Double-sided ink-jet printing method, device and equipment based on ink quantity optimization

Abstract

The invention discloses a double-sided ink-jet printing method, device and equipment based on ink quantity optimization, and relates to the technical field of ink-jet printing. According to the method, a driving mechanism drives a first printing trolley and a second printing trolley to synchronously move oppositely or reversely at the same printing height to achieve simultaneous printing of the front face and the back face of a printing medium, and compared with an existing double-face ink-jet printing technology, it is not needed to wait for drying of ink or conduct additional overturning operation; and when the front and back surfaces are synchronously printed, the time and the position of ink permeating into the front and back surfaces of a printing medium are close, so that the tension difference of the front and back surfaces caused by successive permeation of the ink is reduced, the influence of the tension difference on the printing effect is reduced, and the printing quality is improved. In addition, the data processing mode in the printing process is simple and efficient, the printing ink amount is optimized, the requirement for double-face ink-jet printing can be better met, the printing quality and efficiency are improved, and the user satisfaction degree is improved.

Description

[0001] This application is a divisional application of the invention patent application with the application number 202410502363.9, titled "Double-sided Inkjet Printing Method, Device and Equipment", which was filed on April 25, 2024. Technical Field

[0002] The present invention relates to the technical field of inkjet printing, and in particular, to a double-sided inkjet printing method, device and equipment based on ink volume optimization. Background Art

[0003] In digital inkjet printing applications, double-sided inkjet printing is a technology that forms images by inkjetting on both sides of printing media such as paper, textile fabrics, glass, and acrylic. Usually, traditional inkjet printing devices can only inkjet on one side of the printing media, and the other side needs to wait for the ink to dry before being flipped for printing, which wastes time. In addition, referring to the double-sided printing method disclosed in the patent document with the application publication number "CN109334254A" and the patent title "Double-sided Printing Method and Double-sided Printer", the existing double-sided printing needs to be completed through a complex cloth winding structure and two scanning mechanisms for the front and back sides. That is, first, the front scanning mechanism, i.e., the first printing carriage, is controlled to inkjet and print the front side, and then with the assistance of the cloth winding roller, the back scanning mechanism, i.e., the second printing carriage, can inkjet and print on the back side, thus realizing double-sided printing. This printing method has the following defects: If one side is printed first and the ink penetrates, the side with the penetrated ink will significantly change in terms of tension and quality, resulting in different tensions on both sides of the printing media, which will affect the accuracy of the transmission system or the feeding and discharging system during the transmission on the front and back sides. Moreover, since two scanning mechanisms are used, two positioning mechanisms (such as grating rulers) are required to position the nozzle for ignition. It is difficult to ensure the mechanical rigidity and error consistency of the two positioning mechanisms, which will also cause errors in double-sided image printing and affect the printing quality. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a double-sided inkjet printing method, device and equipment based on ink volume optimization to solve the problems of low efficiency and poor printing quality in existing double-sided inkjet printing.

[0005] In a first aspect, an embodiment of the present invention provides a duplex inkjet printing method based on ink volume optimization. The method is applied to a duplex inkjet printing device, where the duplex 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 eject ink onto the front side of the printing medium to form an image, and the second printing carriage is used to eject ink onto the back side of the printing medium to form an image. The method includes:

[0006] Obtain an image to be printed, and perform rasterization processing on the image to be printed to obtain first printing data;

[0007] Expand the first printing data to obtain second printing data;

[0008] Extract third printing data and fourth printing data from the second printing data respectively;

[0009] Perform data processing on the fourth printing data to obtain fifth printing data;

[0010] 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 in opposite or same directions at the same printing height, and eject ink onto the front and back sides of the printing medium respectively to form an image;

[0011] Among them, the first printing data is composed of dot data. Before expanding the first printing data to obtain second printing data, it further includes: obtaining the total ink volume corresponding to the first printing data; respectively determining the preferred values of the ink volumes borne on the front and back sides of the printing medium, denoted as the first preferred ink volume and the second preferred ink volume respectively; adjusting the ink volume values corresponding to the dot data according to the total ink volume, the first preferred ink volume, and the second preferred ink volume.

[0012] Preferably, the dot data includes large dot data, medium dot data, and small dot data, and the corresponding ink volumes are denoted as the first ink volume, the second ink volume, and the third ink volume respectively, where the first ink volume > the second ink volume > the third ink volume. The adjustment of the ink volume values corresponding to the dot data according to the total ink volume, the first preferred ink volume, and the second preferred ink volume includes:

[0013] Judging 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;

[0014] If so, obtain an ink amount adjustment value according to the first difference and / or the second difference;

[0015] 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.

[0016] Preferably, when the materials on both sides of the printing medium are the same, the first preferred ink amount is the same as the second preferred ink amount; when the materials on both sides of the printing medium are different, the first preferred ink amount is different from the second preferred ink amount.

[0017] 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 rows. The obtaining of the second print data by expanding the first print data includes:

[0018] Copy the first black channel data, first cyan channel data, first magenta channel data, and first yellow channel data of the i-th row in the first print data respectively to obtain second black channel data, second cyan channel data, second magenta channel data, and second yellow channel data of the i-th row;

[0019] Insert the second black channel data, second cyan channel data, second magenta channel data, and second yellow channel data of the i-th row between the first black channel data, first cyan channel data, first magenta channel data, and first yellow channel data of the i-th row and the (i + 1)-th row to obtain the second print data;

[0020] where i = 0, 1, 2,..., N - 1, and N is a natural number greater than or equal to 1.

[0021] Preferably, the extracting of the third print data and the fourth print data from the second print data includes:

[0022] 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 print data row by row as the third print data;

[0023] Extract the second black channel data, the second cyan channel data, the second magenta channel data, and the second yellow channel data corresponding one by one to the rows 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 from the second print data as the fourth print data.

[0024] Preferably, the data processing of the fourth print data to obtain the fifth print data includes:

[0025] Mirror process the fourth printing data to obtain mirrored printing data;

[0026] Determine whether the end of each line of data in the mirrored printing data contains blank data;

[0027] If so, place the blank data at the front of each line of data to obtain the fifth printing data;

[0028] If not, the mirrored printing data is the fifth printing data.

[0029] Preferably, after obtaining the fifth printing data by processing the fourth printing data, the following steps are further included:

[0030] 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;

[0031] Obtain the vertical alignment deviation between the first test image and the second test image;

[0032] Insert or delete a certain number of blank data at the front of each line of data in the third printing data and / or the fifth printing data according to the vertical alignment deviation;

[0033] And / or:

[0034] Obtain the horizontal alignment deviation between the first test image and the second test image;

[0035] Insert or delete a certain number of lines of blank data in the third printing data and / or the fifth printing data according to the horizontal alignment deviation.

[0036] 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 move synchronously and towards each other from both ends of the printing medium at the same printing height and ejecting ink onto the front and back sides of the printing medium to form an image, the following steps are further included:

[0037] Obtain the maximum scanning width of the first printing carriage in the main scanning direction, denoted as the first width;

[0038] Obtain the width of the image to be printed in the main scanning direction, denoted as the second width;

[0039] Obtain the starting printing positions of the first printing carriage and the second printing carriage according to the first width and the second width.

[0040] Second aspect, an embodiment of the present invention provides a double-sided inkjet printing device based on ink volume optimization, which is applied to a double-sided inkjet printing device. 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, and 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 eject ink onto the front side of the printing medium to form an image, and the second printing carriage is used to eject ink onto the back side of the printing medium to form an image. The device includes:

[0041] A data acquisition module, configured to acquire an image to be printed, and perform rasterization processing on the image to be printed to obtain first printing data;

[0042] A data expansion module, configured to expand the first printing data to obtain second printing data;

[0043] A data extraction module, configured to respectively extract third printing data and fourth printing data from the second printing data;

[0044] A data processing module, configured to perform data processing on the fourth printing data to obtain fifth printing data;

[0045] A printing module, configured to respectively send the third printing data and the fifth printing data to the first printing carriage and the second printing carriage, drive the first printing carriage and the second printing carriage to move synchronously towards or away from each other at the same printing height, and respectively eject ink onto the front and back sides of the printing medium to form an image;

[0046] A total module acquisition module, configured to acquire the total ink volume corresponding to the first printing data, wherein the first printing data is composed of dot data;

[0047] A preferred ink volume acquisition module, configured to respectively determine the preferred values of the ink volumes borne on the front and back sides of the printing medium, denoted as a first preferred ink volume and a second preferred ink volume respectively;

[0048] An adjustment module, configured to adjust the ink volume values corresponding to the dot data according to the total ink volume, the first preferred ink volume, and the second preferred ink volume.

[0049] In a third aspect, an embodiment of the present invention provides a duplex inkjet printing device based on ink volume optimization. The duplex 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 drive mechanism. The first printing carriage is used to eject ink onto the front side of the printing medium to form an image, and the second printing carriage is used to eject ink onto the back side of the printing medium to form an image. The duplex inkjet printing device further includes: at least one processor, at least one memory, and computer program instructions stored in the memory. When the computer program instructions are executed by the processor, the method of the first aspect in the above-mentioned embodiment is implemented.

[0050] In a fourth aspect, an embodiment of the present invention provides a storage medium, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the method of the first aspect in the above-mentioned embodiment is implemented.

[0051] In summary, the beneficial effects of the present invention are as follows:

[0052] The duplex inkjet printing method, device and equipment based on ink volume optimization provided by the embodiments of the present invention realize simultaneous printing on both sides of a printing medium by driving a first printing carriage and a second printing carriage to move synchronously in opposite or the same direction at the same printing height under the drive of one drive mechanism. Compared with the existing duplex 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. Moreover, when printing on both sides synchronously, the time and position of the ink penetrating into both 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 impact of the tension difference on the printing effect, which is beneficial to improving the printing quality. In addition, the data processing method during printing in the method of the present invention is simple and efficient, and the printing ink volume is optimized, which can better meet the requirements of duplex inkjet printing, improve the printing quality and efficiency, and enhance user satisfaction. Description of the Drawings

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly introduced below. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings, and all of them are within the protection scope of the present invention.

[0054] Figure 1 It is a schematic structural diagram of the duplex inkjet printing device in the embodiment of the present invention.

[0055] Figure 2 It is a schematic diagram of the placement of the printing medium in the embodiment of the present invention.

[0056] Figure 3 It is a schematic flowchart of the double-sided inkjet printing method in an embodiment of the present invention.

[0057] Figure 4 It is a schematic diagram of the first printing data in an embodiment of the present invention.

[0058] Figure 5 It is a schematic diagram of the second printing data in an embodiment of the present invention.

[0059] Figure 6 It is a schematic diagram of the misalignment of the front and back images in an embodiment of the present invention.

[0060] Figure 7 It is a schematic diagram of data processing in an embodiment of the present invention.

[0061] Figure 8a It is a schematic diagram of the alignment of the front and back images in an embodiment of the present invention.

[0062] Figure 8b It is a schematic diagram of the alignment deviation in an embodiment of the present invention.

[0063] Figure 9 It is a schematic diagram of centered printing in an embodiment of the present invention.

[0064] Figure 10 It is a schematic structural diagram of the double-sided inkjet printing device in an embodiment of the present invention.

[0065] Figure 11 It is a schematic structural diagram of the control system of the double-sided inkjet printing equipment in an embodiment of the present invention. Detailed implementation manners

[0066] Next, the features and exemplary embodiments of various aspects of the present invention will be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. 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 some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention.

[0067] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0068] Embodiment 1

[0069] An embodiment of the present invention provides a double-sided inkjet printing device, such as Figure 1 shown. The double-sided inkjet printing device includes a first printing carriage 5, a second printing carriage 6, and a cross beam 4. A timing belt 3, a driving wheel 1, and a driven wheel 2 are arranged in the cross beam 4. A driving mechanism (not shown) drives the driving wheel 1 to rotate and drives the driven wheel 2 to rotate through the timing belt 3 at the same time. The first printing carriage 5 and the second printing carriage 6 are both mounted on the timing belt 3 of the cross beam 4 and are respectively arranged on both sides of the cross beam 4. For example, the first printing carriage 5 is mounted on the front side 41, and the second printing carriage 6 is mounted on the rear side 42. The timing belt 3 can drive the first printing carriage 5 to reciprocate along the main scanning direction X (also known as the printing direction) on the front side 41 and the second printing carriage 6 to reciprocate along the main scanning direction X on the rear side 42. The double-sided inkjet printing system provided by the embodiment of the present invention does not require a double cross beam, a double control system, or a double driving structure, and can effectively reduce costs, enabling high-quality double-sided inkjet printing effects even in low-cost machine types and control systems.

[0070] Such as Figure 2As shown in the figure, when double-sided printing is required, the printing medium 8 passes through the cross beam 4 and the synchronous belt 3 and is vertically arranged (perpendicular to the horizontal plane) 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 set at both ends of the cross beam 4. For example, the printing origin of the first printing carriage 5 is set at the right end 43 of the cross beam 4, and the printing origin of the second printing carriage is set at the left end 44 of the cross beam 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, the second printing carriage 6 is driven to move synchronously from left to right at the same time. Since the first printing carriage 5 and the second printing carriage 6 are arranged on the same cross beam, their printing heights relative to the printing medium are the same. In this way, inkjet printing is performed on both the front and back sides at the same height position of the printing medium at the same time, and the time and position of the ink penetrating into both 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 impact 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 of the back side, which greatly reduces the development cost and trial-and-error cost, helps users quickly switch from single-sided printing to double-sided printing, minimizes the development cycle and trial-and-error cost, and brings the economic benefits of rapid iteration to users faster.

[0071] Based on the above double-sided inkjet printing device, please refer to 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:

[0072] S1: Obtain the image to be printed, and perform rasterization processing on the image to be printed to obtain the first printing data;

[0073] S2: Expand the first printing data to obtain the second printing data;

[0074] S3: Respectively extract the third printing data and the fourth printing data from the second printing data;

[0075] S4: Perform data processing on the fourth printing data to obtain the fifth printing data;

[0076] 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 in opposite directions or in the same direction at the same printing height, and respectively spray ink onto the front and back sides of the printing medium to form an image.

[0077] In an embodiment of the present invention, taking the printing of a double-sided image with the same and mirror-image front and back sides on a printing medium as an example, it is described how to control the double-sided inkjet printing device to perform double-sided printing. Specifically, first, the image to be printed is obtained. Here, the image to be printed can be a bitmap or a vector graph. The image to be printed is input into an 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 to obtain printing data in the PRN format that can be recognized by the double-sided inkjet printing device, denoted as the first printing data. Since double-sided printing is required and the first printing data is only sufficient for printing one side, the first printing data needs to be expanded to obtain printing data sufficient for double-sided printing. After expanding the first printing data, the second printing data for double-sided printing is obtained. When printing, the second printing data needs to be split while printing. The third printing data for printing the front side in the second printing data is extracted and distributed to the first printing carriage, and the fourth printing data for printing the back side is extracted and distributed to the second printing carriage. Since the back-side image and the front-side image are mirror-corresponding, before sending the fourth printing data to the second printing carriage, data processing is performed on it to obtain the fifth printing data, so that the image can be correctly printed on the back side of the printing medium. In addition, in order to reduce the influence of the tension difference on the printing effect, in the embodiment of the present invention, before printing, the first printing carriage and the second printing carriage are respectively set at both ends of the printing medium, such as Figure 2As shown in the figure, 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 receiving the third printing data, the first printing carriage starts inkjet printing from the printing starting point on the front side of the right end of the printing medium. Similarly, after receiving the fifth printing data, the second printing carriage starts inkjet printing from the printing starting point on the back side of the left end of the printing medium. Since both the first printing carriage and the second printing carriage are installed on the same synchronous belt, when driving the first printing carriage to move (scan) from right to left on the front side of the crossbeam for one PASS printing on the front side of the printing medium, it will synchronously drive the second printing carriage to move (scan) from left to right on the back side of the crossbeam for one PASS printing on the back side of the printing medium. After completing one PASS printing, after controlling the printing medium to move a certain distance relative to the crossbeam along the sub-scanning direction Y (or the stepping direction), the first printing carriage is again controlled to move from left to right on the front side of the crossbeam for the next PASS printing on the front side of the printing medium, and similarly drives the second printing carriage to move from right to left on the back side of the crossbeam for the next PASS printing on the back side of the printing medium... Control the first printing carriage and the second printing carriage to move back and forth and scan like this until the image printing on both the front and back sides is completed. In each PASS printing, the printing area heights on both the front and back sides are the same, and the time and position for the ink to penetrate into both 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 being beneficial to improving the printing quality.

[0078] In one embodiment, the image to be printed is a color image. Color images are often printed using C (cyan), M (magenta), Y (yellow), and K (black) inks. The first printing data obtained after rasterizing the image to be printed includes the first black channel data, the first cyan channel data, the first magenta channel data, and the first yellow channel data. As Figure 4 shown is an example of the data format of the first printing data: the file header plus the data of each color channel for each row. Each row of color channel data corresponds to the ink dot data of the corresponding pixels in each pixel row of the printed image. For example, the first black channel data in the 0th row corresponds to the black ink dot data of the 0th row of pixels in the front image, and the first cyan channel data in the 0th row corresponds to the cyan ink dot data of the 0th row of pixels in the front image... The black, cyan, magenta, and yellow ink dots form a color image macroscopically.

[0079] In the implementation of the present invention, the printed images on both the front and back sides are the same and are mirror images. Preferably, the expansion of the first printing data to obtain the second printing data includes:

[0080] 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 row in the first print data 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 i-th row;

[0081] 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 row 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 row and the (i + 1)-th row to obtain the second print data;

[0082] where i = 0, 1, 2, …… N - 1, and N is a natural number greater than or equal to 1.

[0083] Specifically, as Figure 5 shown, copy the first black channel data, the first cyan channel data, the first magenta channel data, and the first yellow channel data of the 0-th row, the 1-st row, …… the (N - 1)-th row 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 rows, and 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 row 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 row and the (i + 1)-th row, and finally obtain the expanded second print data.

[0084] According to the second print data, printing of front and back images can be performed. When performing printing, it is necessary to split the second print data while printing, extract the third print data for printing the front side from the second print data and distribute it to the first printing carriage, and extract the fourth print data for printing the back side and distribute it to the second printing carriage. Preferably, the extracting the third print data and the fourth print data from the second print data respectively includes:

[0085] 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 print data row by row as the third print data;

[0086] Extract the second black channel data, the second cyan channel data, the second magenta channel data, and the second yellow channel data corresponding to the rows 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 from the second print data as the fourth print data.

[0087] Specifically, during printing, the control software of the double-sided inkjet printing device extracts the data of the corresponding number of rows from the second printing data according to the amount of data printed per PASS and sends it to the printing carriage. Suppose one PASS of printing data includes 1 row of data for each color channel. Then, from the second printing data, the first black channel data, the first cyan channel data, the first magenta channel data, and the first yellow channel data of the first row (denoted as 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 row, that is, the 0th row (denoted as the fourth printing data), will be extracted 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 row (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 row, that is, the 1st row (the fourth printing data), will be extracted and sent to the second printing carriage.

[0088] Since the reverse image and the front image are mirror-corresponding, data processing is performed on the fourth printing data to obtain the fifth printing data before sending it to the second printing carriage. Preferably, the data processing of the fourth printing data to obtain the fifth printing data includes:

[0089] Performing mirror processing on the fourth printing data to obtain mirror printing data;

[0090] Determining whether the end of each row of data in the mirror printing data contains blank data;

[0091] If so, placing the blank data at the front of each row of data to obtain the fifth printing data;

[0092] If not, the mirror printing data is the fifth printing data.

[0093] Specifically, before data processing, the fourth printing data and the third printing data are the same. Since mirror printing of the double-sided image needs to be achieved, mirror processing is required for the fourth printing data, and the data processing is generally performed in the printing control software of the host computer of the double-sided inkjet printing device. There may be blank data at the end of each row of color channel data in the third printing data and the fourth printing data. The blank data does not drive the nozzle to eject ink. When the printing control software performs mirror processing on the fourth printing data, it does not perform mirror processing on the blank data, but performs mirror processing on the non-blank data of each row and then sets the blank data at the end of the non-blank data. This processing will result in the image printing result as Figure 6As shown in the figure, assume that the printing starting point is at 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. Due to the blank data at the end, there are some blank pixels 13 (blank image) at the left edge. After mirror processing the fourth printing data, the blank data is still set at the end of each line of data. When printing the reverse image, the starting printing position 10 of the reverse 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 reverse image, resulting in the inability to align the front and back images. If the printing medium is a transparent material, this misalignment will greatly affect the double-sided printing effect. Exemplarily, assume that the width of the rasterized image is 6434 pixels, the number of bytes corresponding to each line of color channel data is 1612 bytes, and variable dot printing (2-bit screening, large, medium, and small ink dots can be used during printing) is used. Then 1 pixel requires 2 bits (2-bit) to represent, so 1 byte (8-bit) can represent 4 pixels. The number of pixels that can be stored in the bytes corresponding to each line of color channel data is 1612 * 4 = 6448 pixels, that is, there are 6448 - 6434 = 14 blank pixels. Since 1 pixel occupies 2 bits, there are 14 * 2 = 28 bits of data as blank data. If the printing accuracy is 360 dpi, 14 / 360 * 25.4 = 0.988 mm, that is, the alignment error between the front and back of the image is nearly 1 mm.

[0094] To ensure the image printing quality, preferably, it is determined whether the end of each line of data in the fourth printing data after mirror processing contains blank data. If so, the blank data needs to be moved to the front of each line of data. After such data processing, the fifth printing data is obtained. Exemplarily, the fourth printing data is as Figure 7 shown. There is blank data 0 in the last byte, the Kth byte. In actual situations, the blank data in the mirror printing data after mirror processing is still at the end, that is, the Kth byte. At this time, the blank data needs to be moved to the front of this line of data to obtain the final fifth printing data. After data processing, the front and back images are as Figure 8a shown. The blank pixels 13 of the front image 12 and the blank pixels 14 of the reverse image 12 are both at the left edge of the printing medium, and the front and back images are aligned.

[0095] However, it should be pointed out that mechanical errors (such as printing carriage installation errors, stepping errors, etc.) that exist in actual production are inevitable and may cause some slight alignment deviations between the front and back images, such as Figure 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. In some applications with high precision requirements, even a slight alignment deviation may affect product quality and lead to a decrease in customer satisfaction.

[0096] After obtaining the fifth printing data by processing the fourth printing data, in order to ensure the precise alignment of the front and back images in actual printing, first control the first printing carriage and the second printing carriage to print test images according to the third printing data and the fifth printing data, determine the alignment of the front and back sides based on the test images, and further adjust the third printing data and the fifth printing data according to the alignment. In one embodiment, after obtaining the fifth printing data, it further includes:

[0097] 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;

[0098] Obtaining the vertical alignment deviation between the first test image and the second test image;

[0099] Inserting or deleting a number of blank data at the front end of each row of data in the third printing data and / or the fifth printing data according to the vertical alignment deviation.

[0100] Specifically, the third printing data and the fifth printing data here can be one PASS data or multiple PASS data in the overall printing data. Use the third printing data and the fifth printing data to print a test image once to determine whether there is a vertical alignment deviation and its magnitude, and insert or delete blank data in the third printing data or the fifth printing data during the actual printing process according to the vertical alignment deviation for correction. For example, in double-sided printing, the printing mode for each side is 2PASS printing, and the printing precision is 360dpi*360dpi. When starting double-sided printing, first perform double-sided printing of 2PASS data to obtain a first test image 91 and a second test image 92 respectively. As Figure 9 shown, assume that the distance between the first test image 91 on the front side and the left edge of the printing medium (or the starting printing position at the left end) is 1.2mm, and the distance between the second test image 92 on the back side and the left edge of the printing medium (or the starting printing position at the left end) is 1mm. Then obtain the vertical alignment deviation based on the first test image and the second test image as Figure 9As shown in E1 of, it is 0.2 mm. According to the printing precision and alignment deviation, the number of blank data to be inserted or deleted is 3. Subsequently, during the actual printing process, 3 blank data can be deleted from 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 from the front end of each line of data in the fifth printing data, or 1 blank data can be deleted from the front end of each line of data in the third printing data and 2 blank data from the front end of each line of data in the fifth printing data; if there are no blank data at the front ends of the third printing data and the fifth printing data, the alignment deviation can be corrected by inserting blank data. Exemplarily, assume that the distance between the first test image 91 on the front side and the left edge of the printing medium (or the starting printing position at the left end) is 0 mm, and the distance between the second test image 92 on the back side and the left edge of the printing medium (or the starting printing position at the left end) is 0.2 mm. 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.

[0101] 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 amount values corresponding to the non-empty data at the head and tail of each line of data. Exemplarily, Figure 9 The vertical alignment deviation E1 obtained is 0.05. According to the printing precision and the vertical alignment deviation, the number of blank data to be inserted or deleted is 0.7. At this time, the ink amount of the non-blank data at the head and tail positions of each line of data in the third printing data can be adjusted, such as increasing the ink amount of the first non-blank data in each line of data and decreasing the ink amount of the last non-blank data, to reduce the vertical alignment deviation.

[0102] 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, it further includes:

[0103] Obtain the horizontal alignment deviation between the first test image and the second test image;

[0104] Insert or delete several lines of blank data in the third printing data and / or the fifth printing data according to the horizontal alignment deviation. Exemplarily, Figure 9As shown, assuming that the horizontal alignment deviation E2 between the first test image 91 and the second test image 92 is detected to be 0.2 mm, the number of blank data rows to be inserted or deleted is 3 rows according to the printing precision and the horizontal alignment deviation. Subsequently, during the actual printing process, 3 rows of blank data can be inserted in front of the data in the 0th row of the third printing data (equivalent to moving the front image up by 0.2 mm in the Y direction), or if there are multiple blank data rows among the previous data (with the 0th row data as the front) in the fifth printing data, 3 rows of blank data can also be deleted. Or it can be corrected by inserting 2 rows of blank data in front of the third printing data and deleting 1 row of blank data in the fifth printing data.

[0105] In one embodiment, when the number of blank data rows to be inserted or deleted obtained according to the horizontal alignment deviation is less than 1, it can be modified by adjusting the ink amount value corresponding to the data. Exemplarily, when the horizontal alignment deviation E2 is 0.05 mm as shown in Figure 9 and the number of blank data rows to be adjusted is 0.7 rows, the ink amount corresponding to the data in the 0th row of the third printing data (corresponding to below the image) can be reduced, while the ink amount corresponding to the last row of the third printing data (corresponding to above the image) can be increased to reduce the horizontal alignment deviation between the front and back images.

[0106] In one embodiment, when the printing images on both sides of the printing medium are centered, it is necessary to calculate the starting printing position of the printing images, that is, the starting printing positions of the first printing carriage and the second printing carriage need to be obtained before printing. Preferably, obtaining the starting printing positions of the first printing carriage and the second printing carriage includes:

[0107] Obtaining the maximum scanning width of the first printing carriage in the main scanning direction, denoted as the first width;

[0108] Obtaining the width of the image to be printed in the main scanning direction, denoted as the second width;

[0109] Obtaining the starting printing positions of the first printing carriage and the second printing carriage according to the first width and the second width.

[0110] 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 in the main scanning direction (also known as the machine width in the industry), denoted 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 denoted as the second width. According to the first width and the second width, the starting printing positions of the first printing carriage and the second printing carriage can be calculated. Exemplarily, the first width is 2000 mm, the second width is 1000, (2000 - 1000) / 2 = 500 mm. When printing, the first printing carriage starts from the printing origin at the right end of the crossbeam and moves 500 mm from right to left in the main scanning direction and then starts inkjet printing. Similarly, the second printing carriage starts from the printing origin at the right end of the crossbeam and moves 500 mm from left to right in the main scanning direction and then starts inkjet printing. Preferably, the main board 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 inputting the first width and the second width, 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 jetting ink at the starting printing positions for image printing. As Figure 9 shown, it is an exemplary diagram of automatic centering printing in an embodiment of the present invention. 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 centered and printed.

[0111] In practical applications, due to the different materials of the printing medium, its absorption or bearing capacity for ink is also different. Since both sides of the printing medium need to be printed, if the amount of ink jetted by the printing carriage is too large, the ink on both sides will penetrate into the opposite image, seriously affecting the imaging effect and the final printing quality. In one embodiment, in order to reduce the mutual penetration effect between the ink on both sides and improve the printing effect on both sides, the ink amount of the printing data is adjusted by determining the preferred values of the ink that can be borne or absorbed by both sides of the printing medium. Preferably, the first printing data is composed of dot data. Before expanding the first printing data to obtain the second printing data, it further includes:

[0112] Obtaining the total ink amount corresponding to the first printing data;

[0113] Respectively determining the preferred values of the ink borne by the front and back sides of the printing medium, denoted as the first preferred ink amount and the second preferred ink amount respectively;

[0114] Adjusting the ink amount values corresponding to the dot data according to the total ink amount, the first preferred ink amount, and the second preferred ink amount.

[0115] Specifically, the preferred values of the ink amounts carried on the front and back sides of the printing medium, namely the first preferred ink amount and the second preferred ink amount, can be determined in the following manner: By repeatedly performing inkjet tests, when the ink is ejected onto the front side of the printing medium to form an image and the image effect meets the preset requirements (such as the image density, color saturation, etc. of the front image meet the requirements but there is no ink penetration to the back side), the ink amount at this time is recorded as the first preferred ink amount. The second preferred ink amount is obtained in the same way. When the materials of the front and back sides of the printing medium are the same, generally, the first preferred ink amount and the second preferred ink amount are the same.

[0116] The first printing data is the image dot matrix data after rasterizing the image to be printed. The image dot matrix data is a two-dimensional or higher-dimensional tensor data, which is composed of dot data. Each dot data is used to characterize the ink output amount of the corresponding nozzle. Taking 2-bit screening (or rasterizing) as an example, the dot data includes dot data 00, dot data 01, dot data 10, and dot data 11. For the convenience of description, the dot data 00 is denoted as the empty dot data, the dot data 01 is denoted as the small ink dot data, the dot data 10 is denoted as the medium ink dot data, and the dot data 11 is denoted as the large ink dot data. During printing, the ink amounts of the large ink dot data, the medium ink dot data, and the small ink dot data are different. Exemplarily, it is set that the ink amount of the large ink dot data is 10 pL (the first ink amount is 10 pL), the ink amount of the medium ink dot data is 7 pL (the second ink amount is 7 pL), and the ink amount of the small ink dot data is 5 pL (the third ink amount is 5 pL). If a certain printing data (dot data) in the first printing data is 11, then the corresponding ink dot is a large ink dot, and the ink amount ejected during inkjet printing is 10 pL. If a certain printing data (dot data) in the first printing data is 10, then the corresponding ink dot is a medium ink dot... The first ink amount, the second ink amount, and the third ink amount can be determined according to the actual printing situation. The above 10 pL, 7 pL, and 5 pL are only examples. According to the ink amounts corresponding to each dot data, the total ink amount corresponding to the first printing data can be calculated. The first printing data is the data of one side (front or back) of the printing medium. According to this total ink amount and the first preferred ink amount and the second preferred ink amount, it can be known whether the ink amount to be ejected will be greater than the preferred value of the ink amount carried or absorbed by the front or back side of the printing medium. If so, the ink amounts corresponding to each dot data in the first printing data can be adjusted accordingly to ensure that the ejected ink amount does not exceed the preferred value of the ink amount carried by the front or back side of the printing medium.

[0117] Preferably, the adjustment of the ink amount value corresponding to the dot data according to the total ink amount, the first preferred ink amount, and the second preferred ink amount includes:

[0118] Judging whether the first difference between the total ink amount and the first preferred ink amount is greater than or equal to a preset threshold and / or whether the second difference between the total ink amount and the second preferred ink amount is greater than or equal to the preset threshold;

[0119] If so, obtain an ink amount adjustment value according to the first difference and / or the second difference;

[0120] 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.

[0121] Specifically, in one embodiment, if the materials on both sides of the front of the printing medium are the same and its first preferred ink amount and 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, and the preset threshold here can be determined according to the actual application situation. If it exceeds, it may cause the ink on both sides to penetrate each other and affect, and at this time, it is necessary to reduce the ink amount of the ink ejected onto it, and correspondingly, it is also necessary to adjust the first printing data. Exemplarily, after obtaining the first difference or the second difference, it can be known the ink amount adjustment value that needs to reduce the ink amount corresponding to the first printing data. According to the ink amount adjustment value, any one or more of the ink amount of the large ink dot data (the first ink amount), the ink amount of the medium ink dot data (the second ink amount), or the ink amount of the small ink dot data (the third ink amount) can be adjusted. Exemplarily, if the calculated ink amount adjustment value is 100 pL, and the first printing data consists of 100 large ink dot data, 100 small ink dot data, and 200 small ink dot data, only the ink amount of 100 large ink dot data can be adjusted. For example, adjust from 10 pL to 9 pL, so that the total ink amount corresponding to the first printing data will be reduced by 100 pL. When the first printing data is subsequently expanded to obtain the second printing data, and the third printing data and the fourth printing data (the fifth printing data is obtained after data processing) are extracted from the second printing data for double-sided printing, the ink amount corresponding to the large ink dot data in the third printing data and the fifth printing data will also be reduced accordingly, thereby effectively reducing the influence of ink penetration between the two sides when the ink amount is too large.

[0122] In another embodiment, if the materials corresponding to the front and back sides of the printing medium are different, and their first preferred ink amount and second preferred ink amount are different, then it is necessary to compare them with the total ink amount of the first printing data respectively to obtain different first and second differences, and obtain different ink amount adjustment values for the front and back sides according to the first and second differences. Let them be the first ink amount adjustment value and the second ink amount adjustment value respectively. Then, when printing the front image, that is, when printing according to the third printing data, adjust the ink amount of any one or more of the large dot data (i.e., the first ink amount), the medium dot data (i.e., the second ink amount), and the small dot data (i.e., the third ink amount) according to the first ink amount adjustment value. When printing the back image, that is, when printing according to the fifth printing data, adjust the ink amount of any one or more of the large dot data (i.e., the first ink amount), the medium dot data (i.e., the second ink amount), and the small dot data (i.e., the third ink amount) according to the second ink amount adjustment value, so as to effectively reduce the influence of ink penetration between the front and back sides when the ink amount is too large.

[0123] 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 in opposite directions or in the same direction at the same printing height to simultaneously print 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, improve the printing efficiency, and the time and position of the ink penetrating into the front and back sides of the printing medium are close when printing the front and back sides synchronously, thus 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, which is beneficial to improving 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, improves the printing quality and efficiency, and improves user satisfaction.

[0124] Embodiment 2

[0125] Based on the above Embodiment 1, please refer to Figure 10 , the embodiment of the present invention provides a double-sided inkjet printing device 200, and the device 200 includes:

[0126] A data acquisition module 201, configured to acquire an image to be printed, and perform rasterization processing on the image to be printed to obtain first printing data;

[0127] A data expansion module 202, configured to expand the first printing data to obtain second printing data;

[0128] A data extraction module 203, configured to respectively extract third printing data and fourth printing data from the second printing data;

[0129] The data processing module 204 is configured to process the fourth print data to obtain the fifth print data;

[0130] The printing module 205 is configured to separately send the third print data and the fifth print data to the first printing carriage and the second printing carriage, drive the first printing carriage and the second printing carriage to move synchronously in opposite directions or in the same direction at the same printing height, and respectively eject ink onto the front and back sides of the printing medium to form an image.

[0131] 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 rows, and the data expansion module 202 includes:

[0132] 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 row in the first print data 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 i-th row;

[0133] 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 row 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 row and the (i + 1)-th row to obtain the second print data;

[0134] where i = 0, 1, 2,..., N - 1.

[0135] Preferably, the data extraction unit includes:

[0136] A first extraction unit configured to sequentially 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 print data by row number as the third print data;

[0137] A second extraction unit configured to extract the second black channel data, the second cyan channel data, the second magenta channel data, and the second yellow channel data corresponding to the row numbers 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 from the second print data as the fourth print data.

[0138] Preferably, the data processing module 204 includes:

[0139] A mirror processing unit configured to perform mirror processing on the fourth print data to obtain mirror print data;

[0140] A judgment unit, configured to judge whether blank data is included at the end of each line of the mirror printing data;

[0141] A first obtaining unit, configured to, if so, place the blank data at the front end of each line of data to obtain the fifth printing data;

[0142] A second obtaining unit, configured to, if not, the mirror printing data is the fifth printing data.

[0143] Preferably, the device further includes:

[0144] A first width obtaining module, configured to obtain the maximum scanning width of the first printing carriage in the main scanning direction, denoted as the first width;

[0145] A second width obtaining module, configured to obtain the width of the image to be printed in the main scanning direction, denoted as the second width;

[0146] A starting printing position obtaining module, configured to obtain the starting printing positions of the first printing carriage and the second printing carriage according to the first width and the second width.

[0147] Preferably, the device further includes:

[0148] A total module obtaining module, configured to obtain the total ink amount corresponding to the first printing data;

[0149] A preferred ink amount obtaining module, configured to respectively determine the preferred values of the ink amounts borne by the front and back sides of the printing medium, denoted as the first preferred ink amount and the second preferred ink amount respectively;

[0150] An adjustment module, configured to adjust the ink amount values corresponding to the dot data according to the total ink amount, the first preferred ink amount, and the second preferred ink amount.

[0151] Preferably, the dot data includes large dot data, medium dot data, and small dot data, and the ink amounts corresponding to them are denoted as the first ink amount, the second ink amount, and the third ink amount respectively, where the first ink amount > the second ink amount > the third ink amount, and the adjustment module includes:

[0152] A comparison unit, configured to judge whether a first difference between the total ink amount and the first preferred ink amount is greater than or equal to a preset threshold and / or whether a second difference between the total ink amount and the second preferred ink amount is greater than or equal to the preset threshold;

[0153] An ink amount adjustment value obtaining unit, configured to, if so, obtain an ink amount adjustment value according to the first difference and / or the second difference;

[0154] An adjustment unit for adjusting 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.

[0155] In summary, the duplex inkjet printing device provided by the embodiment of the present invention drives the first printing carriage and the second printing carriage to move synchronously in opposite directions or in the same direction from both ends of the printing medium at the same printing height based on a single driving mechanism to simultaneously print both sides of the printing medium. Compared with the existing duplex 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, improve the printing efficiency, and when printing both sides synchronously, the time and position of the ink penetrating into both sides of the printing medium are close, thereby reducing the tension difference between the front and back sides caused by the sequential penetration of the ink, reducing the impact of the tension difference on the printing effect, and being beneficial to improving the printing quality. In addition, the data processing method during printing in the method of the present invention is simple and efficient, can better meet the requirements of duplex inkjet printing, improves the printing quality and efficiency, and enhances user satisfaction.

[0156] Embodiment III

[0157] In addition, the duplex inkjet printing method of the embodiment of the present invention can be implemented by a duplex inkjet printing device. Such as Figure 1 or as Figure 2 shown, the duplex 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 eject ink onto the front side of the printing medium to form an image, and the second printing carriage is used to eject ink onto the back side of the printing medium to form an image. In addition, the inkjet printing device further includes a host computer integrated with a rasterization processor and printing control software. Figure 11 Shows a schematic diagram of the hardware structure of the control system of the duplex inkjet printing device provided by the embodiment of the present invention.

[0158] The control system of the duplex inkjet printing device may include a processor 301 and a memory 302 storing computer program instructions.

[0159] Specifically, the above-mentioned processor 301 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention.

[0160] The memory 302 may include a mass memory for data or instructions. By way of example and 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 suitable cases, the memory 302 may include removable or non-removable (or fixed) media. In suitable cases, the memory 302 may be internal or external to the data processing device. In a particular embodiment, the memory 302 is a non-volatile solid-state memory. In a particular embodiment, the memory 302 includes a read-only memory (ROM). In suitable 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.

[0161] The processor 301 reads and executes the computer program instructions stored in the memory 302 to implement any one of the duplex inkjet printing methods in the above embodiments.

[0162] In one example, the duplex inkjet printing device control system may further include a communication interface 303 and a bus 310. Among them, as Figure 11 shown, the processor 301, the memory 302, and the communication interface 303 are connected through the bus 310 and complete communication with each other.

[0163] The communication interface 303 is mainly used to implement communication between the various modules, devices, units, and / or devices in the embodiments of the present invention.

[0164] The bus 310 includes hardware, software, or both, and couples the components of the duplex inkjet printing device control system to each other. By way of example and not limitation, the bus 310 may include an accelerated graphics port (AGP) or other graphics bus, an enhanced industry standard architecture (EISA) bus, a front-side bus (FSB), a hyperTransport (HT) interconnect, an industry standard architecture (ISA) bus, an InfiniBand interconnect, a low pin count (LPC) bus, a memory bus, a microChannel architecture (MCA) bus, a peripheral component interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a serial advanced technology attachment (SATA) bus, a video electronics standards association local (VLB) bus, or other suitable buses, or a combination of two or more of these. In suitable cases, the bus 310 may include one or more buses. Although the embodiments of the present invention describe and illustrate specific buses, the present invention contemplates any suitable bus or interconnect.

[0165] Embodiment 4

[0166] In addition, in combination with the double-sided inkjet printing method in the above embodiments, an embodiment of the present invention can be implemented by providing a computer-readable storage medium. Computer program instructions are stored on the computer-readable storage medium; when the computer program instructions are executed by the processor 301, any one of the double-sided inkjet printing methods in the above embodiments is implemented.

[0167] It should be clear that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are 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. Those skilled in the art can make various changes, modifications, and additions, or change the order between steps after understanding the spirit of the present invention.

[0168] The functional blocks shown in the above block diagrams 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 used to perform the required tasks. The program or code segment can be stored in a machine-readable medium or transmitted via a data signal carried in a carrier wave on a transmission medium or a communication link. A "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 discs, hard disks, fiber optic media, radio frequency (RF) links, and so on. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0169] 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 executed in the order mentioned in the embodiments, or different from the order in the embodiments, or several steps can be executed simultaneously.

[0170] As described above, only the specific embodiments of the present invention are provided. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A double-sided inkjet printing method based on ink quantity optimization, 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; Among them, 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: obtaining the total ink volume corresponding to the first printing data; determining the preferred values ​​of the ink volume carried by the front and back sides of the printing medium, respectively, recorded as the first preferred ink volume and the second preferred ink volume, respectively; 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.

2. The double-sided inkjet printing method based on ink quantity optimization according to claim 1, 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.

3. The double-sided inkjet printing method based on ink quantity optimization according to claim 1, characterized in that: When the materials of the front and back sides of the printing medium are the same, the first preferred ink amount and the second preferred ink amount are the same; when the materials of the front and back sides of the printing medium are different, the first preferred ink amount and the second preferred ink amount are different.

4. The double-sided inkjet printing method based on ink quantity optimization 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; Wherein i=0,1,2,...N-1, N is a natural number greater than or equal to 1.

5. The double-sided inkjet printing method based on ink quantity optimization according to claim 4, 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.

6. The double-sided inkjet printing method based on ink quantity optimization according to claim 1, characterized in that: The performing data processing on the fourth printing data to obtain fifth printing 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 mirror image printing data is the fifth printing data.

7. The double-sided inkjet printing method based on ink quantity optimization according to claim 6, characterized in that: 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; and / or: Acquire a horizontal alignment deviation between the first test image and the second test image; 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.

8. The double-sided inkjet printing method based on ink quantity optimization 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.

9. A double-sided inkjet printing device based on ink quantity optimization, 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, used for processing the fourth printing data to obtain fifth printing data; A printing module, configured 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 toward 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; A total module acquisition module, used to acquire the total ink volume corresponding to the first printing data, wherein the first printing data is composed of dot data; 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; 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.

10. A double-sided inkjet printing device based on ink quantity optimization, 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 8 is implemented.

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