CN115008900A - Method and system for edge straightness control of flexible display inkjet printing film - Google Patents

Abstract

The invention belongs to the technical field of flexible display, and particularly relates to a method and a system for controlling the edge straightness of a flexible display spray printing film, wherein the method comprises the following steps: adjusting input parameters and controlling the liquid film to test and print within the effective range of each input parameter for printing so that the thickness of the liquid film meets the requirement of the liquid film; collecting a liquid film edge contour picture for calculating a liquid film edge straightness parameter under the current input parameter, if the straightness parameter does not reach the straightness constraint, correcting the input parameter and continuing to control trial printing until the straightness constraint is reached to obtain an optimal input parameter; controlling formal printing by adopting the optimal input parameters to finish the edge straightness control of the spray printing film; wherein, straightness accuracy parameter includes: an amplitude parameter, a maximum width parameter, a pitch characteristic parameter, and a profile length rate. The invention obtains the optimal input parameters which enable the edge straightness of the liquid film to meet the requirements in the ink-jet trial printing stage, and applies the optimal input parameters to formal printing, thereby obtaining the high-quality liquid film.

Description

Method and system for edge straightness control of flexible display inkjet printing film

technical field

The invention belongs to the technical field of flexible display, and more particularly, relates to a method and system for controlling the edge straightness of a flexible display printing film.

Background technique

Inkjet printing technology is a non-contact, low-cost, directly patternable deposition technology that has been widely used in the electronics industry. Because of its advantages of simple process, high resolution, low material loss, and suitability for large-area preparation, inkjet printing technology has shown great potential in the production of OLED display devices, and it will gradually replace vacuum thermal evaporation technology and become the most advanced technology. Promising OLED display manufacturing technology. At present, the preparation of liquid films by inkjet printing technology is mainly used in the field of TFE thin film packaging.

When using inkjet printing to prepare organic encapsulation films, the quality of the organic functional layer film determines the brightness uniformity and lifespan of inkjet-printed OLED devices. However, in the formal printing process, due to the larger size of the OLED panel, it is more difficult to control the straightness of the edge of the liquid film after printing, and the worse the straightness of the edge of the liquid film, the easier it will be in the subsequent cutting process. Cutting to the edge of the film will cause the film to come into direct contact with the air. Moisture and oxygen in the air will react with the OLED through the liquid film, resulting in packaging failure, which reduces the yield of the OLED display and increases the production cost. Therefore, there is an urgent need in the art for a method for further improving the straightness control method of the edge of the liquid film, which can reduce the cost and meet the increasing technological requirements.

SUMMARY OF THE INVENTION

Aiming at the defects and improvement requirements of the prior art, the present invention provides a method and system for controlling the edge straightness of a flexible display inkjet printing film, the purpose of which is to obtain the highest degree of straightness that makes the edge of the liquid film meet the requirements in the inkjet trial printing stage. Optimize the input parameters and apply it to formal printing to obtain high-quality liquid films.

In order to achieve the above purpose, according to one aspect of the present invention, a method for controlling the edge straightness of a flexible display printing film is provided, comprising:

Within the valid range of the input parameters for printing, adjust the input parameters and control the liquid film test printing, so that the thickness of the liquid film meets the requirements of the liquid film; collect the contour picture of the liquid film edge to calculate the straightness parameter of the liquid film edge under the current input parameters , if the straightness parameter does not reach the straightness constraint, correct the input parameters and continue to control the trial printing until the straightness constraint is reached, and the optimal input parameters are obtained;

Use the optimal input parameters to control the formal printing, and complete the edge straightness control of the printing film;

Wherein, the straightness parameters include: amplitude parameter L _a , maximum width parameter L _z , spacing characteristic parameter L _sm , and contour length ratio L _mr(e) ; L _a represents the distance between each point on the liquid film edge contour and the reference line The arithmetic mean of the distance between them; L _z represents the sum of the maximum peak height and the maximum valley depth from the reference line on the edge profile of the liquid film; L _sm represents the width of the contour unit composed of all peaks and adjacent valleys on the edge profile of the liquid film Average value; L _mr(e) represents the ratio of the sum of the lengths of all intersecting line segments to the sampling length of the liquid film edge contour after the parallel line at a distance e from the reference line intersects with the liquid film edge contour.

Further, the effective range is determined in the following manner:

Based on the area to be printed on the liquid film, simulated jet printing is performed, and the straightness of the edge contour of the liquid film is used as a reference index to determine the effective range of each input parameter for printing.

Further, the method of calculating the straightness parameter of the edge of the liquid film under the current input parameters is as follows:

Based on the liquid film edge contour picture, extract the liquid film edge coordinate data (x _i , y _i ), where x _i represents the abscissa of the sampling point, and y _i represents the ordinate of the point corresponding to the contour line;

Based on the liquid film edge data (x _i , y _i ), fit the liquid film edge contour line function L(x), and determine the reference line of the liquid film edge contour line function L(x);

Calculate the straightness parameters of the liquid film edge profile:

L _z =L _p +L _v =max{L(x)-y _D } _p +max{L(x)-y _D } _v ;

Among them, L _t represents the sampling length of the liquid film edge contour; L _p and L _v represent the maximum peak height and the maximum valley depth from the reference line on the liquid film edge contour, respectively, the subscript P represents the peak height, and the subscript V represents the valley depth; y _D represents the reference line of the liquid film edge profile; L _si represents the width of the profile unit, which is the length of the line segment obtained after the combination of a peak and an adjacent valley of the liquid film edge profile intersects the reference line; a line parallel to the reference line It is a straight line with a distance of e from the reference line, l(e) represents the sum of the length _ki of the line segment where the straight line intersects the contour line of the edge of the liquid film, n is the total number of sampling points, and m represents the total number of contour units.

Further, a polynomial is used to fit the liquid film edge contour function L(x).

Further, the straightness constraint is:

Among them, L _a ^* , L _z ^* , L _sm ^* , and L _mr(e) ^* respectively represent the standard requirements of the process for the straightness of the liquid film edge contour in the actual printing process.

Further, when the liquid film thickness does not meet the requirements, the adjustment steps ΔR, Δv and Δd of each input parameter are respectively:

Among them, R ₁ , v ₁ and d ₁ respectively represent the calibration value of the ink droplet radius, the speed calibration value and the ink droplet spacing calibration value, which are used to correct the input parameters R, v, and d.

When the straightness parameters of the edge of the liquid film do not meet the requirements, the adjustment steps ΔR, Δv and Δd of each input parameter are:

ΔR=R _a (L _a -L _a ^* )+R _z (L _z -L _z ^* )+R _sm (L _sm -L _sm ^* )+R _mr(e) (L _mr(e) -L _{mr( e)} ^* );

Δv _{=va (L a -L a * )} ⁺ v _z (L _z -L _z ^* )+v _sm (L _sm -L _sm ^* )+v _mr(e) (L _mr(e) -L _{mr( e)} ^* );

Δd=d _a (L _a -L _a ^* )+d _z (L _z -L _z ^* )+d _sm (L _sm -L _sm ^* )+d _mr(e) (L _mr(e) -L _{mr( e)} ^* );

Among them, L _a ^* , L _z ^* , L _sm ^* , L _mr(e) ^* respectively represent the standard requirements of the process for the straightness of the liquid film edge contour during the actual printing process; R _a , R _z , R _sm , R _{mr ( e)} represents the calibration value of the ink droplet radius; v _a , v _z , v _sm , v _mr(e) represent the speed calibration value; d _a , d _z , d _sm , d _mr(e) represent the calibration value of the ink droplet spacing, using to correct the input parameters R, v, d.

The invention also provides a flexible display jet printing film edge straightness control system, comprising: a vision module and a system control module;

The system control module is used to adjust the input parameters and control the test printing of the liquid film within the effective range of the input parameters for printing, so that the thickness of the liquid film meets the requirements of the liquid film;

The vision module is used for collecting liquid film edge contour pictures;

The system control module is also used to calculate the straightness parameter of the liquid film edge under the current input parameters based on the liquid film edge profile picture, if the straightness parameter does not reach the straightness constraint, correct the input parameter and continue to control the trial printing until it reaches a straight line. degree constraints to obtain optimal input parameters; use the optimal input parameters to control formal printing;

Wherein, the straightness parameters include: amplitude parameter L _a , maximum width parameter L _z , spacing characteristic parameter L _sm , and contour length ratio L _mr(e) ; L _a represents the distance between each point on the liquid film edge contour and the reference line The arithmetic mean of the distance between them; L _z represents the sum of the maximum peak height and the maximum valley depth from the reference line on the edge profile of the liquid film; L _sm represents the width of the contour unit composed of all peaks and adjacent valleys on the edge profile of the liquid film Average value; L _mr(e) represents the ratio of the sum of the lengths of all intersecting line segments to the sampling length of the liquid film edge contour after the parallel line at a distance e from the reference line intersects with the liquid film edge contour.

Further, the system control module uses a white light interferometer to measure the thickness of the liquid film.

Further, the vision module uses a scanning camera to scan the contour picture of the edge of the liquid film.

The present invention also provides a computer-readable storage medium, the computer-readable storage medium includes a stored computer program, wherein when the computer program is run by a processor, the device where the storage medium is located is controlled to execute the above-mentioned one A flexible display printing film edge straightness control method.

In general, through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:

(1) The present invention analyzes the situation of liquid film prepared by inkjet printing technology, defines the straightness parameters of the liquid film edge in a targeted manner, and determines the straightness of the prepared liquid film edge according to the process requirements. The optimal input parameters that make the straightness of the edge of the liquid film meet the requirements are obtained and applied to the formal printing, so as to obtain a high-quality liquid film.

(2) The present invention further relies on the liquid film edge predictor (simulation prediction) to obtain the effective range of each input parameter at the beginning of the trial printing stage, thereby reducing the loss of human, financial and material resources.

(3) The present invention further combines the scanning camera to extract the liquid film edge contour information and calculate the liquid film edge straightness parameter after the printing is completed, so as to realize the quantitative determination of the liquid film edge straightness.

(4) The present invention improves the efficiency of obtaining optimal input parameters by correcting the input parameters of the system according to the situation that the thickness of the liquid film and the straightness of the edge of the liquid film do not meet the standard requirements after the printing is completed.

Description of drawings

1 is a schematic diagram of the overall structure of a system for controlling the edge straightness of a flexible display jet printing film provided by an embodiment of the present invention;

2 is a block diagram of a method for controlling the edge straightness of a flexible display jet printing film provided by an embodiment of the present invention;

3 is a process flow diagram of a method for controlling the edge straightness of a flexible display jet printing film provided by an embodiment of the present invention;

4 is a system flow chart of a method for controlling the edge straightness of a flexible display inkjet printing film provided by an embodiment of the present invention;

5 is a schematic diagram of a liquid film edge reference line in a method for controlling the edge straightness of a flexible display printing film provided by an embodiment of the present invention;

6 is a schematic diagram of a liquid film edge straightness parameter in a process flow diagram of a method for controlling edge straightness of a flexible display inkjet printing film provided by an embodiment of the present invention.

Throughout the drawings, the same reference numbers are used to refer to the same elements or structures, wherein:

1 is the inkjet printing module, 2 is the motion module, 21 is the inkjet printing positioning system, 22 is the moving substrate, 31 is the observation camera, 32 is the first light source, 33 is the positioning camera, 34 is the second light source, and 35 is the scanning Camera, 4 is a system control module, 41 is a main controller, 42 is a liquid film edge straightness calculator, 43 is a liquid film edge straightness predictor, 44 is a white light interferometer, and 45 is a liquid film edge straightness controller.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Example 1

A method for controlling the edge straightness of a flexible display jet printing film, comprising:

Within the valid range of the input parameters for printing, adjust the input parameters and control the liquid film test printing, so that the thickness of the liquid film meets the requirements of the liquid film; collect the contour picture of the liquid film edge to calculate the straightness parameter of the liquid film edge under the current input parameters , if the straightness parameter does not reach the straightness constraint, correct the input parameters and continue to control the trial printing until the straightness constraint is reached, and the optimal input parameters are obtained;

The optimal input parameters are used to control the formal printing, and the edge straightness control of the printing film is completed;

Wherein, the straightness parameters include: amplitude parameter L _a , maximum width parameter L _z , spacing characteristic parameter L _sm , and contour length ratio L _mr(e) ; L _a represents the distance between each point on the liquid film edge contour and the reference line The arithmetic mean of the distance between them; L _z represents the sum of the maximum peak height and the maximum valley depth from the reference line on the edge profile of the liquid film; L _sm represents the width of the contour unit composed of all peaks and adjacent valleys on the edge profile of the liquid film Average value; L _mr(e) represents the ratio of the sum of the lengths of all intersecting line segments to the sampling length of the liquid film edge contour after the parallel line at a distance e from the reference line intersects with the liquid film edge contour.

In order to better illustrate the present invention, a specific control system is now given to illustrate the control method of this embodiment.

Fig. 1 is the edge straightness control system for flexible display printing film constructed by the present invention. As shown in FIG. 1 , the system includes an inkjet printing module, a motion module, a vision module and a system control module, which will be explained in detail below.

The inkjet printing module 1 is used to generate ink droplets of corresponding volume and impact velocity to deposit on the moving substrate 22 as required, and flash-jet multiple ink droplets to deposit on the substrate printing area to form a liquid film according to the printing area range on the substrate 22 .

The motion module 2 includes an inkjet printing positioning system 21 composed of an inkjet printing module 1 , a positioning camera 33 , a second light source 34 , and a moving substrate 22 . Among them, the nozzle printing positioning system 21 composed of the nozzle module 1, the positioning camera 33 and the light source 34 can be used by the main controller 41 to use the positioning camera 33 to move to the corresponding position for printing operations after determining the printing position, and the moving substrate 22 can be used by the main controller. 41 Transport the printed liquid film to the edge straightness observation area of the liquid film for observation.

As one of the key improvements of the present invention, the vision module 3 includes an observation camera 31, a first light source 32, a positioning camera 33, a second light source 34, and a scanning camera 35, wherein the observation camera 31 and the first light source 32 are located in the observation camera 31 and the first light source 32 to observe the ink droplets. The area is used to observe the ink droplets before the inkjet printing liquid film operation, obtain the flying image of the ink droplets when they are ejected, and feed back the image information to the main controller 41 in real time, and observe the flying state, speed and volume of the ink droplets and analyze them. Determine the stable state when the ink droplets are ejected; the positioning camera 33 and the second light source 34 are located in the inkjet printing positioning system 21, the main controller 41 uses the positioning camera 33 to position the printing position of the nozzle module 1; the moving substrate 22 moves to the liquid film When the position of the edge is observed, the scanning camera 35 will scan and photograph the edge of the liquid film and feed back the obtained straightness information of the edge of the liquid film to the straightness calculator 42 of the edge of the liquid film.

In addition, as another key improvement of the present invention, the system control module 4 includes a main controller 41, a liquid film edge straightness calculator 42, a liquid film edge straightness predictor 43, a white light interferometer 44 and a liquid film edge straightness The controller 45, wherein the main controller 41 is used to control the size and impact speed of the ink droplets in the inkjet printing module 1 when they are ejected; used to select the position of the inkjet printing positioning system 21 in the motion module 2 and control the movement of the substrate 22. It is used to obtain various image information in the vision module and make corresponding judgments; in addition, the system control module 4 includes a liquid film edge controller 41, and the liquid film edge controller 41 is based on the liquid film edge obtained by the scanning camera 35. The image extracts the relevant data of the liquid film edge and performs calculation, and feeds the obtained results to the main controller 41; the liquid film edge straightness predictor 43 predicts the straightness of the liquid film edge, and obtains the current situation that can make the liquid film edge straightness meet the requirements. The effective range of each input parameter is fed back to the controller 41; the white light interferometer 44 feeds back the information of the overall thickness of the liquid film to the main controller 41; the liquid film edge straightness controller 45 determines the liquid film thickness and the liquid film When the edge straightness does not meet the standard requirements, correct the value of each input parameter.

FIG. 2 is a control block diagram of the edge straightness control system and method for preparing a film prepared by spray printing of a flexible display functional layer provided by the present invention, which will be further explained in detail below.

The system acts on the trial printing stage before the actual printing work starts. First, according to the area S of the liquid film printing area, the liquid film edge straightness predictor 43 predicts the contour of the liquid film edge and obtains various parameters such as the ink droplet size R, the impact speed v, the effective range of the ink droplet spacing d, to avoid the loss of human, financial and material resources; then select each input parameter value within the effective range of each parameter to print; Obtain the overall thickness of the liquid film for analysis. If the film thickness does not meet the requirements, use the liquid film edge straightness controller 45 to correct each input parameter value and print again until the film thickness meets the requirements; on the premise that the overall thickness of the liquid film meets the requirements, The edge straightness is obtained through the scanning camera 35 and the liquid film edge straightness calculator 42. When the liquid film edge straightness does not meet the requirements, the liquid film edge straightness controller 45 is used to correct each input parameter and print again until After obtaining the high-quality liquid film edge contour, record the value of each input parameter and apply it to the actual printing process.

According to a preferred embodiment of the present invention, the system is used in the trial printing stage before the actual printing. According to the printing area range, set the size radius R, speed v and spacing d of ink droplets ejected during inkjet printing. To extract and calculate, first extract the overall thickness information of the liquid film according to the white light interferometer. Let the liquid film thickness of each sampling point be hi , the thickness of the thinnest part of the liquid film to be _{h min ,} and the standard parameter of the liquid film thickness to be δ. When the liquid film thickness satisfies the following formula, it can be considered that the liquid film edge thickness satisfies the standard Require:

In this way, the accumulation of the liquid film edge caused by the shrinkage of the liquid film is prevented. On the premise that the thickness at the edge of the liquid film meets the standard requirements, continue to calculate the straightness of the edge of the liquid film. When the straightness of the edge of the liquid film does not meet the standard, continue to modify the input parameters until the straightness of the edge of the liquid film reaches the standard. The parameter range of is applied to formal printing.

According to a preferred embodiment of the present invention, for the liquid film edge straightness calculator, after acquiring the liquid film edge data (x _i , y _i ), the contour line of the liquid film edge is obtained by fitting according to the following formula:

Let the fitted liquid film edge contour curve be L(x), namely:

L(x)=a ₀ +a ₁ x+a ₂ x ² +...+a _n x ⁿ ;

Among them, a ₀ , a ₁ ,…,an are curve fitting parameters, and the _sum of squares of errors is:

Among them, m≤n.

通过计算得到

使得误差平方和最小，即：According to the system of normal equations

obtained by calculation

Minimize the sum of squared errors, that is:

At this point, the liquid film edge profile curve L(x) can be obtained.

According to a preferred embodiment of the present invention, for the liquid film edge straightness calculator, after obtaining the liquid film edge contour curve, the following steps are performed to calculate and determine the liquid film edge contour straightness:

(1) Determine the baseline contour of the liquid film edge, as shown in Figure 5: The sum of the squares of the distances from each point on the edge of the liquid film to the baseline is the smallest, and the baseline can be obtained according to the following formula:

Among them, L _t represents the sampling length of the liquid film edge contour line; y _D represents the liquid film edge contour reference line.

(2) Calculate the straightness parameters of the liquid film edge profile, as shown in Figure 6: the amplitude parameter _{La, the maximum width parameter L z ,} the spacing characteristic parameter L _sm , and the profile length ratio L _mr(e) . The amplitude parameter L _a represents the arithmetic mean of the absolute value of the distance between each point on the liquid film edge profile and the reference line, as shown in (a) in Figure 6; L _z represents the maximum peak distance from the reference line on the liquid film edge profile The sum of the height and the maximum valley depth, as shown in (b) in Figure 6; L _si represents the width of the contour unit, which is the sum of the line segment obtained after the combination of a peak and an adjacent valley of the liquid film edge contour intersects the reference line. Length, L _sm represents the average width of the contour unit composed of all peaks and adjacent valleys on the edge of the liquid film, as shown in (c) in Figure 6; the contour length ratio L _{mr (e)} represents the distance from the reference line is the ratio of the sum of the lengths of all intersecting line segments after the parallel line of e intersects with the liquid film edge contour to the sampling length of the liquid film edge contour, as shown in (d) in Figure 6. L _a ^* , L _z ^* , L _sm ^* , L _mr(e) ^* are respectively calculated according to the following formulas:

L _z =L _p +L _v =max{L(x)-y _D } _p +max{L(x)-y _D } _v

Among them, L _t represents the sampling length of the liquid film edge contour; L _p and L _v represent the maximum peak height and the maximum valley depth from the reference line on the liquid film edge contour, respectively, the subscript P represents the peak height, and the subscript V represents the valley depth; y _D represents the reference line of the liquid film edge profile; L _si represents the width of the profile unit, which is the length of the line segment obtained after the combination of a peak and an adjacent valley of the liquid film edge profile intersects the reference line; a line parallel to the reference line It is a straight line with a distance of e from the reference line, l(e) represents the sum of the length _ki of the line segment where the straight line intersects the contour line of the edge of the liquid film, n is the total number of sampling points, and m represents the total number of contour units.

(3) Determine the straightness parameters of the edge of the liquid film according to the following requirements:

Among them, L _a ^* , L _z ^* , L _sm ^* , and L _mr(e) ^* respectively represent the standard requirements of the process for the straightness of the liquid film edge contour in the actual printing process.

When L _a is smaller, L _z is smaller, L _si is smaller, and L _mr(e) is larger, the straightness of the edge of the liquid film is more satisfactory. When the four edge straightness parameters meet the above requirements, it can be considered that the parameters input by the system at this time can be used in formal printing.

FIG. 3 and FIG. 4 are the process flow chart and the system flow chart of the edge straightness control system and method for preparing a film prepared by jet printing of a flexible display functional layer provided by the present invention. Correspondingly, the method includes the following steps.

First, in the prediction stage, the liquid film edge straightness predictor is used to predict the liquid film edge contour straightness obtained under the input parameters at this time. When the liquid film edge straightness parameters do not meet the standard requirements, modify the input parameters until the liquid film edge The film edge straightness parameters all meet the standard requirements, and the input parameter values at this time are input into the system control module;

Next, in the initialization stage, the entire system is initialized, and the parameter values obtained by the liquid film edge predictor are input into it;

Next, in the ink drop observation and liquid film printing stages, at the initial moment, the ink droplets with a certain volume and impact speed are printed at the ink drop observation position by the nozzle printing module, and the visual module is used to observe them. When the state of droplet ejection is unstable, adjust the parameters such as air pressure and temperature in the ink circuit system in the inkjet module until the state of ink droplet ejection is stable, use the motion module to move the printhead printing module to the liquid film printing position , according to the range of the printing area, flash-jet multiple ink droplets are deposited on the printing area of the substrate to form a liquid film;

Next, in the observation stage of the straightness of the liquid film edge, first use the motion module to move the liquid film to the liquid film edge observation position, use the system control module to observe the liquid film edge morphology, and measure the overall thickness of the liquid film. When the overall thickness of the liquid film does not meet the requirements, use the straightness control of the liquid film edge to correct the input parameters and repeat the above steps until the overall thickness of the liquid film edge meets the requirements, so as to prevent excessive accumulation of the liquid film edge caused by edge shrinkage; When the overall thickness of the edge of the liquid film meets the requirements, the vision module is used to observe the contour of the edge of the liquid film and feed it back to the system control module to calculate the straightness parameter of the edge of the liquid film. When required, use the liquid film edge straightness control to correct the input parameters and repeat the above steps until the liquid film edge straightness parameters meet the requirements.

Finally, when the straightness parameters of the edge of the liquid film meet the requirements, the input parameter values at this time are recorded and applied to the actual printing operation.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (10)

1. a flexible display printing film edge straightness control method, is characterized in that, comprises: Within the valid range of the input parameters for printing, adjust the input parameters and control the liquid film test printing, so that the thickness of the liquid film meets the requirements of the liquid film; collect the contour picture of the liquid film edge to calculate the straightness parameter of the liquid film edge under the current input parameters , if the straightness parameter does not reach the straightness constraint, correct the input parameters and continue to control the trial printing until the straightness constraint is reached, and the optimal input parameters are obtained; Use the optimal input parameters to control the formal printing, and complete the edge straightness control of the printing film; Wherein, the straightness parameters include: amplitude parameter L _a , maximum width parameter L _z , spacing characteristic parameter L _sm , and contour length ratio L _mr(e) ; L _a represents the distance between each point on the liquid film edge contour and the reference line The arithmetic mean of the distance between them; L _z represents the sum of the maximum peak height and the maximum valley depth from the reference line on the edge profile of the liquid film; L _sm represents the width of the contour unit composed of all peaks and adjacent valleys on the edge profile of the liquid film Average value; L _mr(e) represents the ratio of the sum of the lengths of all intersecting line segments to the sampling length of the liquid film edge contour after the parallel line at a distance e from the reference line intersects with the liquid film edge contour. 2. The method for controlling the edge straightness of a flexible display jet printing film according to claim 1, wherein the effective range is determined by the following methods: Based on the area to be printed on the liquid film, simulated jet printing is performed, and the straightness of the edge contour of the liquid film is used as a reference index to determine the effective range of each input parameter for printing. 3. The method for controlling the edge straightness of a flexible display jet printing film according to claim 1, wherein the method for calculating the edge straightness parameter of the liquid film under the current input parameters is: Based on the liquid film edge contour picture, extract the liquid film edge coordinate data (x _i , y _i ), where x _i represents the abscissa of the sampling point, and y _i represents the ordinate of the point corresponding to the contour line; Based on the liquid film edge coordinate data (x _i , y _i ), fit the liquid film edge contour line function L(x), and determine the reference line of the liquid film edge contour line function L(x); Calculate the straightness parameters of the liquid film edge profile:

L _z =L _p +L _v =max{L(x)-y _D } _p +max{L(x)-y _D } _v ;

Among them, L _t represents the sampling length of the liquid film edge contour; L _p and L _v represent the maximum peak height and the maximum valley depth from the reference line on the liquid film edge contour, respectively, the subscript P represents the peak height, and the subscript V represents the valley depth; y _D represents the reference line of the liquid film edge profile; L _si represents the width of the profile unit, which is the length of the line segment obtained after the combination of a peak and an adjacent valley of the liquid film edge profile intersects the reference line; a line parallel to the reference line It is a straight line with a distance of e from the reference line, l(e) represents the sum of the length _ki of the line segment where the straight line intersects the contour line of the edge of the liquid film, n is the total number of sampling points, and m represents the total number of contour units. 4 . The method for controlling the edge straightness of a flexible display jet printing film according to claim 3 , wherein a polynomial is used to fit the liquid film edge contour function L(x). 5 . 5. The method for controlling the edge straightness of a flexible display printing film according to claim 1, wherein the straightness constraint is:

Among them, L _a ^* , L _z ^* , L _sm ^* , and L _mr(e) ^* respectively represent the standard requirements of the process for the straightness of the liquid film edge contour in the actual printing process. 6. The method for controlling the edge straightness of a flexible display printing film according to claim 5, wherein when the thickness of the liquid film does not meet the requirements, the adjustment step lengths ΔR, Δv and Δd of each input parameter are respectively:

Among them, R ₁ , v ₁ and d ₁ respectively represent the calibration value of the ink droplet radius, the speed calibration value and the ink droplet spacing calibration value, which are used to correct the input parameters R, v, and d. When the straightness parameters of the edge of the liquid film do not meet the requirements, the adjustment steps ΔR, Δv and Δd of each input parameter are: ΔR=R _a (L _a -L _a ^* )+R _z (L _z -L _z ^* )+R _sm (L _sm -L _sm ^* )+R _mr(e) (L _mr(e) -L _{mr( e)} ^* ); Δv _{=va (L a -L a * )} ⁺ v _z (L _z -L _z ^* )+v _sm (L _sm -L _sm ^* )+v _mr(e) (L _mr(e) -L _{mr( e)} ^* ); Δd=d _a (L _a -L _a ^* )+d _z (L _z -L _z ^* )+d _sm (L _sm -L _sm ^* )+d _mr(e) (L _mr(e) -L _{mr( e)} ^* ); Among them, L _a ^* , L _z ^* , L _sm ^* , L _mr(e) ^* respectively represent the standard requirements of the process for the straightness of the liquid film edge contour during the actual printing process; R _a , R _z , R _sm , R _{mr ( e)} represents the calibration value of the ink droplet radius; v _a , v _z , v _sm , v _mr(e) represent the speed calibration value; d _a , d _z , d _sm , d _mr(e) represent the calibration value of the ink droplet spacing, using to correct the input parameters R, v, d. 7. A flexible display printing film edge straightness control system, characterized in that, comprising: a vision module and a system control module; The system control module is used to adjust the input parameters and control the test printing of the liquid film within the effective range of the input parameters for printing, so that the thickness of the liquid film meets the requirements of the liquid film; The vision module is used for collecting liquid film edge contour pictures; The system control module is also used to calculate the straightness parameter of the liquid film edge under the current input parameters based on the liquid film edge profile picture, if the straightness parameter does not reach the straightness constraint, correct the input parameter and continue to control the trial printing until it reaches a straight line. degree constraints to obtain optimal input parameters; use the optimal input parameters to control formal printing; Wherein, the straightness parameters include: amplitude parameter L _a , maximum width parameter L _z , spacing characteristic parameter L _sm , and contour length ratio L _mr(e) ; L _a represents the distance between each point on the liquid film edge contour and the reference line The arithmetic mean of the distance between them; L _z represents the sum of the maximum peak height and the maximum valley depth from the reference line on the edge profile of the liquid film; L _sm represents the width of the contour unit composed of all peaks and adjacent valleys on the edge profile of the liquid film Average value; L _mr(e) represents the ratio of the sum of the lengths of all intersecting line segments to the sampling length of the liquid film edge contour after the parallel line at a distance e from the reference line intersects with the liquid film edge contour. 8 . The method for controlling the edge straightness of a flexible display printing film according to claim 1 , wherein the system control module uses a white light interferometer to measure the thickness of the liquid film. 9 . 9 . The method for controlling the edge straightness of a flexible display inkjet printing film according to claim 1 , wherein the vision module uses a scanning camera to scan the edge contour picture of the liquid film. 10 . 10. A computer-readable storage medium, characterized in that the computer-readable storage medium comprises a stored computer program, wherein, when the computer program is run by a processor, the device where the storage medium is located is controlled to execute as claimed in the claims A method for controlling the edge straightness of a flexible display jet printing film according to any one of 1 to 6.

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