A method, apparatus and storage medium for calibrating vertical spacing between different nozzles for a single pass printer

Abstract

The application discloses a vertical interval calibration method, device and storage medium for different nozzles of a SinglePass printer, and relates to the technical field of printing calibration. The vertical position data of at least two groups of ink nozzles is collected in real time through a sensor array. The actual vertical interval deviation value between adjacent ink groups of nozzles is calculated based on the data. The actual vertical interval deviation value is filtered according to a preset deviation threshold range, and a dynamic nozzle closing instruction set is generated. In the printing task execution process, the nozzles that exceed the deviation threshold range are dynamically closed according to the instruction set. Based on the distribution of the dynamically closed nozzles, the printing data mapping relationship is reconstructed, and the position calibration in the vertical direction is realized.

Description

Technical Field

[0001] This invention relates to the field of print calibration technology, and more specifically, to a method, apparatus, and storage medium for calibrating the vertical spacing between different printheads of a SinglePass printer. Background Technology

[0002] With the development of technology, SinglePass printers are widely used in various printing scenarios due to their high efficiency and speed. However, in actual applications, slight deviations in the installation position of the printhead often lead to problems such as misalignment of the printed images and ghosting, which seriously affect the print quality. Existing technologies usually reduce printhead position deviation by improving the machining accuracy of the printing press and the installation accuracy of the printhead. However, this method is not only costly, but also difficult to completely eliminate the deviation, resulting in unstable print quality.

[0003] To address this issue, this invention proposes a method for calibrating the vertical spacing between different printheads in a SinglePass printer. By introducing sensors and a control system, precise calibration of the vertical spacing between printheads is achieved, eliminating printing ghosting caused by printhead position deviations. Furthermore, by dynamically adjusting the number of closed nozzles, this technical solution can support printing tasks at any resolution, improving the stability and adaptability of print quality.

[0004] The technical problem to be solved by this invention is: how to calibrate the vertical spacing between different ink group printheads in a SinglePass printer in order to eliminate the printing ghosting problem caused by printhead position deviation. Summary of the Invention

[0005] In order to overcome the problems existing in the prior art, the present invention discloses a method, device and storage medium for calibrating the vertical spacing between different printheads of a SinglePass printer, which can effectively solve the above-mentioned problems.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A method for calibrating the vertical spacing between different printheads in a SinglePass printer includes the following steps:

[0008] The vertical position data of at least two ink nozzles are collected in real time using a sensor array.

[0009] Based on the vertical position data, the actual vertical spacing deviation between adjacent ink group printheads is calculated;

[0010] The actual vertical spacing deviation value is filtered according to the preset deviation threshold range to generate a dynamic nozzle closing instruction set;

[0011] During the execution of the printing task, the nozzles that exceed the deviation threshold range are dynamically closed according to the dynamic nozzle closing instruction set;

[0012] Based on the nozzle distribution after dynamic shutdown, the vertical position calibration is achieved by reconstructing the printing data mapping relationship.

[0013] Preferably, the nozzle vertical position data includes: printing a preset calibration pattern on the printing medium, the calibration pattern comprising solid line reference marks and multiple spaced dashed line marks;

[0014] Image data of the calibration pattern is acquired using an optical sensor, and information on the overlap between solid and dashed lines is extracted.

[0015] Based on the overlap information, the actual vertical offset of the nozzle is calculated, and the vertical position data of the nozzle is generated.

[0016] Preferably, the calibration pattern satisfies the following conditions:

[0017] Solid line reference marks are continuously distributed along the printing direction;

[0018] The dashed lines are arranged at preset resolution intervals, and each dashed line is marked with its corresponding vertical calibration value;

[0019] When a solid line completely coincides with a dashed line, the vertical offset compensation value of the current nozzle is determined based on the calibration value marked by the dashed line.

[0020] Preferably, the calculation of the actual vertical spacing deviation value includes: establishing a nozzle position coordinate system, converting the vertical position data of each group of nozzles into vector parameters in the coordinate system; using a multi-order polynomial fitting algorithm to interpolate the vector parameters of adjacent nozzles to generate a continuous spatial position relationship model; determining the maximum deviation region based on the curvature change points of the position relationship model, and correcting the calculation results with the vertical offset compensation value.

[0021] Preferably, the generation logic of the dynamic nozzle closing instruction set includes: dynamically adjusting the deviation threshold range according to the resolution requirements of the printing task; when the printing resolution is higher than the preset threshold, enabling an adaptive segmented filtering strategy to divide the deviation tolerance range according to the nozzle area; and making a batch closing decision for nozzle groups that continuously exceed the tolerance range.

[0022] Preferably, the dynamic shutdown operation includes: embedding a nozzle status flag bit in the print data stream, the flag bit containing a nozzle disable identifier and an alternative nozzle index; synchronizing the dynamic nozzle shutdown instruction set to the nozzle control module of the print engine via a real-time data bus; and applying a reverse voltage pulse to the drive signal corresponding to the disabled nozzle to achieve physical shutdown.

[0023] Preferably, the method for reconstructing the printing data mapping relationship includes: establishing a data compensation weight matrix between the nozzle disabled state and adjacent available nozzles; performing convolution resampling on the original printing data according to the weight matrix to generate a calibrated printing data stream; and introducing a phase compensation factor in the vertical direction to adjust the inkjet triggering timing of different ink groups.

[0024] Preferably, a vertical spacing calibration device for SinglePass printing includes: a sensor module configured to acquire a calibration test pattern printed by the printhead and extract spatial offset features; a real-time data processing unit configured to execute the steps of the calibration method described above; a nozzle control module configured to adjust the nozzle drive signal according to the calibration result; and a data reconstruction engine module configured to remap the printed data to available nozzles based on calibration parameters.

[0025] Preferably, the sensor module is a multispectral sensor module, comprising: an infrared light source array for auxiliary illumination to generate calibration patterns in the non-visible spectral range; a high-speed linear array CMOS sensor configured to capture inkjet trajectories at a sampling rate higher than the operating frequency of the printing engine; and a polarization filter assembly for eliminating the influence of reflections on the printing medium surface on the calibration data.

[0026] Preferably, a computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the calibration method described above.

[0027] Compared with existing technologies, the advantages of this invention are as follows: This invention collects vertical position data of the printhead using a sensor array, accurately calculates the actual vertical distance deviation between adjacent printheads, and generates a dynamic nozzle closing instruction set based on this deviation value according to a preset deviation threshold range. During the printing process, nozzles exceeding the deviation threshold range are dynamically closed to prevent them from participating in the printing process, thereby avoiding printing ghosting problems caused by nozzle position deviations. Furthermore, by printing a preset calibration pattern and using an optical sensor to collect pattern image data, the overlap information of solid and dashed lines is extracted, and then the printhead position deviation is calculated. The actual vertical offset of the nozzle is used to generate vertical position data for the nozzle. This calibration pattern design makes the calculation of nozzle offset more accurate, providing a data foundation for subsequent calibration operations. When calculating the actual vertical spacing deviation, a nozzle position coordinate system is established, the vertical position data of the nozzle is converted into vector parameters, and a multi-order polynomial fitting algorithm is used for interpolation calculation to generate a continuous spatial position relationship model. The maximum deviation area is determined based on the curvature change points of this model, and the calculation results are corrected using vertical offset compensation values ​​to improve the accuracy and reliability of deviation calculation. The dynamic nozzle closing command set is generated... The system dynamically adjusts the deviation threshold range based on the resolution requirements of the printing task. When the printing resolution exceeds the preset threshold, an adaptive segmented filtering strategy is activated. The deviation tolerance range is divided according to the nozzle area, and a batch shutdown decision is made for nozzle groups that continuously exceed the tolerance range. This dynamic adjustment and adaptive filtering strategy enables the calibration method to adapt to printing tasks with different resolutions, improving the stability and adaptability of print quality. The dynamic shutdown operation embeds nozzle status flag bits in the print data stream, including nozzle disable identifiers and alternative nozzle indices. The dynamic nozzle shutdown instruction set is synchronized to the nozzle control module of the printing engine through the real-time data bus. A reverse voltage pulse is applied to the drive signal corresponding to the disabled nozzle to achieve physical shutdown, ensuring the timeliness and effectiveness of the nozzle shutdown operation. Finally, based on the nozzle distribution after dynamic shutdown, the print data mapping relationship is reconstructed to achieve vertical position calibration. A data compensation weight matrix between the nozzle disable state and adjacent available nozzles is established. The original print data is convolved and resampled according to this weight matrix to generate a calibrated print data stream. A phase compensation factor is introduced in the vertical direction to adjust the inkjet triggering timing of different ink groups, further optimizing the printing effect. Attached Figure Description

[0028] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary. For those skilled in the art, other embodiments can be derived from the provided drawings without creative effort.

[0029] Figure 1 This is a diagram illustrating the steps of the method of the present invention;

[0030] Figure 2 This is a schematic diagram illustrating the vertical spacing calibration of the printer nozzles according to the present invention. Detailed Implementation

[0031] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0032] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions;

[0033] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0034] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] Example

[0036] A method for calibrating the vertical spacing between different printheads in a SinglePass printer includes the following steps:

[0037] The vertical position data of at least two ink nozzles are collected in real time using a sensor array.

[0038] Based on the vertical position data, the actual vertical spacing deviation between adjacent ink group printheads is calculated;

[0039] The actual vertical spacing deviation value is filtered according to the preset deviation threshold range to generate a dynamic nozzle closing instruction set;

[0040] During the execution of the printing task, the nozzles that exceed the deviation threshold range are dynamically closed according to the dynamic nozzle closing instruction set;

[0041] Based on the nozzle distribution after dynamic shutdown, the vertical position calibration is achieved by reconstructing the printing data mapping relationship.

[0042] The nozzle vertical position data includes: printing a preset calibration pattern on the printing medium, the calibration pattern comprising solid line reference marks and multiple spaced dashed line marks;

[0043] Image data of the calibration pattern is acquired using an optical sensor, and information on the overlap between solid and dashed lines is extracted.

[0044] Based on the overlap information, the actual vertical offset of the nozzle is calculated, and the vertical position data of the nozzle is generated.

[0045] The calibration pattern satisfies the following conditions:

[0046] Solid line reference marks are continuously distributed along the printing direction;

[0047] The dashed lines are arranged at preset resolution intervals, and each dashed line is marked with its corresponding vertical calibration value;

[0048] When a solid line completely coincides with a dashed line, the vertical offset compensation value of the current nozzle is determined based on the calibration value marked by the dashed line.

[0049] The calculation of the actual vertical spacing deviation value includes: establishing a nozzle position coordinate system, converting the vertical position data of each group of nozzles into vector parameters in the coordinate system; using a multi-order polynomial fitting algorithm to interpolate the vector parameters of adjacent nozzles to generate a continuous spatial position relationship model; determining the maximum deviation area based on the curvature change points of the position relationship model, and correcting the calculation results with the vertical offset compensation value.

[0050] The generation logic of the dynamic nozzle closing instruction set includes: dynamically adjusting the deviation threshold range according to the resolution requirements of the printing task; when the printing resolution is higher than the preset threshold, enabling an adaptive segmented filtering strategy to divide the deviation tolerance range according to the nozzle area; and making batch closing decisions for nozzle groups that continuously exceed the tolerance range.

[0051] The dynamic shutdown operation includes: embedding nozzle status flag bits in the print data stream, the flag bits containing a nozzle disable identifier and an alternative nozzle index; synchronizing the dynamic nozzle shutdown instruction set to the nozzle control module of the print engine via a real-time data bus; and applying a reverse voltage pulse to the drive signal corresponding to the disabled nozzle to achieve physical shutdown.

[0052] The method for reconstructing the printing data mapping relationship includes: establishing a data compensation weight matrix between the nozzle disabled state and adjacent available nozzles; performing convolution resampling on the original printing data according to the weight matrix to generate a calibrated printing data stream; and introducing a phase compensation factor in the vertical direction to adjust the inkjet triggering timing of different ink groups.

[0053] A vertical spacing calibration device for SinglePass printing includes: a sensor module configured to acquire a calibration test pattern printed by a printhead and extract spatial offset features; a real-time data processing unit configured to execute the steps of the calibration method described above; a nozzle control module configured to adjust the nozzle drive signal according to the calibration result; and a data reconstruction engine module configured to remap the printed data to available nozzles based on calibration parameters.

[0054] The sensor module is a multispectral sensor module, comprising: an infrared light source array for auxiliary illumination to generate calibration patterns in the non-visible spectral range; a high-speed linear CMOS sensor configured to capture inkjet trajectories at a sampling rate higher than the operating frequency of the printing engine; and a polarization filter assembly for eliminating the influence of reflections from the printing medium surface on the calibration data.

[0055] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the calibration method described above.

[0056] For specific implementation details, please refer to [link / reference]. Figure 1-2 A preset calibration pattern is printed on the printing medium. The calibration pattern includes solid reference marks and multiple spaced dashed marks. The solid reference marks are continuously distributed along the printing direction to ensure a stable reference during printing. The dashed marks are arranged at preset resolution intervals, such as one dashed mark every 0.1 mm or 0.2 mm. Each dashed mark is labeled with a corresponding vertical calibration value, such as a sequence of values ​​that increase or decrease sequentially starting from 0. These values ​​are used to determine the vertical offset compensation value of the printhead.

[0057] The calibration pattern can be designed as a long strip, with its length aligned with the printing direction and its width spanning the ink jet range of the printhead, in order to accurately capture the printhead's vertical offset. At the same time, the line widths of the solid and dashed lines should be moderate, ensuring both print clarity and facilitating accurate identification and data acquisition by the optical sensor.

[0058] Image data of the calibration pattern is acquired using an optical sensor. The optical sensor should have high resolution and high precision image capture capabilities to ensure that the image features of solid and dashed lines can be clearly obtained. For example, an industrial-grade optical sensor with a resolution of 1200 dpi or higher can be selected.

[0059] During the data acquisition process, the sensor needs to scan the calibration pattern at a stable rate and with precise positioning to avoid image distortion or blurring caused by sensor movement, which would affect the accuracy of subsequent data extraction. At the same time, the acquired image data is preprocessed, such as grayscale processing and noise filtering, to improve data quality.

[0060] To extract the overlap information between solid and dashed lines from the acquired image data, image processing algorithms, such as edge detection algorithms (Canny algorithm, etc.), can be used to identify the edge positions of solid and dashed lines. Then, the pixel offset between the two in the vertical direction is calculated and converted into the actual physical length offset, i.e., the actual vertical offset of the nozzle. For example, if the sensor resolution is 1200 dpi, then the physical length corresponding to each pixel is approximately 0.021 cm. The actual vertical offset can be obtained by multiplying the pixel offset by this conversion factor.

[0061] Based on the overlap between the solid and dashed lines, when the solid line completely overlaps with a certain dashed line, the calibration value marked by the dashed line is recorded and used as the vertical offset compensation value of the current nozzle. The compensation value will be used for subsequent vertical spacing deviation calculation and calibration.

[0062] Establish a printhead position coordinate system. Select a fixed reference point on the printing platform as the origin, usually the lower left or lower right corner of the printing platform. With the printing direction as the x-axis and the perpendicular to the printing direction as the y-axis, construct a two-dimensional plane coordinate system. Convert the vertical position data of each group of printheads into vector parameters in the coordinate system. The position of each printhead can be represented by a two-dimensional vector (x, y), where x represents the position of the printhead in the printing direction and y represents the position of the printhead in the vertical direction.

[0063] A multi-order polynomial fitting algorithm is used to interpolate the vector parameters of adjacent printheads. For example, a third- or fourth-order polynomial can be selected for fitting. Through the fitting algorithm, a continuous spatial positional relationship model is generated. This model can describe the positional change trend of adjacent printheads within the printing area, thus more accurately reflecting the actual situation of the vertical spacing between printheads. The multi-order polynomial fitting formula can be expressed as:

[0064] y = a0 + a1x + a2x² + a3x³ + … + anxⁿ

[0065] Where a0, a1, a2…an are polynomial coefficients, x is the position variable of the printhead in the printing direction, and y is the position of the printhead in the vertical direction.

[0066] The maximum deviation region is determined based on the curvature change points of the continuous spatial position relationship model. These curvature change points reflect the drastic degree of nozzle position change; regions with larger curvature indicate regions with larger vertical spacing deviations. After determining the maximum deviation region, the previously calculated vertical offset compensation value is substituted to correct the calculation results, yielding a more accurate actual vertical spacing deviation value. The correction formula can be expressed as:

[0067] Corrected actual vertical spacing deviation = Uncorrected deviation calculated by model + Vertical offset compensation value

[0068] The deviation threshold range can be dynamically adjusted according to the resolution requirements of the printing task. For example, when the printing task requires high resolution, such as 600 dpi and above, the deviation threshold range can be set to a narrower range, such as ±0.05 mm; while for low resolution printing tasks, such as 300 dpi and below, the deviation threshold range can be appropriately widened to about ±0.1 mm.

[0069] When the print resolution is higher than the preset threshold, an adaptive segmented filtering strategy is enabled. The deviation tolerance range is divided according to the nozzle area. For example, the print area is divided into multiple small blocks, and each small block corresponds to a deviation tolerance range. The tolerance range is dynamically adjusted according to the actual deviation of the nozzles in the area to achieve more accurate nozzle filtering.

[0070] Batch shutdown decisions are made for nozzle groups that continuously exceed the tolerance range. By analyzing the deviation distribution of nozzles, nozzle groups that continuously exceed the deviation threshold are identified. For example, if the deviation of 5 or 10 nozzles continuously exceeds the threshold, they are identified as a nozzle group. Batch shutdown decisions are made for the nozzles in the group to improve calibration efficiency and print quality.

[0071] An nozzle status flag is embedded in the print data stream. This flag contains a nozzle disable flag and an alternative nozzle index. When a nozzle needs to be closed, a disable flag is inserted at the corresponding position in the print data stream, and an alternative nozzle index is specified. This allows the print engine to adjust the nozzle drive signal according to the flag, thereby achieving dynamic nozzle closure.

[0072] The dynamic nozzle closing instruction set is synchronized to the nozzle control module of the printing engine via a real-time data bus, ensuring that the instruction set can be transmitted to the nozzle control module in a timely and accurate manner, so as to achieve real-time control of the nozzle.

[0073] A reverse voltage pulse is applied to the drive signal corresponding to the disabled nozzle to achieve physical shutdown. The parameters of the reverse voltage pulse should be designed according to the specific characteristics of the nozzle and the requirements of the drive circuit to ensure that the nozzle can be effectively shut down without affecting the operation of other normal nozzles.

[0074] Establish a data compensation weight matrix between the disabled state of the nozzle and the adjacent available nozzles. Based on the positional relationship of the nozzles and the inkjet characteristics, determine the compensation weight of the adjacent available nozzles for the disabled nozzle data. For example, the closer the available nozzle is to the disabled nozzle, the greater its compensation weight, and vice versa. The weight matrix can be represented as a two-dimensional matrix, with rows and columns corresponding to different nozzle positions, and matrix elements representing the corresponding compensation weights.

[0075] The original print data is convolved and resampled based on the weight matrix to generate a calibrated print data stream. The original print data is then combined with the weight matrix through convolution operations to achieve data redistribution and compensation. This allows the calibrated print data stream to adapt to the nozzle distribution after nozzles are disabled, ensuring the integrity and quality of the printed pattern.

[0076] A phase compensation factor is introduced in the vertical direction. The value of the phase compensation factor is calculated based on the vertical offset of the printheads of different ink groups and the inkjet triggering timing requirements. For example, if the printhead of a certain ink group is offset by a certain distance in the vertical direction, in order to ensure that its inkjet is accurately superimposed on the inkjet of other ink groups in the vertical direction, its inkjet triggering timing needs to be adjusted. The phase compensation factor can be used to describe the magnitude of this timing adjustment.

[0077] By adjusting the inkjet triggering sequence of different ink groups according to the phase compensation factor, and by precisely controlling the inkjet triggering time, the inkjet of each ink group can be precisely aligned in the vertical direction, thereby improving the printing quality and avoiding problems such as pattern misalignment or ghosting caused by vertical spacing deviation of the printhead.

[0078] Infrared light source arrays are used as auxiliary illumination to generate calibration patterns in the non-visible spectrum range. Their advantage is that infrared light does not interfere with the imaging effect of visible ink on the printing medium, while providing sufficient illumination for optical sensors, improving the clarity and stability of image acquisition. The infrared light source array can be composed of multiple infrared light-emitting diodes (IR LEDs) evenly distributed around the sensor to ensure uniform illumination of the calibration pattern area.

[0079] The high-speed linear CMOS sensor is configured to capture inkjet trajectories at a sampling rate higher than the operating frequency of the print engine. For example, if the operating frequency of the print engine is 10kHz, the sampling rate of the high-speed linear CMOS sensor can be set to 20kHz or higher to ensure accurate capture of subtle changes and printhead position information during the inkjet process. The sensor has high sensitivity and fast response characteristics, and can acquire inkjet trajectory data in real time during the printing process and convert it into digital image signals to provide accurate raw data for subsequent data processing.

[0080] Polarizing filters are used to eliminate the influence of reflections from the printing medium on calibration data. During the printing process, the surface of the printing medium may generate interference light due to light reflection, which affects the accurate acquisition of the calibration pattern by the optical sensor. Polarizing filters can make the polarization direction of the reflected light perpendicular to the polarization direction of the light received by the sensor, thereby effectively filtering out reflected light, improving image quality, and ensuring the reliability of calibration data.

[0081] The real-time data processing unit can use a high-performance embedded processor or FPGA (Field Programmable Gate Array) as the core processing chip. Embedded processors have software programmability and rich peripheral interfaces, which facilitates the implementation of complex algorithm processing and communication with other modules; FPGAs have high-speed parallel processing capabilities and hardware-level reliability, making them suitable for data processing tasks with extremely high real-time requirements.

[0082] The software functions include a data acquisition driver module, which is responsible for communicating with the multispectral sensor module, controlling the sensor's data acquisition process, and reading the acquired raw data into the processing unit's memory.

[0083] The data preprocessing module performs operations such as filtering, noise reduction, and grayscale processing on the raw data to improve data quality.

[0084] The vertical spacing deviation calculation module, based on the calculation steps in the above calibration method, realizes functions such as establishing the printhead position coordinate system, applying multi-order polynomial fitting algorithms, determining and correcting the maximum deviation region, and calculates the actual vertical spacing deviation value between adjacent ink group printheads.

[0085] The nozzle closing instruction generation module generates a dynamic nozzle closing instruction set based on the deviation threshold range and nozzle deviation, and embeds it into the print data stream.

[0086] The print data reconstruction module establishes a data compensation weight matrix, performs convolutional resampling, and introduces a phase compensation factor to adjust the inkjet trigger timing, thereby reconstructing the print data mapping relationship.

[0087] The nozzle control module includes a nozzle drive circuit, which is used to adjust the nozzle drive signal according to the calibration results. The drive circuit should have high-precision signal control capability and be able to accurately control the on / off of the drive signal and voltage pulse parameters of each nozzle according to the dynamic nozzle closing instruction set. For example, a digital-to-analog converter (DAC) is used to convert the digital instruction signal into an analog voltage signal to accurately control the nozzle drive voltage and pulse width.

[0088] To achieve physical-level shut-off of the nozzles, the nozzle control module is designed with a reverse voltage pulse generation circuit. After receiving the nozzle shut-off command, this circuit can quickly generate a reverse voltage pulse of appropriate amplitude and width, which is applied to the driving electrode corresponding to the disabled nozzle. This causes the driving elements such as piezoelectric crystals or thermistors inside the nozzle to undergo reverse deformation or temperature change, thereby preventing ink from being ejected and achieving nozzle shut-off.

[0089] The data reconstruction engine module includes a data caching and management unit, which is used to temporarily store the original print data and the calibrated print data stream. The caching unit should have sufficient storage capacity and fast data read and write capabilities to meet the real-time storage and retrieval requirements of data during the printing process. At the same time, the data management unit is responsible for organizing and managing the cached data to ensure the integrity and consistency of the data.

[0090] The data remapping and compensation unit remaps and compensates the original print data according to the calibration parameters and weight matrix. This unit uses a convolution algorithm to redistribute the data, adjusts the original data according to the new nozzle distribution and compensation weight, and generates a calibrated print data stream. At the same time, it adjusts the inkjet triggering timing of different ink groups according to the phase compensation factor to ensure accurate alignment of the print data in the vertical direction.

[0091] In this example, the computer-readable storage medium can be a flash memory, hard disk, optical disk, or other medium capable of storing computer programs. The computer program stored in the medium contains a series of instructions that, when executed by a processor, can implement the various steps of the above calibration method. The program adopts a modular design, including a data acquisition module, a deviation calculation module, a nozzle control module, a data reconstruction module, etc., which works closely with the hardware architecture of the calibration equipment to ensure the efficient execution and accurate implementation of the calibration method.

[0092] The same or similar labels correspond to the same or similar parts;

[0093] The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0094] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A method for calibrating the vertical spacing between different printheads in a SinglePass printer, characterized in that, Includes the following steps: The vertical position data of at least two ink nozzles are collected in real time using a sensor array. Based on the vertical position data, the actual vertical spacing deviation between adjacent ink group printheads is calculated; The actual vertical spacing deviation value is filtered according to a preset deviation threshold range to generate a dynamic nozzle closing instruction set; the preset deviation threshold range is a deviation threshold range that is dynamically adjusted according to the resolution requirements of the printing task. During the execution of the printing task, the nozzles that exceed the deviation threshold range are dynamically closed according to the dynamic nozzle closing instruction set; Based on the nozzle distribution after dynamic closure, the vertical position calibration is achieved by reconstructing the print data mapping relationship. The method for reconstructing the printing data mapping relationship includes: establishing a data compensation weight matrix between the nozzle disabled state and adjacent available nozzles; performing convolution resampling on the original printing data according to the weight matrix to generate a calibrated printing data stream; and introducing a phase compensation factor in the vertical direction to adjust the inkjet triggering timing of different ink groups.

2. The calibration method according to claim 1, characterized in that, The nozzle vertical position data includes: A preset calibration pattern is printed on a printing medium, the calibration pattern comprising solid line reference marks and multiple spaced dashed line marks; Image data of the calibration pattern is acquired using an optical sensor, and information on the overlap between solid and dashed lines is extracted. Based on the overlap information, the actual vertical offset of the nozzle is calculated, and the vertical position data of the nozzle is generated.

3. The calibration method according to claim 2, characterized in that, The calibration pattern satisfies the following conditions: Solid line reference marks are continuously distributed along the printing direction; The dashed lines are arranged at preset resolution intervals, and each dashed line is marked with its corresponding vertical calibration value; When a solid line completely coincides with a dashed line, the vertical offset compensation value of the current nozzle is determined based on the calibration value marked by the dashed line.

4. The calibration method according to claim 1, characterized in that, The calculation of the actual vertical spacing deviation value includes: Establish a nozzle position coordinate system and convert the vertical position data of each group of nozzles into vector parameters in the coordinate system; A multi-order polynomial fitting algorithm is used to interpolate the vector parameters of adjacent nozzles to generate a continuous spatial positional relationship model. The maximum deviation region is determined based on the curvature change points of the positional relationship model, and the calculation results are corrected using the vertical offset compensation value.

5. The calibration method according to claim 1, characterized in that, The generation logic for the dynamic nozzle closing instruction set includes: When the print resolution is higher than the preset threshold, the adaptive segmented filtering strategy is enabled, and the deviation tolerance range is divided according to the nozzle area. Make batch shutdown decisions for nozzle groups that continuously exceed the tolerance range.

6. The calibration method according to claim 1, characterized in that, The dynamic shutdown operation includes: Embed nozzle status flag bits in the print data stream; the flag bits include a nozzle disabled flag and an alternative nozzle index. The dynamic nozzle closing instruction set is synchronized to the nozzle control module of the printing engine via a real-time data bus. A reverse voltage pulse is applied to the drive signal corresponding to the disabled nozzle to achieve physical-level shutdown.

7. A vertical spacing calibration device for SinglePass printing, characterized in that, include: The sensor module is configured to acquire calibration test patterns printed by the nozzle and extract spatial offset features; A real-time data processing unit configured to perform the steps of the calibration method according to any one of claims 1-6; The nozzle control module is configured to adjust the nozzle drive signal according to the calibration results; The data reconstruction engine module is configured to remap print data to available nozzles based on calibration parameters.

8. The calibration device according to claim 7, characterized in that, The sensor module is a multispectral sensor module, comprising: An infrared light source array is used as auxiliary illumination to generate calibration patterns in the non-visible spectrum. A high-speed linear CMOS sensor is configured to capture inkjet trajectories at a sampling rate higher than the operating frequency of the print engine; A polarizing filter assembly is used to eliminate the influence of reflections from the printing medium surface on calibration data.

9. A computer-readable storage medium storing a computer program, characterized in that, When the program is executed by the processor, it implements the steps of the calibration method according to any one of claims 1-6.

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