Virtual image superposing comparator

Michael E. Buchtel

doi:10.1117/12.145572

28 May 1993 Virtual image superposing comparator

Michael E. Buchtel

Proceedings Volume 1821, Industrial Applications of Optical Inspection, Metrology, and Sensing; (1993) https://doi.org/10.1117/12.145572
Event: Applications in Optical Science and Engineering, 1992, Boston, MA, United States

Abstract

A virtual image superposing comparator is described which can be used to classify scratch widths, dig diameters and dig densities when verifying the surface quality of optical components. The magnified virtual image of an apparent defect is visually superposed anywhere on the viewing plane of a complete set of large scale standards in a common visual field. By positioning the virtual image of a defect next to or between any corresponding standard, it is possible to make direct, comparative measurements. The density of digs is verified by visually superposing the circular array of the standards over separated digs or groups of digs and summing the classes of digs appearing within the array. Unlike the current, full scale, scratch and dig surface quality standards, the large scale scratch and dig standards can be objectively calibrated by conventional methods and can be accurately and inexpensively reproduced. A derivation of infinity for the 'standard' eye; a coefficient for system scale factor and system magnifying power; an analysis of the effect of relative object spacing, tilt and contrast on comparative measurement; and two surface defect slide charts for expediting the scratch and dig area density computations specified in Military standard specifications are described.

Citation Download Citation

Michael E. Buchtel "Virtual image superposing comparator", Proc. SPIE 1821, Industrial Applications of Optical Inspection, Metrology, and Sensing, (28 May 1993); https://doi.org/10.1117/12.145572

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available