Claims
- 1. A magnifier lens comprising, from a front, eye side to a rear object side:
- (i) a front, positive power lens element having at least one aspheric surface;
- (ii) a middle, negative power lens element accepting light from said front, positive power lens element, wherein said front, positive power lens element and said middle, negative power lens element in combination contain at least one diffractive surface; and
- (iii) a rear, meniscus lens element accepting light from said middle, negative power lens element, said rear, meniscus lens element having front and rear refractive surfaces, both of which are concave toward the object side, said rear refractive surface being (1) positionable within 5 mm of an associated object to be viewed from the eye side and (2) is an aspheric surface of negative power.
- 2. A magnifier lens according to claim 1 wherein said middle, negative power lens element is a meniscus lens element.
- 3. A magnifier lens according to claim 2 wherein said middle, negative power lens element is concave towards the eye side and is cemented to said front, positive power lens element.
- 4. A magnifier lens according to claim 1 wherein each of said front, positive power lens element and said middle, negative power lens element has a respective Abbe V-number and, the Abbe V-number of said front, positive power lens element is greater than the Abbe V-number of said middle, negative power lens element.
- 5. A magnifier lens according to claim 1 wherein said diffractive surface is on the object side facing surface of said middle, negative power lens element.
- 6. A magnifier lens according to claim 1 wherein said diffractive surface is on the eye side facing surface of said middle, negative power lens element.
CROSS REFERENCE TO RELATED APPLICATION
This application is related to commonly assigned, copending U.S. applications, Ser. No. 08/964,484, entitled AN IMPROVED MAGNIFIER LENS, in the name of Joseph R. Bietry, filed concurrently herewith, and Ser. No. 08/562,666, entitled, OPTICAL MAGNIFIER in names of Joseph R. Bietry, Lee Estelle and Paul Luddington, filed on Nov. 27, 1995, now U.S. Pat. No. 5,703,721.
US Referenced Citations (7)
Non-Patent Literature Citations (2)
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