JP2020512596A - Lens system for macro lenses for industrial use introduced for quality assurance in the production process - Google Patents

Abstract

INDUSTRIAL APPLICABILITY The present invention is a macro lens for industrial use, which is introduced for quality assurance in a production process, and has an object side lens group, an image side lens group, and one aperture stop located between them. At that time, the object-side lens group includes, from the object side to the image side, a first partial lens group having a positive refractive power, a second partial lens group having a negative refractive power, and a positive partial power. A third partial lens group having a refractive power, wherein the image side lens group has a negative refractive power and a first partial lens group having a positive refractive power from the object side toward the image side. The present invention relates to a macro lens having a second partial lens group having a power and a third partial lens group having a positive refractive power.

Description

  The present invention provides, for example, a lens system for a macro lens (Makroobjektiv) for industrial use that is introduced for quality assurance in a production process at a display manufacturing site, a macro lens equipped with such a lens system, and such a macro lens. The present invention relates to an optical inspection system for an object used.

  Various industrial macro lenses are introduced for quality assurance. In that case, the inspection system that has been constructed is used to scan an object to be inspected (objekt) such as a display having a surface with a certain spread in a scanning process. . In order to capture data over the full width of the object, a number of inspection units, in particular cameras with objectives, are arranged side by side in an inspection row. The various information thus obtained may be transmitted to the central evaluation unit, for example by being transmitted to an existing network via a standardized interface such as GigE Vision.

  At that time, an attempt is made to minimize the number of inspection units per inspection row while maintaining the same object resolution. By reducing the number of inspection units per inspection row, adjustment man-hours, procurement costs and associated infrastructure will be kept low for the same inspection quality.

  One of the possibilities of reducing the number of inspection units is to introduce an objective lens having a large image circle diameter, which is very excellent in imaging performance. In this case, the investment cost for such an objective lens must not be canceled out due to the reduction in the number of inspection units and the cost savings that have been tied together.

  The currently available industrial macrolenses for the above mentioned purposes have an image circle diameter of 60 mm with the required imaging performance. Nevertheless, the introduction of such an objective lens into the illumination of a sensor with an image circle diameter of at most 80 mm already causes a pronounced field aberration. As a result, the inspection quality of the peripheral portion of the image plane is undesirably deteriorated.

  Depending on the configuration of a known macro lens, it is impossible to achieve sufficient correction of image plane-dependent first-order aberrations such as field curvature and astigmatism. As a result, the image quality at the edge of the image plane is already visibly degraded, but the image circle diameter is limited to a maximum of 2y '= 80 mm.

  The object of the invention is to present a lens system for a macrolens which is introduced for the above-mentioned purpose, which results in a larger image circle diameter than currently known objective lenses.

  Besides that, even if the existing inspection station has a fixed length of the optical transmission line, that is, the distance between the object and the image, and the imaging scale is also fixed, it is better. It is also an issue to present a lens system for a macro lens that will provide imaging performance.

  This problem is solved by a lens system for a macro lens having the features of claim 1 which is an independent claim, by a macro lens having such a lens system, and by an object using such a macro lens. Solved by optical inspection system. Each dependent claim presents further features of the invention.

  The lens system according to the present invention includes an object side lens group, an image side lens group, and one aperture stop located between the object side lens group and the image side lens group. The object-side lens group includes, from the image side to the object side, a first partial lens group having a positive refractive power, a second partial lens group having a negative refractive power, and a second partial lens group having a positive refractive power. And three partial lens groups. The image-side lens group includes, from the object side to the image side, a first partial lens group having a positive refractive power, a second partial lens group having a negative refractive power, and a second partial lens group having a positive refractive power. And three partial lens groups. That is, both lens groups are composed of partial lens groups symmetrically arranged with the aperture stop interposed therebetween and having a positive-negative-positive refractive power distribution system.

In the preferred embodiment of the lens system, each of the following features:
A first partial lens group of the object-side lens group consisting of one or two single lenses; a second partial lens group of the object-side lens group consisting essentially of one to three single lenses or one cemented lens. Partial lens group-Third partial lens group of object-side lens group, which consists essentially of one single lens and / or one cemented lens-Image-side lens group, consisting essentially of one or two single lenses A second partial lens group of the image-side lens group consisting of substantially one to three single lenses or one cemented lens, and / or substantially one single lens and / or The third sub-lens group of the image-side lens group, which consists of one cemented lens, may be contemplated alone or in any combination.

  The expression “consisting essentially of” may have, in addition to each lens referred to above as a component, a focal length greater than or equal to the total focal length of the lens system. In addition, for that reason, a plurality of lenses that actually have no refractive power, other various optical components such as diaphragms, masks, cover glasses, etc., various mechanical components such as lens flanges, lens barrels, imaging elements, It means that the camera shake correction mechanism may be included in the optical lens system.

  It is preferable that the imaging scale of the lens system is located within a section from β ′ = − 0.7 to β ′ = − 5.0.

  In one example of an expanded configuration, at least one of the partial lens groups, preferably one optical element in all the partial lens groups, has a very wide spectral correction, in particular a reduction of the secondary spectrum. It is contemplated to have an anomalous partial variance of | ΔPg, F | ≧ 0.01 such that

）補正の残留収差Ｘに関して、次式が成立することが企図され得る。

レンズ系の像側開口数は、ＮＡ’≧０．０４であることが好ましい。 In that case, in particular, the axial chromatic aberration of the lens system in the closed section [-0.7; -5.0] of the imaging scale (

) For the residual aberration X of the correction, it can be envisaged that

The image-side numerical aperture of the lens system is preferably NA ′ ≧ 0.04.

）
にしたがった多色波面収差の標準偏差として測定される結像性能が、回折だけにより制限されている。 In an example of a specific configuration of the lens system, the Marechal evaluation criterion-wavefront_RMS ≦ λ / 14′-
(

)
The imaging performance, measured as the standard deviation of the polychromatic wavefront aberration according to, is limited only by diffraction.

  With the lens system according to the present invention, it is possible to prevent artificial vignetting from the center to the periphery of the sensor, but it is indispensable even if it is limited by diffraction. Together with the aperture, a desired resolution up to the peripheral portion of the sensor is guaranteed.

In an example of an advantageous embodiment, the ratio between the total focal length f ′ and the sensor diagonal 2y ′ (max) satisfies the condition:

  In a likewise advantageous embodiment, the first partial lens group of the object-side lens group comprises one object-side meniscus lens. The center of curvature of the meniscus lens is preferably located on the object side of the meniscus lens.

  In another equally advantageous embodiment of the lens system, it is contemplated that the first sub-lens group of the image-side lens group comprises one image-side meniscus lens. The center of curvature of the image-side meniscus lens is advantageously located on the image side of the meniscus lens.

式中、ｆ’（Ｍ）はメニスカスレンズの焦点距離、ｆ’（全）はマクロレンズの焦点距離である。 For the meniscus lens on the object side and the meniscus lens on the image side, the following equation holds.

In the formula, f ′ (M) is the focal length of the meniscus lens, and f ′ (total) is the focal length of the macro lens.

In an example of the embodiment, the absolute value of the focal length of the meniscus on both outer sides is expressed by the following equation:
| F '(outermost meniscus) | ≤300 mm
May be contemplated to hold.

  In the development configuration example of the present invention, the center of curvature of the lens surface directly adjacent to the aperture stop of the third partial lens group of the object side lens group is located on the object side, and / or the image side lens. It is contemplated that the center of curvature of the lens surface that is directly adjacent to the aperture stop of the third partial lens group of the group is located on the image side, and that the following conditions are satisfied for the radius of curvature R of each lens surface. To be done.

  Hereinafter, some embodiments of the present invention will be described in detail with reference to the drawings.

It is a lens sectional view of a 1st embodiment which has the 1st imaging scale. It is a lens sectional view of a 2nd embodiment which has the 2nd imaging scale. It is a lens sectional view of a 3rd embodiment which has the 3rd imaging scale. FIG. 4 shows an inspection system with a macro lens according to any one of FIGS.

  FIG. 1 shows a first embodiment of a macro lens 1001 having an optical lens system 1 in a lens cross-sectional view in which a scale is faithfully reproduced. The lens system 1 described as an embodiment here has an imaging scale β ′ of −2 and is configured as a two-division type lens system, and each of the partial lens groups is formed along the central optical axis A. It has a first lens group G1 and a second lens group G2 each having three lenses.

  The partial lens groups of the first lens group G1 have the reference signs G11, G12, G13, and the partial lens groups of the second lens group G2 have the reference signs G23, G22, G21. Each of the partial lens groups G1 and G2 has a positive-negative-positive refractive power in order. Specifically, the first partial lens group G11 located outside the first lens group G1 has a positive refractive power, and the central second partial lens group G12 of the first lens group G1 has a negative refractive power. Means that the third partial lens group G13 located inside the first lens group G1 has a positive refractive power.

  The distribution method of the refractive power of the second lens group G2 is also the same, that is, the first partial lens group G21 located outside the second lens group G2 has a positive refractive power and the second lens group G2 has a positive refractive power. The second partial lens group G22 at the center of G2 has a negative refractive power, and the third partial lens group G23 located inside has a positive refractive power.

  One aperture stop APE is provided between both lens groups G1 and G2. The apertures or apertures shown in the respective figures are not necessarily drawn to scale and faithfully reproduce the size and shape, and they show the positions of the apertures / apertures along the optical axis A. .

  Now, hereinafter, the configuration of the lens system will be described from left to right, that is, from the object side to the image side. The distances between the object and the first lens on the object side, and between the last lens on the image side and the image are shorter than they really are, for drawing reasons. Here, the center and peripheral radiations that have been entered are also drawn in a correspondingly shortened manner.

The first lens group G11 on the object side has a positive refracting power as a whole, and has one meniscus lens 10 on the object side. The meniscus lens 10 is made of flint glass having an Abbe number ν _d of 24.42 and a refractive index n _d of 1.805181. All of the numerical values given for the Abbe number and the refractive index are valid values for the Fraunhofer line when the wavelength is 587.5618 nm. The meniscus lens 10 has a concave surface 101 on the object side and a convex surface 102 on the image side. The concave surface 101, like all surfaces in this example, is spherical and has a radius of curvature which may be, for example, -57.8965 mm.

  Basically, however, it can be said that an optical system as described here is capable of proportional scaling, for example to accommodate different image sizes, and is therefore described here. The radii, diameters, thicknesses and distances given are to be construed as exemplary only.

  The radius of curvature of the image-side convex surface 102 is smaller than the radius of the object-side surface 101, which is -53.4548 mm. The centers of curvature of both surfaces 101, 102 of the meniscus lens 10 on the first object side are located on the object side. The distance between the vertices of both surfaces 101, 102 of the meniscus lens 10 from each other is 7.00 mm.

  As a second lens as a whole and as a second lens of this partial lens group G11, a lens 11 formed in an uneven shape is provided. The second lens 11 is made of crown glass having an Abbe number of 67.74 and a refractive index of 1.595220.

  The second lens 11 has a first convexly curved surface 111 on the object side, and its radius of curvature is 52.9806 mm. The apex of the convex surface 111 is separated from the apex of the image-side second surface 102 of the meniscus lens 10 by 2.00 mm.

  The image-side second concavely curved surface 112 has a radius of curvature of 407.9243 mm and its apex is 7.00 mm away from the apex of the object-side surface 111.

  The first lens 10 and the second lens 11 together form a first partial lens group G11 having a positive refracting power as a whole.

  The second partial lens group G12 has a negative refractive power, and is substantially composed of one single lens, that is, the third lens 12. The third lens 12 is made of flint glass and has an Abbe number of 42.41 and a refractive index of 1.637750. The object-side concavely curved surface 121 has a radius of curvature of -51.8151 mm, and the image-side similarly concavely curved surface 122 has a radius of curvature of 42.852 mm. The apex of the image-side surface 122 is 4.00 mm away from the apex of the object-side surface 121.

  The third partial lens group G13 has a positive refracting power, and substantially cements the fourth lens 13 on the object side and the fifth lens 14 on the image side, which are different in glass type, from each other. It consists of one cemented lens made. The optical characteristics at the junction between the two lenses 13 and 14 are considered to be negligible for their effect on the entire lens system, and therefore will not be described in detail.

  The fourth lens 13 has a surface 131 that is convexly curved toward the object side, and has a radius of curvature of 135.8602 mm. The apex of the surface 131 is separated from the apex of the image-side surface 122 of the third lens 12 by 8.00 mm.

  The image-side surface of the fourth lens 13 is identical in geometry to the object-side surface 141 of the fifth lens 14. This surface is formed convex with respect to the fifth lens 14 and has a radius of curvature of 59.0741 mm, and its apex is the apex of the object-side first surface 131 of the fourth lens 13. From 9.00 mm.

  The fifth lens 14 is likewise made from crown glass and has an Abbe number of 67.74 and a refractive index of 1.595220. The image-side second surface 142 of the fifth lens 14 is similarly formed in a convex shape and has a radius of curvature of −63.4152 mm, and its apex is on the object side of the fifth lens 14. Is 8.00 mm from the apex of the first surface 141 of.

  This fifth lens 14 is followed by one aperture stop at a distance of 1.00 mm.

  Further, at a distance of 1.00 mm, the apex of the object-side first surface 151 of the sixth lens 15 forming the cemented lens together with the seventh lens 16 is located. This cemented lens also forms the third partial lens group G23 of the image side lens group G2.

  The radius of curvature of the object-side convex surface 151 is 82.5025 mm, and the apex thereof is 6.00 mm away from the apex of the object-side first concave surface 161 of the seventh lens 16. The sixth lens 15 is made of the same crown glass as the fifth lens 14 and has an Abbe number of 67.74 and a refractive index of 1.595220.

  The seventh lens 16 is likewise made of crown glass, has an Abbe number of 56.81 and a refractive index of 1.607379. The radius of the above-described object-side first surface 161 is −67.1127 mm. The apex of the surface 161 on the object side is separated by 5.00 mm from the apex of the second convex surface 162 on the image side.

  The second convex object-side surface 162 has a radius of curvature of −54.9014 mm.

  The cemented lens forming this third partial lens group G23 having positive refractive power is separated by a distance of 10.00 mm with respect to the apex of each surface, and the second partial lens having negative refractive power. The eighth lens 17 forming the group G22 follows.

  The eighth lens 17 has a concavely curved surface 171 with a radius of curvature of −55.0234 mm on the object side, and has a concavely curved surface with a radius of curvature of 68.6862 mm on the image side. A surface 172 is provided. These surfaces 171, 172 are 4.00 mm apart from each other at their vertices. The eighth lens 17 is made of flint glass having an Abbe number of 42.41 and a refractive index of 1.637750.

  Following this, the first partial lens group G21 of the second lens group G2 consists essentially of two meniscus lenses 18, 19.

  The object-side first lens 18 of the first partial lens group G21 is also made of the crown glass of the fifth lens 14 and the sixth lens 15, and its Abbe number is 67.74. The refractive index is 1.595220. The object-side surface 181 of the ninth lens 18 is formed in a concave shape, and its apex is 15.00 mm away from the apex of the image-side second surface 172 of the eighth lens 17, and −89. It has a radius of curvature of 8561 mm. The second image-side surface 182 is convexly formed, has a radius of curvature of -52.0433 mm, and is 7.00 mm away from the apex of the object-side first surface 181.

  The tenth lens 19 forms the first partial lens group G21 together with the ninth lens 18. The tenth lens 19 is made of flint glass having an Abbe number of 18.90 and a refractive index of 1.922860. The first convex surface 191 on the object side has a radius of curvature of 85.7767. Its apex is 2.00 mm away from the apex of the second image-side surface 182 of the ninth lens 18. The second image-side concave surface 192 of the tenth lens 19 has a radius of curvature of 88.7231 mm, and its apex is 6.00 mm from the apex of the first object-side surface 191. is seperated.

  The object OBJ is 126.58 mm away from the apex of the first surface 101 of the initial lens 10. The image BIL is 303.40 mm away from the apex of the second surface 192 of the tenth lens 19.

The codes, radii, thicknesses and material specifications of each surface are summarized in the following table in the form of a list.

  FIG. 2 shows a second embodiment 1002 of the macro lens of the optical lens system 2 in a lens cross-sectional view in which the scale is faithfully reproduced. The lens system 2 shown in FIG. 2 has an imaging scale β ′ of −5. This lens system has in principle the same construction as the lens system 1 described as the first example, ie each has three partial lens groups G11, G12, G13 and G23, G22, G21. It has two lens groups G1 and G2. In each lens group, each partial lens group has positive-negative-positive refractive power in order.

  Here again, a lens system with ten lenses is produced. The arrangement from the object to the image of each lens and the partial lens group to which each lens belongs are as follows.

  The first meniscus lens 20 of the first lens group G1 having the concave surface 201 on the object side and the convex surface 202 on the image side is the same as the second lens 21 having the convex surface 211 on the object side and the convex surface 222 on the image side. In addition, the first partial lens group G11 having a positive refractive power is formed.

  The second partial lens group G12 is a cemented lens including a third lens 22 having a convex surface 221 on the object side and a fourth lens 23 having a concave surface 231 on the object side and a concave surface 232 on the image side. Formed by. The second partial lens group G12 has a negative refractive power.

  The third partial lens group G13 of the first lens group G1 is formed by only one meniscus lens, specifically, a fifth lens 24 having a convex surface 241 on the object side and a concave surface 242 on the image side. .

  The third partial lens group G13 of the first lens group G1 is followed by the third partial lens group G23 having the positive refractive power of the second lens group G2. An aperture diaphragm APE is arranged between both partial lens groups.

  This third partial lens group G23 of the second lens group G2 consists essentially of only one meniscus lens, in particular a sixth lens 25 having a concave surface 251 on the object side and a convex surface 252 on the image side. Made of

  The second partial lens group G22 of the second lens group G2 also has a negative refractive power, and includes one cemented lens. This cemented lens consists essentially of a seventh lens 26 having an object-side concave surface 261 shaped substantially to the geometry of the image-side surface 252 of the adjacent sixth lens 25. ing. On the image side, the object-side convex surface 271 of the eighth lens 27 continues across the cemented point, and together with this, the seventh lens 26 forms one cemented lens. The eighth lens 27 has a convex surface 272 on the image side.

  The first partial lens group G21 of the second lens group G2 has a positive refractive power, and substantially has a ninth biconvex lens 28 having an object-side surface 281 and an image-side surface 282. , And a meniscus lens 29 having an object-side convex surface 291 and a concave image-side surface 292.

The radius of curvature, thickness and glass parameters for each lens are apparent from the following table.

  FIG. 3 shows a third embodiment 1003 of the macro lens of the optical lens system 3 in a lens sectional view in which the scale is faithfully reproduced. The lens system 3 shown in FIG. 3 has an imaging scale β ′ of −0.7. This lens system also has in principle the same construction as the two embodiments described above. This lens system can be divided into two partial lens groups G1, G2, each having three partial lens groups G11, G12, G13 and G23, G22, G21. In each of the partial lens groups, the refracting powers are arranged in the order of positive-negative-positive.

  The lens system 3 has thirteen lenses, four of which are cemented to two cemented lenses. The arrangement from the object to the image of each lens and the partial lens group to which each lens belongs are as follows.

  The first partial lens group G11 of the first lens group G1 has a positive refractive power, and substantially has a first object-side convex surface 301 and an image-side concave surface 302. It comprises a meniscus lens 30 and a second meniscus lens 31 on the image side having a convex surface 311 on the object side and a concave surface 312 on the image side.

  The second partial lens group G12 of the first lens group G1 has a negative refracting power as a whole, and is substantially composed of two single lenses. The third meniscus lens 32 has a concave surface 321 on the object side and a convex surface 322 on the image side. The fourth lens 33 is biconcave, and has a concave surface 331 on the object side and a concave surface 332 on the image side.

  The third partial lens group G13 of the first lens group G1 has a positive refracting power as a whole, and is substantially composed of one cemented lens and one biconvex single lens. The cemented lens cements the fifth lens 34 having the convex surface 341 on the object side, the convex surface 351 to which the fifth lens 34 is attached to the object side, and the sixth lens 35 having the concave surface 352 on the image side. Is made. Yet another single lens attached to the third lens group G13 is a seventh biconcave lens 36 having an object-side surface 361 and an image-side surface 362.

  The third partial lens group G23 of the second lens group G2 is formed of one cemented lens having a positive refractive power, which is made by cementing the eighth lens 37 and the ninth lens 38. The eighth lens 37 has a biconvex shape having an object-side surface 371, and the ninth lens 38 has a concave object-side surface 381 to which the eighth lens 37 is attached on the object side. It has a meniscus shape having a convex image-side surface 382.

  The second partial lens group G22 of the second lens group G2 is formed of a tenth lens 39 and an eleventh lens 40 which have a negative refractive power when the two are combined. The tenth lens 39 is biconcave having an object side surface 391 and an image side surface 392, and the eleventh lens 40 is a convex object side surface 401 and an object side concave surface 402. It is configured as a meniscus lens having

  The first lens group G21 of the second lens group G2 is substantially composed of two meniscus lenses 41 and 42. The twelfth lens 41 having the concave surface 411 on the object side and the convex surface 412 on the image side forms the first meniscus lens on the object side among these meniscus lenses. The second image-side meniscus lens is a thirteenth lens 42 which similarly has a concave surface 421 on the object side and a convex surface 422 on the image side.

The radius of curvature, thickness and glass parameters for each lens are apparent from the following table.

  An inspection system 2000 is shown in FIG. The inspection system 2000 is designed for optical inspection of the surface of the object 2001. The surfaces to be scrutinized preferably extend in the same plane. The surface that is the subject of scrutiny can be, for example, a display.

  The inspection system 2000 has one inspection camera array 2005 having a fixed number of inspection cameras 2006 each including one macro lens 1001 having a lens system. Depending on the application, other macro lenses 1002, 1003 according to the invention or another macro lens with a suitable focal length may be introduced. In the embodiment shown in FIG. 4, this fixed number of inspection cameras 2006 are arranged in a row 2008.

  The inspection system 2000, in this embodiment, has one transport device 2004, which in this embodiment targets the object 2001 under scrutiny relative to the row 2008, in particular. Conveyance is performed vertically with respect to the row 2008 and horizontally along the conveyance direction 2002. The transport device 2004 can be, for example, any conveyor belt or scanning table. Of course, the transport device 2004 may be designed for transport motions in directions other than horizontal. Furthermore, as an option, instead of the object 2001, the inspection camera array 2005 may perform relative motion with respect to the object 2001 that is the object of close inspection.

Claims (13)

A lens system (1) for a macro lens for industrial use, which is introduced for quality assurance in the production process,
a) It has an object side lens group (G1), an image side lens group (G2), and one aperture stop (APE) located between them, and at that time,
b) The object side lens group (G1) has a first partial lens group (G11) having a positive refractive power and a second partial lens group having a negative refractive power from the object side to the image side. (G12) and a third partial lens group (G13) having a positive refractive power,
c) The image side lens group (G2) has a first partial lens group (G23) having a positive refractive power and a second partial lens group having a negative refractive power from the object side to the image side. (G22) and a third partial lens group (G21) having a positive refractive power,
Lens system (1). The lens system according to claim 1, wherein
a) The first partial lens group (G11) of the object side lens group is composed of one or two single lenses (10, 11),
b) The second partial lens group (G12) of the object side lens group is composed of one to three single lenses (12) or one cemented lens,
c) The third partial lens group (G13) of the object side lens group is composed of one single lens and / or one cemented lens (13, 14),
d) The first partial lens group (G21) of the image side lens group is composed of one or two single lenses (18, 19),
e) The second partial lens group (G22) of the image side lens group is composed of one to three single lenses (17) or one cemented lens, and / or
f) The third partial lens group (G23) of the image side lens group is composed of one single lens and / or one cemented lens (15, 16),
Lens system.   The lens system according to claim 1 or 2, wherein the imaging scale of the lens system (1) is located within a section from β '=-0.7 to β' =-5.0. , Lens system.   The lens system according to any one of claims 1 to 3, wherein in at least one of the partial lens groups, one optical element has an abnormal partial dispersion of | ΔPg, F | ≧ 0.01. Having a lens system. The residual aberration X of the axial chromatic aberration correction of the lens system according to any one of claims 1 to 4, wherein the axial chromatic aberration correction is within the closed section [-0.7; -5.0] of the imaging scale. , A lens system in which the following equation holds.

The lens system according to any one of claims 1 to 5, wherein the following expression is established for an image-side numerical aperture NA '.
NA '≧ 0.04   The lens system according to any one of claims 1 to 6, wherein the imaging performance measured as the standard deviation of the polychromatic wavefront aberration according to the Marechal evaluation criterion-wavefront_RMS ≤ λ / 14'- A lens system that is limited only by diffraction. The lens system according to any one of claims 1 to 7, wherein the following relationship holds between the total focal length f'of the lens system and the sensor diagonal 2y '(maximum).

The lens system according to any one of claims 1 to 8, wherein:
a) The first partial lens group (G11) of the object side lens group (G1) has one object side meniscus lens (10), in which case the object side meniscus lens ( The center of curvature of 10) is located on the object side of this meniscus lens (10), and / or
b) The first partial lens group (G21) of the image side lens group (G2) has one image side meniscus lens (19), in which case the image side meniscus lens (G21) The lens system in which the center of curvature of 19) is located on the image side of the meniscus lens (19), and the following conditions are satisfied.
c)

(Where f '(M) is the focal length of the meniscus lens, and f' (total) is the focal length of the macro lens) The lens system according to any one of claims 1 to 9, wherein:
a) the center of curvature of the lens surface of the third partial lens group (G13) of the object side lens group directly adjacent to the aperture stop is located on the object side, and / or b) the image The center of curvature of the lens surface of the side lens group (G2) directly adjacent to the aperture stop of the third partial lens group (G23) is located on the image side, and
c) A lens system in which the following conditions are satisfied with respect to the radius of curvature R of each lens surface.

  A lens system according to any one of claims 1 to 10, wherein the image circle diameter 2y 'is between 80 mm and 100 mm with diffraction limited imaging performance.   A macro lens (1001, 1002, 1003) comprising the lens system (1, 2, 3) according to any one of claims 1 to 11.   An optical inspection system (2000) for an object, comprising a macro lens according to claim 12.

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