A device and method for detecting the front and back surfaces of an imaging type ultra-small curvature plano-convex lens or plano-concave lens

Abstract

The application discloses a kind of imaging type ultra-small curvature flat convex lens or flat concave lens positive and negative face detection device and method, the detection method of the present application, the distinction of plane and curved surface is realized by imaging method, imaging method includes transmission imaging method, right-angle reflection imaging method and acute-angle reflection imaging method.The imaging type ultra-small curvature flat convex lens or flat concave lens positive and negative face detection method of the present application is simple, easy to operate, and the distinction of curved surface, plane can be realized by specific imaging mode, high efficiency, and accuracy is 100%;The imaging type ultra-small curvature flat convex lens or flat concave lens positive and negative face detection device of the present application is simple in structure, convenient to use, after the optical system of the specific structure of the present application, imaging light spot can be obtained using area array camera, and whether curved surface is upward or plane is upward can be accurately judged by the size of two light spots.

Description

Technical Field

[0001] This invention relates to a device and method for detecting the front and back surfaces of an imaging-type plano-convex lens or plano-concave lens with ultra-small curvature, belonging to the technical field of determining the front and back surfaces of plano-convex lenses or plano-concave lenses. Background Technology

[0002] In production practice, a type of plano-convex or plano-concave lens with extremely small curvature (i.e., extremely large radius of curvature) may appear. Due to the very small curvature, it is impossible to distinguish the front and back of the lens with the naked eye. Moreover, even if one wanted to distinguish them by measuring the sag, the sag is even smaller than the error introduced by height measurement, making it impossible to distinguish the upper and lower surfaces of the plano-convex or plano-concave lens in engineering practice. For example, the difference between the center thickness and the edge thickness of a customer's plano-convex lens product is only 3.5µm. In the production line, to quickly measure the center thickness of the plano-convex lens and then move it to the edge to measure the edge thickness, the flatness of the moving platform must be <+ / -1µm (this is a very high requirement, almost the limit of current industrial technology). If we also consider the measurement accuracy of the ranging tool (or height measuring tool) itself (<+ / -1µm), plus the errors caused by various vibrations in the industrial production environment, it is practically impossible to distinguish the front and back of the plano-convex lens by measuring the height difference between the center and the edge. However, it is necessary to distinguish the front and back of the plano-convex lens in production, which becomes a thorny problem. Through communication with the customer and research before R&D, it was found that there is currently no reliable technical solution. Summary of the Invention

[0003] This invention provides a device and method for detecting the front and back surfaces of an imaging-type ultra-small curvature plano-convex lens or plano-concave lens. By utilizing the minute curvature (or protrusion) difference between the convex surface and the plane, this difference is magnified through imaging, making it detectable and distinguishable by the naked eye or scientific instruments.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A method for detecting the front and back surfaces of an imaging-type ultra-small curvature plano-convex or plano-concave lens, which distinguishes between planes and curved surfaces through imaging methods, including transmission imaging, right-angle reflection imaging, and acute-angle reflection imaging.

[0006] For ease of detection, the acute angle reflection imaging method is the 45-degree reflection imaging method.

[0007] The above transmission imaging method is as follows: the light emitted from the light source passes through the collimating lens and the focusing lens in sequence, then passes through the lens under test, and is magnified by the focusing lens. The size of the imaging spot is used to distinguish between planes and curved surfaces. The imaging spot of the curved surface facing the light source is significantly smaller than the imaging spot of the curved surface facing away from the light source (plane facing the light source). The smaller the radius of curvature, the greater the difference in the diameter of the light spot, and the easier it is to distinguish them.

[0008] The above-mentioned right-angle reflection imaging method is as follows: the light emitted from the light source passes through the collimating lens, is folded by the beam splitter and passes perpendicularly through the lens under test, is then reflected perpendicularly by the reflecting mirror and passes through the sample under test and the beam splitter again, and finally passes through the focusing lens to obtain a focused imaging spot. The size of the imaging spot is used to distinguish between planes and curved surfaces. The imaging spot of a plane facing the beam splitter is significantly larger than the imaging spot of a curved surface facing the beam splitter. The smaller the radius of curvature, the greater the difference in the spot diameter, and the easier it is to distinguish.

[0009] To facilitate identification, the above-mentioned right-angle reflection imaging method uses a focusing lens and then a magnifying relay lens to obtain the imaging spot.

[0010] The acute-angle reflection imaging method described above is as follows: the light emitted from the light source passes through the collimating lens and the focusing lens in sequence, is reflected by the lens under test, and is then magnified by the focusing lens to form an image. The shape and / or size of the image spot are used to distinguish between planes and curved surfaces.

[0011] To facilitate differentiation, the acute-angle reflection imaging method described above distinguishes between planar and curved surfaces by the size of the imaging spot. The imaging spot facing downwards on a curved surface is significantly larger than the imaging spot facing upwards on a curved surface. The smaller the radius of curvature, the greater the difference in spot diameter, and the easier it is to distinguish between them.

[0012] All of the above methods utilize area array cameras to capture imaging light spots.

[0013] A detection device for the front and back surfaces of an imaging-type ultra-small curvature plano-convex lens or plano-concave lens, comprising an output component, a functional component, and a receiving component;

[0014] The functional component is a first focusing lens or a beam splitter; the output component includes a point light source and a collimating lens, and the receiving component includes a second focusing lens and an area array camera.

[0015] The light source, collimating lens, functional components, second focusing lens, and area array camera are arranged sequentially along the direction of light propagation.

[0016] As one implementation scheme, when using the transmission imaging method, the functional components are a first focusing lens, a point light source, a collimating lens, a first focusing lens, a second focusing lens, and an area array camera arranged in sequence along the same direction, with the optical axes of the collimating lens, the first focusing lens, and the second focusing lens overlapping, and the point light source and the area array camera both located on the optical axis.

[0017] The first focusing lens is set up to control the diameter of the light beam, so that the light beam can penetrate the sample with a relatively small aperture. At this time, the light beam can be focused to obtain a focused spot, but the diameter of the spot may be relatively small, which is not conducive to subsequent software judgment. In order to obtain a larger focused spot, a second focusing lens is added. In fact, its function is to act as a relay lens, that is, to magnify the focused spot and make the size of the imaging spot behind the second focusing lens larger, so as to facilitate image acquisition and processing.

[0018] As another implementation scheme, when using the vertical reflection imaging method, the functional component is a beam splitter. The point light source, collimating lens and beam splitter are arranged from left to right, and the area array camera, second focusing lens, beam splitter and reflector are arranged from top to bottom.

[0019] The vertical and horizontal positions of this application are based on the relative positions shown in the attached drawings.

[0020] For ease of testing, the aforementioned beam splitter is a cubic beam splitter composed of two 45° right-angled triangular prisms. The optical axis of the collimating lens forms a 45° angle with the joint of the beam splitter, the optical axis of the collimating lens is perpendicular to the reflecting surface of the reflecting mirror, and the optical axis of the second focusing lens forms a 45° angle with the joint of the beam splitter.

[0021] A magnifying relay mirror can be installed between the second focusing mirror and the area array camera as needed.

[0022] As another implementation scheme, when using the acute angle reflection imaging method, the functional component is a first focusing lens, the optical axes of the collimating lens and the first focusing lens overlap and the angle between them and the horizontal plane is α, 0°<α<90°; the optical axis of the second focusing lens is symmetrical to the optical axis of the first focusing lens and intersects it; the point light source is set on the optical axis of the collimating lens, and the area array camera is set on the optical axis of the second focusing lens.

[0023] The second focusing lens acts as a magnifying relay lens.

[0024] Preferably, α is 45°.

[0025] A method for detecting the front and back surfaces of an imaging-type plano-convex lens or plano-concave lens with ultra-small curvature, utilizing the aforementioned detection device for the front and back surfaces of such a lens, includes the following steps when using transmission imaging:

[0026] 1) Place the lens to be tested between the first focusing lens and the second focusing lens, with one side of the lens facing the point light source and the other side facing the area array camera; the light emitted from the point light source passes through the collimating lens and the first focusing lens, then passes through the lens to be tested, and is magnified and imaged by the second focusing lens. The camera then collects the image spot of the second focusing lens.

[0027] 2) Invert the two sides of the lens to be tested, and use the camera to collect the imaging spot of the second focusing lens according to the method in step 1);

[0028] 3) Compare the size and / or shape of imaging spot one and imaging spot two. When imaging spot one is larger, the side of the lens under test facing the point light source in step 1) is a plane and the other side is a curved surface; when imaging spot two is larger, the side of the lens under test facing the point light source in step 2) is a plane and the other side is a curved surface.

[0029] When using vertical reflection imaging, the detection method includes the following steps:

[0030] 1) Place the lens to be tested between the beam splitter and the reflector, with one side of the lens facing the beam splitter and the other side facing the reflector; the light emitted from the point source is collimated by the collimating lens, then folded down by the beam splitter, passes through the lens to be tested and reaches the reflector, is reflected by the reflector and passes through the sample to be tested and the beam splitter again, and is then focused by the focusing lens. The camera is used to collect the imaging spot of the second focusing lens.

[0031] 2) Invert the two sides of the lens to be tested, and use the camera to collect the imaging spot of the second focusing lens according to the method in step 1);

[0032] 3) Compare the size and / or shape of imaging spot one and imaging spot two. When imaging spot one is larger, the side of the lens under test facing the reflecting mirror in step 1) is curved and the other side is flat. When imaging spot two is larger, the side of the lens under test facing the point reflecting mirror in step 2) is curved and the other side is flat.

[0033] In steps 1) and 2) above, the light spot focused by the focusing lens is then magnified by the magnifying relay lens, and the magnified imaging spot one and imaging spot two are acquired by the camera. This facilitates the acquisition and processing of the imaging spot.

[0034] When using acute-angle reflection imaging, the detection method includes the following steps:

[0035] 1) Place the lens under test at the intersection of the optical axes of the first focusing lens and the second focusing lens, with one side of the lens under test facing up and the other side facing down; the light emitted from the point light source is reflected by the lens under test after passing through the collimating lens and the first focusing lens, and then magnified by the second focusing lens to form an image. The image spot of the second focusing lens is then captured by a camera.

[0036] 2) Invert the two sides of the lens to be tested, and use the camera to collect the imaging spot of the second focusing lens according to the method in step 1);

[0037] 3) Compare the shape and / or size of imaging spot one and imaging spot two to distinguish between plane and curved surface.

[0038] In step 3), the sizes of imaging spot one and imaging spot two are compared. When imaging spot one is larger, the downward-facing side of the lens under test in step 1) is a curved surface and the other side is a flat surface; when imaging spot two is larger, the downward-facing side of the lens under test in step 2) is a curved surface and the other side is a flat surface.

[0039] Any techniques not mentioned in this invention are based on existing technologies.

[0040] The present invention provides a method for detecting the front and back surfaces of an imaging-type ultra-small curvature plano-convex or plano-concave lens. This method is simple and easy to operate, and can distinguish between curved and flat surfaces through a specific imaging method. It is highly efficient and 100% accurate. The present invention also provides a device for detecting the front and back surfaces of an imaging-type ultra-small curvature plano-convex or plano-concave lens. This device has a simple structure and is easy to use. After passing through the optical system with the specific structure of this application, an imaging spot can be obtained using a planar array camera. The size of the two spots can be used to accurately determine whether the curved surface is facing upwards or the flat surface is facing upwards. Attached Figure Description

[0041] Figure 1 This is a diagram showing the elevation of the sag.

[0042] Figure 2 The detection optical path diagram (curved surface facing the point light source) of the detection device for the front and back surfaces of the imaging type ultra-small curvature plano-convex lens or plano-concave lens in Embodiment 1 of the present invention is shown.

[0043] Figure 3 The detection optical path diagram (plane facing the point light source) of the detection device for the front and back surfaces of the imaging type ultra-small curvature plano-convex lens or plano-concave lens in Embodiment 1 of the present invention is shown.

[0044] Figure 4 The simulation results for the sample with a radius of curvature R = 900 mm in Example 1 of the present invention are shown in the left figure (the imaging spot of the curved surface facing the point light source and the imaging spot of the plane facing the point light source).

[0045] Figure 5 The simulation results for the sample with a radius of curvature R = 300 mm in Example 1 of the present invention are shown in the left figure (the imaging spot of the curved surface facing the point light source and the imaging spot of the plane facing the point light source).

[0046] Figure 6 The detection optical path diagram (curved surface facing up) of the detection device for the front and back surfaces of the imaging type ultra-small curvature plano-convex lens or plano-concave lens in Embodiment 2 of the present invention is shown.

[0047] Figure 7 The detection optical path diagram (curved surface facing down) of the detection device for the front and back surfaces of the imaging type ultra-small curvature plano-convex lens or plano-concave lens in Embodiment 2 of the present invention is shown.

[0048] Figure 8The simulation results of the sample with a curvature radius R = 900 mm in Example 2 of the present invention are shown in the left figure (the imaging spot with the curved surface facing upwards and the imaging spot with the flat surface facing upwards).

[0049] Figure 9 The simulation results of the sample with a curvature radius R = 300 mm in Example 2 of the present invention are shown in the left figure (the imaging spot with the curved surface facing upwards and the imaging spot with the flat surface facing upwards).

[0050] Figure 10 The detection optical path diagram (curved surface facing up) of the detection device for the front and back surfaces of the imaging type ultra-small curvature plano-convex lens or plano-concave lens in Embodiment 3 of the present invention is shown.

[0051] Figure 11 The detection optical path diagram (curved surface facing down) of the detection device for the front and back surfaces of the imaging type ultra-small curvature plano-convex lens or plano-concave lens in Embodiment 3 of the present invention is shown.

[0052] Figure 12 The simulation results of the sample with a curvature radius R = 900 mm in Example 3 of the present invention are shown in the left figure (the imaging spot with the curved surface facing upwards and the imaging spot with the flat surface facing upwards).

[0053] Figure 13 The simulation results of the sample with a curvature radius R = 300 mm in Example 3 of the present invention are shown in the left figure (the imaging spot with the curved surface facing upwards and the imaging spot with the flat surface facing upwards).

[0054] In the figure, 1 is a point light source, 2 is a collimating lens, 3 is a beam splitter, 4 is a reflecting mirror, 5 is the first focusing lens, 6 is the second focusing lens, 7 is an area array camera, 8 is the sample being tested, 9 is the axis of symmetry, and 10 is the sag. Detailed Implementation

[0055] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0056] Example 1

[0057] A device for detecting the front and back surfaces of an imaging-type ultra-small curvature plano-convex or plano-concave lens includes an output component, a functional component, and a receiving component; the functional component is a first focusing lens or a beam splitter; the output component includes a point light source and a collimating lens, and the receiving component includes a second focusing lens and an area array camera; the point light source, collimating lens, functional component, second focusing lens, and area array camera are arranged sequentially along the optical path propagation direction.

[0058] like Figure 2-3As shown, using the transmission imaging method, the functional components are a first focusing lens, a point light source, a collimating lens, a first focusing lens, a second focusing lens, and an area scan camera arranged sequentially in the same direction. The optical axes of the collimating lens, the first focusing lens, and the second focusing lens overlap, and the point light source and the area scan camera are both located on the optical axis.

[0059] The first focusing lens is set up to control the diameter of the light beam, so that the light beam can penetrate the sample with a relatively small aperture. At this time, the light beam can be focused to obtain a focused spot, but the diameter of the spot may be relatively small, which is not conducive to subsequent software judgment. In order to obtain a larger focused spot, a second focusing lens is added. In fact, its function is to act as a relay lens, that is, to magnify the focused spot and make the size of the imaging spot behind the second focusing lens larger, so as to facilitate image acquisition and processing.

[0060] Using the above-mentioned device, transmission imaging detection is performed, including the following steps:

[0061] 1) Place the lens to be tested (plano-convex lens) between the first focusing lens and the second focusing lens, with one side of the lens facing the point light source and the other side facing the area array camera; the light emitted from the point light source passes through the collimating lens and the first focusing lens, then passes through the lens to be tested, and is magnified by the second focusing lens to form an image. The camera then collects the image spot of the second focusing lens.

[0062] 2) Invert the two sides of the lens to be tested, and use the camera to collect the imaging spot of the second focusing lens according to the method in step 1);

[0063] 3) Compare the sizes of imaging spot one and imaging spot two. When imaging spot one is larger, the side of the lens under test facing the point light source in step 1) is a plane; when imaging spot two is larger, the side of the lens under test facing the point light source in step 2) is a plane. For example... Figure 4-5 As shown, the imaging spots have curvature radii R = 900 mm and 300 mm, respectively. The imaging spot with the curved surface facing the point light source is significantly smaller than the imaging spot with the flat surface facing the point light source. Moreover, the smaller the curvature radius, the greater the difference in spot diameter, and the easier it is to distinguish them.

[0064] Example 2

[0065] Unlike Example 1, as follows: Figure 6-7 As shown, the vertical reflection imaging method is used, with a beam splitter as the functional component. The point light source, collimating lens, and beam splitter are arranged from left to right, while the area array camera, second focusing lens, beam splitter, and reflecting mirror are arranged from top to bottom. The beam splitter is a cubic beam splitter composed of two 45° right-angled triangular prisms. The optical axis of the collimating lens forms a 45° angle with the joint of the beam splitter, the optical axis of the collimating lens is perpendicular to the reflecting surface of the reflecting mirror, and the optical axis of the second focusing lens forms a 45° angle with the joint of the beam splitter.

[0066] Using the above-mentioned device, vertical reflection imaging detection is performed, including the following steps:

[0067] 1) Place the lens to be tested (plano-convex lens) between the beam splitter and the reflecting mirror, with one side of the lens facing the beam splitter and the other side facing the reflecting mirror; the light emitted from the point source is collimated by the collimating mirror, then folded downwards by the beam splitter, passes through the lens to be tested, reaches the reflecting mirror, is reflected by the reflecting mirror, passes through the sample to be tested and the beam splitter again, and is then focused by the focusing mirror. The imaging spot of the second focusing mirror is collected by the camera.

[0068] 2) Invert the two sides of the lens to be tested, and use the camera to collect the imaging spot of the second focusing lens according to the method in step 1);

[0069] 3) Compare the sizes of imaging spot one and imaging spot two. When imaging spot one is larger, in step 1), the side of the lens under test facing the reflecting mirror is curved, and the other side is flat; when imaging spot two is larger, in step 2), the side of the lens under test facing the point reflecting mirror is curved, and the other side is flat; for example... Figure 8-9 As shown, the imaging spots have curvature radii R = 900 mm and 300 mm, respectively. The imaging spot with the curved surface facing upwards is significantly smaller than the imaging spot with the flat surface facing upwards. Furthermore, the smaller the curvature radius, the greater the difference in spot diameter, and the easier it is to distinguish. A magnifying relay mirror can be installed between the area array camera and the second focusing lens as needed.

[0070] Example 3

[0071] Unlike Example 1, as follows: Figure 10-11 As shown, the 45° reflection imaging method is used. The functional components are the first focusing lens, the collimating lens and the optical axis of the first focusing lens overlap and are both at an angle of 45° with the horizontal plane; the optical axis of the second focusing lens is symmetrical to the optical axis of the first focusing lens and intersects it; the point light source is set on the optical axis of the collimating lens, and the area array camera is set on the optical axis of the second focusing lens.

[0072] Using the above-mentioned device, a 45° reflectance imaging method for detection is performed, including the following steps:

[0073] 1) Place the lens to be tested (plano-convex lens) at the position where the optical axes of the first focusing lens and the second focusing lens intersect, with one side of the lens to be tested facing up and the other side facing down; the light emitted from the point light source is reflected by the lens to be tested after passing through the collimating lens and the first focusing lens, and then magnified by the second focusing lens to form an image. The image spot of the second focusing lens is then captured by a camera.

[0074] 2) Invert the two sides of the lens to be tested, and use the camera to collect the imaging spot of the second focusing lens according to the method in step 1);

[0075] 3) Compare the sizes of imaging spot one and imaging spot two to distinguish between plane and curved surface. When the imaging spot is large, the downward side of the lens under test in step 1) is curved surface and the upward side is plane. When the imaging spot is large, the downward side of the lens under test in step 2) is curved surface and the upward side is plane. The smaller the radius of curvature, the greater the difference in spot diameter, and the easier it is to distinguish.

Claims

1. A method for detecting the front and back surfaces of an imaging-type ultra-small curvature plano-convex lens or plano-concave lens, characterized in that: the detection device for the front and back surfaces of the imaging-type ultra-small curvature plano-convex lens or plano-concave lens comprises an emitting assembly, a functional assembly and a receiving assembly; the functional assembly is a first focusing mirror (5) or a beam splitter (3); the emitting assembly comprises a point light source (1) and a collimating mirror (2), and the receiving assembly comprises a second focusing mirror (6) and a face array camera (7); the light source, the collimating mirror (2), the functional assembly, the second focusing mirror (6) and the face array camera (7) are sequentially arranged along the direction of light propagation; the method for detecting the front and back surfaces of the imaging-type ultra-small curvature plano-convex lens or plano-concave lens realizes the differentiation between a plane and a curved surface through imaging methods, which include transmission imaging, right-angle reflection imaging and acute-angle reflection imaging; when the transmission imaging method is used, the functional assembly is the first focusing mirror (5), the point light source (1), the collimating mirror (2), the first focusing mirror (5), the second focusing mirror (6) and the face array camera (7) are sequentially arranged along the same direction, the optical axes of the collimating mirror (2), the first focusing mirror (5) and the second focusing mirror (6) are overlapped, and the point light source (1) and the face array camera (7) are both arranged on the optical axis; when the right-angle reflection imaging method is used, the functional assembly is the beam splitter (3), the point light source (1), the collimating mirror (2) and the beam splitter (3) are sequentially arranged from left to right, and the face array camera (7), the second focusing mirror (6), the beam splitter (3) and a reflecting mirror (4) are sequentially arranged from top to bottom; when the acute-angle reflection imaging method is used, the functional assembly is the first focusing mirror (5), the optical axes of the collimating mirror (2) and the first focusing mirror (5) are overlapped and form an angle of α with the horizontal plane, 0° < α < 90°; the optical axis of the second focusing mirror (6) is symmetric to the left and right of the optical axis of the first focusing mirror (5) and intersects with the optical axis of the first focusing mirror (5); the point light source (1) is arranged on the optical axis of the collimating mirror (2), and the face array camera (7) is arranged on the optical axis of the second focusing mirror (6). The acute-angle reflection imaging method is a 45-degree reflection imaging method. The transmission imaging method differentiates between a plane and a curved surface through the size of an imaging spot, the imaging spot of a curved surface facing the light source is obviously smaller than the imaging spot of the curved surface away from the light source; the right-angle reflection imaging method differentiates between a plane and a curved surface through the size of an imaging spot, the imaging spot of a plane facing the beam splitter is obviously larger than the imaging spot of a curved surface facing the beam splitter; the acute-angle reflection imaging method differentiates between a plane and a curved surface through the size of an imaging spot, the imaging spot of a curved surface facing down is obviously larger than the imaging spot of the curved surface facing up. When the right-angle reflection imaging method is used, the beam splitter (3) is a cubic beam splitter made by splicing two 45-degree right-angle prisms, the optical axis of the collimating mirror (2) forms a 45-degree angle with the splicing position of the beam splitter (3), the optical axis of the collimating mirror (2) is perpendicular to the reflecting surface of the reflecting mirror (4), and the optical axis of the second focusing mirror (6) forms a 45-degree angle with the splicing position of the beam splitter (3); an amplification relay lens is arranged between the second focusing mirror (6) and the face array camera (7). When the transmission imaging method is used, the detection method comprises the following steps: ​ ​ ​ ​ ​ ​ ​ 2. The detection method of claim 1, wherein: ​ 3. The detection method according to claim 1 or 2, characterized in that: ​ 4. The detection method according to claim 1 or 2, characterized in that: ​ 5. The detection method according to claim 1 or 2, characterized in that: ​ 1) Place the lens to be measured between the first focusing mirror (5) and the second focusing mirror (6), one side of the lens to be measured faces the point light source (1), and the other side faces the area array camera (7); the light emitted by the point light source (1) passes through the collimating mirror (2) and the first focusing mirror (5), then passes through the lens to be measured, and then is enlarged and imaged by the second focusing mirror (6), and then the imaging spot one of the second focusing mirror (6) is collected by the camera; 2) Turn over the two sides of the lens to be measured, and collect the imaging spot two of the second focusing mirror (6) by the method of step 1); 3) Compare the sizes of the imaging spot one and the imaging spot two, when the imaging spot one is large, the side of the lens to be measured facing the point light source (1) in step 1) is a plane, and the other side is a curved surface; when the imaging spot two is large, the side of the lens to be measured facing the point light source (1) in step 2) is a plane, and the other side is a curved surface; When the right-angle reflection imaging method is used, the detection method comprises the following steps: 1) Place the lens to be measured between the light splitting mirror (3) and the reflecting mirror (4), one side of the lens to be measured faces the light splitting mirror (3), and the other side faces the reflecting mirror (4); the light emitted by the point light source (1) is collimated by the collimating mirror (2), then is folded downward by the light splitting mirror (3), then passes through the lens to be measured to reach the reflecting mirror (4), then is reflected by the reflecting mirror (4) again, then passes through the measured sample (8) and the light splitting mirror (3) again, then is focused by the focusing mirror, and then the imaging spot one of the second focusing mirror (6) is collected by the camera; 2) Turn over the two sides of the lens to be measured, and collect the imaging spot two of the second focusing mirror (6) by the method of step 1); 3) Compare the sizes of the imaging spot one and the imaging spot two, when the imaging spot one is large, the side of the lens to be measured facing the reflecting mirror (4) in step 1) is a curved surface, and the other side is a plane; when the imaging spot two is large, the side of the lens to be measured facing the point reflecting mirror (4) in step 2) is a curved surface, and the other side is a plane; When the acute-angle reflection imaging method is used, the detection method comprises the following steps: 1) Place the lens to be measured at the position where the optical axes of the first focusing mirror (5) and the second focusing mirror (6) intersect, one side of the lens to be measured faces upward, and the other side faces downward; the light emitted by the point light source (1) passes through the collimating mirror (2) and the first focusing mirror (5), is reflected by the lens to be measured, then is enlarged and imaged by the second focusing mirror (6), and then the imaging spot one of the second focusing mirror (6) is collected by the camera; 2) Turn over the two sides of the lens to be measured, and collect the imaging spot two of the second focusing mirror (6) by the method of step 1); 3) Compare the shapes and / or sizes of the imaging spot one and the imaging spot two to distinguish the plane and the curved surface.

Images