Multi-nozzle splicing automatic adjusting method for wide-width ink-jet digital printing

Abstract

The invention relates to the technical field of wide-width ink-jet digital printing multi-nozzle splicing, in particular to a wide-width ink-jet digital printing multi-nozzle splicing automatic adjusting method. Comprising the following steps: selecting test chart debugging mode setting, carrying out RIP processing on a test chart, setting a debugging printing mode by an upper computer, carrying out jet printing on the test chart, amplifying and collecting the test chart, and carrying out displacement discrimination calculation; the system can amplify and collect rasterized images sprayed and printed by the spliced spray head after initial adjustment, calculate the offset of the spray head by calculating the point density, and feed back the offset of the spray head to the spray head adjusting micromotor for adjustment, and an information feedback closed loop is formed through the above processes, so that the complex adjusting process is automated, and the efficiency is improved. And the situation of inaccuracy caused by manual splicing of the nozzles is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of wide-format inkjet digital printing multi-nozzle splicing, and in particular to an automatic adjustment method for wide-format inkjet digital printing multi-nozzle splicing. Background Art

[0002] A wide-format inkjet digital printer is a device used for large-format printing and is widely used in advertising, decoration, art and other fields. Existing wide-format inkjet digital printers, such as a new type of micro-piezoelectric wide-format inkjet printer disclosed in the patent with announcement number CN201931720U and a digital printing device for the printing manufacturing industry disclosed in the patent with announcement number CN215204071U, can all realize inkjet printing.

[0003] However, it was found during use that the existing wide-format inkjet digital printing machine has a relatively simple structure and needs to be connected to the nozzles before use. The traditional nozzle splicing method is: 1. Calculate the nozzle spacing according to the nozzle parameters, and design and process the limit plate according to the number of cross nozzles; 2. Install the nozzle in a triangle shape on the limit plate (such as Figure 7 shown); 3. The software is set to print the standard test chart. The printed test chart is usually a cross straight line (such as Figure 8 shown); 4. Manually fine-tune the nozzle position according to the misalignment of the straight line; 5. Repeat step 4 until the test line prints successfully (such as Fig. 9 as shown).

[0004] The spacing between nozzles is on the order of microns, so the docking quality has a great impact on the quality of inkjet printing. The nozzle assembly is fine-tuned by relying on the experience of the debugging personnel, and the above process is repeated until a qualified test image is printed. This process cannot automatically adjust the nozzle position through the feedback of the equipment, so it is highly dependent on the debugging personnel. It often takes a long time to debug successfully, and the quality of equipment debugging cannot be guaranteed, resulting in poor practicality. Therefore, an automatic adjustment method for multi-nozzle splicing in wide-format inkjet digital printing is urgently needed to improve the above problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for automatically adjusting multi-nozzle splicing in wide-format inkjet digital printing, which can enlarge and collect the rasterized image printed by the spliced ​​nozzles after initial adjustment, infer the offset of the nozzle by calculating the dot density, and feed back the offset of the nozzle to the nozzle adjustment micromotor for adjustment. The above process forms an information feedback closed loop, thereby automating the complex adjustment process and avoiding the inaccuracy caused by manual splicing of the nozzles.

[0006] The invention discloses a method for automatically adjusting the splicing of multiple nozzles in wide-format inkjet digital printing, comprising the following steps: S1. Select the test pattern debugging mode setting: First, select the test image in the upper computer software, and match the corresponding test image according to the common nozzle models on the market. The correspondence between the test image and the nozzle mainly considers the printing width and length of different nozzle models. 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. Preferably, the test channel in S1 is selected from the four colors of CMYK.

[0007] Preferably, the RIP processing algorithm in S2 is the same as the traditional RIP processing method.

[0008] Preferably, in said S4, during acquisition, the acquisition scanning boundary is parallel to the scanning slide rail, and the acquisition range is the lateral overlapping portion of the ink droplets printed by the two nozzles, and the enlarged acquisition effective field of view range D is located within the acquisition scanning boundary and continuously acquires by moving laterally along the scanning boundary.

[0009] Preferably, in S5, when the electronic amplifier and collector scans, the electronic amplifier and collector slides on the scanning 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 judges the scanning result.

[0010] Preferably, the host computer performs the following steps to determine 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.

[0011] Preferably, in S5-4, the value range of б is adjusted in the upper computer program.

[0012] Compared with the prior art, the present invention has the following beneficial effects: It is able to enlarge and collect the rasterized image printed by the spliced ​​nozzles after the initial adjustment, infer the offset of the nozzle by calculating the dot density, and feed the nozzle offset back to the nozzle adjustment micromotor for adjustment. The above process forms an information feedback closed loop, thereby automating the complex adjustment process and avoiding the inaccuracy caused by manual splicing of the nozzles. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the amplification and collection control device of the present invention; Figure 2 It is a schematic diagram of the automatic adjustment process of the nozzle splicing of the present invention; Figure 3 This is a schematic diagram of the present invention when the nozzle overlap is greater than 15pix; Figure 4 is a schematic diagram of the present invention when the nozzle overlap is less than 15 pix; Figure 5 This is a schematic diagram of the present invention when the nozzle overlap is equal to 15pix; Figure 6 Schematic diagram of the method for calculating the nozzle offset distance by the host computer of the present invention; Figure 7 It is a schematic diagram of the nozzle splicing method of the present invention; Figure 8 This is a schematic diagram of traditional manual debugging image settings; Fig. 9 It is a schematic diagram of the test image printing effect after traditional manual debugging.

[0014] Markings in the attached figure: 1. Electronic amplifier collector; 2. Scanning slide rail; 3. Test chart; 4. Host computer; 5. Control board; 6. Printhead; 7. Micro motor. DETAILED DESCRIPTION

[0015] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0016] Example: Figures 1 to 9 As shown, a method for automatically adjusting the splicing of multiple nozzles in wide-format inkjet digital printing includes the following steps: S1. Select the test pattern debugging mode setting: First on the host computer ( Figure 1 4) Select the test image in the software, match the corresponding test image according to the common nozzle models on the market. The correspondence between the test image and the nozzle mainly considers the printing width and length of different nozzle models. Select the current test channel in the debugging mode setting (select from CMYK four colors); S2. Perform RIP (Raster Image Processor) processing on the test image: RIP processing on the host computer ( Figure 1 In 4), when setting the debugging mode, the RIP parameters are automatically set to monochrome 1x grid parameters (the RIP processing algorithm is the same as the traditional RIP processing method); S3. The host computer sets the debugging printing mode and prints the test image: Select the minimum ink drop in the printing setting, for example, select 6pl for the ink drop volume of the KJ4A nozzle. In the debugging mode, you need to set the number of nozzle overlaps of the spliced ​​nozzles, which is set to 15 here. In the debugging mode, the encoder is set to prevent the nozzles from being misaligned in a horizontal printing position, so as to adjust the acquisition field of view. Figure 3 As shown, the enlarged acquisition effective field of view is located within the scanning boundary, and the scanning boundary is laterally located within the overlapping printing area of ​​the two print heads; S4. Test image magnification collection: Electronic amplifier collector ( Figure 1 1) For the test image ( Figure 1 3) in the above, magnify the data and select an electronic magnification collector with an automatic focus adjustment of more than 100 times according to the ink droplet size. When collecting, collect the scan boundary and the scan rail ( Figure 1 2) Parallel, the acquisition range is the lateral overlap of the ink droplets printed by the two nozzles, the enlarged acquisition effective field of view D is located within the acquisition scanning boundary and moves horizontally across the scanning boundary for continuous acquisition; 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 electronic amplifier collector ( Figure 1 1) The halftone image formed by scanning, such as Figure 3 As shown, it means that the staggered size between the nozzles is large. Similarly, Figure 4 The figure shows that the staggered size of adjacent nozzles is too small. Figure 5 It means that 15pix docking has been achieved; When the electronic amplifier is scanning, the electronic amplifier ( Figure 1 1) In the scanning slide ( Figure 1 Slide on 2) in the figure to scan the printed image. The scanning and collection area is the longitudinal overlapping part of the two nozzles. Figure 3 As shown, the scanning results are fed back to the host computer, which Figure 6 Method for identification; 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 scanning slide rail ( Figure 1 2) If the number of inkjet points in one stroke cycle is within a small range of 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 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 ( Fig. 9 4), the control method of centering is the host computer ( Figure 1 4) According to the collected pictures, the scanning slide rail ( Figure 1 2) Control the signal so that the overlapping area is within the field of view D; S5-6, determine whether the fluctuation value of the number of inkjet dots in the field of view D exceeds б ( Figure 6 5) If the fluctuation value is positive, the point density increases; if the fluctuation value is negative, the point 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 positive, it means that the nozzle overlap area is too large. In this case, the width of the area with higher point density is calculated by formula 1 ( Figure 6 6 in ); 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 negative, 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 ( Figure 6 8 in ); 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 ( Figure 6 10) to make further scanning decisions; S5-10, reset the collection rail and perform re-inking verification ( Figure 6 3), repeat the above process until the ink dots are evenly distributed ( Figure 6 of 10); The present invention can enlarge and collect the rasterized image printed by the spliced ​​nozzles after initial adjustment, infer the offset of the nozzle by calculating the point density, and feed back the offset of the nozzle to the nozzle adjustment micromotor for adjustment. The above process forms an information feedback closed loop, thereby automating the complex adjustment process and avoiding the inaccuracy caused by manual splicing of the nozzles.

[0017] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection 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 upper computer software, and match the corresponding test image according to the common nozzle models on the market. The correspondence between the test image and the nozzle mainly considers the printing width and length of different nozzle models. 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: Set the encoder offset in debug mode. If the printed rectangular monochrome image forms an interlaced layout between the print heads, the halftone image formed by scanning the electronic amplification collector represents the size of the interlaced layout between the print heads.

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: The RIP processing algorithm in S2 is the same as the traditional RIP processing method.

4. 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.

5. The automatic adjustment method for splicing multiple nozzles in wide-format inkjet digital printing according to claim 1, characterized in that: 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 judges the scanning result.

6. The automatic adjustment method for splicing multiple nozzles in wide-format inkjet digital printing according to claim 5, characterized in that: 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.

7. The automatic adjustment method for splicing multiple nozzles in wide-format inkjet digital printing according to claim 6, characterized in that: In S5-4, the value range of б is adjusted in the upper computer program.

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