Double-sided inkjet printing method, device and equipment

Abstract

The present invention discloses a double-sided inkjet printing method, device and equipment, and relates to the field of inkjet printing technology. The method is based on a driving mechanism to drive a first printing carriage and a second printing carriage to move synchronously toward or in the opposite direction at the same printing height to realize simultaneous printing on the front and back sides of a printing medium. Compared with the existing double-sided inkjet printing technology, it does not need to wait for the ink to dry or perform additional flipping operations, which can significantly shorten the printing time and improve the printing efficiency. When the front and back sides are printed synchronously, the time and position of the ink penetrating into the front and back sides of the printing medium are close, thereby reducing the tension difference between the front and back sides caused by the ink penetrating successively, reducing the influence of the tension difference on the printing effect, and helping to improve the printing quality. In addition, the data processing method during printing in the method of the present invention is simple and efficient, which can better meet the needs of double-sided inkjet printing, improve the printing quality and efficiency, and improve user satisfaction.

Description

Technical Field

[0001] The present invention relates to the technical field of inkjet printing, and in particular to a double-sided inkjet printing method, device and equipment. Background Art

[0002] In digital inkjet printing applications, double-sided inkjet printing is a technology that forms images by inkjetting on both sides of a printing medium such as paper, textile fabrics, glass, acrylic, etc. Conventional inkjet printing equipment can only spray ink on one side of the printing medium, and the other side needs to wait for the ink to dry before flipping and printing, which wastes time. In addition, please refer to the double-sided printing method disclosed in the patent document with application publication number "CN109334254A" and patent name "Double-sided printing method and double-sided printing machine". The existing double-sided printing needs to be completed through a complex cloth-feeding structure and the use of two scanning mechanisms on the front and back sides, that is, first control the front scanning mechanism, i.e., the first printing carriage, to inkjet print the front side, and then, with the assistance of the cloth-feeding roller, the reverse scanning mechanism, i.e., the second printing carriage, can perform inkjet printing on the reverse side, thereby achieving double-sided printing. This printing method has the following defects: if one side is printed first and the ink is infiltrated first, the side that is infiltrated with ink will have obvious changes in tension and quality, resulting in different tensions on both sides of the printing medium, which will affect the accuracy of the transmission system or the material retracting and unwinding system on the front and back sides. In addition, since two scanning mechanisms are used, two positioning mechanisms (such as grating rulers) are required to position the nozzle ignition. The mechanical rigidity and error consistency of the two positioning mechanisms are difficult to guarantee, which will also cause errors in double-sided image printing and affect the printing quality. Summary of the invention

[0003] In view of this, embodiments of the present invention provide a double-sided inkjet printing method, device and equipment to solve the problems of low efficiency and poor printing quality of double-sided inkjet printing in the prior art.

[0004] In a first aspect, an embodiment of the present invention provides a double-sided inkjet printing method, which is applied to a double-sided inkjet printing device, wherein the double-sided inkjet printing device includes a first printing carriage and a second printing carriage, a printing medium is vertically arranged between the first printing carriage and the second printing carriage, the first printing carriage and the second printing carriage can reciprocate along a main scanning direction under the drive of the same driving mechanism, the first printing carriage is used to spray ink onto the front side of the printing medium to form an image, and the second printing carriage is used to spray ink onto the reverse side of the printing medium to form an image, and the method includes:

[0005] Acquire an image to be printed, and perform rasterization processing on the image to be printed to obtain first printing data;

[0006] Expanding the first printing data to obtain second printing data;

[0007] extracting third printing data and fourth printing data respectively from the second printing data;

[0008] Processing the fourth printing data to obtain fifth printing data;

[0009] The third printing data and the fifth printing data are sent to the first printing carriage and the second printing carriage respectively, the first printing carriage and the second printing carriage are driven to move synchronously towards or in opposite directions at the same printing height, and ink is sprayed onto the front and back sides of the printing medium respectively to form an image.

[0010] Preferably, the first print data includes first black channel data, first cyan channel data, first magenta channel data and first yellow channel data, each having N lines, and the step of expanding the first print data to obtain the second print data includes:

[0011] Copy the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data of the i-th line in the first print data respectively, and obtain the second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data of the i-th line;

[0012] Insert the second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data of the i-th line between the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data of the i-th line and the i+1-th line to obtain the second printing data;

[0013] Wherein i=0,1,2,...N-1, N is a natural number greater than or equal to 1.

[0014] Preferably, the extracting the third printing data and the fourth printing data from the second printing data respectively comprises:

[0015] extracting the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data from the second printing data in sequence according to the number of lines as the third printing data;

[0016] The second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data which correspond one to one with the number of lines of the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data in the third print data are extracted from the second print data as the fourth print data.

[0017] Preferably, the performing data processing on the fourth printing data to obtain the fifth printing data comprises:

[0018] Performing mirror processing on the fourth printing data to obtain mirror printing data;

[0019] Determining whether the end of each line of data in the mirror print data contains blank data;

[0020] If yes, placing the blank data at the front of each line of data to obtain the fifth printing data;

[0021] If not, the mirror image printing data is the fifth printing data.

[0022] Preferably, after processing the fourth print data to obtain the fifth print data, the method further includes:

[0023] Control the first printing carriage and the second printing carriage to print a first test image and a second test image on the front and back sides of the printing medium respectively according to the third printing data and the fifth printing data;

[0024] Acquire a vertical alignment deviation between the first test image and the second test image;

[0025] inserting or deleting a number of blank data at the front end of each line of data in the third printing data and / or the fifth printing data according to the vertical alignment deviation;

[0026] and / or:

[0027] Acquire a horizontal alignment deviation between the first test image and the second test image;

[0028] Several lines of blank data are inserted or deleted in the third printing data and / or the fifth printing data according to the horizontal alignment deviation.

[0029] Preferably, before sending the third printing data and the fifth printing data to the first printing carriage and the second printing carriage respectively, driving the first printing carriage and the second printing carriage to synchronously move toward each other from both ends of the printing medium at the same printing height and spraying ink onto the front and back sides of the printing medium to form an image, the method further includes:

[0030] Obtaining a maximum scanning width of the first printing carriage in the main scanning direction, recorded as a first width;

[0031] Acquire the width of the image to be printed in the main scanning direction, recorded as a second width;

[0032] The starting printing positions of the first printing carriage and the second printing carriage are obtained according to the first width and the second width.

[0033] Preferably, the first printing data is composed of dot data, and before the first printing data is expanded to obtain the second printing data, the method further includes:

[0034] Acquire the total ink volume corresponding to the first printing data;

[0035] Determine preferred values ​​of the amount of ink carried by the front side and the back side of the printing medium, respectively, and record them as a first preferred ink amount and a second preferred ink amount;

[0036] The ink volume value corresponding to the dot data is adjusted according to the total ink volume, the first preferred ink volume, and the second preferred ink volume.

[0037] Preferably, the dot data includes large ink dot data, medium ink dot data and small ink dot data, and the corresponding ink amounts are recorded as a first ink amount, a second ink amount and a third ink amount respectively, wherein the first ink amount> the second ink amount> the third ink amount, and the adjusting the ink amount value corresponding to the dot data according to the total ink amount and the first preferred ink amount and the second preferred ink amount includes:

[0038] Determine whether a first difference between the total ink volume and the first preferred ink volume is greater than or equal to a preset threshold and / or whether a second difference between the total ink volume and the second preferred ink volume is greater than or equal to the preset threshold;

[0039] If yes, obtaining an ink volume adjustment value according to the first difference and / or the second difference;

[0040] Any one or more of the first ink amount, the second ink amount, and the third ink amount are adjusted according to the ink amount adjustment value.

[0041] In a second aspect, an embodiment of the present invention provides a double-sided inkjet printing device, which is applied to a double-sided inkjet printing device, wherein the double-sided inkjet printing device includes a first printing carriage and a second printing carriage, a printing medium is vertically arranged between the first printing carriage and the second printing carriage, the first printing carriage and the second printing carriage can reciprocate along the main scanning direction under the drive of the same driving mechanism, the first printing carriage is used to spray ink to the front side of the printing medium to form an image, and the second printing carriage is used to spray ink to the back side of the printing medium to form an image, and the device includes:

[0042] A data acquisition module, used for acquiring an image to be printed, and performing rasterization processing on the image to be printed to obtain first printing data;

[0043] A data expansion module, used for expanding the first printing data to obtain second printing data;

[0044] A data extraction module, used for respectively extracting third printing data and fourth printing data from the second printing data;

[0045] A data processing module, used for processing the fourth printing data to obtain fifth printing data;

[0046] The printing module is used to send the third printing data and the fifth printing data to the first printing carriage and the second printing carriage respectively, drive the first printing carriage and the second printing carriage to move synchronously towards or in opposite directions at the same printing height, and respectively spray ink onto the front and back sides of the printing medium to form an image.

[0047] In a third aspect, an embodiment of the present invention provides a double-sided inkjet printing device, wherein the double-sided inkjet printing device comprises a first printing carriage and a second printing carriage, a printing medium is vertically arranged between the first printing carriage and the second printing carriage, the first printing carriage and the second printing carriage can reciprocate along the main scanning direction under the drive of the same driving mechanism, the first printing carriage is used to spray ink onto the front side of the printing medium to form an image, and the second printing carriage is used to spray ink onto the back side of the printing medium to form an image; the double-sided inkjet printing device also includes: at least one processor, at least one memory and computer program instructions stored in the memory, and when the computer program instructions are executed by the processor, the method of the first aspect in the above-mentioned embodiment is implemented.

[0048] In a fourth aspect, an embodiment of the present invention provides a storage medium having computer program instructions stored thereon, which implements the method of the first aspect in the above-mentioned embodiment when the computer program instructions are executed by a processor.

[0049] In summary, the beneficial effects of the present invention are as follows:

[0050] The double-sided inkjet printing method, device and equipment provided by the embodiment of the present invention are based on a driving mechanism to drive the first printing carriage and the second printing carriage to move synchronously toward or in the opposite direction at the same printing height to realize simultaneous printing on the front and back sides of the printing medium. Compared with the existing double-sided inkjet printing technology, there is no need to wait for the ink to dry or perform additional flipping operations, which can significantly shorten the printing time and improve the printing efficiency. When the front and back sides are printed synchronously, the time and position of the ink penetrating into the front and back sides of the printing medium are close, thereby reducing the tension difference between the front and back sides caused by the ink penetrating successively, reducing the influence of the tension difference on the printing effect, and helping to improve the printing quality. In addition, the data processing method during printing in the method of the present invention is simple and efficient, which can better meet the needs of double-sided inkjet printing, improve the printing quality and efficiency, and improve user satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings required for use in the embodiment of the present invention will be briefly introduced below. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work, and these are all within the protection scope of the present invention.

[0052] Figure 1 Schematic diagram of the structure of a double-sided inkjet printing device in an embodiment of the present invention.

[0053] Figure 2 It is a schematic diagram of the placement of the printing medium in the embodiment of the present invention.

[0054] Figure 3 Schematic diagram of the double-sided inkjet printing method in an embodiment of the present invention.

[0055] Figure 4 4 is a schematic diagram of first printing data in an embodiment of the present invention.

[0056] Figure 5 is a schematic diagram of second printing data in an embodiment of the present invention.

[0057] Figure 6 Schematic diagram of the misalignment of the front and back images in an embodiment of the present invention.

[0058] Figure 7 It is a schematic diagram of data processing in an embodiment of the present invention.

[0059] Figure 8a Schematic diagram of alignment of front and back images in an embodiment of the present invention.

[0060] Figure 8b is a schematic diagram of alignment deviation in an embodiment of the present invention.

[0061] Fig. 9 It is a schematic diagram of center printing in an embodiment of the present invention.

[0062] Fig.10 It is a schematic structural diagram of a double-sided inkjet printing device according to an embodiment of the present invention.

[0063] Fig.11 It is a structural schematic diagram of a control system of a double-sided inkjet printing device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0064] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0065] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0066] Embodiment 1

[0067] The embodiment of the present invention provides a double-sided inkjet printing device, such as Figure 1 As shown, the double-sided inkjet printing device includes a first printing carriage 5, a second printing carriage 6, and a beam 4. The beam 4 is provided with a synchronous belt 3, a driving wheel 1, and a driven force 2. The driving mechanism (not shown) drives the driving wheel 1 to rotate and drives the driven wheel 2 to rotate through the synchronous belt 3. The first printing carriage 5 and the second printing carriage 6 are both installed on the synchronous belt 3 of the beam 4 and are respectively arranged on both sides of the beam 4. For example, the first printing carriage 5 is installed on the front side 41 and the second printing carriage 6 is installed on the rear side 42. The synchronous belt 3 can drive the first printing carriage 5 to reciprocate along the main scanning direction X (also called the printing direction) at the front side 41 and the second printing carriage 6 to reciprocate at the rear side 42. The double-sided inkjet printing system provided by the embodiment of the present invention does not require a double beam, a double control system, and a double drive structure, which can effectively reduce costs, so that high-quality double-sided inkjet printing effects can be achieved under low-cost machine structure and control system conditions.

[0068] like Figure 2As shown, when double-sided printing is required, the printing medium 8 passes through the crossbeam 4 and the synchronous belt 3 and is vertically (perpendicular to the horizontal plane) arranged between the first printing carriage 5 and the second printing carriage 6. Preferably, the printing origins (i.e., the printing starting points) of the first printing carriage 5 and the second printing carriage 6 are respectively arranged at the two ends of the crossbeam 4, such as the printing origin of the first printing carriage 5 is arranged at the right end 43 of the crossbeam 4, and the printing origin of the second printing carriage is arranged at the left end 44 of the crossbeam 4. When the driving structure drives the driving wheel 1 to rotate and drives the first printing carriage 5 to move from left to right through the synchronous belt 3, it drives the second printing carriage 6 to move synchronously from left to right. Since the first printing carriage 5 and the second printing carriage 6 are arranged on the same crossbeam, their printing heights relative to the printing medium are the same, so that inkjet printing is performed on both sides of the printing medium at the same time and at the same height position, and the time and position of ink penetrating the front and back sides of the printing medium are close, thereby reducing the tension difference between the front and back sides caused by the ink penetrating successively, and reducing the influence of the tension difference on the printing effect. In addition, the data sending method of this double-sided inkjet printing device during printing is similar to that of a single-sided inkjet printing device. Only special data processing is required for the printing data on the back side, which greatly reduces development costs and trial-and-error costs. It can help users quickly switch from single-sided printing to double-sided printing, minimize the development cycle and trial-and-error costs, and bring users faster economic benefits of rapid iteration.

[0069] Based on the above double-sided inkjet printing equipment, please see Figure 3 The embodiment of the present invention further provides a double-sided inkjet printing method, and the double-sided inkjet printing method specifically includes:

[0070] S1: Acquire an image to be printed, and perform rasterization processing on the image to be printed to obtain first printing data;

[0071] S2: Expanding the first printing data to obtain second printing data;

[0072] S3: extracting third printing data and fourth printing data respectively from the second printing data;

[0073] S4: Processing the fourth printing data to obtain fifth printing data;

[0074] S5: Send the third printing data and the fifth printing data to the first printing carriage and the second printing carriage respectively, drive the first printing carriage and the second printing carriage to move synchronously towards or in opposite directions at the same printing height, and respectively spray ink onto the front and back sides of the printing medium to form an image.

[0075] In the embodiment of the present invention, a double-sided image with the same front and back sides and mirror images of each other is printed on a printing medium as an example to illustrate how to control the double-sided inkjet printing device to perform double-sided printing. Specifically, first obtain the image to be printed, where the image to be printed can be a bitmap or a vector. The image to be printed is input into the image rasterization processor (such as RIP software) of the host computer (such as a PC) of the double-sided inkjet printing device for rasterization processing, and then the print data in the PRN format that can be recognized by the double-sided inkjet printing device is obtained, which is recorded as the first print data. Since double-sided printing is required, the first print data is only sufficient for printing on one side, so it is necessary to expand the first print data to obtain print data sufficient for double-sided printing. After the first print data is expanded, the second print data for double-sided printing is obtained. When printing, the second print data needs to be split while printing. The third print data for printing the front side of the second print data is extracted and distributed to the first print carriage. The fourth print data for printing the back side is extracted and distributed to the second print carriage. Since the back side image is a mirror image of the front side image, the fourth print data is processed before being sent to the second print carriage to obtain the fifth print data, so that the image can be correctly printed on the back side of the print medium. In addition, in order to reduce the influence of tension difference on the printing effect, in an embodiment of the present invention, the first print carriage and the second print carriage are respectively set at the two ends of the print medium before printing, such as Figure 2As shown, the first printing carriage is arranged at the left end of the printing medium, and the second printing carriage is arranged at the right end of the printing medium. The printing (position) heights of the first printing carriage and the second printing carriage are the same. After the first printing carriage receives the third printing data, it starts inkjet printing from the printing starting point on the front side of the right end of the printing medium. Similarly, the second printing carriage receives the fifth printing data and starts inkjet printing from the printing starting point on the back side of the left end of the printing medium. Since the first printing carriage and the second printing carriage are both installed on the same synchronous belt, when the first printing carriage is driven to move from right to left (scan) on the front side of the printing medium for a PASS printing, the second printing carriage will be synchronously driven to move from left to right (scan) on the rear side of the beam for a PASS printing on the back side of the printing medium. After one PASS printing is completed, the print medium is controlled to move a certain distance relative to the beam along the secondary scanning direction Y (or stepping direction), and the first print carriage is controlled to move from left to right in front of the beam to print the next PASS on the front side of the print medium. Similarly, the second print carriage is driven to move from right to left behind the beam to print the next PASS on the back side of the print medium... The first print carriage and the second print carriage are controlled to move back and forth in this way until the image printing on both sides is completed. In each PASS printing, the printing area on both sides is highly consistent, and the time and position of the ink penetrating the front and back sides of the print medium are close, thereby reducing the tension difference between the front and back sides caused by the ink penetrating successively, reducing the influence of the tension difference on the printing effect, and helping to improve the printing quality.

[0076] In one embodiment, the image to be printed is a color image. Color images are usually printed using C (cyan) M (magenta) Y (yellow) K (black) ink. The first print data obtained after rasterizing the image to be printed includes first black channel data, first cyan channel data, first magenta channel data, and first yellow channel data. Figure 4 The figure shows an example of the data format of the first printing data: the file header plus each line of data of each color channel. Each line of color channel data corresponds to the ink dot data corresponding to each pixel row of the printed image. For example, the first black channel data of line 0 corresponds to the black ink dot data of the pixel of line 0 in the front image, and the first cyan channel data of line 0 corresponds to the cyan ink dot data of the pixel of line 0 in the front image... Black, cyan, magenta and yellow ink dots form a color image from a macroscopic point of view.

[0077] In the implementation of the present invention, the printed images on both sides are identical and are mirror images. Preferably, the step of expanding the first printing data to obtain the second printing data includes:

[0078] Copy the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data of the i-th line in the first print data respectively, and obtain the second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data of the i-th line;

[0079] Insert the second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data of the i-th line between the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data of the i-th line and the i+1-th line to obtain the second printing data;

[0080] Wherein i=0,1,2,...N-1, N is a natural number greater than or equal to 1.

[0081] Specifically, Figure 5 As shown, the first black channel data, the first cyan channel data, the first magenta channel data, and the first yellow channel data of the 0th, 1st, ..., N-1th lines are copied respectively to obtain the second black channel data, the second cyan channel data, the second magenta channel data, and the second yellow channel data of the corresponding lines, and the second black channel data, the second cyan channel data, the second magenta channel data, and the second yellow channel data of the i-th line are inserted between the first black channel data, the first cyan channel data, the first magenta channel data, and the first yellow channel data of the i-th and i+1-th lines, to finally obtain the expanded second print data.

[0082] According to the second printing data, the front and back images can be printed. When printing, the second printing data needs to be split while printing, and the third printing data used for printing the front side of the second printing data is extracted and distributed to the first printing carriage, and the fourth printing data used for printing the back side is extracted and distributed to the second printing carriage. Preferably, the extracting the third printing data and the fourth printing data from the second printing data respectively includes:

[0083] extracting the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data from the second printing data in sequence according to the number of lines as the third printing data;

[0084] Second black channel data, second cyan channel data, second magenta channel data and second yellow channel data corresponding to the number of lines of first black channel data, first cyan channel data, first magenta channel data and first yellow channel data in the third print data are extracted from the second print data as the fourth print data.

[0085] Specifically, during printing, the control software of the double-sided inkjet printing device will extract the corresponding number of lines of data from the second printing data according to the amount of data printed in each PASS and send them to the printing carriage. If a PASS of printing data includes 1 line of each color channel data, then the first black channel data, the first cyan channel data, the first magenta channel data, and the first yellow channel data of the first line will be first extracted from the second printing data (recorded as the third printing data) and sent to the first printing carriage. Similarly, the second black channel data, the second cyan channel data, the second magenta channel data, and the second yellow channel data of the corresponding number of lines, i.e., the 0th line, will be extracted (recorded as the fourth printing data) and sent to the second printing carriage. In the next PASS, the first black channel data, the first cyan channel data, the first magenta channel data, and the first yellow channel data of the first line (the third printing data) will be extracted and sent to the first printing carriage. Similarly, the second black channel data, the second cyan channel data, the second magenta channel data, and the second yellow channel data of the corresponding number of lines, i.e., the 1st line (the fourth printing data) will be extracted and sent to the second printing carriage.

[0086] Since the back image corresponds to the front image in a mirror image, the fourth print data is processed to obtain the fifth print data before being sent to the second print carriage. Preferably, the processing of the fourth print data to obtain the fifth print data includes:

[0087] Performing mirror processing on the fourth printing data to obtain mirror printing data;

[0088] Determining whether the end of each line of data in the mirror print data contains blank data;

[0089] If yes, placing the blank data at the front of each line of data to obtain the fifth printing data;

[0090] If not, the mirror image printing data is the fifth printing data.

[0091] Specifically, before data processing, the fourth print data and the third print data are the same. Since it is necessary to realize mirror printing of double-sided images, the fourth print data needs to be mirrored, and the data processing is generally performed in the print control software of the host computer of the double-sided inkjet printing device. The end of each line of color channel data in the third print data and the fourth print data may contain blank data. The blank data does not drive the nozzle to spray ink. When the print control software performs mirror processing on the fourth print data, it will not perform mirror processing on the blank data, but will perform mirror processing on each line of non-blank data and then set the blank data at the end of the non-blank data. Such processing will result in an image printing result like Figure 6As shown, assuming that the printing starting point is the edge of the printing medium, after printing according to the third printing data, the starting printing position 9 of the front image 11 is at the right edge of the printing medium. Since there is blank data at the end, there are some blank pixels 13 (blank image) at the left edge. After the fourth printing data is mirrored, the blank data is still set at the end of each line of data. When printing the back image, the starting printing position 10 of the back image 12 is at the left edge of the printing medium, and there will be some blank pixels 14 (blank image) at the right edge of the back image, resulting in the front and back images cannot be aligned. If the printing medium is a transparent material, this misalignment will greatly affect the double-sided printing effect. For example, assuming that the width of the image after rasterization is 6434 pixels, the number of bytes corresponding to each line of color channel data is 1612 bytes, and variable dot printing is used (2-bit screening, large, medium and small ink dots can be used for printing), then 1 pixel requires 2 bits (2 bits) to represent, and 1 byte (8 bits) can represent 4 pixels. The bytes corresponding to each line of color channel data can store 1612*4=6448 pixels, that is, there are 6448-6434=14 pixels that are blank pixels. Since 1 pixel occupies 2 bits, there are 14*2=28 bits of data that are blank data. If the printing accuracy is 360dpi, 14 / 360*25.4=0.988 mm, that is, the front and back sides of the image will cause an alignment error of nearly 1 mm.

[0092] In order to ensure the image printing quality, preferably, it is determined whether the end of each line of data in the fourth printing data after the mirroring process contains blank data. If so, the blank data needs to be moved to the front of each line of data, and the fifth printing data is obtained after the data processing. Figure 7 As shown in FIG. 1 , there is blank data 0 in the last byte, the Kth byte. In actual situations, the blank data of the mirror-printed data after mirror processing is still at the end, i.e., the Kth byte. At this time, the blank data needs to be moved to the front of the row of data to obtain the final fifth print data. After data processing, the front and back images are obtained as shown in FIG. Figure 8a As shown, the blank pixels 13 of the front image 12 and the blank pixels 14 of the back image 12 are both at the left edge of the printing medium, and the front and back images are aligned.

[0093] However, it is worth pointing out that mechanical errors (such as printing carriage installation error, stepping error, etc.) are inevitable in actual production, which may cause some slight alignment deviations between the front and back images, such as Fig. 9As shown, there may be an alignment deviation E1 in the X direction (hereinafter referred to as the vertical alignment deviation), or an alignment deviation E2 in the Y direction (hereinafter referred to as the horizontal alignment deviation), or both alignment deviations. In some applications with high precision requirements, even a slight alignment deviation may affect product quality and reduce customer satisfaction.

[0094] After the fourth printing data is processed to obtain the fifth printing data, in order to ensure the accurate alignment of the front and back images in actual printing, the first printing carriage and the second printing carriage are first controlled to print a test image according to the third printing data and the fifth printing data, the alignment of the front and back sides is determined according to the test image, and the third printing data and the fifth printing data are further adjusted according to the alignment. In one embodiment, after obtaining the fifth printing data, the method further includes:

[0095] Control the first printing carriage and the second printing carriage to print a first test image and a second test image on the front and back sides of the printing medium respectively according to the third printing data and the fifth printing data;

[0096] Acquire a vertical alignment deviation between the first test image and the second test image;

[0097] A number of blank data are inserted or deleted at the front end of each line of data in the third printing data and / or the fifth printing data according to the vertical alignment deviation.

[0098] Specifically, the third print data and the fifth print data here can be one of the PASS data or multiple PASS data in the overall print data. The third print data and the fifth print data are used to print a test image to determine whether there is a vertical alignment deviation and its size, and according to the vertical alignment deviation, blank data is inserted or deleted in the third print data or the fifth print data in the actual printing process to make corrections. For example, the printing mode of each side in the double-sided printing is 2PASS printing, and the printing accuracy is 360dpi*360dpi. When starting the double-sided printing, the double-sided printing of 2PASS data is first performed to obtain the first test image 91 and the second test image 92, respectively, as shown in FIG. Fig. 9 As shown in FIG. 1 , assuming that the distance between the first test image 91 on the front side and the left edge of the printing medium (or the left end starting printing position) is 1.2 mm, and the distance between the second test image 92 on the back side and the left edge of the printing medium (or the left end starting printing position) is 1 mm, then the vertical alignment deviation is obtained according to the first test image and the second test image as shown in FIG. Fig. 9As shown in E1, it is 0.2mm. According to the printing accuracy and alignment deviation, the number of blank data to be inserted or deleted is 3. In the subsequent actual printing process, 3 blank data can be deleted at the front end of each line of data in the third printing data to correct the alignment deviation, or 3 blank data can be deleted at the front end of each line of data in the fifth printing data, or 1 blank data can be deleted at the front end of each line of data in the third printing data, and two blank data can be inserted at the front end of each line of data in the fifth printing data; if there is no blank data at the front end of the third printing data and the fifth printing data, the alignment deviation can be corrected by inserting blank data. Exemplarily, assuming that the distance between the first test image 91 on the front side and the left edge of the printing medium (or the left end starting printing position) is 0mm, and the distance between the second test image 92 on the back side and the left edge of the printing medium (or the left end starting printing position) is 0.2mm, the alignment deviation can be corrected by inserting 3 blank data at the front end of the third printing data or inserting 3 blank data at the front end of the fifth printing data.

[0099] In one embodiment, when the number of blank data to be inserted or deleted obtained according to the horizontal alignment deviation is less than 1, the alignment deviation can be corrected by adjusting the ink volume values ​​corresponding to the non-blank data at the beginning and end of each line of data. For example, assuming Fig. 9 The vertical alignment deviation E1 obtained is 0.05. According to the printing accuracy and the vertical alignment deviation, the number of blank data that needs to be inserted or deleted is 0.7. At this time, the ink volume of the non-blank data at the beginning and end of each line of data in the third print data can be adjusted, such as increasing the ink volume of the first non-blank data in each line of data and reducing the ink volume of the last non-blank data to reduce the vertical alignment deviation.

[0100] In one embodiment, if a horizontal alignment deviation is also detected through the first test image and the second test image, after controlling the first printing carriage and the second printing carriage to print the first test image and the second test image on the front and back sides of the printing medium respectively according to the third printing data and the fifth printing data, the method further includes:

[0101] Acquire a horizontal alignment deviation between the first test image and the second test image;

[0102] Insert or delete a number of lines of blank data in the third print data and / or the fifth print data according to the horizontal alignment deviation. Fig. 9As shown, assuming that the detected horizontal alignment deviation E2 of the first test image 91 and the second test image 92 is 0.2 mm, the number of blank data lines that need to be inserted or deleted is 3 lines according to the printing accuracy and the horizontal alignment deviation. Subsequently, in the actual printing process, 3 lines of blank data can be inserted in front of the 0th line of data in the third print data (equivalent to moving the front image up 0.2 mm in the Y direction, or, if the front data in the fifth print data (with the 0th line of data as the front) includes multiple lines of blank data, 3 lines of blank data can be deleted, or correction can be made by inserting 2 lines of blank data before the third print data and deleting 1 line of blank data in the fifth print data.

[0103] In one embodiment, when the number of blank data lines to be inserted or deleted obtained according to the horizontal alignment deviation is less than 1, the modification can be performed by adjusting the ink volume value corresponding to the data. Fig. 9 The horizontal alignment deviation E2 shown is 0.05mm, and the number of blank data rows that need to be adjusted is 0.7 rows. At this time, the amount of ink corresponding to the 0th row of data of the third printing data (corresponding to the bottom of the image) can be reduced, and the amount of ink corresponding to the last row of data of the third printing data (corresponding to the top of the image) can be increased to reduce the horizontal alignment deviation of the front and back images.

[0104] In one embodiment, the print image is centered on both sides of the print medium. At this time, the starting print position of the print image needs to be calculated, that is, the starting print positions of the first print carriage and the second print carriage need to be obtained before printing. Preferably, obtaining the starting print positions of the first print carriage and the second print carriage includes:

[0105] Obtaining a maximum scanning width of the first printing carriage in the main scanning direction, recorded as a first width;

[0106] Acquire the width of the image to be printed in the main scanning direction, recorded as a second width;

[0107] The starting printing positions of the first printing carriage and the second printing carriage are obtained according to the first width and the second width.

[0108] Specifically, the maximum scanning width of the first printing carriage in the main scanning direction X refers to the maximum width of the image that can be printed when the first printing carriage moves along the main scanning direction (also known as the machine width in the industry), which is recorded as the first width. The width of the image to be printed on the printing medium, that is, the width of the image to be printed in the main scanning direction, is obtained, which is recorded as the second width. The starting printing positions of the first printing carriage and the second printing carriage can be calculated based on the first width and the second width. Exemplarily, the first width is 2000mm, the second width is 1000, (2000-1000) / 2=500mm. When printing, the first printing carriage starts from the printing origin at the right end of the beam and moves 500mm from right to left along the main scanning direction before starting inkjet printing. Similarly, the second printing carriage starts from the printing origin at the right end of the beam and moves 500mm from left to right along the main scanning direction before starting inkjet printing. Preferably, the mainboard control system of the lower computer of the inkjet printing device performs automatic centering processing of image printing according to the above calculation method. After the first width and the second width are input, the control system automatically calculates the starting printing positions of the first printing carriage and the second printing carriage according to the above data, and controls the first printing carriage and the second printing carriage to start spraying ink at the starting printing positions to print the image. Fig. 9 The control system automatically calculates the starting printing position 17 of the front image 15 and the starting printing position 18 of the back image 16 according to the first width and the second width, so that the front and back images are printed in the center.

[0109] In actual applications, due to the different materials of the printing media, their absorption or carrying capacity of ink is also different. Because the printing medium needs to be printed on both sides, if the amount of ink sprayed by the printing carriage is too large, the ink on the front and back sides will penetrate into the image on the opposite side, seriously affecting the imaging effect and the final printing quality. In one embodiment, in order to reduce the mutual penetration between the ink on the front and back sides and improve the printing effect on the front and back sides, the ink amount of the printing data is adjusted by determining the preferred value of the ink that the front and back sides of the printing medium can carry or absorb. Preferably, the first printing data is composed of dot data, and before the first printing data is expanded to obtain the second printing data, it also includes:

[0110] Acquire the total ink volume corresponding to the first printing data;

[0111] Determine preferred values ​​of the amount of ink carried by the front side and the back side of the printing medium, respectively, and record them as a first preferred ink amount and a second preferred ink amount;

[0112] The ink volume value corresponding to the dot data is adjusted according to the total ink volume, the first preferred ink volume, and the second preferred ink volume.

[0113] Specifically, the preferred values ​​of the ink volume carried by the front and back sides of the printing medium, i.e., the first preferred ink volume and the second preferred ink volume, can be determined by repeatedly performing inkjet tests to obtain the ink volume when the ink is sprayed onto the front side of the printing medium to form an image and the image effect meets the preset requirements (e.g., the image density, color saturation, etc. of the front side image meet the requirements but no ink penetrates into the back side), and the ink volume at this time is recorded as the first preferred ink volume, and the second preferred ink volume is obtained in the same way. If the front and back sides of the printing medium are made of the same material, generally speaking, the first preferred ink volume and the second preferred ink volume are the same.

[0114] The first printing data is the image dot data after rasterization of the image to be printed. The image dot data is two-dimensional or higher-dimensional tensor data, which is composed of dot data. Each dot data is used to characterize the ink output of the corresponding nozzle. Taking 2-bit screening processing (or rasterization processing) as an example, the dot data includes dot data 00, dot data 01, dot data 10 and dot data 11. For ease of description, the dot data 00 is recorded as empty dot data, the dot data 01 is recorded as small ink dot data, the dot data 10 is recorded as medium ink dot data, and the dot data 11 is recorded as large ink dot data. When printing, the ink volume of large ink dot data, medium ink dot data and small ink dot data is different. For example, the ink volume of large ink dot data is set to 10PL (the first ink volume is 10PL), the ink volume of medium ink dot data is set to 7PL (the second ink volume is 7PL), and the ink volume of small ink dot data is set to 5PL (the third ink volume is 5PL). If a certain print data (dot data) in the first print data is 11, then the corresponding ink dot is a large ink dot, and the ink volume sprayed during printing is 10PL. If a certain print data (dot data) in the first print data is 10, then the corresponding ink dot is a medium ink dot..., the first ink volume, the second ink volume and the third ink volume can be determined according to the actual printing situation, and the above 10PL, 7PL and 5PL are just examples. The total ink volume corresponding to the first print data can be calculated according to the ink volume corresponding to each dot data. The first printing data is the data of one side (front or back) of the printing medium. Based on the total ink amount and the first preferred ink amount and the second preferred ink amount, it can be known whether the amount of ink to be sprayed will be greater than the preferred value of the amount of ink carried or absorbed by the front or back of the printing medium. If so, the amount of ink corresponding to each point data in the first printing data can be adjusted accordingly to ensure that the amount of ink sprayed will not exceed the preferred value of the amount of ink carried by the front or back of the printing medium.

[0115] Preferably, the adjusting the ink volume value corresponding to the dot data according to the total ink volume and the first preferred ink volume and the second preferred ink volume comprises:

[0116] Determine whether a first difference between the total ink volume and the first preferred ink volume is greater than or equal to a preset threshold and / or whether a second difference between the total ink volume and the second preferred ink volume is greater than or equal to the preset threshold;

[0117] If yes, obtaining an ink volume adjustment value according to the first difference and / or the second difference;

[0118] Any one or more of the first ink amount, the second ink amount, and the third ink amount are adjusted according to the ink amount adjustment value.

[0119] Specifically, in one embodiment, if the materials of the front and back sides of the printing medium are the same, and the first preferred ink amount and the second preferred ink amount are the same, then it is only necessary to determine whether the first difference between the first preferred ink amount and the total ink amount or the second difference between the second preferred ink amount and the total ink amount is greater than a preset threshold value, where the preset threshold value can be determined according to the actual application situation. If it exceeds, it may cause the ink on the front and back sides to penetrate each other. At this time, it is necessary to reduce the amount of ink sprayed thereon, and accordingly, it is necessary to adjust the first printing data. Exemplarily, after obtaining the first difference or the second difference, it is possible to know the ink amount adjustment value that needs to reduce the ink amount corresponding to the first printing data, and according to the ink amount adjustment value, any one or more of the ink amount of the large ink dot data (first ink amount), the ink amount of the medium ink dot data (second ink amount) or the ink amount of the small ink dot data (third ink amount) can be adjusted. For example, if the calculated ink volume adjustment value is 100PL, and the first print data consists of 100 large ink dot data, 100 small ink dot data, and 200 small ink dot data, only the ink volume of the 100 large ink dot data can be adjusted, for example, 10PL is adjusted to 9PL, so that the total ink volume corresponding to the first print data will be reduced by 100PL. When the first print data is subsequently expanded to obtain the second print data, and the third print data and the fourth print data are extracted from the second print data (the fifth print data is obtained after data processing) for printing on both sides, the ink volume corresponding to the large ink dot data in the third print data and the fifth print data will also be reduced accordingly, thereby effectively reducing the impact of the mutual penetration of ink on the front and back sides when the ink volume is too large.

[0120] In another embodiment, if the materials corresponding to the front and back sides of the printing medium are different, their first preferred ink volume and second preferred ink volume are different. At this time, it is necessary to compare them with the total ink volume of the first printing data respectively to obtain different first difference values ​​and second difference values, and obtain different ink volume adjustment values ​​for the front and back sides according to the first difference value and the second difference value, assuming that they are the first ink volume adjustment value and the second ink volume adjustment value respectively. Then, when printing the front image, that is, when printing according to the third printing data, the ink volume of the large ink dot data, that is, the first ink volume, the ink volume of the medium ink dot data, that is, the second ink volume, and the ink volume of the small ink dot data, that is, the third ink volume, is adjusted according to the first ink volume adjustment value. When printing the back image, that is, when printing according to the fifth printing data, the ink volume of the large ink dot data, that is, the first ink volume, the ink volume of the medium ink dot data, that is, the second ink volume, and the ink volume of the small ink dot data, that is, the third ink volume, is adjusted according to the second ink volume adjustment value. Any one or more of the inks are adjusted, thereby effectively reducing the impact of the mutual penetration of inks on the front and back sides when the ink volume is too large.

[0121] In summary, the double-sided inkjet printing method provided by the embodiment of the present invention is based on a driving mechanism to drive the first printing carriage and the second printing carriage to move synchronously toward or in the opposite direction at the same printing height to achieve simultaneous printing on the front and back sides of the printing medium. Compared with the existing double-sided inkjet printing technology, it does not need to wait for the ink to dry or perform additional flipping operations, which can significantly shorten the printing time and improve the printing efficiency. When the front and back sides are printed synchronously, the time and position of the ink penetrating into the front and back sides of the printing medium are close, thereby reducing the tension difference between the front and back sides caused by the ink penetrating successively, reducing the influence of the tension difference on the printing effect, and helping to improve the printing quality. The double-sided inkjet printing data processing method provided in the method of the present invention is simple and efficient, can better meet the needs of double-sided printing, improve the printing quality and efficiency, and improve user satisfaction.

[0122] Embodiment 2

[0123] Based on the above embodiment 1, please refer to Fig.10 The embodiment of the present invention provides a double-sided inkjet printing device 200, the device 200 comprising:

[0124] The data acquisition module 201 is used to acquire the image to be printed, and perform rasterization processing on the image to be printed to obtain first printing data;

[0125] A data expansion module 202, configured to expand the first print data to obtain second print data;

[0126] A data extraction module 203, configured to extract third printing data and fourth printing data from the second printing data respectively;

[0127] A data processing module 204, configured to process the fourth printing data to obtain fifth printing data;

[0128] The printing module 205 is used to send the third printing data and the fifth printing data to the first printing carriage and the second printing carriage respectively, drive the first printing carriage and the second printing carriage to move synchronously towards or in the opposite direction at the same printing height, and respectively spray ink onto the front and back sides of the printing medium to form an image.

[0129] Preferably, the first print data includes first black channel data, first cyan channel data, first magenta channel data and first yellow channel data, each having N lines, and the data expansion module 202 includes:

[0130] a copying unit, configured to copy the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data of the i-th line in the first print data respectively, and obtain the second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data of the i-th line;

[0131] an inserting unit, configured to insert the second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data of the i-th line between the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data of the i-th line and the i+1-th line to obtain the second printing data;

[0132] Where i=0,1,2,...N-1.

[0133] Preferably, the data extraction unit comprises:

[0134] a first extraction unit, configured to extract the first black channel data, the first cyan channel data, the first magenta channel data, and the first yellow channel data from the second printing data in sequence according to the number of lines as the third printing data;

[0135] The second extraction unit is used to extract second black channel data, second cyan channel data, second magenta channel data and second yellow channel data corresponding to the number of lines of first black channel data, first cyan channel data, first magenta channel data and first yellow channel data in the third print data from the second print data as the fourth print data.

[0136] Preferably, the data processing module 204 includes:

[0137] A mirror processing unit, used for performing mirror processing on the fourth printing data to obtain mirror printing data;

[0138] A judging unit, used for judging whether the end of each line of data in the mirror printing data contains blank data;

[0139] A first acquiring unit, configured to place the blank data at the front end of each line of data to obtain the fifth printing data;

[0140] The second acquiring unit is used for: if no, the mirror printing data is the fifth printing data.

[0141] Preferably, the device further comprises:

[0142] A first width acquisition module, used to acquire a maximum scanning width of the first printing carriage in a main scanning direction, recorded as a first width;

[0143] A second width acquisition module, used for acquiring the width of the image to be printed in the main scanning direction, recorded as a second width;

[0144] A starting printing position acquisition module is used to acquire the starting printing positions of the first printing carriage and the second printing carriage according to the first width and the second width.

[0145] Preferably, the device further comprises:

[0146] A total ink acquisition module, used for acquiring the total ink volume corresponding to the first printing data;

[0147] Preferred ink amount obtaining ink amount, used to respectively determine preferred values ​​of the amount of ink carried by the front side and the back side of the printing medium, which are recorded as a first preferred ink amount and a second preferred ink amount respectively;

[0148] An adjustment module is used to adjust the ink volume value corresponding to the dot data according to the total ink volume and the first preferred ink volume and the second preferred ink volume.

[0149] Preferably, the dot data includes large ink dot data, medium ink dot data and small ink dot data, and the corresponding ink amounts are recorded as the first ink amount, the second ink amount and the third ink amount respectively, wherein the first ink amount> the second ink amount> the third ink amount, and the adjustment module includes:

[0150] a comparing unit, configured to determine whether a first difference between the total ink volume and the first preferred ink volume is greater than or equal to a preset threshold and / or whether a second difference between the total ink volume and the second preferred ink volume is greater than or equal to the preset threshold;

[0151] an ink volume adjustment value acquiring unit, configured to acquire the ink volume adjustment value according to the first difference and / or the second difference;

[0152] An adjusting unit is used to adjust any one or more of the first ink amount, the second ink amount and the third ink amount according to the ink amount adjustment value.

[0153] In summary, the double-sided inkjet printing device provided by the embodiment of the present invention is based on a driving mechanism to drive the first printing carriage and the second printing carriage to move synchronously toward or in the opposite direction from both ends of the printing medium at the same printing height to achieve simultaneous printing on the front and back sides of the printing medium. Compared with the existing double-sided inkjet printing technology, it does not need to wait for the ink to dry or perform additional flipping operations, which can significantly shorten the printing time and improve the printing efficiency. When the front and back sides are printed synchronously, the time and position of the ink penetrating into the front and back sides of the printing medium are close, thereby reducing the tension difference between the front and back sides caused by the ink penetrating successively, reducing the influence of the tension difference on the printing effect, and helping to improve the printing quality. In addition, the data processing method during printing in the method of the present invention is simple and efficient, which can better meet the needs of double-sided inkjet printing, improve the printing quality and efficiency, and improve user satisfaction.

[0154] Embodiment 3

[0155] In addition, the double-sided inkjet printing method of the embodiment of the present invention can be implemented by a double-sided inkjet printing device. Figure 1 or Figure 2 As shown, the double-sided inkjet printing device includes a first printing carriage and a second printing carriage, the printing medium is vertically arranged between the first printing carriage and the second printing carriage, the first printing carriage and the second printing carriage can reciprocate along the main scanning direction under the drive of the same driving mechanism, the first printing carriage is used to spray ink to the front side of the printing medium to form an image, and the second printing carriage is used to spray ink to the back side of the printing medium to form an image. In addition, the inkjet printing device also includes a host computer that integrates a rasterization processor and printing control software, Fig.11 A schematic diagram of the hardware structure of a double-sided inkjet printing device control system provided by an embodiment of the present invention is shown.

[0156] The double-sided inkjet printing device control system may include a processor 301 and a memory 302 storing computer program instructions.

[0157] Specifically, the processor 301 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiment of the present invention.

[0158] The memory 302 may include a large capacity memory for data or instructions. For example, but not limitation, the memory 302 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 302 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 302 may be inside or outside the data processing device. In a specific embodiment, the memory 302 is a non-volatile solid-state memory. In a specific embodiment, the memory 302 includes a read-only memory (ROM). In appropriate cases, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM) or a flash memory or a combination of two or more of these.

[0159] The processor 301 implements any one of the double-sided inkjet printing methods in the above embodiments by reading and executing computer program instructions stored in the memory 302 .

[0160] In one example, the double-sided inkjet printing device control system may further include a communication interface 303 and a bus 310. Fig.11 As shown, the processor 301, the memory 302, and the communication interface 303 are connected via a bus 310 and communicate with each other.

[0161] The communication interface 303 is mainly used to implement the communication between the modules, devices, units and / or equipment in the embodiment of the present invention.

[0162] Bus 310 includes hardware, software or both, and the parts of the double-sided inkjet printing device control system are coupled to each other. For example, but not limitation, bus 310 may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front-side bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 310 may include one or more buses. Although the embodiment of the present invention describes and shows a specific bus, the present invention considers any suitable bus or interconnection.

[0163] Embodiment 4

[0164] In addition, in combination with the double-sided inkjet printing method in the above embodiment, the embodiment of the present invention can provide a computer-readable storage medium for implementation. The computer-readable storage medium stores computer program instructions; when the computer program instructions are executed by the processor 301, any double-sided inkjet printing method in the above embodiment is implemented.

[0165] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0166] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0167] It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiments, or in a different order from the embodiments, or several steps can be performed simultaneously.

[0168] The above is only a specific implementation of the present invention. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention.

Claims

1. A double-sided inkjet printing method, characterized in that: The method is applied to a double-sided inkjet printing device, wherein the double-sided inkjet printing device comprises a first printing carriage and a second printing carriage, a printing medium is vertically arranged between the first printing carriage and the second printing carriage, the first printing carriage and the second printing carriage can reciprocate along a main scanning direction under the drive of the same driving mechanism, the first printing carriage is used to spray ink onto the front side of the printing medium to form an image, and the second printing carriage is used to spray ink onto the reverse side of the printing medium to form an image, and the method comprises: Acquire an image to be printed, and perform rasterization processing on the image to be printed to obtain first printing data; Expanding the first printing data to obtain second printing data; extracting third printing data and fourth printing data respectively from the second printing data; Processing the fourth printing data to obtain fifth printing data; Sending the third printing data and the fifth printing data to the first printing carriage and the second printing carriage respectively, driving the first printing carriage and the second printing carriage to move synchronously toward or in opposite directions at the same printing height and respectively spraying ink onto the front and back sides of the printing medium to form an image; The step of processing the fourth print data to obtain the fifth print data comprises: Performing mirror processing on the fourth printing data to obtain mirror printing data; Determining whether the end of each line of data in the mirror print data contains blank data; If yes, placing the blank data at the front of each line of data to obtain the fifth printing data; If not, the mirrored printing data is the fifth printing data; After the fourth print data is processed to obtain fifth print data, the method further includes: Control the first printing carriage and the second printing carriage to print a first test image and a second test image on the front and back sides of the printing medium respectively according to the third printing data and the fifth printing data; Acquire a vertical alignment deviation between the first test image and the second test image; inserting or deleting a number of blank data at the front end of each line of data in the third printing data and / or the fifth printing data according to the vertical alignment deviation; When the number of blank data to be inserted or deleted obtained according to the vertical alignment deviation is less than 1, the vertical alignment deviation is corrected by adjusting the ink volume values ​​corresponding to the non-blank data at the beginning and the end of each line of data; and / or: Acquire a horizontal alignment deviation between the first test image and the second test image; inserting or deleting a plurality of lines of blank data in the third printing data and / or the fifth printing data according to the horizontal alignment deviation; When the number of rows of blank data to be inserted or deleted obtained according to the horizontal alignment deviation is less than 1, the horizontal alignment deviation of the front and back images is reduced by adjusting the ink volume value corresponding to the data.

2. The double-sided inkjet printing method according to claim 1, characterized in that: The first print data includes first black channel data, first cyan channel data, first magenta channel data, and first yellow channel data, each having N lines, and the step of expanding the first print data to obtain the second print data includes: Copy the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data of the i-th line in the first print data respectively, and obtain the second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data of the i-th line; Insert the second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data of the i-th line between the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data of the i-th line and the i+1-th line to obtain the second printing data; Where i = 0, 1, 2, ... N-1, and N is a natural number greater than or equal to 1.

3. The double-sided inkjet printing method according to claim 2, characterized in that: The extracting the third printing data and the fourth printing data from the second printing data respectively comprises: extracting the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data from the second printing data in sequence according to the number of lines as the third printing data; The second black channel data, the second cyan channel data, the second magenta channel data and the second yellow channel data which correspond one to one with the number of lines of the first black channel data, the first cyan channel data, the first magenta channel data and the first yellow channel data in the third print data are extracted from the second print data as the fourth print data.

4. The double-sided inkjet printing method according to claim 1, characterized in that: Before sending the third printing data and the fifth printing data to the first printing carriage and the second printing carriage respectively, driving the first printing carriage and the second printing carriage to synchronously move toward each other from both ends of the printing medium at the same printing height and spraying ink onto the front and back sides of the printing medium to form an image, the method further includes: Obtaining a maximum scanning width of the first printing carriage in the main scanning direction, recorded as a first width; Acquire the width of the image to be printed in the main scanning direction, recorded as a second width; The starting printing positions of the first printing carriage and the second printing carriage are obtained according to the first width and the second width.

5. The double-sided inkjet printing method according to claim 1, characterized in that: The first printing data is composed of dot data, and before the first printing data is expanded to obtain the second printing data, the method further includes: Acquire the total ink volume corresponding to the first printing data; Determine preferred values ​​of the amount of ink carried by the front side and the back side of the printing medium, respectively, and record them as a first preferred ink amount and a second preferred ink amount; The ink volume value corresponding to the dot data is adjusted according to the total ink volume, the first preferred ink volume, and the second preferred ink volume.

6. The double-sided inkjet printing method according to claim 5, characterized in that: The dot data includes large ink dot data, medium ink dot data, and small ink dot data, and the corresponding ink amounts are recorded as a first ink amount, a second ink amount, and a third ink amount, respectively, wherein the first ink amount> the second ink amount> the third ink amount, and the adjusting the ink amount value corresponding to the dot data according to the total ink amount and the first preferred ink amount and the second preferred ink amount includes: Determine whether a first difference between the total ink volume and the first preferred ink volume is greater than or equal to a preset threshold and / or whether a second difference between the total ink volume and the second preferred ink volume is greater than or equal to the preset threshold; If yes, obtaining an ink volume adjustment value according to the first difference and / or the second difference; Any one or more of the first ink amount, the second ink amount, and the third ink amount are adjusted according to the ink amount adjustment value.

7. A double-sided inkjet printing device, characterized in that: The device is applied to a double-sided inkjet printing device, wherein the double-sided inkjet printing device comprises a first printing carriage and a second printing carriage, a printing medium is vertically arranged between the first printing carriage and the second printing carriage, the first printing carriage and the second printing carriage can reciprocate along the main scanning direction under the drive of the same driving mechanism, the first printing carriage is used to spray ink onto the front side of the printing medium to form an image, and the second printing carriage is used to spray ink onto the reverse side of the printing medium to form an image, and the device comprises: A data acquisition module, used for acquiring an image to be printed, and performing rasterization processing on the image to be printed to obtain first printing data; A data expansion module, used for expanding the first printing data to obtain second printing data; A data extraction module, used for respectively extracting third printing data and fourth printing data from the second printing data; A data processing module, for performing data processing on the fourth printing data to obtain fifth printing data, including: performing mirror processing on the fourth printing data to obtain mirror printing data; determining whether the end of each line of data in the mirror printing data contains blank data; if so, placing the blank data at the front end of each line of data to obtain the fifth printing data; if not, the mirror printing data is the fifth printing data; after performing data processing on the fourth printing data to obtain the fifth printing data, the module also includes: controlling the first printing carriage and the second printing carriage to print a first test image and a second test image on the front and back sides of the printing medium respectively according to the third printing data and the fifth printing data; obtaining the first test image and the second vertical alignment deviation of the test image; inserting or deleting a number of blank data at the front end of each line of data in the third print data and / or the fifth print data according to the vertical alignment deviation; when the number of blank data to be inserted or deleted obtained according to the vertical alignment deviation is less than 1, correcting the vertical alignment deviation by adjusting the ink volume value corresponding to the non-blank data at the beginning and end of each line of data; and / or: obtaining the horizontal alignment deviation of the first test image and the second test image; inserting or deleting a number of blank data lines in the third print data and / or the fifth print data according to the horizontal alignment deviation; when the number of blank data lines to be inserted or deleted obtained according to the horizontal alignment deviation is less than 1, reducing the horizontal alignment deviation of the front and back images by adjusting the ink volume value corresponding to the data; The printing module is used to send the third printing data and the fifth printing data to the first printing carriage and the second printing carriage respectively, drive the first printing carriage and the second printing carriage to move synchronously towards or in opposite directions at the same printing height, and respectively spray ink onto the front and back sides of the printing medium to form an image.

8. A double-sided inkjet printing device, characterized in that: The double-sided inkjet printing device comprises a first printing carriage and a second printing carriage, the printing medium is vertically arranged between the first printing carriage and the second printing carriage, the first printing carriage and the second printing carriage are driven by the same driving mechanism to reciprocate along the main scanning direction, the first printing carriage is used to spray ink onto the front side of the printing medium to form an image, and the second printing carriage is used to spray ink onto the back side of the printing medium to form an image; The double-sided inkjet printing device further comprises: at least one processor, at least one memory, and computer program instructions stored in the memory, and when the computer program instructions are executed by the processor, the method according to any one of claims 1 to 6 is implemented.

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