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:
Feb. 03, 1976
Filed:
Jan. 03, 1974
William C Bradley, Chelmsford, MA (US);
Allen H Greenleaf, Lexington, MA (US);
Roger K Lee, Jr, Watertown, MA (US);
Itek Corporation, Lexington, MA (US);
Abstract
A system for precisely determining the position of a beam of incident radiation. In one embodiment in the disclosure the system is utilized in an orbiting, Ritchey-Chretien telescope to determine the precise position of the image of a guide star in the focal plane of the telescope. In that embodiment a first reticle plate, having concentric ring reticle lines, is located at the edge of the tangential focal surface of the telescope and outside of the focal area being used for observation. A second reticle plate, having radial reticle lines, is located adjacent to the first reticle plate at the edge of the sagittal focal surface of the telescope and outside of the focal area being used for observation. A relay lens system and an image dissector tube are positioned behind the reticle plates so that light refracted by the reticle plates is passed by the relay lens system to the image dissector tube. A guide star is imaged on the first and second reticle plates. Light in the star image which is imaged onto either an apex or a groove in the reticle plates is split into separate beams in dependence upon the exact position of the image relative to the apex or groove. The position of the guide star image is precisely located first in a coarse position mode and secondly in a fine position mode. In the coarse position mode the image dissector tube aperture is scanned to find the overall locations of the separate beams, and the deflection signals of the image dissector tube at those locations determine the particular apex or groove in each reticle plate upon which the star is imaged. In the fine position mode the amount of light in each of the separate beams formed by the reticle plates is measured by the image dissector tube in a photon counting mode. This determines the exact position of the star image relative to the particular apex or groove in each reticle plate upon which the star image is incident.