Wide-field and wide-aperture optical system, notably designed for a night channel for periscopes, and periscope fitted out with such an optical system
First Claim
1. A binocular device having an optical system which includes two lens groups, a forward lens a forward group and a rear lens group with the forward lens group closer to a viewing location of an observer with respect to said rear group, wherein said rear group includes a bonded doublet having a plane rear face comprising a convergent convex lens bonded to a divergent lens, said lenses of said bonded doublet having different and complementary dispersions to compensate for chromatism, the focal length of said doublet ranging from 0.85F to 1.05F, where F is the focal length of said binocular device.
1 Assignment
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Accused Products
Abstract
The field of the disclosure is that of enlarging optical lenses and, more precisely, binocular optical systems designed to be inserted into the night-time channel of an observation system, between a light intensifier tube and an observer'"'"'s eyes. The disclosure can be applied especially to observation instruments for armored vehicles and, notably, periscopes for tanks. The disclosed optical system for a binocular device is of the type constituted by two groups, a forward group and a rear group, the rear group being constituted by a bonded doublet with plane rear face comprising a convergent convex lens bonded to a divergent lens, the lenses of the bonded doublet having different and complementary dispersions to compensate for the chromatism, and the focal length of the doublet ranging from 0.85F to 1.05F, where F is the focal length of the binocular device.
17 Citations
10 Claims
- 1. A binocular device having an optical system which includes two lens groups, a forward lens a forward group and a rear lens group with the forward lens group closer to a viewing location of an observer with respect to said rear group, wherein said rear group includes a bonded doublet having a plane rear face comprising a convergent convex lens bonded to a divergent lens, said lenses of said bonded doublet having different and complementary dispersions to compensate for chromatism, the focal length of said doublet ranging from 0.85F to 1.05F, where F is the focal length of said binocular device.
Specification