. According to the step ST140 of referring to the different size dot table 50, it is determined that the number of passes = 2 and the removal rate = 50% for the TPs 41CL, 41ML, 41YL, 41KL which are TPs based on large dots, and the number of passes = 6 and the removal rate = 0% for the TPs 41CS, 41MS, 41YS, 41KS which are TPs based on small dots. Therefore, when comparing the number of dots between the pattern elements printed on the print medium 30 in reflection of the determination of step S140, the number of dots of one second pattern element, for example, the small dots of C ink forming one pattern element 42CS, becomes approximately six times the number of dots of one first pattern element, for example, the large dots of C ink forming one pattern element 42CL.

[0061] In step S150, the print control section 12a controls the movement of the carriage 17 and the ejection of ink from the print head 18 in accordance with the print conditions set in step S120, the print data generated in step S130, the number of passes and the removal rate of each dot size determined in step S140, thereby causing the TP 41 to be printed on the print medium 30. Specifically, the print head 18 performs six passes to print the TP 41 on the print medium 30 in accordance with the different size dot table 50. The print head 18 ejects small dots of CMYK ink from each nozzle 21 of the nozzle rows 26C, 26M, 26Y, 26K respectively by all six of the six passes, and prints the TPs 41CS, 41MS, 41YS, 41KS based on the print data and with a removal rate of 0%. In addition, the print head 18 ejects large dots of CMYK ink from each nozzle 21 of the nozzle rows 26C, 26M, 26Y, 26K respectively by two of the six passes, and prints the TPs 41CL, 41ML, 41YL, 41KL based on the print data and with a removal rate of 50%.

[0062] As a result, the print control section 12a prints the TP 41 in which the number of dots of the second size forming the second pattern element is more than the number of dots of the first size forming the first pattern element when compared in pattern element units. Note that the print control section 12a does not cause the conveyance section 16 to convey the print medium 30 during the period from the start of the first pass to the end of the last pass for printing the TP 41 by the print head 18 in step S150.

[0063] The above is a description of step S100. Step S200, S300 will be described briefly.

[0064] In step S200, the reading control section 12b acquires image data as a reading result from the reading section 19 by controlling the reading section 19 to perform reading of the print medium 30 after the TP 41 is printed in step S100. Of course, the conveyance section 16 performs conveyance of an amount necessary for the reading section 19 to read the printed print medium 30.

[0065] However, in step S200, it is only necessary to acquire a reading result of the print medium 30 on which the TP 41 is printed. Therefore, it is also possible that the user causes an external scanner to read the print medium 30 on which the TP 41 is printed, and the printing device 10 acquires the reading result through the communication IF 15.

[0066] In step S300, the checking section 12c checks the state of ink ejection of the nozzles 21 of the print head 18 based on the image data acquired as a reading result in step S200. The state of ink ejection is classified into normal and abnormal. The abnormal is non-ejection of a point that cannot eject a point, landing position deviation of a point that deviates from an ideal position, and the like. The checking section 12c checks whether each nozzle 21 normally or abnormally ejects ink of each dot size by analyzing the image data and specifying the density and position of each pattern element, and saves the checking result as data.

[0067] The above, Figure 4 The flowchart ends.

[0068] 3. Summary and explanation of effects:

[0069] Thus, according to the present embodiment, the printing device 10 includes the print head 18 having the nozzles 21 that eject a dot of a first size and a dot of a second size smaller than the first size as ink, and the control section 11 that causes the print head 18 to print a TP for checking the state of ink ejection of the nozzles 21 to the print medium 30 by controlling the print head 18. The TP has a first pattern element formed of a plurality of dots of the first size and a second pattern element formed of a plurality of dots of the second size. Further, the control section 11 causes the print head 18 to print the TP in which the number of dots of the second size forming the second pattern element is more than the number of dots of the first size forming the first pattern element.

[0070] According to the configuration, the first pattern element of a larger dot than the dot of the first size is printed using more dots, and the second pattern element of a smaller dot of the second size is printed. As a result, the second pattern element can be printed more densely to some extent. Thus, it is possible to eliminate the problem that, due to a small difference in brightness from the print medium 30, for the portion on which a dot of a smaller size is printed for checking the TP of each nozzle 21, reading is not properly performed, and checking based on the reading result is not properly performed. Specifically, regarding the pattern element having a small difference in brightness from the print medium 30 of white or bright color, when checking based on the reading result is performed, since it is difficult to accurately specify the position and the like, it is not possible to accurately determine whether the pattern element is normal or abnormal, but if the TP printed in step S100 of the present embodiment is used, it is possible to accurately check the nozzles 21 that eject dots of different sizes, respectively, according to the pattern element.

[0071] Further, according to the present embodiment, the print head 18 can perform scanning in which ink is ejected from the nozzles 21 along with movement in a predetermined direction, and the control section 11 causes the print head 18 to print the TP by causing the print head 18 to print the second pattern element more times than the first pattern element. That is, the control section 11 causes the print head 18 to print the TP in such a manner that the number of times of scanning for printing the second pattern element is larger than the number of times of scanning for printing the first pattern element.

[0072] According to the configuration, the control section 11 can easily print the TP in which the number of dots of the second size forming the second pattern element is larger than the number of dots of the first size forming the first pattern element, by causing the number of times of scanning for printing the second pattern element to be larger than the number of times of scanning for printing the first pattern element.

[0073] Further, according to the present embodiment, it can also be that the control section 11 causes the print head 18 to print the TP by causing the nozzles 21 to eject dots of the second size for printing the second pattern element at a higher rate than the nozzles 21 eject dots of the first size for printing the first pattern element. That is, the control section 11 causes the print head 18 to print the TP in such a manner that the rate at which the nozzles 21 eject dots of the second size for printing the second pattern element is higher than the rate at which the nozzles 21 eject dots of the first size for printing the first pattern element.

[0074] According to the configuration, the control section 11 can easily print the TP in which the number of dots of the second size forming the second pattern element is larger than the number of dots of the first size forming the first pattern element, by causing the nozzles 21 to eject dots of the second size for printing the second pattern element at a higher rate than the nozzles 21 eject dots of the first size for printing the first pattern element.

[0075] Figure 7The values of the number of strokes and the removal rate for each dot size in the different-size dot table 50 shown are merely an example. In addition, the different-size dot table 50 can be, for example, a table in which the number of strokes is set to be the same regardless of the dot size and the removal rate is set to be different between the first size and the second size. Alternatively, the different-size dot table 50 can be a table in which the removal rate is set to be the same regardless of the dot size and the number of strokes is set to be different between the first size and the second size.

[0076] Further, according to the present embodiment, the printing condition at the time of printing the TP is the same as the printing condition at the time of performing the ordinary printing.

[0077] That is, the control section 11 makes the speed of the relative movement at the time of printing the TP by the relative movement of the printhead 18 and the print medium 30 the same as the speed of the relative movement at the time of performing the ordinary printing. According to the previous description, the speed of the relative movement here is the speed of the movement of the carriage 17 at the time of stroke execution.

[0078] Further, the control section 11 makes the waveform of the drive signal for driving the nozzle 21 at the time of printing the TP the same as the waveform of the drive signal for driving the nozzle 21 at the time of performing the ordinary printing. The drive signal for driving the nozzle 21 is a pulse wave, and by applying this drive signal to the unit drive element of the nozzle 21 according to the information of the dot, the dot is ejected from the nozzle 21. If the waveforms of the drive signals are different, the size of the dot ejected by one drive of the nozzle 21 is also different. Therefore, in the present embodiment, the waveform of the drive signal for ejecting the first dot from the nozzle 21 at the time of printing the TP is made the same as the waveform of the drive signal for ejecting the first dot from the nozzle 21 at the time of performing the ordinary printing, and likewise, the waveform of the drive signal for ejecting the second dot from the nozzle 21 at the time of printing the TP is made the same as the waveform of the drive signal for ejecting the second dot from the nozzle 21 at the time of performing the ordinary printing.

[0079] In this way, by sharing the speed of the relative movement, the drive signal in the printing of the TP and the ordinary printing, it is possible to print the TP suitable for performing the inspection of the nozzle 21 in the same condition as at the time of performing the ordinary printing.

[0080] The present embodiment also discloses various kinds of inventions such as the method other than the printing device 10, the printing system 10, and the program 12.

[0081] The printing method has a printing step of printing the TP to a print medium using a print head 18 having nozzles 21 that eject dots of a first size that are dots of ink and dots of a second size that are smaller than the first size, the TP being for checking a state of ejection of ink by the nozzles 21, the TP having first pattern elements formed of a plurality of dots of the first size and second pattern elements formed of a plurality of dots of the second size, in the printing step, the print head 18 is caused to print the TP in which the number of dots of the second size forming the second pattern elements is more than the number of dots of the first size forming the first pattern elements.

[0082] 4. Other Embodiments

[0083] The present embodiment is not limited to the above aspect.

[0084] The plurality of nozzles 21 of the print head 18 can each eject more than two kinds of dot sizes. The nozzles 21 may, for example, eject large dots, medium dots, and small dots in order from the largest volume per drop. In this case, in the present embodiment, the large dots can be treated as the first size, and the medium dots and the small dots can be treated as the second size, or the large dots and the medium dots can be treated as the first size, and the small dots can be treated as the second size.

[0085] In addition, it can also be that the printing device 10 prints the TP in such a manner that the smaller the dot size, the more the number of dots per pattern element, for the pattern elements based on the large dots, the pattern elements based on the medium dots, and the pattern elements based on the small dots, respectively.

[0086] In addition, it can also be that the "large dots" that are dots of the first size are formed by ejecting a plurality of "small dots" that are dots of the second size.

[0087] In addition, in the present embodiment, the dots of the first size and the dots of the second size are ejected from the same nozzle, but this is not limiting, and the print head 18 can also have a nozzle for ejection of the first size and a nozzle for ejection of the second size, respectively.

[0088] The printing device 10 can also be a so-called serial type inkjet printer in which the print head 18 is mounted to the carriage 17 that moves in the main scanning direction D1, as previously described.

[0089] It can also be assumed that the printing device 10 is a so-called line type inkjet printer in which ink ejection is performed by the print head 18 having nozzle rows 26 that extend in the main scanning direction D1 that intersects the conveyance direction D2, and that have a length capable of covering the width of the print medium 30, corresponding to each ink color. In the line type inkjet printer, the nozzle row direction D3 can be understood as being parallel to the main scanning direction D1 and not the conveyance direction D2.

[0090] When the present embodiment is described assuming that the printing device 10 is a line type inkjet printer,Figure 5 The TP 41 shown is printed on the print medium 30 in the direction parallel to the conveyance direction D2, not in the main scanning direction Dl, as each pattern element of the grid line. Further, as to the stroke of the print head 18 explained before, the implementation is made by the reverse feed of the conveyance section 16 in correspondence. The reverse feed is a process in which the conveyance section 16 conveys the print medium 30 from the downstream to the upstream. That is, when the print medium 30 passes under the print head 18 in the course of conveying the print medium 30 from the upstream to the downstream, the printing on the print medium 30 is made once. Thereafter, the conveyance section 16 performs the reverse feed to return the portion of the print medium 30 on which the printing is finished to a position more upstream than the print head 18 and starts the conveyance from there to the downstream. By repeating this process, the TP 41 can be printed repeatedly as with the serial inkjet printer which prints the TP 41 by the multiple strokes.

[0091] When the printing apparatus 10 is the line inkjet printer, the conveyance of the print medium 30 by the conveyance section 16 in the printing period of the print head 18 corresponds to the relative movement of the print head 18 and the print medium 30. That is, when the printing apparatus 10 is the line inkjet printer, the conveyance speed of the conveyance section 16 in the printing period of the print head 18 is common to the printing of the TP and the ordinary printing.

[0092] Needless to say, the print medium 30 can not be Figure 2 The print medium 30 shown is a continuous paper wound in a roll shape or the like. The print medium 30 can be a single sheet paper or the like which is separated in units of pages.

Claims

1. A printing apparatus, characterized in that, It is equipped with a print head and a control unit. The print head has nozzles that eject dots of a first size as ink points and dots of a second size smaller than the first size. The control unit controls the print head to print a test pattern on the printing medium, used to check the state of ink ejection from the nozzles. The test pattern has a first pattern element formed by a plurality of points of the first size and a second pattern element formed by a plurality of points of the second size. The control unit causes the print head to print the test pattern, in which the number of dots forming the second size of the second pattern element is greater than the number of dots forming the first size of the first pattern element. The print head is capable of performing a scan by ejecting ink from the nozzle as it moves in a predetermined direction. The control unit causes the print head to print the test pattern in such a way that the number of scans for printing the second pattern element is greater than the number of scans for printing the first pattern element.

2. The printing apparatus according to claim 1, characterized in that, The control unit causes the print head to print the test pattern in such a manner that the nozzle ejects dots of the second size for printing the second pattern element at a higher ejection rate than the nozzle ejects dots of the first size for printing the first pattern element.

3. The printing apparatus according to claim 1, characterized in that, The control unit ensures that the speed of the relative movement when printing the test pattern via the relative movement of the print head and the printing medium is the same as the speed of the relative movement during ordinary printing.

4. The printing apparatus according to claim 1, characterized in that, The control unit makes the waveform of the drive signal used to drive the nozzle when printing the test pattern the same as the waveform of the drive signal used to drive the nozzle when performing normal printing.

5. A printing method, characterized in that, It has a printing process. In the printing process, a test pattern is printed onto the printing medium using a print head. The print head has nozzles that eject dots of a first size as ink points and dots of a second size smaller than the first size. The test pattern is used to check the state of ink ejection from the nozzles. The test pattern has a first pattern element formed by a plurality of points of the first size and a second pattern element formed by a plurality of points of the second size. In the printing process, the print head prints the test pattern, wherein the number of dots forming the second size of the second pattern element in the test pattern is greater than the number of dots forming the first size of the first pattern element. The print head is capable of performing a scan by ejecting ink from the nozzle as it moves in a predetermined direction. In the printing process, the print head prints the test pattern in such a way that the number of scans for printing the second pattern element is greater than the number of scans for printing the first pattern element.

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