An inkjet printer

Abstract

The present invention relates to the field of inkjet printing technology, and provides an inkjet printer comprising: a paper motion control unit, an ink tank, a print head, and a control unit; the print head comprising an ignition mechanism and M inkjet channels; the M inkjet channels being arranged along the direction of paper motion, with the length of the inkjet channels being perpendicular to the direction of paper motion; the control unit instructing the print head to simultaneously ignite the nozzles of the M inkjet channels at first designated intervals, with the distance between each two adjacent inkjet channels being M×N times the unit dot pitch, for a total of N ignitions, with the distance between two adjacent ignitions of each inkjet channel along the direction of paper motion being M times the unit dot pitch, and the N ignitions constituting a group; a second designated time is paused between each group of ignitions, and multiple groups of ignitions are repeated until printing is completed; the ratio of the second designated time to the first designated time being M-1:M. This solution can effectively increase printing speed and prevent the appearance of a white line that affects printing quality.

Description

Technical Field

[0001] The present invention relates to the technical field of inkjet printing, in particular to an inkjet printer. Background Art

[0002] Printing is a very old technology, but it is constantly being updated. With the continuous development of printing technology, inkjet-based digital printing systems have become widely popular and widely recognized. Many types of digital printing equipment are used for various printing tasks. They are distinguished by the different printheads used, which in turn have different performance parameters and quality indicators.

[0003] Single-pass printing is to arrange the nozzles in a row and keep them stationary. The paper moves quickly under the nozzles. Each nozzle of the nozzle sprays ink droplets at a fixed frequency. These ink droplets form a line on the paper. Many nozzles arranged in a row will form many such parallel lines on the paper. These dense lines form a square. Figure 1 As shown, the printed pattern is formed by areas of the square containing ink and areas without ink. Obviously, to maintain the same density across a line of ink, the higher the inkjet frequency, the faster the paper will move. Printing speed is determined by the firing frequency—the frequency at which the printhead ejects ink. The higher the firing frequency, the faster the printing speed. However, printheads with a high firing frequency are often more expensive and difficult to maintain.

[0004] The existing technical solution is to arrange a row of nozzles in parallel, and each nozzle controls the ignition time independently, so as to spray out a complete pattern, such as Figure 2 As shown. The printing speed of the existing technology is completely dependent on the ignition frequency, and there is little room for improvement in the ignition frequency. In addition, if a nozzle is blocked, a white line will appear, such as Figure 3 As shown, the printing effect is destroyed and the probability of nozzle clogging is very high.

[0005] Therefore, it is necessary to provide an inkjet printer that can effectively improve the printing speed and prevent the appearance of a white line that affects the printing effect.

[0006] The above information disclosed in this Background section is only for enhancement of understanding of the background of the application and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0007] The main purpose of the present invention is to overcome the problem of low printing efficiency of inkjet printers and provide an inkjet printer that can effectively improve the printing speed and prevent the appearance of a white line that affects the printing effect.

[0008] To achieve the above-mentioned purpose, the present invention provides an inkjet printer in a first aspect, comprising: a paper motion control unit, an ink tank, a print head and a control unit.

[0009] The paper motion control unit is used to control the uniform motion of the paper;

[0010] The ink tank is connected to the print head and is used to provide ink;

[0011] The print head includes an ignition mechanism and M inkjet channels, each inkjet channel including two or more rows of nozzles offset from each other; the ignition mechanism is connected to the nozzles of the inkjet channels to control ink dripping from the nozzles; the M inkjet channels are arranged along the moving direction of the paper, with the length direction of the inkjet channels being perpendicular to the moving direction of the paper, where M is a natural number greater than or equal to 2; and N is a natural number greater than or equal to 2.

[0012] The control unit is communicatively connected to the print head and is used to control the print head to ignite and drip ink droplets onto the paper; the control unit instructs the print head to ignite the nozzles of M inkjet channels at the same time every first specified time, and each time one nozzle is ignited, at most one ink droplet is dripped, and the distance between each two adjacent inkjet channels is M×N times the unit dot pitch, and the print head is ignited N times in total. The distance between the ink droplets dripped from two adjacent ignitions of each inkjet channel along the movement direction of the paper is M times the unit dot pitch, and N ignitions constitute a group; a second specified time is paused between each group of ignitions, and multiple groups of ignitions are repeated until printing is completed; the ratio of the second specified time to the first specified time is M-1:M.

[0013] As an exemplary embodiment of the present invention, the resolution of the printed product along the moving direction of the paper is N times of 12.5 dpi.

[0014] As an exemplary embodiment of the present invention, when the resolution of the printed product along the moving direction of the paper is 600 dpi and M is 4, the moving speed of the paper is 130-162 m / min.

[0015] Preferably, when the resolution of the printed product along the direction of paper movement is 600 dpi and M is 4, the maximum speed of the paper movement is 160 m / min at an ignition frequency of 21 KHz.

[0016] As an exemplary embodiment of the present invention, the unit dot pitch is the distance between two adjacent pixels of a printed product.

[0017] As an exemplary embodiment of the present invention, each ink droplet corresponds to a pixel.

[0018] As an exemplary embodiment of the present invention, the distance between two adjacent inkjet channels is 180-200 pixels.

[0019] As an exemplary embodiment of the present invention, the number of nozzles in each column is greater than or equal to 400.

[0020] As an exemplary embodiment of the present invention, the distance between two adjacent rows of nozzles is 20-30 pixels.

[0021] As an exemplary embodiment of the present invention, the width of the paper is 700-900 mm, and the length of the inkjet channel is consistent with the width of the paper.

[0022] As an exemplary embodiment of the present invention, the interval between two adjacent nozzles in each nozzle column is K-1 pixels, where K is the number of nozzle columns per inkjet channel, and K is a natural number greater than or equal to 2.

[0023] Preferably, there are four inkjet channels, each inkjet channel has two nozzle columns, the distance between two adjacent inkjet channels is 8.128 mm, and the distance between two adjacent nozzle columns is 1.016 mm.

[0024] As an exemplary embodiment of the present invention, the print head further includes M ink channels, which connect the ink tank and the inkjet channel; each ink channel is connected to K rows of mutually staggered nozzles.

[0025] As an exemplary embodiment of the present invention, each column of nozzles connected to each ink channel is located in a different inkjet channel.

[0026] As an exemplary embodiment of the present invention, the ink color of each inkjet channel is consistent.

[0027] As an exemplary embodiment of the present invention, the control unit controls the print head to repeat M groups of firing N times.

[0028] The advantageous effect of the present invention is that this scheme sets M inkjet channels, each group is ignited N times, after one group is sprayed, the step length between the two groups is adjusted, and then ignited again, so that M groups are ignited to spray the entire printing screen, the movement speed of the paper is accelerated, and the low-frequency ignition frequency is used to output the high-frequency effect, thereby reducing the cost of the nozzle, reducing the defects caused by nozzle blockage, and increasing the printing speed by M-1 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other objects, features, and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings. The drawings described below are merely some embodiments of the present application, and it is apparent to those skilled in the art that other drawings can be derived from these drawings without inventive effort.

[0030] Figure 1 The schematic diagram shows the printing effect of a single pass.

[0031] Figure 2The diagram schematically shows the printing effect of a row of nozzles arranged side by side.

[0032] Figure 3 The diagram schematically shows the printing effect of a row of nozzles arranged in parallel with blocked nozzle holes.

[0033] Figure 4 The figure shows a schematic diagram of M rows of nozzles of a print head.

[0034] Figure 5 The structure of the print head is schematically shown (without the ink channels).

[0035] Figure 6 The structure of the print head (including ink channels) is shown schematically.

[0036] Figure 7 The diagram schematically shows the steps of a rapid printing method of an inkjet printer.

[0037] Figure 8 The schematic diagram of multi-color nozzle printing is shown schematically.

[0038] Figure 9 The schematic diagram of rapid printing of an inkjet printer is shown schematically.

[0039] Figure 10 The comparison diagram of inkjet effect is shown schematically. DETAILED DESCRIPTION

[0040] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the drawings represent like or similar parts, and thus repetitive description thereof will be omitted.

[0041] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0042] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0043] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0044] It should be understood that although the terms first, second, third, etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another. Thus, the first component discussed below could be referred to as the second component without departing from the teachings of the present invention. As used herein, the term "and / or" includes any one and all combinations of one or more of the associated listed items.

[0045] Those skilled in the art will understand that the drawings are merely schematic diagrams of example embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing the present application, and therefore cannot be used to limit the scope of protection of the present application.

[0046] According to a first embodiment of the present invention, the present invention provides a fast printing device, including a paper motion control unit, an ink tank, a print head and a control unit.

[0047] The paper motion control unit is used to control the uniform motion of the paper along its length. The speed of the paper motion is M-1 times the speed of the paper motion using a single inkjet channel, where M is the number of inkjet channels.

[0048] The resolution of the printed product along the paper's moving direction is N times 12.5 dpi, where N is a natural number greater than or equal to 2. When the resolution of the printed product along the paper's moving direction is 600 dpi and M is 4, the paper's moving speed is 130-162 m / min. Preferably, when the resolution of the printed product along the paper's moving direction is 600 dpi and M is 4, and the firing frequency is 21 kHz, the paper's moving speed is a maximum of 160 m / min.

[0049] The ink tank is connected to the print head for supplying ink.

[0050] The printhead includes an ignition mechanism and M inkjet channels. Each inkjet channel includes two or more offset nozzle columns. The ignition mechanism is connected to the nozzles of the inkjet channels to control the ink droplets from the nozzles. The M inkjet channels are arranged along the direction of paper movement, with the length of the inkjet channels perpendicular to the direction of paper movement. M is a natural number greater than or equal to 2; N is a natural number greater than or equal to 2. The printhead also includes M ink channels, which connect the ink tank and the inkjet channels. Each ink channel is connected to K columns of offset nozzles, where K is the number of nozzle columns in each inkjet channel. Each column of nozzles connected to each ink channel is located in a different inkjet channel. The ink color of each inkjet channel is consistent.

[0051] The control unit is communicatively connected to the print head and is configured to control the print head's firing and the dropping of ink droplets onto paper. The control unit instructs the print head to simultaneously fire the nozzles of M inkjet channels at first designated intervals, with each nozzle firing to drop at most one ink droplet. The distance between each two adjacent inkjet channels is M x N times the unit dot pitch, resulting in N firings in total. The distance between two adjacent firings of each inkjet channel along the direction of paper movement is M times the unit dot pitch, and N firings constitute a group. A second designated time is paused between each group of firings, and multiple groups of firings are repeated until printing is complete. The ratio of the second designated time to the first designated time is M-1:M. As a preferred embodiment, the control unit controls the print head to repeat M groups of firings N times.

[0052] The unit dot pitch is the distance between two adjacent pixels in the printed product. Each ink drop corresponds to one pixel.

[0053] In a preferred embodiment, the spacing between two adjacent inkjet channels is 180-200 pixels, preferably 192 pixels, and the number of nozzles in each column is greater than or equal to 400, preferably 400. The spacing between two adjacent columns of nozzles is 20-30 pixels, preferably 24 pixels. The width of the paper is 700-900 mm, and the length of the inkjet channel is consistent with the width of the paper.

[0054] Two or more staggered nozzle rows can improve the resolution along the length of the inkjet channel. Adjacent nozzles in each row are spaced K-1 pixels apart, where K is the number of nozzle rows per inkjet channel and is a natural number greater than or equal to 2. Preferably, there are four inkjet channels, each with two nozzle rows. The spacing between adjacent inkjet channels is 8.128 mm, and the spacing between adjacent nozzle rows is 1.016 mm.

[0055] Specifically, if Figure 4 、 Figure 5 and Figure 6As shown, M inkjet channels are at the bottom of the print head, used to spray ink onto the paper below the print head. The distance between each two adjacent rows of inkjet channels is a specified distance, which is N×M unit dot pitches. The unit dot pitch is the distance between two pixel points of the printed product. The number of nozzles in each inkjet channel is greater than or equal to 800, and the distance between the ink droplets printed by each inkjet channel in the width direction of the paper is one unit dot pitch. Each inkjet channel includes two columns of staggered nozzles, and the number of nozzles in each column is greater than or equal to 400. The two adjacent nozzles in each column of nozzles are 2 unit dot pitches apart. Through the staggered setting, the actual printing effect is the same as that of setting multiple nozzles in each row and each two nozzles are one unit dot pitch apart. It can be considered that the number of nozzles in each row is greater than or equal to 800.

[0056] Figure 4 In the figure, M is 4, the distance between two adjacent inkjet channels is 8.128mm (i.e., the distance between 192 pixels, or 192 / 600 inches), the distance between two adjacent columns of nozzles in each inkjet channel is 1.016mm (i.e., the distance between 24 pixels), the distance between two adjacent nozzles in each column of nozzles is 0.085mm (i.e., the distance between 2 pixels), each column has 400 nozzles, and two adjacent columns of nozzles with the same serial number are 0.042mm apart (i.e., the distance between 1 pixel) in the width direction of the paper. Figure 4 There are 8 rows of nozzles in total, such as Figure 5 As shown in the figure, from right to left they are A column, B column, C column, D column, E column, F column, G column, H column, and the staggered arrangement of two adjacent columns can improve the resolution of inkjet. Figure 6 As shown, there are four ink channels. From right to left, the first connects to columns B and G, the second connects to columns A and H, the third connects to columns C and F, and the fourth connects to columns D and E. The four ink channels have the same color, ensuring the same color for the ink in the M inkjet channels. The ink channels connect non-adjacent columns to eliminate the effects of static electricity.

[0057] The control unit instructs the print head to simultaneously fire the nozzles of M inkjet channels at intervals of a first specified time. Each time a nozzle is fired, a maximum of one ink droplet is dropped. Each ink droplet corresponds to a pixel. No ink droplets are dropped for pixels that do not need to be printed. The interval between each two rows of ink droplets (ink droplets dropped by the same inkjet channel during two adjacent firings) is M-1 pixels, that is, the distance between each two adjacent ink droplets is M times the unit dot pitch. The print head fires N times in total, and each firing constitutes a group. A pause of a second specified time is maintained between each group of firings. Multiple groups of firings are repeated until printing is complete. The ratio of the second specified time to the first specified time is M-1:M.

[0058] The rapid printing device of the first embodiment is used for rapid printing, such as Figure 7 As shown, the following steps are included:

[0059] S1: The paper continues to move along the length of the paper.

[0060] As paper moves through a digital printing press, an encoder on the press changes with the paper's position. The control board uses the encoder's scale to determine the paper's current position and whether ignition is required. Using this method, paper movement can be increased by (M-1) times. Assuming an inkjet resolution of 600 dpi along the paper's direction of motion, a nozzle firing frequency of 21 kHz, and four ink channels, the maximum paper movement speed using traditional point-by-point inkjet printing is 21000 / 600 × 25.4 = 889 mm / s, or a total of 53.3 meters / minute. However, using this method, printing speed can be tripled to 160 meters / minute.

[0061] M inkjet channels are set along the moving direction of the paper, and the interval between two adjacent inkjet channels is M×N times the unit dot pitch, where the unit dot pitch is the distance between two pixel points of the printed product; M is a natural number greater than or equal to 2; N is a natural number greater than or equal to 2.

[0062] The distance between each two adjacent inkjet channels is a specified distance, which is N×M unit dot pitches. Each inkjet channel includes two rows of staggered nozzles, and the number of nozzles in each row is greater than or equal to 400.

[0063] The colors of the inks in the M inkjet channels are consistent.

[0064] Preferably, M is 4, N is 48, and the unit dot pitch is 1 / 600 inch.

[0065] S2: The nozzles of M inkjet channels are ignited simultaneously at every first specified time. Each time a nozzle is ignited, at most one ink droplet is dropped. Each ink droplet corresponds to one pixel point. The distance between the ink droplets dropped after each two ignitions is M times the unit dot pitch. A total of N ignitions are performed.

[0066] No ink drops are applied to pixels that do not need to be printed.

[0067] The number of ignitions is determined by the unit dot pitch and the distance between two adjacent inkjet channels. N is an integer multiple of 2, the resolution in the direction of paper movement is N×12.5 dpi, and the unit dot pitch is 1 / (N×12.5) inches.

[0068] Preferably, since the ink jetting content of the nozzle of the first inkjet channel during the Nth ignition overlaps with that of the subsequent nozzles, in order to reduce repeated ink jetting, the nozzle of the first inkjet channel does not need to drip ink drops during the Nth ignition.

[0069] S3: pause ignition for a second designated time, where the ratio of the second designated time to the first designated time is M-1:M;

[0070] S4: Repeat steps S2 and S3 until printing is completed.

[0071] Repeat steps S2 and S3 M times in total.

[0072] The advantages of the method for rapid printing with an inkjet printer are described below through detailed embodiments.

[0073] Figure 8 The figure shows a schematic diagram of a multi-color print head. A multi-color print head has multiple rows of nozzles arranged side by side. Each row of nozzles is used to spray different colors of ink, usually CMYK four-color ink. Figure 8 From left to right in the middle are the four colors CMYK. As the paper moves, the four-color ink droplets are sprayed at the same position, and the different combinations of inks produce a variety of colors, thus achieving color printing.

[0074] The basic idea of ​​this solution is to have multiple nozzles spray the same color and stagger the ink points so that the ink is not printed on the same position. The four nozzles print different lines respectively, and they complement each other. Different nozzles do not print on the same pixel point to form a complete image. In fact, each inkjet channel mentioned here contains two rows of nozzles that are staggered with each other (such as Figure 4 and Figure 5 As shown), they are close together to improve the lateral resolution. For the sake of ease of description, they are still referred to as a total of 4 inkjet channels.

[0075] like Figure 9 As shown in the figure, for the Epson i3200 printhead, taking 600dpi as an example, the ink drop interval is 1 / 600 inch as the unit dot pitch. The printhead has a total of 4 inkjet channels, such as Figure 4 As shown, the distance between two adjacent inkjet channels is 192 unit dots. First, confirm that M is 4 and N is 48.

[0076] If each nozzle sprays three pixels at a time, the inkjet channel printing resolution will become 150dpi, and the paper moving speed can be increased to three times the original. Each row of nozzles is fired simultaneously. After completing 48 firings, the paper moves 48*4=192 unit dots at the 49th firing. In other words, the position of the paper facing the nozzle hole of the second inkjet channel coincides with the position facing the nozzle hole of the first row at the first firing. As a result, ink is sprayed multiple times at the same position, while the adjacent positions appear blank. Figure 9As shown in the above two schematic diagrams, the paper moves from right to left, and the nozzles of the four inkjet channels are ignited at the same time. After a period of time, the nozzle of the first inkjet channel from the left sprays ink at the same place. The inkjet positions will overlap, and there will be a gap between the two ink droplets.

[0077] To avoid this phenomenon, the method of this solution is: after 48 ignitions at 4 dot spacing (unit dot spacing), the time of the next ignition is advanced by one quarter, that is, 3 dot spacing (unit dot spacing), so that the ink droplets that are supposed to overlap are staggered by one unit dot spacing. Then, 48 ignitions are performed at 4 dot spacing (unit dot spacing), and then ignition is performed once at 3 dot spacing (unit dot spacing), and the cycle continues. Figure 9 As shown, Figure 9 In the third picture, if the nozzle of the second inkjet channel from the left fires at a time interval corresponding to 4 dot pitches after completing 48 ignitions, the ink droplets ejected by the nozzle of the second inkjet channel will overlap with the ink droplets ejected by the nozzle of the first inkjet channel. In order to avoid overlap, there are 3 blank dots between each two adjacent ink droplets. If the nozzle fires at a time interval corresponding to a unit dot pitch, the droplets will move forward to a blank dot to supplement the inkjet image. After igniting 48 times, ignite 48 times in advance by 3 dot pitches. Figure 9 As shown in the fourth figure, the inkjet images are offset and supplemented with each other, and the printing resolution is changed from 150dpi to 600dpi. In other words, every first specified time, 4 rows of nozzles are ignited simultaneously, and each time a nozzle is ignited, a maximum of one ink droplet is dropped. Each ink droplet corresponds to one pixel, and no ink droplets are dropped on pixels that do not need to be printed. There are 3 pixels between each two rows of ink droplets, and a total of N ignition times, N is 48, and N ignitions form a group; pause and ignite for the second specified time, and the ratio of the second specified time to the first specified time is M-1:M; after printing one group, pause for the second specified time before printing the next group, and the interval between each two groups of components is the second specified time, and so on. Since the printing distance is only increased by 3 times at the time of frequency conversion switching (i.e., pause and ignite for the second specified time), the lowest speed in the entire process is used as the final speed, so the paper movement speed will be increased by 3 times than before.

[0078] From the above scheme, we can see that the firing frequency has not changed, but the speed of paper movement has increased. The speed of paper movement has increased to 3 times. This scheme uses a low firing frequency to print a high-frequency ink drop density. If the number of inkjet channels is larger, the paper movement speed will be faster. The paper movement speed is M-1 times that of row-by-row printing. And because the same column of ink dots (ink dots along the direction of paper movement) of this scheme are alternately ejected by four inkjet channels, if one of the nozzles is blocked, it will not block the entire column of ink dots and cause Figure 3Instead of blocking a row of one quarter (1 / M) of ink dots, this will significantly improve the nozzle blocking condition. Figure 10 As shown, Figure 10 The inkjet effect comparison chart shows the complete inkjet pattern on the top, and the inkjet situation after one nozzle is blocked, with only a quarter of the ink dots not coming out.

[0079] The relationship between the inkjet point position and the firing is shown in Table 1. The first row of nozzles corresponds to the nozzles of the first inkjet channel, the second row of nozzles corresponds to the nozzles of the second inkjet channel, the third row of nozzles corresponds to the nozzles of the third inkjet channel, and the fourth row of nozzles corresponds to the nozzles of the fourth inkjet channel.

[0080] Table 1

[0081]

[0082]

[0083]

[0084]

[0085] From the analysis of Table 1, we can conclude that:

[0086] (1) The first group fired 48 times, and the first row of nozzles sprayed from the 3rd dot to the 191st dot every 4 unit dot pitches; the second group fired 48 times, and after one unit dot pitch forward, the first row of nozzles sprayed from the 194th dot to the 382nd dot every 4 unit dot pitches, and the second row of nozzles sprayed from the 2nd dot to the 190th dot every 4 unit dot pitches; the third group fired 48 times, and after one unit dot pitch forward, the first row of nozzles sprayed from the 385th dot to the 573rd dot every 4 unit dot pitches, and the second row of nozzles sprayed from the 193rd dot to the 573rd dot every 4 unit dot pitches. At the 381st dot, the third row of nozzles sprays from the 1st dot to the 189th dot at intervals of 4 dot pitches. The fourth group fires 48 times, and then sprays ink one dot pitch further forward. The first row of nozzles sprays from the 576th dot to the 764th dot at intervals of 4 dot pitches. The second row of nozzles sprays from the 384th dot to the 572nd dot at intervals of 4 dot pitches. The third row of nozzles sprays from the 192nd dot to the 380th dot at intervals of 4 dot pitches. The fourth row of nozzles sprays from the 0th dot to the 188th dot at intervals of 4 dot pitches. ... By supplementing the previous pixel positions with this latter row of nozzles, the paper speed is tripled, while the print resolution remains unchanged.

[0087] (2) The integer multiple of 48 ignition times is the position switching point. As long as the first row of nozzles does not spray during this ignition, all positions will be sprayed once without repeated inkjet, thus the entire image will be sprayed out completely.

[0088] (3) By the same token, if the spacing between two adjacent rows of nozzles is determined to be 8.128 mm, the number of inkjet dots between the two adjacent rows of nozzles at 25 dpi is: 8.128 / 25.4*25=8. The corresponding resolution of the present invention is an integer multiple of 25, and the number of ink droplets between the two rows of nozzles is also an integer multiple of 8. At this time, M is equal to 4, N is equal to 2, and the resolution of the printed product along the direction of paper movement is N times that of 12.5 dpi, that is, a new printing pattern can be rearranged according to this pattern. If the new resolution is a multiple of 25 dpi, for example, 600 dpi is 24 times of 25 dpi, then N=24*2=48. According to the rule of printing M pixels once, every N times, 4×N rows of dots are printed, and the printing position is changed once at intervals, position 4 is changed to position 3, and then 4×N rows of dots are printed according to the above method and position 3 is changed to position 2, and then 4×N rows of dots are printed according to the above method and position 2 is changed to position 1. After the adjustment, the first pixel of the first row of nozzles is not printed, or the last pixel before the adjustment is not printed, and the image will be printed perfectly without any omissions or duplicate dots.

[0089] (4) From the above analysis, it can be seen that the principle of this scheme is to adjust the time interval between each two groups based on the interval between two ink droplets to stagger the ink droplets. As long as the interval between two adjacent inkjet channels is M×N times the unit dot pitch and the distance between the ink droplets dropped by each two ignitions is M times the unit dot pitch, the paper movement speed can be increased to nearly M-1 times while the printing resolution remains unchanged.

[0090] The exemplary embodiments of the present invention are specifically shown and described above. It should be understood that the present invention is not limited to the detailed structure, configuration or implementation described herein; on the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An inkjet printer, characterized in that: include: Paper motion control unit, ink tank, print head and control unit; The paper motion control unit is used to control the uniform motion of the paper; The ink tank is connected to the print head and is used to provide ink; The print head includes an ignition mechanism and M inkjet channels; each inkjet channel includes two or more rows of nozzles offset from each other; the ignition mechanism is connected to the nozzles of the inkjet channels to control the nozzles to drop ink droplets; the M inkjet channels are arranged along the direction of movement of the paper, with the length direction of the inkjet channels being perpendicular to the direction of movement of the paper; M is a natural number greater than or equal to 2; and N is a natural number greater than or equal to 2. The control unit is communicatively connected to the print head and is used to control the print head to ignite and drip ink droplets onto the paper; the control unit instructs the print head to ignite the nozzles of M inkjet channels at the same time every first specified time, and each time one nozzle is ignited, at most one ink droplet is dripped, and the distance between each two adjacent inkjet channels is M×N times the unit dot pitch, and the print head is ignited N times in total. The distance between the ink droplets dripped from two adjacent ignitions of each inkjet channel along the movement direction of the paper is M times the unit dot pitch, and N ignitions constitute a group; a second specified time is paused between each group of ignitions, and multiple groups of ignitions are repeated until printing is completed; the ratio of the second specified time to the first specified time is M-1:M.

2. The inkjet printer according to claim 1, wherein The resolution of the printed product along the direction of paper movement is N times that of 12.5dpi.

3. The inkjet printer according to claim 2, wherein: When the resolution of the printed product along the moving direction of the paper is 600 dpi and M is 4, the moving speed of the paper is 130-162 m / min.

4. The inkjet printer according to claim 1, wherein The unit dot pitch is the distance between two adjacent pixels of the printed product.

5. The inkjet printer according to claim 4, wherein The number of nozzles in each column is greater than or equal to 400; the width of the paper is 700-900 mm, and the length of the inkjet channel is consistent with the width of the paper.

6. The inkjet printer according to claim 1, wherein The interval between two adjacent nozzles in each column of nozzles is K-1 pixels, where K is the number of nozzle columns in each inkjet channel, and K is a natural number greater than or equal to 2.

7. The inkjet printer according to claim 5, wherein: There are 4 inkjet channels, and each inkjet channel has 2 nozzle columns.

8. The inkjet printer according to claim 5, wherein: The print head further comprises M ink channels, which are connected to the ink tank and the inkjet channel; each ink channel is connected to K rows of mutually staggered nozzles.

9. The inkjet printer according to claim 1, wherein The ink color of each inkjet channel is consistent.

10. The inkjet printer according to claim 1, wherein The control unit controls the print head to repeat M groups of firing N times.

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