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:
Sep. 29, 1992
Filed:
Oct. 10, 1990
Hobart A Whitman, III, Asheville, NC (US);
Other;
Abstract
An optical sighting instrument having a main optical path including an objective lens, an eyepiece lens and a beamsplitter for combining or superimposing images. At least three image planes are defined with reference to the main optical path and the beamsplitter, and at least one of the three image planes is optically superimposed with the other two by the combining effect of the beamsplitter. Movable indicia elements are positioned in two of the image planes, and a fixed indicia element is positioned in the third one of the image planes. As a result, images of all three of the indicia elements are superimposed for viewing through the eyepiece lens, and the image of the fixed indicia element serves as a sighting reference. Illustratively, one of the movable indicia elements is a magnetic compass, the other of the movable indicia elements is a magnetic declination adjustment, and the fixed indicia element is a cross-hair sight. A pair of polarizers adjustable in relative orientation may be provided and positioned for varying the intensity either of the image of one of the indicia elements or the intensity of the object image. A lamp may be included for illuminating at least one of the indicia elements through the beamsplitter, while the beamsplitter prevents its direct light from reaching the eyepiece lens. The magnetic compass may be in the form of a sphere, and a field-flattener lens is positioned in front of the compass sphere so that the surface appears flat.