US5247318A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fundus camera for photography using a fluorescent agent
Assignee: Topcon Corp
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Filing: 1991-12-10
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Granted: 1993-09-21
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Expires: 2011-12-10
Abstract
Abstract The fundus camera of this invention for taking photographs by fluorescence comprises an exciter filter 7 in an illuminating optical system 1, and a barrier filter 16 in a photographic optical system 2. A member 11 for eliminating harmful reflected light from an objective lens 13 is also provided in the illuminating optical system 1. This member 11 for eliminating harmful reflected light comprises dark spots 21, 22, which transmit light below a lower wavelength limit, and cut out light above the lower wavelength limit, of the barrier filter 16.
Inventors
- 👤 Haruhiko Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:58
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/14; A61B3/15; A61B3/156
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
140 words
A fundus camera for taking photographs using a fluorescent agent, the camera comprising: an illuminating optical system; a photographic optical system; an objective lens facing an eye of a subject, the objective lens being located in the photographic optical system; an exciter filter located in the illuminating optical system for transmitting illuminating light with wavelengths within a certain range to excite the fluorescent agent; a barrier filter located in the photographic optical system for transmitting fluorescence excited by the illuminating light, the barrier filter having a lower wavelength limit; a member located in the illuminating optical system for transmitting the illuminating light with wavelengths below the lower wavelength limit, and for cutting out the illuminating light with wavelengths above the lower wavelength limit, so that the illuminating light reflected by the objective lens is cut out by the barrier filter.
Claim 2
Dependent Claim
140 words
A fundus camera for taking photographs using a fluorescent agent, the camera comprising: an illuminating optical system; a photographic optical system; an objective lens facing an eye of a subject, the objective lens being located in the photographic optical system; an exciter filter located in the illuminating optical system for transmitting illuminating light with wavelengths within a certain range to excite the fluorescent agent; a barrier filter located in the photographic optical system for transmitting fluorescence excited by the illuminating light, the barrier filter having a lower wavelength limit; a member located in the illuminating optical system for transmitting the illuminating light with wavelengths below the lower wavelength limit, and for cutting out the illuminating light with wavelengths above the lower wavelength limit, so that the illuminating light reflected by the objective lens is cut out by the barrier filter.
Claim 3
Dependent Claim
46 words
The fundus camera according to claim 1, wherein said member has a first dark spot for eliminating harmful reflected light from a first surface of the objective lens, and a second dark spot for eliminating harmful reflected light from a second surface of the objective lens.
Claim 4
Dependent Claim
22 words
The fundus camera according to claim 2, wherein the first and second dark spots are located on opposite sides of the member.
Claim 5
Dependent Claim
150 words
A fundus camera for taking photographs using a fluorescent agent, the camera comprising: an illuminating optical system; a photographic optical system; an objective lens facing a patient's eye, the objective lens being located in the photographic optical system; an exciter filter located in the illuminating optical system for transmitting illuminating light with wavelengths within a certain range to excite the fluorescent agent; a barrier filter located in the photographic optical system for transmitting fluorescence excited by the illuminating light, the barrier filter having a lower wavelength limit, the illuminating light including a small amount of light with wavelengths higher than said lower wavelength limit; a member located in the illuminating optical system for cutting out said small amount of light, and for transmitting the illuminating light with wavelengths below the lower wavelength limit, so that the illuminating light reflected by the objective lens is cut out by the barrier filter.
Claim 6
Dependent Claim
150 words
A fundus camera for taking photographs using a fluorescent agent, the camera comprising: an illuminating optical system; a photographic optical system; an objective lens facing a patient's eye, the objective lens being located in the photographic optical system; an exciter filter located in the illuminating optical system for transmitting illuminating light with wavelengths within a certain range to excite the fluorescent agent; a barrier filter located in the photographic optical system for transmitting fluorescence excited by the illuminating light, the barrier filter having a lower wavelength limit, the illuminating light including a small amount of light with wavelengths higher than said lower wavelength limit; a member located in the illuminating optical system for cutting out said small amount of light, and for transmitting the illuminating light with wavelengths below the lower wavelength limit, so that the illuminating light reflected by the objective lens is cut out by the barrier filter.
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) | 1996-09-20 | 1997-03-22 | 1997-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-20 | 2001-03-22 | 2001-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-20 | 2005-03-22 | 2005-09-21 | $7700.00 | Window Closed / Lapsed |