High-magnification achromatic telecentric lens and optical system thereof

Abstract

The utility model relates to the technical field of optical lenses, and discloses a high-magnification achromatic telecentric lens and an optical system thereof. The optical system comprises a first lens G1 with positive focal power, a second lens G2 with negative focal power, a third lens G3 with positive focal power, a fourth lens G4 with negative focal power, a fifth lens G5 with positive focal power, a sixth lens G6 with negative focal power, a seventh lens G7 with positive focal power and a diaphragm T which are sequentially arranged from an object side to an image side, the system comprises a first lens G8 with negative focal power, an eighth lens G8 with negative focal power, a ninth lens G9 with negative focal power, a tenth lens G10 with positive focal power and an eleventh lens G11 with positive focal power. According to the optical system of the double telecentric structure provided by the utility model, the amplification factor can reach more than four times, the numerical aperture NA can reach 0.16, and the resolution of the microscopic level of 2 microns can be realized; and the maximum imaging surface can reach phi 44 mm.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical lens technical field especially relates to a high magnification achromatic telecentric lens and optical system thereof. BACKGROUND

[0002] In the high-precision detection field of semiconductor, mini LED (Light-Emitting Diode Light), FPD (Flat Panel Display) and pan-semiconductor, a high magnification telecentric lens supporting high-pixel large target camera is needed, but the target surface that the existing high magnification telecentric lens can support is concentrated below 1.1 inch, which does not meet the detection needs of such high-precision detection field; in addition, the achromatic wavelength band of the existing high magnification telecentric lens is often incompatible with the 436nm blue-violet light wavelength band, which may cause chromatic aberration problems.

[0003] Therefore, for those skilled in the art, how to design a high magnification achromatic telecentric lens with a large imaging target surface to cooperate with full-frame cameras, 8k5μm line scanning cameras and the like, while improving the chromatic aberration problems of the existing high magnification telecentric lens, has become a technical problem to be solved in the field.

[0004] The above information is given as background information only to assist with an understanding of the present disclosure, and does not constitute a admission that any of the above information is applicable as prior art with regard to the present disclosure. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a high magnification achromatic telecentric lens and optical system thereof to solve or at least partially solve the technical problems existing in the prior art.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] In a first aspect, the utility model provides an optical system of a high magnification achromatic telecentric lens, comprising a first lens G1 with positive refractive power, a second lens G2 with negative refractive power, a third lens G3 with positive refractive power, a fourth lens G4 with negative refractive power, a fifth lens G5 with positive refractive power, a sixth lens G6 with negative refractive power, a seventh lens G7 with positive refractive power, a stop T, an eighth lens G8 with negative refractive power, a ninth lens G9 with negative refractive power, a tenth lens G10 with positive refractive power and an eleventh lens G11 with positive refractive power arranged in order from object side to image side;Wherein, the first lens G1 to the seventh lens G7 form a front lens group, the eighth lens G8 to the tenth lens G10 form a rear lens group, and the stop T is placed at the focal point of the front lens group to form a telecentric architecture;

[0008] The working distance of the optical system is WD, and the numerical aperture of the optical system is NA, WD and NA satisfy the relationship: NA*WD<13.

[0009] Optionally, the focal length of the front lens group is f 100 , the focal length of the rear lens group is f 200 , f 100 and f 200 satisfy the relationship: 0.4<|f 200 / f 100 |<1.

[0010] Optionally, the second lens G2, the third lens G3 and the fourth lens G4 form a triple cemented lens U1, and the fifth lens G5 and the sixth lens G6 form a double cemented lens U2.

[0011] The focal length of the first lens G1 is f1, the focal length of the triple cemented lens U1 is f U1 , the focal length of the double cemented lens U2 is f U2 , and the focal length of the seventh lens G7 is f7.

[0012] f1 and f 100 satisfy the relationship: 0.35<|f 100 / f1|<0.95.

[0013] f U1 and f 100 satisfy the relationship: |f 100 / f U1 |<0.2.

[0014] f U2 and f 100 satisfy the relationship: |f 100 / f U2 |<0.26.

[0015] f7 and f 100 satisfy the relationship: 0.3<|f 100 / f7|<0.9.

[0016] Optionally, the refractive index of the third lens G3 is n3, and the Abbe number is v3, which satisfy the relationship: 1.42<n3<1.65; 60<v3<95.

[0017] The refractive index of the fifth lens G5 is n5, and the Abbe number is v5, which satisfy the relationship: 1.42<n5<1.65; 60<v5<95.

[0018] Optionally, the ninth lens G9 and the tenth lens G10 form a double cemented lens U3.

[0019] The focal length of the eighth lens G8 is f8, the focal length of the doublet lens U3 is f U3 , the focal length of the eleventh lens G11 is f 11 ;

[0020] f8 and f 200 satisfy the relationship: 0.45<|f8 / f 200 |<0.9;

[0021] f U3 and f 200 satisfy the relationship: |f 200 / f U3 |<0.5;

[0022] f 11 and f 200 satisfy the relationship: 2.5<|f 11 / f 200 |<5.

[0023] Optionally, the first lens G1 to the eleventh lens G11 are all glass spherical lenses.

[0024] Optionally, the first lens G1, the third lens G3, the fifth lens G5, the seventh lens G7, the tenth lens G10 and the eleventh lens G11 are all double convex lenses, the second lens G2, the fourth lens G4 and the sixth lens G6 are all meniscus lenses, and the eighth lens G8 is a double concave lens.

[0025] Optionally, the optical axes of all the glass spherical lenses are on a predetermined optical axis.

[0026] Optionally, the aperture of the diaphragm T is a circular hole, and the center of the circular hole is on the predetermined optical axis.

[0027] In the second aspect, the utility model provides a kind of high magnification achromatic telecentric lens, including the optical system of a kind of high magnification achromatic telecentric lens as described above.

[0028] Compared with prior art, the utility model has the following beneficial effects:

[0029] The high magnification achromatic telecentric lens and the optical system thereof provided by the utility model can achieve a magnification of more than 4 times, a numerical aperture NA of 0.16, and a resolution of 2 microns, and can achieve a maximum imaging area of Φ44mm, which can be matched with a 6500W pixel, a 38mm diagonal camera and an 8k5μm line scanning camera, and can meet the requirements of high-precision detection fields such as semiconductors, mini-LEDs, FPDs and general semiconductors.

[0030] The present application has other characteristics and advantages, which will be apparent from the accompanying drawings and the detailed description that follows, or will be set forth in the accompanying drawings and the detailed description that follows, which together serve to explain the specific principles of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0032] Figure 1 is a structural schematic diagram of an optical system of a high-magnification achromatic telecentric lens provided by the first embodiment of the present application.

[0033] Figure 2 is an image-side MTF curve diagram of the optical system of the high-magnification achromatic telecentric lens provided by the first embodiment of the present application.

[0034] Figure 3 is a polychromatic light focal point displacement curve diagram of the optical system of the high-magnification achromatic telecentric lens provided by the first embodiment of the present application.

[0035] Figure 4 is a distortion diagram of the optical system of the high-magnification achromatic telecentric lens provided by the first embodiment of the present application.

[0036] Figure 5 is a structural schematic diagram of an optical system of a high-magnification achromatic telecentric lens provided by the second embodiment of the present application.

[0037] Figure 6 is an image-side MTF curve diagram of the optical system of the high-magnification achromatic telecentric lens provided by the second embodiment of the present application.

[0038] Figure 7 is a polychromatic light focal point displacement curve diagram of the optical system of the high-magnification achromatic telecentric lens provided by the second embodiment of the present application.

[0039] Figure 8 is a distortion diagram of the optical system of the high-magnification achromatic telecentric lens provided by the second embodiment of the present application. DETAILED DESCRIPTION

[0040] To explain possible application scenarios, technical principles, specific implementation schemes, and the purposes and effects of the present application in detail, the following embodiments are described in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0041] In this paper, the term "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The term "embodiment" appearing at various places in the specification does not necessarily refer to the same embodiment, and does not particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, each technical feature mentioned in each embodiment can be combined in any way to form a corresponding implementable technical solution.

[0042] Unless otherwise defined, the meaning of the technical terms used herein is the same as that generally understood by those skilled in the art to which the present application belongs; the use of related terms herein is only for the purpose of describing specific embodiments, and is not intended to limit the present application.

[0043] In the description of the present application, the phrase "and / or" is a description of the logical relationship between the objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this paper generally represents that the associated objects before and after are a "or" logical relationship.

[0044] In the present application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantity, primary and secondary or order relationship between the entities or operations.

[0045] Without more limitations, in the present application, the phrases "include", "contain", "have" or other similar expressions used in the sentence are intended to cover non-exclusive inclusion, and these expressions do not exclude the presence of other elements in the process, method or product including the described elements, so that the process, method or product including a series of elements can not only include those limited elements, but also include other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0046] As the same understanding in the "Examination Guidelines", in the present application, "greater than", "less than", "exceed" and the like are understood as not including the number; "above", "below", "within" and the like are understood as including the number. In addition, in the description of the embodiments of the present application, the meaning of "multiple" is more than two (including two), and similar expressions related to "multiple" are also understood in this way, for example, "multiple groups", "multiple times" and the like, unless otherwise explicitly specified.

[0047] In the description of the embodiments of the present application, the spatially related expressions used, such as "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiment or the drawing, and are only for the convenience of describing the specific embodiments of the present application or for the reader to understand, and do not indicate or imply that the indicated device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0048] Unless otherwise explicitly specified or limited, in the description of the embodiments of the present application, the terms "mount", "connect", "connect", "fix", "set" and the like should be broadly understood. For example, the "connection" can be fixed connection, or detachable connection, or integral setting; it can be mechanical connection, or electrical connection, or communication connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication or interaction relationship between two elements. For those skilled in the art to which the present application belongs, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0049] Embodiment one:

[0050] Please refer to Figure 1 , Figure 1 is a structural schematic diagram of an optical system of a high-magnification achromatic telecentric lens provided by the embodiment one of the present application;

[0051] As Figure 1 shown, the optical system comprises:

[0052] The optical system comprises, arranged in order from the object side to the image side, a first lens G1 having positive refractive power, a second lens G2 having negative refractive power, a third lens G3 having positive refractive power, a fourth lens G4 having negative refractive power, a fifth lens G5 having positive refractive power, a sixth lens G6 having negative refractive power, a seventh lens G7 having positive refractive power, a stop T, an eighth lens G8 having negative refractive power, a ninth lens G9 having negative refractive power, a tenth lens G10 having positive refractive power, and an eleventh lens G11 having positive refractive power; wherein the first lens G1 to the seventh lens G7 form a front lens group 100, the eighth lens G8 to the tenth lens G10 form a rear lens group 200, and the stop T is placed at a focal point of the front lens group 100, forming a telecentric structure.

[0053] The working distance of the optical system is WD, and the numerical aperture of the optical system is NA, and WD and NA satisfy the relationship: NA x WD < 13.

[0054] Further, the focal length of the front lens group 100 is f 100 , the focal length of the rear lens group 200 is f 200 , and f 100 and f 200 satisfy the relationship: 0.4 < |f 200 / f 100 | < 1.

[0055] Specifically, the second lens G2, the third lens G3, and the fourth lens G4 form a triple cemented lens U1, and the fifth lens G5 and the sixth lens G6 form a double cemented lens U2.

[0056] The focal length of the first lens G1 is f1, the focal length of the triple cemented lens U1 is f U1 , the focal length of the double cemented lens U2 is f U2 , and the focal length of the seventh lens G7 is f7.

[0057] f1 and f 100 satisfy the relationship: 0.35 < |f 100 / f1 | < 0.95.

[0058] f U1 and f 100 satisfy the relationship: |f 100 / f U1 | < 0.2.

[0059] f U2 and f 100 satisfy the relationship: |f 100 / f U2 | < 0.26.

[0060] f7 and f 100 satisfy the relationship: 0.3 < |f100 f7 < 0.9.

[0061] Specifically, the third lens G3 has a refractive index n3 and an Abbe number v3, and satisfies the relationship: 1.42 < n3 < 1.65; 60 < v3 < 95.

[0062] The fifth lens G5 has a refractive index n5 and an Abbe number v5, and satisfies the relationship: 1.42 < n5 < 1.65; 60 < v5 < 95.

[0063] Specifically, the ninth lens G9 and the tenth lens G10 form a double cemented lens U3.

[0064] The eighth lens G8 has a focal length f8, and the double cemented lens U3 has a focal length f U3 The eleventh lens G11 has a focal length f 11 .

[0065] f8 and f 200 satisfy the relationship: 0.45 < |f8 / f 200 | < 0.9.

[0066] f U3 and f 200 satisfy the relationship: |f 200 / f U3 | < 0.5.

[0067] f 11 and f 200 satisfy the relationship: 2.5 < |f 11 / f 200 | < 5.

[0068] In the embodiment, the reasonable distribution of the interval and the optical power of the positive and negative lenses of the front lens group 100 can form small spherical aberration and field curvature, reduce the tolerance sensitivity, and maintain a suitable lens shape, which is easy to process. The combination of the three cemented lenses U1 and the double cemented lens U2 in the negative-positive-negative form can well correct the chromatic aberration of the system. The third lens G3 and the fifth lens G5 select materials with low dispersion to further enhance the chromatic aberration correction effect, so that the achromatic waveband of the system is compatible to 436 nm wavelength. The double cemented lens U3 in the rear lens group 200 is a new type of cemented lens, which can balance the field curvature of the lens optical system, and the cemented surface thereof can correct astigmatism and distortion. The lens group 100 has positive optical power, and the eighth lens with negative optical power is separated by a certain distance, which is also beneficial to correct spherical aberration and field curvature.

[0069] In the embodiment, the first lens G1 to the eleventh lens G11 are all glass spherical lenses.

[0070] The first lens G1, the third lens G3, the fifth lens G5, the seventh lens G7, the tenth lens G10 and the eleventh lens G11 are all double convex lenses, the second lens G2, the fourth lens G4 and the sixth lens G6 are all meniscus lenses, and the eighth lens G8 is a double concave lens.

[0071] In this embodiment, the optical axes of all the glass spherical lenses are on the predetermined optical axis.

[0072] The aperture of the diaphragm T is a circular hole, and the center of the circular hole is on the predetermined optical axis.

[0073] It can be understood that the aperture value of the diaphragm T needs to be adjusted according to the specific application scenario.

[0074] To verify whether the above optical system meets the design purpose, the following is a specific test example given according to the above settings of this embodiment:

[0075] In this test example, the lens data of the optical system is shown in Table 1 as follows:

[0076] Table 1

[0077]

[0078]

[0079] It should be noted that in Table 1, the "front surface" corresponds to the left surface of the corresponding lens or lens group in Figure 1 , and the "back surface" corresponds to the right surface of the corresponding lens or lens group in Figure 1 ; or it can be understood that: the object side is on the left side, the image side (or image plane) is on the right side, the side surface close to the object side is the "front surface", and the side surface close to the image side is the "back surface". Figure 1 Figure 1

[0080] In this test example, the combined focal length f 100＝ of the front lens group 100 is 58mm; the focal length f1 of the first lens G1 is 88mm; the focal length f U1 of the three-cemented lens group U1 is -408mm; the focal length f U2 of the double-cemented lens U2 is 279mm; the focal length f7 of the seventh lens G7 is 101mm; the combined focal length f 200 of the rear lens group 200 is -41mm; the focal length f8 of the eighth lens G8 is -28mm; the focal length f U3 of the double-cemented lens U3 is 165mm; the focal length f 11 of the eleventh lens G11 is 125mm.

[0081] ​​Substitute the above values into each relationship to obtain respectively:

[0082] |f 200 / f 100 |=0.707,|f 100 / f1|=0.659,|f 100 / f U1 |=0.142,|f 100 / f U2 |=0.208,|f 100 / f7|=0.574,|f8 / f 200 |=0.683,|f 200 / f U3 |=0.248,|f 11 / f 200 |=3.05。

[0083] Therefore, the relevant relationship of the embodiment is satisfied, that is:

[0084] 0.4<|f 200 / f 100 |<1,0.35<|f 100 / f1|<0.95,|f 100 / f U1 |<0.2,|f 100 / f U2 |<0.26,0.3<|f 100 / f7|<0.9,0.45<|f8 / f 200 |<0.9,|f 200 / f U3 |<0.5,2.5<|f 11 / f 200 |<5。

[0085] In the test example, the optical parameters of the optical system are shown in Table Two as follows:

[0086] Table Two

[0087] Working distance WD 71 mm Numerical aperture NA 0.164 Resolution 2.2 microns Magnification 4x Target surface Φ 44 mm Telecentricity <0.1° Distortion 0.05％

[0088] Wherein, the calculation formula of the resolution is 0.65*λ / NA, λ is wavelength (0.55 microns in the embodiment).

[0089] Please refer to Figure 2 , Figure 3 and Figure 4 , Figure 2 is an image-side MTF (Modulation Transfer Function) curve of the optical system of the high-magnification achromatic telecentric lens provided in Embodiment One of the utility model,Figure 3 is a polychromatic focal point displacement curve diagram of an optical system of a high-magnification achromatic telecentric lens provided by the embodiment one of the utility model, Figure 4 is a distortion diagram of the optical system of the high-magnification achromatic telecentric lens provided by the embodiment one of the utility model;

[0090] As shown in Figure 3 , the optical system realizes complex achromatism for 436nm, 525nm and 656nm wavelengths, thereby effectively correcting chromatic aberration;As shown in Figure 4 , the optical system has a full field of view distortion less than 0.05%.

[0091] In summary, the optical system in the test example can achieve a magnification of 4, a numerical aperture NA of 0.164, and a resolution of 2.2 microns in the micro level;The maximum imaging surface reaches Φ44mm, which can be matched with a 6500W pixel, a 38mm diagonal camera, an 8k5μm line scanning camera, and can meet the needs of high-precision detection fields such as semiconductors, mini-LEDs, FPD displays, and general semiconductors;The complex achromatic design is adopted, and the achromatic wavelength is compatible to 436nm, which improves the chromatic aberration problem of the high-magnification telecentric lens.

[0092] Embodiment two

[0093] Please refer to Figure 5 , Figure 5 is a structure schematic view of an optical system of a high-magnification achromatic telecentric lens provided by the embodiment two of the utility model;

[0094] As shown in Figure 5 , the optical system comprises:

[0095] comprises a first lens G1 with positive refractive power, a second lens G2 with negative refractive power, a third lens G3 with positive refractive power, a fourth lens G4 with negative refractive power, a fifth lens G5 with positive refractive power, a sixth lens G6 with negative refractive power, a seventh lens G7 with positive refractive power, a stop T, an eighth lens G8 with negative refractive power, a ninth lens G9 with negative refractive power, a tenth lens G10 with positive refractive power and an eleventh lens G11 with positive refractive power, which are sequentially arranged from the object side to the image side;Wherein, the first lens G1 to the seventh lens G7 form a front lens group 100, the eighth lens G8 to the tenth lens G10 form a rear lens group 200, and the stop T is placed at the focal point of the front lens group 100 to form a telecentric architecture;

[0096] The working distance of the optical system is WD, and the numerical aperture of the optical system is NA, and WD and NA satisfy the relationship: NAxWD<13.

[0097] Further, the focal length of the front lens group 100 is f100 The focal length of the rear lens group 200 is f. 200 f 100 with f 200 The relation is satisfied: 0.4 < |f 200 / f 100 |<1;

[0098] Specifically, the second lens G2, the third lens G3 and the fourth lens G4 form a cemented triplet lens U1, and the fifth lens G5 and the sixth lens G6 form a cemented doublet lens U2.

[0099] The focal length of the first lens G1 is f1, and the focal length of the cemented triplet lens U1 is f. U1 The focal length of the cemented doublet lens U2 is f. U2 The focal length of the seventh lens G7 is f7.

[0100] f1 and f 100 The relation is satisfied: 0.35 < |f 100 / f1|<0.95;

[0101] f U1 with f 100 Satisfy the relation: |f 100 / f U1 |<0.2;

[0102] f U2 with f 100 Satisfy the relation: |f 100 / f U2 |<0.26;

[0103] f7 and f 100 The relation is satisfied: 0.3 < |f 100 / f7|<0.9.

[0104] Specifically, the refractive index of the third lens G3 is n3, and its Abbe number is v3, which satisfies the relationship: 1.42 <n3<1.65;60<v3<95;

[0105] The fifth lens G5 has a refractive index of n5 and an Abbe number of v5, satisfying the relation: 1.42 <n5<1.65;60<v5<95。

[0106] Specifically, the ninth lens G9 and the tenth lens G10 form a cemented doublet lens U3;

[0107] The focal length of the eighth lens G8 is f8, and the focal length of the cemented doublet U3 is f. U3 The focal length of the eleventh lens G11 is f. 11 ;

[0108] f8 and f 200satisfies the relationship: 0.45<|f8 / f 200 <0.9;

[0109] f U3 satisfies the relationship: 0.45<|f8 / f 200 satisfies the relationship: 0.45<|f8 / f 200 satisfies the relationship: 0.45<|f8 / f U3 <0.5;

[0110] f 11 satisfies the relationship: 0.45<|f8 / f 200 satisfies the relationship: 0.45<|f8 / f 11 satisfies the relationship: 0.45<|f8 / f 200 <5.

[0111] In this embodiment, the reasonable distribution of the positive and negative lens intervals and the focal power of the front lens group 100 can form smaller spherical aberration and field curvature, reduce the tolerance sensitivity, and maintain a suitable lens profile, which is easy to process; the combination of the three cemented lenses U1 in the negative, positive, and negative forms and the double cemented lens U2 can well correct the chromatic aberration of the system, the third lens G3 and the fifth lens G5 are selected from materials with low dispersion to further enhance the chromatic aberration correction effect, so that the achromatic waveband of the system is compatible to 436nm wavelength, and the cemented surface thereof can correct high-order aberration; the double cemented lens U3 in the rear lens group 200 is a new type of cemented lens, which can balance the field curvature of the lens optical system, and the cemented surface thereof can correct astigmatism and distortion; the lens group 100 has positive focal power, and the eighth lens with negative focal power is separated by a certain distance, which is also beneficial to correct spherical aberration and field curvature.

[0112] In this embodiment, the first lens G1 to the eleventh lens G11 are all glass spherical lenses.

[0113] Among them, the first lens G1, the third lens G3, the fifth lens G5, the seventh lens G7, the tenth lens G10 and the eleventh lens G11 are all double convex lenses, the second lens G2, the fourth lens G4 and the sixth lens G6 are all meniscus lenses, and the eighth lens G8 is a double concave lens.

[0114] In this embodiment, the optical axes of all the glass spherical lenses are on the predetermined optical axis;

[0115] The aperture of the diaphragm T is a circular hole, and the center of the circular hole is on the predetermined optical axis.

[0116] It can be understood that the aperture value of the diaphragm T needs to be adjusted according to the specific application scene.

[0117] In order to verify whether the above optical system meets the design purpose, the following is a specific test example given according to the above settings of this embodiment:

[0118] In this test example, the lens data of the optical system is shown in the following Table Three:

[0119] Table III

[0120]

[0121]

[0122] It should be noted that in Table III, the "front surface" corresponds to the left side surface of the lens or lens group, and the "back surface" corresponds to the right side surface of the lens or lens group; or it can be understood that the object side is on the left side, and the image side (or image surface) is on the right side, the side surface close to the object side is the "front surface", and the side surface close to the image side is the "back surface". Figure 5 Figure 5 Figure 5 Figure 5

[0123] In the present test example, the combined focal length f 100＝ of the front lens group 100 is 56mm; the focal length f1 of the first lens G1 is 89mm; the focal length f U1 of the three-cemented lens group U1 is -537mm; the focal length f U2 of the double-cemented lens U2 is 295mm; the focal length f7 of the seventh lens G7 is 100mm; the combined focal length f 200 of the rear lens group 200 is -46mm; the focal length f8 of the eighth lens G8 is -30mm; the focal length f U3 of the double-cemented lens U3 is 214mm; the focal length f 11 of the eleventh lens G11 is 182mm.

[0124] Substituting the above values into the respective relationships, the following is obtained:

[0125] |f 200 / f 100 |=0.821, |f 100 / f1|=0.629, |f 100 / f U1 |=0.104, |f 100 / f U2 |=0.189, |f 100 / f7|=0.556, |f8 / f 200 |=0.652, |f 200 / f U3 |=0.215, |f 11 / f 200 |=3.96.

[0126] Therefore, the relevant relationships of the present embodiment are satisfied, i.e.:

[0127] 0.4<|f​​​​200 / f 100 |<1,0.35<|f 100 / f1|<0.95,|f 100 / f U1 |<0.2,|f 100 / f U2 |<0.26,0.3<|f 100 / f7|<0.9,0.45<|f8 / f 200 |<0.9,|f 200 / f U3 |<0.5,2.5<|f 11 / f 200 |<5。

[0128] In the present test example, the optical parameters of the optical system are shown in Table Four as follows:

[0129] Table Four

[0130]

[0131]

[0132] Wherein, the calculation formula of the resolution is 0.65*lambda / NA, and lambda is the wavelength (0.55 microns in the embodiment).

[0133] Please refer to Figure 6 , Figure 7 and Figure 8 , Figure 6 is an image side MTF (Modulation Transfer Function) curve of the optical system of the high-magnification achromatic telecentric lens provided in the embodiment one of the utility model, Figure 7 is a polychromatic light focal point displacement curve of the optical system of the high-magnification achromatic telecentric lens provided in the embodiment one of the utility model, Figure 8 is a distortion diagram of the optical system of the high-magnification achromatic telecentric lens provided in the embodiment one of the utility model;

[0134] As shown in Figure 7 , the optical system realizes complex achromatism for wavelengths near 436nm, 525nm and 656nm, thereby effectively correcting chromatic aberration and improving imaging quality;As shown in Figure 8 , the optical system has a full field of view distortion less than 0.04%.

[0135] In summary, the optical system in this test example achieves a magnification of up to 5x and a numerical aperture (NA) of 0.176, enabling a resolution at the 2-micron level. Its maximum imaging surface reaches Φ44mm, allowing it to be used with a 6500W pixel, 38mm diagonal camera and an 8k 5μm line scan camera, meeting the high-precision detection needs of fields such as semiconductors, mini LEDs, FPD displays, and general semiconductors. Furthermore, its apochromatic design ensures compatibility with wavelengths up to 436nm, improving upon the chromatic aberration issues present in high-magnification telecentric lenses.

[0136] Example 3:

[0137] This embodiment provides a high-magnification achromatic telecentric lens, including the optical system of a high-magnification achromatic telecentric lens as described in Embodiment 1 or Embodiment 2.

[0138] Since the optical system has been described in detail in the above embodiments, it will not be repeated in this embodiment.

[0139] In summary, this embodiment of the invention achieves a magnification of over 4x, a numerical aperture (NA) of less than 0.18, and a resolution at the 2-micron level. The maximum imaging surface reaches Φ44mm, allowing it to be used with a 6500W pixel camera, a 38mm diagonal camera, and an 8k 5μm line scan camera, meeting the needs of high-precision detection fields such as semiconductors, mini LEDs, FPD displays, and general semiconductors. The apochromatic design, with apochromatic wavelength compatibility up to 436nm, improves the chromatic aberration problem present in high-magnification telecentric lenses.

[0140] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. An optical system for a high-magnification achromatic telecentric lens, characterized in that, The system includes, in order from object to image, a first lens G1 with positive optical power, a second lens G2 with negative optical power, a third lens G3 with positive optical power, a fourth lens G4 with negative optical power, a fifth lens G5 with positive optical power, a sixth lens G6 with negative optical power, a seventh lens G7 with positive optical power, an aperture stop T, an eighth lens G8 with negative optical power, a ninth lens G9 with negative optical power, a tenth lens G10 with positive optical power, and an eleventh lens G11 with positive optical power; wherein, the first lens G1 to the seventh lens G7 form a front lens group (100), the eighth lens G8 to the tenth lens G10 form a rear lens group (200), and the aperture stop T is placed at the focal point of the front lens group (100) to form a telecentric structure. The working distance of the optical system is WD, and the numerical aperture of the optical system is NA. WD and NA satisfy the relationship: NA×WD<13.

2. The optical system of a high-magnification achromatic telecentric lens according to claim 1, characterized in that, The focal length of the front lens group (100) is f 100 The focal length of the rear lens group (200) is f. 200 f 100 with f 200 The relation is satisfied: 0.4 < |f 200 / f 100 |<1.

3. The optical system of a high-magnification achromatic telecentric lens according to claim 2, characterized in that, The second lens G2, the third lens G3 and the fourth lens G4 form a cemented triplet lens U1, and the fifth lens G5 and the sixth lens G6 form a cemented doublet lens U2. The focal length of the first lens G1 is f1, and the focal length of the cemented triplet lens U1 is f. U1 The focal length of the cemented doublet lens U2 is f. U2 The focal length of the seventh lens G7 is f7. f1 and f 100 The relation is satisfied: 0.35 < |f 100 / f1|<0.95; f U1 with f 100 Satisfy the relation: |f 100 / f U1 |<0.2; f U2 with f 100 Satisfy the relation: |f 100 / f U2 |<0.26; f7 and f 100 The relation is satisfied: 0.3 < |f 100 / f7|<0.

9.

4. The optical system of a high-magnification achromatic telecentric lens according to claim 3, characterized in that, The third lens G3 has a refractive index of n3 and an Abbe number of v3, satisfying the relation: 1.42 <n3<1.65;60<v3<95; The fifth lens G5 has a refractive index of n5 and an Abbe number of v5, satisfying the relation: 1.42 <n5<1.65;60<v5<95。 5. The optical system of a high-magnification achromatic telecentric lens according to claim 4, characterized in that, The ninth lens G9 and the tenth lens G10 form a cemented doublet lens U3; The focal length of the eighth lens G8 is f8, and the focal length of the cemented doublet U3 is f. U3 The focal length of the eleventh lens G11 is f. 11 ; f8 and f 200 The relation is satisfied: 0.45 < |f8 / f 200 |<0.9; f U3 with f 200 Satisfy the relation: |f 200 / f U3 |<0.5; f 11 with f 200 Satisfies the relation: 2.5 < |f 11 / f 200 |<5.

6. The optical system of a high-magnification achromatic telecentric lens according to claim 1, characterized in that, Lenses G1 through G11 are all glass spherical lenses.

7. The optical system of a high-magnification achromatic telecentric lens according to claim 6, characterized in that, The first lens G1, the third lens G3, the fifth lens G5, the seventh lens G7, the tenth lens G10, and the eleventh lens G11 are all biconvex lenses; the second lens G2, the fourth lens G4, and the sixth lens G6 are all meniscus lenses; and the eighth lens G8 is a biconcave lens.

8. The optical system of a high-magnification achromatic telecentric lens according to claim 7, characterized in that, The optical axes of all glass spherical lenses are on the predetermined optical axis; The aperture of the aperture T is a circular hole, and the center of the circular hole is on the predetermined optical axis.

9. A high-magnification achromatic telecentric lens, characterized in that, The optical system includes a high-magnification achromatic telecentric lens as described in any one of claims 1-8.

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