An automatic adjustment method for multi-nozzle splicing of wide-format inkjet digital printing

Abstract

The present invention relates to the technical field of wide-format inkjet digital printing with multi-nozzle splicing, and particularly to an automatic adjustment method for wide-format inkjet digital printing with multi-nozzle splicing, comprising the following steps: setting the test pattern debugging mode, performing RIP processing on the test pattern, setting the debugging printing mode by the host computer and spraying the test pattern, magnifying the acquisition of the test pattern and calculating the shift discrimination; it can magnify and collect the rasterized image printed by the spliced nozzles after initial adjustment, calculate the nozzle offset by calculating the dot density, and feedback the nozzle offset to the nozzle adjustment micro-motor for adjustment. Through the above process, an information feedback closed loop is formed, thereby automating the complex adjustment process and avoiding the inaccurate situation caused by manual splicing of nozzles.

Description

Technical Field

[0001] The present invention relates to the technical field of wide - format ink - jet digital printing with multi - nozzle splicing, and particularly to an automatic adjustment method for wide - format ink - jet digital printing with multi - nozzle splicing. Background Art

[0002] A wide - format ink - jet digital printer is a device for large - format printing, which is widely used in the fields of advertising, decoration, art, etc. Existing wide - format ink - jet digital printers, such as a new micro - piezoelectric wide - format ink - jet printer disclosed in the patent with the publication number CN201931720U and a digital printing device for the printing manufacturing industry disclosed in the patent with the publication number CN215204071U, can all achieve ink - jet printing work.

[0003] However, it is found in the use process that the structure of the existing wide - format ink - jet digital printer is relatively simple, and nozzle docking is required before use. The traditional nozzle splicing method:

[0004] 1. Calculate the nozzle hole spacing according to the parameters of the nozzles, and design and process a limit plate according to the number of cross - nozzle holes of the nozzles;

[0005] 2. Install the nozzles on the limit plate in a pyramid shape (as Figure 7 shown);

[0006] 3. Set the software to print a test standard pattern, and the test pattern is usually cross - straight lines (as Figure 8 shown);

[0007] 4. Manually fine - tune the position of the nozzles according to the misalignment of the straight lines;

[0008] 5. Repeat step 4 until the test line is printed qualified (as Figure 9 shown).

[0009] The spacing of the nozzles is in the order of micrometers. Therefore, the docking quality has a great influence on the quality of ink - jet printing. By relying on the experience of the debugging personnel to fine - tune the nozzle assembly and repeating the above process until a qualified test picture is printed, the position of the nozzles cannot be automatically adjusted through the feedback of the device. Therefore, the dependence on the debugging personnel is relatively high, and it often takes a long time to successfully debug, and the debugging quality of the device cannot be guaranteed, resulting in poor practicability. Therefore, there is an urgent need for an automatic adjustment method for wide - format ink - jet digital printing with multi - nozzle splicing to improve the above problems. Summary of the Invention

[0010] To solve the above technical problems, the present invention provides a wide - format inkjet digital printing multi - nozzle splicing automatic adjustment method. It can magnify and collect the rasterized image printed by the spliced nozzles after initial adjustment, calculate the offset of the nozzles by calculating the dot density, and feedback the nozzle offset to the nozzle adjustment micro - motor for adjustment. Through the above process, an information feedback closed - loop is formed, thereby automating the complex adjustment process and avoiding the inaccurate situation caused by manual splicing of nozzles.

[0011] A wide - format inkjet digital printing multi - nozzle splicing automatic adjustment method of the present invention includes the following steps:

[0012] S1. Select the test pattern debugging mode setting:

[0013] First, select a test picture in the host computer software, match the corresponding test picture according to the common nozzle models on the market. The corresponding relationship between the test picture and the nozzle mainly considers the printing width and length of different model nozzles, and select the current test channel in the setting of the debugging mode.

[0014] S2. Perform RIP processing on the test pattern:

[0015] The RIP processing is performed on the host computer. When the debugging mode is set, the RIP parameters are automatically set to the monochrome 1 - fold grid parameters.

[0016] S3. The host computer sets the debugging printing mode and prints the test pattern:

[0017] Select the minimum ink droplet in the printing settings, and through the encoder settings, make the printing positions of nozzles not in the same horizontal direction form a dislocation, so as to adjust the acquisition field of view, and the magnified acquisition effective field of view area is located within the scanning boundary, and the scanning boundary is horizontally located within the overlapping printing area of two nozzles.

[0018] S4. Magnify and collect the test pattern:

[0019] The electronic magnifying collector magnifies and collects the test picture, and selects an autofocus - adjustable electronic magnifying collector with a magnification of more than 100 times according to the ink droplet size.

[0020] S5. Shift discrimination calculation:

[0021] Set the encoder offset in the debugging mode. If the printed rectangular monochrome image forms an interleaved layout between nozzles, a halftone image formed by scanning through the electronic magnifying collector is used to represent the interleaved size between nozzles.

[0022] Preferably, in S1, the test channel is selected from the four colors of CMYK.

[0023] Preferably, in S2, the RIP processing algorithm is the same as the traditional RIP processing method.

[0024] Preferably, in S4, during collection, the collection scanning boundary is parallel to the scanning slide rail, and its collection range is the horizontal overlapping part of the ink droplets sprayed by the two nozzles. The enlarged effective field of view D for collection is located within the collection scanning boundary and is continuously collected while moving horizontally along the scanning boundary.

[0025] Preferably, in S5, when the electronic magnifying collector scans, the electronic magnifying collector slides on the scanning slide rail to scan the printed image. The scanning and collection area is the vertical overlapping part of the ink droplets sprayed by the two nozzles, and the scanning result is fed back to the host computer, which discriminates the scanning result.

[0026] Preferably, the steps for the host computer to discriminate the scanning result are as follows:

[0027] S5-1. Identify the inkjet dots in the image collected within the field of view D;

[0028] S5-2. Calculate the number of inkjet dots within the field of view D according to the identification result in S5-1;

[0029] S5-3. Compare the change in the number of inkjet dots based on the continuously collected pictures;

[0030] S5-4. If the number of inkjet dots within one stroke cycle of the scanning slide rail is within a small range б, it can be considered that the nozzle splicing is successful, and the debugging ends;

[0031] S5-5. If the fluctuation range of the number of inkjet dots in the collected picture is greater than б, the electronic magnifying collector stops in the middle of the slide rail. The control method for the middle stop is that the host computer gives a control signal to the scanning slide rail according to the collected picture, so that the overlapping area is located within the field of view D;

[0032] S5-6. Judge the positive or negative of the fluctuation value of the number of inkjet dots exceeding б within the field of view D. If the fluctuation value is positive, the dot density increases; if the fluctuation value is negative, the dot density decreases; if the fluctuation value is within the range of б, it means the alignment is correct and the debugging ends;

[0033] S5-7. If the dot density is positive, it means that the overlapping area of the nozzle holes is too large. At this time, calculate the width of the area with a higher dot density through Formula 1;

[0034] Nozzle deviation Formula 1

[0035] Explanation of Formula 1: The width of the effective collection field of view D is W, the length is L, the average number of spray dots within the field of view D under the condition of uniform dot distribution is n, and the number of dots collected within the field of view D is n D , n in Formula 1 D -n represents the difference between the number of collected dots within the collection field of view and the average number of dots n for uniform collection, is the ratio of the high-density area to the field of view area. Since the width W remains consistent within the field of view area D, the proportion of the high-density area is , so the width of the overlapping area, i.e., the positive offset of the nozzle, can be calculated through Formula 1;

[0036] S5-8. If the dot density is negative, it indicates that the overlapping area of the nozzle holes is too small. At this time, the width of the area with a lower dot density is calculated through Formula 2;

[0037] Nozzle deviation Formula 2

[0038] Explanation of Formula 2: The width of the effective field of view D collected is W, and the length is L. The average number of spray dots within the field of view D under the condition of uniform dot distribution is n, and the number of dots collected within the field of view D is n D , n in Formula 2 D -n represents the difference between the number of collected dots within the collected field of view and the average number of dots n collected uniformly, is the ratio of the nozzle deviation area to the field of view area. Since the width W remains consistent within the field of view area D, the proportion of the nozzle deviation area is , so the width of the nozzle deviation area, i.e., the negative offset of the nozzle, can be calculated through Formula 2;

[0039] S5-9. After the above process is completed, the nozzle stops moving for further scanning and judgment;

[0040] S5-10. The collecting slide rail is reset for re-jet coding verification, and the above process is repeated until the jet coding ink dots are evenly distributed.

[0041] Preferably, in S5-4, the value range of б is adjusted in the host computer program.

[0042] The beneficial effects of the present invention compared with the prior art are as follows:

[0043] It can magnify and collect the rasterized image printed by the spliced nozzle after preliminary adjustment, calculate the offset of the nozzle by calculating the dot density, feedback the nozzle offset to the nozzle adjustment micro-motor for adjustment, and form an information feedback closed loop through the above process, thereby automating the complex adjustment process and avoiding inaccurate situations caused by manual splicing of nozzles. Brief Description of the Drawings

[0044] Figure 1 is a schematic structural diagram of the magnifying collection control device of the present invention;

[0045] Figure 2 is a schematic flow diagram of the automatic adjustment of nozzle splicing of the present invention;

[0046] Figure 3It is a schematic diagram of the nozzle overlap of the present invention when it is greater than 15 pix;

[0047] Figure 4 It is a schematic diagram of the nozzle overlap of the present invention when it is less than 15 pix;

[0048] Figure 5 It is a schematic diagram of the nozzle overlap of the present invention when it is equal to 15 pix;

[0049] Figure 6 It is a schematic diagram of the method for the host computer to calculate the nozzle offset distance of the present invention;

[0050] Figure 7 It is a schematic diagram of the nozzle splicing method of the present invention;

[0051] Figure 8 It is a schematic diagram of the traditional manual debugging image setting;

[0052] Figure 9 It is a schematic diagram of the printing effect of the test image after traditional manual debugging.

[0053] Markings in the attached drawings: 1. Electronic amplification collector; 2. Scanning slide rail; 3. Test chart; 4. Host computer; 5. Control board; 6. Nozzle; 7. Micro motor. Detailed implementation manners

[0054] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant attached drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0055] Embodiment: As Figures 1 to 9 shown, a wide-format inkjet digital printing multi-nozzle splicing automatic adjustment method includes the following steps:

[0056] S1. Select the test chart debugging mode setting:

[0057] First, select a test picture in the software of the host computer ( Figure 1 4 in), match the corresponding test picture according to the common nozzle models in the market, and the corresponding relationship between the test picture and the nozzle mainly considers the printing width and length of different model nozzles. In the setting of the debugging mode, select the current test channel (select from the four colors of CMYK);

[0058] S2. Perform RIP (raster image processor) processing on the test chart:

[0059] The RIP processing is performed on the host computer ( Figure 1It is carried out in item 4) in [reference], and in the case of setting the debug mode, the RIP parameters are automatically set to the monochromatic 1x grid parameters (the RIP processing algorithm is the same as the traditional RIP processing method);

[0060] S3. The host computer sets the debug printing mode and sprays a test pattern:

[0061] Select the minimum ink droplet in the spraying settings. For example, select 6 pl for the ink droplet volume of the KJ4A nozzle. In the debug mode, it is necessary to set the number of nozzle hole overlaps of the spliced nozzles, which is set to 15 here. In the debug mode, through the encoder settings, the spraying positions of the nozzles that are not in the same horizontal direction are misaligned to facilitate the adjustment of the acquisition field of view, as Figure 3 shown. The enlarged acquisition effective field of view area is located within the scanning boundary, and the scanning boundary is horizontally located within the overlapping spraying area of the two nozzles;

[0062] S4. Magnified acquisition of the test pattern:

[0063] The electronic magnifying acquisition device ( Figure 1 in item 1) in [reference]) magnifies and acquires the test picture ( Figure 1 in item 3) in [reference]). An autofocus adjustable electronic magnifying acquisition device with a magnification of more than 100 times is selected according to the ink droplet size. During acquisition, the acquisition scanning boundary is parallel to the scanning slide rail ( Figure 1 in item 2) in [reference]). Its acquisition range is the horizontal overlapping part of the ink droplets sprayed by the two nozzles. The enlarged acquisition effective field of view range D is located within the acquisition scanning boundary and continuously acquired by moving horizontally within the scanning boundary;

[0064] S5. Shift discrimination calculation:

[0065] Set the encoder offset in the debug mode. If the printed rectangular monochromatic image forms an interleaved layout between the nozzles, through the halftone image formed by scanning with the electronic magnifying acquisition device ( Figure 1 in item 1) in [reference]), as Figure 3 shown, it indicates that the interleaved size between the nozzles is large. Similarly, as Figure 4 shown, it indicates that the interleaved size between adjacent nozzles is too small, Figure 5 indicating a 15 - pix docking;

[0066] When the electronic magnifying acquisition device scans, the electronic magnifying acquisition device ( Figure 1 in item 1) in [reference]) slides on the scanning slide rail ( Figure 1 in item 2) in [reference]) to scan the printed image. The scanning acquisition area is the longitudinal overlapping part of the ink droplets sprayed by the two nozzles, as Figure 3 shown, and the scanning result is fed back to the host computer, and the host computer discriminates according to the Figure 6 method;

[0067] The steps for the host computer to discriminate the scanning result are as follows:

[0068] S5-1. Identify the inkjet dots in the captured image within the field of view D;

[0069] S5-2. Calculate the number of inkjet dots within the field of view D based on the recognition result in S5-1;

[0070] S5-3. Compare the change in the number of inkjet dots based on continuously captured pictures;

[0071] S5-4. If the number of inkjet dots within one stroke cycle of the scanning slide rail ( Figure 1 No. 2 therein) is within a small range б (the value range of б is adjusted in the host computer program), it can be considered that the nozzle splicing is successful and the debugging ends;

[0072] S5-5. If the fluctuation range of the number of inkjet dots in the captured picture is greater than б, the electronic magnification collector stops in the middle of the slide rail ( Figure 9 No. 4 therein), and the control method for staying in the middle is that the host computer ( Figure 1 No. 4 therein) gives a control signal to the scanning slide rail ( Figure 1 No. 2 therein) according to the captured picture, so that the overlapping area is within the field of view D;

[0073] S5-6. Judge the positive or negative of the fluctuation value of the number of inkjet dots exceeding б within the field of view D ( Figure 6 No. 5 therein). If the fluctuation value is positive, the dot density increases; if the fluctuation value is negative, the dot density decreases; if the fluctuation value is within б, it means the alignment is correct and the debugging ends;

[0074] S5-7. If the dot density is positive, it means that the overlapping area of the nozzle holes is too large. At this time, calculate the width of the high dot density area through Formula 1 ( Figure 6 No. 6 therein);

[0075] Nozzle deviation Formula 1

[0076] Explanation of Formula 1: The width of the effective field of view D for acquisition is W, the length is L, the average number of inkjet dots within the field of view D under the condition of uniform dot distribution is n, and the number of dots within the acquired field of view D is n D , n D -n in Formula 1 represents the difference between the number of acquired points within the acquisition field of view and the average number of points n for uniform acquisition, is the proportion of the high-density area in the field of view area. Since the width W within the field of view area D remains the same, the proportion of the high-density area is , so the width of the overlapping area, that is, the positive offset of the nozzle, can be calculated through Formula 1;

[0077] S5-8. If the dot density is negative, it means that the overlapping area of the nozzle holes is too small. At this time, calculate the width of the low dot density area through Formula 2 ( Figure 6in 8);

[0078] Sprinkler deviation Formula 2

[0079] Explanation of Formula 2: The width of the effective acquisition field of view D is W, the length is L, and the average number of spray points in the field of view D under the condition of uniform point distribution is n, and the number of points collected in the field of view D is n D , n in Formula 2 D -n represents the difference between the number of collected points in the acquisition field of view and the average number of points n in uniform acquisition, is the ratio of the sprinkler deviation area to the field of view area. Since the width W within the field of view area D remains the same, the proportion of the sprinkler deviation area is , so the width of the sprinkler deviation area, that is, the negative offset of the sprinkler, can be calculated through Formula 2;

[0080] S5-9. After the above process is completed, the sprinkler stops moving ( Figure 6 in 10), and further scanning judgment is carried out;

[0081] S5-10. The acquisition slide rail is reset, and re-jet coding verification is carried out ( Figure 6 in 3), and the above process is repeated until the jet coding ink dots are evenly distributed ( Figure 6 in 10);

[0082] The present invention can magnify and collect the rasterized image printed by the spliced sprinkler after initial adjustment, calculate the offset of the sprinkler by calculating the dot density, feedback the sprinkler offset to the sprinkler adjustment micro-motor for adjustment, and form an information feedback closed loop through the above process, so as to automate the complex adjustment process and avoid the inaccurate situation caused by manual splicing of the sprinkler.

[0083] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for automatically adjusting the splicing of multiple nozzles in wide-format inkjet digital printing, characterized in that: The following steps are involved: S1. Select the test pattern debugging mode setting: First, select the test image in the host computer software. The correspondence between the test image and the print head mainly considers the printing width and length of different types of print heads. Select the current test channel in the debugging mode setting. S2. Perform RIP processing on the test image: RIP processing is performed on the host computer. When the debugging mode is set, the RIP parameters are automatically set to single-color 1x grid parameters; S3. The host computer sets the debugging printing mode and prints the test image: Select the smallest ink drop in the printing setting, and set the encoder so that there is no misalignment in the horizontal printing position of the nozzle, so as to adjust the acquisition field of view, and enlarge the acquisition effective field of view area to be located within the scanning boundary, and the scanning boundary is located horizontally in the overlapping printing area of ​​the two nozzles; S4. Test image magnification collection: The electronic magnifying collector magnifies and collects the test images. According to the ink droplet size, an electronic magnifying collector with an automatic focus adjustment of more than 100 times is selected; S5, shift discrimination calculation: In debug mode, set the encoder offset. If the printed rectangular monochrome image forms an interlaced layout between the print heads, the halftone image formed by scanning the electronic amplification collector indicates the size of the interlaced layout between the print heads. In S5, when the electronic amplifier and collector scans, the electronic amplifier and collector slides on the scanning slide rail to scan the printed image. The scanning and collecting area is the longitudinal overlapping part of the two nozzles, and the scanning result is fed back to the host computer, which determines the scanning result; The host computer performs the following steps to judge the scanning results: S5-1, identifying inkjet points on the image collected within the field of view D; S5-2, calculating the number of inkjet points within the visual range D according to the recognition result in S5-1; S5-3, comparing the changes in the number of inkjet points based on the continuously collected images; S5-4. If the number of inkjet points in one travel cycle of the scanning slide rail is within a small range, it can be considered that the nozzle splicing is successful and the debugging is ended; S5-5, if the fluctuation range of the number of inkjet points in the collected image is greater than б, the electronic amplification collector stays in the center of the slide rail, and the control method of the center stop is that the host computer gives the scanning slide rail control signal according to the collected image, so that the overlapping area is within the field of view D; S5-6, judging whether the number of inkjet dots in the field of view D exceeds the positive or negative value of the fluctuation value of б, if the fluctuation value is positive, the dot density increases, if the fluctuation value is negative, the dot density decreases, if the fluctuation value is within the range of б, it means that the alignment is correct, and the debugging is completed; S5-7, if the point density is a positive value, it means that the nozzle overlap area is too large. At this time, the width of the area with higher point density is calculated by formula 1; Nozzle deviation Formula 1 Formula 1 explanation: The width of the effective field of view D is W, the length is L, the average number of spray points in the field of view D is n under uniform point distribution, and the number of points collected in the field of view D is n D , n in formula 1 D -n represents the difference between the number of acquisition points in the acquisition field of view and the average number of uniform acquisition points n. is the proportion of high-density area to the viewing area. Since the width W of the viewing area D remains the same, the proportion of high-density area is , so the width of the overlapping area, that is, the positive offset of the nozzle, can be calculated by formula 1; S5-8, if the point density is a negative value, it means that the nozzle overlap area is too small. In this case, the width of the area with lower point density is calculated by formula 2; Nozzle deviation ; Formula 2 Formula 2 explanation: The width of the effective field of view D is W, the length is L, the average number of spray points in the field of view D is n under uniform point distribution, and the number of points collected in the field of view D is n D , n in formula 2 D -n represents the difference between the number of acquisition points in the acquisition field of view and the average number of uniform acquisition points n. is the ratio of the nozzle deviation area to the field of view area. Since the width W of the field of view area D remains the same, the ratio of the nozzle deviation area is , so the width of the nozzle deviation area, that is, the negative offset of the nozzle, can be calculated by formula 2; S5-9, after the above process is completed, the nozzle stops moving and performs further scanning judgment; S5-10, reset the collection rail, and re-print the code for verification. Repeat the above process until the coding ink dots are evenly distributed.

2. The automatic adjustment method for splicing multiple nozzles in wide-format inkjet digital printing according to claim 1, characterized in that: The test channel in S1 is selected from the four colors of CMYK.

3. The automatic adjustment method for splicing multiple nozzles in wide-format inkjet digital printing according to claim 1, characterized in that: In S4, during acquisition, the acquisition scanning boundary is parallel to the scanning slide rail, and the acquisition range is the lateral overlapped portion of the ink droplets printed by the two nozzles. The enlarged acquisition effective field of view range D is located within the acquisition scanning boundary and is continuously acquired by lateral movement at the scanning boundary.

4. The automatic adjustment method for splicing multiple nozzles in wide-format inkjet digital printing according to claim 1, characterized in that: In S5-4, the value range of б is adjusted in the upper computer program.

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