Recording apparatus and ejection method

Abstract

To suppress deposition of ink in an ink receiver.SOLUTION: When a preliminary discharge receiver has a slope and a recording device performs a preliminary discharge operation while a carriage performs scanning in a direction ascending the slope, the recording device relocates an impact position of a deposition suppression ink to the downstream of the slope while partially overlaying the impact position on the impact position of ink that is likely to deposit.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a recording apparatus and a discharge method. [Background technology]

[0002] Some inkjet recording devices perform a preliminary ejection operation in which ink in the ejection ports of a recording head is ejected to a location other than the recording medium to prevent ink from becoming viscous and becoming unable to be ejected. Patent Document 1 discloses that a groove with a difference in height in the carriage scanning direction is provided on the platen as an ink receiving portion that receives the preliminary ejected ink. It also discloses that the ink that lands on the inclined portion of the ink receiving portion flows to the lower side of the inclination and is ejected from above the platen. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-73581 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even with an inclined ink receiving section as in the prior art document, depending on the properties of the ink used and the temperature and humidity environment in which the recording device is placed, the ink may not flow down the inclined section but may remain there, thickening and causing the ink to accumulate. If the deposits become too high, there is a risk that the recording medium will come into contact with the deposits when it passes over the ink receiving section, becoming soiled, or that the deposits will adhere to the carriage when it passes over.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to suppress the accumulation of ink in the ink receiving portion. [Means for solving the problem]

[0006] The present invention provides a recording means capable of ejecting a plurality of types of ink including a first ink that causes ink deposition when ejected onto a discharge receiving portion, and a second ink that suppresses deposition of the first ink; a moving means capable of moving the recording means in a predetermined direction; a discharge receiving portion on which ink that is not used in recording an image ejected from the recording means lands; and a control means for controlling the timing of ejection of ink from the recording means, wherein the discharge receiving portion is inclined so that the positions at which ink lands are lower on one side than on the other side in the predetermined direction, and the control means controls the landing positions of the first ink ejected onto the discharge receiving portion when the recording means ejects ink while moving from a lower position to a higher position on the inclination of the discharge receiving portion by the moving means. The landing position of the first ink that is ejected first The landing position of the second ink is at least Also heavy The landing position of the first ink is shifted to a position where the inclination of the ejection receiving portion is higher than that of the second ink. The lower end of the landing position of the second ink is landed at a position on the discharge receiving portion that is lower in slope than the lower end of the landing position of the first ink. The ejection timing is controlled so that the ink droplets are ejected in a uniform manner. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress the accumulation of ink in the ink receiving portion. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an external view of an inkjet recording apparatus according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the periphery of a carriage and a platen according to the first embodiment. [Figure 3] FIG. 1 is a schematic top view of the inside of an inkjet recording apparatus according to a first embodiment. [Figure 4] FIG. 2 is a diagram illustrating the arrangement of ejection openings in a print head according to the first embodiment. [Figure 5] FIG. 3 is a cross-sectional view of a preliminary ejection receiving portion in the first embodiment. [Figure 6] 10 is a table showing the number of preliminary ejections during a printing operation in the first embodiment. [Figure 7] FIG. 3 is a cross-sectional view of a preliminary ejection receiving portion in the first embodiment. [Figure 8] FIG. 1 is a block diagram of an applicable inkjet recording apparatus according to a first embodiment. [Figure 9] 10 shows the results of an experiment to determine the ease of deposition of each ink in the first embodiment. [Figure 10] 10 shows the results of an experiment to determine the amount of ink required to suppress deposition of each ink according to the first embodiment. [Figure 11] 5A and 5B are diagrams showing the relationship between the preliminary ejection start positions and the landing positions of deposition-reducing ink and ink that is prone to deposition in the first embodiment. [Figure 12] 10A and 10B are diagrams showing the relationship between the preliminary ejection start positions and the landing positions of deposition-inhibiting ink and ink that is prone to deposition in the second embodiment. [Figure 13] 10 is a table showing the number of preliminary ejections during a printing operation in the third embodiment. [Figure 14] 10A and 10B are diagrams showing the relationship between the preliminary ejection start position and the landing position of deposition-preventing ink and deposition-prone ink, which are ejected in different numbers, according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, components having the same functions are given the same reference numerals in the drawings, and their description may be omitted.

[0010] The term "recording" as used in this specification refers not only to the formation of meaningful information such as characters and figures, but also to the formation of images, patterns, etc. on a recording medium, or the processing of a medium, regardless of whether the information is visible to humans or not.

[0011] Furthermore, the term "recording medium" used in this specification does not only refer to paper used in general recording devices, but also broadly includes materials that can accept ink, such as vinyl, cloth, plastic film, metal plates, glass, ceramics, wood, leather, etc. Furthermore, the term "ink" used in this specification should be interpreted broadly, and refers to a liquid that can be applied to a recording medium to form an image, design, pattern, etc., or to process the recording medium, or to process the ink.

[0012] (First embodiment) (Inkjet recording device) FIG. 1 is an external view of an inkjet recording apparatus (hereinafter simply referred to as a recording apparatus) 100 to which the present invention can be applied. The inkjet recording apparatus 100 of this embodiment is configured to be capable of recording on roll-shaped recording media ranging in size from 10 inches to 60 inches. Note that the size of the recording media is not limited to this, and cut recording media may be used instead of rolls. In FIG. 1, reference numeral 101 denotes a stand on which the recording apparatus main body 100 is placed, and reference numeral 102 denotes a stacker on which ejected recording media are stacked. The recording apparatus 100 is provided with a display panel 103 for displaying various recording information and setting results, and an operation unit 104 for setting the recording mode, recording media, etc. It also has an openable upper cover 106. Furthermore, ink tank supply units 105 for accommodating ink tanks and supplying ink to the print head are located on both sides of the recording apparatus 100.

[0013] FIG. 2 is a cross-sectional view of the inkjet recording apparatus 100, showing the carriage 201, which functions as a moving device for moving the print head, and the suction-type platen 207 (support member), which sucks air and supports the print medium by suction. FIG. 3 is a schematic top view of the interior of the inkjet recording apparatus, with FIG. 3(a) showing the state before the print medium 205 is transported, and FIG. 3(b) showing the state after the print medium 205 is transported on the platen. The carriage 201 is equipped with a print head 200 capable of ejecting multiple types of ink and an optical detection sensor 202 that can detect the edge position of the print medium 205. The print head 200 has a plurality of nozzle arrays for ejecting ink, one for each type of ink. Ink is supplied to the print head 200 from an ink tank 1 through a tube. The carriage 201 is supported by a shaft 206 and driven by a carriage motor (not shown) via a carriage belt (not shown), so that it scans back and forth in a direction (X direction, a predetermined direction) that intersects the print medium transport direction (Y direction). Such position information of the carriage 201 is confirmed by reading the scale of the encoder scale 204 with an encoder sensor 203. Furthermore, the recording medium 205 is supported by a platen 207 during recording operation to maintain a constant distance between the recording surface of the recording medium 205 and the recording head. The platen 207 is provided in a position facing the recording head 200 over the entire scanning area of ​​the recording head 200. Furthermore, the recording medium 205 is transported in the transport direction (Y direction) by a pair of transport rollers (not shown) and a pair of paper discharge rollers consisting of a nip roller 400 and a paper discharge roller 401. An image is formed on the recording medium 205 by repeating such transport operation of the recording medium 205 in the transport direction and the reciprocating scanning of the carriage 201.

[0014] The platen 207 is provided with multiple suction ports 208, a borderless printing ink receiving section 209, and a preliminary ejection ink receiving section (hereinafter referred to as the "preliminary ejection receiving section") 210. The areas of the printing ink receiving section 209 and the preliminary ejection ink receiving section 210 where the ejected ink lands are inclined such that one side is higher and the other is lower in the X direction. In this embodiment, all of the preliminary ejection ink receiving sections are inclined such that the positive X direction side is higher. The bottom of the inclination is open, and ink that flows down to the bottom of the inclination is discharged from above the platen to a suction duct 212. The borderless printing ink receiving section 209 and the preliminary ejection ink receiving section 210 are connected to each other and are provided so that air can be sucked in by a common suction fan 211 via the suction duct 212. The suction port 208 is provided at a position where the recording medium is transported, and the suction fan 211 sucks air through the suction port 208 to generate negative pressure, thereby adsorbing the recording medium 205. By performing the recording operation while the recording medium 205 is being adsorbed in this manner, it is possible to prevent the recording medium from floating, and to perform a stable recording operation.

[0015] (recording head) 4 is a view of the print head 200 as seen from the print medium 205 and platen 207 side. The print head has a plurality of ejection ports 220 arranged in a row in the transport direction (Y direction) of the print medium 205. Ports a to f of 220 can be set to different ink types, and in this embodiment, they are ejection ports for the following inks: 220a: Cyan ink 220b: Magenta ink 220c: Yellow ink 220d: Photo black ink 220e: Matte black ink 220f: Gray ink

[0016] (Preliminary ejection during printing operation) The inkjet recording apparatus 100 periodically performs a preliminary ejection operation to discharge ink not used in image recording from the ejection ports in order to remove ink that has thickened due to evaporation of water from the ejection ports and air bubbles inside the ejection ports and to restore the state of the ejection ports. The preliminary ejection receiving unit 210 is used to receive the ink discharged in this preliminary ejection operation. A plurality of preliminary ejection receiving units 210 are provided on the platen 207 in the X direction, and the preliminary ejection receiving unit 210 to be used is selected depending on the size of the recording medium 205. The preliminary ejection receiving unit 210 that is outside the recording medium 205 and closest to the recording medium 205 is selected as the preliminary ejection receiving unit 210 to perform the preliminary ejection. This shortens the scanning distance of the carriage 201, thereby shortening the time required for the recording operation. For example, (a) and (b) in FIG. 2 are examples in which the lengths of the recording medium 205 in the X direction are different. In the case of FIG. 2(a), it is desirable to use the preliminary ejection receiving portions 210(b) and 210(c), and in the case of FIG. 2(b), it is desirable to use 210(a) and 210(c).

[0017] Furthermore, if preliminary ejection is performed while the carriage is stopped during a printing operation, the printing operation time will be longer, so ejection is performed toward the preliminary ejection receiving portion 210 while the carriage 201 is moving. Figure 5 is a cross-sectional view illustrating the print head 200, the ejection port 220, and the area around the slope on which ink lands in the preliminary ejection receiving portion 210, in order to explain preliminary ejection during a printing operation.

[0018] FIG. 5(a) shows the positions of the print head 200 and the preliminary ejection receiving portion 210 when cyan ink starts to be ejected from the ejection orifices 220a onto the preliminary ejection receiving portion 210 during preliminary ejection while the carriage 201 is moving in the X-positive direction (arrow H) for printing. FIG. 5(b) shows the positions of the print head 200, the cyan ink ejection orifices 220a, and the preliminary ejection receiving portion 210 after the ejection of cyan ink has finished, following the step shown in FIG. 5(a). When preliminary ejection is performed onto the preliminary ejection receiving portion 210 while the carriage 201 is moving in the X-positive direction, the ink lands on the preliminary ejection receiving portion 210 from areas with a low slope (deep grooves) to areas with a high slope (shallow grooves). 230 shows the cyan ink that has landed on the slope of the preliminary ejection receiving portion 210.

[0019] In this embodiment, preliminary ejection during printing operation ejects the number of droplets shown in Figure 6 from each ejection port. There are 1,548 ejection ports per color, and when preliminary ejection is performed, ejection is performed from all of the ejection ports. The weight of one ink droplet from preliminary ejection is 4.5 ng. Furthermore, the ejection interval between preliminary ejections that eject multiple dots with the same ink is 300 dpi in the horizontal direction (X direction), and when 16 droplets are ejected from one nozzle, the horizontal landing width d1 is 1.35 mm.

[0020] Furthermore, the ejection start timing of each ejection port array 220 can be controlled. Figures 5(c) and 5(d) show an example of preliminary ejection of gray ink from the ejection port 220f while the carriage is moving in the positive X direction, where Figure 5(c) shows the ejection start position of the preliminary ejection and Figure 5(d) shows the ejection end position of the preliminary ejection. In this way, the landing position can be controlled by adjusting the ejection start timing of each ejection port array 220. However, the landing position must be within the preliminary ejection receiving portion 210.

[0021] Furthermore, when preliminary ejection is performed on the preliminary ejection receiving section 210 while the carriage is moving in the negative X direction, Figure 7(a) is the start position of the preliminary ejection and Figure 7(b) is the end position of the ejection, and the ink will land in order from the highest point to the lowest point on the slope of the preliminary ejection receiving section 210.

[0022] (borderless printing) The borderless printing ink receiving units 209 are located near both ends of the recording medium as shown in Figure 3(b), and are used to receive ink ejected when performing borderless full-surface printing on the recording medium. Borderless printing is a method of recording over the entire surface of the recording medium 205 by ejecting ink even to a position that extends beyond the recording medium 205. Note that multiple borderless printing ink receiving units 209 can be provided in the X direction so that they can be selected according to the size of the recording medium, and one pair of the multiple borderless printing ink receiving units 209 can be selected for use depending on the size of the recording medium.

[0023] (Block diagram) FIG. 8 is an internal block diagram of the inkjet recording apparatus 100. A personal computer (PC) 300 is connected to the recording apparatus 100 for controlling the apparatus via the image data to be recorded and a printer driver, etc. The recording apparatus 100 includes a control unit 301 for controlling the entire apparatus, various drive unit components, and a carriage 201 carrying the recording head 200. The carriage unit 302 includes a carriage motor for driving the carriage 201 via a carriage belt (not shown), an encoder sensor 203 for reading an encoder scale 204, etc. The recording medium transport unit 303 includes transport rollers for transporting the recording medium 205, a paper discharge roller 401, and a transport motor for driving these rollers. The suction unit 304 includes a platen 207, a suction port 208, a borderless printing ink receiver 209, a preliminary ejection ink receiver 210, a suction fan 211, and a suction duct 212. The power supply unit 306 is connected to an external power source and is used to control the control unit 301 and operate each drive unit. The operation unit 307 is a unit for operating the main body of the recording device 100, and is composed of the display panel 103 and the operation unit 104.

[0024] The control unit 301 is composed of a driver section 308, a sequence control section 309, an image processing section 310, a timing control section 311, and a head control section 312. The sequence control section 309 performs general control such as starting and stopping each functional block, controlling the transport of the recording medium, and controlling the scanning of the carriage. Furthermore, the sequence control section 309 also has the function of controlling the drive voltage (number of rotations) of the suction fan 211 to change the suction force of the suction unit 304.

[0025] The driver unit 308 outputs control signals based on commands from the sequence control unit 309 to each unit, and drives a carriage motor that scans the carriage 201, a conveyance motor that drives conveyance rollers and paper discharge rollers, a suction fan 211, etc. The driver unit 308 also transmits signals from each unit to the sequence control unit 309.

[0026] The image processing unit 310 performs image processing to separate and convert input image data from the host device 300 into print data for colors such as photo black, cyan, magenta, and yellow. The timing control unit 311 functions to transfer the print data converted and generated by the image processing unit 310 to the head control unit in conjunction with the position of the carriage 201 obtained by the encoder sensor 203. The head control unit 312 converts the print data input from the timing control unit 311 into a head control signal and outputs it, and also controls the temperature of the print head 200 based on commands from the sequence control unit 309.

[0027] (Recovery Unit) In FIG. 2, a recovery unit 10 is provided in an area (outside the printing area) outside the printing medium 205 in the movement direction of the carriage 201. The carriage 201 moves to a position facing the recovery unit 10 when initially filling the print head 200 with ink from the ink tank 1 (initial filling) or when recovering the ejection performance of the print head 200 (recovery operation). The recovery unit 10 has a cap 31 that can cover the ejection port surface of the print head 200 and a pump (suction pump) 32 connected to the cap 31 via a tube. When the carriage 201 moves to a position facing the recovery unit 10, the recovery unit 10 raises the cap 31 so that the cap 31 covers the ejection port surface of the print head 200. With the cap 31 covering the ejection port surface of the print head 200, the recovery unit 10 drives the pump 32 to create a negative pressure inside the cap 31 and perform a suction operation to suck ink from the print head 200. The recovery unit 10 also has a wiper (wiper blade) 30 that performs a wiping operation to wipe the ejection port surface of the recording head 200. After the suction operation is completed, the wiper 30 wipes the ejection port surface.

[0028] (Ink accumulation) Next, we will explain the ink accumulation that occurs in the recording apparatus of this embodiment. The recording apparatus of this embodiment forms images using six colors of pigment ink (cyan ink, magenta ink, yellow ink, photo black ink, matte black ink, and gray ink). Ink accumulation refers to a phenomenon in which, when ink is ejected onto the preliminary ejection ink receiving portion 210 of the platen 207, it flows down the slope of the preliminary ejection ink receiving portion 210, is not discharged into the suction duct 212, and remains on the surface of the preliminary ejection ink receiving portion 210. This phenomenon occurs when ink containing a colorant with low solubility or ink whose viscosity increases significantly when water evaporates, reducing its fluidity. The tendency for ink to accumulate is greater when the pigment concentration or solid component concentration in the ink is high, or when the viscosity after water evaporation is high. Ink accumulation can also be determined from the following experiment.

[0029] (Experiment: Determining the ease of ink accumulation) An ink dripping device is installed above the ink receiving unit on the platen, and the target ink is intermittently dripped in a high-temperature, low-humidity environment. Whether or not deposits form on the ink receiving unit 210 after a certain number of drips can determine whether the target ink is prone to deposits. A deposit-forming state refers to a state in which the amount of ink discharged from the ink receiving unit 210 to the suction duct 212 is small compared to the amount of ink dripped, and the amount of ink accumulated at the drip position increases as the number of drips increases, resulting in a higher height of the thickened ink. A deposit-free state refers to a state in which ink adheres to the ink receiving unit 210, but even if new ink is continuously dripped at the previous drip position, the newly added amount of ink flows down from the ink receiving unit 210 to the suction duct 212, resulting in no change in the height of the ink adhering to the drip position.

[0030] Furthermore, the ease with which the target ink deposits can be evaluated based on the number of drops that cause deposits of the target ink.

[0031] Figure 9 shows the results of an experiment evaluating the ease of deposition of each ink. In this experiment, deposition occurred with yellow ink after it was dropped 500 times onto the pre-ejection ink receiving area. Deposition also occurred with photo black ink after it was dropped 50 times, and with matte black ink after it was dropped 100 times. These results show that the inks most likely to deposit are photo black ink > matte black ink > yellow ink. On the other hand, no deposition occurred with cyan ink, magenta ink, or gray ink.

[0032] (Experiment: Determining the amount of ink that prevents accumulation) Next, we investigated the deposition suppression effect of the cyan, magenta, and gray inks, which did not cause deposition in the above experiment. We conducted experiments to determine how much of the cyan, magenta, and gray inks should be mixed with the photo black ink to prevent deposition.

[0033] Figure 10 shows the results of an experiment evaluating the deposition suppression effect of each ink. In this experiment, we investigated whether ink deposition occurred when cyan ink, magenta ink, and gray ink were mixed in amounts of 0.5, 1, and 3, respectively, with 1 amount of photo black ink.

[0034] The results of this experiment showed that to eliminate ink buildup, half the amount of cyan ink or gray ink (1:0.5) relative to the amount of photo black ink, and three times the amount of magenta ink (1:3) were required. Based on these results, in this embodiment, cyan ink, gray ink, and magenta ink are used as buildup suppression inks that dissolve ink deposits and suppress buildup.

[0035] (Preliminary ejection during printing) Next, the preliminary ejection operation during a recording operation according to this embodiment will be described. When the recording device 100 receives a print signal, the recording head 200 performs preliminary ejection onto the cap 31 while the carriage 201 is stopped (pre-recording preliminary ejection operation). Because time may have passed since the previous ink ejection operation, the ink viscosity inside the ejection openings 220 may have increased compared to the preliminary ejection during the recording operation. Therefore, before starting a recording operation on the recording medium 205, a preliminary ejection operation is performed with a greater number of ejections than the preliminary ejection during the recording operation. Next, the recording medium 205 is transported to the state shown in FIG. 3(b), where the recording medium 205 is placed on the platen 207. After that, the carriage 201 moves back and forth in the X direction to record an image corresponding to the width of the ejection openings of the recording head 200 in the Y direction, and then the recording medium 205 is transported in the Y direction. This operation is repeated to perform the recording operation. During this recording operation, when recording is performed while the carriage is moving in the positive X direction, preliminary ejection is performed onto the preliminary ejection receiving portion 210(c) immediately before ejection onto the recording medium 205.

[0036] At this time, the ejection start positions of the deposition-suppressing inks, cyan ink, magenta ink, and gray ink, are shifted by -0.08 mm in the positive X direction (to the right in the figure) from the ejection start positions of the deposition-suppressing inks, yellow ink, photo black ink, and matte black ink, which are inks that tend to accumulate. This causes the deposition-suppressing ink to land on the side of the preliminary ejection receiving section 210 with a lower slope than the inks that tend to accumulate. Figure 11(a) shows the ejection start position of cyan ink, which is the deposition-suppressing ink, and Figure 11(b) shows the ejection start position of yellow ink, which is ink that tends to accumulate. The offset between these start positions is d2 (0.08 mm). 0.08 mm is just an example, and the offset is not limited to this, as long as there is some overlap.

[0037] The preliminary ejection of each ink during printing operation lands over a width of 1.35 mm in the X direction, so the positional relationship of the landed inks is as shown in Figure 11(c). Figure 11(c) is an enlarged view of part C in Figure 11(a). T1 represents the landing position of the deposition-suppressing ink, T2 represents the landing position of the ink that is prone to deposition, the offset in ejection start timing d2, and the landing width in the X direction d1 for each color. (For ease of understanding, Figure 11(c) shows T1 and T2 as having thickness, with T2 being above T1. However, in reality, there is no thickness, and the order of vertical overlap depends on the arrangement of the ejection orifices.) The ejection order can be either the deposition-suppressing ink or the ink that is prone to deposition first. Furthermore, the ink that is ejected last can be either the deposition-suppressing ink or the ink that is prone to deposition.

[0038] Among the landing positions T2 of ink that is prone to accumulation, the ink droplets that are located on the lower side of the slope are the first ink droplets of the preliminary ejection of that color, and therefore there is a high possibility that the time that has passed since the previous ejection has increased the viscosity of the ink that has landed. In this embodiment, the deposition-suppressing ink T1 is ejected so that it overlaps with the downstream portion of T2. Therefore, the deposition-suppressing ink dissolves the ink that is prone to accumulation, making it easier for it to flow downstream of the preliminary ejection receiving portion 210, thereby suppressing the accumulation of ink.

[0039] In this embodiment, all deposition-suppressing inks are ejected at position T1, and all deposition-prone inks are ejected at position T2, but the ejection positions may be shifted for each color as long as the deposition-suppressing ink is ejected so as to overlap the beginning of ejection of the deposition-prone ink. For example, the deposition-suppressing ink, cyan ink, may be ejected at position T1, and the other inks may be ejected at position T2.

[0040] (Second embodiment) In the first embodiment, preliminary ejection to the preliminary ejection receiving unit 210 was performed only when the carriage 201 moved in the positive X direction during printing. If preliminary ejection is required more frequently, preliminary ejection is performed not only when the carriage 201 moved in the positive X direction but also when the carriage 201 moved in the negative X direction. In this embodiment, such a case will be described. The same parts as in the first embodiment will be omitted.

[0041] The timing of the preliminary ejection when moving in the negative X direction is immediately before scanning the recording medium 205, and it is performed onto the preliminary ejection receiving portion 210 located near the recording medium 205. In the case of the size of the recording medium 205 shown in FIG. 2(a), preliminary ejection is performed onto the preliminary ejection receiving portion 210(b), and in the case of the size of the recording medium 205 shown in FIG. 2(b), preliminary ejection is performed onto the preliminary ejection receiving portion 210(a). The case of moving in the positive X direction is the same as in the first embodiment, so a description thereof will be omitted.

[0042] At this time, the ejection start positions of the deposition-suppressing inks, cyan ink, magenta ink, and gray ink, are shifted by +0.08 mm in the positive X direction (to the left in the figure) from the ejection start positions of the deposit-suppressing inks, yellow ink, photo black ink, and matte black ink, which are inks that tend to accumulate. This causes the ejection start position of the deposition-suppressing ink to be on the side of the preliminary ejection receiving section with a steeper slope than the inks that tend to accumulate. Figure 12(a) shows the ejection start position of cyan ink, which is a deposition-suppressing ink, and Figure 12(b) shows the ejection start position of yellow ink, which is an ink that tends to accumulate, with the offset between these start positions being d3 (0.08 mm).

[0043] The preliminary ejection of each ink during printing operation lands in a width of 1.35 mm in the X direction, so the positional relationship of the landed ink is as shown in Figure 12(c). T1 is the landing position of the deposition-inhibiting ink, T2 is the landing position of the ink that is prone to deposition, the offset d3 in the ejection start timing, and d1 is the landing width of each color in the X direction.

[0044] In this case, among the landing positions T2 of ink that is prone to accumulation, the ink droplets that are closer to the slope are the first ink droplets of the preliminary ejection of that color, and therefore there is a high possibility that the time that has passed since the previous ejection has increased the viscosity of the ink that has landed. In this embodiment, the deposition-suppressing ink T1 is ejected at the same position as the upstream portion of T2 so as to sufficiently overlap. Therefore, the deposition-suppressing ink dissolves the ink that is prone to accumulation, making it easier for it to flow downstream of the preliminary ejection receiving portion 210, thereby suppressing the accumulation of ink.

[0045] In this embodiment, all deposition-suppressing inks are ejected at position T1, and all deposition-prone inks are ejected at position T2, but the ejection positions may be shifted for each color as long as the deposition-suppressing ink is ejected so as to overlap the beginning of ejection of the deposition-prone ink. For example, the deposition-suppressing ink, cyan ink, may be ejected at position T1, and the other inks may be ejected at position T2.

[0046] (Third embodiment) In the above-described embodiment, the number of ejections in the preliminary ejection during the printing operation is the same for all colors. In this embodiment, an embodiment in which the number of ejections in the preliminary ejection is changed will be described. The same parts as in the above-described embodiment will be omitted.

[0047] FIG. 13 shows the number of preliminary ejection shots during a printing operation in this embodiment. In this example, only magenta ink is ejected twice as many times as the other colors. Therefore, the landing area of ​​the preliminary ejection in the preliminary ejection receiving section 210 is also twice as long. FIG. 14 shows the positional relationship of ink that has landed in the preliminary ejection receiving section 210 in this embodiment. FIG. 14(a) shows preliminary ejection while the carriage is moving in the positive X direction, and FIG. 14(b) shows preliminary ejection while the carriage is moving in the negative X direction. Control other than the number of preliminary ejection shots is the same as in the first and second embodiments. In FIG. 14, T3 indicates the landing position of magenta ink, and d4 indicates the landing area of ​​magenta ink in the X direction. In this embodiment, the entire area of ​​area T2 where the accumulation ink lands overlaps area T3 where the accumulation-suppressing magenta ink lands. In this way, even if the ejected inks land in different areas, the accumulation suppression effect in the preliminary ejection receiving section is achieved. In this embodiment, the preliminary ejection amount of magenta ink is increased, but other deposition suppression inks may also be increased.Furthermore, the deposition suppression inks for which the preliminary ejection amount is increased may be two or more types.

[0048] In the above-described embodiment, examples of inks containing coloring materials, such as cyan ink, magenta ink, gray ink, yellow ink, photo black ink, and matte black ink, were described, but the present invention can also be applied to print heads that eject other colors. It can also be applied to print heads that eject inks that do not contain coloring materials, such as clear ink. The clear ink is used as deposition-inhibiting ink. [Explanation of symbols]

[0049] 100 Inkjet recording device 200 recording head 201 Carriage 205 Recording Media 207 Platen (supporting member) 209 Borderless printing ink receiver 210 Pre-ejection receiving part 212 Suction duct

Claims

1. a recording means capable of ejecting a plurality of types of ink, including a first ink that causes ink accumulation when ejected onto an ejection receiving portion, and a second ink that suppresses the accumulation of the first ink; a moving means capable of moving the recording means in a predetermined direction; a receiving portion for receiving ink that is not used for recording an image and is discharged from the recording means; a control means for controlling the timing of ink ejection from the recording means; and the ejection receiving portion is inclined so that the position where the ink lands is lower on one side than on the other side in the predetermined direction, The control means controls the ejection timing so that, when the recording means ejects ink while moving from a low position to a high position on the inclination of the ejection receiving portion using the moving means, the landing positions of the first ink ejected onto the ejection receiving portion at least overlap with the landing position of the first ink ejected first and the landing position of the second ink, the landing position of the first ink is shifted to a position with a higher inclination of the ejection receiving portion than the landing position of the second ink, and the lower end of the landing position of the second ink lands at a position with a lower inclination of the ejection receiving portion than the lower end of the landing position of the first ink.

2. The recording device described in claim 1, characterized in that, when the recording means ejects ink while moving from a high position to a low position on the inclination of the ejection receiving portion by the moving means, the control means controls the ejection timing so that, among the landing positions of the first ink ejected to the ejection receiving portion, the landing position of the first ink ejected first and the landing position of the second ink at least overlap, and the landing position of the first ink is shifted to a position on the lower inclination of the ejection receiving portion than the second ink.

3. 3. The recording apparatus according to claim 1, wherein the second ink is ejected onto the ejection receiving portion in an amount greater than that of the first ink.

4. The recording device according to claim 3, characterized in that the control means controls the ejection timing so that the landing position of the second ink in the ejection receiving portion in the predetermined direction is longer than the landing position of the first ink, and so that the landing position of the second ink overlaps the entire area of ​​the landing position of the first ink.

5. 2. The inkjet recording apparatus according to claim 1, wherein the first ink includes at least one of black ink and yellow ink.

6. 6. The recording apparatus according to claim 5, wherein the first ink includes black ink and yellow ink.

7. 2. The recording apparatus according to claim 1, wherein the second ink includes at least one of cyan ink, magenta ink, and gray ink.

8. 8. The recording apparatus according to claim 7, wherein the second ink includes cyan ink, magenta ink, and gray ink.

9. 2. A recording apparatus according to claim 1, wherein the second ink does not contain a coloring material.

10. a recording means capable of ejecting a plurality of types of ink, including a first ink that causes ink accumulation when ejected onto an ejection receiving portion, and a second ink that suppresses the accumulation of the first ink; a moving means capable of moving the recording means in a predetermined direction; a receiving portion for receiving ink that is not used for recording an image and is discharged from the recording means; and a method for ejecting ink from the recording device, the ejection receiving portion being inclined so that the position where the ink lands is lower on one side than on the other side in the predetermined direction, An ejection method characterized by controlling the ejection timing so that, when the recording means ejects ink while moving from a low position to a high position on the inclination of the ejection receiving portion by the moving means, the landing positions of the first ink ejected first to the ejection receiving portion at least overlap with the landing positions of the second ink, the landing position of the first ink ejected at the ejection receiving portion is shifted to a position with a higher inclination of the ejection receiving portion than the landing position of the second ink, and the low end of the landing position of the second ink lands at a lower position on the ejection receiving portion than the low end of the landing position of the first ink.

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