Browse Prior Art Database

IMPROVED COMPENSATOR FOR COS 4TH CORRECTION IN CENTER REGISTERED, REDUCTION-/ENLARGEMENT OPTICS

IP.com Disclosure Number: IPCOM000027012D
Original Publication Date: 1994-Dec-31
Included in the Prior Art Database: 2004-Apr-07
Document File: 2 page(s) / 69K

Publishing Venue

Xerox Disclosure Journal

Abstract

Of the factors affecting relative illumination at an image plane, the most well known is the cosine (cos) variation caused by the projection lens wherein the illumination at the image plane is proportional to the COS-

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 87% of the total text.

Page 1 of 2

XEROX DISCLOSURE JOURNAL

IMPROVED COMPENSATOR FOR Proposed Classification COS 4TH CORRECTION IN CENTER
REGISTERED, REDUCTION-
Int. Cl. G03b ENLARGEMENT OPTICS
Dominick J.
Maiorano

US. C1.350/266

A

XEROX DISCLOSURE JOURNAL - Vol. 19, No. 6 November/December 1994 465

[This page contains 1 picture or other non-text object]

Page 2 of 2

IMPROVED COMPENSATOR FOR COS 4TH CORRECTION IN CENTER REGISTERED, REDUCTION/ENLARGEMENT OPTICS

(Cont'd)

Of the factors affecting relative illumination at an image plane, the most well known is the cosine (cos) variation caused by the projection lens wherein the illumination at the image plane is proportional to the COS~ of the angle between the optical axis and the field beam. The figure shows a portion of a center registered imaging system with a COS~ blocker in the optical path. Blocker 2 lies at a fixed position along optical axis 4. Reflected light from an object passes from left to right through the aperture 5 of lens 6 and is partially vignetted by blocker 2. At unity magnification (viewed from full field image point B) the correction is as required. However, for enlargement (point A) the blocker is out of the aperture before the full field point is reached and thus there is no correction beyond the 0.7 field position. For the reduction case (point C) the correction is that the blocker never clears the aperture therefore optimum correction never occurs. In order to improve correction through magnification, the blocker is moved al...