High-precision large-depth-of-field projection diameter measuring device

Abstract

The invention discloses a high-precision large-depth-of-field projection diameter measuring device. The high-precision large-depth-of-field projection diameter measuring device comprises a telecentric lens module and a telecentric illumination module, the telecentric lens module comprises an area array telecentric lens module received by the area array image sensor and a linear array telecentric lens module received by the linear array image sensor, and comprises a first lens to a twelfth lens, a flat spectroscope, a first reflector, the area array image sensor and the linear array image sensor; the telecentric lighting module comprises thirteenth to sixteenth lenses, a lighting source, a light bar, a second reflector and a third reflector. According to the high-precision large-depth-of-field projection diameter measuring device, a mode that the area array telecentric lens module and the linear array telecentric lens module work cooperatively is adopted, so that the detection efficiency is improved; the lens is long in working distance and can be used for detecting large-size workpieces; meanwhile, the structure is simple and compact, assembling difficulty is low, and practicability is high.

Description

Technical Field

[0001] The present application relates to the field of optical measurement technology, and in particular to a high-precision large-depth-of-field projection diameter measurement device. Background Art

[0002] The projection image measurement system is an optical sensor technology widely used in the industrial field. The transmitter emits LED light to illuminate the object to be measured, and the receiver captures the projection formed after the light is blocked by the object. By analyzing this projected image, the size, defects and position of the object can be measured quickly and accurately.

[0003] Telecentric lens module and telecentric lighting module are the core components of this measurement system. Their telecentricity and aberration directly affect the measurement accuracy, while the greater depth of field determines the measurement range that the system can cover.

[0004] In industrial applications, different measurement scenarios require different work efficiencies, especially when batch testing large workpieces, the measurement system needs to have high work efficiency and miniaturized structural design. However, at present, there is little technical accumulation in the research and development of such systems in China, and the equipment is still insufficient in measurement efficiency and accuracy, and is not suitable for large-scale batch testing on assembly lines. Therefore, developing a high-precision and high-efficiency domestic projection measurement system to meet industrial needs is one of the current problems that need to be solved urgently. Summary of the invention

[0005] Based on the above background, the embodiment of the present application proposes a high-precision large depth of field projection diameter measurement device, which improves the measurement efficiency of the system through a telecentric illumination module and a telecentric lens module combining a planar array and a linear array. The system not only has a long working distance and is suitable for the detection of large-sized workpieces, but also greatly improves the efficiency of industrial measurement, and enhances the practicality and feasibility of industrial applications.

[0006] According to an embodiment of the present application, a high-precision large-depth-of-field projection diameter measuring device is provided, comprising a telecentric lighting module and a telecentric lens module, wherein the telecentric lighting module and the telecentric lens module are arranged opposite to each other, and a light beam emitted by a light source is shaped into a telecentric lighting beam by the telecentric lighting module, and the light beam is blocked by a sample to be measured placed between the telecentric lighting module and the telecentric lens module and then incident from the telecentric lens module, and is imaged onto an image sensor through the telecentric lens, forming a shadow image of the sample to be measured on the image sensor; The telecentric lens module includes a surface array telecentric lens module and a linear array telecentric lens module, wherein: The area array telecentric lens module comprises a first lens, a second lens, a third lens, a fourth lens, a flat beam splitter, a fifth lens, a sixth lens, a seventh lens, an eighth lens and an area array image sensor which are sequentially arranged from the object side to the image side, wherein the first lens and the second lens form a first closely connected double-cemented lens, the third lens and the fourth lens form a closely connected second double-cemented lens, the fifth lens and the sixth lens form a closely connected third double-cemented lens, and the seventh lens and the eighth lens form a closely connected fourth double-cemented lens; The linear array telecentric lens module comprises a first reflector, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a linear array image sensor which are arranged in sequence from the object side to the image side, the ninth lens and the tenth lens form a fifth close-contact double-cemented lens, and the eleventh lens and the twelfth lens form a sixth close-contact double-cemented lens; The telecentric illumination beam is blocked by the sample to be tested and then incident on the first lens. After being transmitted and reflected by the flat beam splitter, it is emitted from the eighth lens and the twelfth lens respectively, and the shadow image of the sample to be tested is obtained on the area array image sensor and the line array image sensor respectively.

[0007] The technical solution provided by the embodiments of the present application may have the following beneficial effects: It can be seen from the above embodiments that the present application has a very large depth of field range, thereby achieving a larger high-precision measurement range. At the same time, the system has a compact structure and a small volume, and has high measurement efficiency, and is suitable for various industrial environments.

[0008] The high-precision large-depth-of-field projection diameter measuring device includes a telecentric illumination module and a telecentric lens module. The telecentric illumination module and the telecentric lens module are arranged opposite to each other. The object to be measured is placed at the working distance. The light beam emitted by the light source is shaped into a telecentric illumination beam by the telecentric illumination module. The light beam is blocked by the sample to be measured placed between the telecentric illumination module and the telecentric lens module and then enters the telecentric lens module. It can be imaged onto the area array image sensor through the area array telecentric lens or onto the linear array image sensor through the linear array telecentric lens, and the shadow image of the sample to be measured is formed on the two image sensors respectively. The system realizes the large-scale and high-precision projection image measurement of the object to be measured by integrating telecentric illumination and telecentric lens; and realizes the organic combination of high-efficiency and high-precision measurement by combining the linear array telecentric lens module with the area array telecentric lens module. During the measurement process, the system first uses the linear array telecentric lens module for rapid detection to improve the overall measurement speed; if an abnormality is detected, it can switch to the area array telecentric lens module to further improve the accuracy and achieve precise measurement.

[0009] This system not only greatly improves the detection efficiency while ensuring the measurement accuracy, but also has the advantage of compact size, making it suitable for various industrial environments and highly practical.

[0010] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0012] Figure 1 1 is a front schematic diagram of a high-precision large-depth-of-field projection diameter measuring device provided in an embodiment of the present invention; Figure 2 It is a side schematic diagram of a high-precision large-depth-of-field projection diameter measuring device provided in an embodiment of the present invention; Figure 3 is an optical structure diagram of an area array telecentric lens module provided in an embodiment of the present invention; Figure 4 is an optical structure diagram of a linear array telecentric lens module provided in an embodiment of the present invention; Figure 5 is a front mechanical structure diagram of a telecentric lens module provided in an embodiment of the present invention; Figure 6 is a side view of the mechanical structure of a telecentric lens module provided in an embodiment of the present invention; Figure 7 is an optical structure diagram of a telecentric illumination module provided in an embodiment of the present invention; Figure 8 is a mechanical structure diagram of a telecentric illumination module provided in an embodiment of the present invention; Fig. 9 is a point diagram of the area array telecentric lens module provided in an embodiment of the present invention under different fields of view at working distances; Fig.10 is a point diagram of the area array telecentric lens module provided in an embodiment of the present invention under different fields of view at a working distance of -5 mm; Fig.11 is a point diagram of the area array telecentric lens module provided in an embodiment of the present invention under different fields of view at a working distance of +5 mm; Fig.12 is an MTF diagram of the area array telecentric lens module provided in an embodiment of the present invention; Fig.13 is a CRA diagram of the area array telecentric lens module provided in an embodiment of the present invention; Fig.14 is a distortion diagram of the area array telecentric lens module provided in an embodiment of the present invention; Fig.15 is a point diagram of a linear array telecentric lens module provided in an embodiment of the present invention at different fields of view at working distances; Fig.16is a point diagram of a linear array telecentric lens module provided in an embodiment of the present invention at different fields of view at a working distance of -5 mm; Fig.17 is a point diagram of the linear array telecentric lens module provided in an embodiment of the present invention under different fields of view at a working distance of +5 mm; Fig.18 is an MTF diagram of the linear array telecentric lens module provided in an embodiment of the present invention; Fig.19 is a CRA diagram of a linear array telecentric lens module provided in an embodiment of the present invention; Fig. 20 is a distortion diagram of a linear array telecentric lens module provided in an embodiment of the present invention; The reference numerals in the figures are: 10. Telecentric lens module; 20. Sample to be tested; 30. Telecentric lighting module; L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; L7, seventh lens; L8, eighth lens; L9, ninth lens; L10, tenth lens; L11, eleventh lens; L12, twelfth lens; L13, thirteenth lens; L14, fourteenth lens; L15, fifteenth lens; L16, sixteenth lens; I1, flat beam splitter; I2, first reflector; I3, second reflector; I4, third reflector; I5, first inner lens barrel; I6, second inner lens barrel; I7, third inner lens barrel; I8, fourth inner lens barrel; I9, first protective glass; I10, second protective glass; I11, telecentric lens base; I12, telecentric lighting base; I13, area array image sensor; I14, line array image sensor; I15, lighting source; I16, light rod. DETAILED DESCRIPTION

[0013] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0014] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0015] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0016] Reference Figure 1-Figure 4 As shown, an embodiment of the present invention provides a high-precision large-depth-of-field projection diameter measuring device, which includes a telecentric lens module 10 and a telecentric lighting module 30. The telecentric lighting module 30 is arranged opposite to the telecentric lens module 10, and a sample 20 to be measured is placed at a working distance. The light beam emitted by the light source is shaped into a telecentric lighting beam by the telecentric lighting module 30. The light beam is blocked by the sample 20 to be measured placed between the telecentric lighting module 30 and the telecentric lens module 10 and then incident from the telecentric lens module 10. The light beam is imaged onto an image sensor through the telecentric lens, and a shadow image of the sample to be measured is formed on the image sensor. The telecentric lens module includes an area array telecentric lens module and a linear array telecentric lens module; the area array telecentric lens module includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a flat beam splitter I1, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and an area array image sensor I13, which are arranged in sequence from the object side to the image side; the first lens L1 and the second lens L2 form a first closely connected double-cemented lens, the third lens L3 and the fourth lens L4 form a second closely connected double-cemented lens, the fifth lens L5 and the sixth lens L6 form a third closely connected double-cemented lens, and the seventh lens L7 and the eighth lens L8 form a fourth closely connected double-cemented lens. The linear array telecentric lens module includes a first reflector I2, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12 and a linear array image sensor I14 arranged in sequence from the object side to the image side, wherein the ninth lens L9 and the tenth lens L10 form a fifth close-contact double-cemented lens, and the eleventh lens L11 and the twelfth lens L12 form a sixth close-contact double-cemented lens. After being blocked by the sample to be tested, the telecentric illumination beam is incident from the first lens L1, and after being transmitted and reflected by the flat beam splitter I1, it is emitted from the eighth lens L8 and the twelfth lens L12 respectively, and a shadow image of the sample to be tested is obtained on the area array image sensor I13 and the linear array image sensor I14.

[0017] It can be seen from the above embodiments that the present application has a very large depth of field range, thereby achieving a larger high-precision measurement range. At the same time, the system has a compact structure and a small volume, and has high measurement efficiency, and is suitable for various industrial environments.

[0018] The high-precision large-depth-of-field projection diameter measuring device includes a telecentric illumination module and a telecentric lens module. The telecentric illumination module and the telecentric lens module are arranged opposite to each other. The object to be measured is placed at the working distance. The light beam emitted by the light source is shaped into a telecentric illumination beam by the telecentric illumination module. The light beam is blocked by the sample to be measured placed between the telecentric illumination module and the telecentric lens module and then enters the telecentric lens module. It can be imaged onto the area array image sensor through the area array telecentric lens or onto the linear array image sensor through the linear array telecentric lens, and the shadow image of the sample to be measured is formed on the two image sensors respectively. The system realizes the large-scale and high-precision projection image measurement of the object to be measured by integrating telecentric illumination and telecentric lens; and realizes the organic combination of high-efficiency and high-precision measurement by combining the linear array telecentric lens module with the area array telecentric lens module. During the measurement process, the system first uses the linear array telecentric lens module for rapid detection to improve the overall measurement speed; if an abnormality is detected, it can switch to the area array telecentric lens module to further improve the accuracy and achieve precise measurement.

[0019] This system not only greatly improves the detection efficiency while ensuring the measurement accuracy, but also has the advantage of a compact volume, is applicable to various industrial environments, and has strong practicability.

[0020] In one embodiment, the first lens L1 in the telecentric lens module is a positive focal length lens, the incident surface is convex, and the exit surface is convex; the second lens L2 is a positive focal length lens, the incident surface is concave, and the exit surface is convex; the third lens L3 is a positive focal length lens, the incident surface is convex, and the exit surface is convex; the fourth lens L4 is a negative focal length lens, the incident surface is concave, and the exit surface is concave; the fifth lens L5 is a negative focal length lens, the incident surface is concave, and the exit surface is concave; the sixth lens L6 is a positive focal length lens, the incident surface is convex, and the exit surface is convex; the seventh lens L7 is a positive focal length lens, the incident surface is convex, and the exit surface is convex; the eighth lens L8 is a negative focal length lens, the incident surface is concave, and the exit surface is flat; the ninth lens L9 is a negative focal length lens, the incident surface is concave, and the exit surface is concave; the tenth lens L10 is a positive focal length lens, the incident surface is convex, and the exit surface is convex; the eleventh lens L11 is a positive focal length lens, the incident surface is convex, and the exit surface is convex; the twelfth lens L12 is a negative focal length lens, the incident surface is concave, and the exit surface is convex. Through the reasonable combination of positive focal length lenses and negative focal length lenses, the aberration is greatly reduced and the measurement accuracy is improved.

[0021] In one embodiment, the glass material of the first lens L1 in the telecentric lens module: 1.60 < n < 1.80, 30 < Vd < 50; the glass material of the second lens L2: 1.60 < n < 1.80, 20 < Vd < 40; the glass material of the third lens L3: 1.60 < n < 1.80, 30 < Vd < 50; the glass material of the fourth lens L4: 1.70 < n < 1.90, 15 < Vd < 35; the glass material of the fifth lens L5: 1.65 < n < 1.85, 20 < Vd < 40; the glass material of the sixth lens L6: 1.60 < n < 1.80, 30 < Vd < 50; the glass material of the seventh lens L7: 1.60 < n < 1.80, 40 < Vd < 60; the glass material of the eighth lens L8: 1.60 < n < 1.80, 25 < Vd < 45; the glass material of the ninth lens L9: 1.70 < n < 1.90, 15 < Vd < 35; the glass material of the tenth lens L10: 1.55 < n < 1.75, 40 < Vd < 60; the glass material of the eleventh lens L11: 1.60 < n < 1.80, 25 < Vd < 45; the glass material of the twelfth lens L12: 1.50 < n < 1.70, 40 < Vd < 60; where n is the refractive index and Vd is the Abbe number. By reasonably selecting the glass materials, the chromatic aberration and aberration of the system are greatly reduced, and the measurement accuracy is improved.

[0022] In one embodiment, in the telecentric lens module, the distance between the first lens L1 and the second lens L2 is 0 mm, the distance between the second lens L2 and the third lens L3 is 0 mm, the distance between the third lens L3 and the fourth lens L4 is 0 mm, the distance between the fourth lens L4 and the fifth lens L5 is 30-40 mm, the distance between the fifth lens L5 and the sixth lens L6 is 0 mm, the distance between the sixth lens L6 and the seventh lens L7 is 0 mm, the distance between the seventh lens L7 and the eighth lens L8 is 0 mm, and the distance between the eighth lens L8 and the area array image sensor I13 is 10-20 mm; the distance between the fourth lens L4 and the ninth lens L9 is 40-50 mm, the distance between the ninth lens L9 and the tenth lens L10 is 0 mm, the distance between the tenth lens L10 and the eleventh lens L11 is 0 mm, the distance between the eleventh lens L11 and the twelfth lens L12 is 0 mm, and the distance between the twelfth lens L12 and the linear array image sensor I14 is 20-30 mm, so that the overall structure of the lens is compact.

[0023] In one embodiment, Table 1 shows the parameters of the telecentric lens module. The working distance of this embodiment is 90 mm. At the same time, due to the use of a telecentric lens structure, a depth of field of ±5 mm can be guaranteed. Figure 9-11 The spot diagrams of the telecentric lens at working distances of 90mm, 85mm, and 95mm are shown in the attached figure. Figure 15-17 The spot diagrams of the linear telecentric lens at working distances of 90mm, 85mm, and 95mm are shown below. The aberrations are corrected within a large depth of field range of 90±5mm, so that the spot diagrams are close to the diffraction limit, which can ensure high-precision measurement within a large depth of field range. Fig.12 This is the MTF function diagram of the telecentric lens in the 525nm band. Fig.18 The MTF function diagram of the linear array telecentric lens in the 525nm band, where the MTF of each field of view is close to the diffraction limit, it can be seen that the optical resolution of the telecentric lens is relatively high. Fig.13 is the incident angle CRA curve of the telecentric lens on the image plane in the telecentric lens, attached Fig.19 The CRA curve of the incident angle of the linear array telecentric lens on the image plane. The incident angle is close to 0° at different image heights, which can reduce energy loss and reduce the distortion of the image on the image sensor. Fig.14 is the distortion curve of the telecentric lens in the telecentric lens, and Fig. 20 This is the distortion curve of the linear array telecentric lens. The maximum field of view distortion is kept within 0.1%, the full field of view distortion is less than 0.1%, and the image distortion is small.

[0024] Table 1 Telecentric lens module parameters: surface Radius of curvature (unit / mm) Semi-diameter (unit / mm) The first lens L1 incident surface 184 20 The first lens L1 exit surface -43.5 20 The second lens L2 incident surface -43.5 20 The second lens L2 exit surface -121.7 20 The incident surface of the third lens L3 44.5 20 The third lens L3 exit surface -115.5 20 The incident surface of the fourth lens L4 -115.5 20 The fourth lens L4 exit surface 77.2 20 Fifth lens L5 incident surface -44.9 7 Fifth lens L5 exit surface 15 7 Incident surface of the sixth lens L6 15 7 The sixth lens L6 exit surface -15 7 Entrance surface of the seventh lens L7 30.6 7 The seventh lens L7 exit surface -12 7 Entrance surface of the eighth lens L8 -12 7 The eighth lens L8 exit surface unlimited 7 The incident surface of the ninth lens L9 -114 10 The ninth lens L9 exit surface 27.4 10 Entrance surface of the tenth lens L10 27.4 10 The exit surface of the tenth lens L10 -25.1 10 The incident surface of the eleventh lens L11 68.1 10 The eleventh lens L11 has an exit surface -18.1 10 The incident surface of the twelfth lens L12 -18.1 10 The twelfth lens L12 exit surface -204.9 10 Reference Figure 5 , Attachment Figure 6 As shown, the telecentric lens module provided by the embodiment of the present invention also includes a first lens barrel and a telecentric lens base I11, the first lens barrel includes a first inner lens barrel I5 and a second inner lens barrel I6, the first lens L1, the second lens L2, the third lens L3 and the fourth lens L4 are installed in the first inner lens barrel I5, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are installed in the second inner lens barrel I6, the first inner lens barrel I5 and the second inner lens barrel I6 are both installed in the telecentric lens base I11; the flat beam splitter I1 is installed between the first inner lens barrel I5 and the second inner lens barrel I6, and the first reflector I2 is installed between the flat beam splitter I1 and the ninth lens L9, and both are installed in the telecentric lens base I11. Through the lens barrel installation, the overall installation accuracy is guaranteed and the installation process is simplified.

[0025] In one embodiment, the telecentric lens module adopts a method of working in cooperation with an area array telecentric lens module and a linear array telecentric lens module. A preliminary rapid detection is first performed with a linear array telecentric lens. When an abnormality is found in the detection result, it can be switched to an area array telecentric lens for more accurate detection, thereby improving detection efficiency and realizing high-speed real-time object projection contour detection.

[0026] In one embodiment, the telecentric lens module further includes a first protective glass I9 for preventing dust from entering the system to cause measurement errors and protecting the lens from being scratched.

[0027] In one embodiment, the telecentric lens module further includes a first reflector I2, and the entire optical path is folded by the reflector to reduce the volume of the telecentric lens module.

[0028] Reference Figure 7 As shown, the telecentric lighting module includes an illumination light source I15, a light rod I16, a second reflector I3, a thirteenth lens L13, a fourteenth lens L14, a third reflector I4, a fifteenth lens L15 and a sixteenth lens L16, which are arranged in sequence from the object side to the image side, and are all single lenses; the LED light emitted by the illumination light source I15 is homogenized by the light rod I16, is reflected by the second reflector I3, and is incident on the thirteenth lens L13, and is emitted by the sixteenth lens L16 to form a uniform telecentric light beam.

[0029] It can be seen from the above embodiments that the present application shapes the light emitted by the light source through the telecentric illumination module to realize the illumination of the object to be measured using a telecentric light beam, thereby improving the measurement accuracy and measurement depth of the contour of the object to be measured, and being able to obtain high-precision measurement effects in a larger range; by deflecting the light path through a reflector, the module volume is reduced, making it more suitable for industrial applications; and the illumination NA is controlled to improve the utilization rate of light energy.

[0030] In one embodiment, the thirteenth lens L13 in the telecentric illumination module is a positive focal length lens, with a convex incident surface and a convex exit surface; the fourteenth lens L14 is a positive focal length lens, with a convex incident surface and a concave exit surface; the fifteenth lens L15 is a positive focal length lens, with a concave incident surface and a convex exit surface; the sixteenth lens L16 is a positive focal length lens, with a convex incident surface and a convex exit surface. Through the reasonable combination of positive focal length lenses and negative focal length lenses, the aberration is greatly reduced and the measurement accuracy is improved.

[0031] In one embodiment, the glass material of the thirteenth lens L13 in the telecentric illumination module: 1.60 < n < 1.80, 30 < Vd < 50; the glass material of the fourteenth lens L14: 1.70 < n < 1.90, 20 < Vd < 40; the glass material of the fifteenth lens L15: 1.70 < n < 1.90, 20 < Vd < 40; the glass material of the sixteenth lens L16: 1.40 < n < 1.60, 60 < Vd < 80. Wherein, n is the refractive index and Vd is the Abbe number. Through the reasonable selection of the glass material, the chromatic aberration and aberration of the system are greatly reduced, and the measurement accuracy is improved.

[0032] In one embodiment, the distance between the thirteenth lens and the fourteenth lens in the telecentric illumination module is 0 mm, the distance between the fourteenth lens and the fifteenth lens is 90 - 100 mm, and the distance between the fifteenth lens and the sixteenth lens is 0 mm, making the overall structure of the lens compact. Among them, the light beam emitted by the light source is incident through the thirteenth lens L13 and exits through the sixteenth lens L16, collimated by the fourteenth lens L14, and converged by the fifteenth lens L15 and the sixteenth lens L16 to a working distance of 90 mm, forming a telecentric illumination beam with parallel principal rays. The illumination depth of field of the system is increased, and the range of high-precision measurement is improved. Table 2 gives the parameters of the telecentric illumination module.

[0033] Table 2 Parameters of the telecentric illumination module: surface Radius of curvature (unit / mm) Semi-diameter (unit / mm) The incident surface of the thirteenth lens L13 372 9.5 The thirteenth lens L13 exit surface -42 9.5 The incident surface of the fourteenth lens L14 32 9.5 The exit surface of the fourteenth lens L14 127.6 9.5 The incident surface of the fifteenth lens L15 -134.6 30 The fifteenth lens L15 exit surface -71.8 30 The incident surface of the sixteenth lens L16 179 30 The sixteenth lens L16 has an exit surface -179 30 Refer to the attached Figure 8 As shown, the telecentric illumination module provided in this embodiment further includes a second lens barrel and a telecentric illumination base I12. The second lens barrel includes a third inner lens barrel I7 and a fourth inner lens barrel I8. The thirteenth lens L13 and the fourteenth lens L14 are installed in the third inner lens barrel I7, and the fifteenth lens L15 and the sixteenth lens L16 are installed in the fourth inner lens barrel I8. The third inner lens barrel I7 and the fourth inner lens barrel I8 are both installed on the telecentric illumination base I12; between the illumination light source I15 and the third inner lens barrel I7, a light bar I16 and a second reflector I3 are installed, and between the third inner lens barrel I7 and the fourth inner lens barrel I8, a third reflector I4 is installed, all of which are installed on the telecentric illumination base I12.

[0034] In one embodiment, the telecentric illumination module further includes a second protective glass I10 for preventing dust from entering the system to cause measurement errors and protecting the lens from being scratched.

[0035] In one embodiment, the telecentric illumination module further includes a second reflector 13 and a third reflector 14. The overall optical path is folded by the two reflectors to reduce the volume of the telecentric illumination module.

[0036] In one embodiment, the illumination light source I15 is a monochromatic LED with a wavelength of 525 nm, and the light rod I16 is a rectangular glass rod with coatings on four sides and frosted ends. The light rod I16 is used to homogenize the illumination beam so that the brightness is uniform at the working distance of the illumination beam.

[0037] The telecentric illumination module corrects aberrations within a large depth of field, has a good point diagram morphology, and a long working distance of 90 mm. The image-side numerical aperture is 0.01, which matches the incident NA of the telecentric lens module, making full use of the system's NA and improving light energy utilization.

[0038] In one embodiment, the telecentric illumination module 30 and the telecentric lens module 10 can be adjusted respectively to match the NA of the illumination system and the receiving system, thereby improving the utilization rate of light energy and achieving high-precision measurement in dark light conditions.

[0039] The light beam emitted by the light source is shaped by the telecentric lighting module 30, so that the telecentric light beam can illuminate the object to be measured, thereby improving the measurement accuracy of the contour of the object to be measured. The telecentric lighting and telecentric lens are installed in the base, and the lens light path is folded by the reflector, making the overall structure of the lens compact. The telecentric lens module has a large depth of field range, realizing high-precision measurement within the range of ±5mm.

[0040] The light beam emitted by the light source of the present application becomes a uniform telecentric light beam after being uniformly shaped by the telecentric lighting module, which is conducive to realizing uniform and consistent high-precision measurement of each position of the object to be measured. The aberration is corrected within a larger depth of field, and a larger range of high-precision measurement is realized, which is suitable for the measurement of large-sized objects, and at the same time reduces the requirements for the placement of the object to be measured. The working distance of the telecentric lighting and the working distance of the telecentric lens are both 90mm, and the long working distance is conducive to the detection of large-sized objects to be measured. The present invention makes full use of the reflector to refract the light path, realizes a telecentric lighting and telecentric lens system with a compact structure and smaller size, and is more suitable for high-precision measurement applications in various industrial scenarios. The actual contour of the sample 20 to be measured can be calculated by measuring the shadow size of the sample through the host computer through the linear array image sensor I14 and the area array image sensor I13.

[0041] Those skilled in the art will readily appreciate other embodiments of the present application after considering the description and practicing the contents disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The description and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims.

[0042] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A high-precision and large depth-of-field projection diameter measuring device, characterized in that: It includes a telecentric lighting module and a telecentric lens module, wherein the telecentric lighting module and the telecentric lens module are arranged opposite to each other, and a light beam emitted by a light source is shaped into a telecentric lighting beam by the telecentric lighting module, and the light beam is blocked by a sample to be tested placed between the telecentric lighting module and the telecentric lens module, and then incident from the telecentric lens module, and is imaged onto an image sensor through the telecentric lens, so as to form a shadow image of the sample to be tested on the image sensor; The telecentric lens module includes a surface array telecentric lens module and a linear array telecentric lens module, wherein: The area array telecentric lens module comprises a first lens, a second lens, a third lens, a fourth lens, a flat beam splitter, a fifth lens, a sixth lens, a seventh lens, an eighth lens and an area array image sensor which are sequentially arranged from the object side to the image side, wherein the first lens and the second lens form a first closely connected double-cemented lens, the third lens and the fourth lens form a closely connected second double-cemented lens, the fifth lens and the sixth lens form a closely connected third double-cemented lens, and the seventh lens and the eighth lens form a closely connected fourth double-cemented lens; The linear array telecentric lens module comprises a first reflector, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a linear array image sensor which are arranged in sequence from the object side to the image side, the ninth lens and the tenth lens form a fifth close-contact double-cemented lens, and the eleventh lens and the twelfth lens form a sixth close-contact double-cemented lens; The telecentric illumination beam is blocked by the sample to be tested and then incident on the first lens. After being transmitted and reflected by the flat beam splitter, it is emitted from the eighth lens and the twelfth lens respectively, and the shadow image of the sample to be tested is obtained on the area array image sensor and the line array image sensor respectively.

2. The high-precision large depth of field projection diameter measuring device according to claim 1, characterized in that: The first lens is a positive power lens, with a convex incident surface and a convex exit surface; the second lens is a positive power lens, with a concave incident surface and a convex exit surface; the third lens is a positive power lens, with a convex incident surface and a convex exit surface; the fourth lens is a negative power lens, with a concave incident surface and a concave exit surface; the fifth lens is a negative power lens, with a concave incident surface and a concave exit surface; the sixth lens is a positive power lens, with a convex incident surface and a convex exit surface; The seventh lens is a positive power lens, with a convex incident surface and a convex exit surface; the eighth lens is a negative power lens, with a concave incident surface and a flat exit surface; the ninth lens is a negative power lens, with a concave incident surface and a concave exit surface; the tenth lens is a positive power lens, with a convex incident surface and a convex exit surface; the eleventh lens is a positive power lens, with a convex incident surface and a convex exit surface; the twelfth lens is a negative power lens, with a concave incident surface and a convex exit surface.

3. The high-precision large depth of field projection diameter measuring device according to claim 1, characterized in that: The glass material of the first lens: 1.60 < n < 1.80, 30 < Vd < 50; the glass material of the second lens: 1.60 < n < 1.80, 20 < Vd < 40; the glass material of the third lens: 1.60 < n < 1.80, 30 < Vd < 50; the glass material of the fourth lens: 1.70 < n < 1.90, 15 < Vd < 35; the glass material of the fifth lens: 1.65 < n < 1.85, 20 < Vd < 40; the glass material of the sixth lens: 1.60 < n < 1.80, 30 < Vd < 50; the glass material of the seventh lens: 1.60 < n < 1.80, 40 < Vd < 60; the glass material of the eighth lens: 1.60 < n < 1.80, 25 < Vd < 45; the glass material of the ninth lens: 1.70 < n < 1.90, 15 < Vd < 35; the glass material of the tenth lens: 1.55 < n < 1.75, 40 < Vd < 60; the glass material of the eleventh lens: 1.60 < n < 1.80, 25 < Vd < 45; the glass material of the twelfth lens: 1.50 < n < 1.70, 40 < Vd < 60; where n is the refractive index and Vd is the Abbe number.

4. The high-precision large depth of field projection diameter measuring device according to claim 1, characterized in that: The distance between the first lens and the second lens is 0 mm, the distance between the second lens and the third lens is 0 mm, the distance between the third lens and the fourth lens is 0 mm, the distance between the fourth lens and the fifth lens is 30 - 40 mm, the distance between the fifth lens and the sixth lens is 0 mm, the distance between the sixth lens and the seventh lens is 0 mm, the distance between the seventh lens and the eighth lens is 0 mm, the distance between the eighth lens and the area array image sensor is 10 - 20 mm; the distance between the fourth lens and the ninth lens is 40 - 50 mm, the distance between the ninth lens and the tenth lens is 0 mm, the distance between the tenth lens and the eleventh lens is 0 mm, the distance between the eleventh lens and the twelfth lens is 0 mm, the distance between the twelfth lens and the linear array image sensor is 20 - 30 mm.

5. The high-precision large depth of field projection diameter measuring device according to claim 1, characterized in that: The telecentric lens module further includes a first lens barrel and a telecentric lens base. The first lens barrel includes a first inner lens barrel and a second inner lens barrel. The first lens, the second lens, the third lens, and the fourth lens are installed in the first inner lens barrel. The fifth lens, the sixth lens, the seventh lens, and the eighth lens are installed in the second inner lens barrel. Both the first inner lens barrel and the second inner lens barrel are installed on the telecentric lens base; the plate beam splitter is installed between the first inner lens barrel and the second inner lens barrel, and the first reflector is installed between the plate beam splitter and the ninth lens, and both are installed on the telecentric lens base.

6. The high-precision large depth of field projection diameter measuring device according to claim 1, characterized in that: The telecentric illumination module includes, in sequence from the object side to the image side, an illumination light source, a light bar, a second reflector, a thirteenth lens, a fourteenth lens, a third reflector, a fifteenth lens, and a sixteenth lens, all of which are single lenses; the LED light emitted by the illumination light source is subjected to light field homogenization through the light bar, and after being reflected by the second reflector, it is incident on the thirteenth lens and exits from the sixteenth lens to form a uniform field telecentric light beam.

7. The high-precision large depth of field projection diameter measuring device according to claim 6, characterized in that: The thirteenth lens is a positive focal length lens, with a convex incident surface and a convex exit surface; the fourteenth lens is a positive focal length lens, with a convex incident surface and a concave exit surface; the fifteenth lens is a positive focal length lens, with a concave incident surface and a convex exit surface; the sixteenth lens is a positive focal length lens, with a convex incident surface and a convex exit surface.

8. The high-precision large depth-of-field projection diameter measuring device according to claim 6, characterized in that: The glass material of the thirteenth lens: 1.60 < n < 1.80, 30 < Vd < 50; the glass material of the fourteenth lens: 1.70 < n < 1.90, 20 < Vd < 40; the glass material of the fifteenth lens: 1.70 < n < 1.90, 20 < Vd < 40; the glass material of the sixteenth lens: 1.40 < n < 1.60, 60 < Vd < 80.

9. The high-precision large depth of field projection diameter measuring device according to claim 6, characterized in that: The distance between the thirteenth lens and the fourteenth lens in the telecentric illumination module is 0 mm, the distance between the fourteenth lens and the fifteenth lens is 90 - 100 mm, and the distance between the fifteenth lens and the sixteenth lens is 0 mm.

10. The high-precision large depth-of-field projection diameter measuring device according to claim 6, characterized in that: The telecentric illumination module further includes a second lens barrel and a telecentric illumination base. The second lens barrel includes a third inner lens barrel and a fourth inner lens barrel. The thirteenth lens and the fourteenth lens are installed in the third inner lens barrel, the fifteenth lens and the sixteenth lens are installed in the fourth inner lens barrel, and both the third inner lens barrel and the fourth inner lens barrel are installed on the telecentric illumination base; the light bar and the second reflector are installed between the illumination light source and the third inner lens barrel, and the third reflector is installed between the third inner lens barrel and the fourth inner lens barrel, and all are installed on the telecentric illumination base.

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