A Linear Spectral Confocal Dispersion Objective with Large Field of View and Measurement System

Abstract

The present invention discloses a line spectrum confocal dispersion objective lens and a measurement system with a large field of view. The dispersion objective lens includes a first lens to a thirteenth lens arranged in sequence from the object side to the image side. The light beam emitted by the light source is incident on the first lens and emitted by the thirteenth lens to form a dispersion light. After the dispersion light is irradiated to the surface of the object to be measured, according to the different positions of the object to be measured, the reflected light of different wavelengths is reflected back. The reflected light is incident on the thirteenth lens and emitted by the first lens. The line spectrum confocal measurement system includes a light source, two flat-field relay lenses, a semi-transparent and semi-reflective mirror, a detector, a slit, a collimating lens, a focusing lens, a grating and a line spectrum confocal dispersion objective lens. The present invention has an image side field of view of 13mm, a measurement depth of 2mm, and a structure that is easy to assemble, and is suitable for various industrial measurement scenarios.

Description

Technical Field

[0001] The present application relates to the field of optical measurement technology, and in particular to a large-field-of-view linear spectrum confocal dispersion objective lens and a measurement system. Background Art

[0002] Spectral confocal technology is an emerging high-precision optical measurement technology. It uses the characteristics of optical dispersion to focus light of different wavelengths at different axial positions, achieving a one-to-one correspondence between wavelength and position. By calculating the measured wavelength, the position information can be obtained, thereby achieving accurate measurement of the position information of the object being measured. This technology can measure the displacement, thickness, and surface profile of an object under non-destructive and non-contact conditions. It has fast response speed, high measurement accuracy, and strong ability to adapt to complex surfaces. It shows great potential, especially in the fields of industrial measurement, precision manufacturing, electronics, and semiconductors.

[0003] Spectral confocal technology mainly includes two technologies: point scanning and line scanning. Point scanning technology focuses light on a single point and measures point by point. It has extremely high measurement accuracy and is suitable for precision measurement of small ranges and microstructures. However, since it needs to be coordinated with a two-dimensional translation stage to scan point by point, the measurement speed is slow. In contrast, line scanning technology expands the light source into a line and can simultaneously measure multiple points along the line, greatly improving the measurement speed. It is very suitable for large-scale, fast measurement applications while maintaining high accuracy, and is a more efficient solution in industrial measurement.

[0004] The dispersive objective is the core of the line spectrum confocal measurement system, and its performance directly affects the overall measurement capability of the line spectrum confocal measurement system. The axial dispersion range of the dispersive objective determines the measurement depth of the line spectrum confocal measurement system, the focal length determines the working distance of the system, the image side numerical aperture determines the maximum tilt angle that the system can measure, and the image side field of view, i.e., the line length, determines the lateral measurement range that can be covered during each scan.

[0005] In industrial measurement, different objects and measurement scenarios require different measurement depths and working distances. Among the existing technologies of related spectral confocal dispersive objective lenses, most are based on point scanning technology, which requires point-by-point measurement and has a slow measurement speed. In a few patents of dispersive objective lenses that are based on line scanning, the measurement depth of the dispersive objective lens is small, which cannot meet some industrial measurement scenarios, and the field of view of the system is small, resulting in a small lateral measurement range that can be covered during each scan, reducing the measurement efficiency of the system. Summary of the invention

[0006] In view of this, the embodiment of the present application provides a line spectrum confocal dispersion objective lens with a large field of view and a measurement system, which can expand the image field of view while increasing the axial measurement depth and working distance, thereby increasing the line length of the line spectrum confocal dispersion objective lens, thereby increasing the measurement speed of the line spectrum confocal dispersion system, and correcting aberrations, thereby improving measurement accuracy. The dispersion objective lens has a simple and compact structure, low assembly difficulty, and strong practicality.

[0007] According to a first aspect of an embodiment of the present application, there is provided a line spectrum confocal dispersion objective lens with a large field of view, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens arranged in sequence from the object side to the image side, wherein the first lens and the second lens constitute a first cemented lens, the third lens and the fourth lens constitute a second cemented lens, the fifth lens and the sixth lens constitute a third cemented lens, the seventh lens and the eighth lens constitute a fourth cemented lens, the tenth lens and the eleventh lens constitute a fifth cemented lens, the twelfth lens and the thirteenth lens constitute a sixth cemented lens, and the ninth lens is a single lens;

[0008] The light beam emitted by the light source is incident on the first lens and emitted by the thirteenth lens to form dispersed light. After the dispersed light is irradiated on the surface of the object to be measured, it reflects back reflected light of different wavelengths according to the different positions of the object to be measured. The reflected light is incident on the thirteenth lens and emitted by the first lens.

[0009] Optionally, the first lens is a positive power lens, the incident surface is convex, and the exit surface is convex; the second lens is a negative power lens, the incident surface is concave, and the exit surface is concave; the third lens is a positive power lens, the incident surface is concave, and the exit surface is convex; the fourth lens is a positive power lens, the incident surface is concave, and the exit surface is convex; the fifth lens is a negative power lens, the incident surface is concave, and the exit surface is concave; the sixth lens is a positive power lens, the incident surface is convex, and the exit surface is convex; the seventh lens is a positive power lens The eighth lens is a positive power lens, with a concave incident surface and a convex exit surface; the ninth lens is a positive power lens, with a convex incident surface and a convex exit surface; the tenth lens is a negative power lens, with a concave incident surface and a convex exit surface; the eleventh lens is a positive power lens, with a concave incident surface and a convex exit surface; the twelfth lens is a negative power lens, with a convex incident surface and a concave exit surface; the thirteenth lens is a positive power lens, with a convex incident surface and a flat exit surface.

[0010] Optionally, the glass material of the first lens: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the second lens: 1.5 < n < 1.7, 50 < Vd < 70; the glass material of the third lens: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the fourth lens: 1.75 < n < 1.95, 15 < Vd < 30; the glass material of the fifth lens: 1.75 < n < 1.95, 15 < Vd < 35; the glass material of the sixth lens: 1.55 < n < 1.75, 45 < Vd < 65; the glass material of the seventh lens: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the eighth lens: 1.45 < n < 1.65, 45 < Vd < 65; the glass material of the ninth lens: 1.75 < n < 1.95, 15 < Vd < 35; the glass material of the tenth lens: 1.5 < n < 1.7, 45 < Vd < 65; the glass material of the eleventh lens: 1.45 < n < 1.65, 40 < Vd < 60; the glass material of the twelfth lens: 1.6 < n < 1.8, 40 < Vd < 60; the glass material of the thirteenth lens: 1.5 < n < 1.7, 45 < Vd < 65; where n is the refractive index and Vd is the Abbe number.

[0011] Optionally, the first lens, the third lens, and the seventh lens are made of the same glass material; the fourth lens and the ninth lens are made of the same glass material.

[0012] Optionally, the distance between the first cemented lens and the second cemented lens is 9.5 mm to 10.5 mm, the distance between the second cemented lens and the third cemented lens is 0 mm, the distance between the third cemented lens and the fourth cemented lens is 23 mm to 28 mm, the distance between the fourth cemented lens and the ninth lens is 95 mm to 100 mm, the distance between the ninth lens and the fifth cemented lens is 20 mm to 25 mm, and the distance between the fifth cemented lens and the sixth cemented lens is 0 mm.

[0013] According to the second aspect of the embodiments of the present application, a line spectrum confocal measurement system is provided, including a light source, a first flat-field relay lens, a second flat-field relay lens, a semi-transmissive semi-reflective mirror, a detector, a slit, a collimating lens, a focusing lens, a grating, and the large-field-of-view line spectrum confocal dispersion objective lens described in the first aspect. The light source is arranged on the object side, and the object to be measured is arranged on the image side. The light source is used to generate white light and make the white light form colored light after passing through the dispersion objective lens and irradiate the object to be measured.

[0014] The light emitted by the light source passes through the first flat-field relay lens and the semi-transparent and semi-reflective mirror to generate a conjugate light source in the optical path to expand the distance between the light source and the dispersive objective lens; the white light transmitted through the semi-transparent and semi-reflective mirror into the dispersive objective lens generates axial dispersion; the axially dispersed light is irradiated on the object to be measured, reflected by the surface of the object to be measured, reversely passes through the dispersive objective lens, is reflected by the semi-transparent and semi-reflective mirror, and forms an image conjugate with the light source after passing through the second flat-field relay lens, and the slit is used to eliminate the interference of stray light; thereafter, the collimating lens disperses light of different wavelengths, which is then split by the grating and finally focused on the detector by the focusing lens.

[0015] Optionally, the light source is a one-dimensional optical fiber array consisting of multiple point light sources, or a line light source generated by a slit.

[0016] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0017] It can be seen from the above embodiments that the light beam emitted by the light source is incident on the first lens and emitted by the thirteenth lens to form dispersed light, and the dispersed light is irradiated to the object to be measured to form reflected light, and the reflected light is incident on the thirteenth lens and emitted by the first lens. Among them, after the light beam emitted by the light source is converged by the first cemented lens and diverged by the second cemented lens, the axial chromatic aberration is introduced by the third cemented lens, and then further converged by the fourth cemented lens to form an approximately parallel light beam, and a larger image field of view is generated by controlling the distance interval between the fourth cemented lens and the ninth lens, and then the spherical aberration of the system is further corrected by the fifth cemented lens and the sixth cemented lens, and the telecentricity of the image side is ensured. A line spectrum confocal measurement system can be obtained by combining a light source, a first flat field relay lens, a second flat field relay lens, a semi-transparent and semi-reflective mirror, a detector, a slit, a collimating lens, a focusing lens, a grating and a dispersion objective lens. The system achieves a 13mm image field of view on the premise of achieving a 2mm depth of field, and the structure is relatively simple, the assembly difficulty is relatively low, and it is suitable for various industrial scenes.

[0018] 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

[0019] 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.

[0020] Figure 1 is an optical structure diagram of a line spectrum confocal dispersion objective lens provided by an embodiment of the present invention;

[0021] Figure 2 is a point diagram of a line spectrum confocal dispersion objective lens at a wavelength of 450 nm provided by an embodiment of the present invention;

[0022] Figure 3 is a point diagram of a line spectrum confocal dispersion objective lens provided by an embodiment of the present invention at a wavelength of 585 nm;

[0023] Figure 4 is a point diagram of a line spectrum confocal dispersion objective lens provided by an embodiment of the present invention at a wavelength of 656 nm;

[0024] Figure 5 is a light trace diagram of a line spectrum confocal dispersion objective lens at a wavelength of 450 nm provided by an embodiment of the present invention;

[0025] Figure 6 is a light trace diagram of a line spectrum confocal dispersion objective lens at a wavelength of 585 nm provided by an embodiment of the present invention;

[0026] Figure 7 is a light trace diagram of a line spectrum confocal dispersion objective lens at a wavelength of 656 nm provided by an embodiment of the present invention;

[0027] Figure 8 is a graph showing the relationship between wavelength and position of a line spectrum confocal dispersion objective lens provided by an embodiment of the present invention;

[0028] Fig. 9 It is a structural schematic diagram of a line spectrum confocal measurement system provided by an embodiment of the present invention.

[0029] In the figure:

[0030] 11, first lens; 12, second lens; 13, third lens; 14, fourth lens; 15, fifth lens; 16, sixth lens; 17, seventh lens; 18, eighth lens; 19, ninth lens; 110, tenth lens; 111, eleventh lens; 112, twelfth lens; 113, thirteenth lens;

[0031] L1, first cemented lens; L2, second cemented lens; L3, third cemented lens; L4, fourth cemented lens; L5, fifth cemented lens; L6, sixth cemented lens;

[0032] t1, light source; t2, first flat-field relay lens; t3, semi-transparent and semi-reflective mirror; t4, line spectrum confocal dispersion objective lens; t5, object to be measured; t6, second flat-field relay lens; t7, slit; t8, collimating lens; t9, grating; t10, focusing lens; t11, detector. DETAILED DESCRIPTION

[0033] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0034] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application 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 in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0035] 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".

[0036] Reference Figure 1 As shown, the embodiment of the present invention provides a linear spectrum confocal dispersion objective lens with a large field of view, comprising a first lens l1, a second lens l2, a third lens l3, a fourth lens l4, a fifth lens l5, a sixth lens l6, a seventh lens l7, an eighth lens l8, a ninth lens l9, a tenth lens l10, an eleventh lens l11, a twelfth lens l12, and a thirteenth lens l13, 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 cemented lens L1, the third lens l3 and the fourth lens l4 form a second cemented lens L2, and the fifth lens l5 and the sixth lens l6 form a third The seventh lens l7 and the eighth lens l8 form a fourth cemented lens L4, the tenth lens l10 and the eleventh lens l11 form a fifth cemented lens L5, the twelfth lens l12 and the thirteenth lens l13 form a sixth cemented lens L6, and the ninth lens l9 is a single lens; the light beam emitted by the light source is incident on the first lens l1 and emitted by the thirteenth lens l13 to form dispersed light, and after the dispersed light is irradiated to the surface of the measured object, it reflects back reflected light of different wavelengths according to different positions of the measured object, and the reflected light is incident on the thirteenth lens l13 and emitted by the first lens l1.

[0037] In one embodiment, the light beam emitted by the light source is incident on the first lens l1 and exits from the thirteenth lens l13, where: the first lens l1 is a positive focal length lens, the incident surface is convex, and the exit surface is convex; the second lens l2 is a negative focal length lens, the incident surface is concave, and the exit surface is concave; the third lens l3 is a positive focal length lens, the incident surface is concave, and the exit surface is convex; the fourth lens l4 is a positive focal length lens, the incident surface is concave, and the exit surface is convex; 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 positive focal length lens, the incident surface is concave, and the exit surface is convex; the ninth lens l9 is a positive focal length lens, the incident surface is convex, and the exit surface is concave; the tenth lens l10 is a negative focal length lens, the incident surface is concave, and the exit surface is convex; the eleventh lens l11 is a positive focal length lens, the incident surface is concave, and the exit surface is convex; the twelfth lens l12 is a negative focal length lens, the incident surface is convex, and the exit surface is concave; the thirteenth lens l13 is a positive focal length lens, the incident surface is convex, and the exit surface is flat. Through the reasonable combination of positive focal length lenses and negative focal length lenses, the aberration of the system is greatly reduced, and the measurement accuracy is improved.

[0038] In one embodiment, the glass material of the first lens l1: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the second lens l2: 1.5 < n < 1.7, 50 < Vd < 70; the glass material of the third lens l3: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the fourth lens l4: 1.75 < n < 1.95, 15 < Vd < 30; the glass material of the fifth lens l5: 1.75 < n < 1.95, 15 < Vd < 35; the glass material of the sixth lens l6: 1.55 < n < 1.75, 45 < Vd < 65; the glass material of the seventh lens l7: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the eighth lens l8: 1.45 < n < 1.65, 45 < Vd < 65; the glass material of the ninth lens l9: 1.75 < n < 1.95, 15 < Vd < 35; the glass material of the tenth lens l10: 1.5 < n < 1.7, 45 < Vd < 65; the glass material of the eleventh lens l11: 1.45 < n < 1.65, 40 < Vd < 60; the glass material of the twelfth lens l12: 1.6 < n < 1.8, 40 < Vd < 60; the glass material of the thirteenth lens l13: 1.5 < n < 1.7, 45 < Vd < 65; where n is the refractive index and Vd is the Abbe number. By reasonably selecting the lens glass materials, the spherical aberration, coma aberration and other aberrations of the system are greatly reduced to improve the measurement accuracy of the system.

[0039] In one embodiment, the first lens 11, the third lens 13 and the seventh lens 17 are made of the same glass material; the fourth lens 14 and the ninth lens 19 are made of the same glass material. Such a design can simplify the manufacturing process, reduce costs, and reduce the chromatic aberration caused by material differences and the instability of optical performance caused by temperature changes, thereby improving the overall imaging quality and stability of the system.

[0040] In one embodiment, the distance between the first cemented lens L1 and the second cemented lens L2 is 9.5mm-10.5mm, the distance between the second cemented lens L2 and the third cemented lens L3 is 0mm, the distance between the third cemented lens L3 and the fourth cemented lens L4 is 23mm-28mm, the distance between the fourth cemented lens L4 and the ninth lens L9 is 95mm-100mm, the distance between the ninth lens L9 and the fifth cemented lens L5 is 20mm-25mm, and the distance between the fifth cemented lens L5 and the sixth cemented lens L6 is 0mm. Such a design makes the overall structure of the lens compact, achieves a balance between imaging quality and compact structure, and makes the system more flexible in application without sacrificing performance.

[0041] In one embodiment, Table 1 gives the parameters of the dispersion objective lens group. Figure 2 The point diagram of the dispersion objective lens at different viewing fields at a wavelength of 450nm is shown in the figure below. Figure 3 The spot diagram of the dispersion objective lens at different viewing fields at a wavelength of 585 nm is shown in the figure below. Figure 4 The spot diagram of the dispersion objective lens at different fields of view at a wavelength of 656nm shows that the spot size at each field of view is close to the Airy disk size, and the system is close to the diffraction limit. Figure 8 It shows that the dispersion objective lens has a measurement depth of 2mm at a wavelength of 450~656nm, which can ensure high-precision measurement at a depth of field of 2mm. Figure 5 The light trace diagram of the dispersion objective lens at a wavelength of 450nm is shown in the figure below. Figure 6 The light trace diagram of the dispersion objective lens at a wavelength of 585nm is shown in the figure below. Figure 7 This is the light trace diagram of the dispersive objective lens at a wavelength of 656nm. The light trace diagram shows that the image field of view of the system reaches 13mm, which indicates that the dispersive objective lens can not only achieve high-precision measurement in the visible light range, but also ensure high optical performance within a large field of view.

[0042] Table 1 Parameters of lens group

[0043] surface Radius of curvature (unit / mm) Semi-diameter (unit / mm) The first lens l1 incident surface 23.2 11.379 The first lens l1 exit surface -32.5 10.783 The second lens l2 incident surface -32.5 10.783 The second lens l2 exit surface 16 8.584 The third lens l3 incident surface -12.1 8.333 The third lens l3 exit surface -16 13 The fourth lens l4 incident surface -16 13 The fourth lens l4 exit surface -24.2 13 The incident surface of the fifth lens l5 -64.2 13.603 Fifth lens l5 exit surface 50.9 15.042 The incident surface of the sixth lens l6 50.9 15.042 The sixth lens l6 exit surface -36.9 15.621 The incident surface of the seventh lens l7 209.7 19.555 The seventh lens l7 exit surface -55.4 19.663 The incident surface of the eighth lens l8 -55.4 19.663 The eighth lens l8 exit surface -89.9 19.551 The ninth lens l9 incident surface 46.5 10.311 The ninth lens l9 exit surface 266.7 10.036 The incident surface of the tenth lens l10 -23.2 8.58 The tenth lens l10 exit surface -12.6 10.5 The incident surface of the eleventh lens l11 -12.6 10.5 The eleventh lens l11 exit surface -31 10.5 The incident surface of the twelfth lens l12 40.2 10.5 The twelfth lens l12 exit surface 40.2 10.5 The incident surface of the thirteenth lens l13 12 10.5 The thirteenth lens l13 exit surface unlimited 8.233

[0044] Reference Fig. 9The embodiment of the present invention further provides a line spectrum confocal measurement system, comprising a light source t1, a first flat field relay lens t2, a second flat field relay lens t6, a semi-transparent and semi-reflective mirror t3, a detector t11, a slit t7, a collimating lens t8, a focusing lens t10, a grating t9 and the above-mentioned large field of view line spectrum confocal dispersion objective lens t4. The light source t1 is arranged on the object side, and the object to be measured t5 is arranged on the image side. The light source t1 is used to generate white light and make the white light pass through the dispersion objective lens t4 to form dispersed light to irradiate the object to be measured.

[0045] The light emitted by the light source passes through the first flat-field relay lens t2 and the semi-transparent and semi-reflective mirror t3 to generate a conjugate light source in the optical path to expand the distance between the light source t1 and the dispersive objective lens t4; the white light transmitted through the semi-transparent and semi-reflective mirror t3 and entering the dispersive objective lens t4 generates axial dispersion; the axially dispersed light is irradiated on the object to be measured t5, reflected by the surface of the object to be measured t5, reversely passes through the dispersive objective lens t4, and is reflected by the semi-transparent and semi-reflective mirror t3, and after passing through the second flat-field relay lens t6, an image conjugate with the light source is formed, and the slit t7 is used to eliminate the interference of stray light; thereafter, the collimating lens t8 disperses the light of different wavelengths, which is then split by the grating t9 and finally focused on the detector t11 through the focusing lens t10.

[0046] It can be seen from the above embodiments that the present application provides a line spectrum confocal dispersion objective lens with a large field of view. Under the premise of a large field of view, the aberration is effectively corrected, and a measurement depth of 2mm is completed through dispersion, and an image field of view of 13mm is achieved. The structure is relatively simple, the assembly difficulty is relatively low, and it is suitable for various industrial measurement scenarios. The present application also provides a line spectrum confocal measurement system, including a light source t1, a first flat field relay lens t2, a second flat field relay lens t6, a semi-transparent and semi-reflective mirror t3, a detector t11, a slit t7, a collimating lens t8, a focusing lens t10, a grating t9 and a line spectrum confocal dispersion objective lens t4, which can effectively measure the displacement and thickness within a depth of 2mm, and has a large field of view of 13mm. The contour of the object to be measured can be efficiently scanned by matching a two-dimensional displacement stage to obtain high-precision three-dimensional information.

[0047] 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 variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application. The description and examples are intended to be exemplary only.

[0048] It will be appreciated that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A line spectrum confocal dispersion objective lens with a large field of view, characterized in that: The invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a thirteenth lens which are arranged in sequence from the object side to the image side, wherein the first lens and the second lens form a first cemented lens, the third lens and the fourth lens form a second cemented lens, the fifth lens and the sixth lens form a third cemented lens, the seventh lens and the eighth lens form a fourth cemented lens, the tenth lens and the eleventh lens form a fifth cemented lens, the twelfth lens and the thirteenth lens form a sixth cemented lens, and the ninth lens is a single lens; The optical components with optical power in the line spectrum confocal dispersion objective are only the thirteen lenses mentioned above; The light beam emitted by the light source is incident on the first lens and emitted by the thirteenth lens to form dispersed light. After the dispersed light is irradiated on the surface of the object to be measured, it reflects back reflected light of different wavelengths according to different positions of the object to be measured. The reflected light is incident on the thirteenth lens and emitted by the first lens. The distance between the fourth cemented lens and the ninth lens is 95 mm to 100 mm; The first lens is a positive power lens, with a convex incident surface and a convex exit surface; the second lens is a negative power lens, with a concave incident surface and a concave exit surface; the third lens is a positive power lens, with a concave incident surface and a convex exit surface; the fourth lens is a positive power lens, with a concave incident surface and a convex 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, The incident surface is convex, and the exit surface is convex; the eighth lens is a positive power lens, the incident surface is concave, and the exit surface is convex; the ninth lens is a positive power lens, the incident surface is convex, and the exit surface is concave; the tenth lens is a negative power lens, the incident surface is concave, and the exit surface is convex; the eleventh lens is a positive power lens, the incident surface is concave, and the exit surface is convex; the twelfth lens is a negative power lens, the incident surface is convex, and the exit surface is concave; the thirteenth lens is a positive power lens, the incident surface is convex, and the exit surface is a plane; The glass material of the first lens: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the second lens: 1.5 < n < 1.7, 50 < Vd < 70; the glass material of the third lens: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the fourth lens: 1.75 < n < 1.95, 15 < Vd < 30; the glass material of the fifth lens: 1.75 < n < 1.95, 15 < Vd < 35; the glass material of the sixth lens: 1.55 < n < 1.75, 45 < Vd < 65; the glass material of the seventh lens: 1.7 < n < 1.9, 40 < Vd < 60; the glass material of the eighth lens: 1.45 < n < 1.65, 45 < Vd < 65; the glass material of the ninth lens: 1.75 < n < 1.95, 15 < Vd < 35; the glass material of the tenth lens: 1.5 < n < 1.7, 45 < Vd < 65; the glass material of the eleventh lens: 1.45 < n < 1.65, 40 < Vd < 60; the glass material of the twelfth lens: 1.6 < n < 1.8, 40 < Vd < 60; the glass material of the thirteenth lens: 1.5 < n < 1.7, 45 < Vd < 65; where n is the refractive index and Vd is the Abbe number.

2. A linear spectrum confocal dispersion objective lens with a large field of view according to claim 1, characterized in that: The first lens, the third lens and the seventh lens adopt the same kind of glass material; the fourth lens and the ninth lens adopt the same kind of glass material.

3. The large-field-of-view linear spectrum confocal dispersion objective lens according to claim 1, characterized in that: The distance between the first cemented lens and the second cemented lens is 9.5 mm to 10.5 mm, the distance between the second cemented lens and the third cemented lens is 0 mm, the distance between the third cemented lens and the fourth cemented lens is 23 mm to 28 mm, the distance between the ninth lens and the fifth cemented lens is 20 mm to 25 mm, and the distance between the fifth cemented lens and the sixth cemented lens is 0 mm.

4. A line spectrum confocal measurement system, characterized in that: It includes a light source, a first flat-field relay lens, a second flat-field relay lens, a semi-transmissive and semi-reflective mirror, a detector, a slit, a collimating lens, a focusing lens, a grating and the large-field-of-view line-spectrum confocal dispersion objective lens according to any one of claims 1-3; the light source is arranged on the object side, and the object to be measured is arranged on the image side, and the light source is used to generate white light and make the white light form chromatic dispersion light after passing through the dispersion objective lens and irradiate the object to be measured. The light emitted by the light source passes through the first flat-field relay lens and the semi-transmissive and semi-reflective mirror to generate a conjugate light source in the optical path, so as to increase the distance between the light source and the dispersion objective lens. The white light transmitted through the semi-transmissive and semi-reflective mirror into the dispersion objective lens generates axial chromatic dispersion; the axially chromatic dispersion light irradiates on the object to be measured, is reflected by the surface of the object to be measured, passes through the dispersion objective lens reversely, is reflected by the semi-transmissive and semi-reflective mirror, and forms an image conjugate to the light source after passing through the second flat-field relay lens. The slit is used to eliminate the interference of stray light. After that, the collimating lens disperses the light of different wavelengths, and then is spectrally analyzed by the grating, and finally is focused on the detector by the focusing lens.

5. The line spectrum confocal measurement system according to claim 4, characterized in that: The light source is a one-dimensional optical fiber array composed of multiple point light sources, or a line light source generated through a slit.

Images