Printing apparatus and control method thereof

Abstract

The invention provides a printing apparatus and a control method thereof. One aspect of the present invention is the printing apparatus comprising: a printhead comprising a first nozzle array and a second nozzle array; and a printing control means for performing printing by driving the print head while reciprocating the print head as a serial head, in which the first nozzle array discharges the color ink and the second nozzle array discharges the reaction liquid, and for each of the forward path and the reverse path, the second nozzle array discharges the reaction liquid. An adjustment pattern is formed by overlapping the pattern of the reaction liquid with the pattern of the color ink, and in a case where the adjustment pattern is formed in the reverse path, an underlayer pattern is further formed through the second nozzle array in a previous forward path.

Description

Technical Field

[0001] The present invention mainly relates to an inkjet printing device. Background Art

[0002] Some inkjet printing devices eject color ink and additionally eject a reaction liquid that reacts with the color ink ejected onto a print medium (see Japanese Unexamined Patent Application Publication No. 2001-138494). When the reaction liquid reacts with the color ink, the color ink can be fixed on the print medium. The ejection positions of the color ink and the reaction liquid need to be substantially consistent with each other on the print medium. Since the reaction liquid is usually colorless and transparent, a technique for appropriately adjusting the ejection position of the reaction liquid is generally required.

[0003] In the case of a so-called serial head (the serial head is a print head configured to perform printing while reciprocating on a print medium), between the forward path and the reverse path of the print head, the ejection position of the reaction liquid may vary. In addition, which of the color ink and the reaction liquid is ejected onto the print medium first also varies between the forward path and the reverse path. Therefore, a technique that can relatively easily achieve appropriate adjustment of the ejection position of the reaction liquid is required. Summary of the Invention

[0004] The present invention relatively easily achieves adjustment of the ejection position of a reaction liquid in an inkjet printing device including a serial head.

[0005] One aspect of the present invention provides a printing device, characterized by including: a print head including a first nozzle array and a second nozzle array; and a print control component for driving the print head to perform printing on a print medium while reciprocating the print head as a serial head, wherein the first nozzle array is configured to eject color ink, the second nozzle array is configured to eject a reaction liquid that reacts with the color ink and fixes the color ink on the print medium, and in a case where the moving direction of the print head with the second nozzle array located on the downstream side relative to the first nozzle array is defined as a forward path and the opposite direction is defined as a reverse path, the print control component executes first drive control for driving the print head such that: for each of the forward path and the reverse path of the print head, an adjustment pattern is formed, the adjustment pattern is configured to adjust the ejection position, and the adjustment pattern is formed by overlapping the pattern of the reaction liquid and the pattern of the color ink, and in a case where the adjustment pattern is formed in the reverse path of the print head, in a previous forward path, a bottom layer pattern is further formed through the second nozzle array.

[0006] Another aspect of the present invention provides a control method for a printing device, the printing device including: a print head including a first nozzle array and a second nozzle array; and a print control component configured to perform printing on a print medium by driving the print head while reciprocating the print head as a serial head. The method is characterized in that the first nozzle array is configured to discharge color ink, the second nozzle array is configured to discharge a reaction liquid that reacts with the color ink and fixes the color ink on the print medium, and in a case where a moving direction of the print head with the second nozzle array located on a downstream side relative to the first nozzle array is defined as a forward path and an opposite direction is defined as a reverse path, the control method includes: for each of the forward path and the reverse path of the print head, forming an adjustment pattern configured to adjust a discharge position, and the adjustment pattern is formed by overlapping a pattern of the reaction liquid and a pattern of the color ink; and in a case where the adjustment pattern is formed in the reverse path of the print head, in a previous forward path, further forming an underlayer pattern through the second nozzle array.

[0007] Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is an overall perspective view of a printing device according to an embodiment;

[0009] Figure 2 is a schematic cross-sectional view showing an internal configuration of the printing device;

[0010] Figure 3A and Figure 3B is a schematic view showing an example of a configuration of an optical sensor;

[0011] Figure 4 is a schematic view showing a nozzle outlet surface of the print head;

[0012] Figure 5 is a block diagram for explaining a control system of the printing device;

[0013] Figure 6A 、 Figure 6B and Figure 6C are schematic views showing examples of sub-patterns each forming an adjustment pattern;

[0014] Figure 7A 、 Figure 7B 、 Figure 7C and Figure 7D are schematic views showing examples of dot densities of the sub-patterns;

[0015] Figure 8It is a schematic diagram showing an example of the detection result of an optical sensor;

[0016] Figure 9 It is a schematic diagram showing an example of the detection result of an optical sensor;

[0017] Figure 10 It is a schematic diagram showing an example of an adjustment pattern for the forward path;

[0018] Figure 11 It is a schematic diagram showing an example of an adjustment pattern for the reverse path;

[0019] Figure 12A and Figure 12B It is a schematic diagram showing a reference example of a method for printing an adjustment pattern;

[0020] Figure 13A and Figure 13B It is a schematic diagram showing an outline of a first example of a method for printing an adjustment pattern;

[0021] Figure 14 It is a schematic diagram showing details of a first example of a method for printing an adjustment pattern;

[0022] Figure 15A and Figure 15B It is a schematic diagram showing an outline of a second example of a method for printing an adjustment pattern;

[0023] Figure 16 It is a schematic diagram showing details of a second example of a method for printing an adjustment pattern;

[0024] Figure 17 It is a schematic diagram showing details of a third example of a method for printing an adjustment pattern;

[0025] Figure 18 It is a flowchart showing a method for correcting the position offset of the reaction solution;

[0026] Figure 19 It is a schematic diagram showing an example of an adjustment pattern for evaluating the position offset of the reaction solution;

[0027] Figure 20 It is a flowchart showing a method for correcting the position offset of the reaction solution; and

[0028] Figure 21 It is a flowchart showing a method for correcting the position offset of the reaction solution. Detailed Description

[0029] In the following, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention. In the embodiments, a plurality of features are described, but the invention is not limited to the invention that requires all such features, and a plurality of such features can be appropriately combined. In addition, in the drawings, the same reference numerals are given to the same or similar configurations, and redundant descriptions thereof are omitted.

[0030] <Configuration of the printing device>

[0031] Figure 1 is an overall perspective view showing an example of a printing device 10 according to an embodiment. Figure 2 is a schematic cross-sectional view showing the internal configuration of the printing device 10.

[0032] The printing device 10 is a so-called serial scanning type, which transports a printing medium P in the device main body and performs printing while reciprocating / moving the print head 24 in a direction crossing the transport direction. The print head 24 is represented as a serial head. Printing is performed by an inkjet method, and printing is performed by discharging ink onto the printing medium P and forming an image. Note that the concept of an image includes not only characters, numbers, symbols, graphics, and photos, but also blanks formed between them.

[0033] In Figure 1 and Figure 2 and other drawings to be described later, the width direction of the printing device 10 is the X direction, the depth direction is the Y direction, and the height direction is the Z direction. The X direction corresponds to the scanning direction of the print head 24, and the Y direction corresponds to the transport direction of the printing medium P. In the following description, “+” or “-” is added to distinguish one direction and the other direction in each of the X to Z directions. For example, one direction (the downstream side direction) in the X direction is represented as the “+X direction”, and the other direction (the upstream side direction) in the X direction is represented as the “-X direction”.

[0034] The printing device 10 includes a platen 12 for supporting the printing medium P transported in the device main body and a printing unit 14 for printing on the printing medium P supported by the platen 12. In addition, the printing device 10 includes a heating unit 16 for heating the printing surface Pf of the printing medium P (hereinafter sometimes simply referred to as “printed product”) that has been printed by the printing unit 14.

[0035] A transport unit or mechanism for transporting the print medium P sequentially withdraws / unwinds the print medium P from a sheet roll 27 formed by winding the sheet-like print medium P through transport rollers 23 driven, for example, via gears by a transport motor (not shown), and feeds the print medium P. The fed print medium P is transported to the platen 12 and printed by the print unit 14. The printed print medium P is wound again by the reel 21. Note that the transport unit is not limited to this example, and other known configurations may be employed.

[0036] The print unit 14 includes a print head 24, and also includes a guide shaft 20 and a carriage 22 which is attached to be movable along the guide shaft 20. The guide shaft 20 extends in the X direction, and thus the carriage 22 can reciprocate in the X direction. The print head 24 includes a plurality of ejection ports (nozzles) 32 (to be described later) configured to eject ink (see Figure 4 ), and the print head 24 is detachably attached to the carriage 22 such that an ejection port surface (nozzle surface) 34 (see Figure 2 ) on which the plurality of ejection ports 32 are arranged faces the platen 12.

[0037] With this configuration, the print head 24 performs printing by ejecting ink onto the print medium P while reciprocating in the X direction.

[0038] Note that the movement mechanism of the carriage 22 only needs to use a known configuration, and may be formed, for example, by a carriage motor and a carriage belt or a lead screw for transmitting the driving force from the carriage motor.

[0039] The printing apparatus 10 further includes an optical encoder 30 extending in the X direction, and the position of the print head 24 can be controlled by the control unit 100 (see Figure 5 ) based on the signal of the encoder 30.

[0040] The print head 24 can eject ink containing a coloring agent and a reaction liquid that reacts with the ink to change the viscosity of the ink, thereby thickening or solidifying the ink. The ink containing the coloring agent is color ink, and typical examples are black ink (K ink), cyan ink (C ink), magenta ink (M ink), and yellow ink (Y ink). These four color inks are pigment inks containing coloring agents for presenting the corresponding colors.

[0041] Hereinafter, the colors of the color inks may be simply represented as K, C, M, and Y, but the colors and the number of the color inks are not limited to the above four colors. In addition, in this specification, the color inks may be simply represented as ink, and the ink and the reaction liquid may be collectively represented as liquid.

[0042] In this embodiment, the printing unit 14 including the print head 24 can reciprocate at a speed of 45 inches per second and perform printing at a resolution of 1200 dpi (dots per inch), that is, at an interval of 1 / 1200 inch. When starting to print, the control unit 100 moves the print head 24 to the print start position and causes the above-described conveying unit to convey the print medium P to a position where the print head 24 can print. Thereafter, based on the print data, the control unit 100 alternately performs a scanning print operation of printing while moving the print head 24 in the X direction and a conveying operation of causing the conveying unit to convey the print medium P by a predetermined amount according to the completion of the scanning print operation. By repeating the scanning print operation and the conveying operation, printing on the print medium P is achieved.

[0043] The area corresponding to one scanning operation of the print head 24 can be represented as a unit area. In this embodiment, printing for the unit area is achieved by so-called multipass printing. That is, the print head 24 scans the unit area of the print medium P whose conveyance is stopped multiple times. For example, in order to achieve printing for the unit area by two scanning operations, the print head 24 performs a part of the printing for the unit area in the forward path (for example, scanning in the -X direction) and the remaining part of the printing for the unit area in the reverse path (for example, scanning in the +X direction).

[0044] The heating unit 16 applies heat to the printed surface Pf of the printed print medium P, thereby fixing the ink added to its printed surface Pf. The heating unit 16 is covered with a cover 17, and the cover 17 has a protection function of protecting the heating unit 16 and a heat reflection function of reflecting the heat generated by the heating unit 16 to the print medium P side. The heating temperature of the heating unit 16 can be set based on the fixability of the ink and the productivity of the printed product, etc.

[0045] The heating mode of the heating unit 16 is not limited to heating from the printed surface Pf side (see Figure 2 ), and it can also be heated from the back surface Pb on the opposite side. In this case, the heating unit 16 is arranged, for example, on the downstream side (+Y direction side) of the platen 12 and on the lower side (-Z direction side) of the guide unit 19 for guiding the printed print medium P.

[0046] For the heating unit 16, a fuse heater, a halogen heater, or a known non-contact heat conduction heater can be used. Other known heaters such as a warm air heater can be used. In addition, a plurality of heating units 16 can be provided.

[0047] As will be described in detail later, each color ink used in the printing device 10 may contain pigments, resin fine particles, and a water-soluble organic solvent. The heating unit 16 melts the resin fine particles in the ink by heating and evaporates the water-soluble organic solvent in the ink, thereby fixing the pigments on the printing medium P.

[0048] The ink containing resin fine particles has characteristics for improving wear resistance or fixing properties. Therefore, it is preferable to set the heating temperature of the heating unit 16 to be equal to or higher than the minimum film-forming temperature of the resin fine particles. In addition, the heating temperature needs to be set so that liquid components such as the water-soluble organic solvent in the ink are substantially evaporated. Therefore, the heating unit 16 can be configured to form a temperature distribution in the conveyance direction of the printing medium P that can sufficiently ensure a heating time for sufficiently supplying the energy required for evaporation.

[0049] Although not shown here, the printing device 10 further includes a predetermined recovery unit, and the recovery unit can restore the liquid discharge function of each ejection port 32 in the print head 24 and satisfactorily maintain the discharge state of the liquid from each ejection port 32. The recovery unit can be provided near the end of the print head 24 in the scanning direction (X direction). For example, the recovery unit is provided adjacent to the platen 12. Examples of the recovery unit are a wiping unit for wiping the ejection port surface 34 and a cover for protecting the ejection port surface 34, but other known recovery units can be provided.

[0050] <Optical sensor>

[0051] As Figure 2 shown, the printing device 10 includes a reflection optical sensor 200 capable of detecting the optical characteristics on the printed product. The control unit 100 acquires the optical density (OD) value as the reflection optical characteristic on the printing medium P based on the detection result of the optical sensor 200.

[0052] The installation position of the optical sensor 200 is not limited to Figure 2 the example shown, and the optical sensor 200 can be provided on the +X direction side or -X direction side of the carriage 22, or can be provided on the +Y direction side or -Y direction side. Alternatively, the optical sensor 200 can be provided independently of the carriage 22 and arranged to be movable in the X direction, or can extend in the X direction through the width of the printing medium P.

[0053] Figure 3A is a schematic diagram for explaining an example of the configuration of the optical sensor 200. Figure 3B is a schematic diagram showing the detection spot of the optical sensor 200.

[0054] The optical sensor 200 is fixed to the carriage 22 such that the detection area or measurement area is located on the +Y direction side with respect to the ejection port array (nozzle array) 33 of the print head 24 (see Figure 4 ). The lower surface 200a of the optical sensor 200 is located at a position coinciding with the ejection port surface 34 in the Z direction, or on the +Z direction side with respect to the ejection port surface 34.

[0055] The optical sensor 200 includes a light emitting unit 302 (e.g., an LED) that generates visible light such as red light, green light, or blue light, and a light receiving unit 304 (e.g., a photodiode) that detects the visible light. The light emitting unit 302 and the light receiving unit 304 are provided on the lower surface 200a of the optical sensor 200. The light emitting unit 302 irradiates the print medium P with light, and the light receiving unit 304 receives and detects the light reflected by the print medium P. That is, the irradiation light 306 from the light emitting unit 302 is diffusely reflected by the print medium P, and the associated reflected light 308 is detected by the light receiving unit 304. Note that the diameter of the detection spot 310 where the irradiation light 306 is diffusely reflected by the print medium P is, for example, about 3 mm.

[0056] Via a wiring portion (not shown) such as a flexible cable, the detection signal detected by the light receiving unit 304 is transmitted as an analog signal corresponding to the light amount of the reflected light 308 to a control circuit on the electric board of the printing device 10. In the control circuit, the detection signal is converted into a digital signal by an A / D converter.

[0057] When detecting the optical characteristics of an adjustment pattern (see Figure 6A etc.), the conveyance of the print medium P in the Y direction and the movement of the carriage 22 to which the optical sensor 200 is attached in the X direction are alternately performed. The optical sensor 200 detects the optical reflectance (i.e., the density of the print pattern) on the printed product while synchronizing the execution timing based on the position signal obtained by the encoder 30. For example, in the case of a white or relatively light print pattern, the reflection intensity is large / strong, and in the case of a black or relatively dark print pattern, the reflection intensity is small / weak.

[0058] <Print head>

[0059] Figure 4FIG. 0 is a schematic view showing the ejection port surface 34 of the print head 24 as seen in the +Z direction. One or more ejection port arrays 33 are formed on the ejection port surface 34. In each of the one or more ejection port arrays 33, a plurality of ejection ports 32 configured to eject corresponding liquids are arranged along the Y direction. Here, five ejection port arrays 33K, 33C, 33M, 33Y, and 33RCT for ejecting K ink, C ink, M ink, Y ink, and reaction liquid RCT are formed in the X direction. Note that the arrangement order of the five ejection port arrays 33K, etc. is not limited to Figure 4 the example shown, and the ejection port arrays may be arranged in other orders.

[0060] In this embodiment, in each ejection port array 33, 1,280 ejection ports 32 are arranged at intervals of 1200 dpi in the Y direction, and the ejection amount of the liquid (color ink or reaction liquid) ejected from a single ejection port 32 at one time is approximately 4.5 pl (picoliters). In addition, a tank (not shown) for storing the corresponding liquid is connected to each ejection port array 33, and the corresponding liquid is supplied from the tank to the ejection port array 33. Note that the tank may be integrated with the print head 24 or may be detachable from the carriage 22.

[0061] <Color Ink>

[0062] As the color ink, generally, pigment ink containing pigments and / or water-soluble resin fine particles ink that does not contain pigments or contains a very small amount of pigments can be used. The resin fine particles adhere the print medium P and the colorant to each other, and improve the abrasion resistance or fixing property of the printed image. The resin fine particles can be melted by heating, and the resin fine particles are formed into a film and the solvent in the ink is dried by the heating unit 16. In this embodiment, the resin fine particles are polymer fine particles dispersed in a liquid. The polymer fine particles may be resin fine particles obtained by homopolymerizing a monomer having a dissociative group or copolymerizing multiple types of monomers (so-called self-dispersing resin fine particle dispersion).

[0063] In order to obtain desired characteristics, surfactants, defoaming agents, preservatives, or fungicides, etc. can be added to the color ink. As the surfactant, a penetrant for improving the permeability of the color ink to the inkjet dedicated print medium P can be used. In this embodiment, the surfactant is selected and adjusted so that the surface tension of each color ink is 30 dyn / cm or less, and the surface tension difference between the color inks is 2 dyn / cm or less. That is, the surface tension of all color inks is set in the range of 28 dyn / cm to 30 dyn / cm.

[0064] To prevent impurities from leaching out of the constituent members in the printing device 10 or in contact with the color ink in the print head 24, deterioration of the constituent members, and / or a decrease in the solubility of the pigment dispersion resin in the color ink, it is preferable that the pH of the color ink falls within the range of 7.0 to 10.0. Since each color ink used in this embodiment contains an anionic colorant, the pH is stabilized on the alkaline side and the value falls within the range of 8.5 to 9.5.

[0065] <Reaction liquid>

[0066] The reaction liquid RCT contains reaction components that react with the colorants of the color ink, and when the reaction liquid RCT comes into contact with the color ink, it cures or thickens the color ink, and while suppressing bleeding of the color ink on the printing medium P, it fixes the color ink to the printing medium P. More specifically, the reaction liquid contains reaction components that react with the pigments in the color ink and cause the pigments to coagulate or gel, and / or reaction components that react with the resin particles and render them insoluble.

[0067] The reaction components are, for example, components that can disrupt the dispersion stability in the color ink by the action of ionic groups when mixed with the color ink containing components dispersed in a liquid. Examples of the reaction components are organic acids such as glutaric acid. Based on the total mass of the composition in the reaction liquid RCT as a reference, the content of the organic acid in the reaction liquid RCT preferably falls within the range of 3.0 mass% to 90.0 mass%, and more preferably within the range of 5.0 mass% to 70.0 mass%. In addition, as with the color ink, it is also preferable to add a surfactant to the reaction liquid RCT.

[0068] <Execution control of printing operation>

[0069] Figure 5 is a block diagram for explaining the control system of the printing device 10. The control unit 100 is configured to control the entire system of the printing device 10 and includes a central processing unit (CPU) 102, a read-only memory (ROM) 104, a random access memory (RAM) 106, and a memory 108.

[0070] The CPU 102 performs drive control of the respective elements of the printing device 10 and processing of the image data input to the printing device 10 based on a predetermined program. The ROM 104 stores programs that the CPU 102 can execute. The RAM 106 stores information such as parameters and data required for drive control of the printing device 10. The memory 108 stores information such as adjustment patterns and mask patterns, which will be described later.

[0071] In addition, the control unit 100 includes an input / output port 110 and is connected to elements external to the control unit 100 via the input / output port 110.

[0072] For example, the control unit 100 is connected to the interface circuit 112 via the input / output port 110, and is connected to the host device 114 via the interface circuit 112. The control unit 100 is also connected to the operation panel 124 that can be operated by the user via the input / output port 110. The user can input desired image data to the printing device 10 via the host device 114, and can also input other information required for printing to the printing device 10 via the host device 114 and the operation panel 124.

[0073] In addition, the control unit 100 is connected to the motor driver 116 via the input / output port 110, and performs drive control of the motor 118 via the motor driver 116. The motor 118 includes various types of motors provided in the printing device 10, such as a carriage motor for moving the carriage 22 and a conveyance motor for driving the above-described conveyance unit.

[0074] The control unit 100 is also connected to the head driver 120 via the input / output port 110, and performs drive control of the print head 24 via the head driver 120.

[0075] The control unit 100 is also connected to the drive circuit 122 via the input / output port 110, and performs drive control of the heating unit 16 via the drive circuit 122.

[0076] In addition, the control unit 100 is connected to the optical sensor 200 via the input / output port 110, performs drive control of the optical sensor 200, and thereby detects the optical characteristics of the adjustment pattern (to be described later) on the printed product based on the signal from the optical sensor 200. From this viewpoint, it can be said that in this embodiment, the control unit 100 and the optical sensor 200 serve as a detection unit capable of detecting optical characteristics.

[0077] When printing is executed, in the control unit 100, the CPU 102 converts the image data input from the host device 114 into print data and stores it in the RAM 106. More specifically, for each of the RGB data corresponding to red, green, and blue in the RGB data, the CPU 102 acquires image data indicating 8-bit information having 256 values (0 to 255). Thereafter, the CPU 102 performs color conversion processing for converting the image data into multi-value data corresponding to various types of inks (K, C, M, and Y corresponding to color inks in this embodiment) in the printing device 10. That is, in the color conversion processing, multi-value data indicating 8-bit information having 256 values (0 to 255) is generated, where the 8-bit information indicates the hues of K, C, M, and Y in each of the plurality of pixels.

[0078] Next, the quantization of the above multi-value data is performed, and the CPU 102 generates quantized data (binary data), which indicates 1-bit information having two values (0 or 1) for determining the ejection or non-ejection of each of the K, C, M, and Y inks for each pixel. As an example of the quantized data generation process, well-known quantization methods such as error diffusion method, dither method, or index method can be used.

[0079] Thereafter, the CPU 102 performs an allocation process for allocating the above quantized data to each area of one scan operation of the print head 24, so as to achieve the above multi-pass printing. Thus, print data is generated, which indicates 1-bit information having two values (0 or 1) for determining the ejection or non-ejection of each of the K, C, M, and Y inks for each pixel, and corresponds to each scan of the print head 24. The allocation process can be performed using a mask pattern that indicates the permission or non-permission of liquid ejection from each ejection port 32 in each scan operation.

[0080] In this way, the control unit 100 serves as a print control unit that performs desired printing based on the results of the above data processing and performs drive control of the components in the printing apparatus 10 (mainly the print unit 14 (print head 24) and the conveyance unit (not shown)). Note that the above data processing can be at least partially performed by the host device 114.

[0081] <Offset of liquid ejection position>

[0082] With the above configuration, the printing apparatus 10 performs a printing operation based on the print data. That is, the print head 24 ejects liquid while reciprocating in the X direction by the carriage 22, thereby performing printing on the print medium P.

[0083] During printing, color ink and a reaction liquid are ejected in a predetermined amount in the same area. Thus, the reaction liquid contacts the color ink in a predetermined ratio, and this can suppress bleeding of the color ink that significantly occurs especially on a non-absorbent (or almost non-absorbent) print medium P. In addition, when the print medium P onto which the color ink and the reaction liquid are ejected passes through the heating unit 16, the color ink is heated and dried, thereby promoting fixing of the ink even on a non-absorbent print medium P.

[0084] As described above, it is necessary to discharge the color ink and the reaction liquid onto the same area. Therefore, the printing apparatus 10 needs to evaluate the relative displacement of the discharge position of the reaction liquid with respect to the discharge position of each color ink and obtain the displacement amount. Here, the discharge position indicates the landing position of the droplet on the printing medium P. In the following description, the relative displacement of the discharge position of the liquid will sometimes be simply referred to as "position displacement". In addition, this amount will sometimes be simply referred to as "position displacement amount". In particular, in the configuration in which the carriage 22 reciprocates in the X direction while discharging the liquid, it is necessary to obtain the position displacement amount in the X direction.

[0085] The acquisition process for obtaining such a position displacement amount can be executed, for example, by the user instructing the start of the acquisition process via the host device 114 or the operation panel 124. Thereafter, for example, the control unit 100 can calculate or specify a correction value for correcting the liquid discharge timing based on the obtained position displacement amount. The printing operation is performed by correcting the liquid discharge timing based on the correction value calculated thereby and adjusting the discharge position.

[0086] <Adjustment pattern>

[0087] The adjustment of the discharge position of the color ink (mainly a series of operations of obtaining the above-mentioned position displacement amount, calculating a correction value for correcting the position displacement amount, and concomitantly correcting the discharge timing) can be performed using a known adjustment pattern. This can be relatively easily achieved, for example, by the detection of the optical sensor 200 or the visual observation of the user.

[0088] On the other hand, as will be described in detail later, the discharge position of the reaction liquid is adjusted by printing or forming the pattern of the color ink and the pattern of the reaction liquid in an overlapping state and detecting the difference in the reaction degree of the reaction liquid using the optical sensor 200 or visually observing the difference by the user.

[0089] However, the reaction liquid is usually colorless and transparent, and its discharge position may change between the forward path (for example, scanning in the -X direction) and the reverse path (for example, scanning in the +X direction). In addition, as will be described in detail later, when adjusting the reaction liquid, it is necessary to print the pattern of the reaction liquid before the pattern of the color ink. For these reasons, the adjustment of the reaction liquid is usually difficult compared to the case of the color ink.

[0090] Figures 6A to 6C Examples of sub-patterns that form the adjustment pattern to be described later are shown. Figures 7A to 7D A partial enlarged view of a region of a total of 64 pixels including 8 pixels in the X direction and 8 pixels in the Y direction is shown as an example of the detailed pattern of the sub-pattern.

[0091] Figure 6AShows a sub-pattern 61 formed by one of the color inks. In this embodiment, the sub-pattern 61 is formed by K ink, but it can be formed by other color inks. As Figure 7A shown, the sub-pattern 61 is printed with a relatively high dot density and uniformly.

[0092] Figure 6B Shows a sub-pattern 62 formed by the reaction liquid. The sub-pattern 62 is formed by alternately arranging a region Sr1 with a relatively low dot density and a region Sr2 with a relatively high dot density. In the region Sr1 of the sub-pattern 62, as Figure 7B shown, printing is performed with a relatively low dot density and uniformly. In addition, in the region Sr2, as Figure 7C shown, printing is performed with a relatively high dot density and uniformly. According to this example, in a region of a total of 64 pixels, 13 pixels of dots are discretely formed in the example as Figure 7B shown, and dots are formed in the entire region in the example as Figure 7C shown. However, the dot density is relative, and the dot density is not limited to this example.

[0093] Figure 6C Shows another sub-pattern 73 formed by the reaction liquid. As will be described in detail later, the sub-pattern 73 is used as an underlying pattern configured to appropriately achieve the printing of the adjustment pattern. As Figure 7D shown, the sub-pattern 73 is printed with a relatively low dot density and uniformly.

[0094] Note that "uniform" here includes that there is no local deviation in the dot density when evaluating a wide area, and for the difference in the reaction degree of the reaction liquid, it does not prevent the detection of the optical sensor 200 and / or the visual observation of the user. Therefore, the uniform pattern does not have to always be a dot pattern according to strict regularity.

[0095] In addition, for easier understanding, for the sub-pattern 62, two regions Sr1 and Sr2 are illustrated. It is only necessary that adjacent regions have different dot densities, and it is only necessary that the number of types of regions is two or more.

[0096] As Figure 8 shown, consider the case of printing an adjustment pattern 91 by overlapping the uniform sub-pattern 61 of K ink in the above sub-pattern and the sub-pattern 62 in which regions Sr1 and Sr2 are alternately arranged. When the adjustment pattern 91 is printed by overlapping the sub-pattern 61 and the sub-pattern 62, the reaction liquid of the sub-pattern 62 reacts with the K ink of the sub-pattern 61. At this time, since the reaction degree in the region Sr2 with a relatively high dot density is greater than the reaction degree in the region Sr1 with a relatively low dot density, the optical characteristics between the region Sr1 and the region Sr2 change. More specifically, the reflection intensity in the region Sr1 is higher than the reflection intensity in the region Sr2.

[0097] The change in the reflection intensity between region Sr1 and region Sr2 indicates the boundary between region Sr1 and region Sr2 and can be detected by the above-described optical sensor 200 (see FIG. 3), but can also be visually recognized by the user's visual observation.

[0098] As Figure 8 the adjustment pattern 91 in Figure 9 shows adjustment patterns 101 and 102 that take into account the forward path (e.g., scanning in the -X direction) and the reverse path (e.g., scanning in the +X direction). For example, adjustment pattern 101 is printed in the forward path and adjustment pattern 102 is printed in the reverse path. As described above or as Figure 9 shown, the discharge position of the reaction solution may vary between the forward path and the reverse path. The position offset can be obtained based on the change in the reflection intensity between region Sr1 and region Sr2 by detection by the optical sensor 200 (or by the user's visual observation). A correction value is calculated based on the obtained position offset, and the discharge timing of the reaction solution in one of the forward path and the reverse path (e.g., the reverse path) can be corrected based on the correction value so as to be consistent with the discharge timing of the reaction solution in the other path (e.g., the forward path).

[0099] Figure 10 and Figure 11 each show an example of a method of printing or forming the adjustment pattern according to this embodiment.

[0100] Figure 10 shows adjustment pattern 121 for the forward path when discharging the reaction solution in the forward path. Adjustment pattern 121 is printed by some parts of the ejection port array 33, and in this embodiment, adjustment pattern 121 is printed by the regions on one end side and the other end side in the Y direction (regions other than the central part) of ejection port array 33K and ejection port array 33RCT. These printing regions are defined as region R1 and region R3. Adjustment pattern 121 includes sub-pattern 123 formed by K ink and sub-pattern 124 formed by the reaction solution. The sub-pattern 123 formed by K ink can be printed in any of the forward path and the reverse path, but the sub-pattern 124 formed by the reaction solution is printed in the forward path.

[0101] Figure 11Shows the adjustment pattern 122 for the reverse path when discharging the reaction liquid in the reverse path. The adjustment pattern 122 is printed by other parts in the nozzle array 33, and in this embodiment, the adjustment pattern 122 is printed by the regions at the centers in the Y direction in the nozzle array 33K and the nozzle array 33RCT. The printing area is defined as area R2. The adjustment pattern 122 includes a sub-pattern 125 formed by K ink and a sub-pattern 126 formed by the reaction liquid, and as will be described in detail later, also includes a sub-pattern 137 formed by the reaction liquid. The sub-pattern 125 formed by K ink can be printed in any of the forward path and the reverse path, but the sub-pattern 126 formed by the reaction liquid is printed in the reverse path. In addition, the sub-pattern 137 formed by the reaction liquid can be printed in any of the forward path and the reverse path.

[0102] The patterns printed in regions R1 and R3 of the sub-pattern 123 are substantially the same as the pattern printed in region R2 of the sub-pattern 125, and are each indicated as pattern 1211. Pattern 1211 corresponds to Figure 6A the sub-pattern 61 shown.

[0103] The patterns printed in regions R1 and R3 of the sub-pattern 124 are substantially the same as the pattern printed in region R2 of the sub-pattern 126, and are each indicated as pattern 1212. Pattern 1212 is formed by alternately arranging regions Sr1 and Sr2, and pattern 1212 corresponds to Figure 6B the sub-pattern 62 shown.

[0104] The pattern printed in region R2 of the sub-pattern 137 is indicated as pattern 1213. Pattern 1213 corresponds to Figure 6C the sub-pattern 73 shown.

[0105] Regions R1 to R3 can be considered as regions obtained by dividing the unit region, which is the region of one scanning operation of the print head 24, in the Y direction, and the above adjustment pattern 121 and adjustment pattern 122 are printed in this unit region by multiple scanning operations of the print head 24. The patterns 1211, 1212, and 1213 for forming the adjustment pattern 121 and adjustment pattern 122 are printed by one scanning operation (forward path or reverse path).

[0106] <Underlying pattern>

[0107] In this embodiment in which multi-pass printing is performed, in the case of normal printing (the case of generating a printed product formed of characters, numbers, symbols, graphics, photographs, etc., and usually printing a desired document file according to an instruction from the host device 114), the operations of printing by discharging the reaction liquid and the color ink in the forward path and the operations of printing by discharging the reaction liquid and the color ink in the reverse path are repeated a plurality of times in the same unit area, and most of the ejection ports 32 are not driven simultaneously. For this reason, which of the color ink and the reaction liquid is discharged first onto the print medium P usually does not become a problem.

[0108] On the other hand, when printing the adjustment pattern, the number of scanning operations of the print head 24 per unit area is smaller than that in normal printing, and each pattern in the above-described pattern 1211, etc. is usually printed by one scanning operation. Therefore, if the pattern of the color ink (e.g., pattern 1211) is printed first, the droplets of the color ink may flow on the print medium P before the pattern of the subsequent reaction liquid (e.g., pattern 1212) is printed. Since this flow may destroy the uniformity of the pattern of the color ink, it is difficult to print the adjustment pattern appropriately, and it is difficult to obtain the position shift amount of the reaction liquid based on the change in the reflection intensity between the region Sr1 and the region Sr2.

[0109] Therefore, when printing the adjustment pattern for adjusting the discharge position of the reaction liquid, it is necessary to print the pattern of the reaction liquid before the pattern of the color ink.

[0110] Reference Example

[0111] Figure 12A and Figure 12B Examples of methods for printing the adjustment pattern are shown as reference examples. For the print head 24, the ejection port array 33RCT capable of discharging the reaction liquid RCT is located on the downstream side of the ejection port array 33K capable of discharging the K ink in the forward path.

[0112] Figure 12A A state is shown in which, in the forward path, the ejection port array 33RCT is driven before the ejection port array 33K, and thus the reaction liquid RCT is discharged first onto the print medium P, and then the K ink is discharged.

[0113] Figure 12B A state is shown in which, in the reverse path, the ejection port array 33K is driven before the ejection port array 33RCT, and thus the K ink is discharged first onto the print medium P, and then the reaction liquid RCT is discharged.

[0114] In this reference example, since the K ink, which is an example of the color ink, is discharged before the reaction liquid RCT, as described above, the droplets of the color ink may flow, and it may be difficult to print the adjustment pattern appropriately.

[0115] First example

[0116] As in the above reference example (see Figure 12A and Figure 12B ), Figure 13A and Figure 13B show another example of a method for printing an adjustment pattern as the first example. Figure 13A Same as Figure 12A and the description thereof will be omitted here.

[0117] On the other hand, in Figure 13B , the ejection port array 33RCT is driven in the reverse path, and the ejection port array 33K is driven in the subsequent forward path. Therefore, the reaction liquid RCT is first discharged onto the print medium P, and then the K ink is discharged. Note that Figure 13B the "×" in

[0118] indicates that the drive is suppressed.

[0119] Therefore, in this example, since the reaction liquid RCT is discharged before the K ink in both the forward path and the reverse path, the adjustment pattern can be printed appropriately.

[0120] Figure 14 are schematic perspective views for respectively explaining the adjustment pattern 121 for the forward path printed in the region R1 and the adjustment pattern 122 for the reverse path printed in the region R2 in the first print mode Md1. Note that the region R3 is the same as the region R1, and the description thereof will be omitted here. In each enlarged schematic view, the pattern shown on the lower side is printed below the pattern shown on the upper side.

[0121] In the region R1, the pattern 1212 of the reaction liquid is printed in the forward path of the print head 24 indicated by the arrow A11, and substantially simultaneously, the pattern 1211 of the color ink is printed in the forward path of the print head 24 indicated by the arrow A12. Here, the arrow A11 and the arrow A12 correspond to the same scanning operation of the print head 24. Since the ejection port array 33RCT is located on the downstream side of the ejection port array 33K in the forward path, the pattern 1212 is printed before the pattern 1211.

[0122] On the other hand, in the region R2, the pattern 1212 of the reaction liquid is printed in the reverse path of the print head 24 indicated by the arrow A21, and the pattern 1211 of the color ink is printed in the subsequent forward path indicated by the arrow A22. Therefore, in the region R2, the pattern 1212 is also printed before the pattern 1211.

[0123] According to the printing mode Md1, in both the region R1 and the region R2 (and also in the region R3), the pattern 1212 of the reaction liquid is printed before the pattern 1211 of the color ink, that is, the pattern 1212 is formed below the pattern 1211. Therefore, according to the printing mode Md1, it is possible to prevent the droplets of the color ink of the pattern 1211 from flowing on the printing medium P and to appropriately print the adjustment pattern.

[0124] The printing of the pattern 1211 etc. can be sequentially performed for each of the regions R1 to R3, but the printing of the pattern 1211 etc. can also be performed simultaneously. When printing the regions R1 to R3 simultaneously, it can be said that the printing can be achieved, for example, by one reciprocating movement on the reverse path indicated by the arrow A21 and on the forward paths indicated by the arrows A11, A12, and A22.

[0125] Second example

[0126] As in the above reference example and the first example (see Figure 12A and Figure 12B and Figure 13A and Figure 13B ), Figure 15A and Figure 15B show a second example in which the flow of the droplets of the color ink can be prevented. Figure 15A Same as Figure 12A and Figure 13A , and the description thereof is omitted here.

[0127] On the other hand, Figure 15B shows that: the ejection port array 33K and the ejection port array 33RCT are driven in the reverse path, but the ejection port array 33RCT is driven in the forward path before that. In the forward path, a uniform pattern 1213 of the reaction liquid is formed as the underlying pattern, and in the subsequent reverse path, the pattern 1211 of the color ink and the pattern 1212 of the reaction liquid are sequentially printed.

[0128] As described above, the pattern 1213 corresponds to the sub-pattern 73 shown in Figure 6C , and is printed uniformly with a relatively low dot density (see Figure 7D ). It is only necessary for the pattern 1213 to have a dot density capable of preventing the above-mentioned flow and to suppress the influence on the pattern 1211 of the color ink compared to the pattern 1212 of the reaction liquid. That is, for the dot density of the pattern 1213, it is only necessary that the optical sensor 200 can detect (or visually recognize by the user's visual observation) the change in the reflection intensity that may occur between the region Sr1 and the region Sr2 due to the difference in the reaction degree.

[0129] From this perspective, referring again to Figures 7B to 7D, the dot density of the sub-pattern 73 is preferably at least lower than the dot density of the region Sr2 of the sub-pattern 62, and more preferably lower than the dot density of the region Sr1.

[0130] In this example, the uniform pattern 1213 of the reaction liquid is used as the underlying pattern, and this underlying pattern is used to appropriately print the adjustment pattern formed by the patterns 1211 and 1212 to be printed thereafter.

[0131] In the following description, the adjustment pattern printing mode will be defined as the second printing mode Md2.

[0132] As in the above first example (see Figure 14 ), Figure 16 is a schematic perspective view for separately illustrating the adjustment pattern 121 for the forward path printed in the region R1 and the adjustment pattern 122 for the reverse path printed in the region R2 in the printing mode Md2. Note that the region R1 (and the region R3) is the same as in the first example, and the description thereof will be omitted here.

[0133] On the other hand, in the region R2, first, the uniform pattern 1213 of the reaction liquid is printed in the forward path of the print head 24 indicated by the arrow A31. Then, in the subsequent reverse path, as shown by the arrow A32, the pattern 1211 of the color ink is printed, and as shown by the arrow A33, the pattern 1212 of the reaction liquid is printed substantially simultaneously. The arrow A32 and the arrow A33 correspond to the same scanning operation of the print head 24. Since the ejection port array 33K is located on the downstream side of the ejection port array 33RCT in the reverse path, the pattern 1211 of the color ink is printed before the pattern 1212 of the reaction liquid. However, since the uniform pattern 1213 of the reaction liquid is formed as the underlying pattern in the forward path A31, the flow of the droplets of the color ink can be prevented.

[0134] As in the above first example, the printing of the patterns 1211, etc. can be sequentially performed for each of the regions R1 to R3, but the printing of the patterns 1211, etc. can be performed simultaneously. When printing the regions R1 to R3 simultaneously, it can be said that this printing can be achieved, for example, by one reciprocating movement on the forward paths indicated by the arrows A11, A12, and A31 and on the reverse paths indicated by the arrows A32 and A33.

[0135] Third example

[0136] According to the printing mode Md1 (first example), on both the regions R1 and R2 (and the region R3), the pattern 1212 of the reaction liquid is printed before the pattern 1211 of the color ink, that is, the pattern 1212 is formed below the pattern 1211.

[0137] However, since the pattern 1212 of the reaction liquid has a relatively high dot density in the region Sr2, depending on the type of the printing medium P, droplets of the reaction liquid may flow on the printing medium P before the pattern 1211 of the color ink is printed.

[0138] Therefore, a uniform pattern 1213 of the reaction liquid can also be printed in the region R1 (and the region R3). That is to say, in Figure 11 the sub-pattern 137 shown, the pattern 1213 can be formed in all regions R1 to R3. Thus, the pattern 1213 also serves as an underlying pattern for preventing the flow of droplets of the reaction liquid in the pattern 1212.

[0139] In the following description, adjusting the pattern printing mode will be defined as the third printing mode Md3.

[0140] As in the above first example and second example (see Figure 14 and Figure 16 ), Figure 17 FIG. is a schematic perspective view for respectively illustrating the adjusting pattern 121 for the forward path printed in the region R1 and the adjusting pattern 122 for the reverse path printed in the region R2 in the printing mode Md3.

[0141] In the printing mode Md3, for the region R1, the patterns 1212 and 1211 are printed in the forward path of the print head 24 indicated by the arrows A11 and A12. However, in the previous forward path, as indicated by the arrow A10, the pattern 1213 was printed. This also applies to the region R3. The region R2 is the same as in the second example, and the description thereof will be omitted here.

[0142] As in the above first example and second example, the printing of the pattern 1211 etc. can be sequentially performed for each of the regions R1 to R3, but the printing of the pattern 1211 etc. can be performed simultaneously. When printing the regions R1 to R3 simultaneously, it can be said that the printing can be achieved, for example, by 1.5 reciprocating movements on the forward path indicated by the arrows A10 and A31, on the reverse path indicated by the arrows A32 and A33, and on the forward path indicated by the arrows A11 and A12.

[0143] <First Embodiment>

[0144] Figure 18A flowchart showing an acquisition process for obtaining the positional offset of the reaction liquid between the forward path and the reverse path based on one of the first to third examples (e.g., the adjustment pattern printed in the printing mode Md3). A series of processes shown in this flowchart can be performed by deploying the corresponding program read from the ROM 104 onto the RAM 106 by the CPU 102 and executing the program, and some / all of the processes can be executed by a semiconductor integrated circuit such as an ASIC. That is, the functions to be described here can be implemented by hardware or software.

[0145] In step S1501 (hereinafter simply referred to as "S1501", and this applies to the remaining steps to be described later), the CPU 102 reads the corresponding image data from the memory 108 and prints the adjustment pattern 121 and the adjustment pattern 122.

[0146] In S1502, the CPU 102 detects the optical characteristics of each adjustment pattern in the printed adjustment pattern. The detection of the optical characteristics is based on the reflection intensities of the adjustment pattern 101 and the adjustment pattern 102 detected by the optical sensor 200 (see Figure 8 and Figure 9 ). The detection of the optical characteristics can be performed by visual observation by the user, and in this case, this step is omitted.

[0147] In S1503, the CPU 102 obtains the positional offset of the reaction liquid between the forward path and the reverse path based on the obtained optical characteristics of the adjustment pattern (see Figure 9 ).

[0148] In S1504, the CPU 102 calculates a correction value for correcting the discharge timing of the reaction liquid based on the obtained positional offset (see Figure 19 ).

[0149] In S1505, the CPU 102 determines the discharge timing of the reaction liquid based on the calculated correction value so that the reaction liquid can be discharged to an appropriate position.

[0150] Figure 19 An example of the adjustment pattern 141 printed based on each of the first to third examples is shown. In this example, the adjustment pattern 141 includes nine adjustment patterns 1411 to 1419. The adjustment patterns 1411 to 1419 are formed such that the X-direction offset of the adjustment pattern 122 for the reverse path printed in the region R2 with respect to the adjustment pattern 121 for the forward path printed in the regions R1 and R3 changes in increments of one pixel. That is:

[0151] In adjustment pattern 1411, adjustment pattern 122 is offset by four pixels (-4 pixels) in the -X direction relative to adjustment pattern 121;

[0152] In adjustment pattern 1412, adjustment pattern 122 is offset by three pixels (-3 pixels) in the -X direction relative to adjustment pattern 121;

[0153] In adjustment pattern 1413, adjustment pattern 122 is offset by two pixels (-2 pixels) in the -X direction relative to adjustment pattern 121;

[0154] In adjustment pattern 1414, adjustment pattern 122 is offset by one pixel (-1 pixel) in the -X direction relative to adjustment pattern 121;

[0155] In adjustment pattern 1415, adjustment pattern 122 is not offset relative to adjustment pattern 121 in the X direction, i.e., the adjustment patterns are aligned with each other in the X direction (no offset);

[0156] In adjustment pattern 1416, adjustment pattern 122 is offset by one pixel (+1 pixel) in the +X direction relative to adjustment pattern 121;

[0157] In adjustment pattern 1417, adjustment pattern 122 is offset by two pixels (+2 pixels) in the +X direction relative to adjustment pattern 121;

[0158] In adjustment pattern 1418, adjustment pattern 122 is offset by three pixels (+3 pixels) in the +X direction relative to adjustment pattern 121; and

[0159] In adjustment pattern 1419, adjustment pattern 122 is offset by four pixels (+4 pixels) in the +X direction relative to adjustment pattern 121.

[0160] In adjustment pattern 1415, between adjustment pattern 124 and adjustment pattern 126, region Sr1 (or region Sr2) is aligned with each other in the X direction and is located in one row in the Y direction. On the other hand, for the remaining adjustment patterns (e.g., adjustment pattern 1411), between adjustment pattern 124 and adjustment pattern 126, region Sr1 (or region Sr2) is not aligned with each other in the X direction.

[0161] Note that in Figure 19 the example shown, the X-direction offset between adjustment pattern 121 and adjustment pattern 122 increases by one pixel between adjustment patterns 1411 to 1419. However, the amount of change in the offset is not limited to this example.

[0162] Based on the adjustment pattern 141, the offset of the discharge position of the reaction liquid in the reverse path (scanning in the +X direction) relative to the discharge position of the reaction liquid in the forward path (scanning in the -X direction) can be evaluated. For example, in the adjustment pattern 1415, there is substantially no position offset, and between the adjustment patterns 121 and 122, the regions Sr1 are aligned with each other in the X direction.

[0163] On the other hand, if a position offset occurs, in other adjustment patterns except for the adjustment pattern 1415 (i.e., in the adjustment patterns 1411 to 1414 and the adjustment patterns 1416 to 1419), between the adjustment patterns 121 and 122, the regions Sr1 are aligned with each other in the X direction.

[0164] For example, if the position offset amount is +3 pixels, in the adjustment pattern 1412 where the initial position offset amount is -3 pixels, the regions Sr1 are aligned with each other between the adjustment patterns 121 and 122. In this case, a correction value corresponding to -3 pixels is obtained, the discharge timing in the reverse path is corrected, and the discharge position is corrected by three pixels in the -X direction.

[0165] In the above-described manner, the relative offset amount of the discharge position of the reaction liquid between the forward path and the reverse path can be obtained based on the printing result of the adjustment pattern 141, and the correction value for correcting the position offset can be calculated.

[0166] <Second Embodiment>

[0167] When printing the adjustment pattern 141, the above-described printing modes Md1 to Md3 are selected as needed, and the selection can be mainly based on the type of the printing medium P. Here, it is assumed that the printing modes Md1 and Md3 are selected, but as other embodiments, the printing mode Md2 can be combined, or other equivalent printing modes can also be combined.

[0168] Here, the printing modes Md1 and Md3 will be compared. In the printing mode Md3, for example, the consumption amount of the reaction liquid is large. For this reason, the printing mode Md1 is selected as the standard, but if it is difficult to evaluate the position offset amount of the reaction liquid in the printing mode Md1, the printing mode Md3 can be selected.

[0169] Figure 20 A flowchart showing the acquisition process according to the second embodiment is shown. Except for S2101, S2102, and S2106, the steps illustrated here are the same as those in the above-described first embodiment (see Figure 18 ) and the description thereof will be omitted.

[0170] In S2101, the CPU 102 prints the adjustment pattern 121 and the adjustment pattern 122 in the printing mode Md1.

[0171] In S2102, the CPU 102 detects the optical characteristics of the printed adjustment pattern (see Figure 8 and Figure 9 ), and determines whether the change in the reflection intensity between the region Sr1 and the region Sr2 can be specified (whether the boundary between the region Sr1 and the region Sr2 can be specified) based on the detection result. For example, if the boundary between the region Sr1 and the region Sr2 is unclear, the change rate of the reflection intensity is moderate, and thus this step is performed based on whether the change rate of the reflection intensity satisfies the standard. Note that this step is implemented by the detection of the optical sensor 200, but can be performed by the visual observation of the user.

[0172] If the change in the reflection intensity between the region Sr1 and the region Sr2 can be specified, the process proceeds to S1503; otherwise, the process proceeds to S2106.

[0173] In S2106, the CPU 102 prints the adjustment pattern 121 and the adjustment pattern 122 in the printing mode Md3, and then proceeds to S1503.

[0174] According to this embodiment, the same effect as that in the first embodiment can be obtained, and additionally, since the adjustment pattern is printed only in the printing mode Md3 when needed, it is beneficial to avoid unnecessary consumption of the reaction liquid.

[0175] <Third Embodiment>

[0176] Even if the type of the printing medium P is specified in advance and the printing modes Md1 and Md3 are selected based on this type, the adjustment pattern 141 may not be printed as expected. Therefore, it may be difficult for the user to pre-select the printing modes Md1 and Md3. In this case, a predetermined test pattern is printed before printing the adjustment pattern 141, and this makes it possible to easily evaluate which of the printing modes Md1 and Md3 should be selected.

[0177] Figure 21 The flowchart showing the acquisition process according to the third embodiment is shown. Except for S2201 and S2202, the steps illustrated here are the same as those in the second embodiment above (see Figure 20 ), and the description thereof will be omitted.

[0178] In S2201, the CPU 102 prints Figure 6A and Figure 6BThe sub-patterns 61 and 62 shown are used as test patterns.

[0179] In S2202, the CPU 102 detects the optical characteristics of the printed test pattern (see Figure 8 and Figure 9 ), and determines whether the change in the reflection intensity between the regions Sr1 and Sr2 can be specified based on the test pattern printed in the printing mode Md1. This determination is made according to the same process as in S2102, that is, based on whether the change rate of the reflection intensity meets the standard. Note that this step is implemented by the detection of the optical sensor 200, but it can be performed by the visual observation of the user.

[0180] If the change in the reflection intensity between the regions Sr1 and Sr2 can be specified, the process proceeds to S2101, otherwise the process proceeds to S2106.

[0181] That is, according to this embodiment, based on the pre-printed test pattern, it is specified whether the adjustment pattern 141 should be printed in the printing mode Md1 or in the printing mode Md3. The printing mode Md1 or the printing mode Md3 is selected based on the specified result. Even if the type of the printing medium P is specified in advance, the adjustment pattern 141 may not be printed as expected. Therefore, according to this embodiment, the adjustment pattern 141 can be appropriately printed even in such a case.

[0182] According to this embodiment, since the adjustment pattern 141 is printed in the printing mode Md1 or the printing mode Md3 corresponding to the type of the printing medium P, the adjustment pattern 141 is not printed in a non-corresponding printing mode unnecessarily. Therefore, according to this embodiment, the same effects as those in the above-described first embodiment and second embodiment can be obtained, and additionally, it is beneficial to avoid unnecessary consumption of the reaction liquid.

[0183] In this embodiment, the ejection port array 33RCT capable of ejecting the reaction liquid is arranged on the downstream side of the ejection port array capable of ejecting the color ink (for example, the ejection port array 33K) in the forward path of the print head 24. If the printing medium P is, for example, a non-absorbent (or almost non-absorbent) printing medium and is of a type in which the ink is easily wetted and spread (for example, synthetic paper), then in Figure 16 and Figure 17The adjustment pattern 141 is formed in one of the printing patterns Md2 and Md3 shown. That is, for the forward path and the reverse path of the print head 24, the adjustment pattern 121 and the adjustment pattern 122 obtained by overlapping the adjustment pattern of the reaction liquid and the adjustment pattern of the color ink are formed. Here, when the adjustment pattern 122 is formed in the reverse path, in the previous forward path, the pattern 1213 (sub-pattern 137) is further formed as an underlying pattern through the ejection port array 33RCT. In the case where the underlying pattern is pre-formed, the flow of the droplets of the color ink in the adjustment pattern 125 (pattern 1211) can be prevented. Thereafter, the position shift of the reaction liquid can be appropriately visualized by the adjustment pattern 126 of the reaction liquid formed further thereafter.

[0184] On the other hand, if the print medium P is, for example, a non-absorbent (or almost non-absorbent) print medium and is of a type in which the ink hardly wets and spreads (e.g., a glossy vinyl chloride film), then the adjustment pattern 141 is formed in the Figure 14 printing pattern Md1 shown. That is, in the forward path, the adjustment pattern 124 (pattern 1212) of the reaction liquid and the adjustment pattern 123 (pattern 1211) of the color ink are formed in an overlapping state to form the adjustment pattern 121. On the other hand, in the reverse path, the adjustment pattern 126 (pattern 1212) of the reaction liquid that is part of the adjustment pattern 122 is formed, and in the subsequent forward path, the adjustment pattern 125 (pattern 1211) of the color ink that is the other part of the adjustment pattern 122 is formed.

[0185] According to the formation method of the adjustment pattern 141, the position shift of the discharge of the reaction liquid between the forward path and the reverse path can be evaluated, and the driving timing of the ejection port array 33RCT can be appropriately corrected.

[0186] In this embodiment, the moving direction of the print head 24 in which the ejection port array 33RCT is located on the downstream side with respect to other ejection port arrays 33 (e.g., the ejection port array 33K) capable of discharging color ink is defined as the forward path, and the opposite direction is defined as the reverse path. However, the forward path and the reverse path can be interchanged. Some of the adjustment patterns are each formed by a plurality of sub-patterns. However, each sub-pattern can be represented as an adjustment pattern, and various types of patterns can be represented by equivalent other names.

[0187] <Program>

[0188] Embodiments of the present invention can also be implemented by the following method, that is, software (including a computer program product of computer programs / instructions) that executes the functions of the above embodiments is provided to a system or device via a network or various storage media, and a computer (central processing unit (CPU), microprocessing unit (MPU)) of the system or device reads and executes the computer programs / instructions.

[0189] <Other>

[0190] In the above description, as an example, the printing device 10 using the inkjet printing method is described. However, the printing method is not limited to the above mode. The printing device 10 may be a single-function printer having only a printing function, or may be a multi-function printer having multiple functions such as a printing function, a FAX function, and a scanner function. In addition, for example, the printing device may be a manufacturing device configured to manufacture a color filter, an electronic device, an optical device, or a microstructure, etc. by a predetermined printing method.

[0191] In addition, "printing" in this specification should be interpreted in a broader sense. Therefore, regardless of whether the object formed on the printing medium is meaningful information such as characters or graphic patterns, and also regardless of whether the information can be visually perceived by humans, the "printing" mode can be used.

[0192] Like "printing", "printing medium" should also be interpreted in a broader sense. Therefore, the concept of "printing medium" can include not only generally used paper, but also any member capable of receiving ink, which includes fabrics, plastic films, metal plates, glass, ceramics, resins, wood, and leather materials.

[0193] In addition, in the embodiments, each element is named using an expression based on its main function. However, each function described in the embodiments may be a secondary function and is not strictly limited to the expression. The expression can be replaced with a similar expression. Similarly, the expression "unit or part" can be replaced with "tool", "component", "member", "structure", or "assembly", etc. Alternatively, these can be omitted or added. The expressions "first", "second", etc. in the description of the embodiments are added to distinguish elements and do not indicate priority or importance.

[0194] In addition, two or more than two elements optionally illustrated in the embodiments are not strictly limited to the illustration and can be arbitrarily combined. For example, each of the two or more than two illustrated elements can be additionally selected or alternatively selected. As an example, when arbitrarily combining two elements A and B, the expression "A and / or B" or the expression "at least one of A and B" can be used to indicate one of "only A", "only B", and "both A and B".

[0195] While the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A printing device, characterized in that, Comprising: A print head, which includes a first nozzle array and a second nozzle array; And A print control component, configured to perform printing on a print medium by driving the print head while reciprocating the print head as a serial head, Wherein, the first nozzle array is configured to discharge color ink, The second nozzle array is configured to discharge a reaction liquid, the reaction liquid reacts with the color ink and fixes the color ink on the print medium, and In the case where the moving direction of the print head with the second nozzle array located on the downstream side relative to the first nozzle array is defined as the forward path and the opposite direction is defined as the reverse path, The print control component executes a first drive control for driving the print head such that: For each of the forward path and the reverse path of the print head, an adjustment pattern is formed, the adjustment pattern is configured to adjust the discharge position, and the adjustment pattern is formed by overlapping the pattern of the reaction liquid and the pattern of the color ink, and When forming the adjustment pattern in the reverse path of the print head, in the previous forward path, a base pattern is further formed by the second nozzle array.

2. The printing device according to claim 1, wherein The print control component is further capable of executing a second drive control for driving the print head such that: In the forward path of the print head, the adjustment pattern is formed, and In the reverse path of the print head, the pattern of the reaction liquid that is part of the adjustment pattern is formed, and in the next forward path, the pattern of the color ink that is the other part of the adjustment pattern is formed.

3. The printing device according to claim 2, characterized in that, It further includes a specifying component for specifying the type of the print medium, Wherein, the print control component selectively performs the first drive control and the second drive control based on the specifying result of the specifying component.

4. The printing device according to claim 3, wherein The print control component drives the print head to form at least two test patterns for evaluating which of the first drive control and the second drive control should be used to form the adjustment pattern, and The specifying component makes the specification based on the at least two test patterns.

5. The printing device according to claim 1, wherein In the adjustment pattern, The pattern of the color ink is a uniform pattern, and The pattern of the reaction liquid is a pattern formed by alternately forming at least two patterns with different dot densities.

6. The printing device according to claim 5, wherein The base pattern is another uniform pattern different from the uniform pattern of the color ink.

7. The printing device according to claim 5, wherein The adjustment pattern is one of a plurality of adjustment patterns, and Between the plurality of adjustment patterns, the positions of the at least two patterns formed alternately are different from each other in the reciprocating movement direction of the print head.

8. The printing device according to claim 1, wherein, It further includes a reading component for reading the adjustment pattern, Among them, the printing control component corrects the driving timing of the second nozzle array based on the reading result of the reading component.

9. The printing device according to claim 1, wherein when the area through which the first nozzle array and the second nozzle array pass by the reciprocating movement of the print head is divided into a first area and a second area in a direction crossing the direction of the reciprocating movement, the printing control component performs the first driving control such that: for the first area, the adjustment pattern is formed in the forward path of the print head, and for the second area, the adjustment pattern is formed in the reverse path of the print head.

10. A control method for a printing device, the printing device comprising: A print head comprising a first nozzle array and a second nozzle array; and a printing control component for performing printing on a print medium by driving the print head while reciprocating the print head as a serial head, wherein the first nozzle array is configured to discharge color ink, the second nozzle array is configured to discharge a reaction liquid that reacts with the color ink and fixes the color ink on the print medium, and when the moving direction of the print head with the second nozzle array located on the downstream side relative to the first nozzle array is defined as the forward path and the opposite direction is defined as the reverse path, the control method includes: for each of the forward path and the reverse path of the print head, an adjustment pattern is formed, the adjustment pattern is configured to adjust the discharge position, and the adjustment pattern is formed by overlapping the pattern of the reaction liquid and the pattern of the color ink; and when the adjustment pattern is formed in the reverse path of the print head, in the previous forward path, a base layer pattern is further formed through the second nozzle array.

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