Patent US3572909A successfully refreshed from Google Patents.
US3572909A
Expired / Lapsed
US
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Infrared optometer
Assignee: United States Department of the Air Force
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Filing: 1969-08-05
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Granted: 1971-03-30
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Expires: 1989-08-05
Abstract
Abstract An infrared optometer device which allows manual or automatic measurement, under either local or remote control, of the refractive index of a man or animal eye in which a collimated beam of light is directed through an infrared filter and by a ''''beam splitter'''' mirror at 90* into a subject''s eye, and the light reflected by the fundus of the eye and exiting back through the lens of the eye from the interior through the beam splitter is converged by a suitable lens toward a focal point at which is located an adjustable photo sensor which detects maximum intensity of the exit beam illumination, calibrated in terms of dioptric change in refractive status. The positioning of the photo sensor in order to detect the maximum intensity of the reflected illumination through the lens of the eye is calibrated in terms of dioptric change in the reflective status. The positioning of the photo sensor is controlled manually or remotely, and completely automatic and continuous operation is contemplated.
Inventors
- 👤 Robert E Vanpatten
- 👤 Paul W Lappin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:08
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/103
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
281 words
An infrared optometer device comprising a support, a concentrated light source, light collimating means carried by said support for projecting a collimated light beam in a predetermined direction away from said light source, an infrared filter plate fixed across said collimated light beam to form an infrared collimated light beam, a beam splitter means fixed across said infrared collimated light beam in 45* angular relation for directing a predetermined portion of said infrared collimated light beam therefrom at 90*, an eyepiece concentrically fixed (in predetermined relation) on the axis of said reflected infrared collimated light beam, a fixed eye inspection position located in said reflected infrared collimated beam on the axis thereof for directing said infrared collimated light beam into the eye of a subject through the cornea and lens of the eye when located in said eye inspection position to converge said reflected infrared beam onto the fundus of a subject''s eye to form an outwardly reflected expanding exit beam from the fundus through the lens of the eye diverging outwardly tHrough said beam splitter mirror, a focusing lens member fixed on the central axis of said exit beam for converging said exit beam toward a focal point proportional in distance to the convergence of the entrance beam between the lens and fundus of the subject''s eye, photosensor means movable in said converging exit beam for receiving the maximum concentrated light energy thereon, means for adjusting said photosensor means in said exit beam toward and away from said focusing lens means to locate the position representing the point of maximum light concentration thereon, and indexing means responsive to movement of said sensor for automatically indicating the maximum light concentration thereon.
Claim 2
Dependent Claim
281 words
An infrared optometer device comprising a support, a concentrated light source, light collimating means carried by said support for projecting a collimated light beam in a predetermined direction away from said light source, an infrared filter plate fixed across said collimated light beam to form an infrared collimated light beam, a beam splitter means fixed across said infrared collimated light beam in 45* angular relation for directing a predetermined portion of said infrared collimated light beam therefrom at 90*, an eyepiece concentrically fixed (in predetermined relation) on the axis of said reflected infrared collimated light beam, a fixed eye inspection position located in said reflected infrared collimated beam on the axis thereof for directing said infrared collimated light beam into the eye of a subject through the cornea and lens of the eye when located in said eye inspection position to converge said reflected infrared beam onto the fundus of a subject''s eye to form an outwardly reflected expanding exit beam from the fundus through the lens of the eye diverging outwardly tHrough said beam splitter mirror, a focusing lens member fixed on the central axis of said exit beam for converging said exit beam toward a focal point proportional in distance to the convergence of the entrance beam between the lens and fundus of the subject''s eye, photosensor means movable in said converging exit beam for receiving the maximum concentrated light energy thereon, means for adjusting said photosensor means in said exit beam toward and away from said focusing lens means to locate the position representing the point of maximum light concentration thereon, and indexing means responsive to movement of said sensor for automatically indicating the maximum light concentration thereon.
Claim 3
Independent Claim
91 words
A device as set forth in claim l in which the photosensor includes an opaque screen, means supporting the screen normal to the axis of converging exit beam and includes a small light admitting aperture concentric to the axis of the exit beam with said photosensor located concentrically behind the aperture to receive the proportion of the concentration of light in the exit beam entering the aperture, and means for moving the screen in the exit beam to admit the strongest light concentration through the aperture to register on the photosensor.
Claim 4
Dependent Claim
50 words
Apparatus as in claim 2 including a pointer on said screen movable therewith and a scale fixed on the support for registration of the pointer thereon to denote the position of the screen at the location where the photosensor receives the maximum degree of light concentration from the exit beam.
Claim 5
Dependent Claim
43 words
A device as set forth in claim 3 including micrometer screw means carried by the support and engaging said screen for parallel movement thereof along the axis of exit with the axis of the aperture concentric to the axis of the exit beam.
Claim 6
Dependent Claim
37 words
Apparatus as set forth in claim 4 including calibrated recording means carried by said support and indicating marking means fixed to said screen for continuously recording the movements of said screen by said micrometer screw adjusting means.
References Cited (Backward Citations)
US2385503A
Cited
US2367855A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |