Method for measuring thickness of transparent flat plate through non-contact method

Abstract

The invention relates to the technical field of transparent flat plate thickness measurement, and discloses a method for measuring the thickness of a transparent flat plate by a non-contact method, which comprises the following steps of: building a measurement light path: electrifying a light source, and enabling light of the light source to pass through a collecting lens, a reticle, a beam splitter prism and an objective lens group in sequence and then pass through a lower wedge-shaped lens and an upper wedge-shaped lens to be converged on an optical plane of the transparent flat plate; light adjustment: adjusting a light path, enabling the normal of the transparent flat optical plane to be parallel to the light path, ensuring that the reflected light of the transparent flat optical plane and the normal of the incident light return symmetrically, changing the direction of the light path through the reflection of the beam splitter prism, and imaging on the CCD camera on the split image focusing screen through the split image. Light passing through the light source is changed into parallel light through the collecting lens to be irradiated on the reticle, light of scribed lines of the reticle is converged through the objective lens set, the light path direction is changed through reflection of the beam splitter prism, the light is imaged on the CCD through the lens set, and the method is simple in configuration and convenient to operate under the condition that the transparent flat plate is measured without damage.

Description

Technical Field

[0001] The invention relates to the technical field of measuring the thickness of a transparent flat plate, in particular to a method for measuring the thickness of a transparent flat plate using a non-contact method. Background Art

[0002] In modern industrial production and scientific research, transparent flat sheet materials are widely used in fields such as optics, electronics, and architecture. Their thickness, as a key parameter, plays a decisive role in product performance and quality. Traditional contact measurement methods, such as the use of tools like micrometers and vernier calipers, are not only inflexible and inefficient, but also easily leave scratches on the surface of transparent flat sheets, affecting product quality. They are no longer able to meet today's high-precision, high-efficiency production and testing needs. Therefore, non-contact measurement methods have emerged and are rapidly developing.

[0003] However, traditional non-contact measurement methods require adjusting the collimation of light like an autocollimator, so the optical path adjustment is more troublesome. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for measuring the thickness of a transparent flat plate using a non-contact method, which solves the problem of troublesome optical path adjustment.

[0005] To achieve the above object, the present invention is implemented by the following technical solution: A method for measuring the thickness of a transparent plate by a non-contact method comprises the following steps:

[0006] Build the measurement optical path: Power on the light source so that the light from the light source passes through the condenser, graticule, beam splitter, objective lens group in sequence, and then converges to the optical plane of the transparent plate through the lower wedge mirror and the upper wedge mirror;

[0007] Light adjustment: adjust the light path so that the normal line of the transparent flat optical plane is parallel to the light path, ensuring that the reflected light from the transparent flat optical plane is returned symmetrically with the normal line of the incident light, changes the direction of the light path through the beam splitter prism, passes through the split image on the split image focusing screen and forms an image on the CCD camera;

[0008] Measurement operation: Start the motor to drive the threaded column to rotate, which drives the threaded block and the second connecting plate to move, so that the upper wedge mirror is adjusted along the direction of the lower wedge mirror, so that the light is converged on the front and back surfaces of the transparent plate respectively. The convergence alignment standard is that the upper and lower split images on the split-image focusing screen overlap.

[0009] Preferably, it is characterized in that the upper wedge-shaped mirror and the lower wedge-shaped mirror are made of the same material and have the same angle, and the opposite surfaces of the upper wedge-shaped mirror and the lower wedge-shaped mirror are perpendicular to the optical path.

[0010] Preferably, the calculation formula for the thickness of the transparent plate is as follows: t = (n0-1) × L × θ / n1, where t is the thickness of the transparent plate, n0 is the refractive index of the material of the upper wedge mirror and the lower wedge mirror, θ is the wedge angle of the upper wedge mirror and the lower wedge mirror, in radians, n0 is the refractive index of the transparent plate material, and L is the distance the upper wedge mirror moves.

[0011] Preferably, a device for measuring the thickness of a transparent flat plate using a non-contact method comprises a shell, a light source is provided at the middle position of the inner wall of the shell, a fixing plate 1 is fixedly connected to the interior of the shell, a condenser is provided on the inner wall of the fixing plate 1, a fixing plate 2 is fixedly connected to the inner wall of the shell, a graticule is provided on the inner wall of the fixing plate 2, a connecting frame is fixedly connected to the interior of the shell, a dichroic prism is provided on the inner wall of the connecting frame, a fixing plate 3 is fixedly connected to the inner wall of the shell, an objective lens group is provided on the inner wall of the fixing plate 3, baffles are fixedly connected to both sides of the inner wall of the shell, a block is slidably connected to the inner wall of the baffle, a lower wedge mirror is fixedly connected to the outer wall of the block, The outer wall of the lower wedge-shaped mirror is fixedly connected to a connecting plate 1, the inner wall of the connecting plate 1 is provided with a bolt 1, the inner wall of the outer shell is provided with a motor, the output end of the motor is provided with a threaded column, the outer wall of the threaded column is threadedly connected to a threaded block, the upper surface of the threaded block is fitted with a connecting plate 2, the inner wall of the connecting plate 2 is provided with a bolt 2, the outer wall of the bolt 2 is provided with a slider, the outer wall of the bolt 2 is fixedly connected to the upper wedge-shaped mirror, the inner wall of the outer shell is fixedly connected to a support frame, the upper surface of the support frame is fitted with a transparent flat plate, a split-image focusing screen is provided inside the outer shell, a CCD camera is provided on the inner wall of the outer shell, and the split-image focusing screen is located directly in front of the CCD camera.

[0012] Preferably, the condenser is located directly above the light source, the graticule is located directly above the condenser, the beam splitter prism is located directly above the graticule, and the objective lens group is located directly above the beam splitter prism.

[0013] Preferably, the inclination angle of the threaded column is the same as the angle of the wedge surface of the lower wedge-shaped mirror, and the outer wall of the threaded block is slidably connected to the inner wall of the shell.

[0014] Preferably, the outer wall of the slider is slidably connected to the inner wall of the shell, and the outer wall of the second connecting plate is in contact with the outer wall of the slider.

[0015] Preferably, the outer wall of the bolt 1 is arranged on the inner wall of the baffle, and the outer wall of the connecting plate 1 is attached to the outer wall of the baffle.

[0016] Preferably, when the upper wedge-shaped mirror moves, it always moves parallel to the wedge surface of the lower wedge-shaped mirror, and the distance between the upper wedge-shaped mirror and the lower wedge-shaped mirror remains unchanged.

[0017] Preferably, the split-image focusing screen is used to judge the alignment degree of light converging on the surface of the transparent flat plate, and whether the light is accurately converging on the front and back surfaces of the transparent flat plate is determined by observing the overlap of the upper and lower split images on the split-image focusing screen.

[0018] The present invention provides a non-contact method for measuring the thickness of a transparent plate. It has the following beneficial effects:

[0019] 1. The present invention converts light from a light source into parallel light through a condenser and illuminates a graticule. The light from the lines of the graticule is converged by an objective lens group. The reflected light from the optical plane is symmetrical with the normal line of the incident light and returns to the optical system. The light path direction is changed by reflection from a beam splitter prism and the image is formed on a CCD through a lens group. This method achieves the purpose of non-destructive measurement of a transparent flat plate. The configuration is simple and the operation is convenient.

[0020] 2. The present invention starts the motor to drive the threaded column to rotate, and the rotation of the threaded column drives the threaded block to move, and then drives the connecting plate and the upper wedge mirror to move, thereby realizing the focus of light on the front and rear surfaces of the transparent plate respectively, achieving the purpose of simple adjustment of the upper wedge mirror and low overall cost.

[0021] 3. The present invention unscrews and removes bolts 1 and 2, then takes out the upper wedge mirror and the lower wedge mirror, replaces the required upper wedge mirror and lower wedge mirror, and then fixes the two with bolts 1 and 2, thereby achieving the goal of replacing the upper wedge mirror and the lower wedge mirror according to the thickness and tolerance accuracy of the transparent plate, thereby improving the applicability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A perspective view of the present invention;

[0023] Figure 2 It is a schematic cross-sectional view of the internal structure of the housing of the present invention;

[0024] Figure 3 It is a partial structural diagram of a fixing plate of the present invention;

[0025] Figure 4 It is a schematic diagram of the local structure of the motor of the present invention;

[0026] Figure 5 Schematic diagram of the light propagation path of the present invention;

[0027] Figure 6 Schematic diagram of the movement path of the upper wedge mirror of the present invention;

[0028] Figure 7 A schematic diagram of presenting a split image on a CCD camera according to the present invention;

[0029] Figure 8 Schematic diagram of the method of the present invention.

[0030] Among them, 1. Outer shell; 2. Light source; 3. Fixing plate 1; 4. Condenser; 5. Fixing plate 2; 6. Graticule; 7. Connecting frame; 8. Beam splitter prism; 9. Fixing plate 3; 10. Objective lens group; 11. Lower wedge mirror; 12. Connecting plate 1; 13. Bolt 1; 14. Stop block; 15. Slider; 16. Motor; 17. Threaded column; 18. Threaded block; 19. Connecting plate 2; 20. Bolt 2; 21. Upper wedge mirror; 22. Support frame; 23. Transparent plate; 24. Split-image focusing screen; 25. CCD camera; 26. Baffle. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all 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] Please see the attached Figure 1 -Attached Figure 7 The embodiment of the present invention provides a method for measuring the thickness of a transparent plate using a non-contact method, comprising the following steps:

[0033] Build the measurement optical path: Power on the light source 2 so that the light from the light source 2 passes through the condenser 4, the graticule 6, the beam splitter 8, the objective lens group 10, and then converges onto the optical plane of the transparent plate 23 through the lower wedge mirror 11 and the upper wedge mirror 21;

[0034] Light adjustment: Adjust the light path so that the normal line of the optical plane of the transparent plate 23 is parallel to the light path, ensuring that the reflected light from the optical plane of the transparent plate 23 is returned symmetrically with the normal line of the incident light, and is reflected by the beam splitter prism 8 to change the direction of the light path, pass through the split image on the split-image focusing screen 24, and form an image on the CCD camera 25;

[0035] Measurement operation: Start the motor 16 to drive the threaded column 17 to rotate, which drives the threaded block 18 and the connecting plate 2 19 to move, so that the upper wedge mirror 21 is adjusted along the direction of the lower wedge mirror 11, so that the light is respectively converged on the front and rear surfaces of the transparent flat plate 23, and the convergence alignment standard is that the upper and lower split images on the split-image focusing screen 24 overlap.

[0036] Specifically, at the beginning of the measurement, the light source 2 emits light, which serves to provide an illumination basis for the entire measurement. The light is converged by the condenser 4. The function of the condenser 4 is to convert the divergent light into parallel light to ensure that the light propagates evenly and stably. The parallel light is irradiated on the graticule 6. The light of the lines on the graticule 6 carries identification features, which are used to subsequently judge the light state. The light then passes through the beam splitter prism 8, which reflects the light to the objective lens group 10 and changes the direction of the light when the light is reflected back to ensure the continuity of the light path. The objective lens group 10 converges the light so that it can be subsequently focused on the optical plane of the transparent plate 23. The converged light then passes through the upper wedge mirror 21 and the lower wedge mirror 11. By starting the motor 16, the upper wedge mirror 21 is driven to change by translation. The optical path causes light to converge on the front and rear surfaces of the transparent plate 23, respectively, for measuring the thickness of the transparent plate 23. The light reaches the optical plane of the transparent plate 23, which serves as the measurement object. The reflected light is redirected by the beam splitter prism 8 and then passes through the split-image focusing screen 24. The split-image focusing screen 24 is used to assist in determining the degree of alignment of the light converged on the surface of the transparent plate 23, thereby improving measurement accuracy. Finally, the light is imaged on the CCD camera 25, which converts the optical signal into an electrical signal for imaging, so as to analyze and calculate the thickness of the transparent plate 23. Compared with the traditional contact measurement method that causes damage to the surface of the transparent plate 23, this method can achieve non-destructive measurement of the transparent plate 23. The configuration of the method is simple and the operation is convenient.

[0037] Please see the attached Figure 1 -Attached Figure 7 The upper wedge mirror 21 and the lower wedge mirror 11 have the same material and angle, and the opposite surfaces of the upper wedge mirror 21 and the lower wedge mirror 11 are perpendicular to the optical path.

[0038] Specifically, the upper wedge mirror 21 and the lower wedge mirror 11 are made of the same material and angle, and the opposite surfaces are perpendicular to the optical path. The deflection of light passing through the lower wedge mirror 11 is offset by the reverse deflection of the lower wedge mirror 11, so that the angle of the outgoing light remains unchanged. Compared with the traditional method of only setting up one upper wedge mirror 21 or lower wedge mirror 11, the stability and accuracy of the measurement optical path can be guaranteed, and measurement errors caused by light deflection can be avoided.

[0039] Please see the attached Figure 1 -Attached Figure 7 The calculation formula of the thickness of the transparent plate 23 is as follows: t = (n0-1) × L × θ / n1, where t is the thickness of the transparent plate 23, n0 is the refractive index of the material of the upper wedge mirror 21 and the lower wedge mirror 11, θ is the wedge angle of the upper wedge mirror 21 and the lower wedge mirror 11, and the unit is radian, n0 is the refractive index of the material of the transparent plate 23, and L is the distance moved by the upper wedge mirror 21.

[0040] Specifically, the thickness of the transparent plate 23 can be calculated using the above formula. This does not require complex measuring equipment and calculation processes, making it easy to use in practical applications. Furthermore, these parameters are relatively easy to obtain, reducing measurement difficulty and improving measurement efficiency. Since the wedge angle is very small, the refraction angle is calculated based on an approximate paraxial optical path. When the wedge angle is 1 degree, the deviation between the radian value of the wedge angle θ and the SINθ and TANθ values ​​is less than one ten-thousandth. Therefore, radians are used in place of SINθ and TANθ in the optical path calculation for approximate calculation.

[0041] Please see the attached Figure 1 -Attached Figure 4 A device for measuring the thickness of a transparent flat plate using a non-contact method comprises a shell 1, a light source 2 is provided at the middle position of the inner wall of the shell 1, a fixing plate 1 3 is fixedly connected to the inside of the shell 1, a condenser 4 is provided on the inner wall of the fixing plate 1 3, a fixing plate 2 5 is fixedly connected to the inner wall of the shell 1, a graticule 6 is provided on the inner wall of the fixing plate 2 5, a connecting frame 7 is fixedly connected to the inside of the shell 1, a dichroic prism 8 is provided on the inner wall of the connecting frame 7, a fixing plate 3 9 is fixedly connected to the inner wall of the shell 1, an objective lens group 10 is provided on the inner wall of the fixing plate 3 9, baffles 26 are fixedly connected to both sides of the inner wall of the shell 1, a stopper 14 is slidably connected to the inner wall of the baffle 26, a lower wedge mirror 11 is fixedly connected to the outer wall of the stopper 14, and the outer wall of the lower wedge mirror 11 is fixedly connected. It is connected with a connecting plate 12, the inner wall of which is provided with a bolt 13, the inner wall of the outer shell 1 is provided with a motor 16, the output end of the motor 16 is provided with a threaded column 17, the outer wall of the threaded column 17 is threadedly connected with a threaded block 18, the upper surface of the threaded block 18 is fitted with a connecting plate 2 19, the inner wall of the connecting plate 2 19 is provided with a bolt 20, the outer wall of the bolt 20 is provided with a slider 15, the outer wall of the bolt 20 is fixedly connected with an upper wedge mirror 21, the inner wall of the outer shell 1 is fixedly connected with a support frame 22, the upper surface of the support frame 22 is fitted with a transparent flat plate 23, the interior of the outer shell 1 is provided with a split-image focusing screen 24, the inner wall of the outer shell 1 is provided with a CCD camera 25, and the split-image focusing screen 24 is located directly in front of the CCD camera 25.

[0042] Specifically, the housing 1 supports and fixes the whole, and the light emitted by the light source 2 is converged into parallel lines through the condenser 4, wherein the fixing plate 1 3 is fixed to the inner wall of the housing 1 to limit the position of the condenser 4. On the one hand, it ensures that the condenser 4 will not be moved by external force, which will cause deviation in the measurement result, and on the other hand, it ensures that the condenser 4 will not fall. The light other than the shadow caused by the cross image blocking the grating plate 6 is transmitted to the dichroic prism 8, and then the dichroic prism 8 reflects the light to the objective lens group 10, wherein the fixing plate 2 5 limits the grating plate 6, prevents the grating plate 6 from falling, and ensures that the grating plate 6 will not be shaken and swayed during operation, which will cause the cross image covering part to shift, resulting in error in the measurement result. The frame 7 limits the dichroic prism 8 to prevent it from falling, and then converges the light through the objective lens group 10. The fixed plate three 9 supports and limits the objective lens group 10, and converges the light on the front and back surfaces of the transparent flat plate 23 respectively through the lower wedge mirror 11 and the connecting plate one 12, and the reflected light changes direction through the dichroic prism 8, refracts onto the split-image focusing screen 24, and is imaged on the CCD camera 25. The optical signal is converted into an electrical signal by the CCD camera 25, wherein, according to the coincidence degree of the split image, the motor 16 is started to drive the threaded column 17 to rotate, wherein the motor 16 serves as a driving source to drive the threaded column 17 to rotate, and then drives the threaded block 18 to move, because the threaded block 18 is connected to the connecting plate two 19. The upper wedge mirror 21 is connected by bolt 20, thereby driving the upper wedge mirror 21 to move along the wedge surface of the lower wedge mirror 11. The slider 15 and the upper wedge mirror 21 are also connected by connecting plate 2 19 and bolt 20 to ensure the stability of the upper wedge mirror 21 during movement, so that the upper and lower split images overlap, and then the thickness of the transparent plate 23 is calculated according to the formula. When the thickness and tolerance accuracy of the transparent plate 23 are different, the connecting plate 2 19 is unscrewed and removed, so that the bolt 20 and the connecting plate 2 19 are no longer connected to the slider 15 and the threaded block 18, and the upper wedge mirror 21 is taken out. Then, the bolt 13 is unscrewed and removed, so that the bolt 13 no longer fixes the connecting plate 12 and the lower wedge mirror 11, and then the lower wedge mirror 11 is taken out. During installation, first, the block 14 on the outer wall of the lower wedge mirror 11 is fitted into the inner wall of the baffle 26, and the connecting plate 12 is fitted into the outer wall of the baffle 26, and the bolt 13 is tightened to fix the lower wedge mirror 11, and then the connecting plates 2 19 on both sides of the outer wall of the upper wedge mirror 21 are fitted into the outer walls of the slider 15 and the threaded block 18, and the threaded block 18, the slider 15 and the connecting plate 2 19 are fixed with the bolt 20, so as to measure the thickness of the transparent plate 23, so that only the motor 16 needs to be started to control the movement of the upper wedge mirror 21, and the adjustment of the upper wedge mirror 21 is simple and the overall cost is low. At the same time, it is convenient to replace the upper wedge mirror 21 and the lower wedge mirror 11 according to the thickness and tolerance accuracy of the transparent plate 23, thereby improving the applicability of the device.

[0043] Please see the attached Figure 1 -Attached Figure 3 The condenser 4 is located directly above the light source 2 , the graticule 6 is located directly above the condenser 4 , the dichroic prism 8 is located directly above the graticule 6 , and the objective lens group 10 is located directly above the dichroic prism 8 .

[0044] Specifically, by limiting the positions of the light source 2, the condenser 4, the reticle 6, the beam splitter prism 8, and the objective lens group 10, it is helpful for technicians to accurately install the various optical components when building a measuring device, ensure the correct direction of the light path, and avoid abnormal light propagation due to incorrect component positions. It is also convenient for people who are new to the measurement method to understand the order and path of the light passing through the various components in sequence. When performing equipment debugging, maintenance or troubleshooting, they can quickly locate the position of the components and improve work efficiency.

[0045] Please see the attached Figure 2 -Attached Figure 4 The inclination angle of the threaded column 17 is the same as the angle of the wedge surface of the lower wedge mirror 11, and the outer wall of the threaded block 18 is slidably connected to the inner wall of the shell 1.

[0046] Specifically, by setting the inclination of the threaded column 17 to be the same as the angle of the wedge surface of the lower wedge mirror 11, when the motor 16 drives the threaded column 17 to rotate and the threaded block 18 and the upper wedge mirror 21 to move, the distance between the lower wedge mirror 11 and the upper wedge mirror 21 will not change. By sliding the threaded block 18 on the inner wall of the housing 1, it is ensured that the threaded block 18 will not rotate when the threaded column 17 rotates, so that the threaded block 18 can only perform linear motion.

[0047] Please see the attached Figure 2 -Attached Figure 4 The outer wall of the slider 15 is slidably connected to the inner wall of the housing 1 , and the outer wall of the connecting plate 2 19 is in contact with the outer wall of the slider 15 .

[0048] Specifically, by setting the slider 15 to slide on the inner wall of the shell 1, the upper wedge mirror 21 is ensured to be more stable when moving and will not shake. The connecting plate 2 19 is fitted with the slider 15 and then fixed with the bolt 20 to prevent the upper wedge mirror 21 from shaking up and down.

[0049] Please see the attached Figure 4 The outer wall of the bolt 13 is set on the inner wall of the baffle 26, and the outer wall of the connecting plate 12 is attached to the outer wall of the baffle 26.

[0050] Specifically, by setting the connecting plate 12 and the baffle 26 to fit together, and then fixing the connecting plate 12 and the baffle 26 with the bolt 13, the shaking of the lower wedge mirror 11 is prevented, thereby ensuring the stable light propagation.

[0051] Please see the attached Figure 5 and attached Figure 6 When the upper wedge-shaped mirror 21 moves, it always keeps moving parallel to the wedge surface of the lower wedge-shaped mirror 11, and the distance between the upper wedge-shaped mirror 21 and the lower wedge-shaped mirror 11 remains unchanged.

[0052] Specifically, the above-described features ensure the stability and repeatability of the propagation path of light as it passes through the upper wedge mirror 21 and the lower wedge mirror 11, avoiding abnormal light refraction and resulting optical path confusion due to the non-parallel movement of the upper wedge mirror 21. This ensures that the light reliably converges on the front and rear surfaces of the transparent plate 23, thereby guaranteeing the accuracy of the measurement results. Furthermore, the stable mirror spacing ensures a stable and predictable optical path difference for light propagating through the upper wedge mirror 21 and the lower wedge mirror 11. This is crucial for measuring the thickness of the transparent plate 23 based on changes in the optical path difference. It effectively avoids additional errors introduced by distance changes and ensures the reliability of calculating the thickness of the transparent plate 23 based on the movement distance of the upper wedge mirror 21.

[0053] Please see the attached Figure 7 The split-image focusing screen 24 is used to determine the alignment degree of light convergence on the surface of the transparent plate 23. By observing the overlap of the upper and lower split images on the split-image focusing screen 24, it is determined whether the light is accurately converged on the front and back surfaces of the transparent plate 23.

[0054] Specifically, when measuring the thickness of the transparent plate 23, by accurately judging whether the light is focused in front of and behind the transparent plate 23, and judging the split-image coincidence of the surface split-image focusing screen 24, the subjective judgment of the light convergence clarity is transformed into a relatively objective split-image coincidence observation. Compared with simply relying on observing the clarity of the cross image, this method is less affected by the subjective factors of the operator, can effectively reduce judgment errors, and thus improve measurement accuracy.

[0055] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for measuring the thickness of a transparent plate using a non-contact method, characterized in that: The following steps are involved: Constructing a measuring optical path: energizing the light source (2) so that the light from the light source (2) passes sequentially through the condenser (4), the graticule (6), the beam splitter (8), the objective lens group (10), and then converges onto the optical plane of the transparent plate (23) through the lower wedge mirror (11) and the upper wedge mirror (21); Light adjustment: adjust the light path so that the normal line of the optical plane of the transparent plate (23) is parallel to the light path, ensure that the reflected light from the optical plane of the transparent plate (23) is returned symmetrically with the normal line of the incident light, change the direction of the light path through the reflection of the beam splitter prism (8), pass through the split image on the split image focusing screen (24) and form an image on the CCD camera (25); Measuring operation: by starting the motor (16) to drive the threaded column (17) to rotate, the threaded block (18) and the second connecting plate (19) are driven to move, so that the upper wedge mirror (21) is adjusted along the direction of the lower wedge mirror (11), so that the light is respectively converged on the front and rear surfaces of the transparent flat plate (23), and the convergence alignment standard is that the upper and lower split images on the split image focusing screen (24) overlap.

2. The method for measuring the thickness of a transparent plate using a non-contact method according to claim 1, wherein: The upper wedge-shaped mirror (21) and the lower wedge-shaped mirror (11) are made of the same material and have the same angle, and the surfaces of the upper wedge-shaped mirror (21) and the lower wedge-shaped mirror (11) facing each other are perpendicular to the optical path.

3. The method for measuring the thickness of a transparent plate using a non-contact method according to claim 1, wherein: The calculation formula of the thickness of the transparent plate (23) is as follows: t=(n0-1)×L×θ / n1, wherein t is the thickness of the transparent plate (23), n0 is the refractive index of the material of the upper wedge mirror (21) and the lower wedge mirror (11), θ is the wedge angle of the upper wedge mirror (21) and the lower wedge mirror (11), the unit is radian, n0 is the refractive index of the material of the transparent plate (23), and L is the distance that the upper wedge mirror (21) moves.

4. A device for measuring the thickness of a transparent plate using a non-contact method, characterized in that: A method for measuring the thickness of a transparent flat plate using a non-contact method as described in any one of claims 1 to 3, comprising a housing (1), a light source (2) being provided at the middle of the inner wall of the housing (1), a fixing plate 1 (3) being fixedly connected to the interior of the housing (1), a condenser (4) being provided on the inner wall of the fixing plate 1 (3), a fixing plate 2 (5) being fixedly connected to the inner wall of the housing (1), a graticule (6) being provided on the inner wall of the fixing plate 2 (5), and the interior of the housing (1). A connecting frame (7) is fixedly connected, and a dichroic prism (8) is provided on the inner wall of the connecting frame (7). A fixing plate (9) is fixedly connected to the inner wall of the housing (1), and an objective lens group (10) is provided on the inner wall of the fixing plate (9). Baffles (26) are fixedly connected to both sides of the inner wall of the housing (1), and a stopper (14) is slidably connected to the inner wall of the baffle (26). The outer wall of the stopper (14) is fixedly connected to a lower wedge mirror (11), and the lower wedge mirror (11) is fixedly connected to the inner wall of the housing (1). ) is fixedly connected to the outer wall of a connecting plate 1 (12), the inner wall of the connecting plate 1 (12) is provided with a bolt 1 (13), the inner wall of the housing (1) is provided with a motor (16), the output end of the motor (16) is provided with a threaded column (17), the outer wall of the threaded column (17) is threadedly connected to a threaded block (18), the upper surface of the threaded block (18) is affixed to a connecting plate 2 (19), the inner wall of the connecting plate 2 (19) is provided with a bolt 2 (20), the bolt 2 The outer wall of the housing (20) is provided with a slider (15), the outer wall of the bolt 2 (20) is fixedly connected with an upper wedge mirror (21), the inner wall of the housing (1) is fixedly connected with a support frame (22), the upper surface of the support frame (22) is attached with a transparent flat plate (23), the interior of the housing (1) is provided with a split-image focusing screen (24), the inner wall of the housing (1) is provided with a CCD camera (25), and the split-image focusing screen (24) is located directly in front of the CCD camera (25).

5. A method for measuring the thickness of a transparent plate using a non-contact method according to the condenser lens (4), characterized in that: The condenser (4) is located directly above the light source (2), the graticule (6) is located directly above the condenser (4), the beam splitter prism (8) is located directly above the graticule (6), and the objective lens group (10) is located directly above the beam splitter prism (8).

6. The method for measuring the thickness of a transparent plate using a non-contact method according to claim 4, wherein: The inclination angle of the threaded column (17) is the same as the angle of the wedge surface of the lower wedge mirror (11), and the outer wall of the threaded block (18) is slidably connected to the inner wall of the housing (1).

7. The method for measuring the thickness of a transparent plate using a non-contact method according to claim 4, wherein: The outer wall of the slider (15) is slidably connected to the inner wall of the housing (1), and the outer wall of the second connecting plate (19) is in contact with the outer wall of the slider (15).

8. The method for measuring the thickness of a transparent plate using a non-contact method according to claim 4, wherein: The outer wall of the bolt 1 (13) is arranged on the inner wall of the baffle (26), and the outer wall of the connecting plate 1 (12) is attached to the outer wall of the baffle (26).

9. The method for measuring the thickness of a transparent plate using a non-contact method according to claim 4, wherein: When the upper wedge-shaped mirror (21) moves, it always keeps moving parallel to the wedge surface of the lower wedge-shaped mirror (11), and the distance between the upper wedge-shaped mirror (21) and the lower wedge-shaped mirror (11) remains unchanged.

10. The method for measuring the thickness of a transparent plate using a non-contact method according to claim 4, wherein: The split image focusing screen (24) is used to judge the degree of alignment of light rays converging on the surface of the transparent flat plate (23), and to determine whether the light rays are accurately converging on the front and rear surfaces of the transparent flat plate (23) by observing the overlap of the upper and lower split images on the split image focusing screen (24).

Images