US3876289A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Illumination zoom system for microscopes
Assignee: American Optical Corp
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Filing: 1973-03-26
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Granted: 1975-04-08
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Expires: 1993-03-26
Abstract
Abstract A microscope illumination system having a zoom unit located before the field diaphragm is useful to provide maximum illumination for objectives from 10 to 110X, when using a suitable condenser, without the disadvantages of other systems. The zoom unit comprises a positive lens, a negative lens and a positive lens in series with the two positive lenses connected together and movable with respect to the negative lens along the optical axis as a unit.
Inventors
- 👤 Johannes D Deveer
- 👤 Klaus P Schindl
- 👤 Alois F Dehlink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:15
CPC Classifications
G; G02; G02B; G02B21/00; G02B21/06; G02B21/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
163 words
In a transmitted light microscope illumination system having a light source, an adjustable field diaphragm, an adjustable aperture stop and a condenser having a front focal plane all in optical alignment along an axis, the adjustable aperture stop being positioned near the front focal plane, the improvement comprising an optically compensated zoom unit consisting of positive-negative-positive lens elements, said negative lens element being fixed in position and said positive elements being rigidly coupled and axially movable, said zoom unit being located between the light source and field diaphragm, an intermediate image of said light source being located between the fixed element of said zoom and said field diaphragm, said zoom unit having a substantially stationary back field diaphragm image plane such that the adjustable field diaphragm is filled with light when said aperture stop and said field diaphragm are varied over a wide range and an image of the light source extends completely across the adjustable aperture stop at all positions of adjustment.
Claim 2
Dependent Claim
163 words
In a transmitted light microscope illumination system having a light source, an adjustable field diaphragm, an adjustable aperture stop and a condenser having a front focal plane all in optical alignment along an axis, the adjustable aperture stop being positioned near the front focal plane, the improvement comprising an optically compensated zoom unit consisting of positive-negative-positive lens elements, said negative lens element being fixed in position and said positive elements being rigidly coupled and axially movable, said zoom unit being located between the light source and field diaphragm, an intermediate image of said light source being located between the fixed element of said zoom and said field diaphragm, said zoom unit having a substantially stationary back field diaphragm image plane such that the adjustable field diaphragm is filled with light when said aperture stop and said field diaphragm are varied over a wide range and an image of the light source extends completely across the adjustable aperture stop at all positions of adjustment.
Claim 3
Dependent Claim
37 words
The improvement of claim 1 wherein lens radii (R), thicknesses (T), and spacings (S) are expressed in millimeters and a negative sign indicates lens radii on centers of curvature on the field diaphragm side of said lens:
Claim 4
Dependent Claim
22 words
The improvement of claim 2 further including a collector lens and telescope lens having the values set forth in the following table:
References Cited (Backward Citations)
US2078586A
Cited
US3051052A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |