Optical: systems and elements – Lens – With viewed object or viewed field illumination
Patent
1992-06-29
1993-08-24
Ben, Loha
Optical: systems and elements
Lens
With viewed object or viewed field illumination
359672, 359721, G02B 2702
Patent
active
052394166
ABSTRACT:
A two lens stand magnifier having variable degrees of magnification of an object at a constant distance from an observer is disclosed. A permanently mounted plus lens and a movably mounted minus lens are arranged on a stand such that the plus lens is a constant distance away from the object to be magnified. As the minus lens is moved relative to the positive lens, magnification of an object located on the opposite side of the plus lens from the minus lens varies while the image stays substantially in focus at the constant distance from the observer. Defocus of the image during movement is avoided by the choice of the lens powers as well as the spacing of the range of movement of the minus lens relative to the plus lens.
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Ben Loha
Optical Designs, Inc.
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