Patent US3707327A successfully refreshed from Google Patents.
US3707327A
Expired / Lapsed
US
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Magnifier with optical contrast equalizer
Assignee: Braun GmbH
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Filing: 1970-08-05
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Granted: 1972-12-26
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Expires: 1990-08-05
Abstract
Abstract A magnifying apparatus having a projection lamp with a preferably small filament, a concave reflector mounted for movement along the optical axis of the apparatus, a transparent medium mounted in the path of the light rays produced by the projection lamp, the concave reflector forming an image of the filament on the transparent medium which image serves as the effective light source, the planar expansion of the effective light source is adjustable by the axial adjustment of the concave reflector in a continuous fashion.
Inventors
- 👤 Josef Scheibel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:40
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/72
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
102 words
A magnifying apparatus comprising a projection lamp having preferably a small filament, a concave reflector means mounted for movement along the optical axis of the apparatus, a light dispersing transparent medium mounted in the path of the light rays produced by said projection lamp and at a predetermined fixed axial distance from said lamp, said concave reflector means forming an image of said filament on said transparent medium, said image serving as the effective light source, means operable for adjusting the planar expansion of said effective light source by affecting the axial adjustment of said concave reflector means in a continuous fashion.
Claim 2
Dependent Claim
102 words
A magnifying apparatus comprising a projection lamp having preferably a small filament, a concave reflector means mounted for movement along the optical axis of the apparatus, a light dispersing transparent medium mounted in the path of the light rays produced by said projection lamp and at a predetermined fixed axial distance from said lamp, said concave reflector means forming an image of said filament on said transparent medium, said image serving as the effective light source, means operable for adjusting the planar expansion of said effective light source by affecting the axial adjustment of said concave reflector means in a continuous fashion.
Claim 3
Dependent Claim
24 words
The magnifying apparatus as claimed in claim 1, wherein said transparent medium for the forming of said effective light source comprises a dispersion glass.
Claim 4
Dependent Claim
75 words
The magnifying apparatus as claimed in claim 1, further including means operatively coupled to said concave reflector means for adjusting the operating voltage of said projection lamp, whereby each change of the illuminating intensity of the image with which the negative is projected into the magnifying plane of said apparatus and depending from the planar expansion of said effective light source is accompanied by a corresponding change in the operating voltage of the projection lamp.
Claim 5
Dependent Claim
38 words
The magnifying apparatus as claimed in claim 3, wherein said last mentioned means comprises a variable resistor means, a current source and an energizing circuit for said projection lamp, said variable resistor being connected into said energizing circuit.
Claim 6
Dependent Claim
76 words
The magnifying apparatus as claimed in claim 3, wherein said last-mentionEd means for adjusting the operating voltage of said projection lamp comprises step switch means operatively coupled to said concave reflector means, an energizing circuit for said projection lamp including a source of operating voltage supply, a plurality of resistors connected into said energizing circuits and coupled to said stepped switch means for variably adjusting the current flowing in said energizing circuit to said projection lamp.
References Cited (Backward Citations)
US1633228A
Cited
US3227039A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-26 | 1976-06-26 | 1976-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-26 | 1980-06-26 | 1980-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-26 | 1984-06-26 | 1984-12-26 | $7700.00 | Window Closed / Lapsed |