A method for improving laser exposure accuracy

Abstract

The present application embodiment discloses a method for improving laser exposure accuracy, which is applied to the field of laser direct writing technology, including: Step 1: obtaining M rows of image strips to be exposed corresponding to any laser of the laser direct writing device, and each row of image strips is divided into N image segments, totaling M*N compensation values; Step 2: The control module of the laser direct writing device controls the laser to emit light based on the M*N compensation values, exposing the M rows of image strips row by row in order from first to last, so that the M rows of image strips are accurately exposed. This method improves image exposure accuracy by first dividing each row of the M rows of image strips exposed by each laser into N segments, obtaining M*N image segments, and then accurately exposing each image segment based on the M*N compensation values.

Description

Technical Field

[0001] The invention belongs to the technical field of laser direct writing, and in particular relates to a method for improving laser exposure accuracy. Background Art

[0002] refer to Figure 1 In the prior art, a plurality of lasers are mounted in a row on the vertical beam 104 of the laser direct writing device 100 (four lasers 105-1 to 105-4 are shown in the drawing as an example in this application). The upper end of the vertical beam 104 is located on the upper horizontal guide rail 101, the lower end is located on the lower horizontal guide rail 102, and the middle part is located on the upper end of the conveyor belt 106. One end of the conveyor belt 106 is sleeved on the motor 108, and the other end is sleeved on the driven wheel 107. The output shaft sleeve of the motor 108 is provided with a driving wheel 115. Under the control of the control module 109, the motor 108 drives the driving wheel 115 to rotate. The driving wheel 115 drives the conveyor belt 106 to reciprocate horizontally. The conveyor belt 106 drives the vertical beam 104 to reciprocate left and right on the upper horizontal guide rail 101 and the lower horizontal guide rail 102. The plurality of lasers emit light during the horizontal movement, exposing the screen (not shown) set perpendicular to the laser light emission direction, and obtaining the following Figure 2 The exposure image 01 shown consists of several rows of image strips.

[0003] refer to Figure 2 Exemplarily, each of the four lasers 105-1 to 105-4 exposes three image strips (in this application, each laser exposes M image strips, where M is exemplarily 3). These 12 image strips constitute the exposed image 01. The 12 image strips are of equal length and arranged in a column in the vertical direction. The starting position of each image strip is the same in the horizontal direction, and the distance between each adjacent image strip is h. Theoretically, when each row of image strips exposed by any laser is divided into N segments, each of which is L in length, the exposure points formed by the laser after exposing the two end points of each image segment are evenly distributed on the row of image strips. For example, the first row of image strips exposed by laser 105-1 is divided into 5 segments (N is 5 for example). When laser 105-1 exposes the first and last end points of each of the 5 image segments of the first row of image strips from right to left, the 6 exposure points A11 to A16 formed are evenly distributed on the first row of image strips. That is, theoretically, the positions of the first and last exposure points of each image segment exposed by laser 105-1 completely coincide with the preset positions. After exposing the first row of image strips, laser 105-1 Figure 1 Under the control of the control module 109, the rising distance h, when the second row of image strips is exposed from left to right, the exposure points formed after the first and last endpoints of each of the five exposed image segments are completely consistent with the preset positions.

[0004] However, the actual situation is that Figure 1 and Figure 4 Based on the mechanical errors and signal transmission errors caused by the motor 108, the control module 109, the driving wheel 115, and the conveyor belt 106 of the laser direct writing device 100, the actual positions of the first and last exposure points of each image segment of each line of the laser exposed image strip are inconsistent with the preset positions. For example, Figure 4 When the laser 104-1 exposes the first and last two exposure points of each of the five image segments of the first row of the image strip, the five exposure points B12 to B16 actually generated do not overlap with the five preset exposure points A12 to A16 (in this application, the preset position and the actual exposure position of the initial exposure point of the first image segment of any row of the image strip exposed by the laser are set to be the same. For example, the preset position A11 of the first exposure point of the first image segment of the first row of the image strip exposed by the laser 104 is the same as the actual exposure position B12 to B16). 11 This can cause the laser exposure accuracy to decrease. This situation also occurs for image strips of a corresponding number of lines exposed by other lasers. Therefore, if the laser exposure stroke is not adjusted, the image exposure accuracy will be greatly reduced. Summary of the Invention

[0005] The present invention provides a method for improving laser exposure accuracy, which aims to solve the problem of low accuracy of laser exposure images in laser direct writing equipment.

[0006] The scheme of the present invention is as follows:

[0007] A method for improving laser exposure accuracy, used in a laser direct writing device, comprising:

[0008] Step 1: Obtain M rows of image strips to be exposed corresponding to any laser of the laser direct writing device, and each row of image strips is equally divided into N image segments, totaling M*N compensation values;

[0009] Step 2: The control module of the laser direct writing device controls the laser to emit light according to the M*N compensation values, exposing the M lines of image strips row by row in a sequence from the beginning to the end, so that the M lines of image strips are accurately exposed;

[0010] The M rows of image strips in step 1 are of equal length and are vertically distributed in a column; all lasers of the laser direct writing device are in the same vertical position and move, light up and turn off synchronously.

[0011] In some embodiments, step 2 specifically includes:

[0012] Step 21: Select any one of the lasers as the laser at the bottom and define it as the first laser. The control module controls the first laser to sequentially expose N image segments of the first row of image strips at the bottom from right to left in combination with N compensation values.

[0013] Step 22: The control module moves the first laser upward by h based on the actual stopping position of the first laser after exposing the first row of image strips. The control module sequentially exposes N image segments of the second row of image strips from left to right, combining the N compensation values ​​of the second row of image strips.

[0014] Step 23: When the first laser exposes any image strip from the third row to the Mth row, the control module uses the actual stopping position of the first laser after exposing the previous image strip of the arbitrary row as a reference, moves the first laser upward by h, and sequentially exposes N image segments of the arbitrary row of image strips in combination with the N compensation values ​​corresponding to the arbitrary row of image strips by the first laser.

[0015] When the first laser exposes each image segment, the initial exposure position of the first laser needs to be set to coincide with the starting point of each image segment; h is the vertical distance between two adjacent rows of image strips.

[0016] In some embodiments, when the first laser exposes the second row of image strips to the Mth row of image strips, the laser does not emit light within the horizontal displacement from the actual stop position to the first pixel point of the first image segment of the row of image strips.

[0017] In some embodiments, in step 1, the N compensation values ​​in any row of the image strip are calculated by the following method:

[0018] Step 11, defining the length L of each image segment of any P-th image strip in the M image strips to be equal to the theoretical exposure length of the laser within each time interval T;

[0019] Step 12: obtaining the actual displacement Lpx of the laser when sequentially exposing any X-th image segment of N image segments of any P-th row of image strips, and obtaining a total of N actual displacements Lpx;

[0020] Step 13: Subtract the N actual displacements Lpx from the length L of the corresponding image segment to obtain N difference values ​​d PX ,d PX =Lpx-L, N difference values ​​d PX That is, the N compensation values ​​of any P-th row of image strips;

[0021] Wherein, X is any natural number from 1 to N, and P is any natural number from 1 to M.

[0022] In some embodiments, if d PX If it is negative, it means that when the laser is exposing any image segment of any P-th row image strip, the laser is still a distance d away from the end point of the image segment. PX When the exposure of any image segment is completed, the control module needs to control the laser to expose the remaining length d PX That part of the image continues to be exposed; if d PX If it is positive, it means that the laser continues to move forward a distance d after exceeding the end point of any image segment. PX When it is mistakenly considered to have reached the end of any image segment, the control module needs to control the laser to advance by a distance d PX The exposure ends at this time and switches to the exposure of the next image segment.

[0023] In some embodiments, the direction from the starting point to the end point of any image segment of any row of image strips is the movement direction of the laser exposing the row of image strips.

[0024] In some embodiments, L is 100 mm, -50 μm ≤ d PX ≤50μm.

[0025] The beneficial technical effects of the present invention are as follows: each row of the M rows of image strips exposed by each laser is divided into N image segments, obtaining M*N image segments; and the M*N image segments are accurately exposed based on the M*N compensation values ​​provided corresponding to the M*N image segments. This solves the problem of inconsistency between the actual moving path of the laser and the position corresponding to the image strip when the laser exposes the image strip due to mechanical reasons and signal transmission reasons of the laser direct writing device, thereby improving the image exposure accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a simplified structural diagram of the laser direct writing device 100;

[0027] Figure 2 Schematic diagram of the laser direct writing device 100, wherein the four lasers each expose three rows of image strips, each row is divided into five image segments, and each image segment is of length L;

[0028] Figure 3 for Figure 2 Schematic diagram showing three rows of image strips exposed by the first laser 105-1 at the bottom, each row being divided into five image segments, each image segment being of length L;

[0029] Figure 4A comparison diagram of the actual walking path and the preset walking route when the first laser 105-1 exposes 15 image segments according to 15 compensation values;

[0030] Figure 5 1 is a step diagram of the method of this embodiment. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention. The terms "first", "second", and "third" are only used to describe the difference and should not be understood as indicating or implying relative importance. In addition, unless otherwise expressly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate object, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0033] refer to Figure 5 The present invention discloses a method for improving laser exposure accuracy, which is applied to a laser direct writing device, including:

[0034] Step 1: Obtain M rows of image strips to be exposed corresponding to any laser of the laser direct writing device, and each row of image strips is equally divided into N image segments, totaling M*N compensation values;

[0035] Step 2: The control module of the laser direct writing device controls the laser to emit light according to the M*N compensation values, exposing the M lines of image strips row by row in a sequence from the beginning to the end, so that the M lines of image strips are accurately exposed;

[0036] The M rows of image strips in step 1 are of equal length and are vertically distributed in a column; all lasers of the laser direct writing device are in the same vertical position and move, light up and turn off synchronously.

[0037] refer to Figure 1 and Figure 2 In this application, the number of lasers is exemplified as four: 105-1 through 105-4. The centers of these four lasers are all located on the vertical centerline of vertical beam 104. Furthermore, vertical beam 104 remains vertical during its horizontal reciprocating motion. Therefore, the horizontal and vertical motions of these four lasers are always synchronized. Figure 2 and Figure 3 In the example, the number of image strips exposed by each laser is M, exemplarily 3. Each image strip is exemplarily divided into N image segments, N is exemplarily 5, and each image segment is L mm long. Therefore, each laser needs to obtain M*N compensation values, that is, exemplarily a total of 3*5=15 compensation values, in order to accurately expose the corresponding 3 image strips. The 15 compensation values ​​corresponding to the 15 image segments exposed by each laser are determined before exposure and are input into the storage device of the laser direct writing device for storage. Figure 1 The control module 109 of the laser direct writing device controls the laser to perform segmented and precise exposure on 15 image segments of 3-line image strips in sequence according to 15 compensation values, thereby improving the exposure accuracy of the image.

[0038] Refer to Table 1, which is a list of 15 compensation values ​​corresponding to 15 image segments of 3 lines of image strips corresponding to the exposure of laser 105-1. Among them, the 5 compensation values ​​from right to left in the bottom row of Table 1 are: -20μm, -25μm, +15μm, +35μm, +42μm, which correspond to Figure 4 d11-d15; the 5 compensation values ​​from left to right in the middle row of Table 1 are: -18μm, -24μm, +40μm, +48μm, -41μm, corresponding to Figure 4 The top row of Table 1 corresponds to the 5 compensation values ​​from right to left: -27μm, +29μm, 0μm, -41μm, -32μm Figure 4 It should be noted that the specific values ​​of the 15 compensation values ​​listed in the table are only exemplary. The meaning of the positive and negative representations of the compensation values ​​will be described later.

[0039] Table 1:

[0040] -27μm +29μm 0μm -41μm -32μm -18μm -24μm +40μm +48μm -41μm +42μm +35μm +15μm -25μm -20μm

[0041] The following table 1 and Figure 1 、 Figure 3 and Figure 4 Step 1 and step 2 are described. This application only analyzes the three lines of image strips corresponding to the first laser 105-1 exposure. Figure 1 The other three lasers 105-2 to 105-4 move synchronously with the laser 105-1, emit light synchronously, and are turned off synchronously. Moreover, the 15 compensation values ​​corresponding to each laser are exactly the same. Therefore, there is no need to analyze the three lines of image strips corresponding to their exposure.

[0042] definition Figure 1 The horizontal movement direction of the laser 105-1 is the positive direction. The laser 105-1 first exposes the first row of image strips from right to left, and then Figure 1 Under the control of the control module 9, the camera moves upward a distance h, moving from left to right, exposing the second row of image strips. Then, under the control of the control module 9, the camera moves upward a distance h, continuing to move from right to left, exposing the third row of image strips. Here, h is the distance between two adjacent rows of image strips in the vertical direction.

[0043] refer to Figure 2 、 Figure 4 and Table 1, Figure 4Exposure points A11, A12, A13, A14, A15, and A16 in the first row of image strips exposed by laser 105-1 are the six dividing points that divide the first row of image strips into five image segments. They are also the preset exposure points. The length of each image segment is L, which is equal to the theoretical exposure length of the laser per interval T. These five image segments are, in order: image segment A11A12, image segment A12A13, image segment A13A14, image segment A14A15, and image segment A15A16. Theoretically, when laser 105-1 sequentially exposes the first and last two pixels of each image segment of the first row of image strips A11A16 from right to left, the preset dwell position of laser 105-1 coincides with exposure points A11, A12, A13, A14, A15, and A16. However, based on the mechanical errors and signal transmission errors existing in the laser direct writing equipment mentioned in the background technology, when the laser 105-1 exposes the five image segments of the first row of the image strip, the actual exposure points corresponding to the six preset exposure points are B11, B12, B13, B14, B15, and B16. This means that among the six actual exposure points, except for the first starting actual exposure point B11, which must be required to coincide with the corresponding stop position A11, whether the remaining five coincide with the corresponding pre-stop positions is random: some are on the left of the corresponding pre-stop positions, and some are on the right of the corresponding pre-stop positions, for example: B12 is on the right of A12, B13 is on the right of A13, B14 is on the left of A14, B15 is on the left of A15, and B16 is on the left of A16. The actual length of any image segment of any row of image strips exposed by the laser is defined by the following method: from the time when the laser exposes the first pixel point of the Xth image segment of any Pth row of image strips to the time when the control module mistakenly believes that the laser has exposed the last exposure point of the image segment, the actual displacement Lpx of the laser movement, wherein the actual exposure position of the first pixel point of the image segment and the preset exposure position are defined as overlapping. Wherein, P is any natural number between 1 and M, and X is any natural number between 1 and N. For example, in the present application, the number of image strips M exposed by any laser is exemplarily 3, then P can be 1, 2, 3. N represents the number of image segments into which each row of image strips is exemplarily divided. In the present application, N is exemplarily 5. Therefore, X can be any natural number between 1 and 5. Exemplarily, the actual lengths of the 5 image segments of the first row of image strips exposed are L11, L12, L13, L14, and L15, respectively. Some of these values ​​are larger than L, and some are smaller than L. See Figure 4 .

[0044] refer to Figure 4When the laser 105-1 exposes the first image segment (N=1) of the first row of image strips (P=1), the actual displacement L11 is the length from the first exposure point A11 of the first image segment to the actual stop position B12 of the laser when the control module 109 mistakenly believes that the laser 105-1 has finished exposing the last exposure point A12 of the first image segment (A12 is also the first exposure point of the second image segment of the first row of image strips). The laser 105-1 exposes the second image segment (N=2) of the first row of image strips (P=1), and the actual displacement L12 it passes through is the length from the first exposure point A12 of the second image segment (also the last exposure point of the first image segment) to the actual stop position B13 of the laser when the control module 109 mistakenly believes that the laser 105-1 has finished exposing the last exposure point A13 of the second image segment; the laser 105-1 exposes the fifth image segment (N=5) of the second row of image strips (P=2), and the actual displacement L25 it passes through is the length from the first exposure point A25 of the fifth image segment of the second row of image strips (also the last exposure point of the fourth image segment of the second row of image strips) to the actual stop position B26 of the laser 105-1 when the control module 109 mistakenly believes that the laser 105-1 has finished exposing the last exposure point A26 of the fifth image segment of the second row of image strips.

[0045] Define the difference d between the actual displacement Lpx of the laser and the length L of the image segment from the first pixel point of the Xth image segment of any Pth row image strip to the time when the control module mistakenly believes that the laser has exposed the last exposure point of the Xth image segment PX = Lpx - L, and this difference is the compensation value. It is understood that in this application, when any laser exposes M image strips, and each image strip is evenly divided into N image segments, a total of M*N compensation values ​​are required. For example, when M is 3 and N is 5, each laser requires 15 compensation values. Table 1 shows the 15 compensation values ​​required for exposure by laser 105-1.

[0046] Continue to combine Figure 1 、 Figure 4 And Table 1, describes Figure 1 How can any laser of the laser direct writing device 100 accurately expose the corresponding 3 lines of image strips according to 15 compensation values ​​to improve the image exposure accuracy.

[0047] When laser 105-1 (hereinafter referred to as the first laser) exposes the first row of image strips, it exposes five image segments in sequence from right to left according to the five compensation values ​​at the bottom of Table 1: the control module controls the first laser to start exposing from the first exposure point A11 on the far right (in this application, the exposure point and the pixel point occupy the same position). When it moves to the left to position B12, it is still a distance d11 (d11 = L11-L) away from the preset position A12. The control module mistakenly believes that the first laser has reached the preset position A12 and has exposed the last pixel point of the first image segment of the first row of image strips. If the light output of the first laser is not compensated for the remaining distance d11, the control module of the laser direct writing device will control the first laser to start exposing the second image segment, which will cause an exposure error. Therefore, when the first laser moves left to position B12, it is necessary to control the first laser to continue rightward to exposure point A12 according to the 20μm compensation value provided in Table 1, and perform compensated exposure on the portion of the image between B12 and A12. In Table 1, the value of -20μm for d11 is merely illustrative; it indicates that the control module mistakenly determined that the first laser had reached the preset position even though it had not yet reached the preset position during its forward movement. Similarly, when the first laser exposes the second segment of the first image strip, it also needs to expose the remaining portion of the image between B13 and A13 according to the compensation value of d12 = -25μm. When exposing the third image segment of the first row of the image strip, the first laser starts at the first pixel A13 of the third image segment and moves to the left for exposure. When it moves to the last pixel A14 of the third image segment, the control module mistakenly believes that the first laser has not reached pixel A14 and continues to control the first laser to move to the left. The first laser does not reach pixel A14 until it exceeds pixel A14 by a distance d13 (d13 = L13 - L) and reaches pixel B14. Only then does the control module mistakenly believe that the first laser has reached pixel A14. Obviously, the actual position reached by the first laser has exceeded pixel A14. If the image of the excess length d13 of A14B14 is not exposed, the image of A14B14, which originally belonged to the fourth image segment A14A15 and has a length of d13, will be exposed as the latter part of the third image segment A13A14 of the first row of the image strip, resulting in an exposure error. Therefore, to improve image exposure accuracy, when the first laser is exposing the third image segment A13A14 of the first row of the image strip, the control module needs to control the first laser to terminate exposure at exposure point A14, 15 μm before exposure point B14. In Table 1, d13 = +15 μm, where + indicates that the first laser has already exceeded the preset position during forward movement, but the control module mistakenly determines that it has not yet reached the preset position.Similarly, when exposing the fourth image segment A14A15 of the first image strip, the first laser was originally scheduled to terminate exposure after exposing the last pixel A15. However, the control module mistakenly interpreted pixel A15 as being located at the front of the image segment B15. This means that the 35μm segment A15B15, originally part of the fifth image segment A15A16, is exposed as part of the fourth image segment. Therefore, the control module controls the first laser to terminate exposure of the fourth image segment at A15. The previous image segment A14B14 should be processed as the image corresponding to the fourth image segment A14A15. Next, the first laser exposes the fifth image segment of the first image strip. The first laser was originally scheduled to terminate exposure after exposing the last pixel A16. However, the control module mistakenly interpreted pixel A16 as being located at the front of the image segment B16. This means that the first laser traveled an additional distance d15 = 42μm before stopping. Therefore, the first laser must terminate exposure within the distance A16B16. For the previous A15B15 segment, the corresponding part of the fifth segment should be exposed. Figure 4 It can be seen from FIG1 that when the first laser exposes the five image segments of the first row of image strips, the total distance traveled by the first laser is d15=42 μm longer than the total length 5L of the first image strip.

[0048] Figure 4 , the actual exposure points corresponding to the six preset exposure points A21, A22, A23, A24, A25, and A26 of the second row of image strips are: B21, B22, B23, B24, B25, and B26. The first pixel point A21 on the left needs to be set to be consistent with the actual exposure point, that is, A21 / B21 coincide. The actual exposure points corresponding to the six preset exposure points A31, A32, A33, A34, A35, and A36 of the third row of image strips are: B31, B32, B33, B34, B35, and B36. The first preset exposure point A31 on the right needs to be set to be consistent with the actual exposure point, that is, A31 / B31 coincide.

[0049] refer to Figure 4After the first laser has exposed all image segments of the first row of image strips, the control module controls the first laser to move upward a distance h from position B16 to position A20, preparing to expose the second row of image strips. It is understood that at this point, the first laser is also a distance d15 from the first exposure point A21 on the leftmost side of the second row of image strips. Before the first laser exposes the second row of image strips, the control module needs to move the first laser horizontally to the right a distance d15, while not emitting light, to the first exposure point A21 on the leftmost side of the second row of image strips. Then, based on the five compensation values ​​d21-d25 for the second row of image strips provided in Table 1, the control module sequentially exposes the five image segments of the second row of image strips, following the same principle as for sequentially exposing the five image segments of the first row of image strips. It should be noted that when exposing the fifth image segment A25A26 of the second row of the image strip, in the A25B25 portion, the first laser needs to switch from exposing the fourth image segment A24A25 to exposing the fifth image segment; in the B26A26 portion, the first laser needs to continue emitting light based on the compensation value d25 = -41μm to expose the remaining part of the fifth image segment A25A26.

[0050] After the first laser exposes the last pixel A26 on the right side of the second row of image strip, the control module controls the first laser to move upward a distance h based on the position of pixel A26, and locates at the first pixel A31 on the rightmost side of the third row of image strip. Then, based on the five compensation values ​​d31-d35 of the third row of image strip provided in Table 1, the five image segments of the third row of image strip are exposed in sequence in the same way as the five image segments of the first row of image strip are exposed in sequence.

[0051] For the value of L, 100 mm is preferred in this application, and it can also be 150 mm or 200 mm, and generally an integer multiple of 100 mm is selected. When L is 100 mm, the range of any compensation value is -50 μm ≤ d PX ≤50μm.

[0052] Each of the M image strips exposed by each laser is divided into N image segments, resulting in M*N image segments. Based on the M*N compensation values ​​corresponding to the M*N image segments, the M*N image segments are accurately exposed. This solves the problem of inconsistency between the actual path of the laser and the position corresponding to the image strip to be exposed caused by mechanical reasons and signal transmission reasons of the laser direct writing device when the laser is exposing the image strip, thereby improving the image exposure accuracy.

[0053] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for improving laser exposure accuracy, used in laser direct writing equipment, characterized in that: include: Step 1: Obtain M rows of image strips to be exposed corresponding to any laser of the laser direct writing device, and each row of image strips is equally divided into N image segments, totaling M*N compensation values; Step 2: The control module of the laser direct writing device controls the laser to emit light according to the M*N compensation values, exposing the M lines of image strips row by row in a sequence from the beginning to the end, so that the M lines of image strips are accurately exposed; In step 1, the N compensation values ​​in any row of the image strip are calculated as follows: Step 11, defining the length L of each image segment of any P-th image strip in the M image strips to be equal to the theoretical exposure length of the laser within each time interval T; Step 12: obtaining the actual displacement Lpx of the laser when sequentially exposing any X-th image segment of N image segments of any P-th row of image strips, and obtaining a total of N actual displacements Lpx; Step 13: Subtract the N actual displacements Lpx from the length L of the corresponding image segment to obtain N difference values ​​dPX, dPX=Lpx-L. The N difference values ​​dPX are the N compensation values ​​for any P-th row of the image strip. Wherein, X is any natural number from 1 to N, and P is any natural number from 1 to M; The M rows of image strips in step 1 are of equal length and are vertically distributed in a column; all lasers of the laser direct writing device are in the same vertical position and move, light up and turn off synchronously.

2. The method according to claim 1, wherein Step 2 specifically includes: Step 21: Select any one of the lasers as the laser at the bottom and define it as the first laser. The control module controls the first laser to sequentially expose N image segments of the first row of image strips at the bottom from right to left in combination with N compensation values. Step 22: The control module moves the first laser upward by h based on the actual stopping position of the first laser after exposing the first row of image strips. The control module sequentially exposes N image segments of the second row of image strips from left to right, combining the N compensation values ​​of the second row of image strips. Step 23: When the first laser exposes any image strip from the third row to the Mth row, the control module uses the actual stopping position of the first laser after exposing the previous image strip in any image strip as a reference, moves the first laser upward by h, and sequentially exposes N image segments in any image strip in combination with the N compensation values ​​corresponding to the first laser for the image strip in any row. When the first laser exposes each image segment, the initial exposure position of the first laser needs to be set to coincide with the starting point of each image segment; h is the vertical distance between two adjacent rows of image strips.

3. The method according to claim 2, wherein When the first laser exposes the second row of image strips to the Mth row of image strips, the laser does not emit light when it moves horizontally from the actual stop position to the horizontal displacement of the first pixel point of the first image segment of the row of image strips.

4. The method according to claim 1, wherein: If dPX is negative, it indicates that when the laser is exposing any image segment of any P-th row image strip, it mistakenly believes that the exposure of any image segment is completed when the laser is still a distance dPX away from the end point of the image segment, and the control module needs to control the laser to continue exposing the remaining image portion with a length of dPX; if dPX is positive, it indicates that the laser is mistakenly believed to have reached the end point of any image segment when it continues to move forward a distance dPX after exceeding the end point of any image segment, and the control module needs to control the laser to end exposure dPX in advance and switch to exposing the next image segment.

5. The method according to claim 1, wherein The direction from the starting point to the end point of any image segment of any row of image strips is the movement direction of the laser exposing the row of image strips.

6. The method according to claim 1, wherein The value of L is 100 mm, -50 μm ≤ dPX ≤ 50 μm.

Images