US 4,066,339 AGrant
Optometer Eyepiece
Issue Date:1978-01-03
•2 Claims
•1 Drawing Sheets
Abstract
A four-component eyepiece for an optometer has an eye relief of about 117mm and is substantially free of chromatic aberration.
Metadata
Assignee
- American Optical Corporation
Inventor
- Arthur H. Shoemaker
Application Information
Application Number:US 705856&
Filing Date:1976-07-16
Priority Date:1976-07-16
Art Unit:257
Classifications
IPC:
G02B 300G02B 934
Field of Search:
350175 E;220
Patent Drawings (1 sheets)
Description
Background of the Invention
This invention relates to an eyepiece and more particularly to an optometer eyepiece having four components.
The Drawing
FIG. 1 is an optical diagram of an eyepiece viewed transverse to the optical axis.
Description of the Invention
Referring to FIG. 1, an optometer eyepiece is diagrammatically shown with optically-aligned lenses I, II, III and IV. The first component I is a biconcavo negative singlet, the second component II is a plano-convex positive singlet, the third component III is a biconvex positive singlet and the fourth component IV is a biconvex positive doublet. The eyepiece provides an imaging distance providing an eye relief of about 117mm.
The parameters of the eyepiece according to the present invention are set forth in Table I with axial thicknesses of successive lens components designated T.sub.1 to T.sub.5 and the successive axial spaces from the first component of the eyepiece to the observer's eye are designated S.sub.1 to S.sub.4. The successive lens radii are designated R.sub.1 to R.sub.9 with a minus sign (-) indicating surfaces whose center of curvature lies on the eye side of their vertices. Refractive indices and Abbe numbers of the glasses in the successive lenses are absolute values designated ND.sub.1 to ND.sub.5 and .nu..sub.1 to .nu..sub.5 respectively.
A specific embodiment of the present invention wherein x is equal to 117mm and has the following values with radii, spacings and thicknesses being in millimeters.
Claims
What is claimed is:
1. A four component optometer eyepiece being substantially free of chromatic aberration comprising a biconcave negative singlet I, a plano-convex positive singlet II, a biconvex positive singlet III and a biconvex positive doublet IV all aligned in sequence along an optical axis and having the values set forth below with axial thicknesses of the successive lens components being designated T.sub.1 to T.sub.5, successive axial spaces from the first component to an observer's eye being designated S.sub.1 to S.sub.4, successive lens radii being designated R.sub.1 to R.sub.9 where the minus sign (-) indicates surfaces whose center of curvature lies on an observer's side of their vertices, refractive indices and Abbe numbers are absolute values designated ND.sub.1 to ND.sub.5 and .nu..sub.1 to .nu..sub.5, respectively, Thick- Index of ness Refraction Abbe Lens Radius(R) (T) Spacing(S) (ND) No. ( ) ______________________________________ R.sub.1 = 0.90598x T.sub.1 = 1.58< I R.sub.2 = 0.034188x ND.sub.1 <1.60 .nu..sub.1 =61 0.90598x S.sub.1 = R.sub.3 = 0.28222x 100x T.sub.2 = 1.58< II R.sub.4 = 0.051282x ND.sub.2 <1.60 .nu..sub.2 =61 1.6036x S.sub.2 = R.sub.5 = 0.0008547x 1.5231x T.sub.3 = 1.58< III R.sub.6 = 0.068376x ND.sub.3 <1.60 .nu..sub.3 =61 0.89786x S.sub.3 = R.sub.7 = 0.17239x -1.8352x T.sub.4 = 1.58< R.sub.8 = 0.08547x ND.sub.4 <1.60 .nu..sub.4 =61 IV 0.42966x T.sub.5 = 1.77< R.sub.9 = 0.059829x ND.sub.5 <1.79 .nu..sub.5 =26 1.1479x S.sub.4 = 0.9982x and x is 115 to 119mm. ______________________________________
2. The eyepiece according to claim 1 wherein x is 117mm, ND.sub.1 to ND.sub.4 are 1.589, ND.sub.5 is 1.784, .nu..sub.1 to .nu..sub.4 are 61.12 and .nu..sub.5 is 25.76.
Patent Citations (2)
| Patent | Date | Inventor | Cited By |
|---|---|---|---|
| US2637245 | 1953-05-01 | Ludewig | |
| US3352620 | 1967-11-01 | Scidmore et al. |