Parfocal low-magnification microscope objective lens systems

Claim 2

A parfocal low-magnification microscope objective lens system comprising: a positive first lens member disposed at a position nearest to the object and with its convex surface facing the object; a negative second lens member disposed at a position farther from said object than said first lens member and including at least one negative meniscus lens component having its convex surface facing the object side; and a third positive lens member disposed at a position farthest from said object and including a positive lens component with that surface thereof sharper in radius of curvature facing the image plane side; said lens system satisfying the following four conditions: d.sub.A< f.sub.A < d.sub.A +| f.sub.Z| ( 1) d.sub.A < d.sub.B ( 2), |f.sub.B|<| f.sub.A| ( 3), ↑d.sub.B|<| f.sub.B| ( 4), where f A is the composite focal length of the first lens member, f B is the composite focal length of the second lens member, d A is a rear focal plane of the first lens member to front focal plane of the second lens member distance, and d B is a rear focal plane of the second lens member to front focal plane of the third lens member distance, the parameters of said system having the following values: ______________________________________ WD= 5.5 1st R.sub.1 = 14.8 member d.sub.1 = 2.2 n.sub.1 = 1.58913 νd.sub.1 = 61.2 (A) R.sub.2 = -600.0 d.sub.2 = 13.1 R.sub.3 = 45.0 2nd d.sub.3 = 3.0 n.sub.2 = 1.74077 νd.sub.2 = 27.7 member R.sub.4 = -16.0 (B) d.sub.4 = 0.5 n.sub.3 = 1.713 νd.sub.3 = 53.9 R.sub.5 = 5.487 d.sub.5 = 16.7 R.sub.6 = -54.8 d.sub.6 = 2.8 n.sub.4 = 1.51823 νd.sub.4 = 59.0 R.sub.7 = -12.7 3rd d.sub.7 = 0.1 member R.sub.8 = 360.0 (C) d.sub.8 = 1.0 n.sub.5 = 1.7495 νd.sub.5 = 35.0 R.sub.9 = 18.85 d.sub.9 = 3.1 n.sub.6 = 1.50032 νd.sub.6 = 81.9 R.sub.10 = -20.38 ______________________________________ wherein R 1 , R 2 , . . . . are the radii of curvature of the individual surfaces, d 1 , d 2 . . . . are the axial thickness or spacing of the individual elements, WD is the axial distance from the object to the first surface of the lens system, n 1 , n 2 . . . . are the refractive indexes of the individual elements and νd 1 , νd 2 , . . . . are the Abbe numbers of the individual elements.

Claim 3

A parfocal low-magnitication microscope objective lens system comprising: a positive first lens member disposed at a position nearest to the object and with its convex surface facing the object; a negative second lens member disposed at a position farther from said object than said first lens member and including at least one negative meniscus lens component having its convex surface facing the object side; and a third positive lens member disposed at a position farthest from said object and including a positive lens component with that surface thereof sharper in radius of curvature facing the image plane side; said lens system satisfying the following four conditions: d.sub.A < f.sub.A< d.sub.A +| f.sub.B| ( 1), d.sub.A < d.sub.B ( 2), |f.sub.b|<| f.sub.A| ( 3), |d.sub.B|< f.sub.B| ( 4), where f A is the composite focal length of the first lens member, f B is the composite focal length of the second lens member, d A is a rear focal plane of the first lens member to front focal plane of the second lens member distance, and d B is a rear focal of the second lens member to front focal plane of the third lens member distance, the parameters of said system having the following values: __________________________________________________________________________ WD = 4.0 1st R.sub.1 = 17.0 member d.sub.1 = 2.5 n.sub.1 = 1.65128 νd.sub.1 = 38.3 (A) R.sub.2 = -95.5 d.sub.2 = 10.0 R.sub.3 = 18.1 d.sub.3 = 2.5 n.sub.2 = 1.76182 νd.sub.2 = 26.5 R.sub.4 = -21.2 2nd d.sub.4 = 0.8 n.sub.3 = 1.51823 νd.sub.3 = 59.0 member R.sub.5 = 4.62 (B) d.sub.5 = 4.0 R.sub.6 = -7.956 d.sub.6 = 2.0 n.sub.4 = 1.7495 νd.sub.4 = 35.0 R.sub.7 = -20.8 d.sub. 7 = 14.5 R.sub.8 = -53.1 d.sub.8 = 3.5 n.sub.5 = 1.58894 νd.sub.5 = 61.04 R.sub.9 = -16.559 3rd d.sub.9 = 0.3 member R.sub.10 = 70.1 (C) d.sub.10 = 1.4 n.sub.6 = 1.71736 νd.sub.6 = 29.5 R.sub.11 = 21.0 d.sub.11 = 3.3 n.sub.7 = 1.50032 νd.sub.7 = 81.9 R.sub.12 = - 26.584 __________________________________________________________________________ where R 1 , R 2 , . . . are the radius of curvature of the individual surfaces, d 1 , d 2 . .. . are the axial thickness or spacing of the individual elements, WD is the axial distance from the object to the first surface of the lens system, n 1 , n 2 , . . . are the refractive indexes of the individual elements and νd 1 , νd 2 , . . . are the Abbe numbers of individual elements.

Claim 4

A parfocal low-magnitication microscope objective lens system comprising: a positive first lens member disposed at a position nearest to the object and with its convex surface facing the object; a negative second lens member disposed at a position farther from said object than said first lens member and including at least one negative meniscus lens component having its convex surface facing the object side; and a third positive lens member disposed at a position farthest from said object and including a positive lens component with that surface thereof sharper in radius of curvature facing the image plane side; said lens system satisfying the following four conditions: d.sub.A < f.sub.A< d.sub.A +| f.sub.B| ( 1), d.sub.A < d.sub.B ( 2), |f.sub.b|<| f.sub.A| ( 3), |d.sub.B|< f.sub.B| ( 4), where f A is the composite focal length of the first lens member, f B is the composite focal length of the second lens member, d A is a rear focal plane of the first lens member to front focal plane of the second lens member distance, and d B is a rear focal of the second lens member to front focal plane of the third lens member distance, the parameters of said system having the following values: __________________________________________________________________________ WD = 4.0 1st R.sub.1 = 17.0 member d.sub.1 = 2.5 n.sub.1 = 1.65128 νd.sub.1 = 38.3 (A) R.sub.2 = -95.5 d.sub.2 = 10.0 R.sub.3 = 18.1 d.sub.3 = 2.5 n.sub.2 = 1.76182 νd.sub.2 = 26.5 R.sub.4 = -21.2 2nd d.sub.4 = 0.8 n.sub.3 = 1.51823 νd.sub.3 = 59.0 member R.sub.5 = 4.62 (B) d.sub.5 = 4.0 R.sub.6 = -7.956 d.sub.6 = 2.0 n.sub.4 = 1.7495 νd.sub.4 = 35.0 R.sub.7 = -20.8 d.sub. 7 = 14.5 R.sub.8 = -53.1 d.sub.8 = 3.5 n.sub.5 = 1.58894 νd.sub.5 = 61.04 R.sub.9 = -16.559 3rd d.sub.9 = 0.3 member R.sub.10 = 70.1 (C) d.sub.10 = 1.4 n.sub.6 = 1.71736 νd.sub.6 = 29.5 R.sub.11 = 21.0 d.sub.11 = 3.3 n.sub.7 = 1.50032 νd.sub.7 = 81.9 R.sub.12 = - 26.584 __________________________________________________________________________ where R 1 , R 2 , . . . are the radius of curvature of the individual surfaces, d 1 , d 2 . .. . are the axial thickness or spacing of the individual elements, WD is the axial distance from the object to the first surface of the lens system, n 1 , n 2 , . . . are the refractive indexes of the individual elements and νd 1 , νd 2 , . . . are the Abbe numbers of individual elements.

Claim 5

A parfocal low-magnification microscope objective lens system comprising: a positive first lens member disposed at a position nearest to the object and with its convex surface facing the object; a negative second lens member disposed at a position farther from said object than said first lens member and including at least one negative meniscus lens component having its convex surface facing the object side; and a third positive lens member disposed at a position farthest from said object and including a positive lens component with that surface thereof sharper in radius of curvature facing the image plane side; said lens system satisfying the following four conditions: d.sub.A< f.sub.A < d.sub.A +| f.sub.B| ( 1), d.sub.A < d.sub.B ( 2), |f.sub.B|<| f.sub.A| ( 3), ↑d.sub.B|<| f.sub.B| ( 4) where f A is the composite focal length of the first lens member, f B is the composite focal length of the second lens member, d A is a rear focal plane of the first lens member to front focal plane of the second lens member distance, and d B is a rear focal plane of the second lens member to front focal plane of the third lens member distance, the parameters of said system having the following values: __________________________________________________________________________ WD = 2.0 R.sub.1 = 16.3 d.sub.1 = 2.9 n.sub.1 = 1.713 νd.sub.1 = 53.9 1st R.sub.2 = 74.0 member d.sub.2 = 0.2 (A) R.sub.3 = 17.0 d.sub.3 = 1.7 n.sub.2 = 1.62004 νd.sub.2 = 36.3 R.sub.4 = 24.0 d.sub.4 = 8.8 R.sub.5 = 27.0 d.sub.5 = 2.4 n.sub.3 = 1.76182 νd.sub.3 = 26.5 R.sub.6 = -8.0 2nd d.sub.6 = 0.8 n.sub.4 = 1.74443 νd.sub.4 = 49.4 member R.sub.7 = 5.72 (B) d.sub.7 = 7.8 R.sub.8 = -5.03 d.sub.8 = 1.0 n.sub.5 = 1.74443 νd.sub.5 = 49.4 R.sub.9 = -27.0 d.sub.9 = 15.2 R.sub.10 = -110.0 d.sub.10 = 0.8 n.sub.6 = 1.7495 νd.sub.6 = 35.0 R.sub.11 = 27.84 d.sub.11 = 2.1 n.sub.7 = 1.58894 νd.sub.7 = 61.04 3rd R.sub.12 = -17.335 member d.sub.12 = 0.2 (C) R.sub.13 = 51.0 d.sub.13 = 0.8 n.sub.8 = 1.67163 νd.sub.8 = 38.8 R.sub.14 = 25.3 d.sub.14 = 2.2 n.sub.9 = 1.50032 νd.sub.9 = 81.9 R.sub.15 = -24.419 __________________________________________________________________________ where R 1 , R 2 , . . . are the radii of curvature of the individual surfaces, d 1 , d 2 , . . . are the axial thickness or spacing of the individual elements, WD is the axial distance from the object to the first surface of the lens system, n 1 , n 2 , . . . . are the refractive indexes of the individual elements and νd 1 , ∥d 2 , . . . are the Abbe numbers of individual elements.

Claim 6

A parfocal low-magnification microscope objective lens system comprising: a positive first lens member disposed at a position nearest to the object and with its convex surface facing the object; a negative second lens member disposed at a position farther from said object than said first lens member and including at least one negative meniscus lens component having its convex surface facing the object side; and a third positive lens member disposed at a position farthest from said object and including a positive lens component with that surface thereof sharper in radius of curvature facing the image plane side; said lens system satisfying the following four conditions: d.sub.A< f.sub.A < d.sub.A +| f.sub.B| ( 1), d.sub.A < d.sub.B ( 2), |f.sub.B|<| f.sub.A| ( 3), ↑d.sub.B|<| f.sub.B| ( 4) where f A is the composite focal length of the first lens member, f B is the composite focal length of the second lens member, d A is a rear focal plane of the first lens member to front focal plane of the second lens member distance, and d B is a rear focal plane of the second lens member to front focal plane of the third lens member distance, the parameters of said system having the following values: __________________________________________________________________________ WD = 2.0 R.sub.1 = 16.3 d.sub.1 = 2.9 n.sub.1 = 1.713 νd.sub.1 = 53.9 1st R.sub.2 = 74.0 member d.sub.2 = 0.2 (A) R.sub.3 = 17.0 d.sub.3 = 1.7 n.sub.2 = 1.62004 νd.sub.2 = 36.3 R.sub.4 = 24.0 d.sub.4 = 8.8 R.sub.5 = 27.0 d.sub.5 = 2.4 n.sub.3 = 1.76182 νd.sub.3 = 26.5 R.sub.6 = -8.0 2nd d.sub.6 = 0.8 n.sub.4 = 1.74443 νd.sub.4 = 49.4 member R.sub.7 = 5.72 (B) d.sub.7 = 7.8 R.sub.8 = -5.03 d.sub.8 = 1.0 n.sub.5 = 1.74443 νd.sub.5 = 49.4 R.sub.9 = -27.0 d.sub.9 = 15.2 R.sub.10 = -110.0 d.sub.10 = 0.8 n.sub.6 = 1.7495 νd.sub.6 = 35.0 R.sub.11 = 27.84 d.sub.11 = 2.1 n.sub.7 = 1.58894 νd.sub.7 = 61.04 3rd R.sub.12 = -17.335 member d.sub.12 = 0.2 (C) R.sub.13 = 51.0 d.sub.13 = 0.8 n.sub.8 = 1.67163 νd.sub.8 = 38.8 R.sub.14 = 25.3 d.sub.14 = 2.2 n.sub.9 = 1.50032 νd.sub.9 = 81.9 R.sub.15 = -24.419 __________________________________________________________________________ where R 1 , R 2 , . . . are the radii of curvature of the individual surfaces, d 1 , d 2 , . . . are the axial thickness or spacing of the individual elements, WD is the axial distance from the object to the first surface of the lens system, n 1 , n 2 , . . . . are the refractive indexes of the individual elements and νd 1 , ∥d 2 , . . . are the Abbe numbers of individual elements.

Claim 7

A parfocal low-magnification microscope objective lens system comprising: a positive first lens member disposed at a position nearest to the object and with its convex surface facing the object; a negative second lens member disposed at a position farther from said object than said first lens member and including at least one negative meniscus lens component having its convex surface facing the object side; and a third positive lens member disposed at a position farthest from said object and including a positive lens component with that surface thereof sharper in radius of curvature facing the image plane side; said lens system satisfying the following four conditions: d.sub.A< f.sub.A< d.sub.A +| f.sub.B| ( 1), d.sub.A< d.sub.B ( 2), |f.sub.B|<| f.sub.A| ( 3), |d.sub.B|˜|< f.sub.B|( 4), where f A is the composite focal length of the first lens member, f B is the composite focal length of the second lens member, d A is a rear focal plane of the first lens member to front focal plane of the second lens member distance, and d B is a rear focal plane of the second lens member to front focal plane of the third lens member distance, the parameters of said system having the following values: __________________________________________________________________________ WD = 2.1 R.sub.1 = 26.3 d.sub.1 = 3.2 n.sub.1 = 1.6228 νd.sub.1 = 56.9 R.sub.2 = -320.0 1st d.sub.2 = 0.1 member R.sub.3 = 14.2 (A) d.sub.3 = 2.2 n.sub.2 = 1.62041 νd.sub.2 = 60.3 R.sub.4 = 21.0 d.sub.4 = 15.0 R.sub.5 = 21.0 d.sub.5 = 1.5 n.sub.3 = 1.7552 νd.sub.3 = 27.5 R.sub.6 = -9.0 2nd d.sub.6 = 0.7 n.sub.4 = 1.713 νd.sub.4 = 53.9 member R.sub.7 = 9.0 (B) d.sub.7 = 0.5 R.sub.8 = -9.0 d.sub.8 = 0.8 n.sub.5 = 1.713 νd.sub.5 = 53.9 R.sub.9 = 4.6 d.sub.9 = 16.5 R.sub.10 = -51.0 d.sub.10 = 2.0 n.sub.6 = 1.62374 νd.sub.6 = 47.0 R.sub.11 = -13.32 3rd d.sub.11 = 0.1 member R.sub.12 = 105.0 (C) d.sub.12 = 0.6 n.sub.7 = 1.74 νd.sub.7 = 28.2 R.sub.13 = 17.0 d.sub.13 = 3.2 n.sub.8 = 1.50032 νd.sub.8 = 81.9 R.sub.14 = -20.28 __________________________________________________________________________ where R 1 , R 2 , . . . are the radii of curvature of the individual surfaces, d 1 , d 2 , . . . are the axial thickness or spacing of individual elements, WD is the axial distance from the object to the first surface of the lens system, n 1 , n 2 , . . . are the refractive indexes of the individual elements and νd 1 , νd 2 , . . . are the Abbe numbers of individual elements.

Claim 8

A parfocal low-magnification microscope objective lens system comprising: a positive first lens member disposed at a position nearest to the object and with its convex surface facing the object; a negative second lens member disposed at a position farther from said object than said first lens member and including at least one negative meniscus lens component having its convex surface facing the object side; and a third positive lens member disposed at a position farthest from said object and including a positive lens component with that surface thereof sharper in radius of curvature facing the image plane side; said lens system satisfying the following four conditions: d.sub.A< f.sub.A< d.sub.A +| f.sub.B| ( 1), d.sub.A< d.sub.B ( 2), |f.sub.B|<| f.sub.A| ( 3), |d.sub.B|˜|< f.sub.B|( 4), where f A is the composite focal length of the first lens member, f B is the composite focal length of the second lens member, d A is a rear focal plane of the first lens member to front focal plane of the second lens member distance, and d B is a rear focal plane of the second lens member to front focal plane of the third lens member distance, the parameters of said system having the following values: __________________________________________________________________________ WD = 2.1 R.sub.1 = 26.3 d.sub.1 = 3.2 n.sub.1 = 1.6228 νd.sub.1 = 56.9 R.sub.2 = -320.0 1st d.sub.2 = 0.1 member R.sub.3 = 14.2 (A) d.sub.3 = 2.2 n.sub.2 = 1.62041 νd.sub.2 = 60.3 R.sub.4 = 21.0 d.sub.4 = 15.0 R.sub.5 = 21.0 d.sub.5 = 1.5 n.sub.3 = 1.7552 νd.sub.3 = 27.5 R.sub.6 = -9.0 2nd d.sub.6 = 0.7 n.sub.4 = 1.713 νd.sub.4 = 53.9 member R.sub.7 = 9.0 (B) d.sub.7 = 0.5 R.sub.8 = -9.0 d.sub.8 = 0.8 n.sub.5 = 1.713 νd.sub.5 = 53.9 R.sub.9 = 4.6 d.sub.9 = 16.5 R.sub.10 = -51.0 d.sub.10 = 2.0 n.sub.6 = 1.62374 νd.sub.6 = 47.0 R.sub.11 = -13.32 3rd d.sub.11 = 0.1 member R.sub.12 = 105.0 (C) d.sub.12 = 0.6 n.sub.7 = 1.74 νd.sub.7 = 28.2 R.sub.13 = 17.0 d.sub.13 = 3.2 n.sub.8 = 1.50032 νd.sub.8 = 81.9 R.sub.14 = -20.28 __________________________________________________________________________ where R 1 , R 2 , . . . are the radii of curvature of the individual surfaces, d 1 , d 2 , . . . are the axial thickness or spacing of individual elements, WD is the axial distance from the object to the first surface of the lens system, n 1 , n 2 , . . . are the refractive indexes of the individual elements and νd 1 , νd 2 , . . . are the Abbe numbers of individual elements.