A correction system

Abstract

This specification provides a correction system. The correction system may include a paper feeding mechanism, a scanning module, an inkjet module, and a control module. When the paper moves through the paper feeding mechanism, it first passes through the scanning module, which has opposing first and second scanning mechanisms, thus capturing surface images of both sides of the paper as it passes through the gap between them. Then, the paper passes through the inkjet module. The control module can scan the surface image of the paper to be corrected during its movement along a preset transport path, determine the correction content, and control the inkjet mechanism to print based on the paper's transport speed and position. The implementation method provided in this specification can significantly improve the efficiency of paper correction. Furthermore, neither the scanning module nor the inkjet module needs to include displacement elements; scanning and correction of the entire sheet of paper can be achieved simply by the movement of the paper. Therefore, the device occupies minimal space and is easy to maintain.

Description

Technical Field

[0001] This manual relates to the field of homework correction technology, and in particular to a correction system. Background Technology

[0002] Faced with a large number of assignments to be processed daily in educational institutions such as schools, the traditional method of manual grading often consumes a huge amount of manpower and time. Therefore, automatic grading of assignments based on computer equipment has become a promising technological development direction.

[0003] In related technologies, it is usually necessary to scan the homework into the computer using a scanner, and then send the grading results to the student's parents' mobile phones electronically after grading, or print out the grading results using a printer. However, the convenience is still not high enough. Summary of the Invention

[0004] In view of this, this specification provides a grading system, the grading system comprising: A paper feeding mechanism is used to acquire the paper to be corrected and drive the paper to be corrected to move along a preset transport path. The scanning module includes a first scanning mechanism and a second scanning mechanism arranged opposite to each other. The preset transport path passes through a first gap between the first scanning mechanism and the second scanning mechanism. The first scanning mechanism and the second scanning mechanism are respectively used to acquire surface images of the two surfaces of the paper to be corrected passing through the first gap. An inkjet module is disposed downstream of the scanning module along the preset transport path, and includes a first inkjet mechanism and a second inkjet mechanism disposed opposite to each other. The preset transport path passes through a second gap between the first inkjet mechanism and the second inkjet mechanism. The first inkjet mechanism and the second inkjet mechanism are respectively used to print content on two surfaces of the paper to be corrected passing through the second gap. The control module is used to determine the correction content corresponding to the two surfaces of the paper to be corrected based on the surface images acquired by the first scanning mechanism and the second scanning mechanism, and to control the first inkjet mechanism and the second inkjet mechanism to print the corresponding correction content on the two surfaces of the paper to be corrected according to the transmission speed and position of the paper to be corrected.

[0005] Optionally, both the first inkjet mechanism and the second inkjet mechanism include: Mounting plate; Multiple printhead modules are staggered along a first direction and assembled on the mounting plate. Each printhead module includes multiple nozzles arranged along the first direction. The nozzles are used to print pixels. The first direction is perpendicular to the second direction and the third direction. The second direction is the paper surface direction when the paper to be corrected passes through the second gap along the preset transport path. The third direction is the movement direction of the paper to be corrected when it passes through the second gap along the preset transport path.

[0006] Optionally, the correction content consists of at least one pixel to be printed in the coordinate system of the paper to be corrected, and the inkjet module is used to print pixels at each pixel to be printed in the correction content.

[0007] Optionally, the control module is configured to: For each pixel to be printed on the two surfaces of the paper to be corrected, the nozzle number and delay time corresponding to the pixel to be printed are determined according to the transmission speed and position of the paper to be corrected. The nozzle number is used to identify the nozzle in the inkjet module. After waiting for the delay time, the nozzle corresponding to the nozzle number is controlled to print pixels.

[0008] Optionally, the control module is configured to: The surface images acquired by the first scanning mechanism and the surface images acquired by the second scanning mechanism are sent to the server, so that the server determines the correction content corresponding to the two surfaces of the paper to be corrected based on the received surface images, and sequentially sends the pixel row to the control module for each pixel row of the correction content, wherein the pixel row includes at least one pixel to be printed arranged in the first direction; After receiving the next pixel row of the currently printed pixel row, the paper feeding mechanism is controlled to continue carrying the paper to be corrected a preset distance, and the inkjet module is controlled to print the next pixel row, wherein the preset distance is the height of the pixel to be printed; If the next pixel line of the currently printed pixel line is not received, the paper feeding mechanism is controlled to pause the transport of the paper to be corrected.

[0009] Optionally, the control module is configured to: The surface images acquired by the first scanning mechanism and the surface images acquired by the second scanning mechanism are sent to the server, so that the server determines at least one correction mark corresponding to the two surfaces of the paper to be corrected and the target position of each correction mark based on the received surface images, and sends the at least one correction mark and the target position of each correction mark to the control module. According to a preset symbol library, the geometric drawing rule corresponding to each received correction mark is determined, and at the target position of each received correction mark, the corresponding pixel to be printed is determined based on the corresponding geometric drawing rule, so as to determine the correction content corresponding to the two surfaces of the paper to be corrected. The symbol library is used to record the mapping relationship between correction marks and geometric drawing rules.

[0010] Optionally, the projection of each printhead module of the first inkjet mechanism onto the mounting plate of the second inkjet mechanism along the second direction does not coincide with each printhead module of the second inkjet mechanism.

[0011] Optionally, each printhead module also includes multiple inkjet valves, each inkjet valve corresponding to one of the multiple nozzles included in the printhead module, and the inkjet valve is connected to the end of the corresponding nozzle away from the preset transport path. The inkjet module also includes: Ink tank, used to hold ink; The ink guide channel is connected at one end to the ink tank and at the other end to the end of each inkjet valve in the first inkjet mechanism that is away from the corresponding nozzle, and to the end of each inkjet valve in the second inkjet mechanism that is away from the corresponding nozzle. The control module is configured as follows: By controlling the opening and closing of each inkjet valve in the first inkjet mechanism and the opening and closing of each inkjet valve in the second inkjet mechanism, the first inkjet mechanism and the second inkjet mechanism are controlled to print the corresponding correction content on the two surfaces of the paper to be corrected.

[0012] Optionally, the grading system further includes: The paper feed buffer is located at the starting end of the preset transport path and is used to hold the paper to be corrected; The paper feed roller abuts against the surface of the paper contained in the paper feed buffer, and is used to transport the paper contained in the paper feed buffer to the paper feeding mechanism by friction. The paper output buffer compartment is located at the end of the preset transport path and is used to hold the paper to be corrected.

[0013] Optionally, in the preset transport path, the length of the portion located between the first gap and the second gap is greater than the length of the paper to be corrected; The control module is configured as follows: After the paper to be corrected carried by the paper feeding mechanism passes through the first gap, the paper feeding mechanism is controlled to stop carrying the paper to be corrected. After determining the correction content corresponding to the two surfaces of the paper to be corrected, the paper feeding mechanism is controlled to continue carrying the paper to be corrected.

[0014] In the embodiments of this specification, the correction system includes a paper feeding mechanism, a scanning module, an inkjet module, and a control module. When the paper moves through the paper feeding mechanism, it first passes through the scanning module, which has a first scanning mechanism and a second scanning mechanism, thus capturing surface images of both sides of the paper passing through the gap between them. Then, the paper passes through the inkjet module. The control module can scan the surface image of the paper to be corrected and determine the correction content based on the paper's movement along a preset transport path, and control the inkjet mechanism to print according to the paper's transport speed and position. The embodiment provided in this specification places the double-sided inkjet module downstream of the double-sided scanning module. Therefore, the paper only needs to move along a planar path from one end to the other to complete scanning and correction, eliminating the need for flipping or single-sided rescanning, significantly improving the efficiency of paper correction. Simultaneously, neither the scanning module nor the inkjet module needs to include displacement elements; scanning and correction of the entire sheet of paper can be achieved simply by the movement of the paper. Therefore, the device occupies minimal space and is easy to maintain. Attached Figure Description

[0015] Figure 1 These are schematic diagrams illustrating the structure of a correction system through some exemplary embodiments.

[0016] Figure 2 This is a hardware structure diagram of a control module illustrating some exemplary embodiments.

[0017] Figure 3 This is a block diagram illustrating a control module as shown in some exemplary embodiments.

[0018] Figure 4 These are schematic diagrams illustrating an inkjet mechanism through some exemplary embodiments.

[0019] Figure 5 These are perspective views illustrating an inkjet mechanism, as shown in some exemplary embodiments.

[0020] Figure 6 These are schematic diagrams illustrating the structure of another grading system, as shown in some exemplary embodiments. Detailed Implementation

[0021] As described in the background section, related technologies typically require scanning assignments into a computer using a separate scanner. After grading, the grading results are then sent electronically to the student's or parent's mobile phone, or printed out using a printer. However, this method is not very convenient.

[0022] In view of this, this specification provides a correction system.

[0023] This manual provides a grading system. Please refer to [link / reference]. Figure 1 This is a cross-sectional view of a correction system shown in this specification. The correction system may include a paper feeding mechanism 110, a scanning module 120, an inkjet module 130, and a control module.

[0024] The paper feeding mechanism 110 is used to acquire the paper to be corrected and drive it to move along a preset transport path 140; Figure 1 In the paper feeding mechanism 110, there are paper feed rollers 111 for moving the paper by friction and guide plates 112 for controlling the paper's direction. The scanning module 120 may include a first scanning mechanism 121 and a second scanning mechanism 122 arranged opposite to each other. A preset transport path 140 passes through a first gap between the first scanning mechanism 121 and the second scanning mechanism 122. The first scanning mechanism 121 and the second scanning mechanism 122 are respectively used to acquire surface images of the two surfaces of the paper to be corrected passing through the gap.

[0025] The inkjet module 130 is disposed downstream of the scanning module 120 along a preset transport path 140, and may include a first inkjet mechanism 131 and a second inkjet mechanism 132 disposed opposite to each other. The preset transport path 140 passes through a second gap between the first inkjet mechanism 131 and the second inkjet mechanism 132. The first inkjet mechanism 131 and the second inkjet mechanism 132 are respectively used to print content on the two surfaces of the paper to be corrected passing through the gap.

[0026] The control module is used to determine the correction content corresponding to the two surfaces of the paper to be corrected based on the surface image collected by the first scanning mechanism 121 and the surface image collected by the second scanning mechanism 122, and to control the first inkjet mechanism 131 and the second inkjet mechanism 132 to print the corresponding correction content on the two surfaces of the paper to be corrected according to the transmission speed and position of the paper to be corrected.

[0027] The grading system, also known as a grading machine, is a device used to receive paper and leave marks on it based on the content. It can be applied to scenarios such as homework grading, exam paper scoring, and document signing. The preset transport path 140 can be a trajectory for paper movement consisting of guide rails (including baffles), conveyor belts, or multiple sets of rollers.

[0028] The first scanning mechanism 121 and the second scanning mechanism 122 can be implemented based on a CIS (Contact Image Sensor) module, thereby further reducing the size occupied by the device; or, they can be implemented based on a camera, which is not limited in this specification.

[0029] As the paper moves unidirectionally along a single path driven by the paper feeding mechanism 110, it first passes through the first gap of the scanning module 120. At this time, the two scanning mechanisms arranged above and below the paper can simultaneously acquire images of both sides of the paper, allowing the control module to obtain surface images of both surfaces of the paper. Then, it generates correction content based on these surface images. Subsequently, the paper continues to move forward and enters the second gap of the inkjet module 130. The two inkjet mechanisms arranged above and below the paper can then directly print marks on both sides of the paper according to the correction content determined by the control module.

[0030] Please refer to Figure 2 At the hardware level, the control module may include a processor 202, an internal bus 204, a network interface 206, memory 208, and non-volatile memory 210, and may also include other hardware required for its functions. The steps executed by the control module can be implemented in software, such as the processor 202 reading the corresponding computer program from the non-volatile memory 210 into memory 208 and then running it.

[0031] In some embodiments of this specification, the process by which the control module determines the correction content of the paper to be corrected based on the surface image can be directly executed by the control module local to the correction system, or the control module can send the surface image to a cloud server or local computer that is communicatively connected to the correction system, whereby the cloud server or local computer processes the image to obtain the correction content and then returns it to the control module. For example, please refer to [link to relevant documentation]. Figure 3 The device used to obtain the correction content based on the surface image (i.e., control module, cloud server or local computer, the following description will take the control module itself as an example) can be configured with an image segmentation module 310, a test question positioning module 320, an OCR (Optical Character Recognition) module 330 and a large language model 340.

[0032] After acquiring the surface images of the two surfaces of the paper collected by the first scanning mechanism 121 and the second scanning mechanism 122 respectively, the control module can perform pose correction on the two surface images. During actual transport, the paper may experience slight tilting or translational shifts when passing through the first gap. Therefore, the control module can determine the actual deflection angle and translation amount of the paper to be corrected by identifying the paper edge contours in the surface images, preset alignment marks (such as the positioning black blocks at the four corners of the exam paper), or the text layout direction in the surface images. Based on this, the control module performs rotation and affine transformations on the two surface images respectively, aligning the images of the two surfaces with the actual physical coordinate system of the paper to be corrected on the preset transport path 140 in the spatial coordinate system, thereby ensuring the accuracy of the subsequent printing position.

[0033] After the image correction is completed, the control module may invoke the test question positioning module 320 and the image segmentation module 310 to process the images of the front and back surfaces respectively. For example, based on the test question positioning module 320, a pre-trained object detection algorithm or a preset test paper template may be used to identify question number features (such as symbols like "1. ", "1. " etc.) or question dividing lines in the image, so as to determine the coordinate range of each test question in the corresponding surface image. Subsequently, the image segmentation module 310 segments the surface image into a plurality of independent test question images according to the coordinate range, and each test question image corresponds to a separate question.

[0034] Then, for each segmented test question image, the control module may further distinguish between the question stem content in the test question image and the student's answer content to the test question. For example, the control module may perform the distinction based on grayscale features or color features of pixels. For instance, the printed question stem is usually uniform pure black pixels, while the handwriting of the student's answer usually has ink depth changes or color differences (in addition, the ink color of a black gel pen is generally darker than the color of a normally printed question stem). As another example, the control module may also input the test question image into the OCR module 330, so as to distinguish between standard printed font in the font library and handwritten strokes based on the OCR module 330, or classify the text into question stem text and answer text according to the text content identified by the OCR module 330.

[0035] After acquiring the question stem text and the answer text, the control module may input the question stem text and the answer text together into the large language model 340. The large language model 340 may evaluate the answer text based on its pre-trained logical reasoning capability and preset prior knowledge. If the answer is wrong, the large language model 340 may not only output a logical label representing the grading result (such as a cross representing an error), but also output note information for guiding the student to correct errors, such as specific solution step prompts, analysis of error-prone knowledge points, or encouraging comments.

[0036] After generating the logical label and the note information, the control module may convert the logical label and the note information into correction content executable by the inkjet module 130. At this time, the control module may determine the position and area size of the blank area around the test question image according to the corresponding test question image. According to the size of the blank area, the control module performs typesetting processing on the note information output by the large language model 340, for example, setting the font size and calculating line break positions, so as to ensure that the annotation content can be completely filled in the blank area without covering the original question stem or answer handwriting. At the same time, the control module may select specific handwriting style data according to the user's pre-configuration (for example, a handwritten font library simulating the cursive writing of a real teacher).

[0037] Subsequently, the control module combines the layout position after typesetting with the selected handwriting style data to rasterize these vector-based logical labels and annotation information, transforming them into a set of pixels to be printed in the physical coordinate system of the paper to be corrected. Then, the control module can convert these pixel coordinates into nozzle numbers and trigger delay times used to control the on / off state of specific nozzles in the first inkjet mechanism 131 and the second inkjet mechanism 132, to accommodate the unidirectional continuous movement of the paper.

[0038] It is understood that the aforementioned logical labels and annotation information can be generated for each question, and the logical labels and annotation information for each question constitute the annotation information for that question. For both sides of the paper to be corrected, the pixel array formed by the annotation information for each question is the correction content that the first inkjet mechanism 131 and the second inkjet mechanism 132 need to print on the two surfaces of the paper respectively.

[0039] In summary, the embodiment provided in this specification places the double-sided inkjet module 130 downstream of the double-sided scanning module 120. Therefore, the paper only needs to move from one end to the other along the planar path to complete the scanning and correction, without the need for flipping or single-sided rescanning, which greatly improves the efficiency of paper correction. At the same time, neither the scanning module 120 nor the inkjet module 130 needs to include displacement elements. The scanning and correction of the entire page can be achieved simply by moving the paper. Therefore, the device occupies very little space and is easy to maintain.

[0040] For some embodiments described in this specification, please refer to Figure 4 Both the first inkjet mechanism 131 and the second inkjet mechanism 132 may include a mounting plate 410 and a plurality of printhead modules 420 that are staggered along the first direction and assembled on the mounting plate 410. The printhead module 420 includes a plurality of nozzles arranged along the first direction. The nozzles are used to print pixels. The first direction is perpendicular to the second direction and the third direction. The second direction is the paper surface direction when the paper to be corrected passes through the second gap along the preset transport path 140. The third direction is the movement direction of the paper to be corrected when it passes through the second gap along the preset transport path 140.

[0041] In other words, the second direction is the thickness direction perpendicular to the paper surface, the first direction can be one of the length and width directions of the paper, and the third direction can be the other of the length and width directions of the paper. Multiple printhead modules 420 can be staggered in the second and third directions, but can remain continuous in the first direction. That is, the pixels printed by multiple printhead modules 420 can be connected into a complete row of pixels in the first direction, and cover the length of the paper to be corrected in the first direction (and can exceed it by leaving a margin in case the paper deforms).

[0042] Furthermore, since job correction generally does not require extremely high image resolution, the printing accuracy of the nozzles can be set to sub-millimeter level. For example, the side length of each pixel can be between 0.1 and 1 millimeter. Based on this, the cost of manufacturing the printhead can be reduced, while also reducing the risk of nozzle clogging. In the above embodiment, neither the inkjet mechanism nor the printhead module 420 needs to move. Therefore, on the one hand, the printing speed is improved, and on the other hand, the complex guide rail and belt wear problems are eliminated. This allows the correction machine to complete the correction while the paper is in motion, improving the stability and processing efficiency of the equipment.

[0043] Further, please see Figure 5 This is a perspective view of the first inkjet mechanism 131 and the second inkjet mechanism 132 in a second direction, wherein the solid line portion of reference numeral 510 represents the printhead module of the first inkjet mechanism 131, and the dashed line portion of reference numeral 520 represents the printhead module of the second inkjet mechanism 132. It can be seen that in some embodiments of this specification, the projection of each printhead module 420 of the first inkjet mechanism 131 onto the mounting plate 410 of the second inkjet mechanism 132 along the second direction does not coincide with the projection of each printhead module 420 of the second inkjet mechanism 132.

[0044] It is understood that the first inkjet unit 131 is located above the paper, and the second inkjet unit 132 is located below the paper, with the two positioned opposite each other. By staggering their projected positions, it is ensured that when no paper passes through the second gap, the ink droplets ejected by the first inkjet unit 131 will not directly enter or drip into the nozzle of the second inkjet unit 132, and vice versa, thus avoiding cross-contamination of ink between the upper and lower inkjet units. Furthermore, it also prevents ink from being simultaneously sprayed onto one position on both sides, thus avoiding ink seepage through the paper and smudging other areas when paper passes through.

[0045] In some embodiments of this specification, the printhead module 420 may further include multiple inkjet valves, each corresponding to one of the multiple nozzles included in the printhead module 420. Each inkjet valve is connected to the end of its corresponding nozzle furthest from the preset transport path 140. Simultaneously, the inkjet module 130 may also include an ink tank and an ink guide channel. The ink tank holds ink, and one end of the ink guide channel is connected to the ink tank, while the other end is connected to the end of each inkjet valve in the first inkjet mechanism 131 furthest from its corresponding nozzle, and the end of each inkjet valve in the second inkjet mechanism 132 furthest from its corresponding nozzle. The control module can be configured to control the first inkjet mechanism 131 and the second inkjet mechanism 132 to print corresponding correction content on two surfaces of the paper to be corrected by controlling the opening and closing of each inkjet valve in the first inkjet mechanism 131 and the second inkjet mechanism 132.

[0046] The ink tank is connected to individually controlled inkjet valves on both sides of the inkjet mechanism via an ink guide channel. The control module only needs to send an electrical signal to the corresponding inkjet valve to achieve pixel printing at the corresponding position. The pipeline structure is simple, facilitating unified ink replenishment and hydraulic maintenance. Since batch correction tasks usually do not require multiple colors of ink, using the above mechanism can also reduce the user's operating and maintenance costs.

[0047] In some embodiments of this specification, the correction content consists of at least one pixel to be printed in the coordinate system of the paper to be corrected, and the inkjet module 130 is used to print pixels at each pixel of the correction content. The control module can be configured to determine the nozzle number and delay time corresponding to each pixel to be printed for each of the two surfaces of the paper to be corrected, based on the moving speed and position of the paper to be corrected, wherein the nozzle number is used to identify the nozzle in the inkjet module 130; after waiting for the delay time, the control module controls the nozzle corresponding to the nozzle number to print the pixel.

[0048] In other words, the control module does not need to generate a complete bitmap or vector file of the entire test paper. Instead, it can use a sparse matrix to indicate where the inkjet module 130 should print ink. Then, since the physical position of each nozzle in the width direction of the paper is fixed, the control module only needs to convert the planar coordinates of the marked content into the specific hardware number to be activated and the activation timing to control the inkjet mechanism to print the desired marked content on the paper.

[0049] For example, suppose the system determines that a red dot needs to be printed at coordinates (x=50mm, y=100mm) in the paper coordinate system, and the leading edge of the paper has just passed the inkjet module 130, with the paper's movement speed being a constant 100mm / s. Based on the horizontal position of x=50mm and a preset mapping relationship, the control module determines that this position corresponds to nozzle number 5; simultaneously, based on the vertical position of y=100mm, it calculates that the dot still needs to travel 100mm to reach the inkjet module 130, meaning the waiting time is 100 / 100 = 1 second. Therefore, the control module can set a 1-second timer, and after the 1-second delay, trigger nozzle number 5 to open its inkjet valve once.

[0050] By adopting this coordinate transformation-based point spraying logic, the above implementation method can greatly reduce the amount of data processing in the system, avoid the rendering process of huge image data, and improve the response speed of the device.

[0051] In some embodiments of this specification, the control module may be configured to send the surface image acquired by the first scanning mechanism 121 and the surface image acquired by the second scanning mechanism 122 to the server, so that the server determines the correction content corresponding to the two surfaces of the paper to be corrected based on the received surface images, and sequentially sends the pixel row to the control module for each pixel row of the correction content, wherein the pixel row includes at least one pixel arranged in a first direction. After receiving the next pixel row of the currently printed pixel row, the control module controls the paper feeding mechanism 110 to continue carrying the paper to be corrected a preset distance, and controls the inkjet module 130 to print the next pixel row, wherein the preset distance is the height of the pixel to be printed; if the next pixel row of the currently printed pixel row is not received, the control module controls the paper feeding mechanism 110 to pause carrying the paper to be corrected.

[0052] The server mentioned here can be a cloud server maintained by the equipment manufacturer or a computer device deployed in a local area network. After receiving the surface image, the server can obtain the correction content corresponding to N rows of pixels and then directly send the correction content for those N rows; alternatively, after determining the correction content corresponding to the complete paper to be corrected, the server can send the correction content (as mentioned earlier, this content can be sparse, i.e., only the pixels that need inkjet printing are sent, and other pixels are not printed by default) to the control module row by row. Based on this, the control module can control the paper to move forward while receiving the data corresponding to the correction content. If the network is smooth, the paper moves forward continuously and completes the printing; if network fluctuations cause the next row of data to not arrive in time, the control module can intercept the paper feeding action in time, making the paper stop in place and wait until the new data arrives before continuing to move and print. It can be seen that by sending and printing pixels row by row, the above embodiment can avoid the machine downtime caused by waiting for the entire image data, and greatly improve the correction efficiency while ensuring the continuity of correction.

[0053] Here's an example. Assume a paper moves longitudinally, and an inkjet module spans the paper, containing nozzles numbered 1 to 100. When the server identifies the exam paper, it finds a blank section at the top, where a cross is only needed on the 100th line. The top of this cross is located on the 100th line and requires printing from nozzles 45 and 55. The following 101st line requires printing from nozzles 46 and 54.

[0054] Therefore, during the process of sending sparse data line by line, the server does not need to send the first 99 lines of all zeros or blank data to the control module. Instead, it directly sends the first valid instruction, such as: 100, [45, 55], indicating that nozzles 44 and 55 in the 100th line need to print. After receiving this instruction, the control module knows that the first 99 lines are empty and directly controls the paper feeding mechanism to continuously move the paper forward for 100 pixel lines, without triggering inkjet printing. When the paper reaches the 100th line, the control module only activates the valves of nozzles 45 and 55, while the nozzles corresponding to the empty pixels in the remaining line that are not in this instruction remain closed by default. Then, if no subsequent pixel lines are received, no termination instruction is received (to indicate that there are no more pixel lines to follow), and the waiting time threshold is not reached (to avoid paper jams due to network fluctuations), the paper to be corrected can be temporarily stopped until at least one of the above conditions is met.

[0055] After issuing the first instruction, the server can continue to issue the next valid instruction: 101, [46, 54]. Upon receiving this, the control module can drive the paper forward one line and control nozzles 46 and 54 to spray ink at the corresponding positions. Similarly, if there is a network delay and the server has not yet issued the data for line 102, the control module can stop the paper feeding mechanism after completing the printing of line 101, causing the paper to remain stationary. The paper feeding mechanism will only be activated again after the network is restored and the control module successfully receives subsequent instructions, allowing the paper to advance one line and execute the next inkjet.

[0056] In some embodiments of this specification, for data interaction between the server and the device, the control module can also be configured to: send the surface images acquired by the first scanning mechanism 121 and the second scanning mechanism 122 to the server, so that the server determines at least one correction mark corresponding to the two surfaces of the paper to be corrected and the target position of each correction mark based on the received surface images, and sends the at least one correction mark and the target position of each correction mark to the control module. The control module determines the geometric drawing rule corresponding to each received correction mark according to a preset symbol library, and at the target position of each received correction mark, determines the pixel to be printed corresponding to the correction mark based on the corresponding geometric drawing rule, thereby determining the correction content corresponding to the two surfaces of the paper to be corrected. The symbol library is used to record the mapping relationship between correction marks and geometric drawing rules.

[0057] In other words, in another implementation, the server can avoid sending pixel matrix data to the control module and instead only send printing instructions. For example, the server can simply send the instruction "(120,200), wrong mark" to the control module. Upon receiving this instruction, the control module queries its locally stored symbol library to determine that the geometric drawing rule for a "wrong mark" is to draw two intersecting diagonal lines of a preset length along a preset angle. This allows it to generate the coordinates of the specific pixels covered by these two diagonal lines, which are then converted into nozzle numbers and delay times for printing. Based on this, the above implementation further reduces the amount of communication data between the end-to-end cloud and improves the overall smoothness of the correction system.

[0058] In some embodiments of this specification, the grading system may further include a paper feed buffer 150, a paper feed roller 111, and an output paper feed buffer 160. The paper feed buffer 150 is located at the starting end of the preset transport path 140 and is used to hold the paper to be graded. The paper feed roller 111 abuts against the surface of the paper held in the paper feed buffer 150 and is used to transport the paper held in the paper feed buffer 150 to the paper feeding mechanism 110 by friction. The output paper feed buffer 160 is located at the ending end of the preset transport path 140 and is used to hold the paper to be graded.

[0059] The input tray can be a paper feed tray in a batching system, while the paper feed roller 111 can serve as a friction-type paging mechanism located at one end of the input tray. It should be understood that the paper feed roller 111 can also be considered part of the paper feeding mechanism 110, for example... Figure 1 As shown, when a user places multiple stacked sheets of paper to be graded into the input tray, the paper feed roller 111 rotates. The roller 111 uses surface friction to separate the outermost sheet of paper and feeds it individually into the paper feeding mechanism 110 inside the grading system. This ensures that the papers can stably pass through the subsequent scanning and inkjet areas page by page. Based on this, users can load sheets of paper to be graded in batches at once, and the grading system can perform grading work continuously in batches, significantly reducing the user's workload.

[0060] In some embodiments of this specification, in the preset transport path 140, the length of the portion located between the first gap and the second gap is greater than the length of the paper to be corrected. The control module can be configured to: after the paper to be corrected carried by the paper feeding mechanism 110 passes through the first gap, control the paper feeding mechanism 110 to stop carrying the paper to be corrected; after determining the correction content corresponding to the two surfaces of the paper to be corrected, control the paper feeding mechanism 110 to continue carrying the paper to be corrected.

[0061] In the aforementioned structure, the scanning module 120 and the inkjet module 130 are physically spaced apart by a distance sufficient to accommodate an entire sheet of paper (generally, the distance should be greater than or equal to the length of the paper in the third direction). When the tail of the paper completely leaves the first gap of the scanning module 120, it means that the image of the entire sheet has been captured and sent to the server. At this point, the front of the paper has not yet touched the second gap of the inkjet module 130. Therefore, the control module can allow the paper to temporarily stop in this intermediate zone. After the server completes the grading calculation and sends the grading content to the local machine, the paper restarts and enters the inkjet module 130 (as mentioned earlier, the paper can also be controlled to move forward after receiving the first row of pixels, without waiting for the complete cloud image). Based on this, the control module can reserve time for the server (or the control module itself) to generate grading content, and ensure that the server can refer to the complete writing data of the paper when generating grading content, avoiding the problem of data processing not keeping up with the physical movement speed of the paper, as well as the problem of misjudgment of grading content caused by incomplete scanning, thus ensuring the accurate output of grading results.

[0062] It is worth noting that the interval between the scanning module 120 and the inkjet module 130 refers to the length of the preset transport path 140 along the distance from the first gap to the second gap. Therefore, if the preset transport path 140 is not a plane, but a curved surface, or even wavy (e.g., Figure 6 As shown, the wavy motion trajectory can be defined by the paper roller and the baffle) or a U-shaped surface, and the interval distance can be greater than the straight-line distance (Euclidean distance) between the first gap and the second gap.

[0063] It should be understood that in some cases, the actions or steps described in the claims can be performed in a different order than those in the embodiments and still achieve the desired results. Furthermore, the embodiments provided in this specification can be applied independently or in combination and integrated with each other; therefore, the technical details set forth in different embodiments can also be referenced to each other. This specification is intended to cover any variations, uses, or adaptations of this specification that follow the general principles of this specification and include common knowledge or customary technical means in the art not claimed in this specification.

Claims

1. A grading system, characterized in that, The grading system includes: A paper feeding mechanism is used to acquire the paper to be corrected and drive the paper to be corrected to move along a preset transport path. The scanning module includes a first scanning mechanism and a second scanning mechanism arranged opposite to each other. The preset transport path passes through a first gap between the first scanning mechanism and the second scanning mechanism. The first scanning mechanism and the second scanning mechanism are respectively used to acquire surface images of the two surfaces of the paper to be corrected passing through the first gap. An inkjet module is disposed downstream of the scanning module along the preset transport path, and includes a first inkjet mechanism and a second inkjet mechanism disposed opposite to each other. The preset transport path passes through a second gap between the first inkjet mechanism and the second inkjet mechanism. The first inkjet mechanism and the second inkjet mechanism are respectively used to print content on two surfaces of the paper to be corrected passing through the second gap. The control module is used to determine the correction content corresponding to the two surfaces of the paper to be corrected based on the surface images acquired by the first scanning mechanism and the second scanning mechanism, and to control the first inkjet mechanism and the second inkjet mechanism to print the corresponding correction content on the two surfaces of the paper to be corrected according to the transmission speed and position of the paper to be corrected.

2. The grading system according to claim 1, characterized in that, Both the first inkjet mechanism and the second inkjet mechanism include: Mounting plate; Multiple printhead modules are staggered along a first direction and assembled on the mounting plate. Each printhead module includes multiple nozzles arranged along the first direction. The nozzles are used to print pixels. The first direction is perpendicular to the second direction and the third direction. The second direction is the direction perpendicular to the paper surface when the paper to be corrected passes through the second gap along the preset transport path. The third direction is the movement direction of the paper to be corrected when it passes through the second gap along the preset transport path.

3. The grading system according to claim 2, characterized in that, The correction content consists of at least one pixel to be printed in the coordinate system of the paper to be corrected, and the inkjet module is used to print pixels at each pixel to be printed in the correction content.

4. The grading system according to claim 3, characterized in that, The control module is configured as follows: For each pixel to be printed on the two surfaces of the paper to be corrected, the nozzle number and delay time corresponding to the pixel to be printed are determined according to the transmission speed and position of the paper to be corrected. The nozzle number is used to identify the nozzle in the inkjet module. After waiting for the delay time, the nozzle corresponding to the nozzle number is controlled to print pixels.

5. The grading system according to claim 3, characterized in that, The control module is configured as follows: The surface images acquired by the first scanning mechanism and the surface images acquired by the second scanning mechanism are sent to the server, so that the server determines the correction content corresponding to the two surfaces of the paper to be corrected based on the received surface images, and sequentially sends the pixel row to the control module for each pixel row of the correction content, wherein the pixel row includes at least one pixel to be printed arranged in the first direction; After receiving the next pixel row of the currently printed pixel row, the paper feeding mechanism is controlled to continue carrying the paper to be corrected a preset distance, and the inkjet module is controlled to print the next pixel row, wherein the preset distance is the height of the pixel to be printed; If the next pixel line of the currently printed pixel line is not received, the paper feeding mechanism is controlled to pause the transport of the paper to be corrected.

6. The grading system according to claim 3, characterized in that, The control module is configured as follows: The surface images acquired by the first scanning mechanism and the surface images acquired by the second scanning mechanism are sent to the server, so that the server determines at least one correction mark corresponding to the two surfaces of the paper to be corrected and the target position of each correction mark based on the received surface images, and sends the at least one correction mark and the target position of each correction mark to the control module. According to a preset symbol library, the geometric drawing rule corresponding to each received correction mark is determined, and at the target position of each received correction mark, the corresponding pixel to be printed is determined based on the corresponding geometric drawing rule, so as to determine the correction content corresponding to the two surfaces of the paper to be corrected. The symbol library is used to record the mapping relationship between correction marks and geometric drawing rules.

7. The grading system according to claim 2, characterized in that, The projection of each printhead module of the first inkjet mechanism onto the mounting plate of the second inkjet mechanism along the second direction does not coincide with each printhead module of the second inkjet mechanism.

8. The grading system according to claim 2, characterized in that, Each printhead module also includes multiple inkjet valves, each of which corresponds to one of the multiple nozzles included in the printhead module. The inkjet valve is connected to the end of the corresponding nozzle that is away from the preset transport path. The inkjet module also includes: Ink tank, used to hold ink; The ink guide channel is connected at one end to the ink tank and at the other end to the end of each inkjet valve in the first inkjet mechanism that is away from the corresponding nozzle, and to the end of each inkjet valve in the second inkjet mechanism that is away from the corresponding nozzle. The control module is configured as follows: By controlling the opening and closing of each inkjet valve in the first inkjet mechanism and the opening and closing of each inkjet valve in the second inkjet mechanism, the first inkjet mechanism and the second inkjet mechanism are controlled to print the corresponding correction content on the two surfaces of the paper to be corrected.

9. The grading system according to claim 1, characterized in that, The grading system also includes: The paper feed buffer is located at the starting end of the preset transport path and is used to hold the paper to be corrected; The paper feed roller abuts against the surface of the paper contained in the paper feed buffer, and is used to transport the paper contained in the paper feed buffer to the paper feeding mechanism by friction. The paper output buffer compartment is located at the end of the preset transport path and is used to hold the paper to be corrected.

10. The grading system according to claim 1, characterized in that, In the preset transport path, the length of the portion located between the first gap and the second gap is greater than the length of the paper to be corrected. The control module is configured as follows: After the paper to be corrected carried by the paper feeding mechanism passes through the first gap, the paper feeding mechanism is controlled to stop carrying the paper to be corrected. After determining the correction content corresponding to the two surfaces of the paper to be corrected, the paper feeding mechanism is controlled to continue carrying the paper to be corrected.

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