Dual telecentric lens, optical system and semiconductor device

Abstract

The application discloses a kind of double telecentric lens, optical system and semiconductor equipment, belong to optical equipment technical field.The double telecentric lens provided by the application includes first lens group, second lens group, third lens group and fourth lens group arranged in sequence along the direction of optical axis.The first lens group is sequentially composed of first prism, second lens, third lens, fourth lens, fifth lens and sixth lens.The second lens group is sequentially composed of seventh lens, eighth lens, ninth prism and tenth lens.The third lens group is sequentially composed of eleventh lens, twelfth prism and thirteenth lens.The fourth lens group is sequentially composed of fourteenth lens and fifteenth parallel flat plate.In the scheme, the double telecentric lens adopts the optical architecture of front and rear lens group cooperation, and the front lens group serves as a short-focus converging unit, which preliminarily converges light rays and corrects basic chromatic aberration;The rear lens group serves as a long-focus imaging unit, which balances aberration and realizes high magnification and flat image plane.

Description

Technical Field

[0001] This application relates to the field of optical equipment technology, and in particular to a dual telecentric lens, an optical system, and a semiconductor device. Background Technology

[0002] As integrated circuit technology nodes continue to shrink and process complexity increases, semiconductor manufacturing places near-limit demands on the resolution, magnification, and field-of-view uniformity of optical inspection lenses. However, existing technologies have significant limitations: mainstream products either fail to meet the high-precision magnification requirements for sub-micron features, or sacrifice edge resolution and image plane flatness while achieving higher magnification. More importantly, these lenses generally lack systematic stray light suppression design, leading to decreased image contrast, loss of edge sharpness, and difficulty in obtaining stable and reliable inspection images in highly reflective or high-contrast scenarios.

[0003] Therefore, there is an urgent need for an optical lens that can achieve a system-level balance between high magnification, high resolution, excellent image uniformity and superior stray light suppression capabilities, in order to support quality control and yield management in advanced semiconductor manufacturing. Summary of the Invention

[0004] This application provides a dual telecentric lens, an optical system, and a semiconductor device. The dual telecentric lens employs a cooperative optical architecture with front and rear lens groups. The front lens group acts as a short-focal-length converging unit, initially converging object-side rays and correcting fundamental chromatic aberration. The rear lens group acts as a long-focal-length imaging unit, balancing aberrations and achieving high magnification and a flat image plane. This results in a high-magnification, high-resolution, and compact dual telecentric lens, capable of meeting the application requirements of high-precision imaging and measurement scenarios.

[0005] To achieve the above objectives, according to a first aspect of this application, a dual telecentric lens is provided, comprising: a front lens group, an aperture stop, and a rear lens group arranged sequentially along the optical axis.

[0006] The front lens group consists of a first lens group with positive optical power;

[0007] The rear lens group consists of a second lens group with positive optical power, a third lens group with negative optical power, and a fourth lens group with positive optical power.

[0008] The focal length f of the front lens group G1 The focal length f of the rear lens group G2 The relation 0.014 < f is satisfied. G1 / f G2 <0.034;

[0009] The total optical length TTL of a double telecentric lens and the focal length f of a double telecentric lens satisfy the following relationship: 0.42 < TTL / f < 1.65.

[0010] According to a second aspect of this application, an optical system is provided, the optical system comprising:

[0011] An illumination module is used to emit an illumination beam to illuminate the object under test;

[0012] An optical imaging module having a double telecentric lens as described in any of the above technical solutions, for receiving a light beam from the object under test;

[0013] The photosensitive module, located at the image plane of the optical imaging module, is used to receive the imaging beam and convert the light signal into an electrical signal for imaging.

[0014] The optical imaging module also has an extinction unit, which is used to absorb or block non-imaging light.

[0015] According to a third aspect of this application, a semiconductor device is provided, the semiconductor device comprising:

[0016] The double telecentric lens described in any of the above technical solutions, or the optical system described in any of the above technical solutions.

[0017] In the dual telecentric lens of this application embodiment, an optical architecture of coordinated front and rear lens groups is adopted. The front lens group serves as a short-focal-length converging unit, initially converging object-side rays and correcting fundamental chromatic aberration; the rear lens group serves as a long-focal-length imaging unit, balancing aberrations and achieving high magnification and a flat image plane. Specifically, the first lens group has positive optical power and serves as the main object-side converging group, bearing a significant portion of the total optical power and being the core of the initial light convergence. The second lens group has positive optical power and serves as a relay converging group, receiving and finely controlling the rays converged by the first lens group. The third lens group has negative optical power and serves as an aberration balancing and magnification realization group, diverging rays to effectively balance the positive field curvature, spherical aberration, and coma generated by the front positive optical power group (the first and second lens groups), ensuring the image quality of the lens across the entire field of view; at the same time, through the reasonable configuration of its optical power and air gap, the overall length of the lens is effectively compressed while achieving high system magnification. The fourth lens group, g4, has positive optical power and serves as the image-side imaging and field-planning group. It converges light onto the image plane and ensures that the image-side principal ray is parallel to the optical axis, while correcting residual field curvature and residual distortion to achieve a flat image plane. This ultimately forms a high-magnification, high-resolution, and compact dual-telecentric lens, capable of meeting the application requirements of high-precision imaging and measurement scenarios.

[0018] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0021] Figure 1 This is a schematic diagram of the structure of a dual telecentric lens in an embodiment of this application;

[0022] Figure 2 This is an image bokeh curve of a dual telecentric lens in an embodiment of this application;

[0023] Figure 3 This is a distortion characteristic diagram of a dual telecentric lens in an embodiment of this application;

[0024] Figure 4 This is a diffraction modulation transfer function curve of a dual telecentric lens in an embodiment of this application;

[0025] Figure 5 This is a dot plot of a dual telecentric lens according to an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of another telecentric lens in the embodiments of this application;

[0027] Figure 7 This is an image bokeh curve of another dual telecentric lens in the embodiments of this application;

[0028] Figure 8 This is a distortion characteristic diagram of another telecentric lens in the embodiments of this application;

[0029] Figure 9 This is a diffraction modulation transfer function curve of another telecentric lens in this application embodiment;

[0030] Figure 10 This is a dot plot of another type of telecentric lens in the embodiments of this application;

[0031] Figure 11 This is a schematic diagram of an optical system structure in an embodiment of this application;

[0032] Figure 12 This is one of the structural schematic diagrams of an extinction unit in an optical system according to an embodiment of this application;

[0033] Figure 13This is a second schematic diagram of the structure of an extinction unit in an optical system according to an embodiment of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1-Double telecentric lens;

[0036] G1 - Front lens group;

[0037] g1 - First lens group; L1 - First prism; L2 - Second lens; L3 - Third lens; L4 - Fourth lens; L5 - Fifth lens; L6 - Sixth lens;

[0038] S1 - Aperture stop;

[0039] G2 - Rear lens group;

[0040] g2 - Second lens group; L7 - Seventh lens; L8 - Eighth lens; L9 - Ninth prism; L10 - Tenth lens;

[0041] g3 - Third lens group; L11 - Eleventh lens; L12 - Twelfth prism; L13 - Thirteenth lens;

[0042] g4 - Fourth lens group; L14 - Fourteenth lens; L15 - Fifteenth parallel plate;

[0043] C1 - First cemented lens; C2 - Second cemented lens; C3 - Third cemented lens;

[0044] 100 - Optical system; 10 - Illumination module; 20 - Optical imaging module; 30 - Photosensitive module;

[0045] 2-Extinction unit; 21-Lens barrel; 22-Extinction aperture; 211-Inner wall of the lens barrel; 212-Threaded structure; 221-Mounting part; 222-Shielding part; 223-Front surface; 224-Rear surface. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0048] 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 indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0049] This application provides a dual telecentric lens, an optical system, and a semiconductor device, which will be described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments of this application. Furthermore, the descriptions of each embodiment have their own emphasis; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments.

[0050] Please see Figure 1 The dual telecentric lens of this application includes: a front lens group G1, an aperture stop S1, and a rear lens group G2 arranged sequentially along the optical axis. The front lens group G1 is composed of a first lens group g1 with positive optical power, and the rear lens group G2 is composed of a second lens group g2 with positive optical power, a third lens group g3 with negative optical power, and a fourth lens group g4 with positive optical power. The first lens group g1 consists of a first prism L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 arranged sequentially along the optical axis. The second lens group g2 consists of a seventh lens L7, an eighth lens L8, a ninth prism L9, and a tenth lens L10 arranged sequentially along the optical axis. The third lens group g3 consists of an eleventh lens L11, a twelfth prism L12, and a thirteenth lens L13 arranged sequentially along the optical axis. The fourth lens group g4 consists of a fourteenth lens L14 and a fifteenth parallel plate L15 arranged sequentially along the optical axis. The focal length f of the front lens group G1 G1 The focal length f of the rear lens group G2 G2 The relation 0.014 < f is satisfied. G1 / f G2 <0.034. The total optical length TTL of a double telecentric lens and the focal length f of a double telecentric lens satisfy the following relationship: 0.42 < TTL / f < 1.65.

[0051] In this technical solution, the dual telecentric lens is divided into a front lens group G1 and a rear lens group G2, with the aperture stop S1 as the boundary. The optical path from the object plane to the aperture stop S1 is the front lens group G1, and the optical path from the aperture stop S1 to the image plane is the rear lens group G2. The aperture stop S1 is located at the image-side focal plane of the front lens group G1 and simultaneously at the object-side focal plane of the rear lens group G2 to ensure both object-side and image-side telecentricity. The focal length of the front lens group G1 is f. G1 The focal length of the rear lens group G2 is f. G2 The two satisfy the following relationship: 0.014 < f G1 / f G2 <0.034, indicating the focal length f of the visible rear lens group. G2 Much larger than the focal length f of the front lens group G1 (Focal length f of the front lens group) G1 Much smaller than the focal length f of the rear lens group G2 This enables high-magnification imaging. In this application, based on the focal length ratio of the aforementioned front and rear lens groups, the front lens group G1 serves as a short-focal-length converging unit, initially converging object-side rays and correcting aberrations such as fundamental chromatic aberration; the rear lens group G2 serves as a long-focal-length imaging unit, balancing aberrations and achieving high magnification and a flat image plane.

[0052] The front lens group G1 consists of the first lens group g1. The first lens group g1 has positive optical power and, as the object-side main converging group, bears a significant portion of the total optical power, serving as the core for the initial convergence of light rays. The rear lens group G2, from the object side to the image side, consists of the second lens group g2, the third lens group g3, and the fourth lens group g4. The second lens group g2 has positive optical power and, as the intermediate converging group, receives and finely controls the light rays converged by the first lens group g1, and works with the first lens group g1 to correct off-axis aberrations related to the pupil, such as astigmatism, coma, and distortion. The third lens group g3 has negative optical power and, as the aberration balancing and magnification realization group, diverges light rays to effectively balance aberrations such as positive field curvature generated by the front positive optical power groups (the first lens group g1 and the second lens group g2), ensuring image quality across the entire field of view. Simultaneously, through the rational configuration of its optical power and air gaps, it effectively compresses the overall lens length while achieving high system magnification. The fourth lens group g4 has positive optical power. As the image-side imaging and flat field group, it converges light to the image plane and ensures that the image-side principal ray is parallel to the optical axis, while correcting residual aberrations to achieve the goal of a flat image plane.

[0053] The total optical length of a double telecentric lens is TTL, and its total focal length is f. The two satisfy the following relationship: 0.42 < TTL / f < 1.65. Through the reasonable allocation of optical power between the front and rear lens groups, the ratio of the total optical length TTL to the total focal length f of the double telecentric lens can be kept within a low range while ensuring high magnification and double telecentric characteristics. This effectively avoids excessive redundancy in lens size and achieves the design goals of high magnification and lens miniaturization.

[0054] In some embodiments, the focal length f of the first lens group g1 g1 The total focal length f of the double telecentric lens satisfies the following relationship: 0.04 < |f g1 / f|<0.17. At 0.04<|f g1 When / f|<0.17, on the one hand, the powerful positive optical power in front provides ample space for aberration correction for the rear lens group, allowing the rear lens group to focus more on aberration balance rather than optical power contribution, thus improving the efficiency and effect of aberration correction; on the other hand, it makes the light strongly converged at the front of the lens (first lens group g1), which reduces the light aperture of the second lens group g2 and subsequent lens groups, thereby reducing the total material cost and overall weight of the lens.

[0055] The focal length f of the second lens group g2 g2 The focal length f of a double telecentric lens satisfies the following relationship: 0.01 < |f g2 / f|<0.08. At 0.01<|f g2 When / f|<0.08, on the one hand, it ensures that the second lens group g2 and the first lens group g1 form a high-performance composite positive group. The two work together to ensure that aberrations such as spherical aberration and coma are effectively corrected before the light enters the third lens group g3 with negative optical power, reducing the burden on subsequent lens groups. On the other hand, the second lens group g2 can smoothly receive and transmit the light beam from the first lens group g1, avoiding aberration deterioration caused by drastic changes in optical power between the first lens group g1 and the third lens group g3, and ensuring the stability of the optical path transmission.

[0056] The focal length f of the third lens group g3 g3 The focal length f of a double telecentric lens satisfies the following relationship: 0.002 < |f g3 / f|<0.016. At 0.002<|f g3When / f|<0.016, on the one hand, it ensures that the third lens group g3 has sufficient but not excessive negative optical power, which can accurately cancel the positive field curvature and other aberrations generated by the front positive optical power group (the first lens group g1 and the second lens group g2), which is conducive to achieving high resolution and a flat image plane; on the other hand, the third lens group g3 pushes the image-side principal point of the lens to the image-side side, which significantly compresses the total optical length TTL. This greatly reduces the physical volume of the lens while ensuring high magnification, and adapts to the demanding installation space requirements of semiconductor devices.

[0057] The focal length f of the fourth lens group g4 g4 The focal length f of a double telecentric lens satisfies the following relationship: 0.14 < |f g4 / f|<0.7. In 0.14<|f g4 When / f|<0.7, on the one hand, it ensures that the fourth lens group g4 is at a suitable optical power, so that it can accurately control the angle of the principal ray arriving at the image plane and ensure excellent image-side telecentricity; on the other hand, the fourth lens group g4 performs final processing on the imaging beam balanced by the third lens group g3, effectively correcting residual astigmatism, field curvature and distortion and other aberrations, ensuring consistent and clear imaging quality across the entire image plane.

[0058] Preferably, the focal length f of the first lens group g1 g1 The focal length f of the second lens group g2 is 19.2 ± 5% mm. g2 The focal length f of the third lens group g3 is 9.0±5% mm. g3 The focal length f of the fourth lens group g4 is 1.6±5%mm. g4 The diameter is 67.5~85.6mm.

[0059] Preferably, the lenses in the front lens group G1 and the rear lens group G2 are all spherical lenses. The first prism L1, the ninth prism L9, and the twelfth prism L12 have no optical power; both their object-side and image-side surfaces are flat. The second lens L2, the fourth lens L4, the seventh lens L7, and the tenth lens L10 have positive optical power and are biconvex lenses with convex object-side and convex image-side surfaces. The third lens L3 has negative optical power and is a meniscus negative lens with a convex object-side and concave image-side surface. The fifth lens L5 has positive optical power and is a meniscus positive lens with a concave object-side and convex image-side surface. The sixth lens L6 has negative optical power and is a meniscus negative lens with a concave object-side and convex image-side surface. The eighth lens L8, the eleventh lens L11, and the thirteenth lens L13 have negative optical power and are biconcave lenses with concave object-side and concave image-side surfaces. The fourteenth lens L14 has positive optical power and is a plano-convex lens with a flat object side and a convex image side; the fifteenth parallel plate L15 has no optical power and both its object side and image side are flat.

[0060] In this technical solution, firstly, the light beam from the object side is incident on the first prism L1 in the first lens group g1, where it undergoes its first optical path reversal. It then enters the second lens L2, where the diverging light rays from the object side are initially converged. The beam then passes through a first cemented lens C1 composed of a third lens L3 and a fourth lens L4, which is used to correct chromatic aberration. Afterward, the beam passes through a second cemented lens C2 composed of a fifth lens L5 and a sixth lens L6. This second cemented lens C2 assists in correcting chromatic aberration while compensating for spherical aberration and coma, laying a good image quality foundation for the beam to enter subsequent lens groups.

[0061] Next, the beam enters the third cemented lens C3, which consists of the seventh lens L7 and the eighth lens L8 in the second lens group g2, to finely compensate for the residual aberrations of the aforementioned lens group. Subsequently, the beam is incident on the ninth prism L9 for a second optical path deflection and enters the tenth lens L10, where the wavefront of the beam is shaped to ensure that the beam is directed towards the third lens group g3 in the optimal form.

[0062] Subsequently, the beam enters the eleventh lens L11 in the third lens group g3, exerting a strong divergence effect on the converging beam, effectively counteracting the positive field curvature accumulated by the front positive power group, and balancing spherical aberration and coma. Then, the beam is incident on the twelfth prism L12 for a third optical path reversal, and passes through the thirteenth lens L13, which further exerts a divergence effect on the converging beam. Together with the eleventh lens L11, this further shifts the image-side principal point of the lens, effectively compressing the lens's back working distance and overall length.

[0063] Finally, the beam enters the fourteenth lens L14 in the fourth lens group g4 for re-collimation and convergence, causing the principal ray to be incident on the image plane at an angle parallel to the optical axis and correcting residual field curvature and other aberrations. Ultimately, the beam passes through the fifteenth parallel plate L15, which acts as a protective glass, guiding the perfectly corrected beam to the image plane, forming a high-magnification, high-resolution final image with bi-telecentric characteristics.

[0064] Understandably, the first prism L1, the ninth prism L9, and the twelfth prism L12 are preferably beam-splitting prisms or reflecting prisms.

[0065] In some embodiments, the third lens L3 and the fourth lens L4 are cemented together to form a first cemented lens C1. The focal length f of the first cemented lens C1 is... C1 The total focal length f of the double telecentric lens satisfies the relationship: 0.06 < |f C1 / f|<0.28. The focal length f3 of the third lens L3 and the focal length f4 of the fourth lens L4 satisfy the relationship: 1.4 <f3 / f4<1.8。

[0066] The fifth lens L5 and the sixth lens L6 are cemented to each other to form a second cemented lens C2. The focal length f of the second cemented lens C2 C2 and the focal length f of the double telecentric lens satisfy the relationship: 0.05 < |f C2 / f| < 0.22. The focal length f5 of the fifth lens L5 and the focal length f6 of the sixth lens L6 satisfy the relationship: 1.3 < f5 / f6 < 1.7.

[0067] The seventh lens L7 and the eighth lens L8 are cemented to each other to form a third cemented lens C3. The focal length f of the third cemented lens C3 C3 and the focal length f of the double telecentric lens satisfy the relationship: 0.2 < |f C3 / f| < 0.75. The focal length f7 of the seventh lens L7 and the focal length f8 of the eighth lens L8 satisfy the relationship: 1.2 < f7 / f8 < 1.6.

[0068] In this technical solution, the first cemented lens C1 serves as a strong refractive power group, mainly used to correct the chromatic aberration of the system and lay a foundation for high resolution of the entire lens. The second cemented lens C2 also has a relatively strong refractive power. It works together with the first cemented lens C1 to further assist in correcting chromatic aberration, and also corrects spherical aberration and coma, ensuring uniform and sharp imaging quality from the center to the medium field region. The third cemented lens C3, as a weak refractive power group near the image plane, mainly corrects the residual aberration of the first cemented lens C1 and the second cemented lens C2 for fine compensation. The combined action of these three realizes the key to high-definition imaging of the entire field of view.

[0069] In some embodiments, the sagittal height SAG34 of the first cemented surface of the first cemented lens C1 along the optical axis direction and the total central thickness CT34 of the first cemented lens C1 on the optical axis satisfy the relationship: 0.18 < SAG34 / CT34 < 0.22. The sagittal height SAG56 of the second cemented surface of the second cemented lens C2 along the optical axis direction and the total central thickness CT56 of the second cemented lens C2 on the optical axis satisfy the relationship: 0.21 < SAG56 / CT56 < 0.25. The sagittal height SAG78 of the third cemented surface of the third cemented lens C3 along the optical axis direction and the total central thickness CT78 of the third cemented lens C3 on the optical axis satisfy the relationship: 0.02 < SAG78 / CT78 < 0.04.

[0070] In some embodiments, in the first cemented lens C1: the Abbe number Vd3 of the third lens L3 and the Abbe number Vd4 of the fourth lens L4 satisfy the relationship: Vd3 < Vd4. The refractive index Nd3 of the third lens L3 and the refractive index Nd4 of the fourth lens L4 satisfy the relationship: Nd3 > Nd4. In the second cemented lens C2: the Abbe number Vd5 of the fifth lens L5 and the Abbe number Vd6 of the sixth lens L6 satisfy the relationship: Vd5 > Vd6. The refractive index Nd5 of the fifth lens L5 and the refractive index Nd6 of the sixth lens L6 satisfy the relationship: Nd5 < Nd6. In the third cemented lens C3: the Abbe number Vd7 of the seventh lens L7 and the Abbe number Vd8 of the eighth lens L8 satisfy the relationship: Vd7 > Vd8. The refractive index Nd7 of the seventh lens L7 and the refractive index Nd8 of the eighth lens L8 satisfy the relationship: Nd7 < Nd8.

[0071] Preferably, the third lens L3 has a refractive index of 1.83±5% and an Abbe number of 37.2±5%; the fourth lens L4 has a refractive index of 1.50±5% and an Abbe number of 81.6±5%; the fifth lens L5 has a refractive index of 1.74±5% and an Abbe number of 45.0±5%; the sixth lens L6 has a refractive index of 1.80±5% and an Abbe number of 25.5±5%; the seventh lens L7 has a refractive index of 1.50±5% and an Abbe number of 81.6±5%; and the eighth lens L8 has a refractive index of 1.83±5% and an Abbe number of 37.2±5%.

[0072] Preferably, the thickness of the first cemented lens C1 is 5.6±0.5mm, the thickness of the second cemented lens C2 is 4.7±0.5mm, and the thickness of the third cemented lens C3 is 5.0±0.5mm.

[0073] Preferably, the focal length of the first cemented lens C1 is 32.0±5%mm, the focal length of the second cemented lens C2 is 24.8±5%mm, and the focal length of the third cemented lens C3 is 89.5±5%mm.

[0074] In some embodiments, in the third lens group g3, the focal lengths f11 of the eleventh lens L11 and f13 of the thirteenth lens L13 are related to the total focal length f of the double telecentric lens, satisfying: 0.03 < (f11 + f13) / f < 0.19. The total optical length TTL of the double telecentric lens and the focal length f of the third lens group g3 are... g3 The relation satisfies: 111 < TTL / f g3 <118. The air gap between the third lens group g3 and the fourth lens group g4 is 58.7±0.5mm.

[0075] In this technical solution, the total optical length TTL of the dual telecentric lens and the focal length f of the third lens group g3 are... g3 The ratio is 111 < TTL / fg3 Within the range of <118. Adjust the focal length f of the third lens group g3. g3 The value, if the focal length f of the third lens group g3 g3 If the focal length is too short (too strong a negative focal length), although the overall length can be significantly reduced, the third lens group g3 itself will produce high-order astigmatism and coma that are difficult to compensate for, and will excessively disturb the aberration balance of the system; conversely, if the focal length f of the third lens group g3 is too short, g3 If the focal length is too long (resulting in insufficient negative light focal length), it cannot effectively counteract the positive field curvature produced by the front positive light focal length group, and it also loses the ability to compress the overall length of the lens. Therefore, the focal length f of the third lens group g3 needs to be optimized. g3 The value is designed to configure an appropriate negative optical power for the third lens group g3, thereby simultaneously achieving excellent aberration correction and structural miniaturization. Furthermore, the air gap between the third lens group g3 and the fourth lens group g4 is set to 58.7 ± 0.5 mm, providing the necessary evolution distance for the beam diverged by the third lens group g3, allowing it to enter the fourth lens group g4 with optimal beam aperture and incident angle, ensuring efficient subsequent converging and high-quality imaging.

[0076] In some embodiments, the Abbe number Vd11 of the eleventh lens L11 and the Abbe number Vd13 of the thirteenth lens L13 satisfy the relationship: Vd11 = Vd13; the refractive index Nd11 of the eleventh lens L11 and the refractive index Nd13 of the thirteenth lens L13 satisfy the relationship: Nd11 = Nd13. The Abbe number Vd13 of the thirteenth lens L13 and the Abbe number Vd12 of the twelfth prism L12 satisfy the relationship: Vd13 < Vd12; the refractive index Nd13 of the thirteenth lens L13 and the refractive index Nd12 of the twelfth prism L12 satisfy the relationship: Nd13 > Nd12.

[0077] In this technical solution, both the eleventh lens L11 and the thirteenth lens L13 are made of high-refractive-index, low-dispersion materials, and both have negative optical power. Their identical material properties result in highly consistent dispersion behavior. As a whole, the axial chromatic aberration and magnification chromatic aberration generated in the optical path can form a synergistic suppression effect, controlling the contribution of both types of chromatic aberration within the system's allowable error threshold, thus avoiding the introduction of uncontrollable chromatic aberration variables in the critical aberration balance stage. The twelfth prism L12 is positioned between the eleventh lens L11 and the thirteenth lens L13. Although it has no optical power, its physical thickness introduces positive dispersion. Therefore, targeted compensation is achieved through the material properties and optical path position of L13, realizing precise matching and cancellation of dispersion values, further improving the overall imaging quality of the system.

[0078] Preferably, the eleventh lens L11 and the thirteenth lens L13 have a refractive index of 1.88±5% and an Abbe number of 40.9±5%. The twelfth prism L12 has a refractive index of 1.51±5% and an Abbe number of 64.2±5%.

[0079] Preferably, the thickness of the eleventh lens L11 is 2.0±0.5mm, the thickness of the twelfth prism L12 is 8.0mm, and the thickness of the thirteenth lens L13 is 2.0~5.0mm.

[0080] Preferably, the air gap between the eleventh lens L11 and the twelfth prism L12 is 6.5±0.5mm; and the air gap between the twelfth prism L12 and the thirteenth lens L13 is 1.9±0.5mm.

[0081] In some embodiments, in the fourth lens group g4, the focal length f14 of the fourteenth lens L14 and the focal length f of the double telecentric lens satisfy the relationship: 0.15 < f14 / f < 0.7.

[0082] In this technical solution, when the focal length f14 of the fourteenth lens L14 and the focal length f of the double telecentric lens satisfy the relationship: 0.15 < f14 / f < 0.7, on the one hand, it ensures that the beam diverged by the third lens group g3 can be effectively converged to the image plane by the fourteenth lens L14 with the optimal curvature, and precisely controls the propagation of the image-side principal ray at an angle parallel to the optical axis, thereby achieving strict image-side telecentric characteristics; on the other hand, within this range, it can ensure that the field curvature generated by the fourteenth lens L14 and the front lens group are mutually balanced, effectively neutralizing the residual field curvature in the system, thereby ensuring that the entire image plane achieves the best flatness and ensuring consistent high resolution from the center of the field of view to the edge.

[0083] In some embodiments, the Abbe number Vd14 of the fourteenth lens L14 and the Abbe number Vd15 of the fifteenth parallel plate L15 satisfy the relationship: Vd14 < Vd15. The refractive index Nd14 of the fourteenth lens L14 and the refractive index Nd15 of the fifteenth parallel plate L15 satisfy the relationship: Nd14 > Nd15.

[0084] Preferably, the fourteenth lens L14 has a refractive index of 1.83±5% and an Abbe number of 37.2±5%. The fifteenth parallel plate L15 has a refractive index of 1.51±5% and an Abbe number of 64.2±5%.

[0085] Preferably, the thickness of the fourteenth lens L14 is 2.9±0.5mm, and the thickness of the fifteenth parallel plate L15 is 2.0mm.

[0086] Preferably, the air gap between the fourteenth lens L14 and the fifteenth parallel plate L15 is 0.5±0.3mm.

[0087] Furthermore, in the technical solution of this application, preferably, the first prism L1 has a refractive index of 1.51±5% and an Abbe number of 64.2±5%. The second lens L2 has a refractive index of 1.80±5% and an Abbe number of 25.5±5%. The ninth prism L9 has a refractive index of 1.51±5% and an Abbe number of 64.2±5%. The tenth lens L10 has a refractive index of 1.80±5% and an Abbe number of 25.5±5%.

[0088] Preferably, the thickness of the first prism L1 is 12.0 mm, the thickness of the second lens L2 is 2.8 ± 0.5 mm, the thickness of the ninth prism L9 is 8.0 mm, and the thickness of the tenth lens L10 is 2.5 ± 0.5 mm.

[0089] Preferably, the air gap between the first prism L1 and the second lens L2 is 0.5±0.3mm, the air gap between the second lens L2 and the third lens L3 is 0.5±0.3mm, the air gap between the fourth lens L4 and the fifth lens L5 is 0.5±0.3mm, the air gap between the sixth lens L6 and the seventh lens L7 is 1.5±0.5mm, the air gap between the eighth lens L8 and the ninth prism L9 is 2.5±0.5mm, the air gap between the ninth prism L9 and the tenth lens L10 is 2.0±0.5mm, and the air gap between the tenth lens L10 and the eleventh lens L11 is 1.0±0.5mm.

[0090] In some embodiments, the entrance pupil diameter D of the double telecentric lens and the total focal length f of the double telecentric lens satisfy the relationship: 0.02≤D / 2f≤0.06, which can balance the light-gathering ability, theoretical diffraction-limited resolution and aberration correction difficulty.

[0091] In some embodiments, the total focal length f of the dual telecentric lens satisfies the relationship between the total optical length TTL of the dual telecentric lens and half the diagonal length ImgH of the effective pixel area of ​​the photosensitive module: 0.31≤f / (TTL×ImgH)≤1.13. This can minimize the total length of the optical system while ensuring high magnification, thus achieving a balance between high performance and high compactness.

[0092] Based on the foregoing description, the following detailed description is provided in conjunction with more specific embodiments and accompanying drawings.

[0093] Example 1

[0094] Table 1 below details the specific design parameters of each lens assembly of the dual telecentric lens in this embodiment, including the optical characteristics and geometric parameters of each component.

[0095] Table 1

[0096]

[0097] In this embodiment, such as Figure 1 As shown, the first prism L1 is a beam-splitting prism, the second lens L2 is a biconvex lens, the third lens L3 is a meniscus negative lens, the fourth lens L4 is a biconvex lens, the fifth lens L5 is a meniscus positive lens, the sixth lens L6 is a meniscus negative lens, the seventh lens L7 is a biconvex lens, the eighth lens L8 is a biconcave lens, the ninth prism L9 is a beam-splitting prism, the tenth lens L10 is a biconvex lens, the eleventh lens L11 is a biconcave lens, the twelfth prism L12 is a beam-splitting prism, the thirteenth lens L13 is a biconcave lens, the fourteenth lens L14 is a plano-convex lens, and the fifteenth parallel plate L15 is a parallel plate. Object is the object plane, S1 is the aperture stop, and Image is the image plane.

[0098] In this embodiment, the total focal length of the dual telecentric lens is f=405.2mm, the total optical length TTL=180mm, and the focal length of the front lens group is f. G1 =19.2mm, rear lens group focal length f G2 =666mm, f G1 / f G2 =0.029. The focal length f of the first lens group g1. g1 =19.2mm, the focal length f of the second lens group g2 g2 =9.0mm, the focal length f of the third lens group g3 g3 =1.6mm, the focal length f of the fourth lens group g4 g4 =67.5mm, |f g1 / f|=0.047,|f g2 / f|=0.022,|f g3 / f|=0.004,|f g4 / f|=0.166. |f C1 / f|=0.079, f3 / f4=1.69, |f C2 / f|=0.061, f5 / f6=1.5, |f C3 / f|=0.22, f7 / f8=1.4. SAG34 / CT34=0.20, SAG56 / CT56=0.23, SAG78 / CT78=0.037. (f12+f13) / f=0.033, TTL / f g3 =112.5. f14 / f=0.167. D / 2f=0.02, f / (TTL×ImgH)=1.13.

[0099] In this embodiment, the object-side numerical aperture of the dual telecentric lens is 0.1~0.2, the wavelength range is 400~800nm, and the object-side field of view diameter is greater than 1mm. The magnification of this dual telecentric lens is -20×, the object-side working distance is ≥20mm, and the image-side working distance is ≥25mm. This dual telecentric lens has an object-side and image-side dual telecentric structure: the principal rays of each field of view in the object side are approximately parallel to the optical axis and incident on the first lens group g1, with the angle between the principal rays and the optical axis less than or equal to 0.1°; the principal rays of each point in the image side are approximately parallel to the optical axis and exit onto the image plane, with the angle between the principal rays and the optical axis less than or equal to 0.1°, ensuring consistent telecentricity across the entire field of view.

[0100] Please see Figure 2 , Figure 2 The figure shows the astigmatism field curvature of this dual telecentric lens. The horizontal axis represents the focus offset (in mm), with positive and negative values ​​corresponding to the direction of image point offset relative to the ideal focal plane, and the magnitude of the value representing the degree of offset. The vertical axis represents the object height (in mm), with the dashed line T representing the meridional field curvature (T-field) and the solid line S representing the sagittal field curvature (S-field). As shown in the figure, within the 400nm~800nm ​​wavelength range, the field curvature deviation and the difference between the meridional and sagittal field curvatures (i.e., astigmatism) across the entire field of view are controlled within ±0.025mm. This indicates that the system has excellent field curvature and astigmatism correction effects, and the image spot outline is closer to the ideal geometry, ensuring consistent image sharpness across the entire field of view.

[0101] Please see Figure 3 , Figure 3 The figure shows the distortion characteristics of the dual telecentric lens. As can be seen from the figure, within the working wavelength range of 400nm~800nm ​​and the entire field of view, the absolute value of the distortion of the lens is ≤0.009%, and the distortion is symmetrically distributed. This indicates that the geometric deformation of the imaging pattern is extremely low, which can accurately reproduce the true size and shape of the object and meet the stringent requirements for distortion control in high-precision measurement scenarios.

[0102] Please see Figure 4 , Figure 4 This is a graph showing the diffraction modulation transfer function (MTF) curves of the dual telecentric lens. The horizontal axis represents spatial frequency (unit: lp / mm (period / mm)), and the vertical axis represents the MTF value (range 0~1). The curve labeled "F1:Diff.Limit" is the system's diffraction-limited MTF curve. The other curves correspond to the MTF curves under different field-of-view angles (or object heights) and designed object distances within the 400nm~800nm ​​working band and the full field of view. As shown in the graph, all MTF curves across the entire band and field of view highly coincide with the diffraction-limited curve, indicating that the optical transfer capability of this dual telecentric lens is close to the theoretical limit, exhibiting excellent image sharpness and detail reproduction, and possessing high-resolution imaging performance.

[0103] Please see Figure 5 , Figure 5 This is a dot plot of the dual telecentric lens. The horizontal axis represents the lateral offset within the image plane (unit: μm), and the vertical axis represents the field of view position (unit: mm). This dot plot corresponds to the 400nm~800nm ​​working wavelength band, the designed object distance, and the ideal focusing state (defocusing = 0). As shown in the figure, the imaging blur spots (centroid or root-mean-square radius) at each field of view position across the entire field of view are all within the Airy disk radius range of the corresponding wavelength, and the blur spot size is uniform. This indicates that the dual telecentric lens has sufficient aberration correction, excellent imaging spot concentration, and can achieve high-fidelity, high-resolution imaging effects. It can be understood that... Figure 5 The RMS (Root Mean Square) in the equation is used to quantitatively describe the dispersion of the light spot.

[0104] Example 2

[0105] Table 2 below details the specific design parameters of each lens assembly in the dual telecentric lens of this embodiment, including the optical characteristics and geometric parameters of each element. Except for the relevant parameters in Table 2, all other parameters are the same as in Embodiment 1, therefore the overlapping parts will not be repeated.

[0106] Table 2

[0107]

[0108] In this embodiment, such as Figure 6 As shown, the first prism L1 is a beam-splitting prism, the second lens L2 is a biconvex lens, the third lens L3 is a meniscus negative lens, the fourth lens L4 is a biconvex lens, the fifth lens L5 is a meniscus positive lens, the sixth lens L6 is a meniscus negative lens, the seventh lens L7 is a biconvex lens, the eighth lens L8 is a biconcave lens, the ninth prism L9 is a beam-splitting prism, the tenth lens L10 is a biconvex lens, the eleventh lens L11 is a biconcave lens, the twelfth prism L12 is a beam-splitting prism, the thirteenth lens L13 is a biconcave lens, the fourteenth lens L14 is a plano-convex lens, and the fifteenth parallel plate L15 is a parallel plate. Object is the object plane, S1 is the aperture stop, and Image is the image plane.

[0109] In this embodiment, the total focal length of the dual telecentric lens is f=123.4mm, the total optical length TTL=200mm, and the focal length of the front lens group is f. G1 =19.2mm, rear lens group focal length f G2 =996mm, f G1 / f G2 =0.019. The focal length f of the first lens group g1. g1=19.2mm, the focal length f of the second lens group g2 g2 =9.0mm, the focal length f of the third lens group g3 g3 =1.6mm, the focal length f of the fourth lens group g4 g4 =85.6mm, |f g1 / f|=0.156,|f g2 / f|=0.064,|f g3 / f|=0.014,|f g4 / f|=0.694. |f C1 / f|=0.26, f3 / f4=1.69, |f C2 / f|=0.20, f5 / f6=1.5, |f C3 / f|=0.73, f7 / f8=1.4. SAG34 / CT34=0.20, SAG56 / CT56=0.23, SAG78 / CT78=0.037. (f12+f13) / f=0.188, TTL / f g3 =117.6. f14 / f=0.68. D / 2f=0.06, f / (TTL×ImgH)=0.31.

[0110] In this embodiment, the object-side numerical aperture of the dual telecentric lens is 0.1~0.2, the wavelength range is 400~800nm, and the object-side field of view diameter is greater than 1mm. The magnification of this dual telecentric lens is -20×, the object-side working distance is ≥20mm, and the image-side working distance is ≥25mm. This dual telecentric lens has an object-side and image-side dual telecentric structure: the principal rays of each field of view in the object side are approximately parallel to the optical axis and incident on the first lens group g1, with the angle between the principal rays and the optical axis less than or equal to 0.1°; the principal rays of each point in the image side are approximately parallel to the optical axis and exit onto the image plane, with the angle between the principal rays and the optical axis less than or equal to 0.1°, ensuring consistent telecentricity across the entire field of view.

[0111] Please see Figure 7 , Figure 7 The figure shows the astigmatism field curvature of this dual telecentric lens. The horizontal axis represents the focus offset (in mm), with positive and negative values ​​corresponding to the direction of image point offset relative to the ideal focal plane, and the magnitude of the value representing the degree of offset. The vertical axis represents the object height (in mm), with the dashed line T representing the meridional field curvature (T-field) and the solid line S representing the sagittal field curvature (S-field). As shown in the figure, within the 400nm~800nm ​​wavelength range, the field curvature deviation and the difference between the meridional and sagittal field curvatures (i.e., astigmatism) across the entire field of view are controlled within ±0.025mm. This indicates that the system has excellent field curvature and astigmatism correction effects, and the image spot outline is closer to the ideal geometry, ensuring consistent image sharpness across the entire field of view.

[0112] Please see Figure 8 , Figure 8 The figure shows the distortion characteristics of the dual telecentric lens. As can be seen from the figure, the absolute value of the distortion of the lens is ≤0.016% in the working wavelength range of 400nm~800nm ​​and the entire field of view. This indicates that the geometric deformation of the imaging pattern is extremely low, which can accurately restore the true size and shape of the object and meet the stringent requirements for distortion control in high-precision measurement scenarios.

[0113] Please see Figure 9 , Figure 9 This is a graph showing the diffraction modulation transfer function (MTF) curves of the dual telecentric lens. The horizontal axis represents spatial frequency (unit: lp / mm (period / mm)), and the vertical axis represents the MTF value (range 0~1). The curve labeled "F1:Diff.Limit" is the system's diffraction-limited MTF curve. The other curves correspond to the MTF curves under different field-of-view angles (or object heights) and designed object distances within the 400nm~800nm ​​working band and the full field of view. As shown in the graph, all MTF curves across the entire band and field of view highly coincide with the diffraction-limited curve, indicating that the optical transfer capability of this dual telecentric lens is close to the theoretical limit, exhibiting excellent image sharpness and detail reproduction, and possessing high-resolution imaging performance.

[0114] Please see Figure 10 , Figure 10 This is a dot plot of the dual telecentric lens. The horizontal axis represents the lateral offset within the image plane (unit: μm), and the vertical axis represents the field of view position (unit: mm). This dot plot corresponds to the 400nm~800nm ​​working wavelength band, the designed object distance, and the ideal focusing state (defocusing = 0). As shown in the figure, the imaging blur spots (centroid or root-mean-square radius) at each field of view position across the entire field of view are all within the Airy disk radius range of the corresponding wavelength, and the blur spot size is uniform. This indicates that the dual telecentric lens has sufficient aberration correction, excellent imaging spot concentration, and can achieve high-fidelity, high-resolution imaging effects. It can be understood that... Figure 10 The RMS (Root Mean Square) in the equation is used to quantitatively describe the dispersion of the light spot.

[0115] Please see Figure 11 In embodiments of this application, an optical system 100 is also provided, comprising: an illumination module 10 for emitting an illumination beam to illuminate an object under test; an optical imaging module 20 having a dual telecentric lens 1 as described in any of the above technical solutions, for receiving the beam from the object under test; and a photosensitive module 30 disposed at the image plane position of the optical imaging module for receiving the imaging beam and converting the light signal into an electrical signal for imaging. The optical imaging module 20 further includes an extinction unit 2 for absorbing or blocking non-imaging light.

[0116] Please see Figure 12 The extinction unit 2 consists of a lens barrel 21 and multiple extinction stops 22 installed on the inner wall 211 of the lens barrel. The extinction stops 22 are positioned between the third lens group g3 and the fourth lens group g4, specifically between the thirteenth lens L13 and the fourteenth lens L14, to absorb or block non-imaging light generated between the aforementioned lens groups, thereby suppressing stray light. The installation positions and apertures of the multiple extinction stops 22 can be specifically designed according to the actual stray light distribution of the system. By finely adjusting the position of each extinction stop 22 along the optical axis, it can be precisely positioned in the area between the inner walls of the lens barrel 21 where stray light reflection is most concentrated. This maximizes the interception and absorption of stray light reflected multiple times, altering its propagation path, thereby significantly improving the system's stray light suppression capability and enhancing the imaging signal-to-noise ratio.

[0117] Please see Figure 13 The extinction stop 22 includes a mounting part 221 and a blocking part 222 connected thereto. The mounting part 221 is fixed to the lens barrel 21 via a threaded structure 212 on the inner wall 211 of the lens barrel. The blocking part 222 extends inward from the mounting part 221 in a direction perpendicular to the optical axis of the double telecentric lens 1. By setting the extinction stop 22, its blocking part 222 can effectively block stray light propagating at a large angle. When such light is incident on the front surface 223 of the blocking part 222, which has undergone special extinction treatment, most of its energy is absorbed, and only a very weak reflected light returns to the front lens barrel space at a similar angle. Its energy is rapidly attenuated in subsequent reflections and cannot propagate to the image plane. Meanwhile, stray light incident at a small angle may bypass the edge of the current extinction stop 22 and continue to propagate along the optical axis. The remaining stray light at a small angle will be intercepted and absorbed again by the extinction stop 22 at the rear end, thus forming a full-process, multi-level suppression system covering stray light at both large and small angles, ensuring that stray light cannot ultimately reach the sensor imaging surface.

[0118] In some embodiments of this application, a semiconductor device is also provided, which includes a telecentric lens as described in any of the above technical solutions, or an optical system as described in any of the above technical solutions. Since the telecentric lens or optical system in this semiconductor device has the same technical features as the aforementioned telecentric lens or optical system, both can solve the same technical problems and achieve the same technical effects.

[0119] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0120] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims. Furthermore, specific examples have been used in the specification to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application, and the content of this specification should not be construed as a limitation of this application.

Claims

1. A double telecentric lens, characterized in that, include: The front lens group, aperture stop, and rear lens group are arranged sequentially along the optical axis. The front lens group includes a first lens group with positive optical power; The rear lens group includes a second lens group with positive optical power, a third lens group with negative optical power, and a fourth lens group with positive optical power. The focal length f of the front lens group G1 The focal length f of the rear lens group G2 The relation 0.014 < f is satisfied. G1 / f G2 <0.034; The total optical length TTL of the dual telecentric lens and the focal length f of the dual telecentric lens satisfy the following relationship: 0.42 < TTL / f < 1.65; The focal length f of the first lens group g1 The focal length f of the aforementioned telecentric lens satisfies the following relationship: 0.04 < |f g1 / f|<0.17; The focal length f of the second lens group g2 The focal length f of the aforementioned telecentric lens satisfies the following relationship: 0.01 < |f g2 / f|<0.08; The focal length f of the third lens group g3 The focal length f of the aforementioned telecentric lens satisfies the following relationship: 0.002 < |f g3 / f|<0.016; The focal length f of the fourth lens group g4 The focal length f of the aforementioned telecentric lens satisfies the following relationship: 0.14 < |f g4 / f|<0.

7.

2. The double telecentric lens according to claim 1, characterized in that, The first lens group includes a first prism, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical axis. The second lens group includes a seventh lens, an eighth lens, a ninth prism, and a tenth lens arranged sequentially along the optical axis. The third lens group includes an eleventh lens, a twelfth prism, and a thirteenth lens arranged sequentially along the optical axis. The fourth lens group includes a fourteenth lens and a fifteenth parallel plate arranged sequentially along the optical axis.

3. The dual telecentric lens according to claim 2, characterized in that, The third lens and the fourth lens are cemented together to form a first cemented lens, and the focal length f of the first cemented lens is... C1 The focal length f of the dual telecentric lens satisfies the following relationship: 0.06 < |f C1 / f|<0.28; The focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy the following relationship: 1.4 <f3 / f4<1.8; The fifth lens and the sixth lens are cemented together to form a second cemented lens, the focal length f of the second cemented lens. C2 The focal length f of the aforementioned telecentric lens satisfies the following relationship: 0.05 < |f C2 / f|<0.22; The focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy the following relationship: 1.3 <f5 / f6<1.7; The seventh lens and the eighth lens are cemented together to form a third cemented lens, the focal length f of which is... C3 The focal length f of the aforementioned telecentric lens satisfies the following relationship: 0.2 < |f C3 / f|<0.75; The focal length f7 of the seventh lens and the focal length f8 of the eighth lens satisfy the following relationship: 1.2 <f7 / f8<1.6。 4. The double telecentric lens according to claim 3, characterized in that, The sagitta SAG34 of the first cemented surface along the optical axis and the total center thickness CT34 of the first cemented lens along the optical axis satisfy the following relationship: 0.18 <SAG34 / CT34<0.22; The sagitta SAG56 of the second cemented surface along the optical axis and the total center thickness CT56 of the second cemented lens along the optical axis satisfy the following relationship: 0.21 <SAG56 / CT56<0.25; The sag SAG78 of the third cemented surface along the optical axis of the third cemented lens and the total center thickness CT78 of the third cemented lens along the optical axis satisfy the following relationship: 0.02 <SAG78 / CT78<0.04。 5. The dual telecentric lens according to claim 2, characterized in that, The third lens is a meniscus negative lens, and the fourth lens is a biconvex lens; The fifth lens is a positive meniscus lens, and the sixth lens is a negative meniscus lens; The seventh lens is a biconvex lens, and the eighth lens is a biconcave lens.

6. The dual telecentric lens according to claim 2, characterized in that, The Abbe number Vd3 of the third lens and the Abbe number Vd4 of the fourth lens satisfy the relationship: Vd3 < Vd4; the refractive index Nd3 of the third lens and the refractive index Nd4 of the fourth lens satisfy the relationship: Nd3 > Nd4. The Abbe number Vd5 of the fifth lens and the Abbe number Vd6 of the sixth lens satisfy the relationship: Vd5 > Vd6; the refractive index Nd5 of the fifth lens and the refractive index Nd6 of the sixth lens satisfy the relationship: Nd5 < Nd6. The Abbe number Vd7 of the seventh lens and the Abbe number Vd8 of the eighth lens satisfy the relationship: Vd7 > Vd8; the refractive index Nd7 of the seventh lens and the refractive index Nd8 of the eighth lens satisfy the relationship: Nd7 < Nd8.

7. The dual telecentric lens according to claim 2, characterized in that, In the third lens group, the eleventh and thirteenth lenses are biconcave lenses; The relationship between the focal length f11 of the eleventh lens, the focal length f13 of the thirteenth lens, and the focal length f of the double telecentric lens satisfies: 0.03 < (f11 + f13) / f < 0.19; The total optical length TTL of the double telecentric lens and the focal length f of the third lens group g3 The relation satisfies: 111 < TTL / f g3 <118; The air gap between the third lens group and the fourth lens group is 58.7 ± 0.5 mm.

8. The dual telecentric lens according to claim 2, characterized in that, The Abbe number Vd11 of the eleventh lens and the Abbe number Vd13 of the thirteenth lens satisfy the following relationship: Vd11 = Vd13; The refractive index Nd11 of the eleventh lens and the refractive index Nd13 of the thirteenth lens satisfy the following relationship: Nd11 = Nd13; The Abbe number Vd13 of the thirteenth lens and the Abbe number Vd12 of the twelfth prism satisfy the following relationship: Vd13 < Vd12; The refractive index Nd13 of the thirteenth lens and the refractive index Nd12 of the twelfth prism satisfy the relationship: Nd13 > Nd12.

9. The double telecentric lens according to claim 2, characterized in that, In the fourth lens group, the fourteenth lens is a plano-convex lens with a flat object side and a convex image side. The focal length f14 of the fourteenth lens and the focal length f of the double telecentric lens satisfy the following relationship: 0.15 < f14 / f < 0.

7.

10. The double telecentric lens according to claim 2, characterized in that, The Abbe number Vd14 of the fourteenth lens and the Abbe number Vd15 of the fifteenth parallel plate satisfy the following relationship: Vd14 < Vd15; The refractive index Nd14 of the fourteenth lens and the refractive index Nd15 of the fifteenth parallel plate satisfy the relationship: Nd14 > Nd15.

11. The double telecentric lens according to claim 1, characterized in that, The entrance pupil diameter D of the double telecentric lens and the focal length f of the double telecentric lens satisfy the following relationship: 0.02≤D / 2f≤0.06; The focal length f of the dual telecentric lens satisfies the following relationship with the total optical length TTL of the dual telecentric lens and half the diagonal length ImgH of the effective pixel area of ​​the photosensitive module: 0.31≤f / (TTL×ImgH)≤1.

13.

12. An optical system, characterized in that, include: An illumination module is used to emit an illumination beam to illuminate the object under test; An optical imaging module having a dual telecentric lens as described in any one of claims 1 to 11 for receiving a light beam from the object under test; A photosensitive module, located at the image plane of the optical imaging module, is used to receive the imaging beam and convert the optical signal into an electrical signal for imaging. The optical imaging module also includes an extinction unit for absorbing or blocking non-imaging light.

13. The optical system according to claim 12, characterized in that, The extinction unit consists of a lens barrel and multiple extinction stops installed on the inner wall of the lens barrel; The extinction aperture includes a mounting part and a blocking part connected thereto; The mounting part is fixed to the lens barrel by a threaded structure on the inner wall of the lens barrel; The blocking portion extends inward from the mounting portion in a direction perpendicular to the optical axis of the dual telecentric lens to absorb or block non-imaging light.

14. A semiconductor device, characterized in that, include: The double telecentric lens as described in any one of claims 1 to 11, or the optical system as described in any one of claims 12 to 13.

Images