Patent US3880501A successfully refreshed from Google Patents.
US3880501A
Expired / Lapsed
US
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Optical system for objective refractor for the eye
Assignee: Tropel Inc
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Filing: 1974-05-17
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Granted: 1975-04-29
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Expires: 1994-05-17
Abstract
Abstract An optical system for an objective refractor for the eye uses a source of light and a reticle for forming the light in a pattern, and a polarizing beam splitter directs a polarized portion of the light along a light path including a quarter-wave plate. Light reflected from the retina of the eye is directed back along the light path to the polarizing beam splitter, and a polarized portion of the reflected light is oriented by the quarter-wave plate to pass through the polarizing beam splitter on an output path directed away from the source. A light responsive device in the output path produces a usable output as a function of the focus of the reflected pattern, and the optical system can be applied to both manual and automatic refractors.
Inventors
- 👤 Charles R Munnerlyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:44
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/14; A61B3/15; A61B3/156; A61B3/103
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
180 words
In an optical system for an objective refractor for the eye including a source of radiant energy formed in a pattern directed along a path aligned with said eye, optical elements along said path for varying the angle of incidence of said radiant energy on said eye, and a detector for receiving radiant energy reflected from the retina of said eye for producing a useable output as a function of the focus of said reflected radiant energy, the improvement comprising: a. a polarizing beam splitter arranged for receiving said radiant energy from off the axis of said path and directing a polarized portion of said radiant energy along said path through said optical elements toward said eye, said radiant energy reflected from said eye travelling back along said path and being incident on said polarizing beam splitter; and b. means between said optical elements and said eye for altering said polarization of said radiant energy so said polarization of said polarized radiant energy reflected from said eye is oriented to pass straight through said polarizing beam splitter to said detector.
Claim 2
Dependent Claim
180 words
In an optical system for an objective refractor for the eye including a source of radiant energy formed in a pattern directed along a path aligned with said eye, optical elements along said path for varying the angle of incidence of said radiant energy on said eye, and a detector for receiving radiant energy reflected from the retina of said eye for producing a useable output as a function of the focus of said reflected radiant energy, the improvement comprising: a. a polarizing beam splitter arranged for receiving said radiant energy from off the axis of said path and directing a polarized portion of said radiant energy along said path through said optical elements toward said eye, said radiant energy reflected from said eye travelling back along said path and being incident on said polarizing beam splitter; and b. means between said optical elements and said eye for altering said polarization of said radiant energy so said polarization of said polarized radiant energy reflected from said eye is oriented to pass straight through said polarizing beam splitter to said detector.
Claim 3
Dependent Claim
14 words
The system of claim 1 wherein said polarization altering means is a quarter-wave plate.
Claim 4
Dependent Claim
25 words
The system of claim 2 wherein said quarter-wave plate is oriented relative to said polarizing beam splitter to produce the maximum of said useable output.
Claim 5
Dependent Claim
40 words
The system of claim 3 wherein said quarter-wave plate is oriented for rotating the polarization of said radiant energy reflected from said eye by about 90* relative to said radiant energy directed toward said eye by said polarizing beam splitter.
Claim 6
Dependent Claim
32 words
The system of claim 1 including another polarizing beam splitter arranged for initially polarizing a portion of said radiant energy and directing polarized radiant energy to said first mentioned polarizing beam splitter.
Claim 7
Dependent Claim
84 words
The system of claim 1 wherein said polarization altering means is a quarter-wave plate and including a reticle formed as a rotatably driven, slotted drum coaxial with said path for forming said radiant energy into said pattern, a mask positioned between said polarizing beam splitter and said detector and having a pattern correspondinG to said reticle pattern, and means for angularly adjusting said polarizing beam splitter, quarter-wave plate, and said mask together around said path axis for rotating said pattern relative to said eye.
Claim 8
Dependent Claim
32 words
The system of claim 6 including another polarizing beam splitter arranged for initially polarizing a portion of said radiant energy and directing polarized radiant energy to said first mentioned polarizing beam splitter.
Claim 9
Dependent Claim
25 words
The system of claim 7 wherein said quarter-wave plate is oriented relative to said polarizing beam splitter to produce the maximum of said useable output.
Claim 10
Dependent Claim
40 words
The systm of claim 8 wherein said quarter-wave plate is oriented for rotating the polarization of said radiant energy reflected from said eye by about 90* relative to said radiant energy directed toward said eye by said polarizing beam splitter.
Claim 11
Dependent Claim
14 words
The system of claim 6 including a computer receiving said output from said detector.
Claim 12
Dependent Claim
31 words
The system of claim 10 including means controlled by said computer for accomplishing said angular adjustment of said polarizing beam splitter, said quarter-wave plate, and said mask around said path axis.
Claim 13
Dependent Claim
32 words
The system of claim 11 including another polarizing beam splitter arranged for initially polarizing a portion of said radiant energy and directing polarized radiant energy to said first mentioned polarizing beam splitter.
Claim 14
Dependent Claim
57 words
The system of claim 12 wherein said quarter-wave plate is oriented relative to said polarizing beam splitter to produce the maximum of said useable output, and also oriented for rotating the polarization of said radiant energy reflected from said eye by about 90* relative to said radiant energy directed toward said eye by said polarizing beam splitter.
References Cited (Backward Citations)
US3524702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |