Graph edge aiming method
By forming two symmetrical images on the imaging device and calculating their intersection as the aiming point, the inaccuracy problem of graphic edge blur is solved, and high-precision graphic edge aiming is achieved.
Patent Information
- Application Number
- CN202411833988.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-03-07
AI Technical Summary
When the existing automatic graphic edge aiming method exists in the processing error of the graphic target, it is easy to cause blurred edges of the graphic to be measured, which in turn affects the accuracy of the aiming.
The edge of the measured pattern is formed on the imaging device through the objective lens group, two independent fully symmetric images of the left and right sides on the imaging device, and the intersection of the symmetric center line and the geometric center point of these images is calculated as the aiming point.
High-precision aiming of the edge of the graph is achieved, reducing the influence of random errors, and improving the repetition and accuracy of measurements.
Smart Images
Figure CN119575689A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of metrology calibration, and in particular relates to a graphic edge aiming method. Background Art
[0002] The existing automatic graphic edge aiming method basically adopts the combination of microscope + imaging device such as CCD. First, the objective lens is used to focus on the edge of the measured graphic to be aimed at, and the measured edge will be imaged on the imaging device. Then, a certain image processing algorithm is used to extract and process the edge of the measured graphic, and finally the measurement point to be aimed at is obtained. Therefore, the image edge must be clear enough, and the shape error of the edge of the measured graphic must be good enough to obtain accurate measurement results. However, due to the existence of graphic target processing errors, the edges of the measured graphic are inevitably blurred, and sometimes it may not be possible to accurately aim. Summary of the invention
[0003] The object of the present invention is to provide a method for aiming at a graphic edge, which can achieve high-precision aiming at a graphic edge.
[0004] In order to achieve the above object, one aspect of the present invention provides a method for aiming at an edge of a graphic, comprising:
[0005] The edge of the measured pattern is made to form two independent completely symmetrical images on the left and right on the imaging device through the objective lens group;
[0006] The symmetric center lines of the left and right images are calculated, the geometric center points of the two images are calculated respectively, and the intersection point of the line connecting the geometric center points of the two images and the symmetric center line is calculated as the aiming point.
[0007] Preferably, the objective lens group includes a first beam splitter group, a pentaprism, a reflector and a second beam splitter group.
[0008] The measured pattern is directly irradiated onto the imaging device through the first beam splitter group to form a first path of imaging;
[0009] The measured pattern is reflected by the first beam splitter group, and then reflected twice by the pentaprism before being emitted to the reflector. After being reflected by the reflector, it is reflected by the first beam splitter group again and then irradiated onto the imaging device to form a second path of imaging.
[0010] The first imaging channel and the second imaging channel are superimposed on the imaging device to obtain two independent completely symmetrical images.
[0011] Preferably, the first beam splitter group and the second beam splitter group are semi-transparent and semi-reflective mirrors.
[0012] Preferably, the imaging device is CCD or CMOS.
[0013] Preferably, the objective lens group and the imaging device form a refractive and reflective optical path, a reflective optical path combination or a refractive optical path combination.
[0014] The graphic edge aiming method of the above aspect of the present invention can achieve high-precision aiming of the graphic edge. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:
[0016] Figure 1 is a principle diagram of an optical path of a method for aiming at a pattern edge according to an embodiment of the present invention;
[0017] Figure 2 It is an algorithm principle diagram of a graphics edge aiming method according to an embodiment of the present invention. DETAILED DESCRIPTION
[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below 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 creative work are within the scope of protection of the present invention.
[0019] An embodiment of the present invention provides a method for aiming at the edge of a graphic, which uses an objective lens group to form two independent completely symmetrical images on the left and right of the edge of the graphic to be measured on an imaging device, calculates the symmetry center lines of the two images, calculates the geometric center points of the two images respectively, and calculates the intersection of the line connecting the geometric center points of the two images and the symmetry center line as the aiming point.
[0020] The objective lens group is used to produce necessary magnification, reduction, collimation, etc. of the light, and can be various objective lens groups such as microscope objective lens, telescope objective lens, interference objective lens, collimation objective lens, etc., as long as it can realize that the edge of the measured figure forms two independent completely symmetrical images. The imaging device can be any photoelectric imaging receiving device such as CCD, CMOS, etc. The optical path formed by the objective lens group and the imaging device includes but is not limited to refraction and reflection optical paths, and can also be a combination of reflection optical paths and refraction optical paths, as long as mirror imaging can be performed. The optical path can be a non-coaxial optical path or a coaxial optical path.
[0021] In one embodiment, Figure 1As shown on the left side of the figure, when the measured figure 1 passes through the first beam splitter group 2, two images are generated: the first image is directly irradiated onto the imaging device 5 through the first beam splitter group 2; the second image is reflected by the first beam splitter group 2, and then reflected twice by the pentaprism 3 before being emitted to the reflector 4, and after being reflected by the reflector 4, it is reflected by the second beam splitter group 6 and then irradiated onto the imaging device 5. At this time, the first image and the second image are superimposed on the imaging device 5 at the same time, and images in two directions, one positive and one negative, are obtained, that is, two independent completely symmetrical images, as shown in FIG. Figure 1 Shown on the right.
[0022] At this time, the two images are exactly the same and symmetric, so it is easy to calculate their symmetry center line. Figure 2 As shown, the symmetric center line C of the left and right images can be calculated, and then the geometric center point A of the left image and the geometric center point B of the right image can be calculated respectively, and the straight line AB can be obtained by connecting them. Then the intersection of line AB and line C can be calculated, which is the aiming point 0 required for this aiming.
[0023] Since the graphic edge aiming method of the embodiment of the present invention does not use a certain point on the graphic edge as the aiming point, but uses the average value of the entire image edge as the measurement point, the use of the average value as the aiming result greatly reduces the influence of random errors, thereby improving the repeatability of the measurement and the aiming accuracy.
[0024] In the above embodiment, the first beam splitter group 2 and the second beam splitter group 6 can be semi-transparent and semi-reflective mirrors, but are not limited to semi-transparent and semi-reflective mirrors, and can also be reflective mirrors, dichroic mirrors, various prism combinations, prism and reflective mirror combinations. The pentaprism 3 can also be other optical structures that can play the same role.
[0025] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.
Claims
1. A method for aiming at the edge of a graphic, characterized in that: include: The edge of the pattern to be measured is made to form two independent completely symmetrical images on the left and right on the imaging device through the objective lens group; The symmetric center lines of the left and right images are calculated, the geometric center points of the two images are calculated respectively, and the intersection point of the line connecting the geometric center points of the two images and the symmetric center line is calculated as the aiming point.
2. The method according to claim 1, characterized in that: The objective lens group includes a first beam splitter group, a pentaprism, a reflector, and a second beam splitter group. The measured pattern is directly irradiated onto the imaging device through the first beam splitter group to form a first path of imaging; The measured pattern is reflected by the first beam splitter group, and then reflected twice by the pentaprism before being emitted to the reflector. After being reflected by the reflector, it is reflected by the first beam splitter group again and then irradiated onto the imaging device to form a second path of imaging. The first imaging channel and the second imaging channel are superimposed on the imaging device to obtain two independent completely symmetrical images.
3. The method according to claim 2, characterized in that The first beam splitter group and the second beam splitter group are semi-transparent and semi-reflective mirrors.
4. The method according to any one of claims 1 to 3, characterized in that The imaging device is CCD or CMOS.
5. The method according to claim 1, characterized in that The objective lens group and the imaging device form a refractive and reflective light path, a reflective light path combination or a refractive light path combination.