Variable magnification reflection type eccentricity meter using non-rotation measurement to measure lens eccentricity

Abstract

The utility model discloses a kind of non-rotating measurement measured lens eccentricity's variable-magnification reflection type eccentricity instrument, including fixed lens barrel;Positive lens group, the positive lens group is arranged in one end of the fixed lens barrel;CCD camera, the CCD camera is arranged in the other end of the fixed lens barrel;Spectroscopic prism, the spectroscopic prism is arranged in the fixed lens barrel;Vertical lens barrel, the vertical lens barrel is arranged in the lateral wall of the fixed lens barrel;Light source, the light source is arranged in the vertical lens barrel;Crosshair scale, the crosshair scale is located between the light source and the spectroscopic prism;Negative lens group is slidably connected in the fixed lens barrel along axial direction;The spectroscopic prism includes two three-prism with isosceles right triangle cross section shape. The focal point position of light line is changed by sliding, the image position of crosshair scale received on CCD camera occurs, without rotating measured lens, and also improve detection efficiency.

Description

Technical Field

[0001] This utility model belongs to the technical field of reflective eccentricity meter, and particularly relates to a variable magnification reflective eccentricity meter that uses non-rotation to measure the eccentricity of the lens under test. Background Technology

[0002] A reflective eccentricity meter is a commonly used instrument for measuring the eccentricity of lenses or other optical components. Eccentricity refers to the misalignment of the geometric central axis of an optical component with its optical principal axis. The working principle of eccentricity detection is as follows: light is shone onto the surface of the lens being tested (generally referring to lenses, cemented lenses, and complete lens assemblies), while the lens is rotated and the reflection of light from the surface is observed to determine whether the lens is eccentric.

[0003] Chinese patent document CN222343498U discloses an automatic optical lens eccentricity detection device, including a frame, a detection platform and an eccentricity meter mounted on the frame, with the eccentricity meter located directly above the detection platform. The detection platform includes a centering clamp driven to rotate by an electric turntable. A feeding device, a robotic arm and a conveying device are arranged beside the frame. The feeding device includes a vertically placed cylindrical hopper with partitions separating adjacent lenses. A dropping platform is located below the cylindrical hopper, with a gap between the dropping platform and the hopper. A blower is located beside the dropping platform, with its outlet facing the gap between the dropping platform and the hopper. The device automatically drops the lenses by gravity, one by one. The centering clamp is designed to prevent damage to the optical lenses due to excessive force. It can hold optical lenses of different sizes and ultimately achieves separate conveying of qualified and unqualified optical lenses.

[0004] As described in the aforementioned patent solution, the lens placed on the testing platform needs to rotate with the platform to complete the lens eccentricity detection process. On one hand, the lens is detachably placed on the testing platform, which may result in gaps. Therefore, the rotation of the testing platform must be as smooth as possible to ensure testing accuracy, but this leads to low measurement efficiency. On the other hand, some lenses with special structures are restricted from rotation, which also greatly inconveniences eccentricity measurement. Therefore, the aforementioned patent solution suffers from narrow applicability and low efficiency in practical applications. Utility Model Content

[0005] To overcome the technical problems of existing technologies that require lens rotation for eccentricity detection, resulting in low detection efficiency and inapplicability to non-rotating lenses, this invention aims to provide a variable magnification reflective eccentricity meter for measuring the eccentricity of a lens without rotation. This is achieved by setting up a fixed lens barrel and a vertical lens barrel that are perpendicular to each other, with a beam-splitting prism composed of two prisms at their junction. A negative focal length lens group is slidably positioned within the fixed lens barrel. By moving the negative focal length lens group to change the focal point position of the light rays, the tilt and offset between the center of the lens and the optical axis can be determined. This method not only eliminates the need to rotate the lens but also improves detection efficiency.

[0006] To achieve the above objectives, this utility model employs the following technical solution: a variable magnification reflective eccentricity meter for measuring the eccentricity of a lens using non-rotation measurement, comprising: a fixed lens barrel; a positive focal lens group disposed at one end of the fixed lens barrel; a CCD camera disposed at the other end of the fixed lens barrel; a beam splitter disposed within the fixed lens barrel and close to the CCD camera; a vertical lens barrel disposed on the side wall of the fixed lens barrel, perpendicular to the fixed lens barrel and directly opposite the beam splitter; and a light source. The light source is disposed within the vertical lens barrel; a cross reticle is disposed within the vertical lens barrel and located between the light source and the beam splitter; wherein, a negative focal lens group is slidably connected axially between the positive focal lens group and the beam splitter within the fixed lens barrel, the negative focal lens group being a cemented lens with a negative focal length used to compensate for aberrations; the beam splitter includes two triangular prisms with cross-sectional shapes of isosceles right triangles; the two right-angled sides of one triangular prism are respectively opposite to the cross reticle and the negative focal lens group, and the hypotenuse is close to the hypotenuse of the other triangular prism.

[0007] Furthermore, a sliding lens barrel is slidably connected within the fixed lens barrel along the axial direction; the negative focal lens group is disposed at one end of the sliding lens barrel facing the positive focal lens group; and a driving part for driving the sliding lens barrel to slide is provided on the outer wall of the fixed lens barrel.

[0008] Optionally, the outer wall of the fixed lens barrel is provided with a through groove along the axial direction; the sliding lens barrel is provided with an extension rod that is slidably connected to the through groove.

[0009] Optionally, the extension rod is threaded onto the sliding lens barrel; the extension rod may also be locked onto the fixed lens barrel.

[0010] Optionally, the driving unit is a linear motion module.

[0011] Furthermore, the positive focal length lens group includes two sets of cemented lenses with positive focal lengths arranged along the axial direction of the fixed lens barrel; the cemented lenses with positive focal lengths include a convex lens and a concave lens.

[0012] Specifically, in the positive focal lens group, two concave lenses are located between two convex lenses; the end of the convex lens away from the negative focal lens group is curved; and the end of the convex lens close to the negative focal lens group is flat.

[0013] Furthermore, the negative focal length cemented lens includes a convex lens and a concave lens; wherein the convex lens is located on the side closer to the positive focal lens group, and the end of the convex lens closer to the positive focal lens group is a plane.

[0014] Furthermore, the light source includes a light-emitting element arranged sequentially along the axial direction of the vertical lens barrel and two sets of uniform light-emitting lens groups.

[0015] Furthermore, a connecting seat is provided at the end of the fixed lens barrel away from the focal lens group; the beam splitter is disposed inside the connecting seat; the CCD camera is disposed at the end of the connecting seat away from the fixed lens barrel; and the sliding lens barrel is disposed on the side wall of the connecting seat.

[0016] Compared to existing technologies, the advantages of this invention are as follows: This invention uses a sliding negative focal lens group to converge light rays to the center of the lens under test. Sliding the lens to change the focal point position allows for changes in the image position received by the crosshair reticle on the CCD camera, accurately locating the offset and tilt of the lens's center of gravity relative to the optical axis. This not only eliminates the need to rotate the lens under test for eccentricity detection but also improves detection efficiency. Furthermore, it solves the problem that some lenses, due to their unique structure, cannot be rotated for eccentricity measurement. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the lens arrangement of this utility model;

[0019] Figure 3 This is a schematic diagram of the optical path of this utility model;

[0020] Figure 4 This is a schematic diagram of the concave lens detection method of this utility model;

[0021] Figure 5 This is a schematic diagram of the convex lens detection method of this utility model.

[0022] In the diagram: 1. Positive focal lens group; 2. Negative focal lens group; 3. Beam splitter prism; 4. Cross reticle; 5. Beam homogenizing lens group; 6. Light source; 7. CCD camera; 8. Optical axis; 9. Optical focal point; 10. Concave lens under test; 11. Convex lens under test; 12. Center of concave lens A; 13. Center of concave lens B; 14. Center of convex lens C; 15. Center of convex lens D; 16. Fixed lens barrel; 161. Through slot; 17. Sliding lens barrel; 18. Drive unit; 19. Vertical lens barrel; 20. Extension rod; 21. Connecting seat. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0024] In the description of this utility model, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this utility model.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In this description of the utility model, "a number" means two or more, unless otherwise explicitly specified.

[0026] In this utility model, unless otherwise explicitly specified and limited, terms such as "set" and "install" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can also refer to a mechanical connection; they can refer to a direct connection or a connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] See Figures 1-5A variable magnification reflective eccentricity measuring instrument for measuring the eccentricity of a lens under test using non-rotation method includes a connecting base 21, a fixed lens barrel 16 disposed at one end of the connecting base 21, a CCD camera 7 disposed at the other end of the connecting base 21, a vertical lens barrel 19 disposed on the side wall of the connecting base 21, and a beam splitter prism 3 disposed within the connecting base 21.

[0028] A positive focal lens group 1 is provided at one end of the fixed lens barrel 16 away from the connecting seat 21; a sliding lens barrel 17 is slidably connected along the axial direction inside the fixed lens barrel 16; a negative focal lens group 2 is provided at one end of the sliding lens barrel 17 away from the connecting seat 21; the positive focal lens group 1, the negative focal lens group 2, and the CCD camera 7 are coaxially arranged.

[0029] The outer wall of the fixed lens barrel 16 is provided with a driving part 18 for driving the sliding lens barrel 17 to slide; the driving part 18 is a linear motion module, which can be an electric push rod or a lead screw module, etc.

[0030] The outer wall of the fixed lens barrel 16 is provided with a through groove 161 along the axial direction; the sliding lens barrel 17 is provided with an extension rod 20 that is slidably connected to the through groove 161; the extension rod 20 is threadedly connected to the sliding lens barrel 17; the extension rod 20 can be selectively locked to the fixed lens barrel 16.

[0031] The positive focal lens group 1 includes two sets of cemented lenses with positive focal lengths arranged along the axis of the fixed lens barrel 16; each cemented lens with positive focal lengths includes a convex lens and a concave lens; wherein, the two concave lenses are located between the two convex lenses; the end of the convex lens away from the negative focal lens group 2 is curved; the end of the convex lens close to the negative focal lens group 2 is flat.

[0032] The negative focal length lens group 2 is a cemented lens with a negative focal length used to compensate for aberrations; the negative focal length cemented lens includes a convex lens and a concave lens; the convex lens is located on the side close to the positive focal length lens group 1, and the end of the convex lens close to the positive focal length lens group 1 is a plane.

[0033] A light source is provided at one end of the vertical lens barrel 19 away from the connecting seat 21; a cross reticle 4 is provided inside the vertical lens barrel 19 between the light source and the connecting seat 21; the light source includes a light-emitting body 6 arranged sequentially along the axial direction of the vertical lens barrel 19 and two sets of uniform light lens groups 5.

[0034] The beam splitter 3 includes two prisms with cross-sectional shapes of isosceles right triangles; the two right-angled sides of one prism are directly opposite the cross reticle 4 and the negative focal lens group 2, respectively, and the hypotenuse is close to the hypotenuse of the other prism.

[0035] The working principle is as follows: Light emitted by the light source 6 passes through two homogenizing lens groups 5 and illuminates the crosshair reticle 4. The image of the crosshair reticle 4 passes through the beam splitter prism 3 and enters the negative focal lens group 2. After the light is diverged by the negative focal lens group 2, it passes through the positive focal lens group 1, which re-converges the light to the optical focal point 9. Since the negative focal lens group 2 can move left and right, the focal length of the optical system changes accordingly. Therefore, the position of the optical focal point 9 also changes with the change in focal length. However, the position of the optical focal point 9 will only move left and right along the optical axis 8 and will not deviate from the trajectory of the optical axis 8.

[0036] At this point, we move the negative focal lens group 2 to converge the optical focal point 9 to the position of the concave lens center A12 of the concave lens 10 under test. Now, the concave lens center A12 and the optical focal point 9 coincide. Based on the principle that a straight line passing through the center of the sphere will return along its original path upon encountering the surface of the sphere, the light will also be reflected back along its original path, passing through the positive focal lens group 1 and the negative focal lens group 2, and reaching the position of the beam splitter 3. The light will then pass through the beam splitter 3 and converge onto the chip surface of the CCD camera 7, forming a crosshair reticle image. When the position of the concave lens center A12 of the concave lens 10 under test changes, the position of the crosshair image formed on the chip surface of the CCD camera 7 also changes. This allows us to accurately determine the offset of the concave lens center A12 relative to the optical axis 8.

[0037] Using the same method, change the position of the negative focal lens group 2, and find the concave lens center B13 of the concave lens 10 being tested, and the convex lens center C14 and convex lens center D15 of the convex lens 11 being tested. At this time, the offset of the center position from the optical axis 8 can be calculated from these four center images. Then, the tilt and offset between the optical axis 8 of the line connecting the concave lens center A12 and the concave lens center B13 and the optical axis 8 of the line connecting the convex lens center C14 and the convex lens center D15 can be calculated.

[0038] The above description is only a specific embodiment of the present utility model, but the technical features of the present utility model are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present utility model are covered by the patent scope of the present utility model.

Claims

1. A variable magnification reflective eccentricity meter for measuring the eccentricity of a lens under test using non-rotation measurement, characterized in that: The system includes a fixed lens barrel; a positive focusing lens group disposed at one end of the fixed lens barrel; a CCD camera disposed at the other end of the fixed lens barrel; a beam splitter disposed inside the fixed lens barrel and close to the CCD camera; a vertical lens barrel disposed on the side wall of the fixed lens barrel, perpendicular to the fixed lens barrel and directly opposite the beam splitter; a light source disposed inside the vertical lens barrel; and a crosshair reticle. The reticle is disposed within the vertical lens barrel and located between the light source and the beam splitter; wherein, a negative focal lens group is slidably connected axially within the fixed lens barrel between the positive focal lens group and the beam splitter, the negative focal lens group being a cemented lens with a negative focal length used to compensate for aberrations; the beam splitter includes two triangular prisms with cross-sectional shapes of isosceles right triangles; the two right-angled sides of one triangular prism are respectively opposite to the cross reticle and the negative focal lens group, and the hypotenuse is close to the hypotenuse of the other triangular prism.

2. The reflective eccentricity as described in claim 1, characterized in that: A sliding lens barrel is slidably connected axially inside the fixed lens barrel; the negative focal lens group is disposed at one end of the sliding lens barrel facing the positive focal lens group; a driving part for driving the sliding lens barrel to slide is provided on the outer wall of the fixed lens barrel.

3. The reflective eccentricity as described in claim 2, characterized in that: The outer wall of the fixed lens barrel is provided with a through groove along the axial direction; the sliding lens barrel is provided with an extension rod that is slidably connected to the through groove.

4. The reflective eccentricity as described in claim 3, characterized in that: The extension rod is threaded onto the sliding lens barrel; the extension rod can be optionally locked onto the fixed lens barrel.

5. The reflective eccentricity as described in claim 2, characterized in that: The drive unit is a linear motion module.

6. The reflective eccentricity as described in any one of claims 1-5, characterized in that: The positive focal length lens group includes two sets of cemented lenses with positive focal lengths arranged along the axial direction of the fixed lens barrel; the cemented lenses with positive focal lengths include a convex lens and a concave lens.

7. The reflective eccentricity as described in claim 6, characterized in that: In the positive focal lens group, two concave lenses are located between two convex lenses; the end of the convex lens away from the negative focal lens group is curved; the end of the convex lens close to the negative focal lens group is flat.

8. The reflective eccentricity as described in any one of claims 1-5, characterized in that: The negative focal length cemented lens includes a convex lens and a concave lens; wherein the convex lens is located on the side closer to the positive focal lens group, and the end of the convex lens closer to the positive focal lens group is a plane.

9. The reflective eccentricity as described in any one of claims 1-5, characterized in that: The light source includes a light-emitting element arranged sequentially along the axial direction of the vertical lens barrel and two sets of uniform light lenses.

10. The reflective eccentricity as described in any one of claims 2-5, characterized in that: A connecting seat is provided at the end of the fixed lens barrel away from the positive focusing lens group; the beam splitter is disposed inside the connecting seat; the CCD camera is disposed at the end of the connecting seat away from the fixed lens barrel; and the sliding lens barrel is disposed on the side wall of the connecting seat.

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