Finity-corrected microscope objective for scanning applications
A finity-corrected microscope objective for scanning applications has a numerical aperture of at least and an object field diameter of at least 1 mm. The objective is apochromatically corrected over a spectral bandwidth of at least 200 nm. A distance between an object plane and an intermediate image plane conjugated thereto is not more than 250 mm.
1 . A microscope objective, comprising:
a first lens group with a positive refractive power;
a second lens group with a positive refractive power; and
a third lens group with a negative refractive power,
wherein the microscope objective:
has a numerical aperture of at least 0.9;
has less than 5% vignetting;
is apochromatically corrected over a spectral bandwidth of at least 200 nanometers (nm);
has an object plane;
has an intermediate image plane conjugated to the object plane;
has an object field diameter of at least 1 millimeter (mm);
has a distance between the object plane and the intermediate image plane that is not more than 250 mm; and
is a finity-corrected microscope objective configured to be used in scanning applications.
2 . The microscope objective of claim 1 , wherein the object field diameter is at least 1.5 mm.
3 . The microscope objective of claim 1 , wherein the microscope objective has a Strehl ratio of at least 0.8 over at least 70% of a field of view of the microscope objective.
4 . The microscope objective of claim 1 , wherein the microscope objective comprises a maximum of 18 optical elements.
5 . The microscope objective of claim 1 , wherein the microscope objective is a dry objective.
6 . The microscope objective of claim 1 , wherein the microscope objective has a chief ray angle on an image side that is not more than 5°.
7 . The microscope objective of claim 1 , wherein a distance between a rearmost optical surface of the microscope objective and the intermediate image plane is at least 50 mm.
8 . The microscope objective of claim 1 , wherein the microscope objective is apochromatically corrected over a bandwidth of at least 200 nm in a wavelength range between 400 nm and 800 nm.
9 . The microscope objective of claim 1 , wherein:
the third lens group comprises first, second and third subgroups;
the first subgroup has a positive refractive power;
the second subgroup has a negative refractive power; and
the third subgroup has a negative refractive power.
10 . The microscope objective of claim 1 , wherein the microscope objective does not have aspheric lenses.
11 . The microscope objective of claim 1 , wherein the microscope objective has the following optical design data (in reverse order):
Surface No.
r (mm)
d (mm)
nd
vd
Image
59.610
1
−29.979
4.063
1.638
42.41
2
−26.122
5.351
1.488
70.41
3
−62.246
20.317
4
20.872
6.694
2.003
28.27
5
14.366
12.936
6
−18.113
1.625
1.613
44.50
7
35.512
10.746
1.569
71.34
8
−26.862
0.888
9
213.454
1.474
1.558
54.01
10
33.083
10.658
1.728
28.53
11
−222.471
0.557
12
142.402
14.900
1.659
71.34
13
−27.102
1.000
1.613
44.49
14
−53.143
0.433
15
107.303
12.568
1.497
81.55
16
−27.221
1.000
1.638
42.41
17
−112.216
0.962
18
23.244
10.344
1.659
71.34
19
−1231.237
1.000
1.855
24.80
20
19.168
5.698
1.659
71.34
21
74.601
0.206
22
12.168
7.337
1.755
52.32
23
10.368
2.766
24
8.315
5.582
1.883
40.76
25
11.242
1.096.
12 . The microscope objective of claim 1 , wherein the object field diameter is at least 1.5 mm, and the microscope objective has a Strehl ratio of at least 0.8 over at least 70% of a field of view of the microscope objective.
13 . The microscope objective of claim 1 , wherein the object field diameter is at least 1.5 mm, and the microscope objective comprises a maximum of 18 optical elements.
14 . The microscope objective of claim 1 , wherein the object field diameter is at least 1.5 mm, and the microscope objective is a dry objective.
15 . The microscope objective of claim 1 , wherein the object field diameter is at least 1.5 mm, and the microscope objective has a chief ray angle on an image side that is not more than 5°.
16 . The microscope objective of claim 1 , wherein the object field diameter is at least 1.5 mm, and a distance between a rearmost optical surface of the microscope objective and the intermediate image plane is at least 50 mm.
17 . A microscope, comprising:
a microscope objective according to claim 1 .
18 . The microscope of claim 17 , wherein the microscope has a footprint of at most 250 mm×200 mm.
19 . The microscope of claim 17 , wherein the microscope is an automated scanning device.
20 . A method, comprising:
using a microscope to acquire at least two images of different sections of a sample, the sections comprising an overlap region; and
assembling the images into a mosaic image,
wherein the microscope comprises a microscope objective according to claim 1 .