A Z-axis zero position calibration method and measurement system for a fully automatic imager

Abstract

The present invention provides a Z-axis zero position calibration method for a fully automatic imager, which includes the following steps: S1, assuming that the upper surface of a loading platform is the theoretical coordinate system zero point Z, the theoretical focusing height of an optical microscope tube is Z0, and the distance between Z and Z0 is C; S2, power-on initialization, turning on the "one-key zero return" function of the measurement software, the optical imaging component scanning and searching the upper surface of the loading platform in the upper and lower areas of Z0 and taking a plurality of pictures, and the counting grating ruler collecting the Z-axis coordinate value information of each picture; S3, the measurement software extracts the clearest pictures, these pictures are spatially stacked in the height direction and form a height area, within this area, the software fits a peak point in a parabolic manner according to the clarity of each picture, the Z-axis coordinate value corresponding to the peak point is the actual focusing height Zn, and the distance between point Z and Zn is calculated to be Cn; S4. The Z-axis lifting module is offset along the Z axis at the current Zn position by ‑△C=Cn‑C, thereby correcting the theoretical coordinate system zero point Z.

Description

Technical field

[0001] The present invention relates to the technical field of image measuring equipment, and in particular to a Z-axis zeroing position calibration method and a measuring system for a fully automatic imager. [Background Technology]

[0002] The fully automatic image measuring machine is an artificial intelligence-based, modern optical non-contact measuring instrument developed based on digital image (CNC) measuring instruments. It inherits the excellent motion accuracy and motion control performance of digital instruments and integrates the design ingenuity of machine vision software, making it one of the most cutting-edge optical dimensional inspection equipment available today.

[0003] The fully automatic image measuring instrument realizes artificial intelligence through automatic focus and area search, target locking, edge extraction, and fuzzy calculation of matching points. It can automatically correct the offset caused by workpiece differences and positioning differences to achieve accurate point selection. It has high-precision repeatability, improves the efficiency of batch measurement of workpieces, and meets the needs of industrial sampling and large-scale inspection.

[0004] When large-volume inspections are required, multiple fully-automated image measuring machines are often required to measure the same product to meet production schedules and production capacity, often with extremely tight product changeover times. Traditional image measuring methods, due to multiple factors such as machining and assembly errors, can cause inconsistencies in the theoretical Z-axis zero points between different fully-automated image measuring machines after the Z-axis is clearly focused. This makes it impossible to run measurement programs using the same measurement reference. This often requires repeated programming and debugging on each fully-automated image measuring machine for the corresponding product before automatic measurement can be performed. Alternatively, a significant amount of time and effort is required to slowly adjust the mounting position of the counting scale and optical microscope tube to ensure alignment with the measurement reference when focused. However, this method is not only costly and inefficient, but also, due to the principle of Moore's Law, it is impossible to achieve nearly identical Z-axis zero points across all fully-automated image measuring machines using traditional methods.

[0005] Therefore, it is necessary to provide a new Z-axis zero position calibration method and measurement system for a fully automatic imager to solve the above technical problems. [Summary of the invention]

[0006] The object of the present invention is to provide a low-cost, high-efficiency Z-axis zero position calibration method and measurement system for a fully automatic imager, so as to solve the problems in the related art.

[0007] In order to achieve the above-mentioned object, the present invention provides a Z-axis zero position calibration method for a fully automatic imager, wherein the fully automatic imager includes a loading platform, an optical imaging component located above the loading platform, a Z-axis lifting module capable of driving the optical imaging component to move along the Z-axis direction, and a counting grating ruler capable of outputting Z-axis absolute coordinate values, wherein the optical imaging component includes an optical microscope tube, a CCD, and a light source, and wherein the method comprises the steps of: S1, setting the upper surface of the loading platform as the theoretical coordinate system zero point Z, the theoretical focusing height of the optical microscope tube as Z0, and the distance between the theoretical coordinate system zero point Z and the theoretical focusing height Z0 as C (C is a constant); S2, after the fully automatic imager is powered on and initialized, opening the measurement software and clicking the "one-key return to zero" function, the Z-axis lifting module drives the optical imaging component to automatically scan and search the upper surface of the loading platform in the upper and lower areas of the theoretical focusing height Z0 and take a plurality of pictures, and the counting grating ruler collects the Z values ​​of the plurality of pictures. Axis absolute coordinate value, each picture has a corresponding Z-axis coordinate value information; S3, the measurement software analyzes the clearest one of the several pictures, and obtains the corresponding actual focusing height Zn, and calculates the distance between the theoretical coordinate system zero point Z and the actual focusing height Zn as Cn; S4. The measurement software controls the Z-axis lifting module to offset the current actual focusing height Zn position along the Z axis by -△C=Cn-C, thereby correcting the theoretical coordinate system zero point Z of the Z axis.

[0008] More preferably, in step S3, the measurement software analyzes the several pictures, extracts the clearest pictures, and makes the pictures overlap in the height direction to form a height area. In the height area, the measurement software fits a peak point in a parabolic manner according to the clarity of each picture, and the Z-axis coordinate value corresponding to the peak point is the actual focusing height Zn.

[0009] More preferably, in the step S2, the optical imaging component smoothly scans the upper surface of the object carrying platform along a fixed interval in the upper and lower regions of the theoretical focusing height Z0, and the fixed interval is 0.1 micrometer.

[0010] More preferably, the CCD mechanism is fixed to the upper end of the optical microscope tube, the light source is fixed to the lower end of the optical microscope tube, and the light source is located above the object loading platform.

[0011] More preferably, the Z-axis lifting module includes a Z-axis transmission assembly and a Z-axis guide rail, and the counting grating ruler is fixed to the Z-axis lifting module.

[0012] More preferably, the fully automatic imager also includes a base, an XY motion platform arranged on the base, and the XY motion platform includes a first movable platform located on the upper layer, a second movable platform located in the middle layer, an X-axis transmission assembly, an X-axis guide rail, a Y-axis transmission assembly and a Y-axis guide rail.

[0013] More preferably, the X-axis transmission assembly is arranged between the first movable platform and the second movable platform, and the Y-axis transmission assembly is arranged between the second movable platform and the base.

[0014] More preferably, the optical imaging assembly further comprises a bracket, and the bracket comprises a first fixing portion fixed to the Z-axis lifting module, a second fixing portion clamping the optical microscope tube, and a third fixing portion.

[0015] More preferably, the light source includes a light panel provided with a plurality of light bulbs and a light shield.

[0016] The present invention also provides a measuring system, which adopts a Z-axis zeroing position calibration method of a full-automatic imager.

[0017] The technical effect of the present invention is that the Z-axis theoretical coordinate system zero points of multiple fully automatic imagers can be corrected to a unified theoretical coordinate system zero point, which is beneficial for large-scale testing without the need to reprogram and debug each fully automatic imager, reducing manpower and time costs and improving test efficiency.

Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0019] Figure 1 It is a three-dimensional composite diagram of the fully automatic imaging instrument of the present invention;

[0020] Figure 2 It is a partial assembly diagram of the fully automatic imaging instrument of the present invention;

[0021] Figure 3 yes Figure 1 The cross-section along AA is shown;

[0022] Figure 4 yes Figure 2 A partial composite view from another perspective is shown;

[0023] Figure 5 This is a flow chart of a Z-axis zeroing calibration method for a fully automatic imaging device of the present invention;

[0024] Figure 6 The present invention is a flowchart of another embodiment of a method for calibrating the Z-axis zero position of a fully automatic imager. [Specific implementation method]

[0025] 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.

[0026] Please refer to Figures 1 to 4 As shown, a fully automatic imaging device 100 includes a base 1, an XY motion platform 2, a loading platform 3, an optical imaging component 4, a Z-axis lifting module 5, a counting grating ruler 6, an outer cover 7, and a column 8.

[0027] The XY motion platform 2 is fixed to the base 1 and includes a first movable platform 21 located on the upper layer, a second movable platform 22 located in the middle layer, an X-axis transmission assembly 23, an X-axis guide rail 24, a Y-axis transmission assembly 25, and a Y-axis guide rail 26.

[0028] Specifically, the X-axis transmission assembly 23 is disposed between the first movable platform 21 and the second movable platform 22 , and includes a pair of X-axis guide rails 24 . The X-axis transmission assembly 23 can drive the first movable platform 21 to move along the X-axis guide rails 24 .

[0029] Specifically, the Y-axis transmission assembly 25 is disposed between the second movable platform 22 and the base 1, and includes a pair of Y-axis guide rails 26. The Y-axis guide rails 26 are perpendicular to the X-axis guide rails 24. The Y-axis transmission assembly 25 can drive the second movable platform 22 to move along the Y-axis guide rails 26.

[0030] The loading platform 3 is provided on the surface of the first moving platform 21. Specifically, the loading platform 3 is made of a transparent material, such as glass, plastic, etc. The loading platform 3 is used to place the object to be measured and can serve as a zero reference in the Z direction.

[0031] The loading platform 3 can move along the X-axis and Y-axis along with the XY motion platform 2 .

[0032] The column 8 is fixed to the base 1 , and the column 8 extends along the Z-axis direction, which is perpendicular to the plane where the loading platform 3 is located.

[0033] The optical imaging assembly 4 is used for optical photography to obtain an image of the object to be measured. The optical imaging assembly 4 includes an optical microscope tube 41 , a CCD 42 , a light source 43 , and a bracket 44 .

[0034] The optical microscope tube 41 is used to magnify and focus the object to be measured.

[0035] The CCD 42 scans the object under test and outputs a digital image signal. The CCD 42 includes a signal output interface 421. The CCD 42 can be connected to a computer via the signal output interface 421. The computer is loaded with measurement software that can process and analyze the digital image signal accordingly.

[0036] The light source 43 includes a light panel 431 provided with a plurality of light bulbs and a light shield 432 . The light source 43 is located above the object loading platform 3 and is used to illuminate the surface of the object to be measured on the object loading platform 3 .

[0037] Specifically, the CCD 42 is fixed to the upper end of the optical microscope tube 41 , and the light source 43 is fixed to the lower end of the optical microscope tube 41 .

[0038] The bracket 44 includes a first fixing portion 441 fixed to the Z-axis lifting module 5 , a second fixing portion 442 for clamping the optical microscope tube 41 , and a third fixing portion 443 .

[0039] The Z-axis lifting module 5 is assembled on the column 8 . The Z-axis lifting module 5 includes a Z-axis transmission component 51 and a Z-axis guide rail 52 . The Z-axis transmission component 51 can drive the optical imaging component 4 to move along the Z-axis guide rail 52 , thereby achieving focusing of the optical imaging component 4 .

[0040] The counting grating ruler 6 is fixed to the Z-axis lifting module 5 and is used to output the absolute coordinate position information in the Z direction in real time. The absolute coordinate position information collected by the counting grating ruler 6 is transmitted to the computer, and the measurement software can perform corresponding data analysis on the absolute coordinate position information.

[0041] The outer cover 7 surrounds the optical imaging assembly 4 and provides dust protection.

[0042] During testing, if you want to use multiple fully automatic imagers to measure the same product at the same time, under ideal conditions, the theoretical coordinate system zero point Z of each fully automatic imager is the same, and the theoretical focusing height Z0 = Z + C of the optical microscope tube is also the same.

[0043] However, in actual manufacturing, due to processing and assembly errors, the actual upward movement distance of the focus height Zn of each fully automatic imager is Cn. In special cases, Cn≠C. As a result, if multiple fully automatic imagers are used to measure the same product simultaneously, the measurement software needs to be reprogrammed and debugged, resulting in a waste of time and manpower.

[0044] Please refer to Figure 5 As shown, the present invention provides a Z-axis zero position calibration method for a fully automatic imager 100, which includes the following steps:

[0045] S1, setting the upper surface of the object-carrying platform as the theoretical coordinate system zero point Z, the theoretical focusing height of the optical microscope barrel as Z0, and the distance between the theoretical coordinate system zero point Z and the theoretical focusing height Z0 as C (C is a constant);

[0046] S2, after the fully automatic imager is powered on and initialized, the measurement software is opened and the "one-key return to zero" function is clicked. The Z-axis lifting module drives the optical imaging component to automatically scan and search the upper surface of the loading platform within the upper and lower areas of the theoretical focusing height Z0 and take a number of pictures. The counting grating ruler collects the Z-axis absolute coordinate values ​​of the several pictures;

[0047] S3, the measurement software analyzes the clearest one of the multiple images, obtains the corresponding actual focus height Zn, and calculates the distance between the theoretical coordinate system zero point Z and the actual focus height Zn as Cn;

[0048] S4. The measurement software controls the Z-axis lifting module to shift along the Z-axis at the current actual focusing height Zn position by -△C=Cn-C, thereby correcting the theoretical coordinate system zero point of the Z-axis.

[0049] like Figure 6 As shown, in another embodiment, in step S3, the measurement software analyzes the several pictures, extracts the clearest pictures, and makes the pictures overlap in the height direction to form a height area. In the height area, the measurement software fits a peak point in a parabolic manner according to the clarity of each picture. The Z-axis coordinate value corresponding to the peak point is the actual focusing height Zn, and the distance between the zero point Z of the theoretical coordinate system and the actual focusing height Zn is calculated to be Cn.

[0050] Specifically, in step S2, a smooth search scan is performed on the upper surface of the loading platform 3 at fixed intervals in the upper and lower areas of the theoretical focusing height Z0 position to obtain a number of pictures, each of which has absolute coordinate value information fed back from the counting grating ruler 16. The computer measurement software uses an algorithm to quickly analyze the clearest picture in real time and calculate the corresponding actual focusing height Zn.

[0051] Specifically, the fixed interval is 0.1 micrometer, but is not limited thereto.

[0052] The present invention also provides a measuring system, which adopts the Z-axis zeroing position calibration method of the fully automatic imager.

[0053] In summary, the Z-axis zero position calibration method and measurement system of the fully automatic imager of the present invention effectively solves the problem of inconsistent zero points of the Z-axis theoretical coordinate systems of multiple fully automatic imagers, which is beneficial for large-scale testing without the need to reprogram and debug each fully automatic imager, reducing manpower and time costs and improving test efficiency.

[0054] Finally, it should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for calibrating the Z-axis zero position of a fully automatic imager, wherein the fully automatic imager comprises a loading platform, an optical imaging assembly located above the loading platform, a Z-axis lifting module capable of driving the optical imaging assembly to move along the Z-axis, and a counting grating ruler capable of outputting Z-axis absolute coordinate values. The optical imaging assembly comprises an optical microscope tube, a CCD mechanism, and a light source, wherein: The method comprises the steps of: S1, setting the upper surface of the object-carrying platform as the theoretical coordinate system zero point Z, the theoretical focusing height of the optical microscope tube as Z0, and the distance between the theoretical coordinate system zero point Z and the theoretical focusing height Z0 as C, where C is a constant; S2, after the fully automatic imager is powered on and initialized, the measurement software is opened and the "one-key return to zero" function is clicked. The Z-axis lifting module drives the optical imaging component to automatically scan and search the upper surface of the loading platform within the upper and lower areas of the theoretical focusing height Z0 and take a number of pictures. The counting grating ruler collects the Z-axis absolute coordinate values ​​of the several pictures, and each picture has a corresponding Z-axis coordinate value information; In step S2, the optical imaging component smoothly scans the upper surface of the object carrier platform at a fixed interval above and below the theoretical focus height Z0, where the fixed interval is 0.1 micrometers. S3, the measurement software analyzes the plurality of images, extracts the clearest one, obtains the corresponding actual focus height Zn, and calculates the distance Cn between the theoretical coordinate system zero point Z and the actual focus height Zn; In step S3, the measurement software analyzes the plurality of images, extracts the clearest images, and spatially overlaps the images in the height direction to form a height region. Within the height region, the measurement software then uses a parabola to fit a peak point based on the clarity of each image. The Z-axis coordinate value corresponding to the peak point is the actual focusing height Zn. S4. The measurement software controls the Z-axis lifting module to shift along the Z-axis at the current actual focus height Zn by -ΔC=Cn-C, thereby correcting the theoretical coordinate system zero point Z of the Z-axis.

2. The Z-axis zeroing calibration method of a fully automatic imaging device according to claim 1, characterized in that: The CCD mechanism is fixed to the upper end of the optical microscope tube, the light source is fixed to the lower end of the optical microscope tube, and the light source is located above the object carrying platform.

3. The Z-axis zeroing calibration method of a fully automatic imaging device according to claim 2, characterized in that: The Z-axis lifting module includes a Z-axis transmission assembly and a Z-axis guide rail, and the counting grating ruler is fixed to the Z-axis lifting module.

4. The Z-axis zeroing calibration method of a fully automatic imaging device according to claim 3, characterized in that: The fully automatic imager also includes a base and an XY motion platform arranged on the base. The XY motion platform includes a first moving platform located on the upper layer, a second moving platform located on the middle layer, an X-axis transmission assembly, an X-axis guide rail, a Y-axis transmission assembly and a Y-axis guide rail.

5. The Z-axis zeroing calibration method of a fully automatic imaging device according to claim 4, characterized in that: The X-axis transmission assembly is arranged between the first moving platform and the second moving platform, and the Y-axis transmission assembly is arranged between the second moving platform and the base.

6. The Z-axis zeroing calibration method of a fully automatic imaging device according to claim 5, characterized in that: The optical imaging assembly further includes a bracket, and the bracket includes a first fixing portion fixed to the Z-axis lifting module, a second fixing portion clamping the optical microscope barrel, and a third fixing portion.

7. The Z-axis zeroing calibration method of a fully automatic imaging device according to claim 6, characterized in that: The light source includes a light panel provided with a plurality of light bulbs and a light cover.

8. A measuring system, comprising the Z-axis zeroing calibration method of a fully automatic imager according to any one of claims 1 to 7.

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