An inkjet printing image misregistration compensation method, system, device and storage medium

Abstract

The present application relates to the field of inkjet printing technology, and discloses an inkjet printing image offset compensation method, system, device and storage medium, comprising collecting base plane vibration signals by using a vibration detection sensor; amplifying and filtering the base plane vibration signals by using a conditioning device to obtain a boosted electrical signal; performing frequency domain expansion compensation on the boosted electrical signal to obtain a frequency-expanded electrical signal; controlling the inkjet platform to collect the frequency-expanded electrical signal from the conditioning device and extract spatial coordinate parameters and time parameters from the frequency-expanded electrical signal; determining a target printing image from a pre-set printing image library based on the time parameters; and performing offset compensation on the target printing image based on the spatial coordinate parameters to obtain a compensated printing image; the present application corrects the spatial position offset of the pixel slot caused by vibration, so that the ink drop ejection landing point is accurately aligned with the pixel slot, effectively solving the printing offset problem caused by low-frequency vibration of the base plane.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of inkjet printing technology, and in particular to an inkjet printing image offset compensation method, system, device and storage medium. BACKGROUND

[0002] OLED inkjet printing technology has become one of the core technologies for manufacturing large-size and high-resolution display devices due to its significant advantages in film thickness uniformity, high-resolution pattern, and material utilization. However, as the size of glass substrates expands to larger specifications, the overall volume and weight of inkjet printing equipment also increase accordingly. The micro-low-frequency vibration of the base plane cannot be completely eliminated and is affected by the production workshop environment. This vibration is transmitted to the substrate and causes random disturbances in three-dimensional space, resulting in a shift in the pixel slot position on the substrate, which in turn causes ink drop landing point deviation, severely affecting printing accuracy, and even causing ink drops to deviate from the pixel slot. Therefore, how to reduce the impact of low-frequency vibration of the base plane on inkjet printing landing accuracy has become a key issue for improving the quality of OLED inkjet printing. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide an inkjet printing image offset compensation method, system, device and storage medium. The present application specifically corrects the spatial position shift of the pixel slot caused by vibration, aligns the ink drop ejection landing point with the pixel slot accurately, effectively solves the printing offset problem caused by low-frequency vibration of the base plane, and significantly improves the landing accuracy and image quality of inkjet printing.

[0004] The first aspect of the present application provides an inkjet printing image offset compensation method applied to an inkjet printing image offset compensation system, wherein the inkjet printing image offset compensation system comprises a control device, a vibration detection sensor, a conditioning device and a printing platform electrically connected to the control device; the inkjet printing image offset compensation method comprises the following steps:

[0005] The vibration detection sensor is used to collect the base plane vibration signal and transmit the base plane vibration signal to the conditioning device;

[0006] The conditioning device is used to amplify and filter the base plane vibration signal to obtain a boosted electrical signal;

[0007] The conditioning device is used to perform frequency domain expansion compensation on the boosted electrical signal to obtain a frequency-expanded electrical signal;

[0008] The printing platform is used to collect the frequency-expanded electrical signal from the conditioning device and extract spatial coordinate parameters and time parameters from the frequency-expanded electrical signal;

[0009] A target printing image is determined from a pre-set printing image library based on the time parameter;

[0010] The target printing image is offset compensated based on the spatial coordinate parameters to obtain a compensated printing image.

[0011] Optionally, in the first implementation manner of the first aspect, the collecting the base plane vibration signal by using the vibration detection sensor and transmitting the base plane vibration signal to the conditioning device comprises: arranging the vibration detection sensor on the base plane where the jet printing platform is located; collecting the physical vibration of the base plane by using the vibration detection sensor and converting the vibration amount into an electrical signal to obtain the base plane vibration signal; the amplitude of the base plane vibration signal is proportional to the physical displacement amount of the base plane vibration; and transmitting the base plane vibration signal to the conditioning device.

[0012] Optionally, in the second implementation manner of the first aspect, the amplifying and filtering the base plane vibration signal by using the conditioning device to obtain the boosted electrical signal comprises: the conditioning device comprises an amplification module, a low-pass filtering module and a high-pass filtering module; the base plane vibration signal is linearly amplified by the amplification module to raise the signal amplitude to a preset standard voltage range to form an amplified signal; the preset high-frequency threshold signal is filtered out from the amplified signal by using the low-pass filtering module to obtain a low-pass processed signal; and the preset low-frequency threshold is filtered out from the low-pass processed signal by using the high-pass filtering module to obtain the boosted electrical signal.

[0013] Optionally, in the third implementation manner of the first aspect, the frequency domain expansion compensation of the boosted electrical signal by using the conditioning device to obtain the frequency-expanding electrical signal comprises: the conditioning device comprises a frequency domain detection module and a second-order filtering module; the effective frequency domain range of the boosted electrical signal is determined by using the frequency domain detection module; and if the effective frequency domain range does not completely cover the preset base plane vibration compensation frequency, the frequency domain expansion processing of the boosted electrical signal is performed by using the second-order filtering module to obtain the frequency-expanding electrical signal.

[0014] Optionally, in the fourth implementation manner of the first aspect, the controlling the jet printing platform to collect the frequency-expanding electrical signal from the conditioning device and extracting the spatial coordinate parameters and the time parameters from the frequency-expanding electrical signal comprises: controlling the jet printing platform to collect the frequency-expanding electrical signal from the conditioning device; mapping the corresponding vibration displacement amount in the frequency-expanding electrical signal to the z-axis parameter in the spatial coordinate, and mapping the spatial positions of the vibration detection sensors on the base plane to the x-axis parameter and the y-axis parameter to form the spatial coordinate parameters; and recording the time information of each time of collecting the frequency-expanding electrical signal to generate the time parameters corresponding to the spatial coordinate parameters.

[0015] Optionally, in a fifth implementation form of the first aspect of the present application, the determining the target printing image from the preset printing image library based on the time parameter comprises: establishing a mapping relationship between the time parameter and the printing image ejection sequence number, so that each time parameter is matched to a unique printing image ejection sequence number; and searching for the corresponding printing image from the preset printing image library by taking the printing image ejection sequence number as an index, and determining the searched printing image as the target printing image.

[0016] Optionally, in a sixth implementation form of the first aspect of the present application, the offset compensation of the target printing image based on the spatial coordinate parameter to obtain a compensated printing image comprises: obtaining historical spatial coordinate parameters, and generating a coordinate array based on the historical spatial coordinate parameters and the spatial coordinate parameter; calculating a Cartesian coordinate parameter from the coordinate array by using an orthogonal mapping method; converting the Cartesian coordinate parameter into a polar coordinate parameter by using a coordinate system conversion method; the polar coordinate parameter comprises an offset distance and a rotation angle; and offset compensating the target printing image based on the offset distance and the rotation angle to obtain the compensated printing image.

[0017] The second aspect of the present application provides a system for offset compensation of an inkjet printing image, which comprises a control device, and a vibration detection sensor, a conditioning device and a printing platform electrically connected to the control device; the control device is used to execute any of the above-mentioned inkjet printing image offset compensation methods.

[0018] The third aspect of the present application provides an inkjet printing image offset compensation device, which comprises a memory and at least one processor, and the memory stores instructions; the at least one processor calls the instructions in the memory, so that the computer device executes each step of the above-mentioned inkjet printing image offset compensation method.

[0019] The fourth aspect of the present application provides a computer readable storage medium, which stores instructions, and the instructions are executed by a processor to realize each step of the above-mentioned inkjet printing image offset compensation method.

[0020] In the technical solution of the present application, firstly, the base plane vibration signal is collected in real time through the vibration detection sensor, and then the base plane vibration signal is amplified, filtered and frequency domain expanded and compensated by the conditioning device to form a frequency expansion electrical signal covering the vibration frequency range; subsequently, the frequency expansion electrical signal is collected by the jet printing platform, and the corresponding spatial coordinate parameters and time parameters are extracted, which not only determines the three-dimensional offset state of the substrate caused by vibration, but also realizes the matching of vibration information and printing timing; then, the target printing image is located from the to-be-printed image library based on the time parameter, and the target printing image is offset compensated combined with the spatial coordinate parameters, and finally the compensated printing image is obtained; the present application corrects the spatial position offset of the pixel slot caused by vibration, so that the ink drop ejection landing point is accurately aligned with the pixel slot, effectively solves the printing offset problem caused by low-frequency vibration of the base plane, and significantly improves the landing point precision and image quality of inkjet printing. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0022] Figure 1 The first flow chart of the inkjet printing image offset compensation method provided by the embodiment of the present application;

[0023] Figure 2 The second flow chart of the inkjet printing image offset compensation method provided by the embodiment of the present application;

[0024] Figure 3 The third flow chart of the inkjet printing image offset compensation method provided by the embodiment of the present application;

[0025] Figure 4 The fourth flow chart of the inkjet printing image offset compensation method provided by the embodiment of the present application;

[0026] Figure 5 The fifth flow chart of the inkjet printing image offset compensation method provided by the embodiment of the present application;

[0027] Figure 6 The sixth flow chart of the inkjet printing image offset compensation method provided by the embodiment of the present application;

[0028] Figure 7 The seventh flow chart of the inkjet printing image offset compensation method provided by the embodiment of the present application;

[0029] Figure 8 The structure schematic diagram of the inkjet printing image offset compensation system provided by the embodiment of the present application;

[0030] Figure 9 The structure schematic diagram of the inkjet printing image offset compensation device provided by the embodiment of the present application;

[0031] Figure 10 A structure schematic view of a vibration detection sensor and a carrier platform provided by an embodiment of the present application is shown in the figure;

[0032] Figure 11 A top view of a vibration detection sensor and a carrier platform provided by an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0033] The present application provides an inkjet printing image offset compensation method, system, device and storage medium, which specifically corrects the pixel slot space position offset caused by vibration, so that the ink drop ejection landing point is accurately aligned with the pixel slot, effectively solves the printing offset problem caused by low-frequency vibration of the base plane, and significantly improves the landing point accuracy and image quality of inkjet printing.

[0034] The terms "first", "second", "third", "fourth" and the like in the description, claims, and drawings of the present application, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of these terms herein is to be construed as interchangeable in order to distinguish between the similar objects. It is also to be understood that the terms "comprising", "having", "including" and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. It is intended that the application encompass the following embodiments and / or claims.

[0035] For the convenience of understanding, the specific flow of the embodiment of the present application is described below, please refer to Figure 1 An embodiment of the inkjet printing image offset compensation method in the embodiment of the present application includes:

[0036] The inkjet printing image offset compensation system includes:

[0037] The base plane is a bearing surface for storing the OLED inkjet printing device, such as the workshop ground plane, the industrial machine tool bearing table, etc., which needs to have the physical properties of flat surface and strong stiffness characteristics to ensure that it can stably bear the printing platform, vibration detection sensor and other entities; the base plane is the installation reference and vibration transmission carrier of the whole system, and the slight low-frequency vibration in the workshop environment will be transmitted to the printing platform above through the base plane, and then drive the glass substrate on the printing platform to produce spatial offset, which is the source transmission medium of the vibration signal;

[0038] The vibration detection sensor is a passive device that detects weak, low-frequency vibrations of the base plane. Its output signal is a weak electrical signal (requiring processing by a conditioning device). The specific number deployed depends on the printing scenario and compensation algorithm requirements. The vibration detection sensor can capture the physical vibration of the base plane in real time, converting the vibration (displacement of the base plane along the z-axis) into a transmittable base plane vibration signal, which is then transmitted to the conditioning device to provide raw data for subsequent signal processing. The vibration detection sensor is electrically connected to the conditioning and control devices via a network cable.

[0039] The conditioning device includes an amplification module, a low-pass filter module, a high-pass filter module, a frequency domain detection module, and a second-order filter module. The conditioning device may include multiple independent parallel conditioning circuits, each corresponding to a vibration detection sensor. The core function of the conditioning device is to process the weak electrical signal output by the vibration detection sensor. First, the amplification module amplifies the weak plane vibration signal output by the vibration detection sensor. Then, the low-pass and high-pass filter modules filter out interference to obtain a boosted electrical signal. Finally, the frequency domain detection and second-order filter modules perform frequency domain extension compensation to output a frequency-extended electrical signal, solving the problems of the original signal being "weak, noisy, and incomplete in the frequency domain." The conditioning device is electrically connected to the vibration detection sensor, the printing platform, and the control device via a network cable.

[0040] The inkjet printing platform is an integrated execution unit, including a platform, printhead drive board, printhead, and ink circulation system. The platform simultaneously performs signal acquisition, parameter extraction, image matching, and offset compensation. It first acquires the frequency-modulated electrical signal output from the conditioning device, extracting spatial coordinate parameters (x, y, and z-axis parameters corresponding to vibration) and time parameters. Then, based on the time parameters, it determines the target image from a preset image library. Finally, it performs offset compensation on the target image based on the spatial coordinate parameters, generating a compensated print image. Simultaneously, inkjet printing is completed via the printhead drive board and printhead, with the ink circulation system ensuring ink supply. The printing platform is electrically connected to the conditioning and control devices via a network cable. The platform is mounted on a base plane, with a glass substrate fixed to its top surface. The printhead drive board connects to the printhead, and the ink circulation system supplies ink to the printhead.

[0041] The control device uses an industrial-grade embedded controller to control the working timing of each entity on the base plane. Specific functions include: sending "start / stop acquisition" commands to the vibration detection sensor to control its operating status; sending signal processing parameters (such as amplification factor, filtering threshold, and frequency domain extension range) to the conditioning device to ensure that the conditioning device outputs a frequency-spreading electrical signal that meets the requirements; sending "signal acquisition trigger," "image compensation command," and "printhead drive parameters" to the printing platform to synchronously control signal acquisition, image processing, and printing execution; receiving status signals from each entity (such as sensor failure, conditioning device signal abnormality, and printing platform compensation completion) and displaying the system status through a human-machine interface; the control device is electrically connected to the printing platform, conditioning device, and vibration detection sensor via a network cable.

[0042] The specific workflow of the inkjet printing image offset compensation system is as follows:

[0043] After the base plane generates a small low-frequency vibration due to the workshop environment, the control device sends a collection command to the vibration detection sensor. The vibration detection sensor deployed under the platform synchronously captures the physical vibration of the base plane, converts the vibration into a weak base plane vibration signal (mV level signal), and transmits the signal to the conditioning device through the network cable.

[0044] After receiving the base plane vibration signal, the conditioning device first linearly amplifies the weak signal (up to V-level signal) through an internal amplification module. Then, it filters out the preset high-frequency threshold signal (cutoff bandwidth of 1000Hz) through a low-pass filter module and filters out the preset low-frequency threshold signal (cutoff bandwidth of 10Hz) through a high-pass filter module, resulting in a boosted electrical signal. Subsequently, the effective frequency domain range of the boosted electrical signal is detected by a frequency domain detection module. If the range does not completely cover the preset base plane vibration compensation frequency (extended from 10Hz downward to 0.5Hz or from 10Hz upward to 1000Hz), the frequency domain is extended through a second-order filter module to finally generate a frequency-extended electrical signal, which is then ready for the printing platform to collect.

[0045] The control device sends a command to the printing platform to acquire the superposition electrical signal. After acquiring the superposition electrical signal from the conditioning device, the printing platform analyzes the physical state corresponding to the vibration based on the signal: it maps the vibration displacement in the superposition electrical signal to the z-axis parameter of the spatial coordinate parameters, and maps the fixed position of the vibration detection sensor on the base plane to the x-axis and y-axis parameters of the spatial coordinate parameters, forming the spatial coordinate parameters [xn, yn, zn]; at the same time, it records the time information of this acquisition of the superposition electrical signal and generates the time parameter tn corresponding to the spatial coordinate parameters.

[0046] Based on the extracted time parameter tn, the printing platform queries the preset mapping relationship of "time parameter - print sequence number of image to be printed" so that tn matches a unique print sequence number of the image to be printed; then, using the print sequence number as an index, it retrieves the corresponding image to be printed from the preset image library built into the printing platform and identifies it as the target image to be printed.

[0047] The printing platform performs offset compensation on the target print image determined in the image library based on the extracted spatial coordinate parameters: First, it obtains historical spatial coordinate parameters and generates a coordinate array (containing past positions and current displacement states) together with the current spatial coordinate parameters; Cartesian coordinate parameters are calculated from the coordinate array using an orthogonal mapping method (mapping the tilted glass substrate to an absolute horizontal plane), and then the Cartesian coordinate parameters are converted into polar coordinate parameters containing offset distance and rotation angle using a coordinate system transformation method; finally, pixel-level offset compensation is performed on the target print image based on the offset distance and rotation angle to obtain the compensated print image; after compensation, the printing platform drives the printhead through the printhead driver board, and in conjunction with the circulating ink path system, ejects ink droplets onto the glass substrate fixed on the platform to complete the compensated inkjet printing.

[0048] The inkjet printing image offset compensation method includes the following steps:

[0049] 101. Use a vibration detection sensor to collect the vibration signal of the base plane and transmit the vibration signal of the base plane to the conditioning device;

[0050] In this embodiment, vibration detection sensors are deployed on the base plane directly below the four corners of the printing platform. The vibration detection sensors capture the tiny low-frequency vibrations of the base plane in real time, convert the physical vibration into base plane vibration signals with an intensity of mV, and then transmit the signals to the conditioning device to provide raw vibration data for subsequent processing.

[0051] 102. The vibration signal of the base plane is amplified and filtered using a conditioning device to obtain a boosted electrical signal;

[0052] In this embodiment, the conditioning device linearly amplifies the mV-level base plane vibration signal to the V-level standard voltage range through an internal amplification module, and then sequentially passes it through a low-pass filter module and a high-pass filter module to remove noise components from the signal, finally obtaining a boosted electrical signal.

[0053] 103. Use a conditioning device to perform frequency domain extension compensation on the boosted electrical signal to obtain a frequency-extended electrical signal;

[0054] In this embodiment, the frequency domain detection module of the conditioning device first analyzes the effective frequency domain range of the boosted electrical signal. If it finds that the preset base plane vibration compensation frequency is not fully covered, the signal is extended in the frequency domain by the second-order filtering module to fill in the uncovered frequency range, and finally outputs a frequency-extended electrical signal that covers the full compensation frequency and maintains the intensity level V.

[0055] 104. Control the printing platform to collect the frequency conversion electrical signal from the conditioning device, and extract the spatial coordinate parameters and time parameters from the frequency conversion electrical signal;

[0056] In this embodiment, the printing platform acquires the topology electrical signal at a sampling frequency adapted to the ink droplet ejection frequency; and maps the signal into spatial coordinate parameters according to the linear relationship between the signal amplitude and vibration displacement, while recording the time information of each acquisition and generating time parameters corresponding to the spatial coordinate parameters.

[0057] 105. Determine the target image to be printed from a preset image library based on time parameters;

[0058] In this embodiment, the printing platform establishes a mapping relationship between the time parameters and the inkjet serial number of the image to be printed. Using the inkjet serial number of the image to be printed as an index, the corresponding image to be printed is quickly retrieved from the preset image library and identified as the target image to be compensated.

[0059] 106. Perform offset compensation on the target printed image based on spatial coordinate parameters to obtain a compensated printed image;

[0060] In this embodiment, the printing platform integrates the current and historical spatial coordinate parameters to generate a coordinate array, then uses the orthogonal mapping method to convert the tilted coordinate array into Cartesian coordinate parameters, and then uses the coordinate system transformation method to convert it into polar coordinate parameters containing offset distance and rotation angle; subsequently, based on the offset distance and rotation angle, all pixels of the target printed image are offset and rotated to correct, and finally a compensated printed image is generated.

[0061] In this embodiment of the invention, vibration signals of the base plane are first acquired in real time using a vibration detection sensor. Then, the vibration signals are amplified, filtered, and frequency-domain extended compensationd using a conditioning device to form an extended frequency electrical signal covering the vibration frequency range. Subsequently, the extended frequency electrical signal is acquired using a printing platform, and the corresponding spatial coordinate parameters and time parameters are extracted. This clarifies the three-dimensional offset state of the substrate caused by vibration and achieves the matching of vibration information with the printing sequence. Then, the target printing image is located from the image library to be printed based on the time parameters, and the offset of the target printing image is compensated by combining the spatial coordinate parameters, finally obtaining the compensated printing image. This invention specifically corrects the spatial position offset of the pixel slot caused by vibration, so that the ink droplet ejection point is precisely aligned with the pixel slot, effectively solving the printing offset problem caused by low-frequency vibration of the base plane, and significantly improving the landing point accuracy and image quality of inkjet printing.

[0062] Please see Figure 2 Two embodiments of the inkjet printing image offset compensation method in this invention include:

[0063] 201. Install vibration detection sensors on the base plane of the printing platform;

[0064] In this embodiment, refer to Figure 10 and Figure 11 The vibration of the base plane 805 is transmitted to the carrier platform 806, causing a spatial position change in the glass substrate 807 on the carrier platform 806. This manifests as the glass substrate 807 tilting at a certain angle relative to the reference point at the center of the base plane 805. This tilt reduces the physical size of the pixel grooves on the glass substrate 807 relative to the print head reference plane. If not corrected, this will directly affect the accuracy of the ink droplet ejection point. Therefore, the vibration detection sensors 802 must be arranged to completely capture the tilt state of the carrier platform 806. Based on the actual printing scenario and compensation algorithm requirements, this embodiment selects to deploy four vibration detection sensors 802. Vibration detection sensors 802 are respectively installed directly below the four corners of the platform 806, with the center of the base plane 805 set as the reference point, forming a symmetrical acquisition layout. This arrangement allows the four vibration detection sensors 802 to collect the vibration displacement of the four corners of the platform 806 corresponding to the positions on the base plane 805. Subsequently, a complete set of spatial coordinate parameters can be constructed based on the signals from the four vibration detection sensors 802, accurately retrieving the tilt angle and offset of the platform 806 and the glass substrate 807. This provides multi-point data support for subsequent offset compensation, ensuring that the compensation can specifically correct the size changes and positional offsets of the pixel slot caused by tilting.

[0065] 202. The vibration of the base plane is collected by a vibration detection sensor and the vibration is converted into an electrical signal to obtain the base plane vibration signal; the amplitude of the base plane vibration signal is proportional to the physical displacement of the base plane vibration.

[0066] In this embodiment, a passive low-frequency vibration detection sensor is selected. The vibration detection sensor needs to cover the bandwidth of the low-frequency vibration of the base plane, so as to capture the small physical vibration of the base plane in real time and convert the vibration into a weak electrical signal.

[0067] When the physical vibration of the base plane is collected, the intensity of the output base plane vibration signal is on the order of mV. The signal amplitude is proportional to the physical displacement of the base plane vibration. For example, after four vibration detection sensors collect the vibration displacement at their corresponding positions, the output electrical signals are mapped to spatial coordinates [x1, y1, z1], [x2, y2, z2], [x3, y3, z3], and [x4, y4, z4]. Among them, xn and yn are fixed values, corresponding to the physical coordinates of the sensor installation position on the platform, and zn is the spatial displacement corresponding to the collected electrical signal. The four sets of coordinates together constitute the spatial coordinate parameters required for subsequent calculations.

[0068] The spatial position change of the glass substrate is determined by the tilt of the platform. The tilt state of the platform needs to be judged by the vibration displacement of the four corners. Only by ensuring that the electrical signal of each vibration detection sensor corresponds linearly with the displacement can the actual tilt angle of the glass substrate and the offset of the pixel slot be accurately calculated through spatial coordinate parameters. If the signal and the displacement are not proportional, the coordinate parameters will be distorted, and subsequent compensation will not be able to accurately match the actual position of the pixel slot, ultimately causing the ink droplet landing point deviation.

[0069] 203. Transmit the base plane vibration signal to the conditioning device;

[0070] In this embodiment, the intensity of the base plane vibration signal output by the vibration detection sensor is only at the mV level;

[0071] The amplitude of a mV-level signal is too small, far below the standard input range of the printing motherboard's signal processing module. It is easily covered by internal noise of the motherboard, making the signal unable to be effectively identified. Moreover, the interference components contained in the unprocessed signal will cause the printing motherboard to mistakenly identify the interference as vibration displacement. Therefore, if the base plane vibration signal is directly transmitted to the printing motherboard, the printing motherboard cannot directly and accurately extract the spatial coordinate parameters corresponding to the vibration. The base plane vibration signal must first be transmitted to a conditioning device, and the subsequent processing of the conditioning device will convert the weak, interference-containing signal into a stable and pure standard signal.

[0072] Please see Figure 3 The three embodiments of the inkjet printing image offset compensation method in this invention include:

[0073] The conditioning device includes an amplification module, a low-pass filter module, and a high-pass filter module.

[0074] 301. The vibration signal of the base plane is linearly amplified by the amplification module, and its signal amplitude is increased to the preset standard voltage range to form an amplified signal;

[0075] In this embodiment, since the base plane vibration signal is at the mV level, this amplitude is far below the optimal input range of the low-pass and high-pass filter modules. If it directly enters the filter module, the signal is easily covered by internal noise, resulting in the loss of vibration information. Therefore, the amplification module adopts a linear amplification method to boost the mV-level signal amplitude to a preset standard voltage range (such as -10V to +10V, -12V to +12V, etc.). During the amplification process, it ensures that the proportional relationship between the signal amplitude and the physical displacement is not destroyed (e.g., 1μm displacement in the original signal corresponds to 0.2mV signal, and after 1000 times linear amplification, 1μm displacement corresponds to 2V signal), avoiding deviations caused by amplification distortion. Through linear amplification, the problem of weak signals being difficult to process is solved, providing a signal input of sufficient strength for the subsequent filter module, while ensuring the accuracy of vibration displacement and electrical signal.

[0076] 302. Use a low-pass filter module to filter out the preset high-frequency threshold signal from the amplified signal to obtain a low-pass processed signal;

[0077] In this embodiment, the vibration of the base plane is mainly low-frequency vibration (e.g., 0.001Hz to 1000Hz), while the operation of motors and the switching of equipment in the workshop environment will generate high-frequency noise (usually higher than 1000Hz). This high-frequency noise will be superimposed on the amplified signal. If it is not filtered out, it will be misjudged as high-frequency vibration, causing the zn value in the calculated set of [xn, yn, zn] to contain false displacement. This will cause the printing platform to deviate in its tilt correction of the glass substrate (e.g., including the false displacement corresponding to the high-frequency noise in the compensation, resulting in over-correction). Therefore, the low-pass filter module presets a specific high-frequency threshold (e.g., 1000Hz) and uses hardware circuitry to completely filter out high-frequency components in the amplified signal that are higher than this threshold, retaining only low-frequency signals below 1000Hz (i.e., the signals corresponding to the real vibration of the base plane). This ensures that the signal processed by the subsequent high-pass filter module only contains the effective vibration information of the base plane, avoiding high-frequency interference from affecting the compensation accuracy.

[0078] 303. Use a high-pass filter module to filter out the preset low-frequency threshold from the low-pass processed signal to obtain a boosted electrical signal;

[0079] In this embodiment, although the low-pass processed signal has removed high-frequency interference, it may still have low-frequency drift (such as sensor zero drift, baseline offset caused by temperature changes, usually below 10Hz). This type of drift is not generated by the actual vibration of the base plane. If it is retained, it will cause the signal baseline to be unstable and cause systematic deviation when calculating the zn value. Therefore, the high-pass filter module presets a specific low-frequency threshold (such as 10Hz) to filter out the low-frequency drift components below the threshold in the low-pass processed signal, and only retains the vibration signal from 10Hz to 1000Hz. For the base plane low-frequency vibration below 10Hz (such as 0.001Hz to 10Hz), it will be further processed by the frequency domain expansion module to ensure that no effective vibration information is missed. Through high-pass filtering, a boosted electrical signal with a stable baseline and no low-frequency drift is finally obtained. This signal can accurately reflect the actual vibration state of the base plane from 10Hz to 1000Hz, providing a high-quality signal input for subsequent frequency domain expansion compensation and spatial coordinate parameter extraction.

[0080] Please see Figure 4 The four embodiments of the inkjet printing image offset compensation method in this invention include:

[0081] The conditioning device includes a frequency domain detection module and a second-order filtering module;

[0082] In this embodiment, although the boosted electrical signal obtained by amplification and high-pass and low-pass filtering has removed high-frequency interference and low-frequency drift, it may not be able to cover the full-frequency vibration of the actual base plane (especially the ultra-low frequency vibration from 0.001Hz to 10Hz) due to the bandwidth limitation of the vibration detection sensor itself and the threshold setting of the filtering module. If this part of the low-frequency vibration signal is missed, the printing platform will not be able to identify the tilt of the glass substrate caused by the ultra-low frequency vibration, resulting in a compensation blind zone and ultimately causing the ink droplet landing point deviation. Therefore, it is necessary to accurately identify the effective frequency range of the boosted electrical signal through the frequency domain detection module, and then use the second-order filtering module to extend and compensate the uncovered frequency band to ensure that the output extended frequency electrical signal can fully reflect the vibration state of all frequencies of the base plane that need to be compensated, and the signal strength is maintained at the V level.

[0083] 401. Use the frequency domain detection module to determine the effective frequency domain range of the boost signal;

[0084] In this embodiment, the frequency domain detection module determines the actual effective frequency domain boundary by analyzing the frequency components of the boosted electrical signal in real time. For example, after being processed by the high-pass filter module (with a preset low-frequency threshold of 10Hz), the effective frequency domain of the boosted electrical signal may only be 10Hz to 1000Hz, while the base plane actually has ultra-low frequency vibrations of 0.5Hz to 10Hz. Although these vibration signals are collected by the sensor, they are not retained in the boosted electrical signal due to the high-pass filter threshold limitation, or due to the limitation of the sensor's own frequency band, and some ultra-low frequency vibration signals are not effectively converted into electrical signals. The frequency domain detection module needs to accurately capture this "frequency domain gap" and identify the vibration frequency range that the boosted electrical signal does not currently cover, providing a target direction for the subsequent frequency domain expansion of the second-order filter module, avoiding blind expansion that leads to signal distortion, and ensuring that the expanded signal can accurately match the frequency characteristics of the actual vibration of the base plane.

[0085] 402. If the effective frequency domain range does not completely cover the preset base plane vibration compensation frequency, the boosted electrical signal is frequency domain extended through a second-order filtering module to obtain the frequency-extended electrical signal.

[0086] In this embodiment, when the frequency domain detection module detects that the effective frequency domain of the boost signal does not completely cover the preset compensation frequency, the second-order filtering module initiates frequency domain extension processing. The second-order filtering module can use hardware circuits such as Butterworth filters, Chebyshev filters, Bessel filters, or Gaussian filters to adjust the filtering parameters according to the uncovered frequency range. For example, if the 3dB bandwidth of the second-order filter is set to 0.5Hz for the low-frequency gap from 0.5Hz to 10Hz, the effective frequency domain of the boost signal is extended downward from 10Hz to 0.5Hz. If an uncovered range is detected at the high-frequency end, the frequency domain can be extended upward to 1000Hz to achieve full-band coverage.

[0087] Please see Figure 5 The five embodiments of the inkjet printing image offset compensation method in this invention include:

[0088] 501. Control the printing platform to acquire the topology signal from the conditioning device;

[0089] In this embodiment, the printing platform is connected to the conditioning device. Under the coordination of the control device, the platform collects the frequency-modulated electrical signal from the conditioning device at a preset acquisition frequency (adapted to the ink droplet ejection frequency, such as 200Hz). During the acquisition process, the printing platform will simultaneously acquire the frequency-modulated electrical signal corresponding to all vibration detection sensors to avoid mismatch of vibration data from different sensors due to acquisition time difference, and ensure that the overall tilt state of the platform and glass substrate can be judged by comprehensive analysis of multiple signals.

[0090] 502. Map the vibration displacement corresponding to the frequency-modulated electrical signal to the z-axis parameter in spatial coordinates, and map the spatial position of each vibration detection sensor on the base plane to the x-axis and y-axis parameters to form spatial coordinate parameters;

[0091] In this embodiment, since the amplitude of the superposition signal is proportional to the physical displacement of the base plane vibration, the printing platform can use a preset mapping algorithm to map the vibration displacement corresponding to the superposition signal to the z-axis parameter (zn) in spatial coordinates. For example, assuming the amplitude of a certain superposition signal is 3V, the vibration displacement at this position is calculated to be 1.5μm based on the previous linear amplification ratio, i.e., the corresponding z-axis parameter zn = 1.5μm. At the same time, the spatial positions of each vibration detection sensor on the base plane are known fixed values, and the printing platform can directly map these fixed positions to the x-axis parameter (xn) and y-axis parameter (yn) in spatial coordinates. Finally, the printing platform restores the spatial coordinate parameters [xn, yn, zn] collected by each vibration detection sensor based on the superposition signal. The spatial coordinate parameters completely reflect the spatial displacement state of the four corners of the platform, and the printing platform can calculate the overall tilt angle of the platform and the spatial offset of the glass substrate based on these spatial coordinate parameters.

[0092] 503. Record the time information of each acquisition of the topology electrical signal to generate time parameters corresponding to the spatial coordinate parameters;

[0093] In this embodiment, while the printing platform acquires the topology electrical signal and generates spatial coordinate parameters [xn, yn, zn] each time, it records the precise information of the current acquisition time through its built-in clock module. This time information is the time parameter tn corresponding to the spatial coordinate parameters. Since the images in the printing platform's image library are pre-sorted by their spray sequence number and associated with the printing sequence, it is only necessary to establish a mapping relationship between the time parameter tn and the spray sequence number of the image to be printed to determine which image to be printed should match a certain vibration state. The correspondence between the time parameter and the spatial coordinate parameter is the core guarantee for achieving real-time compensation, ensuring that each image to be printed can be corrected based on the actual vibration state at the acquisition time.

[0094] Please see Figure 6 The six embodiments of the inkjet printing image offset compensation method in this invention include:

[0095] 601. Establish a mapping relationship between time parameters and the inkjet serial number of the image to be printed, so that each time parameter is matched with a unique inkjet serial number of the image to be printed;

[0096] In this embodiment, before starting printing, the printing platform will pre-set the jetting sequence of the image to be printed. Each image in the image library to be printed is assigned a unique jetting sequence number, and each jetting sequence number corresponds to a fixed jetting time window. Based on this sequence, the printing platform establishes a mapping rule between time parameters and jetting sequence numbers. The time parameter tn of each acquisition of the topology signal is matched with the jetting time window of the image to be printed. If the time parameter tn falls within the time window corresponding to a certain jetting sequence number, then the time parameter tn matches the jetting sequence number.

[0097] The core logic of this mapping design is that the vibration of the base plane changes in real time. The vibration state at different times can only accurately compensate for the image ejected at that time. If a time parameter tn matches multiple ejection numbers, multiple images will share the same vibration data, which cannot adapt to the actual vibration differences when each image is ejected. If the ejection number does not have a corresponding time parameter tn, the image cannot be compensated based on real-time vibration, which will eventually lead to ink droplet droplet deviation. Therefore, the mapping relationship between the time parameter and the ejection number of the image to be printed is the basis for achieving real-time compensation, ensuring that each image can obtain exclusive vibration data support.

[0098] 602. Using the inkjet serial number of the image to be printed as an index, retrieve the corresponding image to be printed from the preset image library, and determine the retrieved image to be printed as the target image to be printed.

[0099] In this embodiment, all images in the preset image library to be printed are stored with the spray sequence number as the core index, and the index and image data form a corresponding lookup table. When the spray sequence number of the image to be printed is determined to match a certain time parameter tn, the printing platform directly uses the spray sequence number of the image to be printed as the keyword to search in the lookup table of the image library to be printed, quickly retrieves the corresponding image to be printed, and determines it as the target printing image.

[0100] Please see Figure 7 The seven embodiments of the inkjet printing image offset compensation method in this invention include:

[0101] 701. Obtain historical spatial coordinate parameters and generate a coordinate array based on the historical spatial coordinate parameters and the spatial coordinate parameters;

[0102] In this embodiment, while collecting the current spatial coordinate parameters, the printing platform retrieves the recent historical spatial coordinate parameters from the built-in storage module; the historical spatial coordinate parameters are a set generated at a fixed collection frequency within the past few milliseconds; subsequently, the printing platform integrates the historical spatial coordinate parameters and the current spatial coordinate parameters in the order of collection time to generate a coordinate array [X,Y,Z].

[0103] The low-frequency vibration of the base plane is continuous, and the coordinate parameters at a single moment may be affected by instantaneous disturbances (such as sudden micro-impacts), resulting in deviations in the calculated tilt state of the glass substrate. However, the coordinate array formed by integrating historical and real-time data can smooth out the fluctuations caused by instantaneous disturbances, more accurately reflect the actual tilt trend of the platform and the glass substrate, and avoid errors in the compensation direction due to accidental deviations.

[0104] 702. Calculate the Cartesian coordinate parameters from the coordinate array using the orthogonal mapping method;

[0105] In this embodiment, since the vibration of the base plane will cause the platform and glass substrate to tilt relative to the absolute horizontal plane, if the pixel slot position is directly calculated based on the coordinate array of the tilted state, the projection size of the pixel slot on the print head printing reference plane will be compressed or stretched due to the tilt, thus misjudging the ink droplet ejection position.

[0106] The orthogonal mapping method establishes an orthogonal coordinate system (with the reference point at the center of the base plane as the origin, the horizontal direction as the x-axis and y-axis, and the vertical direction as the z-axis). It maps the tilted spatial positions corresponding to each group [xn, yn, zn] in the coordinate array [X, Y, Z] onto the absolute horizontal plane according to orthogonal projection rules. For example, when the glass substrate is tilted along the x-axis, causing a 0.5μm fluctuation in the z-axis collected by one vibration sensor and a 0.3μm fluctuation in the z-axis collected by another vibration sensor, the orthogonal mapping method calculates the difference in displacement between the two z-axis values ​​to deduce the tilt angle of the glass substrate. It then corrects the pixel slot position in the tilted state to its corresponding position on the absolute horizontal plane, ultimately obtaining the Cartesian coordinate parameters xp and yp that reflect the true horizontal projection of the pixel slot. The orthogonal mapping method eliminates the dimensional deviation caused by tilting, ensuring that the calculated Cartesian coordinate parameters xp and yp accurately correspond to the actual position of the pixel slot on the absolute horizontal plane.

[0107] 703. Convert Cartesian coordinate parameters to polar coordinate parameters using coordinate system transformation; the polar coordinate parameters include offset distance and rotation angle;

[0108] In this embodiment, although the Cartesian coordinate parameters xp and yp can reflect the position of the pixel slot on the absolute horizontal plane, the image compensation of inkjet printing needs to clarify the "offset magnitude" and "offset direction", and the polar coordinate parameters can intuitively reflect these two key pieces of information.

[0109] The inkjet printing platform converts Cartesian coordinate parameters xp and yp into polar coordinate parameters (ρ, θ) using coordinate system transformation methods (such as mathematical conversion formulas between polar coordinates and Cartesian coordinates). Here, ρ represents the offset distance of the pixel slot relative to the reference origin (center of the glass substrate), and θ represents the rotation angle of the pixel slot relative to the positive x-axis. The inkjet printing platform can directly perform offset correction on the pixels of the target printed image based on these two parameters.

[0110] 704. Perform offset compensation on the target printed image based on the offset distance and rotation angle to obtain a compensated printed image;

[0111] In this embodiment, the printing platform first determines the pixel distribution of the target printed image. The target image contains multiple pixels, each corresponding to a pixel slot on the glass substrate, and the original coordinates of each pixel in the image have been preset (based on an ideal horizontal state without vibration). Subsequently, based on the polar coordinate parameters obtained in the previous step, the printing platform performs offset correction on all pixels in the target printed image: for each pixel, the offset distance correction amount (ρ) and rotation angle correction amount (θ) corresponding to the pixel are calculated according to its original coordinates and the relative position of the reference origin. Then, the position of the pixel in the image is moved by a distance ρ along the θ direction according to the correction amount. Through pixel-level correction, the pixel distribution of the target printed image is made to perfectly match the actual pixel slot position of the glass substrate caused by vibration.

[0112] After correction, the printing platform encapsulates the corrected image data of all pixels into nozzle data packets according to the internal communication protocol to form a compensated printing image. Then, the printhead ejects ink droplets according to the compensated printing image, so that the ink droplets can fall accurately into the corresponding pixel slots, eliminating the ink droplet landing point deviation caused by the vibration of the base plane, and finally achieving high-precision inkjet printing.

[0113] The inkjet printing image offset compensation method in the embodiments of the present invention has been described above. The inkjet printing image offset compensation system in the embodiments of the present invention will be described below. Please refer to [link / reference]. Figure 8 One embodiment of the inkjet printing image offset compensation system in this invention includes:

[0114] The inkjet printing image offset compensation system includes: a control device 801 and a vibration detection sensor 802, a conditioning device 803 and a printing platform 804 electrically connected to the control device 801; the control device 801 is used to execute the inkjet printing image offset compensation method as described above.

[0115] Figure 9This is a schematic diagram of the structure of an inkjet printing image offset compensation device 900 provided in an embodiment of the present invention. The inkjet printing image offset compensation device 900 can vary considerably due to different configurations or performance. It may include one or more central processing units (CPUs) 910 (e.g., one or more processors) and a memory 920, and one or more storage media 930 (e.g., one or more mass storage devices) storing application programs 933 or data 932. The memory 920 and storage media 930 can be temporary or persistent storage. The program stored in the storage media 930 may include one or more modules (not shown in the diagram), each module including a series of instruction operations on the inkjet printing image offset compensation device 900. Furthermore, the processor 910 may be configured to communicate with the storage media 930 and execute the series of instruction operations in the storage media 930 on the inkjet printing image offset compensation device 900 to implement the steps of the inkjet printing image offset compensation method provided in the above-described method embodiments.

[0116] The inkjet printing image offset compensation device 900 may also include one or more power supplies 940, one or more wired or wireless network interfaces 950, one or more input / output interfaces 960, and / or one or more operating systems 931, such as Windows Server, Mac OS X, Unix, Linux, FreeBSD, etc. Those skilled in the art will understand that... Figure 9 The illustrated structure of the inkjet printing image offset compensation device does not constitute a limitation on the inkjet printing image offset compensation device. It may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0117] The present invention also provides a computer-readable storage medium, which can be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the steps of the inkjet printing image offset compensation method.

[0118] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system, device, or unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0119] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0120] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for compensating image offset in inkjet printing, characterized in that, An inkjet printing image offset compensation system is applied, comprising: a control device and a vibration detection sensor, a conditioning device, and a printing platform electrically connected to the control device; the inkjet printing image offset compensation method includes the following steps: Vibration sensors are used to collect vibration signals from the base plane, and these signals are then transmitted to a conditioning device. The vibration signal of the base plane is amplified and filtered using a conditioning device to obtain a boosted electrical signal; A frequency-domain spread compensation is performed on the boosted electrical signal using a conditioning device to obtain a frequency-spread electrical signal; the frequency-domain spread compensation is performed on the boosted electrical signal using a conditioning device to obtain the frequency-spread electrical signal, including: The conditioning device includes a frequency domain detection module and a second-order filtering module; The effective frequency range of the boost signal is determined using a frequency domain detection module. If the effective frequency domain range does not completely cover the preset base plane vibration compensation frequency, the boosted electrical signal is frequency-domain extended through a second-order filtering module to obtain the frequency-extended electrical signal. The control inkjet printing platform collects the topology electrical signal from the conditioning device and extracts spatial coordinate parameters and time parameters from the topology electrical signal; The target image to be printed is determined from a pre-defined image library based on time parameters; Offset compensation is performed on the target printed image based on spatial coordinate parameters to obtain a compensated printed image.

2. The inkjet printing image offset compensation method according to claim 1, characterized in that, The step of acquiring base plane vibration signals using a vibration detection sensor and transmitting the base plane vibration signals to a conditioning device includes: Vibration detection sensors are placed on the base plane of the printing platform; A vibration detection sensor is used to collect the physical vibration of the base plane and convert the vibration amount into an electrical signal to obtain the base plane vibration signal; the amplitude of the base plane vibration signal is proportional to the physical displacement of the base plane vibration. The vibration signal of the base plane is transmitted to the conditioning device.

3. The inkjet printing image offset compensation method according to claim 1, characterized in that, The process of amplifying and filtering the base plane vibration signal using a conditioning device to obtain a boosted electrical signal includes: The conditioning device includes an amplification module, a low-pass filter module, and a high-pass filter module; The vibration signal of the base plane is linearly amplified by the amplification module, and its signal amplitude is increased to the preset standard voltage range to form an amplified signal. The low-pass filter module is used to filter out the preset high-frequency threshold signal from the amplified signal to obtain the low-pass processed signal; A high-pass filter module is used to filter out the preset low-frequency threshold from the low-pass processed signal to obtain a boosted electrical signal.

4. The inkjet printing image offset compensation method according to claim 1, characterized in that, The control printing platform acquires the frequency-spreading electrical signal from the conditioning device, and extracts spatial coordinate parameters and time parameters from the frequency-spreading electrical signal, including: The control inkjet printing platform acquires topology electrical signals from the conditioning device; The vibration displacement corresponding to the frequency-spreading electrical signal is mapped to the z-axis parameter in spatial coordinates, and the spatial position of each vibration detection sensor on the base plane is mapped to the x-axis and y-axis parameters to form spatial coordinate parameters; Record the time information of each acquisition of the topology electrical signal to generate time parameters corresponding to the spatial coordinate parameters.

5. The inkjet printing image offset compensation method according to claim 1, characterized in that, The step of determining the target image for printing from a preset image library based on time parameters includes: Establish a mapping relationship between time parameters and the inkjet serial number of the image to be printed, so that each time parameter is matched with a unique inkjet serial number of the image to be printed; Using the inkjet serial number of the image to be printed as an index, the corresponding image to be printed is retrieved from the preset image library, and the retrieved image to be printed is determined as the target image to be printed.

6. The inkjet printing image offset compensation method according to claim 1, characterized in that, The offset compensation of the target printed image based on spatial coordinate parameters to obtain a compensated printed image includes: Obtain historical spatial coordinate parameters and generate a coordinate array based on the historical spatial coordinate parameters and the spatial coordinate parameters; The Cartesian coordinate parameters are calculated from the coordinate array using the orthogonal mapping method; The Cartesian coordinate parameters are converted to polar coordinate parameters using a coordinate system transformation method; the polar coordinate parameters include offset distance and rotation angle. Offset compensation is performed on the target printed image based on the offset distance and rotation angle to obtain a compensated printed image.

7. An inkjet printing image offset compensation system, characterized in that, The inkjet printing image offset compensation system includes a control device and a vibration detection sensor, a conditioning device, and a printing platform electrically connected to the control device; the control device is used to execute the inkjet printing image offset compensation method as described in any one of claims 1-6.

8. An inkjet printing image offset compensation device, characterized in that, The inkjet printing image offset compensation device includes: a memory and at least one processor, wherein the memory stores instructions; At least one of the processors invokes the instructions in the memory to cause the inkjet printing image offset compensation device to perform the steps of the inkjet printing image offset compensation method as described in any one of claims 1-6.

9. A computer-readable storage medium storing instructions thereon, characterized in that, When the instructions are executed by the processor, they implement the steps of the inkjet printing image offset compensation method as described in any one of claims 1-6.

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