US5748372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High numerical aperture and long working distance objective system using diffraction-type optical elements
Assignee: Olympus Corp
•
Filing: 1996-04-17
•
Granted: 1998-05-05
•
Expires: 2016-04-17
Abstract
Abstract The invention provides a high-magnification and high-NA objective having a long working distance, which is corrected for various aberrations, especially chromatic aberrations over a wide wavelength range and allowed to have an aligning pupil position without making much use of cemented lenses and anomalous dispersion glass. The objective comprises a first lens group G1 including a meniscus lens concave on the object side and having a positive power as a whole, two optical elements of the diffraction type (DOEs), and a second lens group G2 including at least one cemented lens, and satisfies the condition for ensuring the edge thickness of the front lens as well as either one of two conditions for making effective correction for longitudinal chromatic aberration and chromatic aberration of magnification.
Inventors
- 👤 Junichi Kitagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:04
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/42; G02B27/4205; G02B27/4211; G02B21/00; G02B21/02; G02B27/4272; G02B27/4277
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
64 words
An objective system comprising: a first diffraction type of optical element having a diffraction action; a second diffraction type of optical element located at an image side of said first diffraction type of optical element; and at least one cemented lens having a cemented surface, wherein said at least one cemented lens is located between said first and second diffraction type of optical elements.
Claim 2
Dependent Claim
64 words
An objective system comprising: a first diffraction type of optical element having a diffraction action; a second diffraction type of optical element located at an image side of said first diffraction type of optical element; and at least one cemented lens having a cemented surface, wherein said at least one cemented lens is located between said first and second diffraction type of optical elements.
Claim 3
Dependent Claim
35 words
An objective system according to claim 1, further comprising a meniscus lens located at an object side of said first diffraction type of optical element, wherein said meniscus lens is concave on said object side.
Claim 4
Dependent Claim
47 words
An objective system according to claim 1, further comprising a lens group having a positive power wherein said lens group includes a meniscus lens located at an object side of said first diffraction type of optical element, wherein said meniscus lens is concave on said object side.
Claim 5
Dependent Claim
92 words
An objective system comprising, in order from an object side: a first lens group including a meniscus lens concave on the object side, said first lens group having a positive power as a whole; a first diffraction type of optical element having a diffraction action; and a second lens group divided into a front sub-group including at least one cemented lens having a cemented surface and a rear sub-group having at least one lens, wherein a second diffraction type of optical element is located between said front sub-group and said rear sub-group.
Claim 6
Dependent Claim
92 words
An objective system comprising, in order from an object side: a first lens group including a meniscus lens concave on the object side, said first lens group having a positive power as a whole; a first diffraction type of optical element having a diffraction action; and a second lens group divided into a front sub-group including at least one cemented lens having a cemented surface and a rear sub-group having at least one lens, wherein a second diffraction type of optical element is located between said front sub-group and said rear sub-group.
Claim 7
Dependent Claim
42 words
An objective system according to claim 1, 2, 3 or 4, wherein at least one of said first and second diffraction type of optical elements is in the form of a transparent member having a diffraction surface of sawtooth shape in section.
Claim 8
Dependent Claim
43 words
An objective system according to claim 1, 2, 3 or 4, wherein at last one of said first and second diffraction type of optical elements is in the form of a transparent member having a diffraction surface of stepped sawtooth shape in section.
Claim 9
Dependent Claim
41 words
An objective system according to claim 2, 3, or 4 which further satisfies the following condition: 0.5<R/t<5 where R is the radius of curvature of said meniscus lens on the image side, and t is the thickness of said meniscus lens.
Claim 10
Dependent Claim
67 words
An objective system according to claim 1, 2, 3 or 4, wherein, at least one of said first and said second diffractive type optical elements satisfies the following condition: D.sub.d /D>0.8 where D d is a diameter of a bundle of marginal rays at a surface of the corresponding diffraction type of optical element and D is a maximum height of marginal rays through said objective system.
Claim 11
Dependent Claim
73 words
An objective system according to claim 1, 2, 3 or 4, wherein, at least one of said first and said second diffractive type optical elements satisfies the following condition: (h·f)/(L·I)>0.07 where f is the focal length of the objective system, h is a maximum ray height at a surface of the corresponding diffraction type of optical element, L is the parfocal length, and I is the maximum image height at a sample surface.
Claim 12
Dependent Claim
52 words
An objective system according to claim 2, 3, or 4, which further satisfies the following condition: (W·H)/(L·f)>0.005 where W is the working distance, L is the parfocal length, H is a marginal ray height at said concave surface of said meniscus lens, and f is a focal length of the objective system.
Claim 13
Dependent Claim
34 words
An objective system according to claim 1, 2, 3 or 4, wherein one of said first and second diffraction type of optical elements has a positive power and the other has a negative power.
Claim 14
Dependent Claim
40 words
An objective system according to claim 11, which further satisfies the following condition: 30<f.sub.d /f<150 where f and f d are the focal lengths of the objective system and said diffraction type of optical element having a positive power, respectively.
Claim 15
Dependent Claim
34 words
An objective system according to claim 1, 2, 3 or 4, wherein an Abbe's number difference Δν between adjacent lenses of said at least one cemented lens is given by the following condition: Δν>20.
Claim 16
Dependent Claim
52 words
An objective system according to claim 1, 2, 3 or 4, wherein at least one positive surface and at least one negative surface are located at an image side of an actual pupil position, said actual pupil being located at a position at which an off-axis principal ray intersects an optical axis.
Claim 17
Dependent Claim
59 words
An objective system according to claim 1, 2, 3 or 4, further comprising a cemented lens group, wherein said cemented lens group comprises a cemented lens located at a position nearer to said image side than a position of said second diffraction type of optical element and on a side of said objective system nearest to said image side.
References Cited (Backward Citations)
DE2850574A1
Cited
SU1053055A1
Cited
SU1151905A1
Cited
JPH021109A
Cited
US5013133A
Cited
US5170207A
Cited
US5148314A
Cited
US5257133A
Cited
US5151823A
Cited
US5268790A
Cited
US5287218A
Cited
US5436763A
Cited
JPH06194605A
Cited
US5371570A
Cited
US5444569A
Cited
JPH06331898A
Cited
JPH06347700A
Cited
US5555479A
Cited
US5526183A
Cited
US5543966A
Cited
US5493441A
Cited
US5446588A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-04 | 2001-11-03 | 2002-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-04 | 2005-11-03 | 2006-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-04 | 2009-11-03 | 2010-05-05 | $7700.00 | Window Closed / Lapsed |