DE102017106837B4 - Lens system for a macro lens for industrial use in quality assurance in the production process, macro lens and system - Google Patents

Abstract

Lens system (1) for a macro lens for industrial use in quality assurance in the production process, with a) an object-side lens group (G1), an image-side lens group (G2) and an aperture stop (APE) located in between, wherein b) the object-side lens group (G1) of the object side to the image side has a first lens subgroup (G11) with a positive refractive power, a second lens subgroup (G12) with a negative refractive power and a third lens subgroup (G13) with a positive refractive power,c) the image side lens group (G2) from the object side to the image side has a first lens subgroup (G23) with a positive refractive power, a second lens subgroup (G22) with a negative refractive power and a third lens subgroup (G21) with a positive refractive power, whereind) in at least one of the lens subgroups an optical element has an anomalous partial dispersion of |ΔPg,F| ≥ 0.01.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a lens system for a macro lens for industrial use in quality assurance in the production process, for example in the manufacture of displays, a macro lens with such a lens system and a system for optically checking objects with such a macro lens.

2. Description of the Prior Art

Industrial macro lenses are used in quality assurance. An object to be tested, such as a display extending over a specific area, is scanned in a scanning process using a test setup. To capture the entire width of the object, a large number of inspection units, i.e. cameras with lenses, are arranged in an inspection row. For example, the information obtained in this way can be transmitted to an existing network and thus to a central evaluation unit via a standardized interface such as GigE Vision.

An attempt is made to keep the number of inspection units per inspection series as low as possible while maintaining the same object resolution. A small number of inspection units per inspection series keeps the adjustment effort, the acquisition costs and the associated infrastructure low with the same inspection quality.

One way of keeping the number of inspection units small is to use lenses with very good imaging performance and a large image circle diameter. The investment costs in such a lens must not overcompensate for the savings associated with a small number of inspection units.

Industrial macro lenses currently available for the purpose mentioned have an image circle diameter of 60 mm for the required imaging performance. However, if such lenses are used to illuminate a sensor with an image circle diameter of up to 80 mm, significant field aberrations will already occur. As a result, the inspection quality is reduced in an undesired manner at the edge of the image field.

Adequate correction of the primarily field-dependent aberrations, such as field curvature or astigmatism, cannot be achieved with the known macro lens structures. As a result, the image circle diameters are limited to a maximum of 2y' = 80 mm with noticeable reductions in image quality at the edge of the image field.

The pamphlet DE 30 20 623 A1 discloses a lens with six individual lenses, which is constructed symmetrically around an aperture.

SUMMARY OF THE INVENTION

It is an object of the invention to specify a lens system for a macro lens for the stated application, which offers a larger image circle diameter than the lenses currently known.

Furthermore, it is an object to specify a lens system for a macro lens that offers better imaging performance for existing inspection stations with a specified optical transmission length, ie the distance between object and image, and a specified imaging scale.

The object is achieved by a lens system for a macro lens having the features of independent claim 1, by a macro lens with such a lens system and by a system for optically checking objects with such a macro lens. Further developments of the invention are specified in the dependent claims.

The lens system according to the invention has an object-side lens group, an image-side lens group and an aperture diaphragm located between them. The object-side lens group has from the image side to the object side, a first lens subgroup with a positive refractive power, a second lens subgroup with a negative refractive power and a third lens subgroup with a positive refractive power. The image-side lens group includes, from the object side to the image side, a first lens sub-group having a positive refractive power, a second lens sub-group having a negative refractive power, and a third lens sub-group having a positive refractive power. The two lens groups are therefore made up of lens subgroups whose refractive power distribution is arranged positive-negative-positive symmetrically around the aperture diaphragm. It is further provided that in at least one of the lens subgroups, preferably in all lens subgroups, an optical element has an anomalous partial dispersion of |ΔPg,F| ≥ 0.01. A spectrally very broad correction, in particular a reduced secondary spectrum, can thus be achieved.

• Die erste Linsenuntergruppe der objektseitigen Linsengruppe aus ein zwei Einzellinsen.

In preferred embodiments of the lens system, the following features can be provided alone or in any combination:

• The first lens subgroup of the object-side lens group consists of two individual lenses.

The second lens subgroup of the lens group on the object side essentially consists of one to three individual lenses or a cemented component.

The third lens subgroup of the object-side lens group essentially consists of a single lens and/or a cemented component.

The first lens subgroup of the image-side lens group essentially consists of one or two individual lenses.

The second lens subgroup of the image-side lens group essentially consists of one to three individual lenses or a cemented component.

The third lens subgroup of the image-side lens group essentially consists of a single lens and/or a cemented component.

The expression "consists essentially of" means that the optical lens system may, in addition to the lenses mentioned above as a component, also have lenses whose absolute focal length is greater than or equal to the total focal length of the system and which therefore have practically no refractive power, optical elements other than lenses such as a diaphragm, a mask, a glass cover and/or a filter, mechanical components such as a lens flange, a lens barrel, an imaging element and/or a camera shake correction mechanism.

The imaging scale of the lens system is preferably in an interval from β′=−0.7 to β′=−5.0.

Bevorzugt liegt die bildseitige numerische Apertur des Linsensystems bei NA'≥0.04.It can be provided in particular that for a residual error X of the longitudinal chromatic aberration correction of the lens system within a closed imaging scale interval of [−0.7; -5.0] applies: $\frac{ƒ\text{'}\left(\text{in total}\right)}{X_{430\text{nm}...\text{687nm}}}<\frac{1}{1000}$

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

In a specific embodiment of the lens system, the imaging performance, measured as the standard deviation of the polychromatic wavefront error according to the Marechal criterion—wavefront_RMS≦λ/14′—is only limited by the diffraction.

With the lens system according to the invention, it is possible to avoid the occurrence of artificial vignetting from the center of the sensor to the edge, so that the aperture necessary for diffraction limitation and the desired resolution up to the edge of the sensor are ensured.

In an advantageous embodiment, the ratio between the total focal length f' and the sensor diagonal 2y'(max) satisfies the following condition: $$\frac{2y\text{'}\left(\text{Max}\right)}{ƒ\text{'}\left(Gesamt\right)}\ge 0.8$$

In a likewise advantageous embodiment, the first lens subgroup of the object-side lens group has an object-side meniscus lens. Advantageously, the centers of curvature of the meniscus lens are on the object side of the meniscus lens.

A likewise advantageous embodiment of the lens system provides that the first lens subgroup of the image-side lens group has an image-side meniscus lens. The centers of curvature of the image-side meniscus lens are advantageously located on the image-side of the meniscus lens.

wobei f'(M) die Brennweite der Meniskuslinse und f'(gesamt) die Brennweite des Makroobjektivs ist.The following applies to both the object-side and the image-side meniscus lens: $$\frac{ƒ\text{'}\left(M\right)}{ƒ\text{'}\left(Gesamt\right)\ge \left|2.4\right|},$$

where f'(M) is the focal length of the meniscus lens and f'(total) is the focal length of the macro lens.

In one embodiment, it can be provided that the following applies to the absolute value of the focal lengths of the outer menisci: $$\left|ƒ\text{'}\left(\ddot{\text{a}}\text{extreme minisks}\right)\right|\le 300mm$$

A development of the invention provides that the center of curvature of the lens surface of the third lens subgroup of the object-side lens group, which is directly adjacent to the aperture stop, is on the object side and/or the center of curvature of the lens surface of the third lens subgroup of the image-side lens group, which is directly adjacent to the aperture stop, is on the image side and the following condition applies to the radius of curvature R of the respective lens surface: $$0\le \frac{ƒ\text{'}\left(Gesamt\right)}{\left|R\right|}\le 2.$$

character list

• 1 einen Linsenschnitt einer ersten Ausführungsform mit einem ersten Abbildungsmaßstab;
• 2 einen Linsenschnitt einer zweiten Ausführungsform mit einem zweiten Abbildungsmaßstab;
• 3 einen Linsenschnitt einer dritten Ausführungsform mit einem dritten Abbildungsmaßstab,
• 4 ein Prüfsystem mit einem Makroobjektiv gemäß einer der 1-3.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. In these show:

• 1 a lens section of a first embodiment with a first imaging scale;
• 2 a lens section of a second embodiment with a second magnification;
• 3 a lens section of a third embodiment with a third magnification,
• 4 a test system with a macro lens according to one of 1-3 .

DESCRIPTION OF PREFERRED EMBODIMENTS

1 shows a first embodiment of a macro lens 1001 with an optical lens system 1 in a true-to-scale lens section. The lens system 1 described here as an embodiment has a magnification β' of -2, is constructed as a two-part lens system and has a first lens group G1 and a second lens group G2 along a central optical axis A, each with three lens subgroups.

The lens subgroups of the first lens group G1 are denoted by G11, G12 and G13, those of the second lens group G2 by G23, G22 and G21. The sequence of the refractive power of the individual lens subgroups is positive - negative - positive in each lens group G1, G2. Concretely, this means that the refractive power of the outer first lens subgroup G11 of the first lens group G1 is positive, the middle second lens subgroup G12 of the first lens group G1 is negative and the inner third lens subgroup G13 of the first lens subgroup G1 is positive.

The refractive power distribution of the second lens group G2 is the same, i.e. the refractive power of the outer first lens subgroup G21 of the second lens group G2 is positive, the middle second lens subgroup G22 of the second lens group G2 is negative and that of the inner third lens subgroup G23 is positive.

An aperture stop APE is provided between the two lens groups G1, G2. The apertures or stops shown in the figures are not necessarily to scale in size and shape, but indicate the position of the stop/aperture along the optical axis A.

The structure of the lens system is now described below from left to right, ie from object side to 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 shortened for reasons of representation. The drawn-in central and edge rays are shown here correspondingly shortened.

The first lens group G11 on the object side has an overall positive refractive power and has a meniscus lens 10 on the object side. The meniscus lens 10 is made of flint glass with an Abbe number v _d of 24.42 and a refractive index n _d of 1.805181. All information regarding Abbe number and refractive index applies to the Fraunhofer line d at the wavelength 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. Like all surfaces of this exemplary embodiment, the concave surface 101 is spherical and has a radius of curvature which can be, for example, -57.8965 mm.

In principle, however, it is true that optical systems such as the one described here can be proportionally enlarged or reduced, for example to adapt to a different image size, and the radii, diameters, thicknesses and distances given here are therefore to be understood only as examples.

The radius of curvature of the image-side convex surface 102 is smaller than the radius of the object-side surface 101 and is -53.4548 mm. The centers of curvature of the two surfaces 101, 102 of the first object-side meniscus lens 10 are on the object side. The distance between the vertices of the two surfaces 101, 102 of the meniscus lens 10 are 7.00 mm apart.

A convex-concave lens 11 is provided as the overall second lens and as the second lens in the lens subgroup G11. The second lens 11 is crown glass with an Abbe number of 67.74 and a refractive index of 1.595220.

The second lens 11 has an object-side first convexly curved surface 111 which has a radius of curvature of 52.9806 mm. The vertex of the convex surface 111 is 2.00 mm away from the vertex of the image-side second surface 102 of the meniscus lens 10 .

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 the first lens subgroup G11 having an overall positive refractive power.

The second lens subgroup G12 has a negative refractive power and essentially consists of a single lens, namely the third lens 12. The third lens 12 is made of flint glass, 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, likewise concavely curved surface 122 has a radius of curvature of 42.5852 mm. The vertex of the image-side surface 122 is 4.00 mm away from the vertex of the object-side surface 121 .

The third lens subgroup G13 has a positive refractive power and essentially consists of a cemented component composed of a fourth lens 13 on the object side and a fifth lens 14 on the image side with different types of glass. The optical properties of the cemented area between the two lenses 13, 14 are not discussed in detail since their influence on the overall system is considered to be negligible.

The fourth lens 13 has a convexly curved surface 131 on the object side, which has a radius of curvature of 135.8602 mm. The vertex of the surface 131 is spaced 8.00 mm from the vertex of the image-side surface 122 of the third lens 12. FIG.

The image-side surface of the fourth lens 13 is identical in geometry to the object-side surface 141 of the fifth lens 14. It is convex in shape in relation to the fifth lens 14 and has a Radius of curvature of 59.0741 mm, its apex is 9.00 mm away from that of the object-side first surface 131 of the fourth lens 13.

The fifth lens 14 is also made of crown glass, 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 also convex in shape, has a radius of curvature of -63.4152 mm, and its apex is 8.00 mm from the apex of the object-side first surface 141 of the fifth lens 14 .

An aperture stop follows the fifth lens 14 at a distance of 1.00 mm.

At a further distance of 1.00 mm is the apex of the object-side first surface 151 of the sixth lens 15, which forms a cemented component together with a seventh lens 16. This cemented component in turn forms the third lens subgroup G23 of the image-side lens group G2.

The radius of curvature of the object-side convex surface 151 is 82.5025 mm, and its vertex is 6.00 mm away from the vertex 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, it has an Abbe number of 67.74 and a refractive index of 1.595220.

The seventh lens 16 is also made of crown glass, has an Abbe number of 56.81 and a refractive index of 1.607379. The already mentioned first surface 161 on the object side has a radius of −67.1127 mm. The vertex of the object-side surface 161 is 5.00 mm away from the vertex of the image-side second convex surface 162 .

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

The cemented element forming the third lens subgroup G23 with positive refractive power is followed at a distance of 10.00 mm--related to the vertices of the surfaces--by the eighth lens 17, which forms the second lens subgroup G22 with negative refractive power.

On the object side, the eighth lens 17 has a concavely curved surface 171 with a radius of curvature of −55.0234 mm, and on the image side there is also a concavely curved surface 172 with a radius of curvature of 68.6862 mm. At their vertices, the surfaces 171, 172 are spaced 4.00mm apart. The eighth lens 17 is made of flint glass with an Abbe number of 42.41 and a refractive index of 1.637750.

The adjoining first lens subgroup G21 of the second lens group G2 essentially consists of two meniscus lenses 18, 19.

The object-side first lens 18 of the first lens subgroup G21 is in turn made from the crown glass of the fifth lens 14 and the sixth lens 15, which has an Abbe number of 67.74 and a refractive index of 1.595220. The object-side surface 181 of the ninth lens 18 is concave-shaped, its apex is 15.00 mm away from the apex of the image-side second surface 172 of the eighth lens 17, and has a radius of curvature of -89.8561 mm. The second image-side surface 182 is convex in shape, has a radius of curvature of -52.0433 mm, and is 7.00 mm away from the vertex of the object-side first surface 181 .

The tenth lens 19 together with the ninth lens 18 forms the first lens subgroup G21. The tenth lens 19 is made of flint glass with an Abbe number of 18.90 and a refractive index of 1.922860. The object-side first convex surface 191 has a radius of curvature of 85.7767. Its vertex is 2.00 mm from the vertex 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; its vertex is 6.00 mm away from the vertex of the first object-side surface 191 .

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

The surface designations, radii, thicknesses and material specifications are clearly summarized in the following table. surface Radius [mm] Thickness or distance [mm] Medium Abbe number medium refractive index OBJ 126.58 10 101 -57.8965 7.00 25.42 1.805181 102 -53.4548 2.00 11 111 52.9806 8.00 67.74 1.595220 112 407.9243 7.00 12 121 -51.8151 4.00 42.41 1.637750 122 42.5825 8.00 13 131 135.8602 9.00 60.64 1.603112 14 141 59.0741 8.00 67.74 1.595220 142 -63.4152 1.00 APE 1.00 15 151 82.5024 6.00 67.74 1.595220 16 161 -76.1127 5.00 56.81 1.607379 162 -54.9014 10.00 17 171 -55.0234 4.00 42.41 1.637750 172 68.6862 15.00 18 181 -89.8561 7.00 67.74 1.595220 182 -52.0433 2.00 19 191 85.7767 6.00 18.90 1.922860 192 88.7231 303.40 BIL

2 shows a second embodiment of a macro lens 1002 of an optical lens system 2 in a true-to-scale lens section. This in 2 The lens system 2 shown has an imaging scale β' of -5. In principle, the lens system has the same structure as the lens system 1 described as the first exemplary embodiment, ie it has two lens groups G1 and G2 each with three lens subgroups G11, G12, G13 or G23, G22, G21. The sequence of the refractive power in the lens subgroups is positive - negative - positive.

• Einer erste Meniskuslinse 20 mit einer objektseitigen konkaven Oberfläche 201 und einer bildseitigen konvexen Oberfläche 202 bildet zusammen mit einer zweiten Linse 21, die eine objektseitige konvexe Oberfläche 211 und eine bildseitige konvexe Oberfläche 222 aufweist, die erste Linsenuntergruppe G11 mit positiver Brechkraft der ersten Linsengruppe G1.

This again results in a lens system with ten lenses. The sequence of the individual lenses from object to image and their association with the lens subgroups are as follows:

• A first meniscus lens 20 with an object-side concave surface 201 and an image-side convex surface 202 forms together with a second lens 21, which has an object-side convex surface 211 and an image-side convex surface 222, the first lens subgroup G11 with positive refractive power of the first lens group G1.

The second lens sub-group G12 is formed by cementing a third lens 22 having an object-side convex surface 221 and a fourth lens 23 having an object-side concave surface 231 and an image-side concave surface 232. The second lens sub-group G12 has a negative refractive power.

The third lens subgroup G13 of the first lens group G1 is formed by a single meniscus lens, namely the fifth lens 24, which has a convex surface 241 on the object side and a concave surface 242 on the image side.

The third lens subgroup G13 of the first lens group G1 is followed by the third lens subgroup G23 with a positive refractive power of the second lens group G2. The aperture stop APE is arranged between the two lens subgroups.

The third lens subgroup G23 of the second lens group G2 consists essentially of a single meniscus lens, namely the sixth lens 25, which has a concave surface 251 on the object side and a convex surface 252 on the image side.

The second lens subgroup G22 of the second lens group G2 in turn has a negative refractive power and includes a cemented component. The cemented element consists essentially of a seventh lens 26 with a concave surface 261 on the object side, the geometry of which largely follows that of the closely adjacent surface 252 of the sixth lens 25 on the image side. On the image side, the object-side convex surface 271 of the eighth lens 27 adjoins via the cemented area, with which the seventh lens 26 forms the cemented component. The eighth lens 27 has a convex surface 272 on the image side.

The first lens subgroup G21 of the second lens group G2 has a positive refractive power and essentially consists of a biconvex ninth lens 28 with an object-side surface 281 and an image-side surface 282 as well as a meniscus lens 29 with an object-side convex surface 291 and a concave image-side surface 292 .

The radii of curvature, thicknesses and glass parameters of the lenses are shown in the table below: surface Radius [mm] Thickness or distance [mm] Medium Abbe number medium refractive index OBJ 55.790000 20 201 -29.457900 11:48 55.89 1.651130 202 -41.2306 4.4 21 211 140.8312 18.75 94.93 1.438750 212 -54.3099 0.1 22 221 42.6238 14.90 81.54 1.496999 23 231 -38.2808 4.34 64:14 1.516330 232 30.1698 6.097915 24 241 119.3927 3.38 40.51 1.730770 242 281.9272 2.41 APE 7.63 25 251 -28.6462 6.66 18.90 1.922860 252 -31.9763 1.02 26 261 -34.4893 10.04 47.23 1.54072 27 271 100.6113 14.68 94.93 1.438750 272 -52.4873 2.02 28 281 134.5050 19:47 81.54 1.496999 282 -74.2924 4.09 29 291 86.1528 6.99 54.68 1.729157 292 61.1084 585.11 BIL

3 shows a third embodiment of a macro lens 1003 of the optical lens system 3 in a true-to-scale lens section. This in 3 The lens system 3 shown has an imaging scale β' of -0.7. In principle, the lens system again has the same structure as the previous one described two embodiments. It can be divided into two lens groups G1, G2, each of which has three lens subgroups G11, G12, G13 or G23, G22, G21. In the lens subgroups, the refractive power sequence is positive - negative - positive.

• Die erste Linsenuntergruppe G11 der ersten Linsengruppe G1 weist eine positive Brechkraft auf und besteht im Wesentlichen aus einer ersten objektseitigen Meniskuslinse 30 mit einer objektseitigen konvexen Oberfläche 301 und einer bildseitigen konkaven Oberfläche 302 sowie einer bildseitigen zweiten Meniskuslinse 31 mit einer objektseitigen konvexen Oberfläche 311 und einer bildseitigen konkaven Oberfläche 312.

The lens system 3 has thirteen lenses, four of which are joined to form two cemented elements. The sequence of the individual lenses from object to image and their association with the lens subgroups are as follows:

• The first lens subgroup G11 of the first lens group G1 has a positive refractive power and essentially consists of a first object-side meniscus lens 30 with an object-side convex surface 301 and an image-side concave surface 302 and an image-side second meniscus lens 31 with an object-side convex surface 311 and an image-side concave surface 312.

The second lens subgroup G12 of the first lens group G1 has an overall negative refractive power and essentially consists of two individual lenses. A 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 lens subgroup G13 of the first lens group G1 has an overall positive refractive power and essentially consists of a cemented component and a biconcave single lens. The cemented element is composed of a fifth lens 34 with a convex surface 341 on the object side and a sixth lens 35, which has a convex surface 351 on the object side, to which the fifth lens 34 is cemented, and a concave surface 352 on the image side. The other individual lens belonging to the third lens group G13 is the seventh biconcave lens 36 with an object-side surface 361 and an image-side surface 362.

The third lens sub-group G23 of the second lens group G2 is formed of a cemented component composed of the eighth lens 37 and the ninth lens 38 with a positive refractive power. The eighth lens 37 is biconvex with an object-side surface 371, the ninth lens 38 is meniscus-shaped with a concave object-side surface 381 to which the eighth lens 37 is cemented on the object side, and a convex image-side surface 382.

The second lens subgroup G22 of the second lens group G2 is composed of the tenth lens 39 and the eleventh lens 40, which together have a negative refractive power. The tenth lens 39 is biconcave with an object-side surface 391 and an image-side surface 392, the eleventh lens 40 is designed as a meniscus lens with a convex object-side surface 401 and an object-side concave surface 402.

The first lens subgroup G21 of the second lens group G2 consists essentially of two meniscus lenses 41, 42. The first of these meniscus lenses on the object side forms the twelfth lens 41, which has a concave surface 411 on the object side and a convex surface 412 on the image side. The second, image-side meniscus lens is the thirteenth lens 42, which also has a concave surface 421 on the object side and a convex surface 422 on the image side.

The radii of curvature, thicknesses and glass parameters of the lenses are shown in the table below: surface Radius [mm] Thickness or distance [mm] Medium Abbe number medium refractive index OBJ 247.95 30 301 65.8101 4.10 20.88 1.922860 302 72.1429 0.10 31 311 32.9506 4.59 56.65 1.607381 312 25.3506 21:48 32 321 -36.5855 5.37 42.41 1.637750 322 -46.6728 0.10 33 331 -407.6229 2.99 42.41 1.637750 332 103.5969 0.10 34 341 50.9480 3.00 57.05 1.622799 35 351 26.5492 6.79 58.90 1.518229 352 324.3110 3.46 36 361 122.8624 5.98 67.74 1.595220 362 -74.9701 0.10 APE 0.10 37 371 62.3316 13.00 67.74 1.595220 38 381 -25.6438 5.34 55.98 1.568827 382 -82.5525 0.91 39 391 -117.5077 2.00 42.41 1.637750 392 42.2998 5.88 40 401 69.6743 4.00 56.36 1.568832 402 107.6364 17.88 41 411 -24.8805 6.00 55.98 1.568827 412 -36.6264 0.1 42 421 -67.5202 4.68 27.51 1.755199 422 -52.4329 154.07 BIL

4 12 illustrates an inspection system 2000. The inspection system 2000 is designed for the optical inspection of surfaces of objects 2001. The surfaces to be inspected preferably extend in one plane. The surfaces to be inspected can be displays, for example.

The test system 2000 has an inspection camera arrangement 2005 with a number of inspection cameras 2006, each with a macro lens 1001 with a lens system. Depending on the application, another macro lens 1002, 1003 or a macro lens with another suitable focal length according to the invention can also be used. The number of inspection cameras 2006 is in the in 4 shown embodiment arranged as row 2008.

In this embodiment, the inspection system 2000 has a conveying device 2004 which, in this embodiment, conveys the object 2001 to be inspected horizontally along a conveying direction 2002 relative to the row 2008 , in particular perpendicularly to the row 2008 . The conveyor device 2004 can be a conveyor belt or a displacement table, for example. Of course, the conveying device 2004 can also be designed for a conveying movement in directions other than horizontal. Furthermore, alternatively, instead of moving the object 2001, the inspection camera arrangement 2005 can be moved relative to the object 2001 to be inspected.

Claims (12)

Lens system (1) for a macro lens for industrial use in quality assurance in the production process, with a) an object-side lens group (G1), an image-side lens group (G2) and an aperture stop (APE) located in between, where b) the object-side lens group (G1 ) from the object side to the image side, a first lens subgroup (G11) with a positive refractive power, a second lens subgroup (G12) with a negative refractive power and a third lens subgroup (G13) with a positive refractive power, c) the image side lens group (G2) from the object side to the image side has a first lens subgroup (G23) with a positive refractive power, a second lens subgroup (G22) with a negative refractive power and a third lens subgroup (G21) having a positive refractive power, wherein d) in at least one of the lens subgroups an optical element has an anomalous partial dispersion of |ΔPg,F| ≥ 0.01. lens system claim 1 , wherein a) the first lens subgroup (G11) of the object-side lens group consists of one or two individual lenses (10, 11), b) the second lens subgroup (G12) of the object-side lens group consists of one to three individual lenses (12) or a cemented component, c) the third lens subgroup (G13) of the object-side lens group consisting of an individual lens and/or a cemented component (13, 14), d) the first lens subgroup (G21) of the image-side lens group consisting of one or two individual lenses (18, 19), e) the second lens subgroup ( G22) the image-side lens group is constructed from one to three individual lenses (17) or a cemented component, and/or f) the third lens subgroup (G23) of the image-side lens group is constructed from a single lens and/or a cemented component (15, 16). Lens system according to one of the preceding claims, wherein the imaging scale of the lens system (1) lies in an interval from β'=-0.7 to β'=-5.0. Lens system according to one of the preceding claims, wherein for a residual error X of the longitudinal chromatic aberration correction of the lens system within a closed magnification interval of [-0.7; -5.0] applies: $$\frac{ƒ\text{'}\left(Gesamt\right)}{X_{430\text{nm}...\text{687nm}}}<\frac{1}{1000}.$$

Lens system according to one of the preceding claims, wherein the following applies to the image-side numerical aperture NA': NA'≥0.04. Lens system according to one of the preceding claims, wherein the imaging performance, measured as the standard deviation of the polychromatic wavefront error according to the Marechal criterion - wavefront_RMS ≤ λ/14' - is only limited by the diffraction. Lens system according to one of the preceding claims, wherein the following relationship applies between the total focal length f' of the lens system and a sensor diagonal 2y'(max): $$\frac{2\text{'}\left(\text{Max}\right)}{ƒ\text{'}\left(Gesamt\right)}\ge 0.8$$

Lens system according to one of the preceding claims, wherein a) the first lens subgroup (G11) of the object-side lens group (G1) has an object-side meniscus lens (10) and wherein the centers of curvature of the object-side meniscus lens (10) are on the object side of the meniscus lens (10) and/or b ) the first lens subgroup (G21) of the image-side lens group (G2) has an image-side meniscus lens (19) and the centers of curvature of the image-side meniscus lens (19) are on the image-side of the meniscus lens (19) and the following condition applies: c) $\frac{ƒ\text{'}\left(M\right)}{ƒ\text{'}\left(Gesamt\right)}\ge \left|2.4\right|,$

where f(M) is the focal length of the meniscus lens and f'(total) is the focal length of the macro lens. Lens system according to one of the preceding claims, wherein a) the center of curvature of the lens surface of the third lens subgroup (G13) of the object-side lens group, which is directly adjacent to the aperture stop, is on the object side and/or b) the center of curvature of the lens surface of the third lens subgroup (G23) of the image-side lens group (G2), which is immediately adjacent to the aperture stop, is on the image side and c) the following condition applies to the radius of curvature R of the respective lens surface: $$0\le \frac{ƒ\text{'}\left(Gesamt\right)}{\left|R\right|}\le 2.$$

Lens system according to one of the preceding claims, in which the image circle diameter 2y' is between 80 mm and 100 mm with diffraction-limited imaging performance. Macro lens (1001, 1002, 1003) with a lens system (1, 2, 3) according to one of the preceding claims. System (2000) for optically checking objects with a macro lens claim 11 .

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