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:
Dec. 30, 1986
Filed:
Jun. 01, 1984
Rino E Kunz, Steinmaur, CH;
Gretag Aktiengesellschaft, Regensdorf, CH;
Abstract
Focusing of a light beam on an object is effected by two mutually complementary techniques: in the first technique the beam spot on the object is reproduced on several measuring diaphragms arranged at different distances from the image plane and the light not blocked by the measuring diaphragms is evaluated for the detection of the focal point. This technique is highly sensitive and reacts rapidly. It is used for the continuous setting and resetting of focusing. The second technique utilizes the phenomenon of 'speckling'. Herein the light back scattered by the beam spot is evaluated for its granulation and optimum focusing determined as a function of the maximum coarseness of granulation. This second technique is insensitive to alignment and is thus used to calibrate the first technique. Both methods together yield a highly sensitive, precise and stable focusing system satisfying all practical requirements to a high degree.