Calibrate the printing process

Abstract

The present invention discloses a calibration printing process, comprising: 1) preparing a standard draft and a sample draft, establishing coordinate systems for each of the standard draft and the sample draft, and marking the standard draft and the sample draft, with reference points set on each of the standard draft and the sample draft; 2) placing the standard draft and the sample draft on a screen exposure machine and fixing them in position; 3) using a CCD camera of the screen exposure machine to obtain the positions of the marking points on the standard draft and the sample draft; 4) comparing the marking points of the sample draft with the marking points of the standard draft to calculate the deformation of the sample draft; 5) calculating compensation parameters based on the deformation and performing deformation compensation on the pattern to be printed; 6) removing the sample draft, placing a screen, and performing screen printing after the printer obtains the compensation parameters. This process can achieve calibration of pattern printing between different steps in the printing process.

Description

Technical Field

[0001] The present invention relates to the field of printing, in particular to a calibration printing process. Background Art

[0002] During the printing process, the same pattern often requires different printing processes. For example, a portion of a pattern may be offset printed first, followed by screen printing of the remaining pattern. In this case, the offset printed pattern must accurately match the screen printed pattern. During the offset printing process, the paper or other material being printed will expand and contract during the printing process. The screen printing plate is made according to the original size of the original document before deformation. Therefore, when printed according to the original plate, the pattern will be distorted. In the existing art, screen printing plates are typically made using film. The film is cut according to the image unit, and then compared based on the actual deformation of the offset printed product. The film is then reassembled and used to make the plate. Because screen printing plates made using film inherently have poor precision, the cutting and splicing of film is completely manual, making it difficult to guarantee accuracy and relying heavily on human experience. Film-free screen exposure processes, such as computer-to-plate (CTP), currently do not have a solution to this problem.

[0003] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0004] The object of the present invention is to provide a calibration printing process, which can achieve calibration of pattern printing between different steps in the printing process.

[0005] To achieve the above objectives, an embodiment of the present invention provides a calibration printing process, comprising:

[0006] 1) preparing a standard draft and a sample draft, establishing coordinate systems for the standard draft and the sample draft respectively, and marking the standard draft and the sample draft, with reference points set on the standard draft and the sample draft;

[0007] 2) placing the standard draft and the sample draft on the screen exposure machine respectively and fixing them in position;

[0008] 3) The CCD camera of the screen exposure machine obtains the positions of the marking points on the standard draft and the sample draft;

[0009] 4) comparing the marking points of the sample draft with the marking points of the standard draft to calculate the deformation amount of the sample draft;

[0010] 5) Calculating compensation parameters based on the deformation amount and performing deformation compensation on the pattern to be printed;

[0011] 6) Remove the sample, place the screen, and the printing machine obtains the compensation parameters before screen printing.

[0012] In one or more embodiments of the present invention, in step 2), when the standard draft and the sample draft are placed on the screen exposure machine, the reference points and coordinate axes of the standard draft and the sample draft completely coincide.

[0013] In one or more embodiments of the present invention, obtaining the position of the marking point in step 3) includes: obtaining the position of the marking point and the reference point of the standard draft and obtaining the position of the marking point and the reference point of the sample draft.

[0014] In one or more embodiments of the present invention, step 4) includes: calculating the distance between the marking point of the standard draft and the corresponding marking point of the sample draft, and using the distance to calculate the deformation between the sample draft and the standard draft.

[0015] In one or more embodiments of the present invention, there are multiple marking points for the standard draft and the sample draft.

[0016] In one or more embodiments of the present invention, when the standard draft and the sample draft are set with multiple marking points in step 4), the distances between the marking points of the standard draft and the corresponding marking points of the sample draft are calculated separately, and multiple sets of distances are obtained to calculate the deformation amount between the sample draft and the standard draft.

[0017] In one or more embodiments of the present invention, when processing the multiple groups of distances, the deformation amount is selected from one of the average value, median value or mode value of the multiple groups of distances.

[0018] In one or more embodiments of the present invention, the origin of the coordinate system is located at the edge or center of the standard draft and the sample draft.

[0019] In one or more embodiments of the present invention, the reference point is located on a coordinate axis of the coordinate system.

[0020] In one or more embodiments of the present invention, the reference point is the origin of the coordinate system.

[0021] Compared with the prior art, the calibration printing process according to the embodiment of the present invention can read the pattern after offset printing through the CCD camera of the screen exposure machine to obtain the deformation amount after offset printing and before screen printing, so as to calibrate the screen printing pattern before screen printing to achieve accurate pattern printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of a calibration printing process according to one embodiment of the present invention. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0024] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0025] like Figure 1 As shown, a calibration printing process according to a preferred embodiment of the present invention includes:

[0026] 1) Create a standard draft and a sample draft, where the sample draft is the pattern that will be deformed after printing, and the standard draft is the pattern that will not be deformed. After the standard draft and the sample draft are completed, a coordinate system needs to be established for each of them, and both the standard draft and the sample draft need to be marked, and reference points are set on the standard draft and the sample draft.

[0027] 2) Place the standard draft and the sample draft separately on the screen exposure machine. The standard draft and the sample draft are positioned and fixed using the screen exposure machine's vacuum suction mechanism. In practice, the standard draft is placed on the screen exposure machine first, and the sample draft is placed after the screen exposure machine has processed the standard draft. When the standard draft and the sample draft are placed on the screen exposure machine one after the other, the reference points of the standard draft and the sample draft must completely coincide with the orthographic projections of the coordinate axes on the screen exposure machine.

[0028] 3) The screen exposure machine's CCD camera captures the positions of the marking points on the master and sample drafts. In this step, the CCD camera sequentially captures the positions of the marking points and reference points on the master draft, and the reference points and reference points on the sample draft. The CCD camera captures the reference points of the master and sample drafts separately to ensure that when the master and sample drafts are compared, there are no positional deviations between the two patterns, which could lead to large errors in the subsequent calculation of the marking points.

[0029] 4) Compare the marking points of the sample draft with the marking points of the standard draft, and calculate the deformation of the sample draft. In this step, the distance between the marking points of the standard draft obtained in step 3) and the corresponding marking points of the sample draft is mainly calculated, and the deformation between the sample draft and the standard draft is calculated by combining the distance with the computer program and the relevant algorithm. Among them, there can be only one marking point for the standard draft and the sample draft. In order to accurately obtain the deformation amount, a plurality of marking points are provided on the standard draft, and a plurality of corresponding marking points are provided on the sample draft. When the standard draft and the sample draft are provided with multiple marking points, the distance between the marking points of the standard draft and the corresponding marking points of the sample draft needs to be calculated separately, and multiple sets of distances are obtained to calculate the deformation amount between the sample draft and the standard draft. When processing multiple sets of distances, the deformation amount is obtained by processing the average value, median value or mode value of the multiple sets of distances.

[0030] 5) Calculate the compensation parameters based on the deformation amount and perform deformation compensation on the pattern to be printed;

[0031] 6) Remove the sample, place the screen, and the printing machine obtains the compensation parameters before screen printing.

[0032] In the above steps, the origin of the coordinate system is located at the edge or center of the standard and sample drafts. The reference point is also located on the coordinate axis of the coordinate system. For ease of processing, the reference point can be selected as the origin of the coordinate system.

[0033] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A calibration printing process, characterized in that include: 1) preparing a standard draft and a sample draft, establishing coordinate systems for the standard draft and the sample draft respectively, marking the standard draft and the sample draft, and setting reference points on the standard draft and the sample draft; 2) Placing the standard draft and the sample draft separately on a screen exposure machine and securing them in position; wherein, the standard draft is placed on the screen exposure machine first, and the sample draft is placed after the screen exposure machine has processed the standard draft; when the standard draft and the sample draft are placed on the screen exposure machine successively, the reference points of the standard draft and the sample draft completely coincide with the orthographic projections of the coordinate axes on the screen exposure machine; the standard draft and the sample draft are secured in position by vacuum adsorption using the mechanism of the screen exposure machine; 3) The CCD camera of the screen exposure machine obtains the positions of the marking points on the standard draft and the sample draft; 4) Comparing the marking points of the sample draft with the marking points of the standard draft to calculate the deformation amount of the sample draft; 5) Calculating compensation parameters based on the deformation amount and performing deformation compensation on the pattern to be printed; 6) Remove the sample, place the screen, and the printing machine obtains the compensation parameters before screen printing.

2. The calibration printing process according to claim 1, wherein: In step 2), when the standard draft and the sample draft are placed on the screen exposure machine, the reference points and coordinate axes of the standard draft and the sample draft completely coincide with each other.

3. The calibration printing process according to claim 1, wherein: Acquiring the positions of the marking points in step 3) includes: acquiring the positions of the marking points and the reference points of the standard draft and acquiring the positions of the marking points and the reference points of the sample draft.

4. The calibration printing process according to claim 1, wherein: Step 4) includes: calculating the distance between the marking point of the standard draft and the corresponding marking point of the sample draft, and using the distance to calculate the deformation between the sample draft and the standard draft.

5. The calibration printing process according to claim 1, wherein: There are multiple marking points for the standard draft and the sample draft.

6. The calibration printing process according to claim 5, wherein: Step 4) When the standard draft and the sample draft are set with multiple marking points, the distances between the marking points of the standard draft and the corresponding marking points of the sample draft are calculated respectively to obtain multiple sets of distances to calculate the deformation between the sample draft and the standard draft.

7. The calibration printing process according to claim 6, wherein: When processing the multiple sets of distances, the deformation amount is selected from one of the average value, median value or mode value of the multiple sets of distances.

8. The calibration printing process according to any one of claims 1 to 7, characterized in that: The origin of the coordinate system is located at the edge or center of the standard draft and the sample draft.

9. The calibration printing process according to claim 8, wherein: The reference point is located on the coordinate axis of the coordinate system.

10. The calibration printing process according to claim 9, wherein: The reference point is the origin of the coordinate system.

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