Detection device for detecting micro lens area of lens

Abstract

The embodiment of the utility model provides a detection device for detecting a micro lens area of a lens, the detection device comprises a light source, a concave mirror, a mounting bracket and an image acquisition device, the light source is used for emitting a light beam; the concave mirror is provided with a reflecting surface for reflecting light beams; the mounting bracket is used for mounting a lens; an image acquisition device; an image acquisition area of the image acquisition device faces the reflecting surface, the light source can emit light beams towards the reflecting surface, the image acquisition area can receive the light beams emitted by the light source reflected by the reflecting surface, and the mounting bracket is arranged between the light source and the reflecting surface, so that the light beams emitted by the light source can penetrate through the lens and then reach the reflecting surface. According to the detection device provided by the embodiment of the utility model, the light and shade texture on the light spot image formed by the light beam acquired by the image acquisition area is directly utilized, so that the purpose of identifying the shapes and distribution of micro lenses and flaws in the lens is intuitively realized; and non-destructive detection of the micro lens area is realized.

Description

Technical Field

[0001] This application relates to the field of optical detection technology, and particularly to a detection device for detecting the microlens area of a lens. Background Art

[0002] With the rapid development of optical technology, the application fields of lenses have been increasingly broadened. Especially in the fields of high-precision imaging, optical communication, biomedicine, etc., the performance and quality of lenses have become the key factors determining their application effects.

[0003] For lenses with a microlens structure, the accurate detection of their microlens areas is particularly important. The design of the microlens area has become increasingly complex, not only limited to the traditional dot arrangement, but also including various forms such as annular arrangement and honeycomb arrangement. While these complex microlens structures improve the performance of the lenses, they also pose great challenges to the detection work.

[0004] Traditional microlens area detection technologies, such as interference detection, have problems such as low accuracy, complex operation, and long time consumption during detection, posing great challenges to the detection work. Therefore, providing a detection device with more accurate detection results for the microlens area is an urgent problem to be solved in the field of optical detection technology. Summary of the Utility Model

[0005] In view of this, embodiments of the present utility model expect to provide a detection device for detecting the microlens area of a lens, which can accurately detect the microlens area of the lens.

[0006] To achieve the above object, the technical solution of the embodiments of this application is realized as follows:

[0007] Embodiments of the present utility model provide a detection device for detecting the microlens area of a lens, and the detection device includes:

[0008] A light source for emitting a light beam;

[0009] A concave mirror provided with a reflecting surface for reflecting the light beam;

[0010] A mounting bracket for mounting the lens;

[0011] An image acquisition device;

[0012] The image acquisition area of the image acquisition device faces the reflecting surface, the light source can emit a light beam towards the reflecting surface, the image acquisition area can receive the light beam emitted by the light source reflected by the reflecting surface, and the mounting bracket is arranged between the light source and the reflecting surface so that the light beam emitted by the light source can pass through the lens and then reach the reflecting surface.

[0013] In some embodiments, the distance between the light source and the reflecting surface is a first distance, and the first distance is 1.8 to 2.2 times the focal length of the concave mirror.

[0014] In some embodiments, the distance between the mounting bracket and the reflecting surface does not exceed the focal length of the concave mirror.

[0015] In some embodiments, the optical axis of the concave mirror passes through the image acquisition area.

[0016] In some embodiments, the detection device further includes a first driving device, and a first driving part of the first driving device is drivingly connected to the image acquisition device to drive the image acquisition device to move along the relative direction between the image acquisition area and the reflecting surface.

[0017] In some embodiments, the detection device further includes a light-shielding member, and at least a part of the light-shielding member is located between the image acquisition area and the reflecting surface to block part of the light beam reflected by the reflecting surface.

[0018] In some embodiments, the light-shielding member is located on one side perpendicular to the orientation of the image acquisition area of the image acquisition area, and the light source is located on the other side.

[0019] In some embodiments, the distance between the light source and the reflecting surface is a first distance, and the distance between the light-shielding member and the reflecting surface is a second distance. The first distance is 1.8 to 2.2 times the focal length of the concave mirror, and the second distance is the same as the first distance.

[0020] In some embodiments, the light-shielding rate of the light-shielding member is 50% to 70%.

[0021] In some embodiments, the detection device further includes a second driving device, and a second driving part of the second driving device is drivingly connected to the light-shielding member to drive the light-shielding member to move perpendicular to the orientation of the image acquisition area.

[0022] In the detection device according to the embodiment of the present invention, by directly using the bright and dark textures on the spot image formed by the light beam collected in the image acquisition area, the purpose of identifying the shape and distribution of the microlenses and defects in the lens is intuitively realized. Using the principle of optical imaging, the microlenses and defects are accurately corresponding to the textures of the spot image one by one, which is beneficial to improving the accuracy of detection; during the detection process, there is no need to contact the lens, realizing non-destructive detection of the microlens area, avoiding any damage to the spectacle lens or affecting its performance, and ensuring the integrity and quality of the product. Description of the Drawings

[0023] Figure 1Schematic diagram of the arrangement of the detection device and the lens in the first embodiment of the present utility model. Among them, the long dashed line represents the light beam that can be received by the image acquisition area after reflection, and the short dashed line represents the light beam that cannot be received by the image acquisition area after reflection;

[0024] Figure 2 Schematic diagram of the arrangement of the detection device and the lens in the second embodiment of the present utility model;

[0025] Figure 3 Schematic diagram of the arrangement of the detection device and the lens in the third embodiment of the present utility model;

[0026] Figure 4 Schematic diagram of the arrangement of the image acquisition device, the lens, the concave mirror and the first driving device in an embodiment of the present utility model;

[0027] Figure 5 Schematic diagram of the image acquisition device, the shielding member, the first driving device and the second driving device in an embodiment of the present utility model.

[0028] Explanation of reference numerals

[0029] 10. Light source; 10a. Light beam; 20. Concave mirror; 20a. Reflecting surface; 20b. Focus; 20c. Optical axis; 20d. Converging point; 30. Mounting bracket; 40. Image acquisition device; 40a. Image acquisition area; 50. Lens; 60. Light shielding member; 70. First driving device; 71. First driving part; 80. Second driving device; 81. Second driving part; 90. First telescopic rod; 91. Second telescopic rod. Detailed implementation manners

[0030] It should be noted that, without conflict, the embodiments and the technical features in the embodiments in the present application can be combined with each other. The detailed description in the detailed implementation manners should be understood as an explanatory illustration of the purpose of the present application and should not be regarded as an improper limitation of the present application.

[0031] In the description of the present application, the orientation or positional relationship of "the orientation of the image acquisition area" is based on the orientation or positional relationship shown by the arrow X in the attached Figure 1 and Figure 4 The orientation or positional relationship of "the vertical direction" is based on the orientation or positional relationship shown by the arrow Y in the attached Figure 3 and Figure 4 It should be understood that these orientation terms are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0032] An embodiment of the present utility model provides a detection device for detecting the microlens area of a lens 50, which can be used at least to detect the distribution arrangement of microlenses, the defects of microlenses, and the defects of the substrate of the lens 50 in the microlens area of the lens 50.

[0033] Referring to Figures 1 to 3 , the detection device includes a light source 10, a concave mirror 20, a mounting bracket 30, and an image acquisition device 40.

[0034] The light source 10 is used to emit a light beam 10a; the concave mirror 20 is provided with a reflecting surface 20a for reflecting the light beam 10a; the mounting bracket 30 is used to mount the lens 50; the image acquisition area 40a of the image acquisition device 40 faces the reflecting surface 20a, the light source 10 can emit the light beam 10a towards the reflecting surface 20a, the image acquisition area 40a can receive the light beam 10a emitted by the light source 10 reflected by the reflecting surface 20a, and the mounting bracket 30 is arranged between the light source 10 and the reflecting surface 20a so that the light beam 10a emitted by the light source 10 can pass through the lens 50 and then reach the reflecting surface 20a.

[0035] The specific type of the light source 10 is not limited, for example, an LED (light emitting diode) lamp.

[0036] The light emitted by the light source 10 is monochromatic light, which is convenient for debugging during the detection of the lens 50 and also avoids interference between different color regions and different brightness regions in the image collected by the image acquisition device 40.

[0037] The reflecting surface 20a of the concave mirror 20 can be a spherical surface or a parabolic surface.

[0038] The image acquisition area 40a of the image acquisition device 40 is used to receive the light beam 10a to form a spot image.

[0039] A part of the light beam 10a emitted by the light source 10 propagates towards the concave mirror 20, passes through the lens 50 and reaches the reflecting surface 20a, then the light beam 10a is reflected, and the reflected light beam 10a is received by the image acquisition device 40.

[0040] During the process of the light beam 10a passing through the lens 50, theoretically, if the refractive indices of each area on the lens 50 are the same, the change amplitude of the path of the light beam 10a passing through each area of the lens 50 is the same, so that after the light beam 10a passing through each area of the lens 50 is reflected by the reflecting surface 20a, the change in brightness of the spot image formed by the light beam 10a received by the image acquisition area 40a is small.

[0041] However, in reality, the lens 50 includes different types of regions such as regions provided with microlenses, regions with defects on the lens 50, and regions on the lens 50 that are intact without microlenses. The refractive indices of these regions for the light beam 10a are different from each other, and the variation amplitudes of the paths of the light beam 10a after passing through these regions are inconsistent. Therefore, compared with the light beam 10a passing through some regions, the light beam 10a passing through other regions can be more received by the image acquisition region 40a after being reflected by the reflecting surface 20a, thereby forming bright and dark textures on the spot image. Different textures respectively correspond to different types of regions such as the regions provided with microlenses on the lens 50, the regions with defects on the lens 50, and the regions on the lens 50 that are intact without microlenses. That is to say, by using the schlieren imaging principle, the purpose of intuitively identifying the distribution and shape of the microlenses on the lens 50, and the distribution and shape of the defects through the shape and distribution of the bright and dark textures on the spot image is achieved.

[0042] In the detection device in the embodiment of the present utility model, by directly using the bright and dark textures on the spot image formed by the light beam 10a collected by the image acquisition region 40a, the purpose of intuitively identifying the shapes and distributions of the microlenses and defects in the lens 50 is achieved. By using the principle of optical imaging, the microlenses and defects are accurately corresponding to the textures of the spot image one by one, which is beneficial to improving the accuracy of detection; during the detection process, there is no need to contact the lens 50, and non-destructive detection of the microlens region is achieved, avoiding any damage to the spectacle lens 50 or affecting its performance, and ensuring the integrity and quality of the product.

[0043] The specific type of the image acquisition device 40 is not limited. For example, the image acquisition device 40 is a CMOS (Complementary Metal Oxide Semiconductor) camera, and its lens forms the image acquisition region 40a. The lens is a variable telephoto lens for magnifying or reducing the photographed reflecting surface 20a.

[0044] It can be understood that the image formed by the light beam 10a emitted by the light source 10 after being reflected by the reflecting surface 20a needs to be suitable for being received by the image acquisition region 40a.

[0045] In some embodiments, referring to Figure 1 , the distance between the light source 10 and the reflecting surface 20a is a first distance, and the first distance is 1.8 times to 2.2 times the focal length of the concave mirror 20. That is to say, the first distance is L1, the focal length is F, and 1.8F ≤ L1 ≤ 2.2F.

[0046] In the state of F < L1 < 2F, the optical image formed by the light beam 10a emitted by the light source 10 after being reflected by the reflecting surface 20a is an inverted real image, and the image is larger than the actual size of the light source 10.

[0047] When in the state where L1 = 2F, the optical image formed after the light beam 10a emitted by the light source 10 is reflected by the reflecting surface 20a is an inverted real image, and the image is equal to the actual size of the light source 10.

[0048] When in the state where L1 > 2F, the optical image formed after the light beam 10a emitted by the light source 10 is reflected by the reflecting surface 20a is an inverted real image, and the image is equal to the actual size of the light source 10.

[0049] Thus, when in the state where 1.8F ≤ L1 ≤ 2.2F, the optical image formed by the light beam 10a reflected by the light source 10 is a real image, so that the image acquisition area 40a can acquire the spot image, and the size of the formed spot image is substantially the same as the size of the light source 10, which helps to realize the accurate detection of the microlens area of the lens 50.

[0050] The specific relationship between the first distance and the focal length of the concave mirror 20 can be L1 = 1.8F, L1 = 1.9F, L1 = 2F, L1 = 2.1F, L1 = 2.2F, etc.

[0051] In some embodiments, referring to Figure 4 , the distance between the mounting bracket 30 and the reflecting surface 20a does not exceed the focal length of the concave mirror 20. That is to say, the distance between the mounting bracket 30 and the reflecting surface 20a is L2, and L2 ≤ F.

[0052] Thus, it is beneficial to make more parts of the image generated by the lens 50 be within the range of the spot image generated by the light source 10 in the image acquired in the image acquisition area 40a, so as to more comprehensively reflect the arrangement mode of the microlenses on the lens 50.

[0053] In some embodiments, in the projection perpendicular to the optical axis 20c of the concave mirror 20, the projection of the lens 50 is completely located within the projection of the reflecting surface 20a, so that the image generated by the lens 50 can be completely within the range of the spot image generated by the light source 10.

[0054] In some embodiments, referring to Figure 2 , the optical axis 20c of the concave mirror 20 passes through the image acquisition area 40a.

[0055] Thus, in the projection perpendicular to the optical axis 20c of the concave mirror 20, at least part of the projection of the reflecting surface 20a coincides with the projection of the image acquisition area 40a. By adjusting the distance between the image acquisition area 40a and the reflecting surface 20a along the extension direction of the optical axis 20c, it is beneficial to make the spot image completely fill the image of the reflecting surface 20a in the image acquired in the image acquisition area 40a, which helps to more clearly reflect the microlens area of the lens 50 in the spot image.

[0056] In some embodiments, referring to Figure 4 and Figure 5 , the detection device further includes a first driving device 70. The first driving part 71 of the first driving device 70 is drivingly connected to the image acquisition device 40 to drive the image acquisition device 40 to move in the relative direction between the image acquisition area 40a and the reflection surface 20a.

[0057] In this way, by driving the image acquisition device 40 to move through the first driving part 71, it is beneficial to adjust the size of the spot image in the image acquired in the image acquisition area 40a by adjusting the distance between the image acquisition area 40a and the reflection surface 20a, so that the spot image completely fills the image of the reflection surface 20a, which helps to more clearly reflect the microlens area of the lens 50 in the spot image.

[0058] The specific form of the first driving device 70 is not limited. For example, the first driving device 70 includes a first slide rail and a first slide table. The first slide table can slide on the first slide rail. The extending direction of the first slide rail is the relative direction between the image acquisition area 40a and the reflection surface 20a, and the first slide table forms the first driving part 71.

[0059] It can be understood that after the first slide table moves to a suitable position, the position of the first slide table is locked to reduce the adverse impact on the detection caused by the movement of the first slide table during subsequent detection.

[0060] In some embodiments, referring to Figure 2 , the relative direction between the image acquisition area 40a and the reflection surface 20a is the extending direction of the optical axis 20c.

[0061] In some embodiments, referring to Figure 3 and Figure 5 , the detection device further includes a light shielding member 60. At least part of the light shielding member 60 is located between the image acquisition area 40a and the reflection surface 20a to block part of the light beam 10a reflected by the reflection surface 20a.

[0062] When the light shielding member 60 blocks part of the light beam 10a that could originally be received by the image acquisition area 40a, the contrast of the bright and dark textures on the spot image is improved, so that it is convenient to more clearly observe the positions of the microlens area and the defect area on the lens 50.

[0063] The specific material of the light shielding member 60 is not limited, such as metal, engineering plastic, etc.

[0064] The specific shape of the light shielding member 60 is not limited. For example, it is in the shape of a blade, and the thickness direction of the light shielding member 60 is the relative direction between the image acquisition area 40a and the reflection surface 20a.

[0065] In some embodiments, referring toFigure 3 , the light-shielding member 60 is located on one side of the image acquisition area 40a perpendicular to the orientation of the image acquisition area 40a, and the light source 10 is located on the other side.

[0066] In this way, the probability that the light-shielding member 60 interferes with the light source 10 and thus blocks the light source 10 during the movement in the direction perpendicular to the orientation of the image acquisition area 40a is reduced, which is beneficial to increasing the movement range of the light-shielding member 60 so as to further adjust the contrast according to the acquired spot image, thereby facilitating the more clearly observing the positions of the microlens area and the defect area on the lens 50.

[0067] In some embodiments, referring to Figure 3 , the distance between the light source 10 and the reflecting surface 20a is the first distance, the distance between the light-shielding member 60 and the reflecting surface 20a is the second distance, the first distance is 1.8 to 2.2 times the focal length of the concave mirror 20, and the second distance is the same as the first distance. That is, the second distance is L3, and L3 = L1.

[0068] In this way, the light-shielding member 60 is located near the image formed by the light source 10, which is beneficial to enabling the light-shielding member 60 to block more reflected light beams 10a by moving only a small distance, thereby facilitating the adjustment of the contrast of the spot image.

[0069] In some embodiments, referring to Figure 3 , the light-shielding member is located at the position of the convergence point 20d formed by the reflected light beam 10a, which is beneficial to enabling the light-shielding member 60 to block more reflected light beams 10a by moving only a small distance, thereby facilitating the adjustment of the contrast of the spot image.

[0070] The position of the convergence point 20d, that is, the image position formed by the reflected light beam 10a, is determined according to the first distance and the focal length. For example, in an embodiment where the first distance is 2 times the focal length, the distance between the convergence point 20d and the reflecting surface 20a is also 2 times the focal length.

[0071] The first distance, the focal length, and the distance between the convergence point 20d and the reflecting surface 20a satisfy the following formula:

[0072] 1 / f = 1 / v + 1 / u

[0073] In the above formula, f is the focal length, v is the distance between the convergence point 20d and the reflecting surface 20a, and u is the first distance.

[0074] In some embodiments, the light-shielding rate of the light-shielding member 60 is 50% to 70% to improve the contrast and make the light and dark changes in the spot image more obvious.

[0075] The specific value of the light-shielding rate of the light-shielding member 60 can be 50%, 55%, 60%, 65%, 70%, etc.

[0076] The light-shielding rate of the light-shielding member 60, the dimension of the light-shielding member 60 along the relative direction of the image acquisition area 40a and the reflection surface 20a, and the light absorption coefficient of the material of the light-shielding member 60 specifically satisfy the following relationship:

[0077] d = ln(1 - K) / (-α)

[0078] In the formula, d is the dimension of the light-shielding member 60 along the relative direction of the image acquisition area 40a and the reflection surface 20a, K is the light-shielding rate of the light-shielding member 60, and α is the light absorption coefficient of the material of the light-shielding member 60.

[0079] In some embodiments, the illuminance of the light source 10 is 700 lx (lux, lux) to 1000 lx so that the formed spot image is clear.

[0080] The illuminance of the light source 10 can specifically be 700 lx, 750 lx, 800 lx, 850 lx, 900 lx, 950 lx, 1000 lx, etc.

[0081] In some embodiments, referring to Figure 5 , the detection device further includes a second driving device 80. The second driving part 81 of the second driving device 80 is drivingly connected to the light-shielding member 60 to drive the light-shielding member 60 to move perpendicular to the orientation of the image acquisition area 40a.

[0082] In this way, the light-shielding member 60 is driven to move by the second driving part 81 to adjust the shielding effect of the light-shielding member 60 on the light beam 10a, thereby facilitating the adjustment of the contrast of the spot image.

[0083] The specific form of the second driving device 80 is not limited. For example, the second driving device 80 includes a second slide rail and a second slide table. The second slide table can slide on the second slide rail. The extending direction of the second slide rail is perpendicular to the relative direction of the image acquisition area 40a and the reflection surface 20a, and the second slide table forms the second driving part 81.

[0084] It can be understood that after the second slide table moves to a suitable position, the position of the second slide table is locked and fixed to reduce the adverse impact on the detection caused by the movement of the second slide table during subsequent detection.

[0085] In some embodiments provided with the first driving device 70, referring to Figure 5 , the second driving device 80 is provided on the first driving part 71 so that the light-shielding member 60 can move together with the image acquisition device 40.

[0086] In some embodiments provided with the first driving device 70 and the second driving device 80, referring toFigure 5 The detection device further includes a first telescopic rod 90 and a second telescopic rod 91. Both the first telescopic rod 90 and the second telescopic rod 91 can be telescoped in the vertical direction. Two ends of the first telescopic rod 90 along its telescopic direction are respectively connected to the image acquisition device 40 and the first driving part 71, and two ends of the second telescopic rod 91 along its telescopic direction are respectively connected to the light shielding member 60 and the second driving part 81, so as to respectively adjust the positions of the image acquisition device 40 and the light shielding member 60 in the vertical direction to adapt to the position of the optical axis 20c of the concave mirror 20.

[0087] In some embodiments, the detection device further includes a display device. The display device is electrically connected to the image acquisition device 40. The display device has a display area for displaying the spot image acquired by the image acquisition device 40, so as to more intuitively display the light and dark texture on the lens 50.

[0088] In some embodiments, the detection device further includes a calculation device. The calculation device can interact with the image acquisition device 40. The calculation device is used for preprocessing the acquired spot image, including operations such as removing noise in the image and enhancing the contrast.

[0089] Common image preprocessing techniques include median filtering, Gaussian filtering, histogram equalization, etc. Next, the edge detection algorithm Canny is used to detect the edge information of the microlens structure in the image. Then, the contour extraction algorithm is used to extract the contour information of the microlens structure for subsequent feature extraction. After contour extraction, morphological operations are used to further process the image to better extract the feature information of the microlens structure. Morphological operations include erosion, dilation, opening operation, closing operation, etc. These operations can help remove small-scale noise in the spot image, fill holes in the microlens structure, etc., so as to enhance the features of the image. Based on the processed spot image, an appropriate feature extraction algorithm is used to extract the size or duty cycle information of the microlens structure. Common feature extraction methods include contour analysis, region growing algorithm, etc. Through these methods, relevant parameters of the microlens structure, such as diameter, pitch, duty cycle, etc., can be obtained. Finally, data analysis is performed on the extracted feature information to obtain statistical results such as the size distribution or duty cycle distribution of the microlens structure. Statistical methods can be used to analyze the data, such as mean, variance, frequency distribution, etc. Through these analyses, the morphological characteristics of the microlens structure can be deeply understood.

[0090] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A detection device for detecting a microlens area of ​​a lens, characterized in that: The detection device comprises: A light source for emitting a light beam; A concave mirror having a reflecting surface for reflecting the light beam; A mounting bracket for mounting the lens; An image acquisition device; The image acquisition area of ​​the image acquisition device faces the reflective surface, the light source can emit a light beam toward the reflective surface, the image acquisition area can receive the light beam emitted by the light source reflected by the reflective surface, and the mounting bracket is arranged between the light source and the reflective surface so that the light beam emitted by the light source can pass through the lens and reach the reflective surface.

2. The detection device according to claim 1, characterized in that: The distance between the light source and the reflecting surface is a first distance, and the first distance is 1.8 to 2.2 times the focal length of the concave mirror.

3. The detection device according to claim 1, characterized in that: The distance between the mounting bracket and the reflecting surface does not exceed the focal length of the concave mirror.

4. The detection device according to claim 1, characterized in that: The optical axis of the concave mirror passes through the image acquisition area.

5. The detection device according to claim 1, characterized in that: The detection device further comprises a first driving device, wherein a first driving portion of the first driving device is drivingly connected to the image acquisition device to drive the image acquisition device to move along a relative direction between the image acquisition area and the reflective surface.

6. The detection device according to claim 1, characterized in that: The detection device further includes a shading member, at least a portion of which is located between the image acquisition area and the reflective surface to shield a portion of the light beam reflected by the reflective surface.

7. The detection device according to claim 6, characterized in that: The shading member is located on one side of the image acquisition region that is perpendicular to the direction of the image acquisition region, and the light source is located on the other side.

8. The detection device according to claim 6, characterized in that: The distance between the light source and the reflecting surface is a first distance, the distance between the shading element and the reflecting surface is a second distance, the first distance is 1.8 to 2.2 times the focal length of the concave mirror, and the second distance is the same as the first distance.

9. The detection device according to claim 6, characterized in that: The shading rate of the shading member is 50% to 70%.

10. The detection device according to claim 6, characterized in that: The detection device further comprises a second driving device, wherein a second driving portion of the second driving device is drivingly connected to the shading member to drive the shading member to move perpendicularly to the direction of the image acquisition area.

Images