Patent US3752560A successfully refreshed from Google Patents.
US3752560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microscopes incorporating incident-light dark ground illumination systems
Assignee: Vickers Ltd
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Filing: 1971-12-28
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Granted: 1973-08-14
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Expires: 1991-12-28
Abstract
Abstract An incident-light dark ground illumination system for a microscope includes an optical element having at one side an inlet region through which an axially directed light beam is admitted so as to be reflected by a first reflecting surface, at an opposite side of the element, towards a second reflecting surface which surrounds the inlet region and reflects the light back again so that it leaves the element as an output beam surrounding the first reflecting surface. A reflector device having a transparent central area, for transmitting light from an objective to an eyepiece of the microscope, and a nontransmitting peripheral reflecting area surrounding the central area, receives the output beam obliquely so as to produce therefrom an annular reflected beam for delivery to an annular input face of an apertured microscope condenser.
Inventors
- 👤 A Lunn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:08
CPC Classifications
G; G02; G02B; G02B21/00; G02B21/06; G02B21/08; G02B21/082
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
212 words
For use with a microscope having an eyepiece and equipped with an objective and an apertured condenser which has an annular input face and is arranged coaxially with the objective, an incident-light dark ground illumination system comprising an optical element which has an optical axis and is formed with an inlet region at one side of the element to admit light of a given illuminating beam directed towards that one side along said optical axis, and also has a first reflecting surface arranged at an opposite side of the element to receive light admitted by way of said inlet region, and a second reflecting surface arranged at said one side of the element and surrounding said inlet region to receive light of said given beam reflected from the first reflecting surface and to reflect such received light out of the element at said opposite side thereof as an output beam surrounding the first reflecting surface, and the system also comprising a reflector device having a transparent central area, for transmitting light from said objective to said eyepiece, and a non-transmitting peripheral reflecting area which surrounds said central area snd is mounted obliquely to said output beam to produce therefrom a reflected beam, of annular cross-section, for delivering to said annular input face.
Claim 2
Dependent Claim
212 words
For use with a microscope having an eyepiece and equipped with an objective and an apertured condenser which has an annular input face and is arranged coaxially with the objective, an incident-light dark ground illumination system comprising an optical element which has an optical axis and is formed with an inlet region at one side of the element to admit light of a given illuminating beam directed towards that one side along said optical axis, and also has a first reflecting surface arranged at an opposite side of the element to receive light admitted by way of said inlet region, and a second reflecting surface arranged at said one side of the element and surrounding said inlet region to receive light of said given beam reflected from the first reflecting surface and to reflect such received light out of the element at said opposite side thereof as an output beam surrounding the first reflecting surface, and the system also comprising a reflector device having a transparent central area, for transmitting light from said objective to said eyepiece, and a non-transmitting peripheral reflecting area which surrounds said central area snd is mounted obliquely to said output beam to produce therefrom a reflected beam, of annular cross-section, for delivering to said annular input face.
Claim 3
Dependent Claim
44 words
An illumination system according to claim 1, wherein said first and second reflecting surfaces are cylindrically symmetrical about said optical axis, and the first reflecting surface is convex towards said inlet region and the second reflecting surface is concave towards the first reflecting surface.
Claim 4
Dependent Claim
36 words
An illumination system according to claim 2, wherein the first reflecting surface has a focal point and the second reflecting surface has a focal point which coincides with the focal point of the first reflecting surface.
Claim 5
Dependent Claim
47 words
An illumination system according to claim 1, further comprising a first iriS diaphragm defining an aperture, on said optical axis, from which said given illuminating beam emanates, and a lens mounted between the aperture and the element at a position such that said output beam is collimated.
Claim 6
Dependent Claim
65 words
An illumination system according to claim 1, further comprising a first iris diaphragm defining an aperture, on said optical axis, from which said given illuminating beam emanates, a lens mounted between the aperture and the element at a position such that said output beam is collimated, and a second iris diaphragm defining an aperture, on said optical axis, between the first diaphragm and the lens.
Claim 7
Dependent Claim
94 words
An illumination system according to claim 1, further comprising a first iris diaphragm defining an aperture, on said optical axis, from which said given illuminating beam emanates, a lens mounted between the aperture and the element at a position such that said output beam is collimated, a second iris diaphragm defining an aperture, on said optical axis, upstream of the first iris diaphragm, and a field lens mounted adjacent to said second iris diaphragm for converging light from an image of a source formed at the second iris diaphragm towards the first iris diaphragm.
Claim 8
Dependent Claim
22 words
An illumination system according to claim 1, wherein said optical element is mounted so as to be removable from the illumination system.
Claim 9
Dependent Claim
18 words
An illumination system according to claim 1, wherein said central area of the reflector device is partially reflecting.
Claim 10
Dependent Claim
18 words
An illumination system according to claim 1, wherein said central area of the reflector device is totally transparent.
Claim 11
Dependent Claim
30 words
An illumination system according to claim 1, in combination with a lamp and a lamp condenser mounted between the lamp and said optical element for providing said given illuminating beam.
Claim 12
Dependent Claim
74 words
An illumination system according to claim 1, further comprising such an apertured condenser mounted in the system so as to receive said reflected beam coaxially upon its annular input face, and such a microscope objective mounted in the aperture of the condenser with its back towards the reflector device so that the condenser surrounds it coaxially and substantially none of the light of the said reflected beam enters the objective through the back thereof.
Claim 13
Dependent Claim
96 words
An illumination system according to claim 11, wherein said first and second reflecting surfaces are cylindrically symmetrical about said optical axis, the first reflecting surface has a focal point and is convex towards said inlet region, the second reflecting surface, being concave towards said first reflecting surface, has a focal point which coincides with that of said first reflecting surface and the ratio of the aperture of said given beam to the aperture of said output beam is equal to the ratio of the focal length of said objective to the focal length of said condenser.
Claim 14
Dependent Claim
25 words
An illumination system according to claim 11, wherein said condenser and said microscope objective are mounted so as to be removable from the illumination system.
Claim 15
Dependent Claim
35 words
A microscope comprising an eyepiece and equipped with an illumination system as claimed in claim 11, the illumination system being so mounted with respect to the rest of the microscope as to be removable therefrom.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |