Real-time calibration ink-jet printer and control system

Abstract

The invention relates to a real-time calibration ink-jet printer and a control system in the field of printers, and the real-time calibration ink-jet printer is characterized in that a camera is used for carrying out feature recognition on a printing material and an actual printing image, and a simulation image is generated based on printing material features and a to-be-printed image; the method comprises the following steps of: firstly selecting a simulation image, then selecting calibration points at the same position in the simulation image and an actual printing image, then calculating offset based on coordinates of the simulation calibration points and printing calibration points, finally calibrating the printer based on the offset, selecting the calibration points for multiple times in the printing process, and calculating the offset. Real-time calibration in the printing process is achieved, a traditional calibration mode that a calibration card is adopted to print images and calibration is conducted depending on naked eye observation is replaced, manual participation is not needed, multiple times of calibration are conducted, and the calibration efficiency and the calibration quality are further improved.

Description

Technical Field

[0001] The invention relates to a calibrated printer, in particular to a real-time calibrated inkjet printer and a control system applied in the field of printers. Background Art

[0002] During the inkjet printing process, the formation of the image depends on the lateral reciprocating movement of the nozzle and the longitudinal advancement of the printed material. However, this process is affected by many factors, including nozzle vibration, the accumulation of lateral movement errors of the nozzle, and the accumulation of longitudinal movement errors of the printed material. As the printing time continues, these errors will gradually accumulate, which will have an adverse effect on the printing quality.

[0003] The existing Chinese patent with publication number CN116373459A discloses a method for calibrating the print deviation of an inkjet printer, including: using an inkjet printer to print a print page for calibration; scanning the print page for calibration and preprocessing it to obtain a print page image; calculating the angle in the horizontal direction of the image and the offset angle in the longitudinal direction; respectively calculating the deviation of all groups of lines in each row of lines, and mapping the offset angle in the longitudinal direction to the deviation corresponding to the longitudinally set lines and mapping the angle in the horizontal direction of the image to the deviation corresponding to the horizontally set lines, to obtain the final deviation of each group of lines; finally, the optimal solution is obtained for the final deviation of each row of lines, that is, the optimal solution is used as the error deviation in each printing mode, and the error deviation in each printing mode is compensated to the printing of the inkjet printer. This method enables the printer to achieve consistency in control of printing in different directions and speeds, and improves the quality of portrait printing.

[0004] The calibration method disclosed in the above patent requires the printer to print an image on a calibration card alone, and then rely on human eyes to judge the image of the calibration card and manually input the calibration parameters. The operation is cumbersome and the calibration accuracy is not high. Summary of the invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that the calibration of the existing spray printer relies on manual judgment and cannot be calibrated in real time.

[0006] To solve the above problems, the present invention provides a real-time calibrated inkjet printer and a control system. The real-time calibrated inkjet printer includes a base and a nozzle. The base is provided with a nozzle displacement mechanism for driving the nozzle to move horizontally. The rear side of the nozzle displacement mechanism is provided with a material displacement mechanism for driving the movement of printing materials. The front side of the nozzle displacement mechanism is provided with a support frame, and a camera is fixedly connected to the support frame. The camera is used to capture the characteristics of the printing material and the printed image; the nozzle displacement mechanism is provided with a first photoelectric encoder for monitoring the movement position of the nozzle, and the material displacement mechanism is provided with a second photoelectric encoder for monitoring the movement position of the material. The nozzle displacement mechanism, the first photoelectric encoder, the material displacement mechanism and the second photoelectric encoder are all connected to the same machine-end controller, and the machine-end controller and the camera are both connected to the same control computer.

[0007] In the above-mentioned real-time calibrated inkjet printer, the features of the printed material and the printed image are acquired and recognized by a camera arranged at the print outlet, so as to facilitate automatic real-time calibration operation.

[0008] A control system for a real-time calibrated inkjet printer, used to control the real-time calibrated inkjet printer as described above, the control system comprising:

[0009] A printing material identification module is connected to the camera output terminal and is used to identify the characteristics of the printing material;

[0010] A simulation image generation module is connected to the output end of the printing material identification module and generates a simulation image based on the printing material characteristics and the image to be printed;

[0011] The simulation calibration point selection module is connected to the output end of the simulation image generation module, and selects two pixel points in different rows on the simulation image as two simulation calibration points;

[0012] A simulated calibration point coordinate acquisition module is connected to the output end of the simulated calibration point selection module, and acquires simulated coordinates of two simulated calibration points based on the characteristics of the simulated image;

[0013] A print image recognition module is connected to the output end of the camera and is used to recognize the features of the print image on the print material;

[0014] A print calibration point recognition module, connected to the output end of the print image recognition module, for recognizing a print calibration point on the print image corresponding to the simulated calibration point;

[0015] A print calibration point coordinate acquisition module is connected to the output end of the print calibration point recognition module, and acquires the print coordinates of two print calibration points based on the features of the print image;

[0016] An offset calculation module is connected to the output ends of the simulation calibration point coordinate acquisition module and the print calibration point coordinate acquisition module respectively, and calculates the offset of the pixel points based on the simulation coordinates of the two simulation calibration points and the print coordinates of the two print calibration points;

[0017] The control module is connected to the output end of the offset calculation module, and its output end is respectively connected to the printing execution module and the calibration module, so as to control the printing operation and the calibration operation. The output ends of the printing execution module and the calibration module are both connected to the machine-side controller, and the output ends of the machine-side controller are respectively connected to the nozzle position mechanism and the material displacement mechanism.

[0018] As a further improvement of the present application, the control system also includes an alarm module connected to the input end of the control module, the input end of the alarm module is connected to a comparison module, the comparison module is connected to the output end of the offset calculation module, the comparison module compares the calculated real-time offset with the set offset threshold, and transmits the comparison result to the alarm module, the alarm module generates an alarm instruction when the real-time offset is greater than the set offset threshold and transmits the alarm instruction to the control module, the control module displays the alarm instruction on the computer and stops the printing operation.

[0019] As a further improvement of the present application, the output end of the calibration module is also connected to a counting module, and the output end of the counting module is connected to the alarm module. The counting module counts the number of calibrations during a single image printing process and compares it with a set calibration number threshold. When the number of calibrations during a single image printing process exceeds the set calibration number threshold, a warning instruction is sent to trigger the alarm module to issue a warning.

[0020] As a further improvement of the present application, the nozzle displacement mechanism includes a movable frame clamped with the nozzle, the movable frame is slidably connected to a fixed frame, and the fixed frame is fixedly connected to the base; a first synchronous belt fixedly connected to the movable frame is provided in the fixed frame, and a first stepper motor is engaged at the end of the first synchronous belt.

[0021] As a further improvement of the present application, the first photoelectric encoder includes a grating bar and a first reader, the grating bar is fixedly connected to the fixed frame and is arranged parallel to the lateral moving path of the movable frame, and the first reader is fixedly connected to the movable frame and is arranged opposite to the grating bar.

[0022] As a further improvement of the present application, the material displacement mechanism includes a paper feed roller and an abutment roller arranged relatively to each other, the paper feed roller is rotatably connected to a fixed plate fixedly connected to the base, a second stepper motor is fixedly connected above the fixed plate, and the output shaft of the second stepper motor is connected to the paper feed roller for transmission through a second synchronous belt.

[0023] As a further improvement of the present application, the second photoelectric encoder includes a grating disk and a second reader. The grating disk is fixedly sleeved on the output shaft of the second stepper motor. The second reader is sleeved on the outside of the grating disk and fixedly connected to the fixed plate. The position of the printed material is monitored by the second photoelectric encoder.

[0024] As a further improvement of the present application, when the above control system is used to perform real-time calibration on the inkjet printer, the following steps are included:

[0025] Step 1, generating a simulated image, loading the material to be printed into the printer, inputting the image to be printed into the computer, starting the camera to shoot the printed material, and generating a simulated image based on the printed material;

[0026] Step 2: According to the order of image printing, two pixel points in different rows on the simulated image corresponding to the image to be printed are selected as two simulated calibration points, and the coordinates of the two simulated calibration points are obtained based on the positions of the two pixel points on the simulated image; the method for obtaining the coordinates of the two simulated calibration points includes the following sub-steps:

[0027] S1, confirm the simulated coordinates of the first simulated calibration point, take the lateral distance M1 between the first simulated calibration point in the simulated image and the edge of the printed material as the simulated abscissa of the first simulated calibration point, and define the simulated ordinate of the first simulated calibration point as 0, then the simulated coordinates of the first simulated calibration point are (M1, O);

[0028] S2, then obtain the lateral distance m2 and the longitudinal distance H2 between the second simulated calibration point and the first simulated calibration point based on the simulated image, and obtain the simulated coordinates of the second simulated calibration point as (M2, H2), where M2=M1+m2;

[0029] Step 3: Print the image and obtain the real-time printing image through the camera. During the printing process, when two printing calibration points corresponding to the two simulated calibration points appear in the printed image, close the printing mechanism and analyze the printed image to obtain the printing coordinates of the two printing calibration points on the printed image. The specific steps are as follows:

[0030] A1, confirm the printing coordinates of the first printing calibration point, take the horizontal distance D1 between the first printing calibration point and the edge of the printing material in the printing image as the printing horizontal coordinate of the first printing calibration point, and define the printing vertical coordinate of the first printing calibration point as 0, then the simulation coordinates of the first printing calibration point are (D1, O);

[0031] A2, then based on the printed image, obtain the lateral distance d2 and the longitudinal distance L2 between the second print calibration point and the first print calibration point, and obtain the print coordinates of the second print calibration point as (D2, L2), where D2 = D1 + d2;

[0032] Step 4, based on the coordinates of the simulated calibration point and the printed calibration point, calculate the lateral offset and the longitudinal offset. First, calculate the lateral offset P lateral, P lateral = M1 - D1, and then calculate the longitudinal offset P longitudinal, P longitudinal = H2 - L2;

[0033] Step 5: According to the lateral offset and longitudinal offset calculated in step 4, the real-time position of the nozzle is adjusted by the nozzle displacement mechanism, and the real-time position of the printing material is adjusted by the material displacement hook. After the calibration is completed, continue printing;

[0034] Step six, repeat steps two to five, perform multiple offset calculations and calibrations, and implement real-time calibration during the printing process.

[0035] In summary, the present invention uses a camera to perform feature recognition on the printing material and the actual printed image, and generates a simulated image based on the features of the printing material and the image to be printed, then selects calibration points at the same position in the simulated image and the actual printed image, and then calculates the offset based on the coordinates of the simulated calibration points and the printed calibration points, and finally calibrates the printer based on the offset. During the printing process, calibration points are selected and the offset is calculated multiple times to achieve real-time calibration during the printing process, replacing the traditional calibration method of using a calibration card to print an image and relying on naked eye observation for calibration. No human intervention is required, and multiple calibrations are performed to further improve the calibration efficiency and calibration quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the three-dimensional structure of this application;

[0037] Figure 2 It is a schematic diagram of the explosion structure of the nozzle displacement mechanism in this application;

[0038] Figure 3 It is a schematic diagram of the explosion structure of the material displacement mechanism in this application;

[0039] Figure 4 This is a schematic diagram of the longitudinal cross-sectional structure of the present application;

[0040] Figure 5 This is a module diagram of the control system in this application;

[0041] Figure 6 A schematic diagram of printing calibration points and simulation calibration points in this application;

[0042] Figure 7 This is the flow chart of the calibration process for this application.

[0043] Description of the numbers in the figure:

[0044] 1. Base; 2. Nozzle; 3. Nozzle displacement mechanism; 4. First photoelectric encoder; 401. Grating strip; 402. First reader; 5. Material displacement mechanism; 6. Second photoelectric encoder; 601. Grating disk; 602. Second reader; 7. Support frame; 8. Camera; 9. Moving frame; 10. Fixed frame; 11. First synchronous belt; 12. First stepper motor; 13. Second synchronous belt; 14. Second stepper motor; 15. Fixed plate; 16. Paper feed roller; 17. Abutment roller; 18. Machine-end controller. DETAILED DESCRIPTION

[0045] The following describes two implementation modes of the present application in detail with reference to the accompanying drawings.

[0046] The first implementation method:

[0047] Figure 1-7 A real-time calibrated inkjet printer is shown, comprising a base 1 and a nozzle 2. The base 1 is provided with a nozzle displacement mechanism 3 for driving the nozzle 2 to move horizontally. The rear side of the nozzle displacement mechanism 3 is provided with a material displacement mechanism 5 for driving the printing material to move. The front side of the nozzle displacement mechanism 3 is provided with a support frame 7. A camera 8 is fixedly connected to the support frame 7. The camera 8 is used to capture the characteristics of the printing material and the printed image. The nozzle displacement mechanism 3 is provided with a first photoelectric encoder 4 for monitoring the moving position of the nozzle 2. The material displacement mechanism 5 is provided with a second photoelectric encoder 6 for monitoring the moving position of the material. The nozzle displacement mechanism 3, the first photoelectric encoder 4, the material displacement mechanism 5 and the second photoelectric encoder 6 are all connected to the same machine-end controller 18. The machine-end controller 18 and the camera 8 are both connected to the same control computer.

[0048] Specifically, the nozzle displacement mechanism 3 drives the nozzle 2 to move horizontally, and the nozzle 2 performs inkjet printing on the printing material, while the material displacement mechanism 5 pushes the printing material to move in a stable gap under the nozzle 2, so that the nozzle 2 prints rows of inkjet dots on the printing material.

[0049] See also Figure 2 and Figure 4 The nozzle displacement mechanism 3 includes a moving frame 9 clamped with the nozzle 2, the moving frame 9 is slidably connected with a fixed frame 10, and the fixed frame 10 is fixedly connected with the base 1; a first synchronous belt 11 fixedly connected with the moving frame 9 is provided in the fixed frame 10, and a first stepper motor 12 is engaged with the end of the first synchronous belt 11; the first stepper motor 12 drives the first synchronous belt 11 to reciprocate, and the first synchronous belt 11 drives the moving frame 9 to reciprocate laterally on the fixed frame 10, and the moving frame 9 drives the nozzle 2 to move laterally above the printing material to control the position of the nozzle 2.

[0050] See also Figure 2 and Figure 4The first photoelectric encoder 4 includes a grating bar 401 and a first reader 402. The grating bar 401 is fixedly connected to the fixed frame 10 and is arranged parallel to the lateral moving path of the movable frame 9. The first reader 402 is fixedly connected to the movable frame 9 and is arranged opposite to the grating bar 401. The first reader 402 includes a light source and a photoelectric sensor. The first reader 402 emits the light source onto the grating bar 401 and receives the reflected light, thereby calculating the position of the movable frame 9 and the nozzle 2 thereon.

[0051] See also Figure 3 and Figure 4 The material displacement mechanism 5 includes a paper feed roller 16 and an abutting roller 17 that are relatively arranged. The paper feed roller 16 is rotatably connected to a fixed plate 15 that is fixedly connected to the base 1. A second stepper motor 14 is fixedly connected above the fixed plate 15. The output shaft of the second stepper motor 14 is connected to the paper feed roller 16 through a second synchronous belt 13. The second stepper motor 14 drives the paper feed roller 16 to rotate through the second synchronous belt 13, and the paper feed roller 16 pushes the printing material to move stably under the nozzle 2.

[0052] See also Figure 3 and Figure 4 The second photoelectric encoder 6 includes a grating disk 601 and a second reader 602. The grating disk 601 is fixedly sleeved on the output shaft of the second stepping motor 14. The second reader 602 is sleeved on the outside of the grating disk 601 and fixedly connected to the fixed plate 15. The position of the printed material is monitored by the second photoelectric encoder 6.

[0053] See also Figure 1 and Figure 5 The computer is equipped with a control system, which includes:

[0054] A printed material identification module is connected to the output end of the camera 8 and is used to identify the characteristics of the printed material;

[0055] A simulation image generation module is connected to the output end of the printing material identification module and generates a simulation image based on the printing material characteristics and the image to be printed;

[0056] The simulation calibration point selection module is connected to the output end of the simulation image generation module, and selects two pixel points in different rows on the simulation image as two simulation calibration points;

[0057] A simulated calibration point coordinate acquisition module is connected to the output end of the simulated calibration point selection module, and acquires simulated coordinates of two simulated calibration points based on the characteristics of the simulated image;

[0058] A print image recognition module, connected to the output end of the camera 8, for recognizing features of the print image on the print material;

[0059] A print calibration point recognition module, connected to the output end of the print image recognition module, for recognizing a print calibration point on the print image corresponding to the simulated calibration point;

[0060] A print calibration point coordinate acquisition module is connected to the output end of the print calibration point recognition module, and acquires the print coordinates of two print calibration points based on the features of the print image;

[0061] An offset calculation module is connected to the output ends of the simulation calibration point coordinate acquisition module and the print calibration point coordinate acquisition module respectively, and calculates the offset of the pixel points based on the simulation coordinates of the two simulation calibration points and the print coordinates of the two print calibration points;

[0062] The control module is connected to the output end of the offset calculation module, and its output ends are respectively connected to the printing execution module and the calibration module, so as to control the printing operation and the calibration operation. The output ends of both the printing execution module and the calibration module are connected to the machine-end controller 18, and the output ends of the machine-end controller 18 are respectively connected to the nozzle position mechanism 3 and the material displacement mechanism 5.

[0063] For details, please refer to Figure 5-7 When the above control system is used to calibrate the inkjet printer in real time, the following steps are included:

[0064] Step 1, generating a simulated image, loading the material to be printed into the printer, inputting the image to be printed into the computer, starting the camera 8 to shoot the printed material, and generating a simulated image based on the printed material;

[0065] Specifically, the printing material recognition module recognizes the image on the printing material captured by the camera 8 to obtain the characteristics of the printing material, the printing material characteristics including the width and edge position of the printing material, and the simulation image production module generates a simulation image based on the characteristics of the printing material, the simulation image including the simulation position of each pixel point on the printing material and the lateral distance between each pixel point and the edge position of the printing material;

[0066] It should be noted that this simulated image is equivalent to the image produced when the printer accurately prints on the printing material;

[0067] Step 2, see Figure 5 , according to the order of image printing, two pixel points in different rows on the simulated image corresponding to the image to be printed are selected as two simulated calibration points, and the coordinates of the two simulated calibration points are obtained based on the positions of the two pixel points on the simulated image; the method for obtaining the coordinates of the two simulated calibration points includes the following sub-steps:

[0068] S1, confirm the simulated coordinates of the first simulated calibration point, take the lateral distance M1 between the first simulated calibration point in the simulated image and the edge of the printed material as the simulated abscissa of the first simulated calibration point, and define the simulated ordinate of the first simulated calibration point as 0, then the simulated coordinates of the first simulated calibration point are (M1, O);

[0069] S2, then obtain the lateral distance m2 and the longitudinal distance H2 between the second simulated calibration point and the first simulated calibration point based on the simulated image, and obtain the simulated coordinates of the second simulated calibration point as (M2, H2), where M2=M1+m2;

[0070] Specifically, when selecting the first simulated calibration point on the simulated image, in order to determine its coordinates, its horizontal coordinate is defined as the horizontal distance of the pixel point from the edge of the printed material, and its vertical coordinate is defined as zero, thereby facilitating the determination of the simulated coordinates of the second simulated calibration point;

[0071] It should be noted that when simulating the selection of calibration points, calibration points that are easy to locate are selected based on the features of the image, such as the pixel points at the corners of the graphics in the image, the geometric center of the graphics in the image, the center of the line, or two pixel points with large color differences. In addition, since the nozzle 2 prints line by line when printing the image, in order to ensure the longitudinal offset, the two calibration points cannot be selected in the same line;

[0072] Step 3: Print the image. Figure 5 , and obtain a real-time printing image through the camera 8. During the printing process, when two printing calibration points corresponding to the two simulated calibration points appear in the printed image, the printing mechanism is closed, and the printed image is analyzed to obtain the printing coordinates of the two printing calibration points on the printed image. The specific steps are as follows:

[0073] A1, confirm the printing coordinates of the first printing calibration point, take the horizontal distance D1 between the first printing calibration point and the edge of the printing material in the printing image as the printing horizontal coordinate of the first printing calibration point, and define the printing vertical coordinate of the first printing calibration point as 0, then the simulation coordinates of the first printing calibration point are (D1, O);

[0074] A2, then based on the printed image, obtain the lateral distance d2 and the longitudinal distance L2 between the second print calibration point and the first print calibration point, and obtain the print coordinates of the second print calibration point as (D2, L2), where D2 = D1 + d2;

[0075] Specifically, the two printing calibration points refer to the pixel points at the corresponding positions on the actual printed image and the simulated image. For example, if the printed image contains a triangular figure, the calibration points are selected as the pixel points at the two corners that are not in the same row, so as to facilitate the positioning and identification of the printing calibration points and the calculation of the offset.

[0076] Step 4, calculate the lateral offset and the longitudinal offset, first calculate the lateral offset Plateral, Plateral=M1-D1, then calculate the longitudinal offset Plongitudinal, Plongitudinal=H2-L2;

[0077] It should be noted that when P is defined as zero in the horizontal direction, no lateral offset occurs. When P is greater than zero in the horizontal direction, the printed calibration point is offset to the left compared to the simulated calibration point. When P is less than zero in the horizontal direction, the printed calibration point is offset to the right compared to the simulated calibration point. Similarly, when P is equal to zero in the longitudinal direction, no longitudinal offset occurs. When P is greater than zero in the longitudinal direction, the printed calibration point is offset downward in the longitudinal direction compared to the molded calibration point. When P is less than zero in the longitudinal direction, the printed calibration point is offset upward in the longitudinal direction compared to the simulated calibration point.

[0078] Step 5: According to the lateral offset and longitudinal offset calculated in step 4, the real-time position of the nozzle is adjusted by the nozzle displacement mechanism, and the real-time position of the printing material is adjusted by the material displacement hook. After the calibration is completed, continue printing;

[0079] Step six, repeat steps two to five, perform multiple offset calculations and calibrations, and implement real-time calibration during the printing process.

[0080] Compared with the traditional inkjet printer method, the present invention uses the camera 8 to perform feature recognition on the printing material and the actual printed image, and generates a simulated image based on the characteristics of the printing material and the image to be printed, and then selects calibration points at the same position in the simulated image and the actual printed image, and calculates the offset based on the coordinates of the simulated calibration points and the printed calibration points. During the printing process, calibration points are selected and the offset is calculated multiple times to achieve real-time calibration during the printing process, replacing the traditional calibration method of using a calibration card to print an image and relying on naked eye observation for calibration. No human intervention is required, and multiple calibrations are performed to further improve the calibration efficiency and calibration quality.

[0081] Second implementation method:

[0082] Figure 5A real-time calibrated inkjet printer and control system are shown. Based on the first embodiment, the control system also includes an alarm module connected to the input end of the control module. The input end of the alarm module is connected to a comparison module. The comparison module is connected to the output end of the offset calculation module. The comparison module compares the calculated real-time offset with the set offset threshold and transmits the comparison result to the alarm module. When the real-time offset is greater than the set offset threshold, the alarm module generates an alarm instruction and transmits the alarm instruction to the control module. The control module displays the alarm instruction on a computer and stops the printing operation.

[0083] Specifically, by setting an offset threshold, when the real-time offset is greater than the set offset threshold, an alarm is issued and the printing operation is stopped, reminding the operator to check whether the hardware of the printer is damaged.

[0084] See also Figure 5 The output end of the calibration module is also connected to a counting module, and the output end of the counting module is connected to the alarm module. The counting module counts the number of calibrations during a single image printing process and compares it with a set calibration threshold. When the number of calibrations during a single image printing process exceeds the set calibration threshold, an early warning instruction is sent to trigger the alarm module to issue an early warning.

[0085] Specifically, when a single image is calibrated too many times during the printing process, it not only increases power consumption, but is more likely to indicate hardware damage, requiring timely maintenance to reduce energy consumption.

[0086] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. A real-time calibrated inkjet printer, characterized in that: The invention comprises a base (1) and a nozzle (2), wherein the base (1) is provided with a nozzle displacement mechanism (3) for driving the nozzle (2) to move horizontally, the rear side of the nozzle displacement mechanism (3) is provided with a material displacement mechanism (5) for driving the printing material to move, the front side of the nozzle displacement mechanism (3) is provided with a support frame (7), the support frame (7) is fixedly connected with a camera (8), the camera (8) is used to capture the characteristics of the printing material and the printed image; the nozzle displacement mechanism (3) is provided with a first photoelectric encoder (4) for monitoring the moving position of the nozzle (2), the material displacement mechanism (5) is provided with a second photoelectric encoder (6) for monitoring the moving position of the material, the nozzle displacement mechanism (3), the first photoelectric encoder (4), the material displacement mechanism (5) and the second photoelectric encoder (6) are all connected to the same machine-end controller (18), and the machine-end controller (18) and the camera (8) are both connected to the same control computer.

2. A control system for a real-time calibrated inkjet printer, used to control the real-time calibrated inkjet printer as claimed in claim 1, characterized in that: The control system includes: A printed material identification module, connected to the output end of the camera (8), for identifying the characteristics of the printed material; A simulation image generation module is connected to the output end of the printing material identification module and generates a simulation image based on the printing material characteristics and the image to be printed; The simulation calibration point selection module is connected to the output end of the simulation image generation module, and selects two pixel points in different rows on the simulation image as two simulation calibration points; A simulated calibration point coordinate acquisition module is connected to the output end of the simulated calibration point selection module, and acquires simulated coordinates of two simulated calibration points based on the characteristics of the simulated image; A print image recognition module connected to the output end of the camera (8) and used to recognize features of a print image on a print material; A print calibration point recognition module, connected to the output end of the print image recognition module, for recognizing a print calibration point on the print image corresponding to the simulated calibration point; A print calibration point coordinate acquisition module is connected to the output end of the print calibration point recognition module, and acquires the print coordinates of two print calibration points based on the features of the print image; An offset calculation module is connected to the output ends of the simulation calibration point coordinate acquisition module and the print calibration point coordinate acquisition module respectively, and calculates the offset of the pixel points based on the simulation coordinates of the two simulation calibration points and the print coordinates of the two print calibration points; The control module is connected to the output end of the offset calculation module, and its output end is respectively connected to the printing execution module and the calibration module, so as to control the printing operation and the calibration operation. The output ends of the printing execution module and the calibration module are both connected to the machine-side controller (18), and the output end of the machine-side controller (18) is respectively connected to the nozzle position mechanism (3) and the material displacement mechanism (5).

3. A control system for a real-time calibrated inkjet printer according to claim 2, characterized in that: The control system also includes an alarm module connected to the input end of the control module, the input end of the alarm module is connected to a comparison module, the comparison module is connected to the output end of the offset calculation module, the comparison module compares the calculated real-time offset with the set offset threshold, and transmits the comparison result to the alarm module, the alarm module generates an alarm instruction when the real-time offset is greater than the set offset threshold and transmits the alarm instruction to the control module, the control module displays the alarm instruction on the computer and stops the printing operation.

4. A control system for a real-time calibrated inkjet printer according to claim 3, characterized in that: The output end of the calibration module is also connected to a counting module, and the output end of the counting module is connected to the alarm module. The counting module counts the number of calibrations during a single image printing process and compares it with a set calibration number threshold. When the number of calibrations during a single image printing process exceeds the set calibration number threshold, an early warning instruction is sent to trigger the alarm module to issue an early warning.

5. The real-time calibrated inkjet printer according to claim 1, characterized in that: The nozzle displacement mechanism (3) comprises a movable frame (9) clamped with the nozzle (2), the movable frame (9) being slidably connected to a fixed frame (10), and the fixed frame (10) being fixedly connected to the base (1); a first synchronous belt (11) fixedly connected to the movable frame (9) is arranged in the fixed frame (10), and a first stepper motor (12) is meshed at the end of the first synchronous belt (11).

6. The real-time calibrated inkjet printer according to claim 5, characterized in that: The first photoelectric encoder (4) comprises a grating bar (401) and a first reader (402); the grating bar (401) is fixedly connected to a fixed frame (10) and is arranged parallel to a transverse moving path of a movable frame (9); and the first reader (402) is fixedly connected to the movable frame (9) and is arranged opposite to the grating bar (401).

7. The real-time calibrated inkjet printer according to claim 1, characterized in that: The material displacement mechanism (5) comprises a paper feed roller (16) and an abutment roller (17) arranged opposite to each other; the paper feed roller (16) is rotatably connected to a fixed plate (15) fixedly connected to the base (1); a second stepper motor (14) is fixedly connected above the fixed plate (15); and an output shaft of the second stepper motor (14) is connected to the paper feed roller (16) for transmission via a second synchronous belt (13).

8. The real-time calibrated inkjet printer according to claim 7, characterized in that: The second photoelectric encoder (6) comprises a grating disk (601) and a second reader (602). The grating disk (601) is fixedly sleeved on the output shaft of the second stepping motor (14). The second reader (602) is sleeved on the outside of the grating disk (601) and fixedly connected to the fixed plate (15). The position of the printed material is monitored by the second photoelectric encoder (6).

9. The control system of a real-time calibrated inkjet printer according to claim 2, characterized in that: When the control system is used to calibrate the inkjet printer in real time, the following steps are included: Step 1, generating a simulated image, loading the material to be printed into the printer, inputting the image to be printed into the computer, starting the camera (8) to shoot the printed material, and generating a simulated image based on the printed material; Step 2: According to the order of image printing, two pixel points in different rows on the simulated image corresponding to the image to be printed are selected as two simulated calibration points, and the coordinates of the two simulated calibration points are obtained based on the positions of the two pixel points on the simulated image; the method for obtaining the coordinates of the two simulated calibration points includes the following sub-steps: S1, confirm the simulated coordinates of the first simulated calibration point, take the lateral distance M1 between the first simulated calibration point in the simulated image and the edge of the printed material as the simulated abscissa of the first simulated calibration point, and define the simulated ordinate of the first simulated calibration point as 0, then the simulated coordinates of the first simulated calibration point are (M1, O); S2, then obtain the lateral distance m2 and the longitudinal distance H2 between the second simulated calibration point and the first simulated calibration point based on the simulated image, and obtain the simulated coordinates of the second simulated calibration point as (M2, H2), where M2=M1+m2; Step 3, printing the image and obtaining the real-time printed image through the camera (8). During the printing process, when two printing calibration points corresponding to the two simulated calibration points appear in the printed image, the printing mechanism is closed, and the printed image is analyzed to obtain the printing coordinates of the two printing calibration points on the printed image. The specific steps are as follows: A1, confirm the printing coordinates of the first printing calibration point, take the horizontal distance D1 between the first printing calibration point and the edge of the printing material in the printing image as the printing horizontal coordinate of the first printing calibration point, and define the printing vertical coordinate of the first printing calibration point as 0, then the simulation coordinates of the first printing calibration point are (D1, O); A2, then based on the printed image, obtain the lateral distance d2 and the longitudinal distance L2 between the second print calibration point and the first print calibration point, and obtain the print coordinates of the second print calibration point as (D2, L2), where D2 = D1 + d2; Step 4, based on the coordinates of the simulated calibration point and the printed calibration point, the lateral offset and the longitudinal offset are calculated. First, the lateral offset P lateral is calculated, where P lateral = M1 - D1, and then the longitudinal offset P longitudinal is calculated, where P longitudinal = H2 - L2; Step 5: According to the lateral offset and longitudinal offset calculated in step 4, the real-time position of the nozzle is adjusted by the nozzle displacement mechanism, and the real-time position of the printing material is adjusted by the material displacement hook. After the calibration is completed, continue printing; Step 6: Repeat steps 2 to 5 to perform multiple offset calculations and calibrations to achieve real-time calibration during the printing process.

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