Browse Prior Art Database

Optical Referencing System

IP.com Disclosure Number: IPCOM000093302D
Original Publication Date: 1967-Aug-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Woodard, OC: AUTHOR

Abstract

This optical sensing apparatus determines the deviation of an article from a pair of coordinate X-Y reference axes in the plane of the article. There are provided independent devices for superimposing upon the projected image of the article, which is to be scanned, an image of the reference coordinate axes. Thus the combined images can be simultaneously scanned.

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Optical Referencing System

This optical sensing apparatus determines the deviation of an article from a pair of coordinate X-Y reference axes in the plane of the article. There are provided independent devices for superimposing upon the projected image of the article, which is to be scanned, an image of the reference coordinate axes. Thus the combined images can be simultaneously scanned.

Article 10, such as a semiconductor chip, is retained on substrate 11 and illuminated by light source 12. The reflective image of the chip is projected by lens system 13 onto beam splitter 14. The latter transmits and reflects the chip image respectively along paths 15 and 16. Simultaneously, referencing device 17 projects onto beam splitter 14 a light image of the coordinate X-Y reference axes. Device 17 comprises light 18 applied to plate 19 having formed in it aperture 20 in the configuration of the reference axes. The image of 20 is projected through lens 21 onto beam splitter 14. This transmits and reflects the image of the reference axes respectively along optical paths 15 and 16. Thus, images of the reference axes are superimposed upon image planes 22 and 23 of the respective split images of article 10.

The article image and the reference axis image in plane 22 can then be scanned by photocell scanning device 24. The latter has movement relative to the image in a direction perpendicular to the image of the Y axis. The article image and reference axis image in plane 23 can...