A non-contact high-precision measurement method and device for measuring the Z-axis direction of an object under microscopic conditions

Abstract

The present invention discloses a non-contact high-precision measurement method and a measuring device for the Z-axis direction of an object under microscopic conditions, and the measuring method includes: step 1: placing a standard gauge block on a loading platform, so that the top surface of the standard gauge block coincides with the focus of an optical lens, and at this time, the degree of a photoelectric distance sensor is cleared for the first time; step 2: adjusting the thickness of the standard gauge block when the loading platform rises, and at this time, the degree of the photoelectric distance sensor is cleared for the second time; step 3: the focus of the optical lens coincides with the zero point of the photoelectric distance sensor; step 4: making the top surface of the object to be measured on the loading platform coincide with the focus of the optical lens, and reading the degree of the photoelectric distance sensor to obtain the absolute value of the thickness of the object to be measured in the Z-axis direction. The present invention can detect the absolute value of the thickness of an object in the Z-axis direction in a narrow space, and its accuracy can reach the microscopic nanometer level, and the detection efficiency and detection accuracy are significantly better than the prior art.

Description

Technical Field

[0001] The present invention relates to the field of optical measurement technology, in particular to a non-contact high-precision measurement method and a measuring device for the Z-axis direction of an object under microscopic conditions. Background Art

[0002] With the development of science and technology, microscopic vision measurement has been widely used. Among microscopic vision measurement devices, there is no unified standard measurement device in the world. There are many different forms of measurement devices. Different measurement devices are developed and used due to different measurement objects. At the same time, in the field of machine vision measurement, more mature experimental instruments and equipment are mainly suitable for the measurement and research of macroscopic objects. However, most of the objects involved in microscopic vision measurement are smaller than the measurement probe itself in the existing technology. For example, in the narrow position such as the depth of the groove of the pull ring of the can, the detection probe cannot be inserted into the groove, so it is difficult to detect.

[0003] In the prior art, the Z-axis value of an object is mostly measured using a three-coordinate detection system. The principle is to focus a laser probe on the upper surface of the object, use this point as the zero point, find another point as the reference point, and read the displacement difference between the two through a sensor. However, since the width of the narrow gap exceeds the diameter of the laser target point of the three-coordinate detection system in the prior art, this method cannot detect the absolute value of the thickness of the lowest point of the object's slit. It can only detect the height difference between two points on the upper surface of the object, and obtain the thickness value of the lowest point by subtracting the total thickness of the object. However, there is a certain positioning error and human detection error between the bottom surface of the object and the plane workbench of the three-axis coordinate system. Under microscopic and nanoscopic conditions, the error will be magnified many times, making it difficult to meet the detection accuracy requirements.

[0004] After searching, the following patents were found:

[0005] CN214201158U discloses a system and method for three-dimensional microscopic imaging of the entire surface of a sample, and relates to the technical field of medical sample detection instruments. The system uses a sample morphology measurement module to map the surface morphology of the sample to be tested, establish a three-dimensional model, grid the three-dimensional model, obtain the center coordinates and normal vector of each grid unit, and generate a mechanical scanning command, and uses an omnidirectional three-dimensional mechanical scanning module to move the microscopic imaging module in a fixed-point normal direction, so that it can perform microscopic imaging of the sample surface at different heights in each grid unit. The three-dimensional image reconstruction algorithm generates a microscopic image of the entire surface of the sample by connecting the clear images in all focal planes. The image evaluation and feedback system uses machine learning to evaluate high-risk or specific areas on the sample surface, and the user decides to perform more accurate microscopic imaging of the local area. The sample adsorption module includes an adsorption mechanism and a rotation mechanism to achieve the fixation and flipping of the sample to be tested.

[0006] After analysis, the above-mentioned patent still fails to solve the problem of measuring the Z-axis thickness value of an object in a narrow space, and there are significant differences between the measurement device structure and the measurement method and the present application, so it does not affect the novelty of the present application. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a non-contact high-precision measurement method and a measuring device for the Z-axis direction of an object under microscopic conditions. The measuring device and the measuring method can detect the absolute value of the thickness of an object in the Z-axis direction in a small space with an accuracy of up to the microscopic nanometer level. Only one standard gauge block auxiliary calibration and zeroing is required to perform multiple measurements of objects of different thicknesses. The detection efficiency and detection accuracy are significantly better than those of the prior art.

[0008] A non-contact high-precision measurement method for the Z-axis direction of an object under microscopic conditions comprises the following steps:

[0009] Step 1: First, place the standard gauge block horizontally on the detection hole of the stage, ensure that the top surface of the standard gauge block is illuminated by the optical lens, and the bottom surface of the standard gauge block is illuminated by the photoelectric distance sensor, and then raise and lower the stage to make the focus of the best image collected by the optical lens coincide with the top surface of the standard gauge block; the coincidence positioning information of the focus and the top surface of the standard gauge block is collected by the photoelectric measurement system through the optical lens image, and finally calculated and determined; at this time, the reading of the photoelectric distance sensor is cleared;

[0010] Step 2: Adjust the load platform to rise. The starting point of the load platform rising action is the zero point of the photoelectric distance sensor after being cleared in step 1, and the rising value of the entire load platform is the known thickness value of the standard gauge block, and ensure that the known thickness value is consistent with the reading on the photoelectric distance sensor; then clear the reading of the photoelectric distance sensor again;

[0011] Step 3: Calibrate the measuring device through steps 1 and 2, so that the focus of the optical lens coincides with the zero point of the photoelectric distance sensor;

[0012] Step 4: Take the standard gauge block on the stage, place the object to be measured on the detection hole of the stage, and then adjust the height of the stage so that the top surface of the object to be measured coincides with the focus of the optical lens. At this time, read the reading on the photoelectric distance sensor to get the absolute value of the thickness of the object to be measured in the Z-axis direction.

[0013] A measuring device adopted in a non-contact high-precision measurement method of an object in the Z-axis direction under microscopic conditions comprises a microscope support, the lower part of the microscope support is vertically limited and horizontally adjusted and connected to a sensor platform, the middle part of the microscope support is lifted and adjusted and connected to an object-carrying platform, an optical lens is vertically fixedly arranged on the top of the microscope support; a photoelectric distance-measuring sensor is fixedly arranged on the top surface of the sensor platform; a detection hole is vertically penetrated and formed in the middle part of the object-carrying platform; the optical lens, the photoelectric distance-measuring sensor and the detection hole are coaxially arranged.

[0014] Moreover, a lifting block is connected to the lifting adjustment of the middle part of the microscope support, and one side of the lifting block is fixedly connected to the object-carrying platform through a supporting plate.

[0015] Moreover, the measuring device is connected to a photoelectric measuring system, which collects and calculates the focal length information of the optical lens and the reading of the photoelectric ranging sensor, and obtains the thickness value of the object in the Z-axis direction under microscopic conditions through the difference between the two readings of the photoelectric ranging sensor.

[0016] The advantages and technical effects of the present invention are:

[0017] The invention discloses a non-contact high-precision measuring device for measuring the Z-axis direction of an object under microscopic conditions. The main body is supported by a microscope support. The object-carrying platform in the middle of the microscope support and the sensor platform at the bottom of the limit support are used to ensure that the axes of the focus of the optical lens, the thickness measurement point of the object to be measured and the photoelectric distance measuring sensor coincide with each other, so as to complete the positioning of the device before measurement. Finally, the lifting block is used as a moving part adjusted during the measurement process to drive the support plate and the object-carrying platform to lift and slide, so as to facilitate finding the focus of the optical lens with the top surface of the object to be measured and reading the optical distance measuring sensor with the bottom surface of the object to be measured.

[0018] The invention discloses a measuring method adopted by a non-contact high-precision measuring device for measuring the Z-axis direction of an object under microscopic conditions. The optical lens and the photoelectric distance measuring sensor with a constant spacing are used to illuminate the top surface and the bottom surface of the object to be measured oppositely, and the height of the object-carrying platform is adjusted to make the top surface of the object to be measured coincide with the focus of the optical lens. At this time, it is necessary to ensure that the focus of the optical lens coincides with the zero point of the photoelectric distance measuring sensor, and then the reading of the photoelectric distance measuring sensor is read to obtain the absolute value of the thickness of the object to be measured in the Z-axis direction.

[0019] The invention discloses a non-contact high-precision measurement method and a measuring device for measuring the Z-axis direction of an object under microscopic conditions. The method adopts an upper optical lens for focusing and a lower photoelectric distance measuring sensor for distance measuring. The two synchronize their focus to control the displacement of the object and detect the microscopic Z-axis. Because the invention only performs detection and observation by the upper optical system and direct reading by the lower photoelectric distance measuring sensor, and only needs to perform auxiliary calibration and zeroing of a standard gauge block once, the measurement of objects of different thicknesses can be performed multiple times, and there is no need to perform detection and observation by the upper and lower parts respectively, and there is no need to perform repeated calibration every time a new object is detected, so the detection efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view of the present invention;

[0021] In the figure: 1-optical lens; 2-microscope support; 3-object carrier platform; 4-support plate; 5-lifting block; 6-sensor platform. DETAILED DESCRIPTION

[0022] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings. It should be noted that the embodiments are illustrative, not restrictive, and the protection scope of the present invention cannot be limited thereby.

[0023] A non-contact high-precision measurement method for the Z-axis direction of an object under microscopic conditions comprises the following steps:

[0024] Step 1: First, place the standard gauge block horizontally on the detection hole of the stage, ensure that the top surface of the standard gauge block is illuminated by the optical lens, and the bottom surface of the standard gauge block is illuminated by the photoelectric distance sensor, and then raise and lower the stage to make the focus of the best image collected by the optical lens coincide with the top surface of the standard gauge block; the coincidence positioning information of the focus and the top surface of the standard gauge block is collected by the photoelectric measurement system through the optical lens image, and finally calculated and determined; at this time, the reading of the photoelectric distance sensor is cleared;

[0025] Step 2: Adjust the load platform to rise. The starting point of the load platform rising action is the zero point of the photoelectric distance sensor after being cleared in step 1, and the rising value of the entire load platform is the known thickness value of the standard gauge block, and ensure that the known thickness value is consistent with the reading on the photoelectric distance sensor; then clear the reading of the photoelectric distance sensor again;

[0026] Step 3: Calibrate the measuring device through steps 1 and 2, so that the focus of the optical lens coincides with the zero point of the photoelectric distance sensor;

[0027] Step 4: Take the standard gauge block on the stage, place the object to be measured on the detection hole of the stage, and then adjust the height of the stage so that the top surface of the object to be measured coincides with the focus of the optical lens. At this time, read the reading on the photoelectric distance sensor to get the absolute value of the thickness of the object to be measured in the Z-axis direction.

[0028] A measuring device for a non-contact high-precision measurement method of an object in the Z-axis direction under microscopic conditions comprises a microscope support 2, the lower part of which is vertically limited and horizontally adjusted and connected to a sensor platform 6, the middle part of which is lifted and lowered and adjusted and connected to an object platform 3, an optical lens 1 is vertically fixedly arranged on the top of the microscope support; a photoelectric distance sensor is fixedly arranged on the top surface of the sensor platform; a detection hole is vertically penetrated and formed in the middle part of the object platform; the optical lens, the photoelectric distance sensor and the detection hole are coaxially arranged.

[0029] Moreover, a lifting block 5 is connected to the middle part of the microscope support for lifting adjustment, and one side of the lifting block is fixedly connected to the object stage through a supporting plate 4.

[0030] Moreover, the measuring device is connected to a photoelectric measuring system, which collects and calculates the focal length information of the optical lens and the reading of the photoelectric ranging sensor, and obtains the thickness value of the object in the Z-axis direction under microscopic conditions through the difference between the two readings of the photoelectric ranging sensor.

[0031] In addition, in the present invention, preferably, the optical lens, the microscope support, the object-carrying platform, the sensor platform and the photoelectric distance measuring sensor are all mature products in the prior art.

[0032] In addition, the present invention preferably uses a mature product from the existing technology center for the photoelectric measurement system, and the calculation software carried therein and the focal length information of the optical lens obtained by the software algorithm all use mature technical means in the existing technology.

[0033] In order to more clearly illustrate the specific implementation mode of the present invention, an embodiment is provided below:

[0034] The present invention discloses a non-contact high-precision measurement method and a measuring device for measuring the Z-axis direction of an object under microscopic conditions, which are particularly suitable for measuring the absolute value of the thickness of an object at the bottom of a narrow gap in the Z-axis direction. Before measurement, it is necessary to ensure that the axes of the optical lens, the thickness measurement point of the object to be measured, and the photoelectric distance sensor coincide with each other; then the measuring device is calibrated, and the photoelectric distance sensor needs to be cleared twice during the calibration process:

[0035] 1. The first zeroing can ensure that the rising height of the stage is consistent with the thickness value of the standard gauge block; because the lifting and sliding connection between the lifting block and the microscope support is not a high-precision connection, threaded screws or stepper motors are mostly used in the prior art, but their accuracy is poor and cannot meet the accuracy requirements of nano-level optical microscopy ranging. Therefore, in order to improve the measurement accuracy while ensuring the measurement efficiency, there is no need for a high-precision connection between the lifting block and the microscope support. The zero point of the photoelectric ranging sensor before step 2 can be obtained through the first zeroing and the known thickness of the standard gauge block. When the bottom surface of the standard gauge block is at the zero point position, the top surface of the standard gauge block coincides with the focus of the optical lens.

[0036] 2. The second zeroing can ensure that the focus of the optical lens coincides with the zero point of the photoelectric distance sensor; the second zeroing point of the photoelectric distance sensor is finally obtained by combining the starting point of the load platform rise obtained in step 1, the known thickness of the standard gauge block and the reading of the photoelectric distance sensor. At this time, the focus of the optical lens, the zero point of the photoelectric distance sensor and the bottom surface of the standard gauge block coincide. Finally, remove the standard gauge block and place the object to be measured. The bottom surface of the object to be measured will replace the bottom surface of the standard gauge block and coincide with the focus of the optical lens and the zero point of the photoelectric distance sensor. Then control the load platform to descend until the top surface of the object to be measured coincides with the focus of the optical lens. At this time, read the reading on the photoelectric distance sensor to obtain the absolute value of the thickness of the detection point of the object to be measured in the Z-axis direction.

[0037] It should be noted that the advantage of the present invention also lies in its high precision. In the three-coordinate detection system of the prior art, the diameter of the laser target point is relatively large, and it is impossible to detect the absolute value of the bottom thickness of the narrow gap. However, the present application can adjust the magnification of the image collected by the optical lens so that the center focus of the image is aligned with the top surface of the bottom of the narrow gap of the object to be measured. As the image magnification increases, the measurement accuracy of the present invention will also increase exponentially. It only needs to adopt the calibration method in the measurement method of the present invention to make the focus of the optical lens coincide with the zero point of the photoelectric ranging sensor to ensure that the measurement error is controlled within the allowable range.

[0038] Finally, all the parts not described in the present invention adopt mature products and mature technical means in the prior art.

[0039] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A non-contact high-precision measurement method for the Z-axis direction of an object under microscopic conditions, characterized in that: The following steps are involved: Step 1: First, place the standard gauge block horizontally on the detection hole of the stage, ensure that the top surface of the standard gauge block is illuminated by the optical lens, and the bottom surface of the standard gauge block is illuminated by the photoelectric distance sensor, and then raise and lower the stage to make the focus of the best image collected by the optical lens coincide with the top surface of the standard gauge block; the coincidence positioning information of the focus and the top surface of the standard gauge block is collected by the photoelectric measurement system through the optical lens image, and finally calculated and determined; at this time, the reading of the photoelectric distance sensor is cleared; Step 2: Adjust the load platform to rise. The starting point of the load platform rising action is the zero point of the photoelectric distance sensor after being cleared in step 1, and the rising value of the entire load platform is the known thickness value of the standard gauge block, and ensure that the known thickness value is consistent with the reading on the photoelectric distance sensor; then clear the reading of the photoelectric distance sensor again; Step 3: Calibrate the measuring device through steps 1 and 2, so that the focus of the optical lens coincides with the zero point of the photoelectric distance sensor; Step 4: Take the standard gauge block on the loading platform, and place the object to be measured on the detection hole of the loading platform, and then adjust the height of the loading platform so that the top surface of the object to be measured coincides with the focus of the optical lens. At this time, read the reading on the photoelectric distance sensor to obtain the absolute value of the thickness of the object to be measured in the Z-axis direction; The measuring device used in the measuring method comprises a microscope support, the lower part of which is vertically limited and horizontally adjusted and connected to a sensor platform, the middle part of which is lifted and lowered and adjusted and connected to an object-carrying platform, an optical lens is vertically fixedly arranged on the top of the microscope support; a photoelectric distance-measuring sensor is fixedly arranged on the top surface of the sensor platform; a detection hole is vertically penetrated and formed in the middle part of the object-carrying platform; the optical lens, the photoelectric distance-measuring sensor and the detection hole are coaxially arranged.

2. The non-contact high-precision measurement method of an object in the Z-axis direction under microscopic conditions according to claim 1, characterized in that: The middle part of the microscope support is connected to a lifting block for lifting adjustment, and one side of the lifting block is fixedly connected to the object-carrying platform through a supporting plate.

3. The non-contact high-precision measurement method of an object in the Z-axis direction under microscopic conditions according to claim 1, characterized in that: The measuring device is connected to a photoelectric measuring system, which collects and calculates the focal length information of the optical lens and the reading of the photoelectric distance sensor, and obtains the thickness value of the object in the Z-axis direction under microscopic conditions through the difference between the two readings of the photoelectric distance sensor.

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