US3560781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corpuscular beam microscope apparatus
Assignee: Max-Planck-Gesellschaft zur Förderung der Wissenschaften eV
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Filing: 1967-07-27
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Granted: 1971-02-02
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Expires: 1987-07-27
Abstract
Abstract The beam condenser located in an electron or ion microscope between the beam source and the objective lens comprises at least two lenses, namely a first condenser lens which produces a reduced image of the beam source, and a last condenser lens which produces a reduced image of an aperture diaphragm upon the object plane defined by the objective lens. Within such an arrangement, the first condenser lens comprises a plurality of lens pole shoe systems that can be selectively placed into active position of axial alignment with the beam source and the objective lens. The pole shoe systems have respectively different imaging lengths but have the diameter of their lens bore as well as the width and axial position of their lens gap, so adapted to one another as to maintain an invariable axial position of the source image produced by the first condenser lens, regardless of which one of the pole shoe systems is placed into active position at a time. This affords selecting different radiation (illumination) apertures for one and the same illuminated area of the object without the necessity of changing the focal lengths of the other lenses; and it permits adjusting the size of the illuminated area of the object independently of the magnitude of the illumination aperture of the object.
Inventors
- 👤 Wolfgang Dieter Riecke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:53
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/09; H01J37/10; H01J37/14; H01J37/141; H01J37/147; H01J37/15; H01J37/153
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
152 words
Corpuscular beam apparatus, comprising in axial alignment a corpuscular beam source, condenser lens means with a first condenser lens facing the source for producing a reduced image thereof, and an objective lens defining an object plane, said first condenser lens comprising a fixed magnetic circuit structure and a plurality of lens pole shoe systems selectively placeable into active position relative to said fixed structure so as to be axially aligned with said source and said objective lens, each of said pole shoe systems having a central bore for the passage of the electron beam and an interpole lens gap, and said pole shoe systems having respectively different image distances and having the diameter of said bore and the width and axial position of said lens gap adapted to maintain the axial position of said source imaGe substantially invariable regardless of which of said pole shoe systems is placed into said active position.
Claim 2
Dependent Claim
152 words
Corpuscular beam apparatus, comprising in axial alignment a corpuscular beam source, condenser lens means with a first condenser lens facing the source for producing a reduced image thereof, and an objective lens defining an object plane, said first condenser lens comprising a fixed magnetic circuit structure and a plurality of lens pole shoe systems selectively placeable into active position relative to said fixed structure so as to be axially aligned with said source and said objective lens, each of said pole shoe systems having a central bore for the passage of the electron beam and an interpole lens gap, and said pole shoe systems having respectively different image distances and having the diameter of said bore and the width and axial position of said lens gap adapted to maintain the axial position of said source imaGe substantially invariable regardless of which of said pole shoe systems is placed into said active position.
Claim 3
Dependent Claim
168 words
Corpuscular beam apparatus according to claim 1, comprising a corpuscular beam source, a first condenser lens producing a reduced image of said source, an apertured diaphragm coaxially following said first condenser lens in the beam direction, further condenser lens means comprising a last condenser lens to produce a reduced image of the diaphragm aperture on an object plane, an objective lens defining said object plane, said first condenser lens having a plurality of lens pole shoe systems selectively placeable into active position of coaxial alignment with said last condenser lens and objective lens, said pole shoe systems having respectively different image distances and having each a central pole shoe bore and an interpole lens gap, and said pole shoe systems having the diameter of said bore and the width and axial position of said lens gap adapted to each other so as to maintain the axial position of said source image substantially invariable regardless of which one of said pole shoe systems is placed into said active position.
Claim 4
Dependent Claim
57 words
In apparatus according to claim 2, said first condenser having its main electron-optical planes substantially coincide with the lens center; and said pole shoe systems of said first condenser lens differing from each other substantially in the axial position of said respective lens gaps to thereby compensate for differences in the axial position of said source image.
Claim 5
Dependent Claim
63 words
In apparatus according to claim 2, said first condenser having an axially extended lens field as compared with its distance from said further condenser lens means; and said pole shoe systems of said first condenser lens differing from each other substantially in the axial positions of said respective lens gaps to thereby compensate for differences in the axial position of said source image.
Claim 6
Dependent Claim
59 words
In apparatus according to claim 2, said bore diameter and lends gap width in at least two of said pole shoe systems being in the same order of magnitude as the bore diameter and gap width respectively of said objective lens, and said first condenser having when in operation an excitation for at least approximately the minimal focal length.
Claim 7
Dependent Claim
28 words
In apparatus according to claim 1, all of said pole shoe systems of said first condenser lens having the same ratio of lens gap width to bore diameter.
Claim 8
Dependent Claim
37 words
In apparatus according to claim 2, said last condenser lens forming a lens assembly distinct from that of said objective lens and having a focal plane substantially coincident with the entrance pupil plane of said objective lens.
Claim 9
Dependent Claim
17 words
In apparatus according to claim 2, said objective lens having prefield which forms said last condenser lens.
Claim 10
Dependent Claim
53 words
In apparatus according to claim 2, said further condenser lens means comprising another condenser lens located between said first and said last condenser lenses and of longer focal length than said latter condenser lenses so as to transfer said source image at least approximately to the entrance pupil plane of said objective lens.
Claim 11
Dependent Claim
30 words
In apparatus according to claim 9, said other condenser lens having a lens gap width and a lens bore diameter whose respective sizes are of the same order of magnitude.
Claim 12
Dependent Claim
30 words
In apparatus according to claim 10, said other condenser lens having a lens gap width and a lens bore diameter of the same order of magnitude as its focal length.
Claim 13
Dependent Claim
37 words
In apparatus according to claim 2, said diaphragm being spaced from the entrance pupil plane of said objective lens a distance in the order of magnitude of 100 times the focal length of said last condenser lens.
Claim 14
Dependent Claim
46 words
Apparatus according to claim 1, comprising a holder structure displaceable relative to said lenses in a plane perpendicular to the lens axis, said pole shoe systems being mounted on said holder structure for selectively placing said systems to the active position by displacing said holder structure.
Claim 15
Dependent Claim
43 words
In apparatus according to claim 13, said holder structure comprising a turntable having an axis of rotation spaced from said lens axis and parallel thereto, whereby rotational displacement of said turntable places said pole shoe systems into and out of said active position.
Claim 16
Dependent Claim
17 words
Apparatus according to claim 14, comprising an electric drive coupled with said turntable for rotating the latter.
Claim 17
Dependent Claim
46 words
In apparatus according to claim 13, said first condenser lens comprising a magnetic circuit assembly, said holder structure being displaceably mounted on said assembly to form a structural unit together therewith, and said unit being displaceable as a whole for adjustment transversely of the beam axis.
Claim 18
Dependent Claim
29 words
Apparatus according to claim 1, comprising a radiation aperture diaphragm in the entrance pupil plane of said objective lens for determining the irradiation aperture of the object being imaged.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |