Claims
- 1. A light-weight magnification viewer for use with a pair of spectacles comprising: a pair of lens barrels, each of said lens barrels supporting a one element negative eyepiece lens and a two element objective lens forming a doublet, said eyepiece lens and said doublet objective lens for magnifying images, said doublet objective lens having a positive element and a negative element, wherein said negative element of said doublet, and no other element, is formed from a light weight high index glass having a specific gravity of less than 5 grams per cubic centimeter for reducing weight of said doublet, and said negative and positive elements of said objective lens having indices of refraction that differ by more than 15%; and means for mounting said pair of lens barrels to a pair of spectacles for providing higher image quality to a user.
- 2. The magnification viewer of claim 1, wherein said negative element has a dispersion of about .nu..sub.d =25.4 and an index of refraction of about n.sub.d =1.805.
- 3. The magnification viewer of claim 2, wherein said positive element has a dispersion of about .nu..sub.d =64.2 and an index of refraction of about n.sub.d =1.517.
- 4. A light-weight magnification viewer in accordance with claim 1, wherein said negative element of said doublet has a dispersion of about v.sub.d =25.4 and an index of refraction of about n.sub.d =1.805, and said positive element has a dispersion of about v.sub.d =64.2 and an index of refraction of about n.sub.d =1.517 and a thickness of about 6.5 millimeters along the optical center line.
- 5. The light-weight magnification viewer in accordance with claim 4 wherein a biconcave lens is used as the eyepiece lens, and a viewer's working distance is changed solely by using a biconcave lens with an altered exterior radius of curvature.
- 6. The light-weight magnification viewer in accordance with claim 1 wherein a biconcave lens is used as the eyepiece lens, and a viewer's working distance is changed solely by using a biconcave lens with an altered exterior radius of curvature.
- 7. A light-weight magnification viewer for use with a pair of spectacles comprising: a pair of lens barrels, each of said lens barrels supporting a one element biconcave eyepiece lens at one end thereof and a positive compound objective at the other end thereof with an air space therebetween of about 21 millimeters, said eyepiece lens and said objective for magnifying images, said objective having a positive element and a negative element, wherein said negative element of said objective and no other element, is formed from a light weight, high-index glass having a specific gravity of less than 5 grams per cubic centimeter for reducing the weight of said objective, and said negative and positive elements having indices of refraction that differ by more than 15%; and means for mounting said pair of lens barrels to a pair of spectacles for providing higher image quality to a user.
- 8. The light-weight magnification viewer in accordance with claim 7 wherein said indices of refraction differ by less about 18.9%.
- 9. The light-weight magnification viewer in accordance with claim 7 wherein during manufacture a viewer's working distance is changed solely by using an eyepiece lens in which the exterior radius of curvature of the eyepiece lens is changed.
- 10. A method of changing a working distance of a light-weight magnification viewer during assembly, comprising the steps of: supporting a two element objective lens forming a doublet at one end of a lens barrel, said doublet objective lens having a positive element and a negative element, wherein said negative element and no other element, is formed from a light weight high index glass having a specific gravity of less than 5 grams per cubic centimeter for reducing weight of said doublet, and said negative and positive elements having indices of refraction that differ by more than 15%; and mounting a biconcave eyepiece lens at the other end of the barrel having an exterior radius that is selected to set the working distance of the viewer.
CROSS REFERENCE TO RELATED APPLICATION
This is a Continuation Application of Application No. 08/482,647 filed on Jun. 7, 1995, now abandoned, which is a Continuation Application of Application No. 08/114,870, filed on Aug. 31, 1993, now issued U.S. Pat. No. 5,463,500. The invention of the present application is further related to Application No. 08/480,263 filed on Jun. 7, 1995, now issued U.S. Pat. No. 5,790,323, which is a Continuation Application of Application No. 08/115,166 filed on Aug. 31, 1993, now issued U.S. Pat. No. 5,515,209, which was filed on even date and assigned to the same assignee as the assignee of Application No. 08/114,870.
This invention is related to an application entitled "LIGHT-WEIGHT HIGH-MAGNIFICATION CLINICAL VIEWER", Ser. No. 08/115,166, filed on even date herewith and assigned to the same assignee as the assignee of the present invention, now U.S. Pat. No. 5,515,209.
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Foreign Referenced Citations (3)
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57718 |
Sep 1967 |
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Continuations (2)
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482647 |
Jun 1995 |
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114870 |
Aug 1993 |
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