Browse Prior Art Database

Optical Comparator

IP.com Disclosure Number: IPCOM000076742D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Hauke, FE: AUTHOR [+2]

Abstract

Any difference between the outline contour of a three-dimensional object and a previously prepared two-dimensional spatial filter master of an ideal sample, is indicated by a light "bloom" at the point of difference.

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 100% of the total text.

Page 1 of 2

Optical Comparator

Any difference between the outline contour of a three-dimensional object and a previously prepared two-dimensional spatial filter master of an ideal sample, is indicated by a light "bloom" at the point of difference.

A spatial filter, representing the Fourier transform of an ideal sample, is prepared on a transparent medium such as photographic film by existing methods. For example, the transform of the ideal sample, illuminated by a collimated monochromatic light source, is formed at the rear focal point of a converging lens L1 and recorded on photographic film placed in the image plane. This spatial filter is then inserted between converging lenses L1 and L2 of Fig. 1, at the coincident focal point. A processed image is then formed in the image plane for observation by photodetector, film, TV, etc. A typical processed image, representing the differences between the contours of the object and the idea sample recorded by the filter, is shown in Fig. 2.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]