The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 26, 1999
Filed:
Sep. 04, 1997
Gary R Noyes, Los Angeles, CA (US);
Raytheon Company, El Segundo, CA (US);
Abstract
The focal length of an objective lens system is substantially equal at two wavelengths: one within the visible spectrum and one within an eyesafe IR spectrum centered about 1.54 .mu.m; the lens is essentially achromatic throughout the entire visible spectrum (0.45 .mu.m -0.70 .mu.m) and is well-corrected for other monochromatic aberrations (spherical aberration, coma, astigmatism, field curvature, and distortion). By having an objective lens that is common to both optical paths (visual and laser) and has the property of having essentially the same focal length and essentially the same angular deviation for the two optical paths upon lens decentration, then a practical mechanism can be included in the opto-mechanical design of a laser rangefinder to adjust the x and y decentration of the objective lens to accomplish a corresponding x and y adjustment of the system boresight. One specific embodiment is a cemented triplet in which the front lens element is bi-convex and is formed of a crown glass having a relatively high index of refraction (n) and a moderately high inverse relative dispersion (V); the rear element is substantially plano convex and is formed of a crown glass having a relatively low index of refraction and a relatively high inverse relative dispersion; and the middle lens element is bi-concave and is formed of an anomalous dispersion flint glass having an index of refraction intermediate that of the front and rear elements and an inverse relative dispersion that is substantially below that of those other two elements, with partial relative dispersion being displaced from the 'normal' line by at least twice and preferably at least six times the distance associated with the normal glasses forming the two convergent elements.